Commit Graph

523 Commits

Author SHA1 Message Date
Jan Kara 188c299e2a ext4: Support for checksumming from journal triggers
JBD2 layer support triggers which are called when journaling layer moves
buffer to a certain state. We can use the frozen trigger, which gets
called when buffer data is frozen and about to be written out to the
journal, to compute block checksums for some buffer types (similarly as
does ocfs2). This avoids unnecessary repeated recomputation of the
checksum (at the cost of larger window where memory corruption won't be
caught by checksumming) and is even necessary when there are
unsynchronized updaters of the checksummed data.

So add superblock and journal trigger type arguments to
ext4_journal_get_write_access() and ext4_journal_get_create_access() so
that frozen triggers can be set accordingly. Also add inode argument to
ext4_walk_page_buffers() and all the callbacks used with that function
for the same purpose. This patch is mostly only a change of prototype of
the above mentioned functions and a few small helpers. Real checksumming
will come later.

Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210816095713.16537-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-08-30 23:36:50 -04:00
Theodore Ts'o b33d9f5909 jbd2: add sparse annotations for add_transaction_credits()
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-08-30 23:36:50 -04:00
Theodore Ts'o 4009cc7ad6 jbd2: clean up two gcc -Wall warnings in recovery.c
Fix a signed vs unsigned and a void * pointer arithmetic warning.

This cleanup is also in e2fsprogs commit aec460db9a93 ("e2fsck: clean
up two gcc -Wall warnings in recovery.c").

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-08-10 14:12:27 -04:00
Theodore Ts'o 390add0cc9 jbd2: fix clang warning in recovery.c
Remove unused variable store which was never used.

This fix is also in e2fsprogs commit 99a2294f85f0 ("e2fsck: value
stored to err is never read").

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-08-10 12:55:51 -04:00
Theodore Ts'o a20d1cebb9 jbd2: fix portability problems caused by unaligned accesses
This commit applies the e2fsck/recovery.c portions of commit
1e0c8ca7c08a ("e2fsck: fix portability problems caused by unaligned
accesses) from the e2fsprogs git tree.

The on-disk format for the ext4 journal can have unaigned 32-bit
integers.  This can happen when replaying a journal using a obsolete
checksum format (which was never popularly used, since the v3 format
replaced v2 while the metadata checksum feature was being stablized).

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-08-10 10:11:20 -04:00
Theodore Ts'o 0705e8d1e2 ext4: inline jbd2_journal_[un]register_shrinker()
The function jbd2_journal_unregister_shrinker() was getting called
twice when the file system was getting unmounted.  On Power and ARM
platforms this was causing kernel crash when unmounting the file
system, when a percpu_counter was destroyed twice.

Fix this by removing jbd2_journal_[un]register_shrinker() functions,
and inlining the shrinker setup and teardown into
journal_init_common() and jbd2_journal_destroy().  This means that
ext4 and ocfs2 now no longer need to know about registering and
unregistering jbd2's shrinker.

Also, while we're at it, rename the percpu counter from
j_jh_shrink_count to j_checkpoint_jh_count, since this makes it
clearer what this counter is intended to track.

Link: https://lore.kernel.org/r/20210705145025.3363130-1-tytso@mit.edu
Fixes: 4ba3fcdde7 ("jbd2,ext4: add a shrinker to release checkpointed buffers")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-07-08 08:37:31 -04:00
Zhang Yi 16aa4c9a1f jbd2: export jbd2_journal_[un]register_shrinker()
Export jbd2_journal_[un]register_shrinker() to fix this error when
ext4 is built as a module:

  ERROR: modpost: "jbd2_journal_unregister_shrinker" undefined!
  ERROR: modpost: "jbd2_journal_register_shrinker" undefined!

Fixes: 4ba3fcdde7 ("jbd2,ext4: add a shrinker to release checkpointed buffers")
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210630083638.140218-1-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-06-30 11:05:00 -04:00
Zhang Yi dbf2bab793 jbd2: simplify journal_clean_one_cp_list()
Now that __try_to_free_cp_buf() remove checkpointed buffer or transaction
when the buffer is not 'busy', which is only called by
journal_clean_one_cp_list(). This patch simplify this function by remove
__try_to_free_cp_buf() and invoke __cp_buffer_busy() directly.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210610112440.3438139-7-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-06-24 10:55:39 -04:00
Zhang Yi 4ba3fcdde7 jbd2,ext4: add a shrinker to release checkpointed buffers
Current metadata buffer release logic in bdev_try_to_free_page() have
a lot of use-after-free issues when umount filesystem concurrently, and
it is difficult to fix directly because ext4 is the only user of
s_op->bdev_try_to_free_page callback and we may have to add more special
refcount or lock that is only used by ext4 into the common vfs layer,
which is unacceptable.

One better solution is remove the bdev_try_to_free_page callback, but
the real problem is we cannot easily release journal_head on the
checkpointed buffer, so try_to_free_buffers() cannot release buffers and
page under memory pressure, which is more likely to trigger
out-of-memory. So we cannot remove the callback directly before we find
another way to release journal_head.

