On umount path, jbd2_journal_destroy() writes latest transaction ID
(->j_tail_sequence) to be used at next mount.
The bug is that ->j_tail_sequence is not holding latest transaction ID
in some cases. So, at next mount, there is chance to conflict with
remaining (not overwritten yet) transactions.
mount (id=10)
write transaction (id=11)
write transaction (id=12)
umount (id=10) <= the bug doesn't write latest ID
mount (id=10)
write transaction (id=11)
crash
mount
[recovery process]
transaction (id=11)
transaction (id=12) <= valid transaction ID, but old commit
must not replay
Like above, this bug become the cause of recovery failure, or FS
corruption.
So why ->j_tail_sequence doesn't point latest ID?
Because if checkpoint transactions was reclaimed by memory pressure
(i.e. bdev_try_to_free_page()), then ->j_tail_sequence is not updated.
(And another case is, __jbd2_journal_clean_checkpoint_list() is called
with empty transaction.)
So in above cases, ->j_tail_sequence is not pointing latest
transaction ID at umount path. Plus, REQ_FLUSH for checkpoint is not
done too.
So, to fix this problem with minimum changes, this patch updates
->j_tail_sequence, and issue REQ_FLUSH. (With more complex changes,
some optimizations would be possible to avoid unnecessary REQ_FLUSH
for example though.)
BTW,
journal->j_tail_sequence =
++journal->j_transaction_sequence;
Increment of ->j_transaction_sequence seems to be unnecessary, but
ext3 does this.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Currently we used atomic bit operations to manipulate
__JI_COMMIT_RUNNING bit. However this is unnecessary as i_flags are
always written and read under j_list_lock. So just change the operations
to standard bit operations.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Revoke and tag descriptor blocks are just different kinds of descriptor
blocks and thus have checksum in the same place. Unify computation and
checking of checksums for these.
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Descriptor block header is initialized in several places. Factor out the
common code into jbd2_journal_get_descriptor_buffer().
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
jbd2_journal_write_revoke_records() takes journal pointer and write_op,
although journal can be obtained from the passed transaction and
write_op is always WRITE_SYNC. Remove these superfluous arguments.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
some endian conversion problems with ext4 encryption, potential memory
leaks after truncate in data=journal mode, and an ocfs2 regression
caused by a jbd2 performance improvement.
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Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 fixes from Ted Ts'o:
"Ext4 bug fixes for v4.4, including fixes for post-2038 time encodings,
some endian conversion problems with ext4 encryption, potential memory
leaks after truncate in data=journal mode, and an ocfs2 regression
caused by a jbd2 performance improvement"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
jbd2: fix null committed data return in undo_access
ext4: add "static" to ext4_seq_##name##_fops struct
ext4: fix an endianness bug in ext4_encrypted_follow_link()
ext4: fix an endianness bug in ext4_encrypted_zeroout()
jbd2: Fix unreclaimed pages after truncate in data=journal mode
ext4: Fix handling of extended tv_sec
Ted and Namjae have reported that truncated pages don't get timely
reclaimed after being truncated in data=journal mode. The following test
triggers the issue easily:
for (i = 0; i < 1000; i++) {
pwrite(fd, buf, 1024*1024, 0);
fsync(fd);
fsync(fd);
ftruncate(fd, 0);
}
The reason is that journal_unmap_buffer() finds that truncated buffers
are not journalled (jh->b_transaction == NULL), they are part of
checkpoint list of a transaction (jh->b_cp_transaction != NULL) and have
been already written out (!buffer_dirty(bh)). We clean such buffers but
we leave them in the checkpoint list. Since checkpoint transaction holds
a reference to the journal head, these buffers cannot be released until
the checkpoint transaction is cleaned up. And at that point we don't
call release_buffer_page() anymore so pages detached from mapping are
lingering in the system waiting for reclaim to find them and free them.
Fix the problem by removing buffers from transaction checkpoint lists
when journal_unmap_buffer() finds out they don't have to be there
anymore.
Reported-and-tested-by: Namjae Jeon <namjae.jeon@samsung.com>
Fixes: de1b794130
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Merge second patch-bomb from Andrew Morton:
- most of the rest of MM
- procfs
- lib/ updates
- printk updates
- bitops infrastructure tweaks
- checkpatch updates
- nilfs2 update
- signals
- various other misc bits: coredump, seqfile, kexec, pidns, zlib, ipc,
dma-debug, dma-mapping, ...
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (102 commits)
ipc,msg: drop dst nil validation in copy_msg
include/linux/zutil.h: fix usage example of zlib_adler32()
panic: release stale console lock to always get the logbuf printed out
dma-debug: check nents in dma_sync_sg*
dma-mapping: tidy up dma_parms default handling
pidns: fix set/getpriority and ioprio_set/get in PRIO_USER mode
kexec: use file name as the output message prefix
fs, seqfile: always allow oom killer
seq_file: reuse string_escape_str()
fs/seq_file: use seq_* helpers in seq_hex_dump()
coredump: change zap_threads() and zap_process() to use for_each_thread()
coredump: ensure all coredumping tasks have SIGNAL_GROUP_COREDUMP
signal: remove jffs2_garbage_collect_thread()->allow_signal(SIGCONT)
signal: introduce kernel_signal_stop() to fix jffs2_garbage_collect_thread()
signal: turn dequeue_signal_lock() into kernel_dequeue_signal()
signals: kill block_all_signals() and unblock_all_signals()
nilfs2: fix gcc uninitialized-variable warnings in powerpc build
nilfs2: fix gcc unused-but-set-variable warnings
MAINTAINERS: nilfs2: add header file for tracing
nilfs2: add tracepoints for analyzing reading and writing metadata files
...
__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts. They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve". __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".
Over time, callers had a requirement to not block when fallback options
were available. Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.
This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative. High priority users continue to use
__GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim. __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.
This patch then converts a number of sites
o __GFP_ATOMIC is used by callers that are high priority and have memory
pools for those requests. GFP_ATOMIC uses this flag.
o Callers that have a limited mempool to guarantee forward progress clear
__GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
into this category where kswapd will still be woken but atomic reserves
are not used as there is a one-entry mempool to guarantee progress.
o Callers that are checking if they are non-blocking should use the
helper gfpflags_allow_blocking() where possible. This is because
checking for __GFP_WAIT as was done historically now can trigger false
positives. Some exceptions like dm-crypt.c exist where the code intent
is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
flag manipulations.
o Callers that built their own GFP flags instead of starting with GFP_KERNEL
and friends now also need to specify __GFP_KSWAPD_RECLAIM.
The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.
The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL. They may
now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If a EXT4 filesystem utilizes JBD2 journaling and an error occurs, the
journaling will be aborted first and the error number will be recorded
into JBD2 superblock and, finally, the system will enter into the
panic state in "errors=panic" option. But, in the rare case, this
sequence is little twisted like the below figure and it will happen
that the system enters into panic state, which means the system reset
in mobile environment, before completion of recording an error in the
journal superblock. In this case, e2fsck cannot recognize that the
filesystem failure occurred in the previous run and the corruption
wouldn't be fixed.
