For whatever reason we never actually update pagi_count (the in-core
perag inode count) when we allocate or free inode chunks. Online scrub
is going to use it, so we need to fix the accounting.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
do_mod() is a hold-over from when we have different sizes for file
offsets and and other internal values for 40 bit XFS filesystems.
Hence depending on build flags variables passed to do_mod() could
change size. We no longer support those small format filesystems and
hence everything is of fixed size theses days, even on 32 bit
platforms.
As such, we can convert all the do_mod() callers to platform
optimised modulus operations as defined by linux/math64.h.
Individual conversions depend on the types of variables being used.
Signed-Off-By: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
xfs_attr3_leaf_create may have errored out before instantiating a buffer,
for example if the blkno is out of range. In that case there is no work
to do to remove it, and in fact xfs_da_shrink_inode will lead to an oops
if we try.
This also seems to fix a flaw where the original error from
xfs_attr3_leaf_create gets overwritten in the cleanup case, and it
removes a pointless assignment to bp which isn't used after this.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199969
Reported-by: Xu, Wen <wen.xu@gatech.edu>
Tested-by: Xu, Wen <wen.xu@gatech.edu>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Get rid of the MIN/MAX macros and just use the native min/max macros
directly in the XFS code.
Signed-Off-By: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
New verification functions like xfs_verify_fsbno() and
xfs_verify_agino() are spread across multiple files and different
header files. They really don't fit cleanly into the places they've
been put, and have wider scope than the current header includes.
Move the type verifiers to a new file in libxfs (xfs-types.c) and
the prototypes to xfs_types.h where they will be visible to all the
code that uses the types.
Signed-Off-By: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Remove the verbose license text from XFS files and replace them
with SPDX tags. This does not change the license of any of the code,
merely refers to the common, up-to-date license files in LICENSES/
This change was mostly scripted. fs/xfs/Makefile and
fs/xfs/libxfs/xfs_fs.h were modified by hand, the rest were detected
and modified by the following command:
for f in `git grep -l "GNU General" fs/xfs/` ; do
echo $f
cat $f | awk -f hdr.awk > $f.new
mv -f $f.new $f
done
And the hdr.awk script that did the modification (including
detecting the difference between GPL-2.0 and GPL-2.0+ licenses)
is as follows:
$ cat hdr.awk
BEGIN {
hdr = 1.0
tag = "GPL-2.0"
str = ""
}
/^ \* This program is free software/ {
hdr = 2.0;
next
}
/any later version./ {
tag = "GPL-2.0+"
next
}
/^ \*\// {
if (hdr > 0.0) {
print "// SPDX-License-Identifier: " tag
print str
print $0
str=""
hdr = 0.0
next
}
print $0
next
}
/^ \* / {
if (hdr > 1.0)
next
if (hdr > 0.0) {
if (str != "")
str = str "\n"
str = str $0
next
}
print $0
next
}
/^ \*/ {
if (hdr > 0.0)
next
print $0
next
}
// {
if (hdr > 0.0) {
if (str != "")
str = str "\n"
str = str $0
next
}
print $0
}
END { }
$
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
So we don't check the validity of records as we walk the btree. When
there are corrupt records in the free space btree (e.g. zero
startblock/length or beyond EOAG) we just blindly use it and things
go bad from there. That leads to assert failures on debug kernels
like this:
XFS: Assertion failed: fs_is_ok, file: fs/xfs/libxfs/xfs_alloc.c, line: 450
....
Call Trace:
xfs_alloc_fixup_trees+0x368/0x5c0
xfs_alloc_ag_vextent_near+0x79a/0xe20
xfs_alloc_ag_vextent+0x1d3/0x330
xfs_alloc_vextent+0x5e9/0x870
Or crashes like this:
XFS (loop0): xfs_buf_find: daddr 0x7fb28 out of range, EOFS 0x8000
.....
BUG: unable to handle kernel NULL pointer dereference at 00000000000000c8
....
Call Trace:
xfs_bmap_add_extent_hole_real+0x67d/0x930
xfs_bmapi_write+0x934/0xc90
xfs_da_grow_inode_int+0x27e/0x2f0
xfs_dir2_grow_inode+0x55/0x130
xfs_dir2_sf_to_block+0x94/0x5d0
xfs_dir2_sf_addname+0xd0/0x590
xfs_dir_createname+0x168/0x1a0
xfs_rename+0x658/0x9b0
By checking that free space records pulled from the trees are
within the valid range, we catch many of these corruptions before
they can do damage.