This patch introduce a shrinker to free journal_head on the checkpointed
transaction. After the journal_head got freed, try_to_free_buffers()
could free buffer properly.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210610112440.3438139-6-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-06-24 10:54:49 -04:00
Zhang Yi 214eb5a4d8 jbd2: remove redundant buffer io error checks
Now that __jbd2_journal_remove_checkpoint() can detect buffer io error
and mark journal checkpoint error, then we abort the journal later
before updating log tail to ensure the filesystem works consistently.
So we could remove other redundant buffer io error checkes.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210610112440.3438139-5-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-06-24 10:33:50 -04:00
Zhang Yi 235d68069c jbd2: don't abort the journal when freeing buffers
Now that we can be sure the journal is aborted once a buffer has failed
to be written back to disk, we can remove the journal abort logic in
jbd2_journal_try_to_free_buffers() which was introduced in
commit c044f3d836 ("jbd2: abort journal if free a async write error
metadata buffer"), because it may cost and propably is not safe.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210610112440.3438139-4-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-06-24 10:33:50 -04:00
Zhang Yi fcf37549ae jbd2: ensure abort the journal if detect IO error when writing original buffer back
Although we merged c044f3d836 ("jbd2: abort journal if free a async
write error metadata buffer"), there is a race between
jbd2_journal_try_to_free_buffers() and jbd2_journal_destroy(), so the
jbd2_log_do_checkpoint() may still fail to detect the buffer write
io error flag which may lead to filesystem inconsistency.

jbd2_journal_try_to_free_buffers()     ext4_put_super()
                                        jbd2_journal_destroy()
  __jbd2_journal_remove_checkpoint()
  detect buffer write error              jbd2_log_do_checkpoint()
                                         jbd2_cleanup_journal_tail()
                                           <--- lead to inconsistency
  jbd2_journal_abort()

Fix this issue by introducing a new atomic flag which only have one
JBD2_CHECKPOINT_IO_ERROR bit now, and set it in
__jbd2_journal_remove_checkpoint() when freeing a checkpoint buffer
which has write_io_error flag. Then jbd2_journal_destroy() will detect
this mark and abort the journal to prevent updating log tail.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210610112440.3438139-3-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-06-24 10:33:49 -04:00
Zhang Yi 1866cba842 jbd2: remove the out label in __jbd2_journal_remove_checkpoint()
The 'out' lable just return the 'ret' value and seems not required, so
remove this label and switch to return appropriate value immediately.
This patch also do some minor cleanup, no logical change.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210610112440.3438139-2-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-06-24 10:33:06 -04:00
yangerkun d07621d9b9 jbd2: clean up misleading comments for jbd2_fc_release_bufs
This comments was for jbd2_fc_wait_bufs, not for jbd2_fc_release_bufs.
Remove this misleading comments.

Signed-off-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210608141236.459441-1-yangerkun@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-06-24 10:27:32 -04:00
Leah Rumancik 01d5d96542 ext4: add discard/zeroout flags to journal flush
Add a flags argument to jbd2_journal_flush to enable discarding or
zero-filling the journal blocks while flushing the journal.

Signed-off-by: Leah Rumancik <leah.rumancik@gmail.com>
Link: https://lore.kernel.org/r/20210518151327.130198-1-leah.rumancik@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-06-22 19:27:10 -04:00
Arnd Bergmann fcdf3c34b7 ext4: fix debug format string warning
Using no_printk() for jbd_debug() revealed two warnings:

fs/jbd2/recovery.c: In function 'fc_do_one_pass':
fs/jbd2/recovery.c:256:30: error: format '%d' expects a matching 'int' argument [-Werror=format=]
  256 |                 jbd_debug(3, "Processing fast commit blk with seq %d");
      |                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/ext4/fast_commit.c: In function 'ext4_fc_replay_add_range':
fs/ext4/fast_commit.c:1732:30: error: format '%d' expects argument of type 'int', but argument 2 has type 'long unsigned int' [-Werror=format=]
 1732 |                 jbd_debug(1, "Converting from %d to %d %lld",

The first one was added incorrectly, and was also missing a few newlines
in debug output, and the second one happened when the type of an
argument changed.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: d556435156 ("jbd2: avoid -Wempty-body warnings")
Fixes: 6db0746189 ("ext4: use BIT() macro for BH_** state bits")
Fixes: 5b849b5f96 ("jbd2: fast commit recovery path")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20210409201211.1866633-1-arnd@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-04-09 23:32:16 -04:00
Jan Kara 83fe6b18b8 ext4: annotate data race in jbd2_journal_dirty_metadata()
Assertion checks in jbd2_journal_dirty_metadata() are known to be racy
but we don't want to be grabbing locks just for them.  We thus recheck
them under b_state_lock only if it looks like they would fail. Annotate
the checks with data_race().

Cc: stable@kernel.org
Reported-by: Hao Sun <sunhao.th@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210406161804.20150-2-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-04-09 21:19:33 -04:00
Jan Kara 3b1833e92b ext4: annotate data race in start_this_handle()
Access to journal->j_running_transaction is not protected by appropriate
lock and thus is racy. We are well aware of that and the code handles
the race properly. Just add a comment and data_race() annotation.