Task A Task B
ext4_handle_error()
-> jbd2_journal_abort()
-> __journal_abort_soft()
-> __jbd2_journal_abort_hard()
| -> journal->j_flags |= JBD2_ABORT;
|
| __ext4_abort()
| -> jbd2_journal_abort()
| | -> __journal_abort_soft()
| | -> if (journal->j_flags & JBD2_ABORT)
| | return;
| -> panic()
|
-> jbd2_journal_update_sb_errno()
Tested-by: Hobin Woo <hobin.woo@samsung.com>
Signed-off-by: Daeho Jeong <daeho.jeong@samsung.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Unlike comments and expectation of callers journal_clean_one_cp_list()
returned 1 not only if it freed the transaction but also if it freed
some buffers in the transaction. That could make
__jbd2_journal_clean_checkpoint_list() skip processing
t_checkpoint_io_list and continue with processing the next transaction.
This is mostly a cosmetic issue since the only result is we can
sometimes free less memory than we could. But it's still worth fixing.
Fix journal_clean_one_cp_list() to return 1 only if the transaction was
really freed.
Fixes: 50849db32a
Signed-off-by: Jan Kara <jack@suse.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Create separate predicate functions to test/set/clear feature flags,
thereby replacing the wordy old macros. Furthermore, clean out the
places where we open-coded feature tests.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Instead of overloading EIO for CRC errors and corrupt structures,
return the same error codes that XFS returns for the same issues.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Change the journal's checksum functions to gate on whether or not the
crc32c driver is loaded, and gate the loading on the superblock bits.
This prevents a journal crash if someone loads a journal in no-csum
mode and then randomizes the superblock, thus flipping on the feature
bits.
Tested-By: Nikolay Borisov <kernel@kyup.com>
Reported-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Currently there is no limitation on number of reserved credits we can
ask for. If we ask for more reserved credits than 1/2 of maximum
transaction size, or if total number of credits exceeds the maximum
transaction size per operation (which is currently only possible with
the former) we will spin forever in start_this_handle().
Fix this by adding this limitation at the start of start_this_handle().
This patch also removes the credit limitation 1/2 of maximum transaction
size, since we really only want to limit the number of reserved credits.
There is not much point to limit the credits if there is still space in
the journal.
This accidentally also fixes the online resize, where due to the
limitation of the journal credits we're unable to grow file systems with
1k block size and size between 16M and 32M. It has been partially fixed
by 2c869b262a, but not entirely.
Thanks Jan Kara for helping me getting the correct fix.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Commit 6f6a6fda29 "jbd2: fix ocfs2 corrupt when updating journal
superblock fails" changed jbd2_cleanup_journal_tail() to return EIO
when the journal is aborted. That makes logic in
jbd2_log_do_checkpoint() bail out which is fine, except that
jbd2_journal_destroy() expects jbd2_log_do_checkpoint() to always make
a progress in cleaning the journal. Without it jbd2_journal_destroy()
just loops in an infinite loop.
Fix jbd2_journal_destroy() to cleanup journal checkpoint lists of
jbd2_log_do_checkpoint() fails with error.
Reported-by: Eryu Guan <guaneryu@gmail.com>
Tested-by: Eryu Guan <guaneryu@gmail.com>
Fixes: 6f6a6fda29
Signed-off-by: Jan Kara <jack@suse.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When an error condition is detected, an error status should be recorded into
superblocks of EXT4 or JBD2. However, the write request is submitted now
without REQ_FUA flag, even in "barrier=1" mode, which is followed by
panic() function in "errors=panic" mode. On mobile devices which make
whole system reset as soon as kernel panic occurs, this write request
containing an error flag will disappear just from storage cache without
written to the physical cells. Therefore, when next start, even forever,
the error flag cannot be shown in both superblocks, and e2fsck cannot fix
the filesystem problems automatically, unless e2fsck is executed in
force checking mode.
[ Changed use test_opt(sb, BARRIER) of checking the journal flags -- TYT ]
Signed-off-by: Daeho Jeong <daeho.jeong@samsung.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
It is often the case that we mark buffer as having dirty metadata when
the buffer is already in that state (frequent for bitmaps, inode table
blocks, superblock). Thus it is unnecessary to contend on grabbing
journal head reference and bh_state lock. Avoid that by checking whether
any modification to the buffer is needed before grabbing any locks or
references.
[ Note: this is a fixed version of commit 2143c1965a, which was
reverted in ebeaa8ddb3 due to a false positive triggering of an
assertion check. -- Ted ]
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This reverts commit 2143c1965a.
This commit seems to be the cause of the following jbd2 assertion
failure:
------------[ cut here ]------------
kernel BUG at fs/jbd2/transaction.c:1325!
invalid opcode: 0000 [#1] SMP
Modules linked in: bnep bluetooth fuse ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 ...
CPU: 7 PID: 5509 Comm: gcc Not tainted 4.1.0-10944-g2a298679b411 #1
Hardware name: /DH87RL, BIOS RLH8710H.86A.0327.2014.0924.1645 09/24/2014
task: ffff8803bf866040 ti: ffff880308528000 task.ti: ffff880308528000
RIP: jbd2_journal_dirty_metadata+0x237/0x290
Call Trace:
__ext4_handle_dirty_metadata+0x43/0x1f0
ext4_handle_dirty_dirent_node+0xde/0x160
? jbd2_journal_get_write_access+0x36/0x50
ext4_delete_entry+0x112/0x160
? __ext4_journal_start_sb+0x52/0xb0
ext4_unlink+0xfa/0x260
vfs_unlink+0xec/0x190
do_unlinkat+0x24a/0x270
SyS_unlink+0x11/0x20
entry_SYSCALL_64_fastpath+0x12/0x6a
---[ end trace ae033ebde8d080b4 ]---
which is not easily reproducible (I've seen it just once, and then Ted
was able to reproduce it once). Revert it while Ted and Jan try to
figure out what is wrong.
Cc: Jan Kara <jack@suse.cz>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge second patchbomb from Andrew Morton:
- most of the rest of MM
- lots of misc things
- procfs updates
- printk feature work
- updates to get_maintainer, MAINTAINERS, checkpatch
- lib/ updates
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (96 commits)
exit,stats: /* obey this comment */
coredump: add __printf attribute to cn_*printf functions
coredump: use from_kuid/kgid when formatting corename
fs/reiserfs: remove unneeded cast
NILFS2: support NFSv2 export
fs/befs/btree.c: remove unneeded initializations
fs/minix: remove unneeded cast
init/do_mounts.c: add create_dev() failure log
kasan: remove duplicate definition of the macro KASAN_FREE_PAGE
fs/efs: femove unneeded cast
checkpatch: emit "NOTE: <types>" message only once after multiple files
checkpatch: emit an error when there's a diff in a changelog
checkpatch: validate MODULE_LICENSE content
checkpatch: add multi-line handling for PREFER_ETHER_ADDR_COPY
checkpatch: suggest using eth_zero_addr() and eth_broadcast_addr()
checkpatch: fix processing of MEMSET issues
checkpatch: suggest using ether_addr_equal*()
checkpatch: avoid NOT_UNIFIED_DIFF errors on cover-letter.patch files
checkpatch: remove local from codespell path
checkpatch: add --showfile to allow input via pipe to show filenames
...