This is a generic btree record checking deficiency. We need to
validate the records we fetch from all the different btrees before
we use them to catch corruptions like this.
This patch results in a corrupt record emitting an error message and
returning -EFSCORRUPTED, and the higher layers catch that and abort:
XFS (loop0): Size Freespace BTree record corruption in AG 0 detected!
XFS (loop0): start block 0x0 block count 0x0
XFS (loop0): Internal error xfs_trans_cancel at line 1012 of file fs/xfs/xfs_trans.c. Caller xfs_create+0x42a/0x670
.....
Call Trace:
dump_stack+0x85/0xcb
xfs_trans_cancel+0x19f/0x1c0
xfs_create+0x42a/0x670
xfs_generic_create+0x1f6/0x2c0
vfs_create+0xf9/0x180
do_mknodat+0x1f9/0x210
do_syscall_64+0x5a/0x180
entry_SYSCALL_64_after_hwframe+0x49/0xbe
.....
XFS (loop0): xfs_do_force_shutdown(0x8) called from line 1013 of file fs/xfs/xfs_trans.c. Return address = ffffffff81500868
XFS (loop0): Corruption of in-memory data detected. Shutting down filesystem
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
In xfs_imap_to_bp(), we convert a -EFSCORRUPTED error to -EINVAL if
we are doing an untrusted lookup. This is done because we need
failed filehandle lookups to report -ESTALE to the caller, and it
does this by converting -EINVAL and -ENOENT errors to -ESTALE.
The squashing of EFSCORRUPTED in imap_to_bp makes it impossible for
for xfs_iget(UNTRUSTED) callers to determine the difference between
"inode does not exist" and "corruption detected during lookup". We
realy need that distinction in places calling xfS_iget(UNTRUSTED),
so move the filehandle error case handling all the way out to
xfs_nfs_get_inode() where it is needed.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
There are rules for vald extent size hints. We enforce them when
applications set them, but fuzzers violate those rules and that
screws us over. Validate COW extent size hint rules in the inode
verifier to catch this.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
There are rules for vald extent size hints. We enforce them when
applications set them, but fuzzers violate those rules and that
screws us over.
This results in alignment assertion failures when setting up
allocations such as this in direct IO:
XFS: Assertion failed: ap->length, file: fs/xfs/libxfs/xfs_bmap.c, line: 3432
....
Call Trace:
xfs_bmap_btalloc+0x415/0x910
xfs_bmapi_write+0x71c/0x12e0
xfs_iomap_write_direct+0x2a9/0x420
xfs_file_iomap_begin+0x4dc/0xa70
iomap_apply+0x43/0x100
iomap_file_buffered_write+0x62/0x90
xfs_file_buffered_aio_write+0xba/0x300
__vfs_write+0xd5/0x150
vfs_write+0xb6/0x180
ksys_write+0x45/0xa0
do_syscall_64+0x5a/0x180
entry_SYSCALL_64_after_hwframe+0x49/0xbe
And from xfs_db:
core.extsize = 10380288
Which is not an integer multiple of the block size, and so violates
Rule #7 for setting extent size hints. Validate extent size hint
rules in the inode verifier to catch this.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Use xfs_trans_getsb rather than reaching right in for
mp->m_sb_bp; I think this is more correct, and it facilitates
building this libxfs code in userspace as well.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Explicitly pass the buffer length to xfs_corruption_error() instead of
assuming XFS_CORRUPTION_DUMP_LEN so that we avoid dumping off the end
of the buffer.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Don't ASSERT when we encounter bad on-disk btree pointers in the debug
check functions. Log the error to leave breadcrumbs and let the upper
layers deal with it.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Instead of ASSERTing on null btree pointers in xfs_btree_ptr_to_daddr,
use the new block number verifiers to ensure that the btree pointer
doesn't point to any sensitive areas (AG headers, past-EOFS) and return
-EFSCORRUPTED if this is the case. Remove the ASSERT because on-disk
corruptions shouldn't trigger ASSERTs.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Make xfs_btree_check_ptr a non-debug function and introduce a new _debug
version that only runs when #ifdef DEBUG. This will enable us to reuse
the checking logic with other parts of the btree code.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Create a variant of xfs_dir2_data_freefind that is suitable for use in a
verifier. Because _freefind is called by the verifier, we simply
duplicate the _freefind function, convert the ASSERTs to return
__this_address, and modify the verifier to call our new function. Once
we've made it impossible for directory blocks with bad bestfree data to
make it into the filesystem we can remove the DEBUG code from the
regular _freefind function.