Cc: stable@kernel.org
Reported-by: syzbot+30774a6acf6a2cf6d535@syzkaller.appspotmail.com
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210406161804.20150-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-04-09 21:19:32 -04:00
Christoph Hellwig c6bf3f0e25 block: use an on-stack bio in blkdev_issue_flush
There is no point in allocating memory for a synchronous flush.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-27 09:51:48 -07:00
Harshad Shirwadkar 9bd23c31f3 jbd2: add a helper to find out number of fast commit blocks
Add a helper to read number of fast commit blocks from jbd2 superblock
and also rename the JBD2_MIN_FC_BLKS to
JBD2_DEFAULT_FAST_COMMIT_BLOCKS since this constant is just the
default number of fast commit blocks to use in case number of fast
commit blocks isn't set in jbd2 superblock.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201120202232.2240293-2-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-12-17 13:30:45 -05:00
Mauro Carvalho Chehab 2bf31d9442 jbd2: fix kernel-doc markups
Kernel-doc markup should use this format:
        identifier - description

They should not have any type before that, as otherwise
the parser won't do the right thing.

Also, some identifiers have different names between their
prototypes and the kernel-doc markup.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/72f5c6628f5f278d67625f60893ffbc2ca28d46e.1605521731.git.mchehab+huawei@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-11-19 22:38:29 -05:00
Theodore Ts'o 05d5233df8 jbd2: fix up sparse warnings in checkpoint code
Add missing __acquires() and __releases() annotations.  Also, in an
"this should never happen" WARN_ON check, if it *does* actually
happen, we need to release j_state_lock since this function is always
supposed to release that lock.  Otherwise, things will quickly grind
to a halt after the WARN_ON trips.

Fixes: 96f1e09745 ("jbd2: avoid long hold times of j_state_lock...")
Cc: stable@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-11-07 00:09:08 -05:00
Harshad Shirwadkar 87a144f093 jbd2: don't start fast commit on aborted journal
Fast commit should not be started if the journal is aborted.

Signed-off-by: Harshad Shirwadkar<harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-22-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-11-06 23:01:06 -05:00
Harshad Shirwadkar 480f89d553 jbd2: don't read journal->j_commit_sequence without taking a lock
Take journal state lock before reading journal->j_commit_sequence.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-13-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-11-06 23:01:04 -05:00
Harshad Shirwadkar 0ee66ddcf3 jbd2: don't touch buffer state until it is filled
Fast commit buffers should be filled in before toucing their
state. Remove code that sets buffer state as dirty before the buffer
is passed to the file system.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-12-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-11-06 23:01:04 -05:00
Harshad Shirwadkar cc80586a57 jbd2: add todo for a fast commit performance optimization
Fast commit performance can be optimized if commit thread doesn't wait
for ongoing fast commits to complete until the transaction enters
T_FLUSH state. Document this optimization.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-11-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-11-06 23:01:03 -05:00
Harshad Shirwadkar 0bce577bf9 jbd2: don't pass tid to jbd2_fc_end_commit_fallback()
In jbd2_fc_end_commit_fallback(), we know which tid to commit. There's
no need for caller to pass it.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-10-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-11-06 23:01:03 -05:00
Harshad Shirwadkar c460e5edc8 jbd2: don't use state lock during commit path
Variables journal->j_fc_off, journal->j_fc_wbuf are accessed during
commit path. Since today we allow only one process to perform a fast
commit, there is no need take state lock before accessing these
variables. This patch removes these locks and adds comments to
describe this.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-9-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-11-06 23:01:03 -05:00
Harshad Shirwadkar a1e5e465b3 ext4: clean up the JBD2 API that initializes fast commits
This patch removes jbd2_fc_init() API and its related functions to
simplify enabling fast commits. With this change, the number of fast
commit blocks to use is solely determined by the JBD2 layer. So, we
move the default value for minimum number of fast commit blocks from
ext4/fast_commit.h to include/linux/jbd2.h. However, whether or not to
use fast commits is determined by the file system. The file system
just sets the fast commit feature using
jbd2_journal_set_features(). JBD2 layer then determines how many
blocks to use for fast commits (based on the value found in the JBD2
superblock).

