xfs_btree_check_block contains debugging knobs. With XFS_DEBUG setting up,
turn on the debugging knob can trigger the assert of xfs_btree_islastblock,
test script as follows:
while true
do
mount $disk $mountpoint
fsstress -d $testdir -l 0 -n 10000 -p 4 >/dev/null
echo 1 > /sys/fs/xfs/sda/errortag/btree_chk_sblk
sleep 10
umount $mountpoint
done
Kick off fsstress and only *then* turn on the debugging knob. If it
happens that the knob gets turned on after the cntbt lookup succeeds
but before the call to xfs_btree_islastblock, then we *can* end up in
the situation where a previously checked btree block suddenly starts
returning EFSCORRUPTED from xfs_btree_check_block. Kaboom.
Darrick give a very detailed explanation as follows:
Looking back at commit 27d9ee577d, I think the point of all this was
to make sure that the cursor has actually performed a lookup, and that
the btree block at whatever level we're asking about is ok.
If the caller hasn't ever done a lookup, the bc_levels array will be
empty, so cur->bc_levels[level].bp pointer will be NULL. The call to
xfs_btree_get_block will crash anyway, so the "ASSERT(block);" part is
pointless.
If the caller did a lookup but the lookup failed due to block
corruption, the corresponding cur->bc_levels[level].bp pointer will also
be NULL, and we'll still crash. The "ASSERT(xfs_btree_check_block);"
logic is also unnecessary.
If the cursor level points to an inode root, the block buffer will be
incore, so it had better always be consistent.
If the caller ignores a failed lookup after a successful one and calls
this function, the cursor state is garbage and the assert wouldn't have
tripped anyway. So get rid of the assert.
Fixes: 27d9ee577d ("xfs: actually check xfs_btree_check_block return in xfs_btree_islastblock")
Signed-off-by: Guo Xuenan <guoxuenan@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
This series fixes a bug in the refcount code where we don't merge
records correctly if the refcount is hovering around MAXREFCOUNT. This
fixes regressions in xfs/179 when fsdax is enabled. xfs/179 itself will
be modified to exploit the bug through the pagecache path.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Merge tag 'maxrefcount-fixes-6.2_2022-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into xfs-6.2-mergeD
xfs: fix broken MAXREFCOUNT handling
This series fixes a bug in the refcount code where we don't merge
records correctly if the refcount is hovering around MAXREFCOUNT. This
fixes regressions in xfs/179 when fsdax is enabled. xfs/179 itself will
be modified to exploit the bug through the pagecache path.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
* tag 'maxrefcount-fixes-6.2_2022-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
xfs: estimate post-merge refcounts correctly
xfs: hoist refcount record merge predicates
Upon enabling fsdax + reflink for XFS, xfs/179 began to report refcount
metadata corruptions after being run. Specifically, xfs_repair noticed
single-block refcount records that could be combined but had not been.
The root cause of this is improper MAXREFCOUNT edge case handling in
xfs_refcount_merge_extents. When we're trying to find candidates for a
refcount btree record merge, we compute the refcount attribute of the
merged record, but we fail to account for the fact that once a record
hits rc_refcount == MAXREFCOUNT, it is pinned that way forever. Hence
the computed refcount is wrong, and we fail to merge the extents.
Fix this by adjusting the merge predicates to compute the adjusted
refcount correctly.
Fixes: 3172725814 ("xfs: adjust refcount of an extent of blocks in refcount btree")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Xiao Yang <yangx.jy@fujitsu.com>
Hoist these multiline conditionals into separate static inline helpers
to improve readability and set the stage for corruption fixes that will
be introduced in the next patch.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Xiao Yang <yangx.jy@fujitsu.com>
xfs log io error will trigger xlog shut down, and end_io worker call
xlog_state_shutdown_callbacks to unpin and release the buf log item.
The race condition is that when there are some thread doing transaction
commit and happened not to be intercepted by xlog_is_shutdown, then,
these log item will be insert into CIL, when unpin and release these
buf log item, UAF will occur. BTW, add delay before `xlog_cil_commit`
can increase recurrence probability.
The following call graph actually encountered this bad situation.
fsstress io end worker kworker/0:1H-216
xlog_ioend_work
->xlog_force_shutdown
->xlog_state_shutdown_callbacks
->xlog_cil_process_committed
->xlog_cil_committed
->xfs_trans_committed_bulk
->xfs_trans_apply_sb_deltas ->li_ops->iop_unpin(lip, 1);
->xfs_trans_getsb
->_xfs_trans_bjoin
->xfs_buf_item_init
->if (bip) { return 0;} //relog
->xlog_cil_commit
->xlog_cil_insert_items //insert into CIL
->xfs_buf_ioend_fail(bp);
->xfs_buf_ioend
->xfs_buf_item_done
->xfs_buf_item_relse
->xfs_buf_item_free
when cil push worker gather percpu cil and insert super block buf log item
into ctx->log_items then uaf occurs.
==================================================================
BUG: KASAN: use-after-free in xlog_cil_push_work+0x1c8f/0x22f0
Write of size 8 at addr ffff88801800f3f0 by task kworker/u4:4/105
CPU: 0 PID: 105 Comm: kworker/u4:4 Tainted: G W
6.1.0-rc1-00001-g274115149b42 #136
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 04/01/2014
Workqueue: xfs-cil/sda xlog_cil_push_work
Call Trace:
<TASK>
dump_stack_lvl+0x4d/0x66
print_report+0x171/0x4a6
kasan_report+0xb3/0x130
xlog_cil_push_work+0x1c8f/0x22f0
process_one_work+0x6f9/0xf70
worker_thread+0x578/0xf30
kthread+0x28c/0x330
ret_from_fork+0x1f/0x30
</TASK>
Allocated by task 2145:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
__kasan_slab_alloc+0x54/0x60
kmem_cache_alloc+0x14a/0x510
xfs_buf_item_init+0x160/0x6d0
_xfs_trans_bjoin+0x7f/0x2e0
xfs_trans_getsb+0xb6/0x3f0
xfs_trans_apply_sb_deltas+0x1f/0x8c0
__xfs_trans_commit+0xa25/0xe10
xfs_symlink+0xe23/0x1660
xfs_vn_symlink+0x157/0x280
vfs_symlink+0x491/0x790
do_symlinkat+0x128/0x220
__x64_sys_symlink+0x7a/0x90
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Freed by task 216:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
kasan_save_free_info+0x2a/0x40
__kasan_slab_free+0x105/0x1a0
kmem_cache_free+0xb6/0x460
xfs_buf_ioend+0x1e9/0x11f0
xfs_buf_item_unpin+0x3d6/0x840
xfs_trans_committed_bulk+0x4c2/0x7c0
xlog_cil_committed+0xab6/0xfb0
xlog_cil_process_committed+0x117/0x1e0
xlog_state_shutdown_callbacks+0x208/0x440
xlog_force_shutdown+0x1b3/0x3a0
xlog_ioend_work+0xef/0x1d0
process_one_work+0x6f9/0xf70
worker_thread+0x578/0xf30
kthread+0x28c/0x330
ret_from_fork+0x1f/0x30
The buggy address belongs to the object at ffff88801800f388
which belongs to the cache xfs_buf_item of size 272
The buggy address is located 104 bytes inside of
272-byte region [ffff88801800f388, ffff88801800f498)
The buggy address belongs to the physical page:
page:ffffea0000600380 refcount:1 mapcount:0 mapping:0000000000000000
index:0xffff88801800f208 pfn:0x1800e
head:ffffea0000600380 order:1 compound_mapcount:0 compound_pincount:0
flags: 0x1fffff80010200(slab|head|node=0|zone=1|lastcpupid=0x1fffff)
raw: 001fffff80010200 ffffea0000699788 ffff88801319db50 ffff88800fb50640
raw: ffff88801800f208 000000000015000a 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88801800f280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88801800f300: fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88801800f380: fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88801800f400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88801800f480: fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
Disabling lock debugging due to kernel taint
Signed-off-by: Guo Xuenan <guoxuenan@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Fix uaf in xfs_trans_ail_delete during xlog force shutdown.
In commit cd6f79d1fb ("xfs: run callbacks before waking waiters in
xlog_state_shutdown_callbacks") changed the order of running callbacks
and wait for iclog completion to avoid unmount path untimely destroy AIL.
But which seems not enough to ensue this, adding mdelay in
`xfs_buf_item_unpin` can prove that.
The reproduction is as follows. To ensure destroy AIL safely,
we should wait all xlog ioend workers done and sync the AIL.
==================================================================
BUG: KASAN: use-after-free in xfs_trans_ail_delete+0x240/0x2a0
Read of size 8 at addr ffff888023169400 by task kworker/1:1H/43
CPU: 1 PID: 43 Comm: kworker/1:1H Tainted: G W
6.1.0-rc1-00002-gc28266863c4a #137
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 04/01/2014
Workqueue: xfs-log/sda xlog_ioend_work
Call Trace:
<TASK>
dump_stack_lvl+0x4d/0x66
print_report+0x171/0x4a6
kasan_report+0xb3/0x130
xfs_trans_ail_delete+0x240/0x2a0
xfs_buf_item_done+0x7b/0xa0
xfs_buf_ioend+0x1e9/0x11f0
xfs_buf_item_unpin+0x4c8/0x860
xfs_trans_committed_bulk+0x4c2/0x7c0
xlog_cil_committed+0xab6/0xfb0
xlog_cil_process_committed+0x117/0x1e0
xlog_state_shutdown_callbacks+0x208/0x440
xlog_force_shutdown+0x1b3/0x3a0
xlog_ioend_work+0xef/0x1d0
process_one_work+0x6f9/0xf70
worker_thread+0x578/0xf30
kthread+0x28c/0x330
ret_from_fork+0x1f/0x30
</TASK>
Allocated by task 9606:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
__kasan_kmalloc+0x7a/0x90
__kmalloc+0x59/0x140
kmem_alloc+0xb2/0x2f0
xfs_trans_ail_init+0x20/0x320
xfs_log_mount+0x37e/0x690
xfs_mountfs+0xe36/0x1b40
xfs_fs_fill_super+0xc5c/0x1a70
get_tree_bdev+0x3c5/0x6c0
vfs_get_tree+0x85/0x250
path_mount+0xec3/0x1830
do_mount+0xef/0x110
__x64_sys_mount+0x150/0x1f0
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Freed by task 9662:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
kasan_save_free_info+0x2a/0x40
__kasan_slab_free+0x105/0x1a0
__kmem_cache_free+0x99/0x2d0
kvfree+0x3a/0x40
xfs_log_unmount+0x60/0xf0
xfs_unmountfs+0xf3/0x1d0
xfs_fs_put_super+0x78/0x300
generic_shutdown_super+0x151/0x400
kill_block_super+0x9a/0xe0
deactivate_locked_super+0x82/0xe0
deactivate_super+0x91/0xb0
cleanup_mnt+0x32a/0x4a0
task_work_run+0x15f/0x240
exit_to_user_mode_prepare+0x188/0x190
syscall_exit_to_user_mode+0x12/0x30
do_syscall_64+0x42/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
The buggy address belongs to the object at ffff888023169400
which belongs to the cache kmalloc-128 of size 128
The buggy address is located 0 bytes inside of
128-byte region [ffff888023169400, ffff888023169480)
The buggy address belongs to the physical page:
page:ffffea00008c5a00 refcount:1 mapcount:0 mapping:0000000000000000
index:0xffff888023168f80 pfn:0x23168
head:ffffea00008c5a00 order:1 compound_mapcount:0 compound_pincount:0
flags: 0x1fffff80010200(slab|head|node=0|zone=1|lastcpupid=0x1fffff)
raw: 001fffff80010200 ffffea00006b3988 ffffea0000577a88 ffff88800f842ac0
raw: ffff888023168f80 0000000000150007 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888023169300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888023169380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888023169400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888023169480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888023169500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
Disabling lock debugging due to kernel taint
Fixes: cd6f79d1fb ("xfs: run callbacks before waking waiters in xlog_state_shutdown_callbacks")
Signed-off-by: Guo Xuenan <guoxuenan@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
I've been running near-continuous integration testing of online fsck,
and I've noticed that once a day, one of the ARM VMs will fail the test
with out of order records in the data fork.
xfs/804 races fsstress with online scrub (aka scan but do not change
anything), so I think this might be a bug in the core xfs code. This
also only seems to trigger if one runs the test for more than ~6 minutes
via TIME_FACTOR=13 or something.
https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfstests-dev.git/tree/tests/xfs/804?h=djwong-wtf
I added a debugging patch to the kernel to check the data fork extents
after taking the ILOCK, before dropping ILOCK, and before and after each
bmapping operation. So far I've narrowed it down to the delalloc code
inserting a record in the wrong place in the iext tree:
xfs_bmap_add_extent_hole_delay, near line 2691:
case 0:
/*
* New allocation is not contiguous with another
* delayed allocation.
* Insert a new entry.
*/
oldlen = newlen = 0;
xfs_iunlock_check_datafork(ip); <-- ok here
xfs_iext_insert(ip, icur, new, state);
xfs_iunlock_check_datafork(ip); <-- bad here
break;
}
I recorded the state of the data fork mappings and iext cursor state
when a corrupt data fork is detected immediately after the
xfs_bmap_add_extent_hole_delay call in xfs_bmapi_reserve_delalloc:
ino 0x140bb3 func xfs_bmapi_reserve_delalloc line 4164 data fork:
ino 0x140bb3 nr 0x0 nr_real 0x0 offset 0xb9 blockcount 0x1f startblock 0x935de2 state 1
ino 0x140bb3 nr 0x1 nr_real 0x1 offset 0xe6 blockcount 0xa startblock 0xffffffffe0007 state 0
ino 0x140bb3 nr 0x2 nr_real 0x1 offset 0xd8 blockcount 0xe startblock 0x935e01 state 0
Here we see that a delalloc extent was inserted into the wrong position
in the iext leaf, same as all the other times. The extra trace data I
collected are as follows:
ino 0x140bb3 fork 0 oldoff 0xe6 oldlen 0x4 oldprealloc 0x6 isize 0xe6000
ino 0x140bb3 oldgotoff 0xea oldgotstart 0xfffffffffffffffe oldgotcount 0x0 oldgotstate 0
ino 0x140bb3 crapgotoff 0x0 crapgotstart 0x0 crapgotcount 0x0 crapgotstate 0
ino 0x140bb3 freshgotoff 0xd8 freshgotstart 0x935e01 freshgotcount 0xe freshgotstate 0
ino 0x140bb3 nowgotoff 0xe6 nowgotstart 0xffffffffe0007 nowgotcount 0xa nowgotstate 0
ino 0x140bb3 oldicurpos 1 oldleafnr 2 oldleaf 0xfffffc00f0609a00
ino 0x140bb3 crapicurpos 2 crapleafnr 2 crapleaf 0xfffffc00f0609a00
ino 0x140bb3 freshicurpos 1 freshleafnr 2 freshleaf 0xfffffc00f0609a00
ino 0x140bb3 newicurpos 1 newleafnr 3 newleaf 0xfffffc00f0609a00
The first line shows that xfs_bmapi_reserve_delalloc was called with
whichfork=XFS_DATA_FORK, off=0xe6, len=0x4, prealloc=6.
The second line ("oldgot") shows the contents of @got at the beginning
of the call, which are the results of the first iext lookup in
xfs_buffered_write_iomap_begin.
Line 3 ("crapgot") is the result of duplicating the cursor at the start
of the body of xfs_bmapi_reserve_delalloc and performing a fresh lookup
at @off.
Line 4 ("freshgot") is the result of a new xfs_iext_get_extent right
before the call to xfs_bmap_add_extent_hole_delay. Totally garbage.
Line 5 ("nowgot") is contents of @got after the
xfs_bmap_add_extent_hole_delay call.
Line 6 is the contents of @icur at the beginning fo the call. Lines 7-9
are the contents of the iext cursors at the point where the block
mappings were sampled.
I think @oldgot is a HOLESTARTBLOCK extent because the first lookup
didn't find anything, so we filled in imap with "fake hole until the
end". At the time of the first lookup, I suspect that there's only one
32-block unwritten extent in the mapping (hence oldicurpos==1) but by
the time we get to recording crapgot, crapicurpos==2.
Dave then added:
Ok, that's much simpler to reason about, and implies the smoke is
coming from xfs_buffered_write_iomap_begin() or
xfs_bmapi_reserve_delalloc(). I suspect the former - it does a lot
of stuff with the ILOCK_EXCL held.....
.... including calling xfs_qm_dqattach_locked().
xfs_buffered_write_iomap_begin
ILOCK_EXCL
look up icur
xfs_qm_dqattach_locked
xfs_qm_dqattach_one
xfs_qm_dqget_inode
dquot cache miss
xfs_iunlock(ip, XFS_ILOCK_EXCL);
error = xfs_qm_dqread(mp, id, type, can_alloc, &dqp);
xfs_ilock(ip, XFS_ILOCK_EXCL);
....
xfs_bmapi_reserve_delalloc(icur)
Yup, that's what is letting the magic smoke out -
xfs_qm_dqattach_locked() can cycle the ILOCK. If that happens, we
can pass a stale icur to xfs_bmapi_reserve_delalloc() and it all
goes downhill from there.
Back to Darrick now:
So. Fix this by moving the dqattach_locked call up before we take the
ILOCK, like all the other callers in that file.
Fixes: a526c85c22 ("xfs: move xfs_file_iomap_begin_delay around") # goes further back than this
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
-Wuninitialized complains about @target in xfsaild_push being
uninitialized in the case where the waitqueue is active but there is no
last item in the AIL to wait for. I /think/ it should never be the case
that the subsequent xfs_trans_ail_cursor_first returns a log item and
hence we'll never end up at XFS_LSN_CMP, but let's make this explicit.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
When -Wstringop-truncation is enabled, the compiler complains about
truncation of the null byte at the end of the xattr name prefix. This
is intentional, since we're concatenating the two strings together and
do _not_ want a null byte in the middle of the name.
We've already ensured that the name buffer is long enough to handle
prefix and name, and the prefix_len is supposed to be the length of the
prefix string without the null byte, so use memcpy here instead.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Every now and then I see fstests failures on aarch64 (64k pages) that
trigger on the following sequence:
mkfs.xfs $dev
mount $dev $mnt
touch $mnt/a
umount $mnt
xfs_db -c 'path /a' -c 'print' $dev
99% of the time this succeeds, but every now and then xfs_db cannot find
/a and fails. This turns out to be a race involving udev/blkid, the
page cache for the block device, and the xfs_db process.
udev is triggered whenever anyone closes a block device or unmounts it.
The default udev rules invoke blkid to read the fs super and create
symlinks to the bdev under /dev/disk. For this, it uses buffered reads
through the page cache.
xfs_db also uses buffered reads to examine metadata. There is no
coordination between xfs_db and udev, which means that they can run
concurrently. Note there is no coordination between the kernel and
blkid either.
On a system with 64k pages, the page cache can cache the superblock and
the root inode (and hence the root dir) with the same 64k page. If
udev spawns blkid after the mkfs and the system is busy enough that it
is still running when xfs_db starts up, they'll both read from the same
page in the pagecache.
The unmount writes updated inode metadata to disk directly. The XFS
buffer cache does not use the bdev pagecache, nor does it invalidate the
pagecache on umount. If the above scenario occurs, the pagecache no
longer reflects what's on disk, xfs_db reads the stale metadata, and
fails to find /a. Most of the time this succeeds because closing a bdev
invalidates the page cache, but when processes race, everyone loses.
