The iput() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Jan Kara <jack@suse.cz>
While the hash function used by the revoke hashtable is good somewhere else,
it's not really good here.
The default hash shift (8) means that one third of the hashing function
gets lost (and is undefined anyways (8 - 12 = negative shift)):
"(block << (hash_shift - 12))) & (table->hash_size - 1)"
Instead, just use the kernel's generic hash function that gets used everywhere
else.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
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>
journal_init_revoke_table is only called with positive hash_size
(JOURNAL_REVOKE_DEFAULT_HASH) so we can replace loop shift by ilog2
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Jan Kara <jack@suse.cz>
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>
This reverts commit 05713082ab. The idea
to remove __GFP_NOFAIL was opposed by Andrew Morton. Although mm guys do
want to get rid of __GFP_NOFAIL users, opencoding the allocation retry
is even worse.
See emails following
http://www.gossamer-threads.com/lists/linux/kernel/1809153#1809153
Signed-off-by: Jan Kara <jack@suse.cz>
Backport of jbd2 commit 169f1a2a87
("jbd2: use a single printk for jbd_debug()")
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.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jan Kara <jack@suse.cz>
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.
Backport of jbd2 commit 3ca841c106
("jbd2: relocate assert after state lock in journal_commit_transaction()")
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jan Kara <jack@suse.cz>
->invalidatepage() aop now accepts range to invalidate so we can make
use of it in journal_invalidatepage() and all the users in ext3 file
system. Also update ext3 trace point to print out length argument.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Pull ext3/jbd fixes from Jan Kara:
"A couple of ext3/jbd fixes"
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
jbd: use kmem_cache_zalloc for allocating journal head
jbd: use kmem_cache_zalloc instead of kmem_cache_alloc/memset
jbd: don't wait (forever) for stale tid caused by wraparound
ext3: fix data=journal fast mount/umount hang
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>
Walking a bio's page mappings has proved problematic, so create a new
bio flag to indicate that a bio's data needs to be snapshotted in order
to guarantee stable pages during writeback. Next, for the one user
(ext3/jbd) of snapshotting, hook all the places where writes can be
initiated without PG_writeback set, and set BIO_SNAP_STABLE there.
We must also flag journal "metadata" bios for stable writeout, since
file data can be written through the journal. Finally, the
MS_SNAP_STABLE mount flag (only used by ext3) is now superfluous, so get
rid of it.
[akpm@linux-foundation.org: rename _submit_bh()'s `flags' to `bio_flags', delobotomize the _submit_bh declaration]
[akpm@linux-foundation.org: teeny cleanup]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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: Jan Kara <jack@suse.cz>
Signed-off-by: Jan Kara <jack@suse.cz>
Now jbd_alloc_handle 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: Jan Kara <jack@suse.cz>
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 d9b0193 "jbd: fix fsync() tid wraparound bug" attempted to fix
this problem, but it only avoided kjournald spinning forever by fixing
the logic in jbd_log_start_commit().
Signed-off-by: Jan Kara <jack@suse.cz>
Don't send an extra wakeup to kjournald in the case where we
already have the proper target in j_commit_request, i.e. that
commit has already been requested for commit.
commit d9b0193 "jbd: fix fsync() tid wraparound bug" changed
the logic leading to a wakeup, but it caused some extra wakeups
which were found to lead to a measurable performance regression.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Pull trivial branch from Jiri Kosina:
"Usual stuff -- comment/printk typo fixes, documentation updates, dead
code elimination."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
HOWTO: fix double words typo
x86 mtrr: fix comment typo in mtrr_bp_init
propagate name change to comments in kernel source
doc: Update the name of profiling based on sysfs
treewide: Fix typos in various drivers
treewide: Fix typos in various Kconfig
wireless: mwifiex: Fix typo in wireless/mwifiex driver
messages: i2o: Fix typo in messages/i2o
scripts/kernel-doc: check that non-void fcts describe their return value
Kernel-doc: Convention: Use a "Return" section to describe return values
radeon: Fix typo and copy/paste error in comments
doc: Remove unnecessary declarations from Documentation/accounting/getdelays.c
various: Fix spelling of "asynchronous" in comments.