In one case, we eliminate a local variable; in the other a strlen()
call and some .text.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is often the case that we mark buffer as having dirty metadata when
the buffer is already in that state (frequent for bitmaps, inode table
blocks, superblock). Thus it is unnecessary to contend on grabbing
journal head reference and bh_state lock. Avoid that by checking whether
any modification to the buffer is needed before grabbing any locks or
references.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
insert_revoke_hash does an open coded endless allocation loop if
journal_oom_retry is true. It doesn't implement any allocation fallback
strategy between the retries, though. The memory allocator doesn't know
about the never fail requirement so it cannot potentially help to move
on with the allocation (e.g. use memory reserves).
Get rid of the retry loop and use __GFP_NOFAIL instead. We will lose the
debugging message but I am not sure it is anyhow helpful.
Do the same for journal_alloc_journal_head which is doing a similar
thing.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
If updating journal superblock fails after journal data has been
flushed, the error is omitted and this will mislead the caller as a
normal case. In ocfs2, the checkpoint will be treated successfully
and the other node can get the lock to update. Since the sb_start is
still pointing to the old log block, it will rewrite the journal data
during journal recovery by the other node. Thus the new updates will
be overwritten and ocfs2 corrupts. So in above case we have to return
the error, and ocfs2_commit_cache will take care of the error and
prevent the other node to do update first. And only after recovering
journal it can do the new updates.
The issue discussion mail can be found at:
https://oss.oracle.com/pipermail/ocfs2-devel/2015-June/010856.htmlhttp://comments.gmane.org/gmane.comp.file-systems.ext4/48841
[ Fixed bug in patch which allowed a non-negative error return from
jbd2_cleanup_journal_tail() to leak out of jbd2_fjournal_flush(); this
was causing xfstests ext4/306 to fail. -- Ted ]
Reported-by: Yiwen Jiang <jiangyiwen@huawei.com>
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Tested-by: Yiwen Jiang <jiangyiwen@huawei.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: stable@vger.kernel.org
jbd2_journal_get_write_access() and jbd2_journal_get_create_access() are
frequently called for buffers that are already part of the running
transaction - most frequently it is the case for bitmaps, inode table
blocks, and superblock. Since in such cases we have nothing to do, it is
unfortunate we still grab reference to journal head, lock the bh, lock
bh_state only to find out there's nothing to do.
Improving this is a bit subtle though since until we find out journal
head is attached to the running transaction, it can disappear from under
us because checkpointing / commit decided it's no longer needed. We deal
with this by protecting journal_head slab with RCU. We still have to be
careful about journal head being freed & reallocated within slab and
about exposing journal head in consistent state (in particular
b_modified and b_frozen_data must be in correct state before we allow
user to touch the buffer).
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Check for the simple case of unjournaled buffer first, handle it and
bail out. This allows us to remove one if and unindent the difficult case
by one tab. The result is easier to read.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
We were acquiring bh_state_lock when allocation of buffer failed in
do_get_write_access() only to be able to jump to a label that releases
the lock and does all other checks that don't make sense for this error
path. Just jump into the right label instead.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
needs_copy is set only in one place in do_get_write_access(), just move
the frozen buffer copying into that place and factor it out to a
separate function to make do_get_write_access() slightly more readable.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This basically reverts 47def82672 (jbd2: Remove __GFP_NOFAIL from jbd2
layer). The deprecation of __GFP_NOFAIL was a bad choice because it led
to open coding the endless loop around the allocator rather than
removing the dependency on the non failing allocation. So the
deprecation was a clear failure and the reality tells us that
__GFP_NOFAIL is not even close to go away.
It is still true that __GFP_NOFAIL allocations are generally discouraged
and new uses should be evaluated and an alternative (pre-allocations or
reservations) should be considered but it doesn't make any sense to lie
the allocator about the requirements. Allocator can take steps to help
making a progress if it knows the requirements.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: David Rientjes <rientjes@google.com>
The journal revoke block recovery code does not check r_count for
sanity, which means that an evil value of r_count could result in
the kernel reading off the end of the revoke table and into whatever
garbage lies beyond. This could crash the kernel, so fix that.
However, in testing this fix, I discovered that the code to write
out the revoke tables also was not correctly checking to see if the
block was full -- the current offset check is fine so long as the
revoke table space size is a multiple of the record size, but this
is not true when either journal_csum_v[23] are set.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@vger.kernel.org
Currently when journal restart fails, we'll have the h_transaction of
the handle set to NULL to indicate that the handle has been effectively
aborted. We handle this situation quietly in the jbd2_journal_stop() and just
free the handle and exit because everything else has been done before we
attempted (and failed) to restart the journal.
Unfortunately there are a number of problems with that approach
introduced with commit
41a5b91319 "jbd2: invalidate handle if jbd2_journal_restart()
fails"
First of all in ext4 jbd2_journal_stop() will be called through
__ext4_journal_stop() where we would try to get a hold of the superblock
by dereferencing h_transaction which in this case would lead to NULL
pointer dereference and crash.
In addition we're going to free the handle regardless of the refcount
which is bad as well, because others up the call chain will still
reference the handle so we might potentially reference already freed
memory.
Moreover it's expected that we'll get aborted handle as well as detached
handle in some of the journalling function as the error propagates up
the stack, so it's unnecessary to call WARN_ON every time we get
detached handle.
And finally we might leak some memory by forgetting to free reserved
handle in jbd2_journal_stop() in the case where handle was detached from
the transaction (h_transaction is NULL).
Fix the NULL pointer dereference in __ext4_journal_stop() by just
calling jbd2_journal_stop() quietly as suggested by Jan Kara. Also fix
the potential memory leak in jbd2_journal_stop() and use proper
handle refcounting before we attempt to free it to avoid use-after-free
issues.
And finally remove all WARN_ON(!transaction) from the code so that we do
not get random traces when something goes wrong because when journal
restart fails we will get to some of those functions.
Cc: stable@vger.kernel.org
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
We should complain in dmesg when journal recovery fails on account of
the descriptor block being corrupt, so that the diagnostic data can
be recovered.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
fixes, which should improve CPU utilization and potential soft lockups
under heavy memory pressure, and Eric Whitney's bigalloc fixes.
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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:
"Lots of bugs fixes, including Zheng and Jan's extent status shrinker
fixes, which should improve CPU utilization and potential soft lockups
under heavy memory pressure, and Eric Whitney's bigalloc fixes"
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (26 commits)
ext4: ext4_da_convert_inline_data_to_extent drop locked page after error
ext4: fix suboptimal seek_{data,hole} extents traversial
ext4: ext4_inline_data_fiemap should respect callers argument
ext4: prevent fsreentrance deadlock for inline_data
ext4: forbid journal_async_commit in data=ordered mode
jbd2: remove unnecessary NULL check before iput()
ext4: Remove an unnecessary check for NULL before iput()
ext4: remove unneeded code in ext4_unlink
ext4: don't count external journal blocks as overhead
ext4: remove never taken branch from ext4_ext_shift_path_extents()
ext4: create nojournal_checksum mount option
ext4: update comments regarding ext4_delete_inode()
ext4: cleanup GFP flags inside resize path
ext4: introduce aging to extent status tree
ext4: cleanup flag definitions for extent status tree
ext4: limit number of scanned extents in status tree shrinker
ext4: move handling of list of shrinkable inodes into extent status code
ext4: change LRU to round-robin in extent status tree shrinker
ext4: cache extent hole in extent status tree for ext4_da_map_blocks()
ext4: fix block reservation for bigalloc filesystems
...