Fix the problem by invalidating the bdev pagecache after flushing the
bdev, so that xfs_db will see up to date metadata.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Add a new error injection knob so that we can arbitrarily slow down
pagecache writes to test for race conditions and aberrant reclaim
behavior if the writeback mechanisms are slow to issue writeback. This
will enable functional testing for the ifork sequence counters
introduced in commit 304a68b9c6 ("xfs: use iomap_valid method to
detect stale cached iomaps") that fixes write racing with reclaim
writeback.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Add a new error injection knob so that we can arbitrarily slow down
writeback to test for race conditions and aberrant reclaim behavior if
the writeback mechanisms are slow to issue writeback. This will enable
functional testing for the ifork sequence counters introduced in commit
745b3f76d1 ("xfs: maintain a sequence count for inode fork
manipulations").
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
This patch series fixes a data corruption that occurs in a specific
multi-threaded write workload. The workload combined
racing unaligned adjacent buffered writes with low memory conditions
that caused both writeback and memory reclaim to race with the
writes.
The result of this was random partial blocks containing zeroes
instead of the correct data. The underlying problem is that iomap
caches the write iomap for the duration of the write() operation,
but it fails to take into account that the extent underlying the
iomap can change whilst the write is in progress.
The short story is that an iomap can span mutliple folios, and so
under low memory writeback can be cleaning folios the write()
overlaps. Whilst the overlapping data is cached in memory, this
isn't a problem, but because the folios are now clean they can be
reclaimed. Once reclaimed, the write() does the wrong thing when
re-instantiating partial folios because the iomap no longer reflects
the underlying state of the extent. e.g. it thinks the extent is
unwritten, so it zeroes the partial range, when in fact the
underlying extent is now written and so it should have read the data
from disk. This is how we get random zero ranges in the file
instead of the correct data.
The gory details of the race condition can be found here:
https://lore.kernel.org/linux-xfs/20220817093627.GZ3600936@dread.disaster.area/
Fixing the problem has two aspects. The first aspect of the problem
is ensuring that iomap can detect a stale cached iomap during a
write in a race-free manner. We already do this stale iomap
detection in the writeback path, so we have a mechanism for
detecting that the iomap backing the data range may have changed
and needs to be remapped.
In the case of the write() path, we have to ensure that the iomap is
validated at a point in time when the page cache is stable and
cannot be reclaimed from under us. We also need to validate the
extent before we start performing any modifications to the folio
state or contents. Combine these two requirements together, and the
only "safe" place to validate the iomap is after we have looked up
and locked the folio we are going to copy the data into, but before
we've performed any initialisation operations on that folio.
If the iomap fails validation, we then mark it stale, unlock the
folio and end the write. This effectively means a stale iomap
results in a short write. Filesystems should already be able to
handle this, as write operations can end short for many reasons and
need to iterate through another mapping cycle to be completed. Hence
the iomap changes needed to detect and handle stale iomaps during
write() operations is relatively simple...
However, the assumption is that filesystems should already be able
to handle write failures safely, and that's where the second
(first?) part of the problem exists. That is, handling a partial
write is harder than just "punching out the unused delayed
allocation extent". This is because mmap() based faults can race
with writes, and if they land in the delalloc region that the write
allocated, then punching out the delalloc region can cause data
corruption.
This data corruption problem is exposed by generic/346 when iomap is
converted to detect stale iomaps during write() operations. Hence
write failure in the filesytems needs to handle the fact that the
write() in progress doesn't necessarily own the data in the page
cache over the range of the delalloc extent it just allocated.
As a result, we can't just truncate the page cache over the range
the write() didn't reach and punch all the delalloc extent. We have
to walk the page cache over the untouched range and skip over any
dirty data region in the cache in that range. Which is ....
non-trivial.
That is, iterating the page cache has to handle partially populated
folios (i.e. block size < page size) that contain data. The data
might be discontiguous within a folio. Indeed, there might be
*multiple* discontiguous data regions within a single folio. And to
make matters more complex, multi-page folios mean we just don't know
how many sub-folio regions we might have to iterate to find all
these regions. All the corner cases between the conversions and
rounding between filesystem block size, folio size and multi-page
folio size combined with unaligned write offsets kept breaking my
brain.
However, if we convert the code to track the processed
write regions by byte ranges instead of fileystem block or page
cache index, we could simply use mapping_seek_hole_data() to find
the start and end of each discrete data region within the range we
needed to scan. SEEK_DATA finds the start of the cached data region,
SEEK_HOLE finds the end of the region. These are byte based
interfaces that understand partially uptodate folio regions, and so
can iterate discrete sub-folio data regions directly. This largely
solved the problem of discovering the dirty regions we need to keep
the delalloc extent over.
However, to use mapping_seek_hole_data() without needing to export
it, we have to move all the delalloc extent cleanup to the iomap
core and so now the iomap core can clean up delayed allocation
extents in a safe, sane and filesystem neutral manner.
With all this done, the original data corruption never occurs
anymore, and we now have a generic mechanism for ensuring that page
cache writes do not do the wrong thing when writeback and reclaim
change the state of the physical extent and/or page cache contents
whilst the write is in progress.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
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Merge tag 'xfs-iomap-stale-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs into xfs-6.2-mergeB
xfs, iomap: fix data corruption due to stale cached iomaps
This patch series fixes a data corruption that occurs in a specific
multi-threaded write workload. The workload combined
racing unaligned adjacent buffered writes with low memory conditions
that caused both writeback and memory reclaim to race with the
writes.
The result of this was random partial blocks containing zeroes
instead of the correct data. The underlying problem is that iomap
caches the write iomap for the duration of the write() operation,
but it fails to take into account that the extent underlying the
iomap can change whilst the write is in progress.
The short story is that an iomap can span mutliple folios, and so
under low memory writeback can be cleaning folios the write()
overlaps. Whilst the overlapping data is cached in memory, this
isn't a problem, but because the folios are now clean they can be
reclaimed. Once reclaimed, the write() does the wrong thing when
re-instantiating partial folios because the iomap no longer reflects
the underlying state of the extent. e.g. it thinks the extent is
unwritten, so it zeroes the partial range, when in fact the
underlying extent is now written and so it should have read the data
from disk. This is how we get random zero ranges in the file
instead of the correct data.
The gory details of the race condition can be found here:
https://lore.kernel.org/linux-xfs/20220817093627.GZ3600936@dread.disaster.area/
Fixing the problem has two aspects. The first aspect of the problem
is ensuring that iomap can detect a stale cached iomap during a
write in a race-free manner. We already do this stale iomap
detection in the writeback path, so we have a mechanism for
detecting that the iomap backing the data range may have changed
and needs to be remapped.
In the case of the write() path, we have to ensure that the iomap is
validated at a point in time when the page cache is stable and
cannot be reclaimed from under us. We also need to validate the
extent before we start performing any modifications to the folio
state or contents. Combine these two requirements together, and the
only "safe" place to validate the iomap is after we have looked up
and locked the folio we are going to copy the data into, but before
we've performed any initialisation operations on that folio.
If the iomap fails validation, we then mark it stale, unlock the
folio and end the write. This effectively means a stale iomap
results in a short write. Filesystems should already be able to
handle this, as write operations can end short for many reasons and
need to iterate through another mapping cycle to be completed. Hence
the iomap changes needed to detect and handle stale iomaps during
write() operations is relatively simple...
However, the assumption is that filesystems should already be able
to handle write failures safely, and that's where the second
(first?) part of the problem exists. That is, handling a partial
write is harder than just "punching out the unused delayed
allocation extent". This is because mmap() based faults can race
with writes, and if they land in the delalloc region that the write
allocated, then punching out the delalloc region can cause data
corruption.
This data corruption problem is exposed by generic/346 when iomap is
converted to detect stale iomaps during write() operations. Hence
write failure in the filesytems needs to handle the fact that the
write() in progress doesn't necessarily own the data in the page
cache over the range of the delalloc extent it just allocated.
As a result, we can't just truncate the page cache over the range
the write() didn't reach and punch all the delalloc extent. We have
to walk the page cache over the untouched range and skip over any
dirty data region in the cache in that range. Which is ....
non-trivial.
That is, iterating the page cache has to handle partially populated
folios (i.e. block size < page size) that contain data. The data
might be discontiguous within a folio. Indeed, there might be
*multiple* discontiguous data regions within a single folio. And to
make matters more complex, multi-page folios mean we just don't know
how many sub-folio regions we might have to iterate to find all
these regions. All the corner cases between the conversions and
rounding between filesystem block size, folio size and multi-page
folio size combined with unaligned write offsets kept breaking my
brain.
However, if we convert the code to track the processed
write regions by byte ranges instead of fileystem block or page
cache index, we could simply use mapping_seek_hole_data() to find
the start and end of each discrete data region within the range we
needed to scan. SEEK_DATA finds the start of the cached data region,
SEEK_HOLE finds the end of the region. These are byte based
interfaces that understand partially uptodate folio regions, and so
can iterate discrete sub-folio data regions directly. This largely
solved the problem of discovering the dirty regions we need to keep
the delalloc extent over.
However, to use mapping_seek_hole_data() without needing to export
it, we have to move all the delalloc extent cleanup to the iomap
core and so now the iomap core can clean up delayed allocation
extents in a safe, sane and filesystem neutral manner.
With all this done, the original data corruption never occurs
anymore, and we now have a generic mechanism for ensuring that page
cache writes do not do the wrong thing when writeback and reclaim
change the state of the physical extent and/or page cache contents
whilst the write is in progress.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
* tag 'xfs-iomap-stale-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs:
xfs: drop write error injection is unfixable, remove it
xfs: use iomap_valid method to detect stale cached iomaps
iomap: write iomap validity checks
xfs: xfs_bmap_punch_delalloc_range() should take a byte range
iomap: buffered write failure should not truncate the page cache
xfs,iomap: move delalloc punching to iomap
xfs: use byte ranges for write cleanup ranges
xfs: punching delalloc extents on write failure is racy
xfs: write page faults in iomap are not buffered writes
With the changes to scan the page cache for dirty data to avoid data
corruptions from partial write cleanup racing with other page cache
operations, the drop writes error injection no longer works the same
way it used to and causes xfs/196 to fail. This is because xfs/196
writes to the file and populates the page cache before it turns on
the error injection and starts failing -overwrites-.
The result is that the original drop-writes code failed writes only
-after- overwriting the data in the cache, followed by invalidates
the cached data, then punching out the delalloc extent from under
that data.
On the surface, this looks fine. The problem is that page cache
invalidation *doesn't guarantee that it removes anything from the
page cache* and it doesn't change the dirty state of the folio. When
block size == page size and we do page aligned IO (as xfs/196 does)
everything happens to align perfectly and page cache invalidation
removes the single page folios that span the written data. Hence the
followup delalloc punch pass does not find cached data over that
range and it can punch the extent out.
IOWs, xfs/196 "works" for block size == page size with the new
code. I say "works", because it actually only works for the case
where IO is page aligned, and no data was read from disk before
writes occur. Because the moment we actually read data first, the
readahead code allocates multipage folios and suddenly the
invalidate code goes back to zeroing subfolio ranges without
changing dirty state.
Hence, with multipage folios in play, block size == page size is
functionally identical to block size < page size behaviour, and
drop-writes is manifestly broken w.r.t to this case. Invalidation of
a subfolio range doesn't result in the folio being removed from the
cache, just the range gets zeroed. Hence after we've sequentially
walked over a folio that we've dirtied (via write data) and then
invalidated, we end up with a dirty folio full of zeroed data.
And because the new code skips punching ranges that have dirty
folios covering them, we end up leaving the delalloc range intact
after failing all the writes. Hence failed writes now end up
writing zeroes to disk in the cases where invalidation zeroes folios
rather than removing them from cache.
This is a fundamental change of behaviour that is needed to avoid
the data corruption vectors that exist in the old write fail path,
and it renders the drop-writes injection non-functional and
unworkable as it stands.
As it is, I think the error injection is also now unnecessary, as
partial writes that need delalloc extent are going to be a lot more
common with stale iomap detection in place. Hence this patch removes
the drop-writes error injection completely. xfs/196 can remain for
testing kernels that don't have this data corruption fix, but those
that do will report:
xfs/196 3s ... [not run] XFS error injection drop_writes unknown on this kernel.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Now that iomap supports a mechanism to validate cached iomaps for
buffered write operations, hook it up to the XFS buffered write ops
so that we can avoid data corruptions that result from stale cached
iomaps. See:
https://lore.kernel.org/linux-xfs/20220817093627.GZ3600936@dread.disaster.area/
or the ->iomap_valid() introduction commit for exact details of the
corruption vector.
The validity cookie we store in the iomap is based on the type of
iomap we return. It is expected that the iomap->flags we set in
xfs_bmbt_to_iomap() is not perturbed by the iomap core and are
returned to us in the iomap passed via the .iomap_valid() callback.
This ensures that the validity cookie is always checking the correct
inode fork sequence numbers to detect potential changes that affect
the extent cached by the iomap.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
All the callers of xfs_bmap_punch_delalloc_range() jump through
hoops to convert a byte range to filesystem blocks before calling
xfs_bmap_punch_delalloc_range(). Instead, pass the byte range to
xfs_bmap_punch_delalloc_range() and have it do the conversion to
filesystem blocks internally.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Because that's what Christoph wants for this error handling path
only XFS uses.
It requires a new iomap export for handling errors over delalloc
ranges. This is basically the XFS code as is stands, but even though
Christoph wants this as iomap funcitonality, we still have
to call it from the filesystem specific ->iomap_end callback, and
call into the iomap code with yet another filesystem specific
callback to punch the delalloc extent within the defined ranges.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
xfs_buffered_write_iomap_end() currently converts the byte ranges
passed to it to filesystem blocks to pass them to the bmap code to
punch out delalloc blocks, but then has to convert filesytem
blocks back to byte ranges for page cache truncate.
We're about to make the page cache truncate go away and replace it
with a page cache walk, so having to convert everything to/from/to
filesystem blocks is messy and error-prone. It is much easier to
pass around byte ranges and convert to page indexes and/or
filesystem blocks only where those units are needed.
In preparation for the page cache walk being added, add a helper
that converts byte ranges to filesystem blocks and calls
xfs_bmap_punch_delalloc_range() and convert
xfs_buffered_write_iomap_end() to calculate limits in byte ranges.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
xfs_buffered_write_iomap_end() has a comment about the safety of
punching delalloc extents based holding the IOLOCK_EXCL. This
comment is wrong, and punching delalloc extents is not race free.
When we punch out a delalloc extent after a write failure in
xfs_buffered_write_iomap_end(), we punch out the page cache with
truncate_pagecache_range() before we punch out the delalloc extents.
At this point, we only hold the IOLOCK_EXCL, so there is nothing
stopping mmap() write faults racing with this cleanup operation,
reinstantiating a folio over the range we are about to punch and
hence requiring the delalloc extent to be kept.
If this race condition is hit, we can end up with a dirty page in
the page cache that has no delalloc extent or space reservation
backing it. This leads to bad things happening at writeback time.
To avoid this race condition, we need the page cache truncation to
be atomic w.r.t. the extent manipulation. We can do this by holding
the mapping->invalidate_lock exclusively across this operation -
this will prevent new pages from being inserted into the page cache
whilst we are removing the pages and the backing extent and space
reservation.
Taking the mapping->invalidate_lock exclusively in the buffered
write IO path is safe - it naturally nests inside the IOLOCK (see
truncate and fallocate paths). iomap_zero_range() can be called from
under the mapping->invalidate_lock (from the truncate path via
either xfs_zero_eof() or xfs_truncate_page(), but iomap_zero_iter()
will not instantiate new delalloc pages (because it skips holes) and
hence will not ever need to punch out delalloc extents on failure.
Fix the locking issue, and clean up the code logic a little to avoid
unnecessary work if we didn't allocate the delalloc extent or wrote
the entire region we allocated.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
The following error occurred during the fsstress test:
XFS: Assertion failed: VFS_I(ip)->i_nlink >= 2, file: fs/xfs/xfs_inode.c, line: 2452
The problem was that inode race condition causes incorrect i_nlink to be
written to disk, and then it is read into memory. Consider the following
call graph, inodes that are marked as both XFS_IFLUSHING and
XFS_IRECLAIMABLE, i_nlink will be reset to 1 and then restored to original
value in xfs_reinit_inode(). Therefore, the i_nlink of directory on disk
may be set to 1.
xfsaild
xfs_inode_item_push
xfs_iflush_cluster
xfs_iflush
xfs_inode_to_disk
xfs_iget
xfs_iget_cache_hit
xfs_iget_recycle
xfs_reinit_inode
inode_init_always
xfs_reinit_inode() needs to hold the ILOCK_EXCL as it is changing internal
inode state and can race with other RCU protected inode lookups. On the
read side, xfs_iflush_cluster() grabs the ILOCK_SHARED while under rcu +
ip->i_flags_lock, and so xfs_iflush/xfs_inode_to_disk() are protected from
racing inode updates (during transactions) by that lock.
Fixes: ff7bebeb91 ("xfs: refactor the inode recycling code") # goes further back than this
Signed-off-by: Long Li <leo.lilong@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
This is a simple mechanical transformation done by:
@@
expression E;
@@
- prandom_u32_max
+ get_random_u32_below
(E)
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Reviewed-by: SeongJae Park <sj@kernel.org> # for damon
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
As of now only device names are printed out over __xfs_printk().
The device names are not persistent across reboots which in case
of searching for origin of corruption brings another task to properly
identify the devices. This patch add XFS UUID upon every mount/umount
event which will make the identification much easier.
Signed-off-by: Lukas Herbolt <lukas@herbolt.com>
[sandeen: rebase onto current upstream kernel]
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
When lazysbcount is enabled, fsstress and loop mount/unmount test report
the following problems:
XFS (loop0): SB summary counter sanity check failed
XFS (loop0): Metadata corruption detected at xfs_sb_write_verify+0x13b/0x460,
xfs_sb block 0x0
XFS (loop0): Unmount and run xfs_repair
XFS (loop0): First 128 bytes of corrupted metadata buffer:
00000000: 58 46 53 42 00 00 10 00 00 00 00 00 00 28 00 00 XFSB.........(..
00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000020: 69 fb 7c cd 5f dc 44 af 85 74 e0 cc d4 e3 34 5a i.|._.D..t....4Z
00000030: 00 00 00 00 00 20 00 06 00 00 00 00 00 00 00 80 ..... ..........
00000040: 00 00 00 00 00 00 00 81 00 00 00 00 00 00 00 82 ................
00000050: 00 00 00 01 00 0a 00 00 00 00 00 04 00 00 00 00 ................
00000060: 00 00 0a 00 b4 b5 02 00 02 00 00 08 00 00 00 00 ................
00000070: 00 00 00 00 00 00 00 00 0c 09 09 03 14 00 00 19 ................
XFS (loop0): Corruption of in-memory data (0x8) detected at _xfs_buf_ioapply
+0xe1e/0x10e0 (fs/xfs/xfs_buf.c:1580). Shutting down filesystem.
XFS (loop0): Please unmount the filesystem and rectify the problem(s)
XFS (loop0): log mount/recovery failed: error -117
XFS (loop0): log mount failed
This corruption will shutdown the file system and the file system will
no longer be mountable. The following script can reproduce the problem,
but it may take a long time.