Note that the JBD2 feature flag of fast commits is just an indication
that there are fast commit blocks present on disk. It doesn't tell
JBD2 layer about the intent of the file system of whether to it wants
to use fast commit or not. That's why, we blindly clear the fast
commit flag in journal_reset() after the recovery is done.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-7-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-11-06 23:01:03 -05:00
Harshad Shirwadkar ede7dc7fa0 jbd2: rename j_maxlen to j_total_len and add jbd2_journal_max_txn_bufs
The on-disk superblock field sb->s_maxlen represents the total size of
the journal including the fast commit area and is no more the max
number of blocks available for a transaction. The maximum number of
blocks available to a transaction is reduced by the number of fast
commit blocks. So, this patch renames j_maxlen to j_total_len to
better represent its intent. Also, it adds a function to calculate max
number of bufs available for a transaction.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-6-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-11-06 23:01:02 -05:00
Harshad Shirwadkar 5b849b5f96 jbd2: fast commit recovery path
This patch adds fast commit recovery support in JBD2.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201015203802.3597742-7-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-21 23:22:37 -04:00
Harshad Shirwadkar ff780b91ef jbd2: add fast commit machinery
This functions adds necessary APIs needed in JBD2 layer for fast
commits.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201015203802.3597742-5-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-21 23:22:37 -04:00
Harshad Shirwadkar 6866d7b3f2 ext4 / jbd2: add fast commit initialization
This patch adds fast commit area trackers in the journal_t
structure. These are initialized via the jbd2_fc_init() routine that
this patch adds. This patch also adds ext4/fast_commit.c and
ext4/fast_commit.h files for fast commit code that will be added in
subsequent patches in this series.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201015203802.3597742-4-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-21 23:22:26 -04:00
changfengnan fc750a3b44 jbd2: avoid transaction reuse after reformatting
When ext4 is formatted with lazy_journal_init=1 and transactions from
the previous filesystem are still on disk, it is possible that they are
considered during a recovery after a crash. Because the checksum seed
has changed, the CRC check will fail, and the journal recovery fails
with checksum error although the journal is otherwise perfectly valid.
Fix the problem by checking commit block time stamps to determine
whether the data in the journal block is just stale or whether it is
indeed corrupt.

Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Fengnan Chang <changfengnan@hikvision.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20201012164900.20197-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18 10:37:26 -04:00
Mauricio Faria de Oliveira 342af94ec6 jbd2, ext4, ocfs2: introduce/use journal callbacks j_submit|finish_inode_data_buffers()
Introduce journal callbacks to allow different behaviors
for an inode in journal_submit|finish_inode_data_buffers().

The existing users of the current behavior (ext4, ocfs2)
are adapted to use the previously exported functions
that implement the current behavior.

Users are callers of jbd2_journal_inode_ranged_write|wait(),
which adds the inode to the transaction's inode list with
the JI_WRITE|WAIT_DATA flags. Only ext4 and ocfs2 in-tree.

Both CONFIG_EXT4_FS and CONFIG_OCSFS2_FS select CONFIG_JBD2,
which builds fs/jbd2/commit.c and journal.c that define and
export the functions, so we can call directly in ext4/ocfs2.

Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/20201006004841.600488-3-mfo@canonical.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18 10:37:15 -04:00
Mauricio Faria de Oliveira aa3c0c61f6 jbd2: introduce/export functions jbd2_journal_submit|finish_inode_data_buffers()
Export functions that implement the current behavior done
for an inode in journal_submit|finish_inode_data_buffers().

No functional change.

Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/20201006004841.600488-2-mfo@canonical.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18 10:37:15 -04:00
Shijie Luo 00a3fff071 jbd2: clean up checksum verification in do_one_pass()
Remove the unnecessary chksum_err and checksum_seen variables as well as
some redundant code to make the function easier to understand.

[ With changes suggested by jack@ and tytso@ ]

Signed-off-by: Shijie Luo <luoshijie1@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200819122955.33526-1-luoshijie1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-08-19 12:04:35 -04:00
Xianting Tian 60ed633f51 jbd2: fix incorrect code style
Remove unnecessary blank.

Signed-off-by: Xianting Tian <xianting_tian@126.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/1595077057-8048-1-git-send-email-xianting_tian@126.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-08-07 14:12:35 -04:00
zhangyi (F) 529a781ee0 jbd2: remove unused parameter in jbd2_journal_try_to_free_buffers()
Parameter gfp_mask in jbd2_journal_try_to_free_buffers() is no longer
used after commit <536fc240e7147> ("jbd2: clean up
jbd2_journal_try_to_free_buffers()"), so just remove it.

Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20200620025427.1756360-6-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-08-07 14:12:35 -04:00
zhangyi (F) c044f3d836 jbd2: abort journal if free a async write error metadata buffer
If we free a metadata buffer which has been failed to async write out
in the background, the jbd2 checkpoint procedure will not detect this
failure in jbd2_log_do_checkpoint(), so it may lead to filesystem
inconsistency after cleanup journal tail. This patch abort the journal
if free a buffer has write_io_error flag to prevent potential further
inconsistency.

Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20200620025427.1756360-5-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-08-07 14:12:34 -04:00
zhangyi (F) ef3f5830b8 jbd2: add the missing unlock_buffer() in the error path of jbd2_write_superblock()
jbd2_write_superblock() is under the buffer lock of journal superblock
before ending that superblock write, so add a missing unlock_buffer() in
in the error path before submitting buffer.

Fixes: 742b06b562 ("jbd2: check superblock mapped prior to committing")
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20200620061948.2049579-1-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-08-06 00:15:58 -04:00
Lukas Czerner 24dc986491 jbd2: make sure jh have b_transaction set in refile/unfile_buffer
Callers of __jbd2_journal_unfile_buffer() and
__jbd2_journal_refile_buffer() assume that the b_transaction is set. In
fact if it's not, we can end up with journal_head refcounting errors
leading to crash much later that might be very hard to track down. Add
asserts to make sure that is the case.