When we're enabling journal features, we cannot use the predicate
jbd2_journal_has_csum_v2or3() because we haven't yet set the sb
feature flag fields! Moreover, we just finished loading the shash
driver, so the test is unnecessary; calculate the seed always.
Without this patch, we fail to initialize the checksum seed the first
time we turn on journal_checksum, which means that all journal blocks
written during that first mount are corrupt. Transactions written
after the second mount will be fine, since the feature flag will be
set in the journal superblock. xfstests generic/{034,321,322} are the
regression tests.
(This is important for 3.18.)
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.coM>
Reported-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The old hash function didn't work well for 64-bit block numbers, and
used undefined (negative) shift right behavior. Use the generic
64-bit hash function instead.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reported-by: Andrey Ryabinin <a.ryabinin@samsung.com>
__jbd2_journal_clean_checkpoint_list() returns number of buffers it
freed but noone was using the value so just stop doing that. This
also allows for simplifying the calling convention for
journal_clean_once_cp_list().
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Yuanhan has reported that when he is running fsync(2) heavy workload
creating new files over ramdisk, significant amount of time is spent in
__jbd2_journal_clean_checkpoint_list() trying to clean old transactions
(but they cannot be cleaned up because flusher hasn't yet checkpointed
those buffers). The workload can be generated by:
fs_mark -d /fs/ram0/1 -D 2 -N 2560 -n 1000000 -L 1 -S 1 -s 4096
Reduce the amount of scanning by stopping to scan the transaction list
once we find a transaction that cannot be checkpointed. Note that this
way of cleaning is still enough to keep freeing space in the journal
after fully checkpointed transactions.
Reported-and-tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
If EIO happens after we have dropped j_state_lock, we won't notice
that the journal has been aborted. So it is reasonable to move this
check after we have grabbed the j_checkpoint_mutex and re-grabbed the
j_state_lock. This patch helps to prevent false positive complain
after EIO.
#DMESG:
__jbd2_log_wait_for_space: needed 8448 blocks and only had 8386 space available
__jbd2_log_wait_for_space: no way to get more journal space in ram1-8
------------[ cut here ]------------
WARNING: CPU: 15 PID: 6739 at fs/jbd2/checkpoint.c:168 __jbd2_log_wait_for_space+0x188/0x200()
Modules linked in: brd iTCO_wdt lpc_ich mfd_core igb ptp dm_mirror dm_region_hash dm_log dm_mod
CPU: 15 PID: 6739 Comm: fsstress Tainted: G W 3.17.0-rc2-00429-g684de57 #139
Hardware name: Intel Corporation W2600CR/W2600CR, BIOS SE5C600.86B.99.99.x028.061320111235 06/13/2011
00000000000000a8 ffff88077aaab878 ffffffff815c1a8c 00000000000000a8
0000000000000000 ffff88077aaab8b8 ffffffff8106ce8c ffff88077aaab898
ffff8807c57e6000 ffff8807c57e6028 0000000000002100 ffff8807c57e62f0
Call Trace:
[<ffffffff815c1a8c>] dump_stack+0x51/0x6d
[<ffffffff8106ce8c>] warn_slowpath_common+0x8c/0xc0
[<ffffffff8106ceda>] warn_slowpath_null+0x1a/0x20
[<ffffffff812419f8>] __jbd2_log_wait_for_space+0x188/0x200
[<ffffffff8123be9a>] start_this_handle+0x4da/0x7b0
[<ffffffff810990e5>] ? local_clock+0x25/0x30
[<ffffffff810aba87>] ? lockdep_init_map+0xe7/0x180
[<ffffffff8123c5bc>] jbd2__journal_start+0xdc/0x1d0
[<ffffffff811f2414>] ? __ext4_new_inode+0x7f4/0x1330
[<ffffffff81222a38>] __ext4_journal_start_sb+0xf8/0x110
[<ffffffff811f2414>] __ext4_new_inode+0x7f4/0x1330
[<ffffffff810ac359>] ? lock_release_holdtime+0x29/0x190
[<ffffffff812025bb>] ext4_create+0x8b/0x150
[<ffffffff8117fe3b>] vfs_create+0x7b/0xb0
[<ffffffff8118097b>] do_last+0x7db/0xcf0
[<ffffffff8117e31d>] ? inode_permission+0x4d/0x50
[<ffffffff811845d2>] path_openat+0x242/0x590
[<ffffffff81191a76>] ? __alloc_fd+0x36/0x140
[<ffffffff81184a6a>] do_filp_open+0x4a/0xb0
[<ffffffff81191b61>] ? __alloc_fd+0x121/0x140
[<ffffffff81172f20>] do_sys_open+0x170/0x220
[<ffffffff8117300e>] SyS_open+0x1e/0x20
[<ffffffff811715d6>] SyS_creat+0x16/0x20
[<ffffffff815c7e12>] system_call_fastpath+0x16/0x1b
---[ end trace cd71c831f82059db ]---
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Free the buffer head if the journal descriptor block fails checksum
verification.
This is the jbd2 port of the e2fsprogs patch "e2fsck: free bh on csum
verify error in do_one_pass".
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Cc: stable@vger.kernel.org
Clear all three journal checksum feature flags before turning on
whichever journal checksum options we want. Rearrange the error
checking so that newer flags get complained about first.
Reported-by: TR Reardon <thomas_reardon@hotmail.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Sicne the jbd/jbd2 superblock is not released until the file system is
unmounted, allocate the buffer cache from the non-moveable area to
allow page migration and CMA allocations to more easily succeed.
Signed-off-by: Gioh Kim <gioh.kim@lge.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
When we discover written out buffer in transaction checkpoint list we
don't have to recheck validity of a transaction. Either this is the
last buffer in a transaction - and then we are done - or this isn't
and then we can just take another buffer from the checkpoint list
without dropping j_list_lock.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The __jbd2_journal_remove_checkpoint() doesn't require an elevated
b_count; indeed, until the jh structure gets released by the call to
jbd2_journal_put_journal_head(), the bh's b_count is elevated by
virtue of the existence of the jh structure.
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
__wait_cp_io() is only called by jbd2_log_do_checkpoint(). Fold it in
to make it a bit easier to understand.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
__process_buffer() is only called by jbd2_log_do_checkpoint(), and it
had a very complex locking protocol where it would be called with the
j_list_lock, and sometimes exit with the lock held (if the return code
was 0), or release the lock.
This was confusing both to humans and to smatch (which erronously
complained that the lock was taken twice).