#!/bin/bash
device=/dev/sda
testdir=/mnt/test
round=0
function fail()
{
echo "$*"
exit 1
}
mkdir -p $testdir
while [ $round -lt 10000 ]
do
echo "******* round $round ********"
mkfs.xfs -f $device
mount $device $testdir || fail "mount failed!"
fsstress -d $testdir -l 0 -n 10000 -p 4 >/dev/null &
sleep 4
killall -w fsstress
umount $testdir
xfs_repair -e $device > /dev/null
if [ $? -eq 2 ];then
echo "ERR CODE 2: Dirty log exception during repair."
exit 1
fi
round=$(($round+1))
done
With lazysbcount is enabled, There is no additional lock protection for
reading m_ifree and m_icount in xfs_log_sb(), if other cpu modifies the
m_ifree, this will make the m_ifree greater than m_icount. For example,
consider the following sequence and ifreedelta is postive:
CPU0 CPU1
xfs_log_sb xfs_trans_unreserve_and_mod_sb
---------- ------------------------------
percpu_counter_sum(&mp->m_icount)
percpu_counter_add_batch(&mp->m_icount,
idelta, XFS_ICOUNT_BATCH)
percpu_counter_add(&mp->m_ifree, ifreedelta);
percpu_counter_sum(&mp->m_ifree)
After this, incorrect inode count (sb_ifree > sb_icount) will be writen to
the log. In the subsequent writing of sb, incorrect inode count (sb_ifree >
sb_icount) will fail to pass the boundary check in xfs_validate_sb_write()
that cause the file system shutdown.
When lazysbcount is enabled, we don't need to guarantee that Lazy sb
counters are completely correct, but we do need to guarantee that sb_ifree
<= sb_icount. On the other hand, the constraint that m_ifree <= m_icount
must be satisfied any time that there /cannot/ be other threads allocating
or freeing inode chunks. If the constraint is violated under these
circumstances, sb_i{count,free} (the ondisk superblock inode counters)
maybe incorrect and need to be marked sick at unmount, the count will
be rebuilt on the next mount.
Fixes: 8756a5af18 ("libxfs: add more bounds checking to sb sanity checks")
Signed-off-by: Long Li <leo.lilong@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Clean up resources if resetting the dotdot entry doesn't succeed.
Observed through code inspection.
Fixes: 5838d0356b ("xfs: reset child dir '..' entry when unlinking child")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Andrey Albershteyn <aalbersh@redhat.com>
Metadata files (e.g. realtime bitmaps and quota files) do not show up in
the bulkstat output, which means that scrub-by-handle does not work;
they can only be checked through a specific scrub type. Therefore, each
scrub type calls xchk_metadata_inode_forks to check the metadata for
whatever's in the file.
Unfortunately, that function doesn't actually check the inode record
itself. Refactor the function a bit to make that happen.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
We can handle files that are exactly s_maxbytes bytes long; we just
can't handle anything larger than that.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
CoW forks only exist in memory, which means that they can only ever have
an incore extent tree. Hence they must always be FMT_EXTENTS, so check
this when we're scrubbing them.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Ensure that extents in an inode's CoW fork are not marked as shared in
the refcount btree.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Teach scrub to flag quota files containing unwritten extents.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Enhance the block map scrubber to check delayed allocation reservations.
Though there are no physical space allocations to check, we do need to
make sure that the range of file offsets being mapped are correct, and
to bump the lastoff cursor so that key order checking works correctly.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
When scrub is checking file fork mappings against rmap records and
the rmap record starts before or ends after the bmap record, check the
adjacent bmap records to make sure that they're adjacent to the one
we're checking. This helps us to detect cases where the rmaps cover
territory that the bmaps do not.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
sparse complains that we can return an uninitialized error from this
function and that pag could be uninitialized. We know that there are no
zero-AG filesystems and hence we had to call xchk_bmap_check_ag_rmaps at
least once, so this is not actually possible, but I'm too worn out from
automated complaints from unsophisticated AIs so let's just fix this and
move on to more interesting problems, eh?
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Teach the summary count checker to count the number of free realtime
extents and compare that to the superblock copy.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
If any part of the per-AG summary counter scan loop aborts without
collecting all of the data we need, the scrubber's observation data will
be invalid. Set the incomplete flag so that we abort the scrub without
reporting false corruptions. Document the data dependency here too.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
xfs_rtalloc_query_range scans the realtime bitmap file in order of
increasing file offset, so this caller can take ILOCK_SHARED on the rt
bitmap inode instead of ILOCK_EXCL. This isn't going to yield any
practical benefits at mount time, but we'd like to make the locking
usage consistent around xfs_rtalloc_query_all calls. Make all the
places we do this use the same xfs_ilock lockflags for consistency.
Fixes: 4c934c7dd6 ("xfs: report realtime space information via the rtbitmap")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
It turns out that GETFSMAP and online fsck have had a bug for years due
to their use of ILOCK_SHARED to coordinate their linear scans of the
realtime bitmap. If the bitmap file's data fork happens to be in BTREE
format and the scan occurs immediately after mounting, the incore bmbt
will not be populated, leading to ASSERTs tripping over the incorrect
inode state. Because the bitmap scans always lock bitmap buffers in
increasing order of file offset, it is appropriate for these two callers
to take a shared ILOCK to improve scalability.
To fix this problem, load both data and attr fork state into memory when
mounting the realtime inodes. Realtime metadata files aren't supposed
to have an attr fork so the second step is likely a nop.
On most filesystems this is unlikely since the rtbitmap data fork is
usually in extents format, but it's possible to craft a filesystem that
will by fragmenting the free space in the data section and growfsing the
rt section.
Fixes: 4c934c7dd6 ("xfs: report realtime space information via the rtbitmap")
Also-Fixes: 46d9bfb5e7 ("xfs: cross-reference the realtime bitmap")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
If we tried to repair something but the repair failed with -EDEADLOCK,
that means that the repair function couldn't grab some resource it
needed and wants us to try again. If we try again (with TRY_HARDER) but
still can't get all the resources we need, the repair fails and errors
remain on the filesystem.
Right now, repair returns the -EDEADLOCK to the caller as -EFSCORRUPTED,
which results in XFS_SCRUB_OFLAG_CORRUPT being passed out to userspace.
This is not correct because repair has not determined that anything is
corrupt. If the repair had been invoked on an object that could be
optimized but wasn't corrupt (OFLAG_PREEN), the inability to grab
resources will be reported to userspace as corrupt metadata, and users
will be unnecessarily alarmed that their suboptimal metadata turned into
a corruption.
Fix this by returning zero so that the results of the actual scrub will
be copied back out to userspace.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Repair functions will not return EAGAIN -- if they were not able to
obtain resources, they should return EDEADLOCK (like the rest of online
fsck) to signal that we need to grab all the resources and try again.
Hence we don't need to deal with this case except as a debugging
assertion.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
If the scrub process is sent a fatal signal while we're checking dquots,
the predicate for this will set the error code to -EINTR. Don't then
squash that into -ECANCELED, because the wrong errno turns up in the
trace output.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
If the program calling online fsck is terminated with a fatal signal,
bail out to userspace by returning EINTR, not EAGAIN. EAGAIN is used by
scrubbers to indicate that we should try again with more resources
locked, and not to indicate that the operation was cancelled. The
miswiring is mostly harmless, but it shows up in the trace data.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Convert all the online scrub code to use the Linux slab allocator
functions directly instead of going through the kmem wrappers.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Initialize the check_owner list head so that we don't corrupt the list.
Reduce the scope of the object pointer.
Fixes: 858333dcf0 ("xfs: check btree block ownership with bnobt/rmapbt when scrubbing btree")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Memory allocation usage is the same throughout online fsck -- we want
kernel memory, we have to be able to back out if we can't allocate
memory, and we don't want to spray dmesg with memory allocation failure
reports. Standardize the GFP flag usage and document these requirements.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Teach the AGFL repair function to check each block of the proposed AGFL
against the rmap btree. If the rmapbt finds any mappings that are not
OWN_AG, strike that block from the list.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Currently, the only way to lock an allocation group is to hold the AGI
and AGF buffers. If a repair needs to roll the transaction while
repairing some AG metadata, it maintains that lock by holding the two
buffers across the transaction roll and joins them afterwards.
However, repair is not like other parts of XFS that employ the bhold -
roll - bjoin sequence because it's possible that the AGI or AGF buffers
are not actually dirty before the roll. This presents two problems --
First, we need to redirty those buffers to keep them moving along in the
log to avoid pinning the log tail. Second, a clean buffer log item can
detach from the buffer. If this happens, the buffer type state is
discarded along with the bli and must be reattached before the next time
the buffer is logged. If it is not, the logging code will complain and
log recovery will not work properly.
An earlier version of this patch tried to fix the second problem by
re-setting the buffer type in the bli after joining the buffer to the
new transaction, but that looked weird and didn't solve the first
problem. Instead, solve both problems by logging the buffer before
rolling the transaction.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
While scrubbing an allocation group, we don't need to hold the AGFL
buffer as part of the scrub context. All that is necessary to lock an
AG is to hold the AGI and AGF buffers, so fix all the existing users of
the AGFL buffer to grab them only when necessary.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
While running the online fsck test suite, I noticed the following
assertion in the kernel log (edited for brevity):
XFS: Assertion failed: 0, file: fs/xfs/xfs_health.c, line: 571
------------[ cut here ]------------
WARNING: CPU: 3 PID: 11667 at fs/xfs/xfs_message.c:104 assfail+0x46/0x4a [xfs]
CPU: 3 PID: 11667 Comm: xfs_scrub Tainted: G W 5.19.0-rc7-xfsx #rc7 6e6475eb29fd9dda3181f81b7ca7ff961d277a40
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
RIP: 0010:assfail+0x46/0x4a [xfs]
Call Trace:
<TASK>
xfs_dir2_isblock+0xcc/0xe0
xchk_directory_blocks+0xc7/0x420
xchk_directory+0x53/0xb0
xfs_scrub_metadata+0x2b6/0x6b0
xfs_scrubv_metadata+0x35e/0x4d0
xfs_ioc_scrubv_metadata+0x111/0x160
xfs_file_ioctl+0x4ec/0xef0
__x64_sys_ioctl+0x82/0xa0
do_syscall_64+0x2b/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
This assertion triggers in xfs_dirattr_mark_sick when the caller passes
in a whichfork value that is neither of XFS_{DATA,ATTR}_FORK. The cause
of this is that xchk_directory_blocks only partially initializes the
xfs_da_args structure that is passed to xfs_dir2_isblock. If the data
fork is not correct, the XFS_IS_CORRUPT clause will trigger. My
development branch reports this failure to the health monitoring
subsystem, which accesses the uninitialized args->whichfork field,
leading the the assertion tripping. We really shouldn't be passing
random stack contents around, so the solution here is to force the
compiler to zero-initialize the struct.
Found by fuzzing u3.bmx[0].blockcount = middlebit on xfs/1554.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
When we reserve a delalloc region in xfs_buffered_write_iomap_begin,
we mark the iomap as IOMAP_F_NEW so that the the write context
understands that it allocated the delalloc region.
If we then fail that buffered write, xfs_buffered_write_iomap_end()
checks for the IOMAP_F_NEW flag and if it is set, it punches out
the unused delalloc region that was allocated for the write.
The assumption this code makes is that all buffered write operations
that can allocate space are run under an exclusive lock (i_rwsem).
This is an invalid assumption: page faults in mmap()d regions call
through this same function pair to map the file range being faulted
and this runs only holding the inode->i_mapping->invalidate_lock in
shared mode.
IOWs, we can have races between page faults and write() calls that
fail the nested page cache write operation that result in data loss.
That is, the failing iomap_end call will punch out the data that
the other racing iomap iteration brought into the page cache. This
can be reproduced with generic/34[46] if we arbitrarily fail page
cache copy-in operations from write() syscalls.
Code analysis tells us that the iomap_page_mkwrite() function holds
the already instantiated and uptodate folio locked across the iomap
mapping iterations. Hence the folio cannot be removed from memory
whilst we are mapping the range it covers, and as such we do not
care if the mapping changes state underneath the iomap iteration
loop:
1. if the folio is not already dirty, there is no writeback races
possible.
2. if we allocated the mapping (delalloc or unwritten), the folio
cannot already be dirty. See #1.
3. If the folio is already dirty, it must be up to date. As we hold
it locked, it cannot be reclaimed from memory. Hence we always
have valid data in the page cache while iterating the mapping.
4. Valid data in the page cache can exist when the underlying
mapping is DELALLOC, UNWRITTEN or WRITTEN. Having the mapping
change from DELALLOC->UNWRITTEN or UNWRITTEN->WRITTEN does not
change the data in the page - it only affects actions if we are
initialising a new page. Hence #3 applies and we don't care
about these extent map transitions racing with
iomap_page_mkwrite().
5. iomap_page_mkwrite() checks for page invalidation races
(truncate, hole punch, etc) after it locks the folio. We also
hold the mapping->invalidation_lock here, and hence the mapping
cannot change due to extent removal operations while we are
iterating the folio.
As such, filesystems that don't use bufferheads will never fail
the iomap_folio_mkwrite_iter() operation on the current mapping,
regardless of whether the iomap should be considered stale.
Further, the range we are asked to iterate is limited to the range
inside EOF that the folio spans. Hence, for XFS, we will only map
the exact range we are asked for, and we will only do speculative
preallocation with delalloc if we are mapping a hole at the EOF
page. The iterator will consume the entire range of the folio that
is within EOF, and anything beyond the EOF block cannot be accessed.
We never need to truncate this post-EOF speculative prealloc away in
the context of the iomap_page_mkwrite() iterator because if it
remains unused we'll remove it when the last reference to the inode
goes away.
Hence we don't actually need an .iomap_end() cleanup/error handling
path at all for iomap_page_mkwrite() for XFS. This means we can
separate the page fault processing from the complexity of the
.iomap_end() processing in the buffered write path. This also means
that the buffered write path will also be able to take the
mapping->invalidate_lock as necessary.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
We've been (ab)using XFS_REFC_COW_START as both an integer quantity and
a bit flag, even though it's *only* a bit flag. Rename the variable to
reflect its nature and update the cast target since we're not supposed
to be comparing it to xfs_agblock_t now.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
We're supposed to initialize the list head of an object before adding it
to another list. Fix that, and stop using the kmem_{alloc,free} calls
from the Irix days.
Fixes: 174edb0e46 ("xfs: store in-progress CoW allocations in the refcount btree")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
As we've seen, refcount records use the upper bit of the rc_startblock
field to ensure that all the refcount records are at the right side of
the refcount btree. This works because an AG is never allowed to have
more than (1U << 31) blocks in it. If we ever encounter a filesystem
claiming to have that many blocks, we absolutely do not want reflink
touching it at all.
However, this test at the start of xfs_refcount_recover_cow_leftovers is
slightly incorrect -- it /should/ be checking that agblocks isn't larger
than the XFS_MAX_CRC_AG_BLOCKS constant, and it should check that the
constant is never large enough to conflict with that CoW flag.
Note that the V5 superblock verifier has not historically rejected
filesystems where agblocks >= XFS_MAX_CRC_AG_BLOCKS, which is why this
ended up in the COW recovery routine.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Now that we've separated the startblock and CoW/shared extent domain in
the incore refcount record structure, check the domain whenever we
retrieve a record to ensure that it's still in the domain that we want.
Depending on the circumstances, a change in domain either means we're
done processing or that we've found a corruption and need to fail out.
The refcount check in xchk_xref_is_cow_staging is redundant since
_get_rec has done that for a long time now, so we can get rid of it.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Now that we have an explicit enum for shared and CoW staging extents, we
can get rid of the old FIND_RCEXT flags. Omit a couple of conversions
that disappear in the next patches.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Create a helper function to ensure that CoW staging extent records have
a single refcount and that shared extent records have more than 1
refcount. We'll put this to more use in the next patch.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Now that we've broken out the startblock and shared/cow domain in the
incore refcount extent record structure, update the tracepoints to
report the domain.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Just prior to committing the reflink code into upstream, the xfs
maintainer at the time requested that I find a way to shard the refcount
records into two domains -- one for records tracking shared extents, and
a second for tracking CoW staging extents. The idea here was to
minimize mount time CoW reclamation by pushing all the CoW records to
the right edge of the keyspace, and it was accomplished by setting the
upper bit in rc_startblock. We don't allow AGs to have more than 2^31
blocks, so the bit was free.
Unfortunately, this was a very late addition to the codebase, so most of
the refcount record processing code still treats rc_startblock as a u32
and pays no attention to whether or not the upper bit (the cow flag) is
set. This is a weakness is theoretically exploitable, since we're not
fully validating the incoming metadata records.
Fuzzing demonstrates practical exploits of this weakness. If the cow
flag of a node block key record is corrupted, a lookup operation can go
to the wrong record block and start returning records from the wrong
cow/shared domain. This causes the math to go all wrong (since cow
domain is still implicit in the upper bit of rc_startblock) and we can
crash the kernel by tricking xfs into jumping into a nonexistent AG and
tripping over xfs_perag_get(mp, <nonexistent AG>) returning NULL.
To fix this, start tracking the domain as an explicit part of struct
xfs_refcount_irec, adjust all refcount functions to check the domain
of a returned record, and alter the function definitions to accept them
where necessary.
Found by fuzzing keys[2].cowflag = add in xfs/464.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Consolidate the open-coded xfs_refcount_irec fields into an actual
struct and use the existing _btrec_to_irec to decode the ondisk record.
This will reduce code churn in the next patch.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Structure definitions for incore objects do not belong in the ondisk
format header. Move them to the incore types header where they belong.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
If we're in the middle of a deferred refcount operation and decide to
roll the transaction to avoid overflowing the transaction space, we need
to check the new agbno/aglen parameters that we're about to record in
the new intent. Specifically, we need to check that the new extent is
completely within the filesystem, and that continuation does not put us
into a different AG.
If the keys of a node block are wrong, the lookup to resume an
xfs_refcount_adjust_extents operation can put us into the wrong record
block. If this happens, we might not find that we run out of aglen at
an exact record boundary, which will cause the loop control to do the
wrong thing.
The previous patch should take care of that problem, but let's add this
extra sanity check to stop corruption problems sooner than later.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Create a predicate function to verify that a given agbno/blockcount pair
fit entirely within a single allocation group and don't suffer
mathematical overflows. Refactor the existng open-coded logic; we're
going to add more calls to this function in the next patch.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Prior to calling xfs_refcount_adjust_extents, we trimmed agbno/aglen
such that the end of the range would not be in the middle of a refcount
record. If this is no longer the case, something is seriously wrong
with the btree. Bail out with a corruption error.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
If log recovery decides that an intent item is corrupt and wants to
abort the mount, capture a hexdump of the corrupt log item in the kernel
log for further analysis. Some of the log item code already did this,
so we're fixing the rest to do it consistently.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
If log recovery picks up intent-done log items that are not of the
correct size it needs to abort recovery and fail the mount. Debug
assertions are not good enough.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Refactor all the open-coded sizeof logic for EFI/EFD log item and log
format structures into common helper functions whose names reflect the
struct names.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Starting in 6.1, CONFIG_FORTIFY_SOURCE checks the length parameter of
memcpy. Since we're already fixing problems with BUI item copying, we
should fix it everything else.
An extra difficulty here is that the ef[id]_extents arrays are declared
as single-element arrays. This is not the convention for flex arrays in
the modern kernel, and it causes all manner of problems with static
checking tools, since they often cannot tell the difference between a
single element array and a flex array.
So for starters, change those array[1] declarations to array[]
declarations to signal that they are proper flex arrays and adjust all
the "size-1" expressions to fit the new declaration style.
Next, refactor the xfs_efi_copy_format function to handle the copying of
the head and the flex array members separately. While we're at it, fix
a minor validation deficiency in the recovery function.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Starting in 6.1, CONFIG_FORTIFY_SOURCE checks the length parameter of
memcpy. Since we're already fixing problems with BUI item copying, we
should fix it everything else.