We also make sure that b_next_transaction is NULL in
__jbd2_journal_unfile_buffer() since the callers expect that as well and
we should not get into that stage in this state anyway, leading to
problems later on if we do.

Tested with fstests.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200617092549.6712-1-lczerner@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-08-06 00:11:15 -04:00
Linus Torvalds 3be20b6fc1 This is the second round of ext4 commits for 5.8 merge window. It
includes the per-inode DAX support, which was dependant on the DAX
 infrastructure which came in via the XFS tree, and a number of
 regression and bug fixes; most notably the "BUG: using
 smp_processor_id() in preemptible code in ext4_mb_new_blocks" reported
 by syzkaller.
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Merge tag 'ext4-for-linus-5.8-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull more ext4 updates from Ted Ts'o:
 "This is the second round of ext4 commits for 5.8 merge window [1].

  It includes the per-inode DAX support, which was dependant on the DAX
  infrastructure which came in via the XFS tree, and a number of
  regression and bug fixes; most notably the "BUG: using
  smp_processor_id() in preemptible code in ext4_mb_new_blocks" reported
  by syzkaller"

[1] The pull request actually came in 15 minutes after I had tagged the
    rc1 release. Tssk, tssk, late..   - Linus

* tag 'ext4-for-linus-5.8-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4, jbd2: ensure panic by fix a race between jbd2 abort and ext4 error handlers
  ext4: support xattr gnu.* namespace for the Hurd
  ext4: mballoc: Use this_cpu_read instead of this_cpu_ptr
  ext4: avoid utf8_strncasecmp() with unstable name
  ext4: stop overwrite the errcode in ext4_setup_super
  ext4: fix partial cluster initialization when splitting extent
  ext4: avoid race conditions when remounting with options that change dax
  Documentation/dax: Update DAX enablement for ext4
  fs/ext4: Introduce DAX inode flag
  fs/ext4: Remove jflag variable
  fs/ext4: Make DAX mount option a tri-state
  fs/ext4: Only change S_DAX on inode load
  fs/ext4: Update ext4_should_use_dax()
  fs/ext4: Change EXT4_MOUNT_DAX to EXT4_MOUNT_DAX_ALWAYS
  fs/ext4: Disallow verity if inode is DAX
  fs/ext4: Narrow scope of DAX check in setflags
2020-06-15 09:32:10 -07:00
zhangyi (F) 7b97d868b7 ext4, jbd2: ensure panic by fix a race between jbd2 abort and ext4 error handlers
In the ext4 filesystem with errors=panic, if one process is recording
errno in the superblock when invoking jbd2_journal_abort() due to some
error cases, it could be raced by another __ext4_abort() which is
setting the SB_RDONLY flag but missing panic because errno has not been
recorded.

jbd2_journal_commit_transaction()
 jbd2_journal_abort()
  journal->j_flags |= JBD2_ABORT;
  jbd2_journal_update_sb_errno()
                                    | ext4_journal_check_start()
                                    |  __ext4_abort()
                                    |   sb->s_flags |= SB_RDONLY;
                                    |   if (!JBD2_REC_ERR)
                                    |        return;
  journal->j_flags |= JBD2_REC_ERR;

Finally, it will no longer trigger panic because the filesystem has
already been set read-only. Fix this by introduce j_abort_mutex to make
sure journal abort is completed before panic, and remove JBD2_REC_ERR
flag.

Fixes: 4327ba52af ("ext4, jbd2: ensure entering into panic after recording an error in superblock")
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200609073540.3810702-1-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-12 14:51:41 -04:00
Linus Torvalds 0b166a57e6 A lot of bug fixes and cleanups for ext4, including:
* Fix performance problems found in dioread_nolock now that it is the
   default, caused by transaction leaks.
 * Clean up fiemap handling in ext4
 * Clean up and refactor multiple block allocator (mballoc) code
 * Fix a problem with mballoc with a smaller file systems running out
   of blocks because they couldn't properly use blocks that had been
   reserved by inode preallocation.
 * Fixed a race in ext4_sync_parent() versus rename()
 * Simplify the error handling in the extent manipulation code
 * Make sure all metadata I/O errors are felected to ext4_ext_dirty()'s and
   ext4_make_inode_dirty()'s callers.
 * Avoid passing an error pointer to brelse in ext4_xattr_set()
 * Fix race which could result to freeing an inode on the dirty last
   in data=journal mode.
 * Fix refcount handling if ext4_iget() fails
 * Fix a crash in generic/019 caused by a corrupted extent node
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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:
 "A lot of bug fixes and cleanups for ext4, including:

   - Fix performance problems found in dioread_nolock now that it is the
     default, caused by transaction leaks.

   - Clean up fiemap handling in ext4

   - Clean up and refactor multiple block allocator (mballoc) code

   - Fix a problem with mballoc with a smaller file systems running out
     of blocks because they couldn't properly use blocks that had been
     reserved by inode preallocation.

   - Fixed a race in ext4_sync_parent() versus rename()

   - Simplify the error handling in the extent manipulation code

   - Make sure all metadata I/O errors are felected to
     ext4_ext_dirty()'s and ext4_make_inode_dirty()'s callers.