Folding __process_buffer() to the caller allows us to simplify the
control flow, making the resulting function easier to read and reason
about, and dropping the compiled size of fs/jbd2/checkpoint.c by 150
bytes (over 4% of the text size).
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
It turns out that there are some serious problems with the on-disk
format of journal checksum v2. The foremost is that the function to
calculate descriptor tag size returns sizes that are too big. This
causes alignment issues on some architectures and is compounded by the
fact that some parts of jbd2 use the structure size (incorrectly) to
determine the presence of a 64bit journal instead of checking the
feature flags.
Therefore, introduce journal checksum v3, which enlarges the
descriptor block tag format to allow for full 32-bit checksums of
journal blocks, fix the journal tag function to return the correct
sizes, and fix the jbd2 recovery code to use feature flags to
determine 64bitness.
Add a few function helpers so we don't have to open-code quite so
many pieces.
Switching to a 16-byte block size was found to increase journal size
overhead by a maximum of 0.1%, to convert a 32-bit journal with no
checksumming to a 32-bit journal with checksum v3 enabled.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reported-by: TR Reardon <thomas_reardon@hotmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
When recovering the journal, don't fall into an infinite loop if we
encounter a corrupt journal block. Instead, just skip the block and
return an error, which fails the mount and thus forces the user to run
a full filesystem fsck.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
The current "wait_on_bit" interface requires an 'action'
function to be provided which does the actual waiting.
There are over 20 such functions, many of them identical.
Most cases can be satisfied by one of just two functions, one
which uses io_schedule() and one which just uses schedule().
So:
Rename wait_on_bit and wait_on_bit_lock to
wait_on_bit_action and wait_on_bit_lock_action
to make it explicit that they need an action function.
Introduce new wait_on_bit{,_lock} and wait_on_bit{,_lock}_io
which are *not* given an action function but implicitly use
a standard one.
The decision to error-out if a signal is pending is now made
based on the 'mode' argument rather than being encoded in the action
function.
All instances of the old wait_on_bit and wait_on_bit_lock which
can use the new version have been changed accordingly and their
action functions have been discarded.
wait_on_bit{_lock} does not return any specific error code in the
event of a signal so the caller must check for non-zero and
interpolate their own error code as appropriate.
The wait_on_bit() call in __fscache_wait_on_invalidate() was
ambiguous as it specified TASK_UNINTERRUPTIBLE but used
fscache_wait_bit_interruptible as an action function.
David Howells confirms this should be uniformly
"uninterruptible"
The main remaining user of wait_on_bit{,_lock}_action is NFS
which needs to use a freezer-aware schedule() call.
A comment in fs/gfs2/glock.c notes that having multiple 'action'
functions is useful as they display differently in the 'wchan'
field of 'ps'. (and /proc/$PID/wchan).
As the new bit_wait{,_io} functions are tagged "__sched", they
will not show up at all, but something higher in the stack. So
the distinction will still be visible, only with different
function names (gds2_glock_wait versus gfs2_glock_dq_wait in the
gfs2/glock.c case).
Since first version of this patch (against 3.15) two new action
functions appeared, on in NFS and one in CIFS. CIFS also now
uses an action function that makes the same freezer aware
schedule call as NFS.
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: David Howells <dhowells@redhat.com> (fscache, keys)
Acked-by: Steven Whitehouse <swhiteho@redhat.com> (gfs2)
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steve French <sfrench@samba.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140707051603.28027.72349.stgit@notabene.brown
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The mount manpage says of the max_batch_time option,
This optimization can be turned off entirely
by setting max_batch_time to 0.
But the code doesn't do that. So fix the code to do
that.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Fix up error messages printed when the transaction pointers in a
journal head are inconsistent. This improves the error messages which
are printed when running xfstests generic/068 in data=journal mode.
See the bug report at: https://bugzilla.kernel.org/show_bug.cgi?id=60786
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
It's not needed until we start trying to modifying fields in the
journal_head which are protected by j_list_lock.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
It's not needed until we start trying to modifying fields in the
journal_head which are protected by j_list_lock.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
jh->b_transaction is adequately protected for reading by the
jbd_lock_bh_state(bh), so we don't need to take j_list_lock in
__journal_try_to_free_buffer().
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
We don't otherwise need j_list_lock during the rest of commit phase
#7, so add the transaction to the checkpoint list at the very end of
commit phase #6. This allows us to drop j_list_lock earlier, which is
a good thing since it is a super hot lock.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The two hottest locks, and thus the biggest scalability bottlenecks,
in the jbd2 layer, are the j_list_lock and j_state_lock. This has
inspired some people to do some truly unnatural things[1].
[1] https://www.usenix.org/system/files/conference/fast14/fast14-paper_kang.pdf
We don't need to be holding both j_state_lock and j_list_lock while
calculating the journal statistics, so move those calculations to the
very end of jbd2_journal_commit_transaction.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The j_state_lock is one of the hottest locks in the jbd2 layer and
thus one of its scalability bottlenecks.
We don't need to be holding the j_state_lock while we are calling
wake_up(&journal->j_wait_commit), so release the lock a little bit
earlier.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
During commit process, keep the block device plugged after we are done
writing the revoke records, until we are finished writing the rest of
the commit records in the journal. This will allow most of the
journal blocks to be written in a single I/O operation, instead of
separating the the revoke blocks from the rest of the journal blocks.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Mark functions as static in jbd2/journal.c because they are not used
outside this file.
This eliminates the following warning in jbd2/journal.c:
fs/jbd2/journal.c:125:5: warning: no previous prototype for ‘jbd2_verify_csum_type’ [-Wmissing-prototypes]
fs/jbd2/journal.c:146:5: warning: no previous prototype for ‘jbd2_superblock_csum_verify’ [-Wmissing-prototypes]
fs/jbd2/journal.c:154:6: warning: no previous prototype for ‘jbd2_superblock_csum_set’ [-Wmissing-prototypes]
Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
If start_this_handle() fails then it leads to a use after free of
"handle".
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
Some of KERN_EMERG printk messages do not really deserve this log
level and the one in log_wait_commit() is even rather useless (the
journal has been previously aborted and *that* is where we should have
been complaining). So make some messages just KERN_ERR and remove the
useless message.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
If a handle runs out of space, we currently stop the kernel with a BUG
in jbd2_journal_dirty_metadata(). This makes it hard to figure out
what might be going on. So return an error of ENOSPC, so we can let
the file system layer figure out what is going on, to make it more
likely we can get useful debugging information). This should make it
easier to debug problems such as the one which was reported by:
https://bugzilla.kernel.org/show_bug.cgi?id=44731
The only two callers of this function are ext4_handle_dirty_metadata()
and ocfs2_journal_dirty(). The ocfs2 function will trigger a
BUG_ON(), which means there will be no change in behavior. The ext4
function will call ext4_error_inode() which will print the useful
debugging information and then handle the situation using ext4's error
handling mechanisms (i.e., which might mean halting the kernel or
remounting the file system read-only).
Also, since both file systems already call WARN_ON(), drop the WARN_ON
from jbd2_journal_dirty_metadata() to avoid two stack traces from
being displayed.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: ocfs2-devel@oss.oracle.com
Acked-by: Joel Becker <jlbec@evilplan.org>
In the jbd2 checksumming code, explicitly declare separate variables with
endianness information so that we don't get confused and screw things up again.