Refactor the xfs_rui_copy_format function to handle the copying of the
head and the flex array members separately. While we're at it, fix a
minor validation deficiency in the recovery function.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Starting in 6.1, CONFIG_FORTIFY_SOURCE checks the length parameter of
memcpy. Since we're already fixing problems with BUI item copying, we
should fix it everything else.
Refactor the xfs_cui_copy_format function to handle the copying of the
head and the flex array members separately. While we're at it, fix a
minor validation deficiency in the recovery function.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Starting in 6.1, CONFIG_FORTIFY_SOURCE checks the length parameter of
memcpy. Unfortunately, it doesn't handle flex arrays correctly:
------------[ cut here ]------------
memcpy: detected field-spanning write (size 48) of single field "dst_bui_fmt" at fs/xfs/xfs_bmap_item.c:628 (size 16)
Fix this by refactoring the xfs_bui_copy_format function to handle the
copying of the head and the flex array members separately. While we're
at it, fix a minor validation deficiency in the recovery function.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Before we start fixing all the complaints about memcpy'ing log items
around, let's fix some inadequate validation in the xattr log item
recovery code and get rid of the (now trivial) copy_format function.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
The kernel robot complained about this:
>> fs/xfs/xfs_file.c:1266:31: sparse: sparse: incorrect type in return expression (different base types) @@ expected int @@ got restricted vm_fault_t @@
fs/xfs/xfs_file.c:1266:31: sparse: expected int
fs/xfs/xfs_file.c:1266:31: sparse: got restricted vm_fault_t
fs/xfs/xfs_file.c:1314:21: sparse: sparse: incorrect type in assignment (different base types) @@ expected restricted vm_fault_t [usertype] ret @@ got int @@
fs/xfs/xfs_file.c:1314:21: sparse: expected restricted vm_fault_t [usertype] ret
fs/xfs/xfs_file.c:1314:21: sparse: got int
Fix the incorrect return type for these two functions.
While we're at it, make the !fsdax version return VM_FAULT_SIGBUS
because a zero return value will cause some callers to try to lock
vmf->page, which we never set here.
Fixes: ea6c49b784 ("xfs: support CoW in fsdax mode")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
xfs_rename can update up to 5 inodes: src_dp, target_dp, src_ip, target_ip
and wip. So we need to increase the inode reservation to match.
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
kmemleak reported a sequence of memory leaks, and one of them indicated we
failed to free a pointer:
comm "mount", pid 19610, jiffies 4297086464 (age 60.635s)
hex dump (first 8 bytes):
73 64 61 00 81 88 ff ff sda.....
backtrace:
[<00000000d77f3e04>] kstrdup_const+0x46/0x70
[<00000000e51fa804>] kobject_set_name_vargs+0x2f/0xb0
[<00000000247cd595>] kobject_init_and_add+0xb0/0x120
[<00000000f9139aaf>] xfs_mountfs+0x367/0xfc0
[<00000000250d3caf>] xfs_fs_fill_super+0xa16/0xdc0
[<000000008d873d38>] get_tree_bdev+0x256/0x390
[<000000004881f3fa>] vfs_get_tree+0x41/0xf0
[<000000008291ab52>] path_mount+0x9b3/0xdd0
[<0000000022ba8f2d>] __x64_sys_mount+0x190/0x1d0
As mentioned in kobject_init_and_add() comment, if this function
returns an error, kobject_put() must be called to properly clean up
the memory associated with the object. Apparently, xfs_sysfs_init()
does not follow such a requirement. When kobject_init_and_add()
returns an error, the space of kobj->kobject.name alloced by
kstrdup_const() is unfree, which will cause the above stack.
Fix it by adding kobject_put() when kobject_init_and_add returns an
error.
Fixes: a31b1d3d89 ("xfs: add xfs_mount sysfs kobject")
Signed-off-by: Li Zetao <lizetao1@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
The assignment to pointer lip is not really required, the pointer lip
is redundant and can be removed.
Cleans up clang-scan warning:
warning: Although the value stored to 'lip' is used in the enclosing
expression, the value is never actually read from 'lip'
[deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
The current way of setting and getting posix acls through the generic
xattr interface is error prone and type unsafe. The vfs needs to
interpret and fixup posix acls before storing or reporting it to
userspace. Various hacks exist to make this work. The code is hard to
understand and difficult to maintain in it's current form. Instead of
making this work by hacking posix acls through xattr handlers we are
building a dedicated posix acl api around the get and set inode
operations. This removes a lot of hackiness and makes the codepaths
easier to maintain. A lot of background can be found in [1].
The current inode operation for getting posix acls takes an inode
argument but various filesystems (e.g., 9p, cifs, overlayfs) need access
to the dentry. In contrast to the ->set_acl() inode operation we cannot
simply extend ->get_acl() to take a dentry argument. The ->get_acl()
inode operation is called from:
acl_permission_check()
-> check_acl()
-> get_acl()
which is part of generic_permission() which in turn is part of
inode_permission(). Both generic_permission() and inode_permission() are
called in the ->permission() handler of various filesystems (e.g.,
overlayfs). So simply passing a dentry argument to ->get_acl() would
amount to also having to pass a dentry argument to ->permission(). We
should avoid this unnecessary change.
So instead of extending the existing inode operation rename it from
->get_acl() to ->get_inode_acl() and add a ->get_acl() method later that
passes a dentry argument and which filesystems that need access to the
dentry can implement instead of ->get_inode_acl(). Filesystems like cifs
which allow setting and getting posix acls but not using them for
permission checking during lookup can simply not implement
->get_inode_acl().
This is intended to be a non-functional change.
Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1]
Suggested-by/Inspired-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
The current way of setting and getting posix acls through the generic
xattr interface is error prone and type unsafe. The vfs needs to
interpret and fixup posix acls before storing or reporting it to
userspace. Various hacks exist to make this work. The code is hard to
understand and difficult to maintain in it's current form. Instead of
making this work by hacking posix acls through xattr handlers we are
building a dedicated posix acl api around the get and set inode
operations. This removes a lot of hackiness and makes the codepaths
easier to maintain. A lot of background can be found in [1].
Since some filesystem rely on the dentry being available to them when
setting posix acls (e.g., 9p and cifs) they cannot rely on set acl inode
operation. But since ->set_acl() is required in order to use the generic
posix acl xattr handlers filesystems that do not implement this inode
operation cannot use the handler and need to implement their own
dedicated posix acl handlers.
Update the ->set_acl() inode method to take a dentry argument. This
allows all filesystems to rely on ->set_acl().
As far as I can tell all codepaths can be switched to rely on the dentry
instead of just the inode. Note that the original motivation for passing
the dentry separate from the inode instead of just the dentry in the
xattr handlers was because of security modules that call
security_d_instantiate(). This hook is called during
d_instantiate_new(), d_add(), __d_instantiate_anon(), and
d_splice_alias() to initialize the inode's security context and possibly
to set security.* xattrs. Since this only affects security.* xattrs this
is completely irrelevant for posix acls.
Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1]
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
KASAN reported a UAF bug when I was running xfs/235:
BUG: KASAN: use-after-free in xlog_recover_process_intents+0xa77/0xae0 [xfs]
Read of size 8 at addr ffff88804391b360 by task mount/5680
CPU: 2 PID: 5680 Comm: mount Not tainted 6.0.0-xfsx #6.0.0 77e7b52a4943a975441e5ac90a5ad7748b7867f6
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x34/0x44
print_report.cold+0x2cc/0x682
kasan_report+0xa3/0x120
xlog_recover_process_intents+0xa77/0xae0 [xfs fb841c7180aad3f8359438576e27867f5795667e]
xlog_recover_finish+0x7d/0x970 [xfs fb841c7180aad3f8359438576e27867f5795667e]
xfs_log_mount_finish+0x2d7/0x5d0 [xfs fb841c7180aad3f8359438576e27867f5795667e]
xfs_mountfs+0x11d4/0x1d10 [xfs fb841c7180aad3f8359438576e27867f5795667e]
xfs_fs_fill_super+0x13d5/0x1a80 [xfs fb841c7180aad3f8359438576e27867f5795667e]
get_tree_bdev+0x3da/0x6e0
vfs_get_tree+0x7d/0x240
path_mount+0xdd3/0x17d0
__x64_sys_mount+0x1fa/0x270
do_syscall_64+0x2b/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7ff5bc069eae
Code: 48 8b 0d 85 1f 0f 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 52 1f 0f 00 f7 d8 64 89 01 48
RSP: 002b:00007ffe433fd448 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff5bc069eae
RDX: 00005575d7213290 RSI: 00005575d72132d0 RDI: 00005575d72132b0
RBP: 00005575d7212fd0 R08: 00005575d7213230 R09: 00005575d7213fe0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00005575d7213290 R14: 00005575d72132b0 R15: 00005575d7212fd0
</TASK>
Allocated by task 5680:
kasan_save_stack+0x1e/0x40
__kasan_slab_alloc+0x66/0x80
kmem_cache_alloc+0x152/0x320
xfs_rui_init+0x17a/0x1b0 [xfs]
xlog_recover_rui_commit_pass2+0xb9/0x2e0 [xfs]
xlog_recover_items_pass2+0xe9/0x220 [xfs]
xlog_recover_commit_trans+0x673/0x900 [xfs]
xlog_recovery_process_trans+0xbe/0x130 [xfs]
xlog_recover_process_data+0x103/0x2a0 [xfs]
xlog_do_recovery_pass+0x548/0xc60 [xfs]
xlog_do_log_recovery+0x62/0xc0 [xfs]
xlog_do_recover+0x73/0x480 [xfs]
xlog_recover+0x229/0x460 [xfs]
xfs_log_mount+0x284/0x640 [xfs]
xfs_mountfs+0xf8b/0x1d10 [xfs]
xfs_fs_fill_super+0x13d5/0x1a80 [xfs]
get_tree_bdev+0x3da/0x6e0
vfs_get_tree+0x7d/0x240
path_mount+0xdd3/0x17d0
__x64_sys_mount+0x1fa/0x270
do_syscall_64+0x2b/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
Freed by task 5680:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
kasan_set_free_info+0x20/0x30
____kasan_slab_free+0x144/0x1b0
slab_free_freelist_hook+0xab/0x180
kmem_cache_free+0x1f1/0x410
xfs_rud_item_release+0x33/0x80 [xfs]
xfs_trans_free_items+0xc3/0x220 [xfs]
xfs_trans_cancel+0x1fa/0x590 [xfs]
xfs_rui_item_recover+0x913/0xd60 [xfs]
xlog_recover_process_intents+0x24e/0xae0 [xfs]
xlog_recover_finish+0x7d/0x970 [xfs]
xfs_log_mount_finish+0x2d7/0x5d0 [xfs]
xfs_mountfs+0x11d4/0x1d10 [xfs]
xfs_fs_fill_super+0x13d5/0x1a80 [xfs]
get_tree_bdev+0x3da/0x6e0
vfs_get_tree+0x7d/0x240
path_mount+0xdd3/0x17d0
__x64_sys_mount+0x1fa/0x270
do_syscall_64+0x2b/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
The buggy address belongs to the object at ffff88804391b300
which belongs to the cache xfs_rui_item of size 688
The buggy address is located 96 bytes inside of
688-byte region [ffff88804391b300, ffff88804391b5b0)
The buggy address belongs to the physical page:
page:ffffea00010e4600 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888043919320 pfn:0x43918
head:ffffea00010e4600 order:2 compound_mapcount:0 compound_pincount:0
flags: 0x4fff80000010200(slab|head|node=1|zone=1|lastcpupid=0xfff)
raw: 04fff80000010200 0000000000000000 dead000000000122 ffff88807f0eadc0
raw: ffff888043919320 0000000080140010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88804391b200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88804391b280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88804391b300: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88804391b380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88804391b400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
The test fuzzes an rmap btree block and starts writer threads to induce
a filesystem shutdown on the corrupt block. When the filesystem is
remounted, recovery will try to replay the committed rmap intent item,
but the corruption problem causes the recovery transaction to fail.
Cancelling the transaction frees the RUD, which frees the RUI that we
recovered.
When we return to xlog_recover_process_intents, @lip is now a dangling
pointer, and we cannot use it to find the iop_recover method for the
tracepoint. Hence we must store the item ops before calling
->iop_recover if we want to give it to the tracepoint so that the trace
data will tell us exactly which intent item failed.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
The prandom_u32() function has been a deprecated inline wrapper around
get_random_u32() for several releases now, and compiles down to the
exact same code. Replace the deprecated wrapper with a direct call to
the real function. The same also applies to get_random_int(), which is
just a wrapper around get_random_u32(). This was done as a basic find
and replace.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake
Acked-by: Chuck Lever <chuck.lever@oracle.com> # for nfsd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for thunderbolt
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Acked-by: Helge Deller <deller@gmx.de> # for parisc
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with this coccinelle script:
@basic@
expression E;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u64;
@@
(
- ((T)get_random_u32() % (E))
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ((E) - 1))
+ prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2)
|
- ((u64)(E) * get_random_u32() >> 32)
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ~PAGE_MASK)
+ prandom_u32_max(PAGE_SIZE)
)
@multi_line@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
identifier RAND;
expression E;
@@
- RAND = get_random_u32();
... when != RAND
- RAND %= (E);
+ RAND = prandom_u32_max(E);
// Find a potential literal
@literal_mask@
expression LITERAL;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
position p;
@@
((T)get_random_u32()@p & (LITERAL))
// Add one to the literal.
@script:python add_one@
literal << literal_mask.LITERAL;
RESULT;
@@
value = None
if literal.startswith('0x'):
value = int(literal, 16)
elif literal[0] in '123456789':
value = int(literal, 10)
if value is None:
print("I don't know how to handle %s" % (literal))
cocci.include_match(False)
elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1:
print("Skipping 0x%x for cleanup elsewhere" % (value))
cocci.include_match(False)
elif value & (value + 1) != 0:
print("Skipping 0x%x because it's not a power of two minus one" % (value))
cocci.include_match(False)
elif literal.startswith('0x'):
coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1))
else:
coccinelle.RESULT = cocci.make_expr("%d" % (value + 1))
// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
expression add_one.RESULT;
identifier FUNC;
@@
- (FUNC()@p & (LITERAL))
+ prandom_u32_max(RESULT)
@collapse_ret@
type T;
identifier VAR;
expression E;
@@
{
- T VAR;
- VAR = (E);
- return VAR;
+ return E;
}
@drop_var@
type T;
identifier VAR;
@@
{
- T VAR;
... when != VAR
}
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This update contains:
- fixes for filesystem shutdown procedure during a DAX memory
failure notification
- bug fixes
- logic cleanups
- log message cleanups
- updates to use vfs{g,u}id_t helpers where appropriate
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Merge tag 'xfs-6.1-for-linus' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs updates from Dave Chinner:
"There are relatively few updates this cycle; half the cycle was eaten
by a grue, the other half was eaten by a tricky data corruption issue
that I still haven't entirely solved.
Hence there's no major changes in this cycle and it's largely just
minor cleanups and small bug fixes:
- fixes for filesystem shutdown procedure during a DAX memory failure
notification
- bug fixes
- logic cleanups
- log message cleanups
- updates to use vfs{g,u}id_t helpers where appropriate"
* tag 'xfs-6.1-for-linus' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: on memory failure, only shut down fs after scanning all mappings
xfs: rearrange the logic and remove the broken comment for xfs_dir2_isxx
xfs: trim the mapp array accordingly in xfs_da_grow_inode_int
xfs: do not need to check return value of xlog_kvmalloc()
xfs: port to vfs{g,u}id_t and associated helpers
xfs: remove xfs_setattr_time() declaration
xfs: Remove the unneeded result variable
xfs: missing space in xfs trace log
xfs: simplify if-else condition in xfs_reflink_trim_around_shared
xfs: simplify if-else condition in xfs_validate_new_dalign
xfs: replace unnecessary seq_printf with seq_puts
xfs: clean up "%Ld/%Lu" which doesn't meet C standard
xfs: remove redundant else for clean code
xfs: remove the redundant word in comment
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Merge tag 'pull-tmpfile' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs tmpfile updates from Al Viro:
"Miklos' ->tmpfile() signature change; pass an unopened struct file to
it, let it open the damn thing. Allows to add tmpfile support to FUSE"
* tag 'pull-tmpfile' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fuse: implement ->tmpfile()
vfs: open inside ->tmpfile()
vfs: move open right after ->tmpfile()
vfs: make vfs_tmpfile() static
ovl: use vfs_tmpfile_open() helper
cachefiles: use vfs_tmpfile_open() helper
cachefiles: only pass inode to *mark_inode_inuse() helpers
cachefiles: tmpfile error handling cleanup
hugetlbfs: cleanup mknod and tmpfile
vfs: add vfs_tmpfile_open() helper
- Debuggability:
- Change most occurances of BUG_ON() to WARN_ON_ONCE()
- Reorganize & fix TASK_ state comparisons, turn it into a bitmap
- Update/fix misc scheduler debugging facilities
- Load-balancing & regular scheduling:
- Improve the behavior of the scheduler in presence of lot of
SCHED_IDLE tasks - in particular they should not impact other
scheduling classes.
- Optimize task load tracking, cleanups & fixes
- Clean up & simplify misc load-balancing code
- Freezer:
- Rewrite the core freezer to behave better wrt thawing and be simpler
in general, by replacing PF_FROZEN with TASK_FROZEN & fixing/adjusting
all the fallout.
- Deadline scheduler:
- Fix the DL capacity-aware code
- Factor out dl_task_is_earliest_deadline() & replenish_dl_new_period()
- Relax/optimize locking in task_non_contending()
- Cleanups:
- Factor out the update_current_exec_runtime() helper
- Various cleanups, simplifications
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
"Debuggability:
- Change most occurances of BUG_ON() to WARN_ON_ONCE()
- Reorganize & fix TASK_ state comparisons, turn it into a bitmap
- Update/fix misc scheduler debugging facilities
Load-balancing & regular scheduling:
- Improve the behavior of the scheduler in presence of lot of
SCHED_IDLE tasks - in particular they should not impact other
scheduling classes.
- Optimize task load tracking, cleanups & fixes
- Clean up & simplify misc load-balancing code
Freezer:
- Rewrite the core freezer to behave better wrt thawing and be
simpler in general, by replacing PF_FROZEN with TASK_FROZEN &
fixing/adjusting all the fallout.
Deadline scheduler:
- Fix the DL capacity-aware code
- Factor out dl_task_is_earliest_deadline() &
replenish_dl_new_period()
- Relax/optimize locking in task_non_contending()
Cleanups:
- Factor out the update_current_exec_runtime() helper
- Various cleanups, simplifications"
* tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
sched: Fix more TASK_state comparisons
sched: Fix TASK_state comparisons
sched/fair: Move call to list_last_entry() in detach_tasks
sched/fair: Cleanup loop_max and loop_break
sched/fair: Make sure to try to detach at least one movable task
sched: Show PF_flag holes
freezer,sched: Rewrite core freezer logic
sched: Widen TAKS_state literals
sched/wait: Add wait_event_state()
sched/completion: Add wait_for_completion_state()
sched: Add TASK_ANY for wait_task_inactive()
sched: Change wait_task_inactive()s match_state
freezer,umh: Clean up freezer/initrd interaction
freezer: Have {,un}lock_system_sleep() save/restore flags
sched: Rename task_running() to task_on_cpu()
sched/fair: Cleanup for SIS_PROP
sched/fair: Default to false in test_idle_cores()
sched/fair: Remove useless check in select_idle_core()
sched/fair: Avoid double search on same cpu
sched/fair: Remove redundant check in select_idle_smt()
...