   - Avoid passing an error pointer to brelse in ext4_xattr_set()

   - Fix race which could result to freeing an inode on the dirty last
     in data=journal mode.

   - Fix refcount handling if ext4_iget() fails

   - Fix a crash in generic/019 caused by a corrupted extent node"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (58 commits)
  ext4: avoid unnecessary transaction starts during writeback
  ext4: don't block for O_DIRECT if IOCB_NOWAIT is set
  ext4: remove the access_ok() check in ext4_ioctl_get_es_cache
  fs: remove the access_ok() check in ioctl_fiemap
  fs: handle FIEMAP_FLAG_SYNC in fiemap_prep
  fs: move fiemap range validation into the file systems instances
  iomap: fix the iomap_fiemap prototype
  fs: move the fiemap definitions out of fs.h
  fs: mark __generic_block_fiemap static
  ext4: remove the call to fiemap_check_flags in ext4_fiemap
  ext4: split _ext4_fiemap
  ext4: fix fiemap size checks for bitmap files
  ext4: fix EXT4_MAX_LOGICAL_BLOCK macro
  add comment for ext4_dir_entry_2 file_type member
  jbd2: avoid leaking transaction credits when unreserving handle
  ext4: drop ext4_journal_free_reserved()
  ext4: mballoc: use lock for checking free blocks while retrying
  ext4: mballoc: refactor ext4_mb_good_group()
  ext4: mballoc: introduce pcpu seqcnt for freeing PA to improve ENOSPC handling
  ext4: mballoc: refactor ext4_mb_discard_preallocations()
  ...
2020-06-05 16:19:28 -07:00
Jan Kara 14ff628630 jbd2: avoid leaking transaction credits when unreserving handle
When reserved transaction handle is unused, we subtract its reserved
credits in __jbd2_journal_unreserve_handle() called from
jbd2_journal_stop(). However this function forgets to remove reserved
credits from transaction->t_outstanding_credits and thus the transaction
space that was reserved remains effectively leaked. The leaked
transaction space can be quite significant in some cases and leads to
unnecessarily small transactions and thus reducing throughput of the
journalling machinery. E.g. fsmark workload creating lots of 4k files
was observed to have about 20% lower throughput due to this when ext4 is
mounted with dioread_nolock mount option.

Subtract reserved credits from t_outstanding_credits as well.

CC: stable@vger.kernel.org
Fixes: 8f7d89f368 ("jbd2: transaction reservation support")
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200520133119.1383-3-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03 23:16:53 -04:00
Christoph Hellwig 9398554fb3 block: remove the error_sector argument to blkdev_issue_flush
The argument isn't used by any caller, and drivers don't fill out
bi_sector for flush requests either.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-22 08:45:46 -06:00
zhangyi (F) 780f66e592 jbd2: improve comments about freeing data buffers whose page mapping is NULL
Improve comments in jbd2_journal_commit_transaction() to describe why
we don't need to clear the buffer_mapped bit for freeing file mapping
buffers whose page mapping is NULL.

Link: https://lore.kernel.org/r/20200217112706.20085-1-yi.zhang@huawei.com
Fixes: c96dceeabf ("jbd2: do not clear the BH_Mapped flag when forgetting a metadata buffer")
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-03-05 20:25:05 -05:00
Qian Cai 6c5d911249 jbd2: fix data races at struct journal_head
journal_head::b_transaction and journal_head::b_next_transaction could
be accessed concurrently as noticed by KCSAN,

 LTP: starting fsync04
 /dev/zero: Can't open blockdev
 EXT4-fs (loop0): mounting ext3 file system using the ext4 subsystem
 EXT4-fs (loop0): mounted filesystem with ordered data mode. Opts: (null)
 ==================================================================
 BUG: KCSAN: data-race in __jbd2_journal_refile_buffer [jbd2] / jbd2_write_access_granted [jbd2]

 write to 0xffff99f9b1bd0e30 of 8 bytes by task 25721 on cpu 70:
  __jbd2_journal_refile_buffer+0xdd/0x210 [jbd2]
  __jbd2_journal_refile_buffer at fs/jbd2/transaction.c:2569
  jbd2_journal_commit_transaction+0x2d15/0x3f20 [jbd2]
  (inlined by) jbd2_journal_commit_transaction at fs/jbd2/commit.c:1034
  kjournald2+0x13b/0x450 [jbd2]
  kthread+0x1cd/0x1f0
  ret_from_fork+0x27/0x50