Fix misspellings of "whether" in comments.
eisa: Fix spelling of "asynchronous".
various: Fix spelling of "registered" in comments.
doc: fix quite a few typos within Documentation
target: iscsi: fix comment typos in target/iscsi drivers
treewide: fix typo of "suport" in various comments and Kconfig
treewide: fix typo of "suppport" in various comments
...
Commit 09e05d48 introduced a wait for transaction commit into
journal_unmap_buffer() in the case we are truncating a buffer undergoing commit
in the page stradding i_size on a filesystem with blocksize < pagesize. Sadly
we forgot to drop buffer lock before waiting for transaction commit and thus
deadlock is possible when kjournald wants to lock the buffer.
Fix the problem by dropping the buffer lock before waiting for transaction
commit. Since we are still holding page lock (and that is OK), buffer cannot
disappear under us.
CC: stable@vger.kernel.org # Wherever commit 09e05d48 was taken
Signed-off-by: Jan Kara <jack@suse.cz>
"Whether" is misspelled in various comments across the tree; this
fixes them. No code changes.
Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
ext3 users of data=journal mode with blocksize < pagesize were occasionally
hitting assertion failure in journal_commit_transaction() checking whether the
transaction has at least as many credits reserved as buffers attached. The
core of the problem is that when a file gets truncated, buffers that still need
checkpointing or that are attached to the committing transaction are left with
buffer_mapped set. When this happens to buffers beyond i_size attached to a
page stradding i_size, subsequent write extending the file will see these
buffers and as they are mapped (but underlying blocks were freed) things go
awry from here.
The assertion failure just coincidentally (and in this case luckily as we would
start corrupting filesystem) triggers due to journal_head not being properly
cleaned up as well.
Under some rare circumstances this bug could even hit data=ordered mode users.
There the assertion won't trigger and we would end up corrupting the
filesystem.
We fix the problem by unmapping buffers if possible (in lots of cases we just
need a buffer attached to a transaction as a place holder but it must not be
written out anyway). And in one case, we just have to bite the bullet and wait
for transaction commit to finish.
Reviewed-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Jan Kara <jack@suse.cz>
This sequence:
results in an IO error when unmounting the RO filesystem. The bug was
introduced by:
commit 9754e39c7b
Author: Jan Kara <jack@suse.cz>
Date: Sat Apr 7 12:33:03 2012 +0200
jbd: Split updating of journal superblock and marking journal empty
which lost some of the magic in journal_update_superblock() which
used to test for a journal with no outstanding transactions.
This is a port of a jbd2 fix by Eric Sandeen.
CC: <stable@vger.kernel.org> # 3.4.x
Signed-off-by: Jan Kara <jack@suse.cz>
The '->write_super' superblock method is gone, and this patch removes all the
references to 'write_super' from various jbd and jbd2.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If journal superblock is written only in disk's caches and other transaction
starts reusing space of the transaction cleaned from the log, it can happen
blocks of a new transaction reach the disk before journal superblock. When
power failure happens in such case, subsequent journal replay would still try
to replay the old transaction but some of it's blocks may be already
overwritten by the new transaction. For this reason we must use WRITE_FUA when
updating log tail and we must first write new log tail to disk and update
in-memory information only after that.
Signed-off-by: Jan Kara <jack@suse.cz>
There are some log tail updates that are not protected by j_checkpoint_mutex.
Some of these are harmless because they happen during startup or shutdown but
updates in journal_commit_transaction() and journal_flush() can really race
with other log tail updates (e.g. someone doing journal_flush() with someone
running cleanup_journal_tail()). So protect all log tail updates with
j_checkpoint_mutex.
Signed-off-by: Jan Kara <jack@suse.cz>
There are three case of updating journal superblock. In the first case, we want
to mark journal as empty (setting s_sequence to 0), in the second case we want
to update log tail, in the third case we want to update s_errno. Split these
cases into separate functions. It makes the code slightly more straightforward
and later patches will make the distinction even more important.