- submit_bh() can never return an error, so change it to return void,
and remove the unused checks from its callers
- fix I_DIRTY_TIME handling so it will be set even if the inode
already has I_DIRTY_INODE
Performance:
- Always enable i_version counter (as btrfs and xfs already do).
Remove some uneeded i_version bumps to avoid unnecessary nfs cache
invalidations.
- Wake up journal waters in FIFO order, to avoid some journal users
from not getting a journal handle for an unfairly long time.
- In ext4_write_begin() allocate any necessary buffer heads before
starting the journal handle.
- Don't try to prefetch the block allocation bitmaps for a read-only
file system.
Bug Fixes:
- Fix a number of fast commit bugs, including resources leaks and out
of bound references in various error handling paths and/or if the fast
commit log is corrupted.
- Avoid stopping the online resize early when expanding a file system
which is less than 16TiB to a size greater than 16TiB.
- Fix apparent metadata corruption caused by a race with a metadata
buffer head getting migrated while it was trying to be read.
- Mark the lazy initialization thread freezable to prevent suspend
failures.
- Other miscellaneous bug fixes.
Cleanups:
- Break up the incredibly long ext4_full_super() function by
refactoring to move code into more understandable, smaller
functions.
- Remove the deprecated (and ignored) noacl and nouser_attr mount
option.
- Factor out some common code in fast commit handling.
- Other miscellaneous cleanups.
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:
"The first two changes involve files outside of fs/ext4:
- submit_bh() can never return an error, so change it to return void,
and remove the unused checks from its callers
- fix I_DIRTY_TIME handling so it will be set even if the inode
already has I_DIRTY_INODE
Performance:
- Always enable i_version counter (as btrfs and xfs already do).
Remove some uneeded i_version bumps to avoid unnecessary nfs cache
invalidations
- Wake up journal waiters in FIFO order, to avoid some journal users
from not getting a journal handle for an unfairly long time
- In ext4_write_begin() allocate any necessary buffer heads before
starting the journal handle
- Don't try to prefetch the block allocation bitmaps for a read-only
file system
Bug Fixes:
- Fix a number of fast commit bugs, including resources leaks and out
of bound references in various error handling paths and/or if the
fast commit log is corrupted
- Avoid stopping the online resize early when expanding a file system
which is less than 16TiB to a size greater than 16TiB
- Fix apparent metadata corruption caused by a race with a metadata
buffer head getting migrated while it was trying to be read
- Mark the lazy initialization thread freezable to prevent suspend
failures
- Other miscellaneous bug fixes
Cleanups:
- Break up the incredibly long ext4_full_super() function by
refactoring to move code into more understandable, smaller
functions
- Remove the deprecated (and ignored) noacl and nouser_attr mount
option
- Factor out some common code in fast commit handling
- Other miscellaneous cleanups"
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (53 commits)
ext4: fix potential out of bound read in ext4_fc_replay_scan()
ext4: factor out ext4_fc_get_tl()
ext4: introduce EXT4_FC_TAG_BASE_LEN helper
ext4: factor out ext4_free_ext_path()
ext4: remove unnecessary drop path references in mext_check_coverage()
ext4: update 'state->fc_regions_size' after successful memory allocation
ext4: fix potential memory leak in ext4_fc_record_regions()
ext4: fix potential memory leak in ext4_fc_record_modified_inode()
ext4: remove redundant checking in ext4_ioctl_checkpoint
jbd2: add miss release buffer head in fc_do_one_pass()
ext4: move DIOREAD_NOLOCK setting to ext4_set_def_opts()
ext4: remove useless local variable 'blocksize'
ext4: unify the ext4 super block loading operation
ext4: factor out ext4_journal_data_mode_check()
ext4: factor out ext4_load_and_init_journal()
ext4: factor out ext4_group_desc_init() and ext4_group_desc_free()
ext4: factor out ext4_geometry_check()
ext4: factor out ext4_check_feature_compatibility()
ext4: factor out ext4_init_metadata_csum()
ext4: factor out ext4_encoding_init()
...
xfs_dax_failure_fn is used to scan the filesystem during a memory
failure event to look for memory mappings to revoke. Unfortunately,
if it encounters an rmap record for filesystem metadata, it will
shut down the filesystem and the scan immediately. This means that
we don't complete the mapping revocation scan and instead leave live
mappings to failed memory. Fix the function to defer the shutdown
until after we've finished culling mappings.
While we're at it, add the usual "xfs_" prefix to struct
failure_info, and actually initialize mf_flags.
Fixes: 6f643c57d5 ("xfs: implement ->notify_failure() for XFS")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
xfs_dir2_isleaf is used to see if the directory is a single-leaf
form directory instead, as commented right above the function.
Besides getting rid of the broken comment, we rearrange the logic by
converting everything over to standard formatting and conventions,
at the same time, to make it easier to understand and self documenting.
Signed-off-by: Shida Zhang <zhangshida@kylinos.cn>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Take a look at the for-loop in xfs_da_grow_inode_int:
======
for(){
nmap = min(XFS_BMAP_MAX_NMAP, count);
...
error = xfs_bmapi_write(...,&mapp[mapi], &nmap);//(..., $1, $2)
...
mapi += nmap;
}
=====
where $1 stands for the start address of the array,
while $2 is used to indicate the size of the array.
The array $1 will advance by $nmap in each iteration after
the allocation of extents.
But the size $2 still remains unchanged, which is determined by
min(XFS_BMAP_MAX_NMAP, count).
It seems that it has forgotten to trim the mapp array after each
iteration, so change it.
Signed-off-by: Shida Zhang <zhangshida@kylinos.cn>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Make statx() support reporting direct I/O (DIO) alignment information.
This provides a generic interface for userspace programs to determine
whether a file supports DIO, and if so with what alignment restrictions.
Specifically, STATX_DIOALIGN works on block devices, and on regular
files when their containing filesystem has implemented support.
An interface like this has been requested for years, since the
conditions for when DIO is supported in Linux have gotten increasingly
complex over time. Today, DIO support and alignment requirements can be
affected by various filesystem features such as multi-device support,
data journalling, inline data, encryption, verity, compression,
checkpoint disabling, log-structured mode, etc. Further complicating
things, Linux v6.0 relaxed the traditional rule of DIO needing to be
aligned to the block device's logical block size; now user buffers (but
not file offsets) only need to be aligned to the DMA alignment.
The approach of uplifting the XFS specific ioctl XFS_IOC_DIOINFO was
discarded in favor of creating a clean new interface with statx().
For more information, see the individual commits and the man page update
https://lore.kernel.org/r/20220722074229.148925-1-ebiggers@kernel.org.
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Merge tag 'statx-dioalign-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux
Pull STATX_DIOALIGN support from Eric Biggers:
"Make statx() support reporting direct I/O (DIO) alignment information.
This provides a generic interface for userspace programs to determine
whether a file supports DIO, and if so with what alignment
restrictions. Specifically, STATX_DIOALIGN works on block devices, and
on regular files when their containing filesystem has implemented
support.
An interface like this has been requested for years, since the
conditions for when DIO is supported in Linux have gotten increasingly
complex over time. Today, DIO support and alignment requirements can
be affected by various filesystem features such as multi-device
support, data journalling, inline data, encryption, verity,
compression, checkpoint disabling, log-structured mode, etc.
Further complicating things, Linux v6.0 relaxed the traditional rule
of DIO needing to be aligned to the block device's logical block size;
now user buffers (but not file offsets) only need to be aligned to the
DMA alignment.
The approach of uplifting the XFS specific ioctl XFS_IOC_DIOINFO was
discarded in favor of creating a clean new interface with statx().
For more information, see the individual commits and the man page
update[1]"
Link: https://lore.kernel.org/r/20220722074229.148925-1-ebiggers@kernel.org [1]
* tag 'statx-dioalign-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux:
xfs: support STATX_DIOALIGN
f2fs: support STATX_DIOALIGN
f2fs: simplify f2fs_force_buffered_io()
f2fs: move f2fs_force_buffered_io() into file.c
ext4: support STATX_DIOALIGN
fscrypt: change fscrypt_dio_supported() to prepare for STATX_DIOALIGN
vfs: support STATX_DIOALIGN on block devices
statx: add direct I/O alignment information
Currently the I_DIRTY_TIME will never get set if the inode already has
I_DIRTY_INODE with assumption that it supersedes I_DIRTY_TIME. That's
true, however ext4 will only update the on-disk inode in
->dirty_inode(), not on actual writeback. As a result if the inode
already has I_DIRTY_INODE state by the time we get to
__mark_inode_dirty() only with I_DIRTY_TIME, the time was already filled
into on-disk inode and will not get updated until the next I_DIRTY_INODE
update, which might never come if we crash or get a power failure.
The problem can be reproduced on ext4 by running xfstest generic/622
with -o iversion mount option.
Fix it by allowing I_DIRTY_TIME to be set even if the inode already has
I_DIRTY_INODE. Also make sure that the case is properly handled in
writeback_single_inode() as well. Additionally changes in
xfs_fs_dirty_inode() was made to accommodate for I_DIRTY_TIME in flag.
Thanks Jan Kara for suggestions on how to make this work properly.
Cc: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: stable@kernel.org
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220825100657.44217-1-lczerner@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This is in preparation for adding tmpfile support to fuse, which requires
that the tmpfile creation and opening are done as a single operation.
Replace the 'struct dentry *' argument of i_op->tmpfile with
'struct file *'.
Call finish_open_simple() as the last thing in ->tmpfile() instances (may
be omitted in the error case).
Change d_tmpfile() argument to 'struct file *' as well to make callers more
readable.
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
In xfs_attri_log_nameval_alloc(), xlog_kvmalloc() is called
to alloc memory, which will always return
successfully, so we donot need to check return value.
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
A while ago we introduced a dedicated vfs{g,u}id_t type in commit
1e5267cd08 ("mnt_idmapping: add vfs{g,u}id_t"). We already switched
over a good part of the VFS. Ultimately we will remove all legacy
idmapped mount helpers that operate only on k{g,u}id_t in favor of the
new type safe helpers that operate on vfs{g,u}id_t.
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
xfs_setattr_time() has been removed since
commit e014f37db1 ("xfs: use setattr_copy to set vfs inode
attributes"), so remove it.
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Return the value xfs_dir_cilookup_result() directly instead of storing it
in another redundant variable.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Add space between arguments would help someone
to locate the key words they want, so break
quoted strings at a space character.
Such as below:
[Before]
kworker/1:0-280 [001] ..... 600.782135: xfs_bunmap:
dev 7:0 ino 0x85 disize 0x0 fileoff 0x0 fsbcount 0x400000001fffffflags ATTRFORK ...
[After]
kworker/1:2-564 [001] ..... 23817.906160: xfs_bunmap:
dev 7:0 ino 0x85 disize 0x0 fileoff 0x0 fsbcount 0x400000001fffff flags ATTRFORK ...
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
"else" is not generally useful after a return,
so remove it for clean code.
There is no logical changes.
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
"else" is not generally useful after a return,
so remove them which makes if condition a bit
more clear.
There is no logical changes.
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Replace seq_printf with seq_puts when const string
in reference, which would avoid to deal with
unnecessary string format.
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
The "%Ld" specifier, which represents long long unsigned,
doesn't meet C language standard, and even more,
it makes people easily mistake with "%ld", which represent
long unsigned. So replace "%Ld" with "lld".
Do the same with "%Lu".
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
"else" is not generally useful after a return, so remove it for clean code.
There is no logical changes.
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Just remove the redundant word "being" in comment.
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Add support for STATX_DIOALIGN to xfs, so that direct I/O alignment
restrictions are exposed to userspace in a generic way.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20220827065851.135710-9-ebiggers@kernel.org
The SB_BORN flag is stored in the vfs superblock, not xfs_sb.
Link: https://lkml.kernel.org/r/166153428094.2758201.7936572520826540019.stgit@dwillia2-xfh.jf.intel.com
Fixes: 6f643c57d5 ("xfs: implement ->notify_failure() for XFS")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm, xfs, dax: Fixes for memory_failure() handling".
I failed to run the memory error injection section of the ndctl test suite
on linux-next prior to the merge window and as a result some bugs were
missed. While the new enabling targeted reflink enabled XFS filesystems
the bugs cropped up in the surrounding cases of DAX error injection on
ext4-fsdax and device-dax.
One new assumption / clarification in this set is the notion that if a
filesystem's ->notify_failure() handler returns -EOPNOTSUPP, then it must
be the case that the fsdax usage of page->index and page->mapping are
valid. I am fairly certain this is true for xfs_dax_notify_failure(), but
would appreciate another set of eyes.
This patch (of 4):
XFS always registers dax_holder_operations regardless of whether the
filesystem is capable of handling the notifications. The expectation is
that if the notify_failure handler cannot run then there are no scenarios
where it needs to run. In other words the expected semantic is that
page->index and page->mapping are valid for memory_failure() when the
conditions that cause -EOPNOTSUPP in xfs_dax_notify_failure() are present.
A fallback to the generic memory_failure() path is expected so do not warn
when that happens.
Link: https://lkml.kernel.org/r/166153426798.2758201.15108211981034512993.stgit@dwillia2-xfh.jf.intel.com
Link: https://lkml.kernel.org/r/166153427440.2758201.6709480562966161512.stgit@dwillia2-xfh.jf.intel.com
Fixes: 6f643c57d5 ("xfs: implement ->notify_failure() for XFS")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Rewrite the core freezer to behave better wrt thawing and be simpler
in general.
By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is
ensured frozen tasks stay frozen until thawed and don't randomly wake
up early, as is currently possible.
As such, it does away with PF_FROZEN and PF_FREEZER_SKIP, freeing up
two PF_flags (yay!).
Specifically; the current scheme works a little like:
freezer_do_not_count();
schedule();
freezer_count();
And either the task is blocked, or it lands in try_to_freezer()
through freezer_count(). Now, when it is blocked, the freezer
considers it frozen and continues.
However, on thawing, once pm_freezing is cleared, freezer_count()
stops working, and any random/spurious wakeup will let a task run
before its time.
That is, thawing tries to thaw things in explicit order; kernel
threads and workqueues before doing bringing SMP back before userspace
etc.. However due to the above mentioned races it is entirely possible
for userspace tasks to thaw (by accident) before SMP is back.
This can be a fatal problem in asymmetric ISA architectures (eg ARMv9)
where the userspace task requires a special CPU to run.
As said; replace this with a special task state TASK_FROZEN and add
the following state transitions:
TASK_FREEZABLE -> TASK_FROZEN
__TASK_STOPPED -> TASK_FROZEN
__TASK_TRACED -> TASK_FROZEN
The new TASK_FREEZABLE can be set on any state part of TASK_NORMAL
(IOW. TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE) -- any such state
is already required to deal with spurious wakeups and the freezer
causes one such when thawing the task (since the original state is
lost).
The special __TASK_{STOPPED,TRACED} states *can* be restored since
their canonical state is in ->jobctl.
With this, frozen tasks need an explicit TASK_FROZEN wakeup and are
free of undue (early / spurious) wakeups.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220822114649.055452969@infradead.org
filldir_t instances (directory iterators callbacks) used to return 0 for
"OK, keep going" or -E... for "stop". Note that it's *NOT* how the
error values are reported - the rules for those are callback-dependent
and ->iterate{,_shared}() instances only care about zero vs. non-zero
(look at emit_dir() and friends).
So let's just return bool ("should we keep going?") - it's less confusing
that way. The choice between "true means keep going" and "true means
stop" is bikesheddable; we have two groups of callbacks -
do something for everything in directory, until we run into problem
and
find an entry in directory and do something to it.
The former tended to use 0/-E... conventions - -E<something> on failure.
The latter tended to use 0/1, 1 being "stop, we are done".
The callers treated anything non-zero as "stop", ignoring which
non-zero value did they get.
"true means stop" would be more natural for the second group; "true
means keep going" - for the first one. I tried both variants and
the things like
if allocation failed
something = -ENOMEM;
return true;
just looked unnatural and asking for trouble.
[folded suggestion from Matthew Wilcox <willy@infradead.org>]
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
- Return error codes from block device flushes to userspace.
- Fix a deadlock between reclaim and mount time quotacheck.
- Fix an unnecessary ENOSPC return when doing COW on a filesystem with
severe free space fragmentation.
- Fix a miscalculation in the transaction reservation computations for
file removal operations.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Merge tag 'xfs-5.20-merge-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull more xfs updates from Darrick Wong:
"There's not a lot this time around, just the usual bug fixes and
corrections for missing error returns.
- Return error codes from block device flushes to userspace
- Fix a deadlock between reclaim and mount time quotacheck
- Fix an unnecessary ENOSPC return when doing COW on a filesystem
with severe free space fragmentation
- Fix a miscalculation in the transaction reservation computations
for file removal operations"
* tag 'xfs-5.20-merge-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: fix inode reservation space for removing transaction
xfs: Fix false ENOSPC when performing direct write on a delalloc extent in cow fork
xfs: fix intermittent hang during quotacheck
xfs: check return codes when flushing block devices
In 'fs/xfs/libxfs/xfs_trans_resv.c', the comment for transaction of removing a
directory entry writes:
/* fs/xfs/libxfs/xfs_trans_resv.c begin */
/*
* For removing a directory entry we can modify:
* the parent directory inode: inode size
* the removed inode: inode size
...
xfs_calc_remove_reservation(
struct xfs_mount *mp)
{
return XFS_DQUOT_LOGRES(mp) +
xfs_calc_iunlink_add_reservation(mp) +
max((xfs_calc_inode_res(mp, 1) +
...
/* fs/xfs/libxfs/xfs_trans_resv.c end */
There has 2 inode size of space to be reserverd, but the actual code
for inode reservation space writes.
There only count for 1 inode size to be reserved in
'xfs_calc_inode_res(mp, 1)', rather than 2.
Signed-off-by: hexiaole <hexiaole@kylinos.cn>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
[djwong: remove redundant code citations]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
On a higly fragmented filesystem a Direct IO write can fail with -ENOSPC error
even though the filesystem has sufficient number of free blocks.
This occurs if the file offset range on which the write operation is being
performed has a delalloc extent in the cow fork and this delalloc extent
begins much before the Direct IO range.
In such a scenario, xfs_reflink_allocate_cow() invokes xfs_bmapi_write() to
allocate the blocks mapped by the delalloc extent. The extent thus allocated
may not cover the beginning of file offset range on which the Direct IO write
was issued. Hence xfs_reflink_allocate_cow() ends up returning -ENOSPC.
The following script reliably recreates the bug described above.
#!/usr/bin/bash
device=/dev/loop0
shortdev=$(basename $device)
mntpnt=/mnt/
file1=${mntpnt}/file1
file2=${mntpnt}/file2
fragmentedfile=${mntpnt}/fragmentedfile
punchprog=/root/repos/xfstests-dev/src/punch-alternating
errortag=/sys/fs/xfs/${shortdev}/errortag/bmap_alloc_minlen_extent
umount $device > /dev/null 2>&1
echo "Create FS"
mkfs.xfs -f -m reflink=1 $device > /dev/null 2>&1
if [[ $? != 0 ]]; then
echo "mkfs failed."
exit 1
fi
echo "Mount FS"
mount $device $mntpnt > /dev/null 2>&1
if [[ $? != 0 ]]; then
echo "mount failed."
exit 1
fi
echo "Create source file"
xfs_io -f -c "pwrite 0 32M" $file1 > /dev/null 2>&1
sync
echo "Create Reflinked file"
xfs_io -f -c "reflink $file1" $file2 &>/dev/null
echo "Set cowextsize"
xfs_io -c "cowextsize 16M" $file1 > /dev/null 2>&1
echo "Fragment FS"
xfs_io -f -c "pwrite 0 64M" $fragmentedfile > /dev/null 2>&1
sync
$punchprog $fragmentedfile
echo "Allocate block sized extent from now onwards"
echo -n 1 > $errortag
echo "Create 16MiB delalloc extent in CoW fork"
xfs_io -c "pwrite 0 4k" $file1 > /dev/null 2>&1
sync
echo "Direct I/O write at offset 12k"
xfs_io -d -c "pwrite 12k 8k" $file1
This commit fixes the bug by invoking xfs_bmapi_write() in a loop until disk
blocks are allocated for atleast the starting file offset of the Direct IO
write range.