Underlying argument: corruption of on-disk metadata should return
-EFSCORRUPTED instead of blowing ASSERTs.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
If we're reading a node in a dir/attr btree and the buffer comes off the
disk with a magic number we don't recognize, don't ASSERT and don't set
a garbage buffer type (0 also triggers ASSERTs). Instead, report the
corruption, release the buffer, and return -EFSCORRUPTED because that's
what the dabtree is -- corrupt.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Don't ASSERT if the short form btree root pointer is zero. Now that we
use xfs_verify_agbno to check all short form btree pointers, we'll let
that log the error and pass it to the upper layers.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
If a btree lookup encounters an empty btree node or an empty btree leaf
on a multi-level btree, that's evidence of a corrupt on-disk btree.
Therefore, we should return -EFSCORRUPTED to the upper levels, not an
ASSERT failure.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Return -EFSCORRUPTED when the bnobt/cntbt return obviously corrupt
values, rather than letting them bounce around in the internal code.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
In xfs_dir2_leaf_addname we ASSERT if the length of the unused space
described by bestfree[0] is less the amount of space we wish to consume.
Immediately after it is a call to xfs_dir2_data_use_free where the
offset parameter is offset of the unused space and the length parameter
is the amount of space we wish to consume. Both values (and the unused
space pointer) are passed into xfs_dir2_data_check_free, which also
validates that the region of unused space is big enough to cover the
space we wish to consume. This is effectively the same check that the
ASSERT covers, and since a check failure results in a corruption message
being logged we can remove the ASSERT.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Don't bother ASSERTing when we're already going to log and return the
corruption status.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
The heads of tha AGI unlinked list are only scanned on debug
kernels when the verifier runs. Change that to always scan the heads
and validate that the inode numbers are valid.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
generic/475 fired an assert failure just after the filesystem was
shut down:
XFS: Assertion failed: fs_is_ok, file: fs/xfs/libxfs/xfs_refcount.c, line: 182
.....
Call Trace:
xfs_refcount_insert+0x151/0x190
xfs_refcount_adjust_extents.constprop.11+0x9c/0x470
xfs_refcount_adjust.constprop.10+0xb0/0x270
xfs_refcount_finish_one+0x25a/0x420
xfs_trans_log_finish_refcount_update+0x2a/0x40
xfs_refcount_update_finish_item+0x35/0xa0
xfs_defer_finish+0x15e/0x4d0
xfs_reflink_remap_extent+0x1bc/0x610
xfs_reflink_remap_blocks+0x6e/0x280
xfs_reflink_remap_range+0x311/0x530
vfs_clone_file_range+0x119/0x200
....
If xfs_btree_insert() returns an error, the corruption check fires
instead of passing the error back the caller. The corruption check
should be after we've checked for an error, not before, thereby
avoiding assert failures if the filesystem shuts down during a
refcount btree record insert.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
All the realtime allocation functions deal with space on the rtdev in
units of realtime extents. However, struct xfs_rtalloc_rec confusingly
uses the word 'block' in the name, even though they're really extents.
Fix the naming problem and fix all the unit handling problems in the two
existing users.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
Strengthen the rtalloc range query checks to make sure that the keys do
not run off the end of the realtime device inappropriately. Note that
the query range functions require units of rt extents, not blocks,
despite the type name.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
The xfs_rtbuf_get function should check the block mapping it gets back
from bmapi_read. If there are no mappings or the mapping isn't a real
extent, we should return -EFSCORRUPTED rather than trying to read a
garbage value. We also require realtime bitmap blocks to be real,
written allocations.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
xfs_rtword_t is used for bit manipulations in the realtime bitmap file.
Since we're performing bit shifts with this type, we don't want sign
extension and we don't want to be left shifting negative quantities
because that's undefined behavior.
This also shuts up these UBSAN warnings:
UBSAN: Undefined behaviour in fs/xfs/libxfs/xfs_rtbitmap.c:833:48
signed integer overflow:
-2147483648 - 1 cannot be represented in type 'int'
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
If one of the backup superblocks is found to differ seriously from
superblock 0, write out a fresh copy from the in-core sb.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
In commit a6a781a58b ("xfs: have buffer verifier functions
report failing address") the bad magic number return was ported
incorrectly.
Fixes: a6a781a58b
Reported-by: syzbot+08ab33be0178b76851c8@syzkaller.appspotmail.com
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
The GET ioctl is trivial, just return the current label.