Signed-off-by: Jan Kara <jack@suse.cz>
Currently we write out all journal buffers in WRITE_SYNC mode. This improves
performance for fsync heavy workloads but hinders performance when writes
are mostly asynchronous, most noticably it slows down readers and users
complain about slow desktop response etc.
So submit writes as asynchronous in the normal case and only submit writes as
WRITE_SYNC if we detect someone is waiting for current transaction commit.
I've gathered some numbers to back this change. The first is the read latency
test. It measures time to read 1 MB after several seconds of sleeping in
presence of streaming writes.
Top 10 times (out of 90) in us:
Before After
2131586 697473
1709932 557487
1564598 535642
1480462 347573
1478579 323153
1408496 222181
1388960 181273
1329565 181070
1252486 172832
1223265 172278
Average:
619377 82180
So the improvement in both maximum and average latency is massive.
I've measured fsync throughput by:
fs_mark -n 100 -t 1 -s 16384 -d /mnt/fsync/ -S 1 -L 4
in presence of streaming reader. The numbers (fsyncs/s) are:
Before After
9.9 6.3
6.8 6.0
6.3 6.2
5.8 6.1
So fsync performance seems unharmed by this change.
Signed-off-by: Jan Kara <jack@suse.cz>
Assorted extensions and fixes including:
* Introduction of early/late suspend/hibernation device callbacks.
* Generic PM domains extensions and fixes.
* devfreq updates from Axel Lin and MyungJoo Ham.
* Device PM QoS updates.
* Fixes of concurrency problems with wakeup sources.
* System suspend and hibernation fixes.
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Merge tag 'pm-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates for 3.4 from Rafael Wysocki:
"Assorted extensions and fixes including:
* Introduction of early/late suspend/hibernation device callbacks.
* Generic PM domains extensions and fixes.
* devfreq updates from Axel Lin and MyungJoo Ham.
* Device PM QoS updates.
* Fixes of concurrency problems with wakeup sources.
* System suspend and hibernation fixes."
* tag 'pm-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (43 commits)
PM / Domains: Check domain status during hibernation restore of devices
PM / devfreq: add relation of recommended frequency.
PM / shmobile: Make MTU2 driver use pm_genpd_dev_always_on()
PM / shmobile: Make CMT driver use pm_genpd_dev_always_on()
PM / shmobile: Make TMU driver use pm_genpd_dev_always_on()
PM / Domains: Introduce "always on" device flag
PM / Domains: Fix hibernation restore of devices, v2
PM / Domains: Fix handling of wakeup devices during system resume
sh_mmcif / PM: Use PM QoS latency constraint
tmio_mmc / PM: Use PM QoS latency constraint
PM / QoS: Make it possible to expose PM QoS latency constraints
PM / Sleep: JBD and JBD2 missing set_freezable()
PM / Domains: Fix include for PM_GENERIC_DOMAINS=n case
PM / Freezer: Remove references to TIF_FREEZE in comments
PM / Sleep: Add more wakeup source initialization routines
PM / Hibernate: Enable usermodehelpers in hibernate() error path
PM / Sleep: Make __pm_stay_awake() delete wakeup source timers
PM / Sleep: Fix race conditions related to wakeup source timer function
PM / Sleep: Fix possible infinite loop during wakeup source destruction
PM / Hibernate: print physical addresses consistently with other parts of kernel
...
With the latest and greatest changes to the freezer, I started seeing
panics that were caused by jbd2 running post-process freezing and
hitting the canary BUG_ON for non-TuxOnIce I/O submission. I've traced
this back to a lack of set_freezable calls in both jbd and jbd2. Since
they're clearly meant to be frozen (there are tests for freezing()), I
submit the following patch to add the missing calls.