Fixes: 3c68d44a2b ("xfs: allocate direct I/O COW blocks in iomap_begin")
Reported-and-Root-caused-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
[djwong: slight editing to make the locking less grody, and fix some style things]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Every now and then, I see the following hang during mount time
quotacheck when running fstests. Turning on KASAN seems to make it
happen somewhat more frequently. I've edited the backtrace for brevity.
XFS (sdd): Quotacheck needed: Please wait.
XFS: Assertion failed: bp->b_flags & _XBF_DELWRI_Q, file: fs/xfs/xfs_buf.c, line: 2411
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1831409 at fs/xfs/xfs_message.c:104 assfail+0x46/0x4a [xfs]
CPU: 0 PID: 1831409 Comm: mount Tainted: G W 5.19.0-rc6-xfsx #rc6 09911566947b9f737b036b4af85e399e4b9aef64
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
RIP: 0010:assfail+0x46/0x4a [xfs]
Code: a0 8f 41 a0 e8 45 fe ff ff 8a 1d 2c 36 10 00 80 fb 01 76 0f 0f b6 f3 48 c7 c7 c0 f0 4f a0 e8 10 f0 02 e1 80 e3 01 74 02 0f 0b <0f> 0b 5b c3 48 8d 45 10 48 89 e2 4c 89 e6 48 89 1c 24 48 89 44 24
RSP: 0018:ffffc900078c7b30 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880099ac000 RCX: 000000007fffffff
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffa0418fa0
RBP: ffff8880197bc1c0 R08: 0000000000000000 R09: 000000000000000a
R10: 000000000000000a R11: f000000000000000 R12: ffffc900078c7d20
R13: 00000000fffffff5 R14: ffffc900078c7d20 R15: 0000000000000000
FS: 00007f0449903800(0000) GS:ffff88803ec00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005610ada631f0 CR3: 0000000014dd8002 CR4: 00000000001706f0
Call Trace:
<TASK>
xfs_buf_delwri_pushbuf+0x150/0x160 [xfs 4561f5b32c9bfb874ec98d58d0719464e1f87368]
xfs_qm_flush_one+0xd6/0x130 [xfs 4561f5b32c9bfb874ec98d58d0719464e1f87368]
xfs_qm_dquot_walk.isra.0+0x109/0x1e0 [xfs 4561f5b32c9bfb874ec98d58d0719464e1f87368]
xfs_qm_quotacheck+0x319/0x490 [xfs 4561f5b32c9bfb874ec98d58d0719464e1f87368]
xfs_qm_mount_quotas+0x65/0x2c0 [xfs 4561f5b32c9bfb874ec98d58d0719464e1f87368]
xfs_mountfs+0x6b5/0xab0 [xfs 4561f5b32c9bfb874ec98d58d0719464e1f87368]
xfs_fs_fill_super+0x781/0x990 [xfs 4561f5b32c9bfb874ec98d58d0719464e1f87368]
get_tree_bdev+0x175/0x280
vfs_get_tree+0x1a/0x80
path_mount+0x6f5/0xaa0
__x64_sys_mount+0x103/0x140
do_syscall_64+0x2b/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
I /think/ this can happen if xfs_qm_flush_one is racing with
xfs_qm_dquot_isolate (i.e. dquot reclaim) when the second function has
taken the dquot flush lock but xfs_qm_dqflush hasn't yet locked the
dquot buffer, let alone queued it to the delwri list. In this case,
flush_one will fail to get the dquot flush lock, but it can lock the
incore buffer, but xfs_buf_delwri_pushbuf will then trip over this
ASSERT, which checks that the buffer isn't on a delwri list. The hang
results because the _delwri_submit_buffers ignores non DELWRI_Q buffers,
which means that xfs_buf_iowait waits forever for an IO that has not yet
been scheduled.
AFAICT, a reasonable solution here is to detect a dquot buffer that is
not on a DELWRI list, drop it, and return -EAGAIN to try the flush
again. It's not /that/ big of a deal if quotacheck writes the dquot
buffer repeatedly before we even set QUOTA_CHKD.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
If a blkdev_issue_flush fails, fsync needs to report that to upper
levels. Modify xfs_file_fsync to capture the errors, while trying to
flush as much data and log updates to disk as possible.
If log writes cannot flush the data device, we need to shut down the log
immediately because we've violated a log invariant. Modify this code to
check the return value of blkdev_issue_flush as well.
This behavior seems to go back to about 2.6.15 or so, which makes this
fixes tag a bit misleading.
Link: https://elixir.bootlin.com/linux/v2.6.15/source/fs/xfs/xfs_vnodeops.c#L1187
Fixes: b5071ada51 ("xfs: remove xfs_blkdev_issue_flush")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Lin, Yang Shi, Anshuman Khandual and Mike Rapoport
- Some kmemleak fixes from Patrick Wang and Waiman Long
- DAMON updates from SeongJae Park
- memcg debug/visibility work from Roman Gushchin
- vmalloc speedup from Uladzislau Rezki
- more folio conversion work from Matthew Wilcox
- enhancements for coherent device memory mapping from Alex Sierra
- addition of shared pages tracking and CoW support for fsdax, from
Shiyang Ruan
- hugetlb optimizations from Mike Kravetz
- Mel Gorman has contributed some pagealloc changes to improve latency
and realtime behaviour.
- mprotect soft-dirty checking has been improved by Peter Xu
- Many other singleton patches all over the place
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Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"Most of the MM queue. A few things are still pending.
Liam's maple tree rework didn't make it. This has resulted in a few
other minor patch series being held over for next time.
Multi-gen LRU still isn't merged as we were waiting for mapletree to
stabilize. The current plan is to merge MGLRU into -mm soon and to
later reintroduce mapletree, with a view to hopefully getting both
into 6.1-rc1.
Summary:
- The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
Lin, Yang Shi, Anshuman Khandual and Mike Rapoport
- Some kmemleak fixes from Patrick Wang and Waiman Long
- DAMON updates from SeongJae Park
- memcg debug/visibility work from Roman Gushchin
- vmalloc speedup from Uladzislau Rezki
- more folio conversion work from Matthew Wilcox
- enhancements for coherent device memory mapping from Alex Sierra
- addition of shared pages tracking and CoW support for fsdax, from
Shiyang Ruan
- hugetlb optimizations from Mike Kravetz
- Mel Gorman has contributed some pagealloc changes to improve
latency and realtime behaviour.
- mprotect soft-dirty checking has been improved by Peter Xu
- Many other singleton patches all over the place"
[ XFS merge from hell as per Darrick Wong in
https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ]
* tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits)
tools/testing/selftests/vm/hmm-tests.c: fix build
mm: Kconfig: fix typo
mm: memory-failure: convert to pr_fmt()
mm: use is_zone_movable_page() helper
hugetlbfs: fix inaccurate comment in hugetlbfs_statfs()
hugetlbfs: cleanup some comments in inode.c
hugetlbfs: remove unneeded header file
hugetlbfs: remove unneeded hugetlbfs_ops forward declaration
hugetlbfs: use helper macro SZ_1{K,M}
mm: cleanup is_highmem()
mm/hmm: add a test for cross device private faults
selftests: add soft-dirty into run_vmtests.sh
selftests: soft-dirty: add test for mprotect
mm/mprotect: fix soft-dirty check in can_change_pte_writable()
mm: memcontrol: fix potential oom_lock recursion deadlock
mm/gup.c: fix formatting in check_and_migrate_movable_page()
xfs: fail dax mount if reflink is enabled on a partition
mm/memcontrol.c: remove the redundant updating of stats_flush_threshold
userfaultfd: don't fail on unrecognized features
hugetlb_cgroup: fix wrong hugetlb cgroup numa stat
...
- Improve scalability of the XFS log by removing spinlocks and global
synchronization points.
- Add security labels to whiteout inodes to match the other filesystems.
- Clean up per-ag pointer passing to simplify call sites.
- Reduce verifier overhead by precalculating more AG geometry.
- Implement fast-path lockless lookups in the buffer cache to reduce
spinlock hammering.
- Make attr forks a permanent part of the inode structure to fix a UAF
bug and because most files these days tend to have security labels and
soon will have parent pointers too.
- Clean up XFS_IFORK_Q usage and give it a better name.
- Fix more UAF bugs in the xattr code.
- SOB my tags.
- Fix some typos in the timestamp range documentation.
- Fix a few more memory leaks.
- Code cleanups and typo fixes.
- Fix an unlocked inode fork pointer access in getbmap.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Merge tag 'xfs-5.20-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs updates from Darrick Wong:
"The biggest changes for this release are the log scalability
improvements, lockless lookups for the buffer cache, and making the
attr fork a permanent part of the incore inode in preparation for
directory parent pointers.
There's also a bunch of bug fixes that have accumulated since -rc5. I
might send you a second pull request with some more bug fixes that I'm
still working on.
Once the merge window ends, I will hand maintainership back to Dave
Chinner until the 6.1-rc1 release so that I can conduct the design
review for the online fsck feature, and try to get it merged.
Summary:
- Improve scalability of the XFS log by removing spinlocks and global
synchronization points.
- Add security labels to whiteout inodes to match the other
filesystems.
- Clean up per-ag pointer passing to simplify call sites.
- Reduce verifier overhead by precalculating more AG geometry.
- Implement fast-path lockless lookups in the buffer cache to reduce
spinlock hammering.
- Make attr forks a permanent part of the inode structure to fix a
UAF bug and because most files these days tend to have security
labels and soon will have parent pointers too.
- Clean up XFS_IFORK_Q usage and give it a better name.
- Fix more UAF bugs in the xattr code.
- SOB my tags.
- Fix some typos in the timestamp range documentation.
- Fix a few more memory leaks.
- Code cleanups and typo fixes.
- Fix an unlocked inode fork pointer access in getbmap"
* tag 'xfs-5.20-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (61 commits)
xfs: delete extra space and tab in blank line
xfs: fix NULL pointer dereference in xfs_getbmap()
xfs: Fix typo 'the the' in comment
xfs: Fix comment typo
xfs: don't leak memory when attr fork loading fails
xfs: fix for variable set but not used warning
xfs: xfs_buf cache destroy isn't RCU safe
xfs: delete unnecessary NULL checks
xfs: fix comment for start time value of inode with bigtime enabled
xfs: fix use-after-free in xattr node block inactivation
xfs: lockless buffer lookup
xfs: remove a superflous hash lookup when inserting new buffers
xfs: reduce the number of atomic when locking a buffer after lookup
xfs: merge xfs_buf_find() and xfs_buf_get_map()
xfs: break up xfs_buf_find() into individual pieces
xfs: add in-memory iunlink log item
xfs: add log item precommit operation
xfs: combine iunlink inode update functions
xfs: clean up xfs_iunlink_update_inode()
xfs: double link the unlinked inode list
...
- Fix an accounting bug that made NR_FILE_DIRTY grow without limit
when running xfstests
- Convert more of mpage to use folios
- Remove add_to_page_cache() and add_to_page_cache_locked()
- Convert find_get_pages_range() to filemap_get_folios()
- Improvements to the read_cache_page() family of functions
- Remove a few unnecessary checks of PageError
- Some straightforward filesystem conversions to use folios
- Split PageMovable users out from address_space_operations into their
own movable_operations
- Convert aops->migratepage to aops->migrate_folio
- Remove nobh support (Christoph Hellwig)
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Merge tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecache
Pull folio updates from Matthew Wilcox:
- Fix an accounting bug that made NR_FILE_DIRTY grow without limit
when running xfstests
- Convert more of mpage to use folios
- Remove add_to_page_cache() and add_to_page_cache_locked()
- Convert find_get_pages_range() to filemap_get_folios()
- Improvements to the read_cache_page() family of functions
- Remove a few unnecessary checks of PageError
- Some straightforward filesystem conversions to use folios
- Split PageMovable users out from address_space_operations into
their own movable_operations
- Convert aops->migratepage to aops->migrate_folio
- Remove nobh support (Christoph Hellwig)
* tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecache: (78 commits)
fs: remove the NULL get_block case in mpage_writepages
fs: don't call ->writepage from __mpage_writepage
fs: remove the nobh helpers
jfs: stop using the nobh helper
ext2: remove nobh support
ntfs3: refactor ntfs_writepages
mm/folio-compat: Remove migration compatibility functions
fs: Remove aops->migratepage()
secretmem: Convert to migrate_folio
hugetlb: Convert to migrate_folio
aio: Convert to migrate_folio
f2fs: Convert to filemap_migrate_folio()
ubifs: Convert to filemap_migrate_folio()
btrfs: Convert btrfs_migratepage to migrate_folio
mm/migrate: Add filemap_migrate_folio()
mm/migrate: Convert migrate_page() to migrate_folio()
nfs: Convert to migrate_folio
btrfs: Convert btree_migratepage to migrate_folio
mm/migrate: Convert expected_page_refs() to folio_expected_refs()
mm/migrate: Convert buffer_migrate_page() to buffer_migrate_folio()
...
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Merge tag 'for-5.20/block-2022-07-29' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe:
- Improve the type checking of request flags (Bart)
- Ensure queue mapping for a single queues always picks the right queue
(Bart)
- Sanitize the io priority handling (Jan)
- rq-qos race fix (Jinke)
- Reserved tags handling improvements (John)
- Separate memory alignment from file/disk offset aligment for O_DIRECT
(Keith)
- Add new ublk driver, userspace block driver using io_uring for
communication with the userspace backend (Ming)
- Use try_cmpxchg() to cleanup the code in various spots (Uros)
- Finally remove bdevname() (Christoph)
- Clean up the zoned device handling (Christoph)
- Clean up independent access range support (Christoph)
- Clean up and improve block sysfs handling (Christoph)
- Clean up and improve teardown of block devices.
This turns the usual two step process into something that is simpler
to implement and handle in block drivers (Christoph)
- Clean up chunk size handling (Christoph)
- Misc cleanups and fixes (Bart, Bo, Dan, GuoYong, Jason, Keith, Liu,
Ming, Sebastian, Yang, Ying)
* tag 'for-5.20/block-2022-07-29' of git://git.kernel.dk/linux-block: (178 commits)
ublk_drv: fix double shift bug
ublk_drv: make sure that correct flags(features) returned to userspace
ublk_drv: fix error handling of ublk_add_dev
ublk_drv: fix lockdep warning
block: remove __blk_get_queue
block: call blk_mq_exit_queue from disk_release for never added disks
blk-mq: fix error handling in __blk_mq_alloc_disk
ublk: defer disk allocation
ublk: rewrite ublk_ctrl_get_queue_affinity to not rely on hctx->cpumask
ublk: fold __ublk_create_dev into ublk_ctrl_add_dev
ublk: cleanup ublk_ctrl_uring_cmd
ublk: simplify ublk_ch_open and ublk_ch_release
ublk: remove the empty open and release block device operations
ublk: remove UBLK_IO_F_PREFLUSH
ublk: add a MAINTAINERS entry
block: don't allow the same type rq_qos add more than once
mmc: fix disk/queue leak in case of adding disk failure
ublk_drv: fix an IS_ERR() vs NULL check
ublk: remove UBLK_IO_F_INTEGRITY
ublk_drv: remove unneeded semicolon
...
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Merge tag 'for-5.20/io_uring-buffered-writes-2022-07-29' of git://git.kernel.dk/linux-block
Pull io_uring buffered writes support from Jens Axboe:
"This contains support for buffered writes, specifically for XFS. btrfs
is in progress, will be coming in the next release.
io_uring does support buffered writes on any file type, but since the
buffered write path just always -EAGAIN (or -EOPNOTSUPP) any attempt
to do so if IOCB_NOWAIT is set, any buffered write will effectively be
handled by io-wq offload. This isn't very efficient, and we even have
specific code in io-wq to serialize buffered writes to the same inode
to avoid further inefficiencies with thread offload.
This is particularly sad since most buffered writes don't block, they
simply copy data to a page and dirty it. With this pull request, we
can handle buffered writes a lot more effiently.
If balance_dirty_pages() needs to block, we back off on writes as
indicated.
This improves buffered write support by 2-3x.
Jan Kara helped with the mm bits for this, and Stefan handled the
fs/iomap/xfs/io_uring parts of it"
* tag 'for-5.20/io_uring-buffered-writes-2022-07-29' of git://git.kernel.dk/linux-block:
mm: honor FGP_NOWAIT for page cache page allocation
xfs: Add async buffered write support
xfs: Specify lockmode when calling xfs_ilock_for_iomap()
io_uring: Add tracepoint for short writes
io_uring: fix issue with io_write() not always undoing sb_start_write()
io_uring: Add support for async buffered writes
fs: Add async write file modification handling.
fs: Split off inode_needs_update_time and __file_update_time
fs: add __remove_file_privs() with flags parameter
fs: add a FMODE_BUF_WASYNC flags for f_mode
iomap: Return -EAGAIN from iomap_write_iter()
iomap: Add async buffered write support
iomap: Add flags parameter to iomap_page_create()
mm: Add balance_dirty_pages_ratelimited_flags() function
mm: Move updates of dirty_exceeded into one place
mm: Move starting of background writeback into the main balancing loop
There is nothing iomap-specific about iomap_migratepage(), and it fits
a pattern used by several other filesystems, so move it to mm/migrate.c,
convert it to be filemap_migrate_folio() and convert the iomap filesystems
to use it.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
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Merge tag 'fs.idmapped.vfsuid.v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull fs idmapping updates from Christian Brauner:
"This introduces the new vfs{g,u}id_t types we agreed on. Similar to
k{g,u}id_t the new types are just simple wrapper structs around
regular {g,u}id_t types.
They allow to establish a type safety boundary in the VFS for idmapped
mounts preventing confusion betwen {g,u}ids mapped into an idmapped
mount and {g,u}ids mapped into the caller's or the filesystem's
idmapping.
An initial set of helpers is introduced that allows to operate on
vfs{g,u}id_t types. We will remove all references to non-type safe
idmapped mounts helpers in the very near future. The patches do
already exist.
This converts the core attribute changing codepaths which become
significantly easier to reason about because of this change.
Just a few highlights here as the patches give detailed overviews of
what is happening in the commit messages:
- The kernel internal struct iattr contains type safe vfs{g,u}id_t
values clearly communicating that these values have to take a given
mount's idmapping into account.
- The ownership values placed in struct iattr to change ownership are
identical for idmapped and non-idmapped mounts going forward. This
also allows to simplify stacking filesystems such as overlayfs that
change attributes In other words, they always represent the values.