The SET ioctl is more involved:
It transactionally modifies the superblock to write a new filesystem
label to the primary super.
A new variant of xfs_sync_sb then writes the superblock buffer
immediately to disk so that the change is visible from userspace.
It then invalidates any page cache that userspace might have previously
read on the block device so that i.e. blkid can see the change
immediately, and updates all secondary superblocks as userspace relable
does.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
[darrick: use dchinner's new xfs_update_secondary_sbs function]
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Growfs currently manually codes the extension of the last AG in a
filesytem during the growfs process. Factor that out of the growfs
code and move it into libxfs along with teh rest of the AG header
modification code.
Signed-Off-By: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
So it can be shared with userspace (e.g. mkfs) easily.
Signed-Off-By: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Plumb in the pieces necessary to make the "scrub" subfunction of
the scrub ioctl actually work. This means that we make the IFLAG_REPAIR
flag to the scrub ioctl actually do something, and we add an errortag
knob so that xfstests can force the kernel to rebuild a metadata
structure even if there's nothing wrong with it.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Teach xfs_bmapi_remap how to map in unwritten extent and to skip rmap
updates. This enables us to rebuild real and unwritten extents from the
rmapbt.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Add a new flags argument to xfs_bmapi_remapi so that we can pass BMAPI
flags into the function. This enables us to pass in BMAPI_ATTRFORK so
that we can remap things into the attribute fork. Eventually the
online repair code will use this to rebuild attribute forks, so make it
non-static.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
This function is basically a generic AGFL block iterator, so promote it
to libxfs ahead of online repair wanting to use it.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Secondary superblocks are rarely used, so create a helper to read a
given non-primary AG's superblock and ensure that it won't stick around
hogging memory.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
The changes to skip discards of speculative preallocation and
unwritten extents introduced several new wrapper functions through
the bunmapi -> extent free codepath to reduce churn in all of the
associated callers. In several cases, these wrappers simply toggle a
single flag to skip or not skip discards for the resulting blocks.
The explicit _nodiscard() wrappers for such an isolated set of
callers is a bit overkill. Kill off these wrappers and replace with
the calls to the underlying functions in the contexts that need to
control discard behavior. Retain the wrappers that preserve the
original calling conventions to serve the original purpose of
reducing code churn.
This is a refactoring patch and does not change behavior.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Add a new flag, XFS_BMAPI_NORMAP, which will perform file block
remapping without updating the rmapbt. This will be used by the repair
code to reconstruct bmbts from the rmapbt, in which case we don't want
the rmapbt update.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Add a couple of functions to the refcount btree and generic btree code
that will be used to repair the refcountbt.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Add a couple of functions to the reverse mapping btree that will be used
to repair the rmapbt.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Expose various helpers that the repair code will want to use.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Add a bunch of helper functions that calculate the sizes of various
btrees. These will be used to repair btrees and btree headers.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
DQALLOC is only ever used with xfs_qm_dqget*, and the only flag that the
_dqget family of functions cares about is DQALLOC. Therefore, change
it to a boolean 'can alloc?' flag for the dqget interfaces where that
makes sense.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
The flags argument is always zero, get rid of it.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
There's only one caller of DQNEXT and its semantics can be moved into a
separate function, so create the function and get rid of the flag.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Unwritten extents by definition have not been written to until they
are converted to normal written extents. If unwritten extents are
freed from a file, it is therefore guaranteed that the blocks have
not been written to since allocation (note that zero range punches
and reallocates blocks).
To cut down on online discards generated from workloads that make
use of preallocation, skip discards of extents if they are in the
unwritten state when the extent is freed.
Note that this optimization does not apply to log recovery, during
which all freed extents are discarded if online discard is enabled.
Also note that it may be possible for a filesystem crash to occur
after write completion of an unwritten extent but before unwritten
conversion such that the extent remains unwritten after log
recovery. Since this pseudo-inconsistency may already be possible
after a crash (consider writing to recently allocated blocks where
the allocation transaction is lost after a crash), this change
shouldn't introduce any fundamental limitations that don't already
exist. In short, on storage stacks where discards are important,
it's good practice to run an occasional fstrim even with online
discard enabled in the filesystem, particularly after a crash.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Freed extents are unconditionally discarded when online discard is
enabled. Define XFS_BMAPI_NODISCARD to allow callers to bypass
discards when unnecessary. For example, this will be useful for
eofblocks trimming.
This patch does not change behavior.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Darrick J. Wong
Dave Chinner
Eric Sandeen
Eric Sandeen
Brian Foster