Signed-off-by: Nigel Cunningham <nigel@tuxonice.net>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
When we reach cleanup_journal_tail(), there is no guarantee that
checkpointed buffers are on a stable storage - especially if buffers were
written out by log_do_checkpoint(), they are likely to be only in disk's
caches. Thus when we update journal superblock, effectively removing old
transaction from journal, this write of superblock can get to stable storage
before those checkpointed buffers which can result in filesystem corruption
after a crash.
A similar problem can happen if we replay the journal and wipe it before
flushing disk's caches.
Thus we must unconditionally issue a cache flush before we update journal
superblock in these cases. The fix is slightly complicated by the fact that we
have to get log tail before we issue cache flush but we can store it in the
journal superblock only after the cache flush. Otherwise we risk races where
new tail is written before appropriate cache flush is finished.
I managed to reproduce the corruption using somewhat tweaked Chris Mason's
barrier-test scheduler. Also this should fix occasional reports of 'Bit already
freed' filesystem errors which are totally unreproducible but inspection of
several fs images I've gathered over time points to a problem like this.
CC: stable@kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
ext2/3/4: delete unneeded includes of module.h
ext{3,4}: Fix potential race when setversion ioctl updates inode
udf: Mark LVID buffer as uptodate before marking it dirty
ext3: Don't warn from writepage when readonly inode is spotted after error
jbd: Remove j_barrier mutex
reiserfs: Force inode evictions before umount to avoid crash
reiserfs: Fix quota mount option parsing
udf: Treat symlink component of type 2 as /
udf: Fix deadlock when converting file from in-ICB one to normal one
udf: Cleanup calling convention of inode_getblk()
ext2: Fix error handling on inode bitmap corruption
ext3: Fix error handling on inode bitmap corruption
ext3: replace ll_rw_block with other functions
ext3: NULL dereference in ext3_evict_inode()
jbd: clear revoked flag on buffers before a new transaction started
ext3: call ext3_mark_recovery_complete() when recovery is really needed
j_barrier mutex is used for serializing different journal lock operations. The
problem with it is that e.g. FIFREEZE ioctl results in process leaving kernel
with j_barrier mutex held which makes lockdep freak out. Also hibernation code
wants to freeze filesystem but it cannot do so because it then cannot hibernate
the system because of mutex being locked.
So we remove j_barrier mutex and use direct wait on j_barrier_count instead.
Since locking journal is a rare operation we don't have to care about fairness
or such things.
CC: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Jan Kara <jack@suse.cz>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (53 commits)
Kconfig: acpi: Fix typo in comment.
misc latin1 to utf8 conversions
devres: Fix a typo in devm_kfree comment
btrfs: free-space-cache.c: remove extra semicolon.
fat: Spelling s/obsolate/obsolete/g
SCSI, pmcraid: Fix spelling error in a pmcraid_err() call
tools/power turbostat: update fields in manpage
mac80211: drop spelling fix
types.h: fix comment spelling for 'architectures'
typo fixes: aera -> area, exntension -> extension
devices.txt: Fix typo of 'VMware'.
sis900: Fix enum typo 'sis900_rx_bufer_status'
decompress_bunzip2: remove invalid vi modeline
treewide: Fix comment and string typo 'bufer'
hyper-v: Update MAINTAINERS
treewide: Fix typos in various parts of the kernel, and fix some comments.
clockevents: drop unknown Kconfig symbol GENERIC_CLOCKEVENTS_MIGR
gpio: Kconfig: drop unknown symbol 'CS5535_GPIO'
leds: Kconfig: Fix typo 'D2NET_V2'
sound: Kconfig: drop unknown symbol ARCH_CLPS7500
...
Fix up trivial conflicts in arch/powerpc/platforms/40x/Kconfig (some new
kconfig additions, close to removed commented-out old ones)
Currently, we clear revoked flag only when a block is reused. However,
this can tigger a false journal error. Consider a situation when a block
is used as a meta block and is deleted(revoked) in ordered mode, then the
block is allocated as a data block to a file. At this moment, user changes
the file's journal mode from ordered to journaled and truncates the file.