Also fixes sparse warnings.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
If jbd2_journal_restart() fails the handle will have been disconnected
from the current transaction. In this situation, the handle must not
be used for for any jbd2 function other than jbd2_journal_stop().
Enforce this with by treating a handle which has a NULL transaction
pointer as an aborted handle, and issue a kernel warning if
jbd2_journal_extent(), jbd2_journal_get_write_access(),
jbd2_journal_dirty_metadata(), etc. is called with an invalid handle.
This commit also fixes a bug where jbd2_journal_stop() would trip over
a kernel jbd2 assertion check when trying to free an invalid handle.
Also move the responsibility of setting current->journal_info to
start_this_handle(), simplifying the three users of this function.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reported-by: Younger Liu <younger.liu@huawei.com>
Cc: Jan Kara <jack@suse.cz>
Once we decrement transaction->t_updates, if this is the last handle
holding the transaction from closing, and once we release the
t_handle_lock spinlock, it's possible for the transaction to commit
and be released. In practice with normal kernels, this probably won't
happen, since the commit happens in a separate kernel thread and it's
unlikely this could all happen within the space of a few CPU cycles.
On the other hand, with a real-time kernel, this could potentially
happen, so save the tid found in transaction->t_tid before we release
t_handle_lock. It would require an insane configuration, such as one
where the jbd2 thread was set to a very high real-time priority,
perhaps because a high priority real-time thread is trying to read or
write to a file system. But some people who use real-time kernels
have been known to do insane things, including controlling
laser-wielding industrial robots. :-)
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
Some of the functions which modify the jbd2 superblock were not
updating the checksum before calling jbd2_write_superblock(). Move
the call to jbd2_superblock_csum_set() to jbd2_write_superblock(), so
that the checksum is calculated consistently.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: stable@vger.kernel.org
Commit b6e96d0067 ("jbd2: use module parameters instead of debugfs
for jbd_debug") removed any need for a dependency on DEBUG_FS. It
also moved the /sys variables out from underneath the typical debugfs
mount point. Delete the dependency and update the /sys path to where
the debug settings are currently.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Since the jbd_debug() is implemented with two separate printk()
calls, it can lead to corrupted and misleading debug output like
the following (see lines marked with "*"):
[ 290.339362] (fs/jbd2/journal.c, 203): kjournald2: kjournald2 wakes
[ 290.339365] (fs/jbd2/journal.c, 155): kjournald2: commit_sequence=42103, commit_request=42104
[ 290.339369] (fs/jbd2/journal.c, 158): kjournald2: OK, requests differ
[* 290.339376] (fs/jbd2/journal.c, 648): jbd2_log_wait_commit:
[* 290.339379] (fs/jbd2/commit.c, 370): jbd2_journal_commit_transaction: JBD2: want 42104, j_commit_sequence=42103
[* 290.339382] JBD2: starting commit of transaction 42104
[ 290.339410] (fs/jbd2/revoke.c, 566): jbd2_journal_write_revoke_records: Wrote 0 revoke records
[ 290.376555] (fs/jbd2/commit.c, 1088): jbd2_journal_commit_transaction: JBD2: commit 42104 complete, head 42079
i.e. the debug output from log_wait_commit and journal_commit_transaction
have become interleaved. The output should have been:
(fs/jbd2/journal.c, 648): jbd2_log_wait_commit: JBD2: want 42104, j_commit_sequence=42103
(fs/jbd2/commit.c, 370): jbd2_journal_commit_transaction: JBD2: starting commit of transaction 42104
It is expected that this is not easy to replicate -- I was only able
to cause it on preempt-rt kernels, and even then only under heavy
I/O load.
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Suggested-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Currently we see this output:
$git grep phase fs/jbd2
fs/jbd2/commit.c: jbd_debug(3, "JBD2: commit phase 1\n");
fs/jbd2/commit.c: jbd_debug(3, "JBD2: commit phase 2\n");
fs/jbd2/commit.c: jbd_debug(3, "JBD2: commit phase 2\n");
fs/jbd2/commit.c: jbd_debug(3, "JBD2: commit phase 3\n");
fs/jbd2/commit.c: jbd_debug(3, "JBD2: commit phase 4\n");
[...]
There is clearly a duplicate label for phase 2, and they are
both active (i.e. not in #if ... #else block). Rename them to
be "2a" and "2b" so the debug output is unambiguous.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
While trying to debug an an issue under extreme I/O loading
on preempt-rt kernels, the following backtrace was observed
via SysRQ output:
rm D ffff8802203afbc0 4600 4878 4748 0x00000000
ffff8802217bfb78 0000000000000082 ffff88021fc2bb80 ffff88021fc2bb80
ffff88021fc2bb80 ffff8802217bffd8 ffff8802217bffd8 ffff8802217bffd8
ffff88021f1d4c80 ffff88021fc2bb80 ffff8802217bfb88 ffff88022437b000
Call Trace:
[<ffffffff8172dc34>] schedule+0x24/0x70
[<ffffffff81225b5d>] jbd2_log_wait_commit+0xbd/0x140
[<ffffffff81060390>] ? __init_waitqueue_head+0x50/0x50
[<ffffffff81223635>] jbd2_log_do_checkpoint+0xf5/0x520
[<ffffffff81223b09>] __jbd2_log_wait_for_space+0xa9/0x1f0
[<ffffffff8121dc40>] start_this_handle.isra.10+0x2e0/0x530
[<ffffffff81060390>] ? __init_waitqueue_head+0x50/0x50
[<ffffffff8121e0a3>] jbd2__journal_start+0xc3/0x110
[<ffffffff811de7ce>] ? ext4_rmdir+0x6e/0x230
[<ffffffff8121e0fe>] jbd2_journal_start+0xe/0x10
[<ffffffff811f308b>] ext4_journal_start_sb+0x5b/0x160
[<ffffffff811de7ce>] ext4_rmdir+0x6e/0x230
[<ffffffff811435c5>] vfs_rmdir+0xd5/0x140
[<ffffffff8114370f>] do_rmdir+0xdf/0x120
[<ffffffff8105c6b4>] ? task_work_run+0x44/0x80
[<ffffffff81002889>] ? do_notify_resume+0x89/0x100
[<ffffffff817361ae>] ? int_signal+0x12/0x17
[<ffffffff81145d85>] sys_unlinkat+0x25/0x40
[<ffffffff81735f22>] system_call_fastpath+0x16/0x1b
What is interesting here, is that we call log_wait_commit, from
within wait_for_space, but we are still holding the checkpoint_mutex
as it surrounds mostly the whole of wait_for_space. And then, as we
are waiting, journal_commit_transaction can run, and if the JBD2_FLUSHED
bit is set, then we will also try to take the same checkpoint_mutex.