- Instead of open coding checks for whether ownership changes have
been requested and an actual update of the inode is required we now
have small static inline wrappers that abstract this logic away
removing a lot of code duplication from individual filesystems that
all open-coded the same checks"
* tag 'fs.idmapped.vfsuid.v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
mnt_idmapping: align kernel doc and parameter order
mnt_idmapping: use new helpers in mapped_fs{g,u}id()
fs: port HAS_UNMAPPED_ID() to vfs{g,u}id_t
mnt_idmapping: return false when comparing two invalid ids
attr: fix kernel doc
attr: port attribute changes to new types
security: pass down mount idmapping to setattr hook
quota: port quota helpers mount ids
fs: port to iattr ownership update helpers
fs: introduce tiny iattr ownership update helpers
fs: use mount types in iattr
fs: add two type safe mapping helpers
mnt_idmapping: add vfs{g,u}id_t
delete extra space and tab in blank line, there is no functional change.
Reported-by: Hacash Robot <hacashRobot@santino.com>
Signed-off-by: Xie Shaowen <studentxswpy@163.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Failure notification is not supported on partitions. So, when we mount a
reflink enabled xfs on a partition with dax option, let it fail with
-EINVAL code.
Link: https://lkml.kernel.org/r/20220609143435.393724-1-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This adds the async buffered write support to XFS. For async buffered
write requests, the request will return -EAGAIN if the ilock cannot be
obtained immediately.
Signed-off-by: Stefan Roesch <shr@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20220623175157.1715274-15-shr@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch changes the helper function xfs_ilock_for_iomap such that the
lock mode must be passed in.
Signed-off-by: Stefan Roesch <shr@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20220623175157.1715274-14-shr@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Replace 'the the' with 'the' in the comment.
Signed-off-by: Slark Xiao <slark_xiao@163.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
The double `the' is duplicated in line 552, remove one.
Signed-off-by: Xin Gao <gaoxin@cdjrlc.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
I observed the following evidence of a memory leak while running xfs/399
from the xfs fsck test suite (edited for brevity):
XFS (sde): Metadata corruption detected at xfs_attr_shortform_verify_struct.part.0+0x7b/0xb0 [xfs], inode 0x1172 attr fork
XFS: Assertion failed: ip->i_af.if_u1.if_data == NULL, file: fs/xfs/libxfs/xfs_inode_fork.c, line: 315
------------[ cut here ]------------
WARNING: CPU: 2 PID: 91635 at fs/xfs/xfs_message.c:104 assfail+0x46/0x4a [xfs]
CPU: 2 PID: 91635 Comm: xfs_scrub Tainted: G W 5.19.0-rc7-xfsx #rc7 6e6475eb29fd9dda3181f81b7ca7ff961d277a40
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
RIP: 0010:assfail+0x46/0x4a [xfs]
Call Trace:
<TASK>
xfs_ifork_zap_attr+0x7c/0xb0
xfs_iformat_attr_fork+0x86/0x110
xfs_inode_from_disk+0x41d/0x480
xfs_iget+0x389/0xd70
xfs_bulkstat_one_int+0x5b/0x540
xfs_bulkstat_iwalk+0x1e/0x30
xfs_iwalk_ag_recs+0xd1/0x160
xfs_iwalk_run_callbacks+0xb9/0x180
xfs_iwalk_ag+0x1d8/0x2e0
xfs_iwalk+0x141/0x220
xfs_bulkstat+0x105/0x180
xfs_ioc_bulkstat.constprop.0.isra.0+0xc5/0x130
xfs_file_ioctl+0xa5f/0xef0
__x64_sys_ioctl+0x82/0xa0
do_syscall_64+0x2b/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
This newly-added assertion checks that there aren't any incore data
structures hanging off the incore fork when we're trying to reset its
contents. From the call trace, it is evident that iget was trying to
construct an incore inode from the ondisk inode, but the attr fork
verifier failed and we were trying to undo all the memory allocations
that we had done earlier.
The three assertions in xfs_ifork_zap_attr check that the caller has
already called xfs_idestroy_fork, which clearly has not been done here.
As the zap function then zeroes the pointers, we've effectively leaked
the memory.
The shortest change would have been to insert an extra call to
xfs_idestroy_fork, but it makes more sense to bundle the _idestroy_fork
call into _zap_attr, since all other callsites call _idestroy_fork
immediately prior to calling _zap_attr. IOWs, it eliminates one way to
fail.
Note: This change only applies cleanly to 2ed5b09b3e, since we just
reworked the attr fork lifetime. However, I think this memory leak has
existed since 0f45a1b20c, since the chain xfs_iformat_attr_fork ->
xfs_iformat_local -> xfs_init_local_fork will allocate
ifp->if_u1.if_data, but if xfs_ifork_verify_local_attr fails,
xfs_iformat_attr_fork will free i_afp without freeing any of the stuff
hanging off i_afp. The solution for older kernels I think is to add the
missing call to xfs_idestroy_fork just prior to calling kmem_cache_free.
Found by fuzzing a.sfattr.hdr.totsize = lastbit in xfs/399.
Fixes: 2ed5b09b3e ("xfs: make inode attribute forks a permanent part of struct xfs_inode")
Probably-Fixes: 0f45a1b20c ("xfs: improve local fork verification")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Fix below kernel warning:
fs/xfs/scrub/repair.c:539:19: warning: variable 'agno' set but not used [-Wunused-but-set-variable]
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: sunliming <sunliming@kylinos.cn>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Darrick and Sachin Sant reported that xfs/435 and xfs/436 would
report an non-empty xfs_buf slab on module remove. This isn't easily
to reproduce, but is clearly a side effect of converting the buffer
caceh to RUC freeing and lockless lookups. Sachin bisected and
Darrick hit it when testing the patchset directly.
Turns out that the xfs_buf slab is not destroyed when all the other
XFS slab caches are destroyed. Instead, it's got it's own little
wrapper function that gets called separately, and so it doesn't have
an rcu_barrier() call in it that is needed to drain all the rcu
callbacks before the slab is destroyed.
Fix it by removing the xfs_buf_init/terminate wrappers that just
allocate and destroy the xfs_buf slab, and move them to the same
place that all the other slab caches are set up and destroyed.
Reported-and-tested-by: Sachin Sant <sachinp@linux.ibm.com>
Fixes: 298f342245 ("xfs: lockless buffer lookup")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
These NULL check are no long needed after commit 2ed5b09b3e ("xfs:
make inode attribute forks a permanent part of struct xfs_inode").
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
The 'ctime', 'mtime', and 'atime' for inode is the type of
'xfs_timestamp_t', which is a 64-bit type:
/* fs/xfs/libxfs/xfs_format.h begin */
typedef __be64 xfs_timestamp_t;
/* fs/xfs/libxfs/xfs_format.h end */
When the 'bigtime' feature is disabled, this 64-bit type is splitted
into two parts of 32-bit, one part is encoded for seconds since
1970-01-01 00:00:00 UTC, the other part is encoded for nanoseconds
above the seconds, this two parts are the type of
'xfs_legacy_timestamp' and the min and max time value of this type are
defined as macros 'XFS_LEGACY_TIME_MIN' and 'XFS_LEGACY_TIME_MAX':
/* fs/xfs/libxfs/xfs_format.h begin */
struct xfs_legacy_timestamp {
__be32 t_sec; /* timestamp seconds */
__be32 t_nsec; /* timestamp nanoseconds */
};
#define XFS_LEGACY_TIME_MIN ((int64_t)S32_MIN)
#define XFS_LEGACY_TIME_MAX ((int64_t)S32_MAX)
/* fs/xfs/libxfs/xfs_format.h end */
/* include/linux/limits.h begin */
#define U32_MAX ((u32)~0U)
#define S32_MAX ((s32)(U32_MAX >> 1))
#define S32_MIN ((s32)(-S32_MAX - 1))
/* include/linux/limits.h end */
'XFS_LEGACY_TIME_MIN' is the min time value of the
'xfs_legacy_timestamp', that is -(2^31) seconds relative to the
1970-01-01 00:00:00 UTC, it can be converted to human-friendly time
value by 'date' command:
/* command begin */
[root@~]# date --utc -d '@0' +'%Y-%m-%d %H:%M:%S'
1970-01-01 00:00:00
[root@~]# date --utc -d "@`echo '-(2^31)'|bc`" +'%Y-%m-%d %H:%M:%S'
1901-12-13 20:45:52
[root@~]#
/* command end */
When 'bigtime' feature is enabled, this 64-bit type becomes a 64-bit
nanoseconds counter, with the start time value is the min time value of
'xfs_legacy_timestamp'(start time means the value of 64-bit nanoseconds
counter is 0). We have already caculated the min time value of
'xfs_legacy_timestamp', that is 1901-12-13 20:45:52 UTC, but the comment
for the start time value of inode with 'bigtime' feature enabled writes
the value is 1901-12-31 20:45:52 UTC:
/* fs/xfs/libxfs/xfs_format.h begin */
/*
* XFS Timestamps
* ==============
* When the bigtime feature is enabled, ondisk inode timestamps become an
* unsigned 64-bit nanoseconds counter. This means that the bigtime inode
* timestamp epoch is the start of the classic timestamp range, which is
* Dec 31 20:45:52 UTC 1901. ...
...
*/
/* fs/xfs/libxfs/xfs_format.h end */
That is a typo, and this patch corrects the typo, from 'Dec 31' to
'Dec 13'.
Suggested-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Xiaole He <hexiaole@kylinos.cn>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Introduce xfs_mmaplock_two_inodes_and_break_dax_layout() for dax files who
are going to be deduped. After that, call compare range function only
when files are both DAX or not.
Link: https://lkml.kernel.org/r/20220603053738.1218681-15-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.wiliams@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In fsdax mode, WRITE and ZERO on a shared extent need CoW performed.
After that, new allocated extents needs to be remapped to the file. So,
add a CoW identification in ->iomap_begin(), and implement ->iomap_end()
to do the remapping work.
[akpm@linux-foundation.org: make xfs_dax_fault() static]
Link: https://lkml.kernel.org/r/20220603053738.1218681-14-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.wiliams@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
With dax we cannot deal with readpage() etc. So, we create a dax
comparison function which is similar with vfs_dedupe_file_range_compare().
And introduce dax_remap_file_range_prep() for filesystem use.
Link: https://lkml.kernel.org/r/20220603053738.1218681-13-ruansy.fnst@fujitsu.com
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.wiliams@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Introduce xfs_notify_failure.c to handle failure related works, such as
implement ->notify_failure(), register/unregister dax holder in xfs, and
so on.
If the rmap feature of XFS enabled, we can query it to find files and
metadata which are associated with the corrupt data. For now all we do is
kill processes with that file mapped into their address spaces, but future
patches could actually do something about corrupt metadata.
After that, the memory failure needs to notify the processes who are using
those files.
Link: https://lkml.kernel.org/r/20220603053738.1218681-7-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.wiliams@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "v14 fsdax-rmap + v11 fsdax-reflink", v2.
The patchset fsdax-rmap is aimed to support shared pages tracking for
fsdax.
It moves owner tracking from dax_assocaite_entry() to pmem device driver,
by introducing an interface ->memory_failure() for struct pagemap. This
interface is called by memory_failure() in mm, and implemented by pmem
device.
Then call holder operations to find the filesystem which the corrupted
data located in, and call filesystem handler to track files or metadata
associated with this page.
Finally we are able to try to fix the corrupted data in filesystem and do
other necessary processing, such as killing processes who are using the
files affected.
The call trace is like this:
memory_failure()
|* fsdax case
|------------
|pgmap->ops->memory_failure() => pmem_pgmap_memory_failure()
| dax_holder_notify_failure() =>
| dax_device->holder_ops->notify_failure() =>
| - xfs_dax_notify_failure()
| |* xfs_dax_notify_failure()
| |--------------------------
| | xfs_rmap_query_range()
| | xfs_dax_failure_fn()
| | * corrupted on metadata
| | try to recover data, call xfs_force_shutdown()
| | * corrupted on file data
| | try to recover data, call mf_dax_kill_procs()
|* normal case
|-------------
|mf_generic_kill_procs()
The patchset fsdax-reflink attempts to add CoW support for fsdax, and
takes XFS, which has both reflink and fsdax features, as an example.
One of the key mechanisms needed to be implemented in fsdax is CoW. Copy
the data from srcmap before we actually write data to the destination
iomap. And we just copy range in which data won't be changed.
Another mechanism is range comparison. In page cache case, readpage() is
used to load data on disk to page cache in order to be able to compare
data. In fsdax case, readpage() does not work. So, we need another
compare data with direct access support.
With the two mechanisms implemented in fsdax, we are able to make reflink
and fsdax work together in XFS.
This patch (of 14):
To easily track filesystem from a pmem device, we introduce a holder for
dax_device structure, and also its operation. This holder is used to
remember who is using this dax_device:
- When it is the backend of a filesystem, the holder will be the
instance of this filesystem.
- When this pmem device is one of the targets in a mapped device, the
holder will be this mapped device. In this case, the mapped device
has its own dax_device and it will follow the first rule. So that we
can finally track to the filesystem we needed.
The holder and holder_ops will be set when filesystem is being mounted,
or an target device is being activated.
Link: https://lkml.kernel.org/r/20220603053738.1218681-1-ruansy.fnst@fujitsu.com
Link: https://lkml.kernel.org/r/20220603053738.1218681-2-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.wiliams@intel.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for the
combination of a request operation with request flags.
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-63-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The kernel build robot reported a UAF error while running xfs/433
(edited somewhat for brevity):
BUG: KASAN: use-after-free in xfs_attr3_node_inactive (fs/xfs/xfs_attr_inactive.c:214) xfs
Read of size 4 at addr ffff88820ac2bd44 by task kworker/0:2/139
CPU: 0 PID: 139 Comm: kworker/0:2 Tainted: G S 5.19.0-rc2-00004-g7cf2b0f9611b #1
Hardware name: Hewlett-Packard p6-1451cx/2ADA, BIOS 8.15 02/05/2013
Workqueue: xfs-inodegc/sdb4 xfs_inodegc_worker [xfs]
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:107 (discriminator 1))
print_address_description+0x1f/0x200
print_report.cold (mm/kasan/report.c:430)
kasan_report (mm/kasan/report.c:162 mm/kasan/report.c:493)
xfs_attr3_node_inactive (fs/xfs/xfs_attr_inactive.c:214) xfs
xfs_attr3_root_inactive (fs/xfs/xfs_attr_inactive.c:296) xfs
xfs_attr_inactive (fs/xfs/xfs_attr_inactive.c:371) xfs
xfs_inactive (fs/xfs/xfs_inode.c:1781) xfs
xfs_inodegc_worker (fs/xfs/xfs_icache.c:1837 fs/xfs/xfs_icache.c:1860) xfs
process_one_work
worker_thread
kthread
ret_from_fork
</TASK>
Allocated by task 139:
kasan_save_stack (mm/kasan/common.c:39)
__kasan_slab_alloc (mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:469)
kmem_cache_alloc (mm/slab.h:750 mm/slub.c:3214 mm/slub.c:3222 mm/slub.c:3229 mm/slub.c:3239)
_xfs_buf_alloc (include/linux/instrumented.h:86 include/linux/atomic/atomic-instrumented.h:41 fs/xfs/xfs_buf.c:232) xfs
xfs_buf_get_map (fs/xfs/xfs_buf.c:660) xfs
xfs_buf_read_map (fs/xfs/xfs_buf.c:777) xfs
xfs_trans_read_buf_map (fs/xfs/xfs_trans_buf.c:289) xfs
xfs_da_read_buf (fs/xfs/libxfs/xfs_da_btree.c:2652) xfs
xfs_da3_node_read (fs/xfs/libxfs/xfs_da_btree.c:392) xfs
xfs_attr3_root_inactive (fs/xfs/xfs_attr_inactive.c:272) xfs
xfs_attr_inactive (fs/xfs/xfs_attr_inactive.c:371) xfs
xfs_inactive (fs/xfs/xfs_inode.c:1781) xfs
xfs_inodegc_worker (fs/xfs/xfs_icache.c:1837 fs/xfs/xfs_icache.c:1860) xfs
process_one_work
worker_thread
kthread
ret_from_fork
Freed by task 139:
kasan_save_stack (mm/kasan/common.c:39)
kasan_set_track (mm/kasan/common.c:45)
kasan_set_free_info (mm/kasan/generic.c:372)
__kasan_slab_free (mm/kasan/common.c:368 mm/kasan/common.c:328 mm/kasan/common.c:374)
kmem_cache_free (mm/slub.c:1753 mm/slub.c:3507 mm/slub.c:3524)
xfs_buf_rele (fs/xfs/xfs_buf.c:1040) xfs
xfs_attr3_node_inactive (fs/xfs/xfs_attr_inactive.c:210) xfs
xfs_attr3_root_inactive (fs/xfs/xfs_attr_inactive.c:296) xfs
xfs_attr_inactive (fs/xfs/xfs_attr_inactive.c:371) xfs
xfs_inactive (fs/xfs/xfs_inode.c:1781) xfs
xfs_inodegc_worker (fs/xfs/xfs_icache.c:1837 fs/xfs/xfs_icache.c:1860) xfs
process_one_work
worker_thread
kthread
ret_from_fork
I reproduced this for my own satisfaction, and got the same report,
along with an extra morsel:
The buggy address belongs to the object at ffff88802103a800
which belongs to the cache xfs_buf of size 432
The buggy address is located 396 bytes inside of
432-byte region [ffff88802103a800, ffff88802103a9b0)
I tracked this code down to:
error = xfs_trans_get_buf(*trans, mp->m_ddev_targp,
child_blkno,
XFS_FSB_TO_BB(mp, mp->m_attr_geo->fsbcount), 0,
&child_bp);
if (error)
return error;
error = bp->b_error;
That doesn't look right -- I think this should be dereferencing
child_bp, not bp. Looking through the codebase history, I think this
was added by commit 2911edb653 ("xfs: remove the mappedbno argument to
xfs_da_get_buf"), which replaced a call to xfs_da_get_buf with the
current call to xfs_trans_get_buf. Not sure why we trans_brelse'd @bp
earlier in the function, but I'm guessing it's to avoid pinning too many
buffers in memory while we inactivate the bottom of the attr tree.
Hence we now have to get the buffer back.
I /think/ this was supposed to check child_bp->b_error and fail the rest
of the invalidation if child_bp had experienced any kind of IO or
corruption error. I bet the xfs_da3_node_read earlier in the loop will
catch most cases of incoming on-disk corruption which makes this check
mostly moot unless someone corrupts the buffer and the AIL pushes it out
to disk while the buffer's unlocked.
In the first case we'll never get to the bad check, and in the second
case the AIL will shut down the log, at which point there's no reason to
check b_error. Remove the check, and null out @bp to avoid this problem
in the future.
Cc: hch@lst.de
Reported-by: kernel test robot <oliver.sang@intel.com>
Fixes: 2911edb653 ("xfs: remove the mappedbno argument to xfs_da_get_buf")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
This series fixes a use-after-free bug that syzbot uncovered. The UAF
itself is a result of a race condition between getxattr and removexattr
because callers to getxattr do not necessarily take any sort of locks
before calling into the filesystem.
Although the race condition itself can be fixed through clever use of a
memory barrier, further consideration of the use cases of extended
attributes shows that most files always have at least one attribute, so
we might as well make them permanent.
v2: Minor tweaks suggested by Dave, and convert some more macros to
helper functions.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Merge tag 'make-attr-fork-permanent-5.20_2022-07-14' of git://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into xfs-5.20-mergeB
xfs: make attr forks permanent
This series fixes a use-after-free bug that syzbot uncovered. The UAF
itself is a result of a race condition between getxattr and removexattr
because callers to getxattr do not necessarily take any sort of locks
before calling into the filesystem.