 read to 0xffff99f9b1bd0e30 of 8 bytes by task 25724 on cpu 68:
  jbd2_write_access_granted+0x1b2/0x250 [jbd2]
  jbd2_write_access_granted at fs/jbd2/transaction.c:1155
  jbd2_journal_get_write_access+0x2c/0x60 [jbd2]
  __ext4_journal_get_write_access+0x50/0x90 [ext4]
  ext4_mb_mark_diskspace_used+0x158/0x620 [ext4]
  ext4_mb_new_blocks+0x54f/0xca0 [ext4]
  ext4_ind_map_blocks+0xc79/0x1b40 [ext4]
  ext4_map_blocks+0x3b4/0x950 [ext4]
  _ext4_get_block+0xfc/0x270 [ext4]
  ext4_get_block+0x3b/0x50 [ext4]
  __block_write_begin_int+0x22e/0xae0
  __block_write_begin+0x39/0x50
  ext4_write_begin+0x388/0xb50 [ext4]
  generic_perform_write+0x15d/0x290
  ext4_buffered_write_iter+0x11f/0x210 [ext4]
  ext4_file_write_iter+0xce/0x9e0 [ext4]
  new_sync_write+0x29c/0x3b0
  __vfs_write+0x92/0xa0
  vfs_write+0x103/0x260
  ksys_write+0x9d/0x130
  __x64_sys_write+0x4c/0x60
  do_syscall_64+0x91/0xb05
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 5 locks held by fsync04/25724:
  #0: ffff99f9911093f8 (sb_writers#13){.+.+}, at: vfs_write+0x21c/0x260
  #1: ffff99f9db4c0348 (&sb->s_type->i_mutex_key#15){+.+.}, at: ext4_buffered_write_iter+0x65/0x210 [ext4]
  #2: ffff99f5e7dfcf58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2]
  #3: ffff99f9db4c0168 (&ei->i_data_sem){++++}, at: ext4_map_blocks+0x176/0x950 [ext4]
  #4: ffffffff99086b40 (rcu_read_lock){....}, at: jbd2_write_access_granted+0x4e/0x250 [jbd2]
 irq event stamp: 1407125
 hardirqs last  enabled at (1407125): [<ffffffff980da9b7>] __find_get_block+0x107/0x790
 hardirqs last disabled at (1407124): [<ffffffff980da8f9>] __find_get_block+0x49/0x790
 softirqs last  enabled at (1405528): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c
 softirqs last disabled at (1405521): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 68 PID: 25724 Comm: fsync04 Tainted: G L 5.6.0-rc2-next-20200221+ #7
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

The plain reads are outside of jh->b_state_lock critical section which result
in data races. Fix them by adding pairs of READ|WRITE_ONCE().

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Qian Cai <cai@lca.pw>
Link: https://lore.kernel.org/r/20200222043111.2227-1-cai@lca.pw
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-02-29 13:40:02 -05:00
wangyan 8eedabfd66 jbd2: fix ocfs2 corrupt when clearing block group bits
I found a NULL pointer dereference in ocfs2_block_group_clear_bits().
The running environment:
	kernel version: 4.19
	A cluster with two nodes, 5 luns mounted on two nodes, and do some
	file operations like dd/fallocate/truncate/rm on every lun with storage
	network disconnection.

The fallocate operation on dm-23-45 caused an null pointer dereference.