It seems that we need to drop the checkpoint_mutex while sitting in
jbd2_log_wait_commit, if we want to guarantee that progress can be made
by jbd2_journal_commit_transaction(). There does not seem to be
anything preempt-rt specific about this, other then perhaps increasing
the odds of it happening.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The state lock is taken after we are doing an assert on the state
value, not before. So we might in fact be doing an assert on a
transient value. Ensure the state check is within the scope of
the state lock being taken.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Current implementation of jbd2_journal_force_commit() is suboptimal because
result in empty and useless commits. But callers just want to force and wait
any unfinished commits. We already have jbd2_journal_force_commit_nested()
which does exactly what we want, except we are guaranteed that we do not hold
journal transaction open.
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
In some cases we cannot start a transaction because of locking
constraints and passing started transaction into those places is not
handy either because we could block transaction commit for too long.
Transaction reservation is designed to solve these issues. It
reserves a handle with given number of credits in the journal and the
handle can be later attached to the running transaction without
blocking on commit or checkpointing. Reserved handles do not block
transaction commit in any way, they only reduce maximum size of the
running transaction (because we have to always be prepared to
accomodate request for attaching reserved handle).
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
j_wait_logspace and j_wait_checkpoint are unused. Remove them.
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
jbd2_journal_extend() first checked whether transaction can accept
extending handle with more credits and then added credits to
t_outstanding_credits. This can race with start_this_handle() adding
another handle to a transaction and thus overbooking a transaction.
Make jbd2_journal_extend() use atomic_add_return() to close the race.
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
__jbd2_log_space_left() and jbd_space_needed() were kind of odd.
jbd_space_needed() accounted also credits needed for currently
committing transaction while it didn't account for credits needed for
control blocks. __jbd2_log_space_left() then accounted for control
blocks as a fraction of free space. Since results of these two
functions are always only compared against each other, this works
correct but is somewhat strange. Move the estimates so that
jbd_space_needed() returns number of blocks needed for a transaction
including control blocks and __jbd2_log_space_left() returns free
space in the journal (with the committing transaction already
subtracted). Rename functions to jbd2_log_space_left() and
jbd2_space_needed() while we are changing them.
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The comment about credit estimates isn't true anymore. We do what the
comment describes now.
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Currently when we add a buffer to a transaction, we wait until the
buffer is removed from BJ_Shadow list (so that we prevent any changes
to the buffer that is just written to the journal). This can take
unnecessarily long as a lot happens between the time the buffer is
submitted to the journal and the time when we remove the buffer from
BJ_Shadow list. (e.g. We wait for all data buffers in the
transaction, we issue a cache flush, etc.) Also this creates a
dependency of do_get_write_access() on transaction commit (namely
waiting for data IO to complete) which we want to avoid when
implementing transaction reservation.
So we modify commit code to set new BH_Shadow flag when temporary
shadowing buffer is created and we clear that flag once IO on that
buffer is complete. This allows do_get_write_access() to wait only
for BH_Shadow bit and thus removes the dependency on data IO
completion.
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Similarly as for metadata buffers, also log descriptor buffers don't
really need the journal head. So strip it and remove BJ_LogCtl list.
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When writing metadata to the journal, we create temporary buffer heads
for that task. We also attach journal heads to these buffer heads but
the only purpose of the journal heads is to keep buffers linked in
transaction's BJ_IO list. We remove the need for journal heads by
reusing buffer_head's b_assoc_buffers list for that purpose. Also
since BJ_IO list is just a temporary list for transaction commit, we
use a private list in jbd2_journal_commit_transaction() for that thus
removing BJ_IO list from transaction completely.
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Al Viro complained of a ton of bogosity with regards to the jbd2 block
tag header checksum. This one checksum is 16 bits, so cut off the
upper 16 bits and treat it as a 16-bit value and don't mess around
with be32* conversions. Fortunately metadata checksumming is still
"experimental" and not in a shipping e2fsprogs, so there should be few
users affected by this.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit tries to use kmem_cache_zalloc instead of kmem_cache_alloc/
memset when a new journal head is alloctated.
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
invalidatepage now accepts range to invalidate and there are two file
system using jbd2 also implementing punch hole feature which can benefit
from this. We need to implement the same thing for jbd2 layer in order to
allow those file system take benefit of this functionality.
This commit adds length argument to the jbd2_journal_invalidatepage()
and updates all instances in ext4 and ocfs2.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Pull VFS updates from Al Viro,
Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).
7kloc removed.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
don't bother with deferred freeing of fdtables
proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
proc: Make the PROC_I() and PDE() macros internal to procfs
proc: Supply a function to remove a proc entry by PDE
take cgroup_open() and cpuset_open() to fs/proc/base.c
ppc: Clean up scanlog
ppc: Clean up rtas_flash driver somewhat
hostap: proc: Use remove_proc_subtree()
drm: proc: Use remove_proc_subtree()
drm: proc: Use minor->index to label things, not PDE->name
drm: Constify drm_proc_list[]
zoran: Don't print proc_dir_entry data in debug
reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
proc: Supply an accessor for getting the data from a PDE's parent
airo: Use remove_proc_subtree()
rtl8192u: Don't need to save device proc dir PDE
rtl8187se: Use a dir under /proc/net/r8180/
proc: Add proc_mkdir_data()
proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
proc: Move PDE_NET() to fs/proc/proc_net.c
...
feature this merge window is a new ioctl EXT4_IOC_SWAP_BOOT which
allows installation of a hidden inode designed for boot loaders.
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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:
"Mostly performance and bug fixes, plus some cleanups. The one new
feature this merge window is a new ioctl EXT4_IOC_SWAP_BOOT which
allows installation of a hidden inode designed for boot loaders."
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (50 commits)
ext4: fix type-widening bug in inode table readahead code
ext4: add check for inodes_count overflow in new resize ioctl
ext4: fix Kconfig documentation for CONFIG_EXT4_DEBUG
ext4: fix online resizing for ext3-compat file systems
jbd2: trace when lock_buffer in do_get_write_access takes a long time
ext4: mark metadata blocks using bh flags
buffer: add BH_Prio and BH_Meta flags
ext4: mark all metadata I/O with REQ_META
ext4: fix readdir error in case inline_data+^dir_index.
ext4: fix readdir error in the case of inline_data+dir_index
jbd2: use kmem_cache_zalloc instead of kmem_cache_alloc/memset
ext4: mext_insert_extents should update extent block checksum
ext4: move quota initialization out of inode allocation transaction
ext4: reserve xattr index for Rich ACL support
jbd2: reduce journal_head size
ext4: clear buffer_uninit flag when submitting IO
ext4: use io_end for multiple bios
ext4: make ext4_bio_write_page() use BH_Async_Write flags
ext4: Use kstrtoul() instead of parse_strtoul()
ext4: defragmentation code cleanup
...
bh allocation uses kmem_cache_zalloc() so we needn't call
'init_buffer(bh, NULL, NULL)' and perform other set-zero-operations.