Although the race condition itself can be fixed through clever use of a
memory barrier, further consideration of the use cases of extended
attributes shows that most files always have at least one attribute, so
we might as well make them permanent.
v2: Minor tweaks suggested by Dave, and convert some more macros to
helper functions.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
* tag 'make-attr-fork-permanent-5.20_2022-07-14' of git://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
xfs: replace inode fork size macros with functions
xfs: replace XFS_IFORK_Q with a proper predicate function
xfs: use XFS_IFORK_Q to determine the presence of an xattr fork
xfs: make inode attribute forks a permanent part of struct xfs_inode
xfs: convert XFS_IFORK_PTR to a static inline helper
Current work to merge the XFS inode life cycle with the VFS inode
life cycle is finding some interesting issues. If we have a path
that hits buffer trylocks fairly hard (e.g. a non-blocking
background inode freeing function), we end up hitting massive
contention on the buffer cache hash locks:
- 92.71% 0.05% [kernel] [k] xfs_inodegc_worker
- 92.67% xfs_inodegc_worker
- 92.13% xfs_inode_unlink
- 91.52% xfs_inactive_ifree
- 85.63% xfs_read_agi
- 85.61% xfs_trans_read_buf_map
- 85.59% xfs_buf_read_map
- xfs_buf_get_map
- 85.55% xfs_buf_find
- 72.87% _raw_spin_lock
- do_raw_spin_lock
71.86% __pv_queued_spin_lock_slowpath
- 8.74% xfs_buf_rele
- 7.88% _raw_spin_lock
- 7.88% do_raw_spin_lock
7.63% __pv_queued_spin_lock_slowpath
- 1.70% xfs_buf_trylock
- 1.68% down_trylock
- 1.41% _raw_spin_lock_irqsave
- 1.39% do_raw_spin_lock
__pv_queued_spin_lock_slowpath
- 0.76% _raw_spin_unlock
0.75% do_raw_spin_unlock
This is basically hammering the pag->pag_buf_lock from lots of CPUs
doing trylocks at the same time. Most of the buffer trylock
operations ultimately fail after we've done the lookup, so we're
really hammering the buf hash lock whilst making no progress.
We can also see significant spinlock traffic on the same lock just
under normal operation when lots of tasks are accessing metadata
from the same AG, so let's avoid all this by creating a lookup fast
path which leverages the rhashtable's ability to do RCU protected
lookups.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
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Merge tag 'xfs-buf-lockless-lookup-5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs into xfs-5.20-mergeB
xfs: lockless buffer cache lookups
Current work to merge the XFS inode life cycle with the VFS inode
life cycle is finding some interesting issues. If we have a path
that hits buffer trylocks fairly hard (e.g. a non-blocking
background inode freeing function), we end up hitting massive
contention on the buffer cache hash locks:
- 92.71% 0.05% [kernel] [k] xfs_inodegc_worker
- 92.67% xfs_inodegc_worker
- 92.13% xfs_inode_unlink
- 91.52% xfs_inactive_ifree
- 85.63% xfs_read_agi
- 85.61% xfs_trans_read_buf_map
- 85.59% xfs_buf_read_map
- xfs_buf_get_map
- 85.55% xfs_buf_find
- 72.87% _raw_spin_lock
- do_raw_spin_lock
71.86% __pv_queued_spin_lock_slowpath
- 8.74% xfs_buf_rele
- 7.88% _raw_spin_lock
- 7.88% do_raw_spin_lock
7.63% __pv_queued_spin_lock_slowpath
- 1.70% xfs_buf_trylock
- 1.68% down_trylock
- 1.41% _raw_spin_lock_irqsave
- 1.39% do_raw_spin_lock
__pv_queued_spin_lock_slowpath
- 0.76% _raw_spin_unlock
0.75% do_raw_spin_unlock
This is basically hammering the pag->pag_buf_lock from lots of CPUs
doing trylocks at the same time. Most of the buffer trylock
operations ultimately fail after we've done the lookup, so we're
really hammering the buf hash lock whilst making no progress.
We can also see significant spinlock traffic on the same lock just
under normal operation when lots of tasks are accessing metadata
from the same AG, so let's avoid all this by creating a lookup fast
path which leverages the rhashtable's ability to do RCU protected
lookups.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
* tag 'xfs-buf-lockless-lookup-5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs:
xfs: lockless buffer lookup
xfs: remove a superflous hash lookup when inserting new buffers
xfs: reduce the number of atomic when locking a buffer after lookup
xfs: merge xfs_buf_find() and xfs_buf_get_map()
xfs: break up xfs_buf_find() into individual pieces
xfs: rework xfs_buf_incore() API
To facilitate future improvements in inode logging and improving
inode cluster buffer locking order consistency, we need a new
mechanism for defering inode cluster buffer modifications during
unlinked list modifications.
The unlinked inode list buffer locking is complex. The unlinked
list is unordered - we add to the tail, remove from where-ever the
inode is in the list. Hence we might need to lock two inode buffers
here (previous inode in list and the one being removed). While we
can order the locking of these buffers correctly within the confines
of the unlinked list, there may be other inodes that need buffer
locking in the same transaction. e.g. O_TMPFILE being linked into a
directory also modifies the directory inode.
Hence we need a mechanism for defering unlinked inode list updates
until a point where we know that all modifications have been made
and all that remains is to lock and modify the cluster buffers.
We can do this by first observing that we serialise unlinked list
modifications by holding the AGI buffer lock. IOWs, the AGI is going
to be locked until the transaction commits any time we modify the
unlinked list. Hence it doesn't matter when in the unlink
transactions that we actually load, lock and modify the inode
cluster buffer.
We add an in-memory unlinked inode log item to defer the inode
cluster buffer update to transaction commit time where it can be
ordered with all the other inode cluster operations that need to be
done. Essentially all we need to do is record the inodes that need
to have their unlinked list pointer updated in a new log item that
we attached to the transaction.
This log item exists purely for the purpose of delaying the update
of the unlinked list pointer until the inode cluster buffer can be
locked in the correct order around the other inode cluster buffers.
It plays no part in the actual commit, and there's no change to
anything that is written to the log. i.e. the inode cluster buffers
still have to be fully logged here (not just ordered) as log
recovery depedends on this to replay mods to the unlinked inode
list.
Hence if we add a "precommit" hook into xfs_trans_commit()
to run a "precommit" operation on these iunlink log items, we can
delay the locking, modification and logging of the inode cluster
buffer until after all other modifications have been made. The
precommit hook reuires us to sort the items that are going to be run
so that we can lock precommit items in the correct order as we
perform the modifications they describe.
To make this unlinked inode list processing simpler and easier to
implement as a log item, we need to change the way we track the
unlinked list in memory. Starting from the observation that an inode
on the unlinked list is pinned in memory by the VFS, we can use the
xfs_inode itself to track the unlinked list. To do this efficiently,
we want the unlinked list to be a double linked list. The problem
here is that we need a list per AGI unlinked list, and there are 64
of these per AGI. The approach taken in this patchset is to shadow
the AGI unlinked list heads in the perag, and link inodes by agino,
hence requiring only 8 extra bytes per inode to track this state.
We can then use the agino pointers for lockless inode cache lookups
to retreive the inode. The aginos in the inode are modified only
under the AGI lock, just like the cluster buffer pointers, so we
don't need any extra locking here. The i_next_unlinked field tracks
the on-disk value of the unlinked list, and the i_prev_unlinked is a
purely in-memory pointer that enables us to efficiently remove
inodes from the middle of the list.
This results in moving a lot of the unlink modification work into
the precommit operations on the unlink log item. Tracking all the
unlinked inodes in the inodes themselves also gets rid of the
unlinked list reference hash table that is used to track this back
pointer relationship. This greatly simplifies the the unlinked list
modification code, and removes memory allocations in this hot path
to track back pointers. This, overall, slightly reduces the CPU
overhead of the unlink path.
The result of this log item means that we move all the actual
manipulation of objects to be logged out of the iunlink path and
into the iunlink item. This allows for future optimisation of this
mechanism without needing changes to high level unlink path, as
well as making the unlink lock ordering predictable and synchronised
with other operations that may require inode cluster locking.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
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Merge tag 'xfs-iunlink-item-5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs into xfs-5.20-mergeB
xfs: introduce in-memory inode unlink log items
To facilitate future improvements in inode logging and improving
inode cluster buffer locking order consistency, we need a new
mechanism for defering inode cluster buffer modifications during
unlinked list modifications.
The unlinked inode list buffer locking is complex. The unlinked
list is unordered - we add to the tail, remove from where-ever the
inode is in the list. Hence we might need to lock two inode buffers
here (previous inode in list and the one being removed). While we
can order the locking of these buffers correctly within the confines
of the unlinked list, there may be other inodes that need buffer
locking in the same transaction. e.g. O_TMPFILE being linked into a
directory also modifies the directory inode.
Hence we need a mechanism for defering unlinked inode list updates
until a point where we know that all modifications have been made
and all that remains is to lock and modify the cluster buffers.
We can do this by first observing that we serialise unlinked list
modifications by holding the AGI buffer lock. IOWs, the AGI is going
to be locked until the transaction commits any time we modify the
unlinked list. Hence it doesn't matter when in the unlink
transactions that we actually load, lock and modify the inode
cluster buffer.
We add an in-memory unlinked inode log item to defer the inode
cluster buffer update to transaction commit time where it can be
ordered with all the other inode cluster operations that need to be
done. Essentially all we need to do is record the inodes that need
to have their unlinked list pointer updated in a new log item that
we attached to the transaction.
This log item exists purely for the purpose of delaying the update
of the unlinked list pointer until the inode cluster buffer can be
locked in the correct order around the other inode cluster buffers.
It plays no part in the actual commit, and there's no change to
anything that is written to the log. i.e. the inode cluster buffers
still have to be fully logged here (not just ordered) as log
recovery depedends on this to replay mods to the unlinked inode
list.
Hence if we add a "precommit" hook into xfs_trans_commit()
to run a "precommit" operation on these iunlink log items, we can
delay the locking, modification and logging of the inode cluster
buffer until after all other modifications have been made. The
precommit hook reuires us to sort the items that are going to be run
so that we can lock precommit items in the correct order as we
perform the modifications they describe.
To make this unlinked inode list processing simpler and easier to
implement as a log item, we need to change the way we track the
unlinked list in memory. Starting from the observation that an inode
on the unlinked list is pinned in memory by the VFS, we can use the
xfs_inode itself to track the unlinked list. To do this efficiently,
we want the unlinked list to be a double linked list. The problem
here is that we need a list per AGI unlinked list, and there are 64
of these per AGI. The approach taken in this patchset is to shadow
the AGI unlinked list heads in the perag, and link inodes by agino,
hence requiring only 8 extra bytes per inode to track this state.
We can then use the agino pointers for lockless inode cache lookups
to retreive the inode. The aginos in the inode are modified only
under the AGI lock, just like the cluster buffer pointers, so we
don't need any extra locking here. The i_next_unlinked field tracks
the on-disk value of the unlinked list, and the i_prev_unlinked is a
purely in-memory pointer that enables us to efficiently remove
inodes from the middle of the list.
This results in moving a lot of the unlink modification work into
the precommit operations on the unlink log item. Tracking all the
unlinked inodes in the inodes themselves also gets rid of the
unlinked list reference hash table that is used to track this back
pointer relationship. This greatly simplifies the the unlinked list
modification code, and removes memory allocations in this hot path
to track back pointers. This, overall, slightly reduces the CPU
overhead of the unlink path.
The result of this log item means that we move all the actual
manipulation of objects to be logged out of the iunlink path and
into the iunlink item. This allows for future optimisation of this
mechanism without needing changes to high level unlink path, as
well as making the unlink lock ordering predictable and synchronised
with other operations that may require inode cluster locking.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
* tag 'xfs-iunlink-item-5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs:
xfs: add in-memory iunlink log item
xfs: add log item precommit operation
xfs: combine iunlink inode update functions
xfs: clean up xfs_iunlink_update_inode()
xfs: double link the unlinked inode list
xfs: introduce xfs_iunlink_lookup
xfs: refactor xlog_recover_process_iunlinks()
xfs: track the iunlink list pointer in the xfs_inode
xfs: factor the xfs_iunlink functions
xfs: flush inode gc workqueue before clearing agi bucket
Now that we have a standalone fast path for buffer lookup, we can
easily convert it to use rcu lookups. When we continually hammer the
buffer cache with trylock lookups, we end up with a huge amount of
lock contention on the per-ag buffer hash locks:
- 92.71% 0.05% [kernel] [k] xfs_inodegc_worker
- 92.67% xfs_inodegc_worker
- 92.13% xfs_inode_unlink
- 91.52% xfs_inactive_ifree
- 85.63% xfs_read_agi
- 85.61% xfs_trans_read_buf_map
- 85.59% xfs_buf_read_map
- xfs_buf_get_map
- 85.55% xfs_buf_find
- 72.87% _raw_spin_lock
- do_raw_spin_lock
71.86% __pv_queued_spin_lock_slowpath
- 8.74% xfs_buf_rele
- 7.88% _raw_spin_lock
- 7.88% do_raw_spin_lock
7.63% __pv_queued_spin_lock_slowpath
- 1.70% xfs_buf_trylock
- 1.68% down_trylock
- 1.41% _raw_spin_lock_irqsave
- 1.39% do_raw_spin_lock
__pv_queued_spin_lock_slowpath
- 0.76% _raw_spin_unlock
0.75% do_raw_spin_unlock
This is basically hammering the pag->pag_buf_lock from lots of CPUs
doing trylocks at the same time. Most of the buffer trylock
operations ultimately fail after we've done the lookup, so we're
really hammering the buf hash lock whilst making no progress.
We can also see significant spinlock traffic on the same lock just
under normal operation when lots of tasks are accessing metadata
from the same AG, so let's avoid all this by converting the lookup
fast path to leverages the rhashtable's ability to do rcu protected
lookups.
We avoid races with the buffer release path by using
atomic_inc_not_zero() on the buffer hold count. Any buffer that is
in the LRU will have a non-zero count, thereby allowing the lockless
fast path to be taken in most cache hit situations. If the buffer
hold count is zero, then it is likely going through the release path
so in that case we fall back to the existing lookup miss slow path.
The slow path will then do an atomic lookup and insert under the
buffer hash lock and hence serialise correctly against buffer
release freeing the buffer.
The use of rcu protected lookups means that buffer handles now need
to be freed by RCU callbacks (same as inodes). We still free the
buffer pages before the RCU callback - we won't be trying to access
them at all on a buffer that has zero references - but we need the
buffer handle itself to be present for the entire rcu protected read
side to detect a zero hold count correctly.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Currently on the slow path insert we repeat the initial hash table
lookup before we attempt the insert, resulting in a two traversals
of the hash table to ensure the insert is valid. The rhashtable API
provides a method for an atomic lookup and insert operation, so we
can avoid one of the hash table traversals by using this method.
Adapted from a large patch containing this optimisation by Christoph
Hellwig.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Avoid an extra atomic operation in the non-trylock case by only
doing a trylock if the XBF_TRYLOCK flag is set. This follows the
pattern in the IO path with NOWAIT semantics where the
"trylock-fail-lock" path showed 5-10% reduced throughput compared to
just using single lock call when not under NOWAIT conditions. So
make that same change here, too.
See commit 942491c9e6 ("xfs: fix AIM7 regression") for details.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
[hch: split from a larger patch]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Now that we factored xfs_buf_find(), we can start separating into
distinct fast and slow paths from xfs_buf_get_map(). We start by
moving the lookup map and perag setup to _get_map(), and then move
all the specifics of the fast path lookup into xfs_buf_lookup()
and call it directly from _get_map(). We the move all the slow path
code to xfs_buf_find_insert(), which is now also called directly
from _get_map(). As such, xfs_buf_find() now goes away.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
xfs_buf_find() is made up of three main parts: lookup, insert and
locking. The interactions with xfs_buf_get_map() require it to be
called twice - once for a pure lookup, and again on lookup failure
so the insert path can be run. We want to simplify this down a lot,
so split it into a fast path lookup, a slow path insert and a "lock
the found buffer" helper. This will then let us integrate these
operations more effectively into xfs_buf_get_map() in future
patches.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Now that we have a clean operation to update the di_next_unlinked
field of inode cluster buffers, we can easily defer this operation
to transaction commit time so we can order the inode cluster buffer
locking consistently.
To do this, we introduce a new in-memory log item to track the
unlinked list item modification that we are going to make. This
follows the same observations as the in-memory double linked list
used to track unlinked inodes in that the inodes on the list are
pinned in memory and cannot go away, and hence we can simply
reference them for the duration of the transaction without needing
to take active references or pin them or look them up.
This allows us to pass the xfs_inode to the transaction commit code
along with the modification to be made, and then order the logged
modifications via the ->iop_sort and ->iop_precommit operations
for the new log item type. As this is an in-memory log item, it
doesn't have formatting, CIL or AIL operational hooks - it exists
purely to run the inode unlink modifications and is then removed
from the transaction item list and freed once the precommit
operation has run.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
For inodes that are dirty, we have an attached cluster buffer that
we want to use to track the dirty inode through the AIL.
Unfortunately, locking the cluster buffer and adding it to the
transaction when the inode is first logged in a transaction leads to
buffer lock ordering inversions.
The specific problem is ordering against the AGI buffer. When
modifying unlinked lists, the buffer lock order is AGI -> inode
cluster buffer as the AGI buffer lock serialises all access to the
unlinked lists. Unfortunately, functionality like xfs_droplink()
logs the inode before calling xfs_iunlink(), as do various directory
manipulation functions. The inode can be logged way down in the
stack as far as the bmapi routines and hence, without a major
rewrite of lots of APIs there's no way we can avoid the inode being
logged by something until after the AGI has been logged.
As we are going to be using ordered buffers for inode AIL tracking,
there isn't a need to actually lock that buffer against modification
as all the modifications are captured by logging the inode item
itself. Hence we don't actually need to join the cluster buffer into
the transaction until just before it is committed. This means we do
not perturb any of the existing buffer lock orders in transactions,
and the inode cluster buffer is always locked last in a transaction
that doesn't otherwise touch inode cluster buffers.
We do this by introducing a precommit log item method. This commit
just introduces the mechanism; the inode item implementation is in
followup commits.
The precommit items need to be sorted into consistent order as we
may be locking multiple items here. Hence if we have two dirty
inodes in cluster buffers A and B, and some other transaction has
two separate dirty inodes in the same cluster buffers, locking them
in different orders opens us up to ABBA deadlocks. Hence we sort the
items on the transaction based on the presence of a sort log item
method.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Combine the logging of the inode unlink list update into the
calling function that looks up the buffer we end up logging. These
do not need to be separate functions as they are both short, simple
operations and there's only a single call path through them. This
new function will end up being the core of the iunlink log item
processing...
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
We no longer need to have this function return the previous next
agino value from the on-disk inode as we have it in the in-core
inode now.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Guo Xuenan
Darrick J. Wong
Dave Chinner
Long Li
Jason A. Donenfeld
Lukas Herbolt
Allison Henderson
Li Zetao
Zeng Heng
Colin Ian King
Christian Brauner
Linus Torvalds
Shida Zhang
Lukas Czerner
Miklos Szeredi
Zhiqiang Liu
Gaosheng Cui
ye xingchen
Eric Biggers
Dan Williams
Peter Zijlstra
Al Viro
hexiaole
Chandan Babu R
Matthew Wilcox (Oracle)
Xie Shaowen
ChenXiaoSong
Shiyang Ruan
Stefan Roesch
Slark Xiao
Xin Gao
sunliming
Dan Carpenter
Xiaole He
Bart Van Assche