The information of NULL pointer dereference as follows:
	[577992.878282] JBD2: Error -5 detected when updating journal superblock for dm-23-45.
	[577992.878290] Aborting journal on device dm-23-45.
	...
	[577992.890778] JBD2: Error -5 detected when updating journal superblock for dm-24-46.
	[577992.890908] __journal_remove_journal_head: freeing b_committed_data
	[577992.890916] (fallocate,88392,52):ocfs2_extend_trans:474 ERROR: status = -30
	[577992.890918] __journal_remove_journal_head: freeing b_committed_data
	[577992.890920] (fallocate,88392,52):ocfs2_rotate_tree_right:2500 ERROR: status = -30
	[577992.890922] __journal_remove_journal_head: freeing b_committed_data
	[577992.890924] (fallocate,88392,52):ocfs2_do_insert_extent:4382 ERROR: status = -30
	[577992.890928] (fallocate,88392,52):ocfs2_insert_extent:4842 ERROR: status = -30
	[577992.890928] __journal_remove_journal_head: freeing b_committed_data
	[577992.890930] (fallocate,88392,52):ocfs2_add_clusters_in_btree:4947 ERROR: status = -30
	[577992.890933] __journal_remove_journal_head: freeing b_committed_data
	[577992.890939] __journal_remove_journal_head: freeing b_committed_data
	[577992.890949] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
	[577992.890950] Mem abort info:
	[577992.890951]   ESR = 0x96000004
	[577992.890952]   Exception class = DABT (current EL), IL = 32 bits
	[577992.890952]   SET = 0, FnV = 0
	[577992.890953]   EA = 0, S1PTW = 0
	[577992.890954] Data abort info:
	[577992.890955]   ISV = 0, ISS = 0x00000004
	[577992.890956]   CM = 0, WnR = 0
	[577992.890958] user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000f8da07a9
	[577992.890960] [0000000000000020] pgd=0000000000000000
	[577992.890964] Internal error: Oops: 96000004 [#1] SMP
	[577992.890965] Process fallocate (pid: 88392, stack limit = 0x00000000013db2fd)
	[577992.890968] CPU: 52 PID: 88392 Comm: fallocate Kdump: loaded Tainted: G        W  OE     4.19.36 #1
	[577992.890969] Hardware name: Huawei TaiShan 2280 V2/BC82AMDD, BIOS 0.98 08/25/2019
	[577992.890971] pstate: 60400009 (nZCv daif +PAN -UAO)
	[577992.891054] pc : _ocfs2_free_suballoc_bits+0x63c/0x968 [ocfs2]
	[577992.891082] lr : _ocfs2_free_suballoc_bits+0x618/0x968 [ocfs2]
	[577992.891084] sp : ffff0000c8e2b810
	[577992.891085] x29: ffff0000c8e2b820 x28: 0000000000000000
	[577992.891087] x27: 00000000000006f3 x26: ffffa07957b02e70
	[577992.891089] x25: ffff807c59d50000 x24: 00000000000006f2
	[577992.891091] x23: 0000000000000001 x22: ffff807bd39abc30
	[577992.891093] x21: ffff0000811d9000 x20: ffffa07535d6a000
	[577992.891097] x19: ffff000001681638 x18: ffffffffffffffff
	[577992.891098] x17: 0000000000000000 x16: ffff000080a03df0
	[577992.891100] x15: ffff0000811d9708 x14: 203d207375746174
	[577992.891101] x13: 73203a524f525245 x12: 20373439343a6565
	[577992.891103] x11: 0000000000000038 x10: 0101010101010101
	[577992.891106] x9 : ffffa07c68a85d70 x8 : 7f7f7f7f7f7f7f7f
	[577992.891109] x7 : 0000000000000000 x6 : 0000000000000080
	[577992.891110] x5 : 0000000000000000 x4 : 0000000000000002
	[577992.891112] x3 : ffff000001713390 x2 : 2ff90f88b1c22f00
	[577992.891114] x1 : ffff807bd39abc30 x0 : 0000000000000000
	[577992.891116] Call trace:
	[577992.891139]  _ocfs2_free_suballoc_bits+0x63c/0x968 [ocfs2]
	[577992.891162]  _ocfs2_free_clusters+0x100/0x290 [ocfs2]
	[577992.891185]  ocfs2_free_clusters+0x50/0x68 [ocfs2]
	[577992.891206]  ocfs2_add_clusters_in_btree+0x198/0x5e0 [ocfs2]
	[577992.891227]  ocfs2_add_inode_data+0x94/0xc8 [ocfs2]
	[577992.891248]  ocfs2_extend_allocation+0x1bc/0x7a8 [ocfs2]
	[577992.891269]  ocfs2_allocate_extents+0x14c/0x338 [ocfs2]
	[577992.891290]  __ocfs2_change_file_space+0x3f8/0x610 [ocfs2]
	[577992.891309]  ocfs2_fallocate+0xe4/0x128 [ocfs2]
	[577992.891316]  vfs_fallocate+0x11c/0x250
	[577992.891317]  ksys_fallocate+0x54/0x88
	[577992.891319]  __arm64_sys_fallocate+0x28/0x38
	[577992.891323]  el0_svc_common+0x78/0x130
	[577992.891325]  el0_svc_handler+0x38/0x78
	[577992.891327]  el0_svc+0x8/0xc

My analysis process as follows:
ocfs2_fallocate
  __ocfs2_change_file_space
    ocfs2_allocate_extents
      ocfs2_extend_allocation
        ocfs2_add_inode_data
          ocfs2_add_clusters_in_btree
            ocfs2_insert_extent
              ocfs2_do_insert_extent
                ocfs2_rotate_tree_right
                  ocfs2_extend_rotate_transaction
                    ocfs2_extend_trans
                      jbd2_journal_restart
                        jbd2__journal_restart
                          /* handle->h_transaction is NULL,
                           * is_handle_aborted(handle) is true
                           */
                          handle->h_transaction = NULL;
                          start_this_handle
                            return -EROFS;
            ocfs2_free_clusters
              _ocfs2_free_clusters
                _ocfs2_free_suballoc_bits
                  ocfs2_block_group_clear_bits
                    ocfs2_journal_access_gd
                      __ocfs2_journal_access
                        jbd2_journal_get_undo_access
                          /* I think jbd2_write_access_granted() will
                           * return true, because do_get_write_access()
                           * will return -EROFS.
                           */
                          if (jbd2_write_access_granted(...)) return 0;
                          do_get_write_access
                            /* handle->h_transaction is NULL, it will
                             * return -EROFS here, so do_get_write_access()
                             * was not called.
                             */
                            if (is_handle_aborted(handle)) return -EROFS;
                    /* bh2jh(group_bh) is NULL, caused NULL
                       pointer dereference */
                    undo_bg = (struct ocfs2_group_desc *)
                                bh2jh(group_bh)->b_committed_data;

If handle->h_transaction == NULL, then jbd2_write_access_granted()
does not really guarantee that journal_head will stay around,
not even speaking of its b_committed_data. The bh2jh(group_bh)
can be removed after ocfs2_journal_access_gd() and before call
"bh2jh(group_bh)->b_committed_data". So, we should move
is_handle_aborted() check from do_get_write_access() into
jbd2_journal_get_undo_access() and jbd2_journal_get_write_access()
before the call to jbd2_write_access_granted().

Link: https://lore.kernel.org/r/f72a623f-b3f1-381a-d91d-d22a1c83a336@huawei.com
Signed-off-by: Yan Wang <wangyan122@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jun Piao <piaojun@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org
2020-02-21 19:32:07 -05:00