The block will be considered re-revoked by journal because it has revoked
flag still pending from the last transaction and an assertion triggers.
We fix the problem by keeping the revoked status more uptodate - we clear
revoked flag when switching revoke tables to reflect there is no revoked
buffers in current transaction any more.
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
There is no reason to export two functions for entering the
refrigerator. Calling refrigerator() instead of try_to_freeze()
doesn't save anything noticeable or removes any race condition.
* Rename refrigerator() to __refrigerator() and make it return bool
indicating whether it scheduled out for freezing.
* Update try_to_freeze() to return bool and relay the return value of
__refrigerator() if freezing().
* Convert all refrigerator() users to try_to_freeze().
* Update documentation accordingly.
* While at it, add might_sleep() to try_to_freeze().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Samuel Ortiz <samuel@sortiz.org>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: Christoph Hellwig <hch@infradead.org>
I hit a J_ASSERT(blocknr != 0) failure in cleanup_journal_tail() when
mounting a fsfuzzed ext3 image. It turns out that the corrupted ext3
image has s_first = 0 in journal superblock, and the 0 is passed to
journal->j_head in journal_reset(), then to blocknr in
cleanup_journal_tail(), in the end the J_ASSERT failed.
So validate s_first after reading journal superblock from disk in
journal_get_superblock() to ensure s_first is valid.
The following script could reproduce it:
fstype=ext3
blocksize=1024
img=$fstype.img
offset=0
found=0
magic="c0 3b 39 98"
dd if=/dev/zero of=$img bs=1M count=8
mkfs -t $fstype -b $blocksize -F $img
filesize=`stat -c %s $img`
while [ $offset -lt $filesize ]
do
if od -j $offset -N 4 -t x1 $img | grep -i "$magic";then
echo "Found journal: $offset"
found=1
break
fi
offset=`echo "$offset+$blocksize" | bc`
done
if [ $found -ne 1 ];then
echo "Magic \"$magic\" not found"
exit 1
fi
dd if=/dev/zero of=$img seek=$(($offset+23)) conv=notrunc bs=1 count=1
mkdir -p ./mnt
mount -o loop $img ./mnt
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
In journal checkpoint, we write the buffer and wait for its finish.
But in cfq, the async queue has a very low priority, and in our test,
if there are too many sync queues and every queue is filled up with
requests, and the process will hang waiting for the log space.
So this patch tries to use WRITE_SYNC in __flush_batch so that the request will
be moved into sync queue and handled by cfq timely. We also use the new plug,
sot that all the WRITE_SYNC requests can be given as a whole when we unplug it.
Reported-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
journal_remove_journal_head() can oops when trying to access journal_head
returned by bh2jh(). This is caused for example by the following race:
TASK1 TASK2
journal_commit_transaction()
...
processing t_forget list
__journal_refile_buffer(jh);
if (!jh->b_transaction) {
jbd_unlock_bh_state(bh);
journal_try_to_free_buffers()
journal_grab_journal_head(bh)
jbd_lock_bh_state(bh)
__journal_try_to_free_buffer()
journal_put_journal_head(jh)
journal_remove_journal_head(bh);
journal_put_journal_head() in TASK2 sees that b_jcount == 0 and buffer is not
part of any transaction and thus frees journal_head before TASK1 gets to doing
so. Note that even buffer_head can be released by try_to_free_buffers() after
journal_put_journal_head() which adds even larger opportunity for oops (but I
didn't see this happen in reality).
Fix the problem by making transactions hold their own journal_head reference
(in b_jcount). That way we don't have to remove journal_head explicitely via
journal_remove_journal_head() and instead just remove journal_head when
b_jcount drops to zero. The result of this is that [__]journal_refile_buffer(),
[__]journal_unfile_buffer(), and __journal_remove_checkpoint() can free
journal_head which needs modification of a few callers. Also we have to be
careful because once journal_head is removed, buffer_head might be freed as
well. So we have to get our own buffer_head reference where it matters.