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While investigating interactivity problems it was clear that processes
sometimes stall for long periods of times if an attempt is made to
lock a buffer which is undergoing writeback. It would stall in
a trace looking something like
[<ffffffff811a39de>] __lock_buffer+0x2e/0x30
[<ffffffff8123a60f>] do_get_write_access+0x43f/0x4b0
[<ffffffff8123a7cb>] jbd2_journal_get_write_access+0x2b/0x50
[<ffffffff81220f79>] __ext4_journal_get_write_access+0x39/0x80
[<ffffffff811f3198>] ext4_reserve_inode_write+0x78/0xa0
[<ffffffff811f3209>] ext4_mark_inode_dirty+0x49/0x220
[<ffffffff811f57d1>] ext4_dirty_inode+0x41/0x60
[<ffffffff8119ac3e>] __mark_inode_dirty+0x4e/0x2d0
[<ffffffff8118b9b9>] update_time+0x79/0xc0
[<ffffffff8118ba98>] file_update_time+0x98/0x100
[<ffffffff81110ffc>] __generic_file_aio_write+0x17c/0x3b0
[<ffffffff811112aa>] generic_file_aio_write+0x7a/0xf0
[<ffffffff811ea853>] ext4_file_write+0x83/0xd0
[<ffffffff81172b23>] do_sync_write+0xa3/0xe0
[<ffffffff811731ae>] vfs_write+0xae/0x180
[<ffffffff8117361d>] sys_write+0x4d/0x90
[<ffffffff8159d62d>] system_call_fastpath+0x1a/0x1f
[<ffffffffffffffff>] 0xffffffffffffffff
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The jbd2_alloc_handle() function is only called by new_handle(). So
this commit uses kmem_cache_zalloc() instead of
kmem_cache_alloc()/memset().
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The only part of proc_dir_entry the code outside of fs/proc
really cares about is PDE(inode)->data. Provide a helper
for that; static inline for now, eventually will be moved
to fs/proc, along with the knowledge of struct proc_dir_entry
layout.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The following race is possible:
[kjournald2] other_task
jbd2_journal_commit_transaction()
j_state = T_FINISHED;
spin_unlock(&journal->j_list_lock);
->jbd2_journal_remove_checkpoint()
->jbd2_journal_free_transaction();
->kmem_cache_free(transaction)
->j_commit_callback(journal, transaction);
-> USE_AFTER_FREE
WARNING: at lib/list_debug.c:62 __list_del_entry+0x1c0/0x250()
Hardware name:
list_del corruption. prev->next should be ffff88019a4ec198, but was 6b6b6b6b6b6b6b6b
Modules linked in: cpufreq_ondemand acpi_cpufreq freq_table mperf coretemp kvm_intel kvm crc32c_intel ghash_clmulni_intel microcode sg xhci_hcd button sd_mod crc_t10dif aesni_intel ablk_helper cryptd lrw aes_x86_64 xts gf128mul ahci libahci pata_acpi ata_generic dm_mirror dm_region_hash dm_log dm_mod
Pid: 16400, comm: jbd2/dm-1-8 Tainted: G W 3.8.0-rc3+ #107
Call Trace:
[<ffffffff8106fb0d>] warn_slowpath_common+0xad/0xf0
[<ffffffff8106fc06>] warn_slowpath_fmt+0x46/0x50
[<ffffffff813637e9>] ? ext4_journal_commit_callback+0x99/0xc0
[<ffffffff8148cae0>] __list_del_entry+0x1c0/0x250
[<ffffffff813637bf>] ext4_journal_commit_callback+0x6f/0xc0
[<ffffffff813ca336>] jbd2_journal_commit_transaction+0x23a6/0x2570
[<ffffffff8108aa42>] ? try_to_del_timer_sync+0x82/0xa0
[<ffffffff8108b491>] ? del_timer_sync+0x91/0x1e0
[<ffffffff813d3ecf>] kjournald2+0x19f/0x6a0
[<ffffffff810ad630>] ? wake_up_bit+0x40/0x40
[<ffffffff813d3d30>] ? bit_spin_lock+0x80/0x80
[<ffffffff810ac6be>] kthread+0x10e/0x120
[<ffffffff810ac5b0>] ? __init_kthread_worker+0x70/0x70
[<ffffffff818ff6ac>] ret_from_fork+0x7c/0xb0
[<ffffffff810ac5b0>] ? __init_kthread_worker+0x70/0x70
In order to demonstrace this issue one should mount ext4 with mount -o
discard option on SSD disk. This makes callback longer and race
window becomes wider.
In order to fix this we should mark transaction as finished only after
callbacks have completed
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
In the case where an inode has a very stale transaction id (tid) in
i_datasync_tid or i_sync_tid, it's possible that after a very large
(2**31) number of transactions, that the tid number space might wrap,
causing tid_geq()'s calculations to fail.
Commit deeeaf13 "jbd2: fix fsync() tid wraparound bug", later modified
by commit e7b04ac0 "jbd2: don't wake kjournald unnecessarily",
attempted to fix this problem, but it only avoided kjournald spinning
forever by fixing the logic in jbd2_log_start_commit().
Unfortunately, in the codepaths in fs/ext4/fsync.c and fs/ext4/inode.c
that might call jbd2_log_start_commit() with a stale tid, those
functions will subsequently call jbd2_log_wait_commit() with the same
stale tid, and then wait for a very long time. To fix this, we
replace the calls to jbd2_log_start_commit() and
jbd2_log_wait_commit() with a call to a new function,
jbd2_complete_transaction(), which will correctly handle stale tid's.
As a bonus, jbd2_complete_transaction() will avoid locking
j_state_lock for writing unless a commit needs to be started. This
should have a small (but probably not measurable) improvement for
ext4's scalability.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Reported-by: George Barnett <gbarnett@atlassian.com>
Cc: stable@vger.kernel.org
jbd2_journal_dirty_metadata() didn't get a reference to journal_head it
was working with. This is OK in most of the cases since the journal head
should be attached to a transaction but in rare occasions when we are
journalling data, __ext4_journalled_writepage() can race with
jbd2_journal_invalidatepage() stripping buffers from a page and thus
journal head can be freed under hands of jbd2_journal_dirty_metadata().
Fix the problem by getting own journal head reference in
jbd2_journal_dirty_metadata() (and also in jbd2_journal_set_triggers()
which can possibly have the same issue).
Reported-by: Zheng Liu <gnehzuil.liu@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
There are multiple reasons to move away from debugfs. First of all,
we are only using it for a single parameter, and it is much more
complicated to set up (some 30 lines of code compared to 3), and one
more thing that might fail while loading the jbd2 module.
Secondly, as a module paramter it can be specified as a boot option if
jbd2 is built into the kernel, or as a parameter when the module is
loaded, and it can also be manipulated dynamically under
/sys/module/jbd2/parameters/jbd2_debug. So it is more flexible.
Ultimately we want to move away from using jbd_debug() towards
tracepoints, but for now this is still a useful simplification of the
code base.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Handles which stay open a long time are problematic when it comes time
to close down a transaction so it can be committed. These tracepoints
will help us determine which ones are the problematic ones, and to
validate whether changes makes things better or worse.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
OGAWA Hirofumi
Jan Kara
Dmitry Monakhov
Linus Torvalds
Junxiao Bi
Mel Gorman
Daeho Jeong
Jan Kara
Darrick J. Wong
Lukas Czerner
Rasmus Villemoes
Michal Hocko
Joseph Qi
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