Signed-off-by: Jan Kara <jack@suse.cz>
journal_get_create_access should drop jh->b_jcount in error handling path
Signed-off-by: Ding Dinghua <dingdinghua@nrchpc.ac.cn>
Signed-off-by: Jan Kara <jack@suse.cz>
The callers of start_this_handle() (or better ext3_journal_start()) are not
really prepared to handle allocation failures. Such failures can for example
result in silent data loss when it happens in ext3_..._writepage(). OTOH
__GFP_NOFAIL is going away so we just retry allocation in start_this_handle().
This loop is potentially dangerous because the oom killer cannot be invoked
for GFP_NOFS allocation, so there is a potential for infinitely looping.
But still this is better than silent data loss.
Signed-off-by: Jan Kara <jack@suse.cz>
This commit adds fixed tracepoint for jbd. It has been based on fixed
tracepoints for jbd2, however there are missing those for collecting
statistics, since I think that it will require more intrusive patch so I
should have its own commit, if someone decide that it is needed. Also
there are new tracepoints in __journal_drop_transaction() and
journal_update_superblock().
The list of jbd tracepoints:
jbd_checkpoint
jbd_start_commit
jbd_commit_locking
jbd_commit_flushing
jbd_commit_logging
jbd_drop_transaction
jbd_end_commit
jbd_do_submit_data
jbd_cleanup_journal_tail
jbd_update_superblock_end
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jan Kara <jack@suse.cz>
journal_start returns an ERR_PTR() value rather than NULL on failure.
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
summarise_journal_usage seems to be obsolete for a long time,
so remove it.
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
In do_get_write_access() we wait on BH_Unshadow bit for buffer to get
from shadow state. The waking code in journal_commit_transaction() has
a bug because it does not issue a memory barrier after the buffer is moved
from the shadow state and before wake_up_bit() is called. Thus a waitqueue
check can happen before the buffer is actually moved from the shadow state
and waiting process may never be woken. Fix the problem by issuing proper
barrier.
CC: stable@kernel.org
Reported-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
If an application program does not make any changes to the indirect
blocks or extent tree, i_datasync_tid will not get updated. If there
are enough commits (i.e., 2**31) such that tid_geq()'s calculations
wrap, and there isn't a currently active transaction at the time of
the fdatasync() call, this can end up triggering a BUG_ON in
fs/jbd/commit.c:
J_ASSERT(journal->j_running_transaction != NULL);
It's pretty rare that this can happen, since it requires the use of
fdatasync() plus *very* frequent and excessive use of fsync(). But
with the right workload, it can.
We fix this by replacing the use of tid_geq() with an equality test,
since there's only one valid transaction id that is valid for us to
start: namely, the currently running transaction (if it exists).
CC: stable@kernel.org
Reported-by: Martin_Zielinski@McAfee.com
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits)
Documentation/iostats.txt: bit-size reference etc.
cfq-iosched: removing unnecessary think time checking
cfq-iosched: Don't clear queue stats when preempt.
blk-throttle: Reset group slice when limits are changed
blk-cgroup: Only give unaccounted_time under debug
cfq-iosched: Don't set active queue in preempt
block: fix non-atomic access to genhd inflight structures
block: attempt to merge with existing requests on plug flush
block: NULL dereference on error path in __blkdev_get()
cfq-iosched: Don't update group weights when on service tree
fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away
block: Require subsystems to explicitly allocate bio_set integrity mempool
jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
fs: make fsync_buffers_list() plug
mm: make generic_writepages() use plugging
blk-cgroup: Add unaccounted time to timeslice_used.
block: fixup plugging stubs for !CONFIG_BLOCK
block: remove obsolete comments for blkdev_issue_zeroout.
blktrace: Use rq->cmd_flags directly in blk_add_trace_rq.
...
Fix up conflicts in fs/{aio.c,super.c}
'write_op' was still used, even though it was always WRITE_SYNC now.
Add plugging around the cases where it submits IO, and flush them
before we end up waiting for that IO.
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Markus Elfring