linux-stable.git/include/linux/jbd2.h, branch v3.4.112

jbd2: avoid infinite loop when destroying aborted journal

2015-10-22T01:20:08+00:00

commit 841df7df196237ea63233f0f9eaa41db53afd70f upstream.

Commit 6f6a6fda2945 "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 
Tested-by: Eryu Guan 
Fixes: 6f6a6fda294506dfe0e3e0a253bb2d2923f28f0a
Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o 
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li

jbd2: fix ocfs2 corrupt when updating journal superblock fails

2015-10-22T01:20:04+00:00

commit 6f6a6fda294506dfe0e3e0a253bb2d2923f28f0a upstream.

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.html
http://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 
Signed-off-by: Joseph Qi 
Signed-off-by: Theodore Ts'o 
Tested-by: Yiwen Jiang 
Cc: Junxiao Bi 
Signed-off-by: Zefan Li

ext4/jbd2: don't wait (forever) for stale tid caused by wraparound

2014-03-11T23:10:05+00:00

commit d76a3a77113db020d9bb1e894822869410450bd9 upstream.

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" 
Reported-by: Ben Hutchings 
Reported-by: George Barnett 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings 
Cc: Rui Xiang 
Signed-off-by: Greg Kroah-Hartman

jbd2: fix race between jbd2_journal_remove_checkpoint and ->j_commit_callback

2013-05-08T02:51:57+00:00

commit 794446c6946513c684d448205fbd76fa35f38b72 upstream.

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:
 [] warn_slowpath_common+0xad/0xf0
 [] warn_slowpath_fmt+0x46/0x50
 [] ? ext4_journal_commit_callback+0x99/0xc0
 [] __list_del_entry+0x1c0/0x250
 [] ext4_journal_commit_callback+0x6f/0xc0
 [] jbd2_journal_commit_transaction+0x23a6/0x2570
 [] ? try_to_del_timer_sync+0x82/0xa0
 [] ? del_timer_sync+0x91/0x1e0
 [] kjournald2+0x19f/0x6a0
 [] ? wake_up_bit+0x40/0x40
 [] ? bit_spin_lock+0x80/0x80
 [] kthread+0x10e/0x120
 [] ? __init_kthread_worker+0x70/0x70
 [] ret_from_fork+0x7c/0xb0
 [] ? __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 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman

ext4: make sure the journal sb is written in ext4_clear_journal_err()

2012-08-26T22:00:42+00:00

commit d796c52ef0b71a988364f6109aeb63d79c5b116b upstream.

After we transfer set the EXT4_ERROR_FS bit in the file system
superblock, it's not enough to call jbd2_journal_clear_err() to clear
the error indication from journal superblock --- we need to call
jbd2_journal_update_sb_errno() as well.  Otherwise, when the root file
system is mounted read-only, the journal is replayed, and the error
indicator is transferred to the superblock --- but the s_errno field
in the jbd2 superblock is left set (since although we cleared it in
memory, we never flushed it out to disk).

This can end up confusing e2fsck.  We should make e2fsck more robust
in this case, but the kernel shouldn't be leaving things in this
confused state, either.

Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman

jbd2: cleanup journal tail after transaction commit

2012-03-14T02:45:38+00:00

Normally, we have to issue a cache flush before we can update journal tail in
journal superblock, effectively wiping out old transactions from the journal.
So use the fact that during transaction commit we issue cache flush anyway and
opportunistically push journal tail as far as we can. Since update of journal
superblock is still costly (we have to use WRITE_FUA), we update log tail only
if we can free significant amount of space.

Signed-off-by: Jan Kara 
Signed-off-by: "Theodore Ts'o"

jbd2: issue cache flush after checkpointing even with internal journal

2012-03-14T02:22:54+00:00

When we reach jbd2_cleanup_journal_tail(), there is no guarantee that
checkpointed buffers are on a stable storage - especially if buffers were
written out by jbd2_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. Thus we must unconditionally issue a cache flush before we
update journal superblock in these cases.

A similar problem can also occur if journal superblock is written only in
disk's caches, other transaction starts reusing space of the transaction
cleaned from the log and power failure happens. 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 
Signed-off-by: "Theodore Ts'o"

jbd2: split updating of journal superblock and marking journal empty

2012-03-13T19:41:04+00:00

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 
Signed-off-by: "Theodore Ts'o"

jbd2: allocate transaction from separate slab cache

2012-02-20T22:53:02+00:00

There is normally only a handful of these active at any one time, but
putting them in a separate slab cache makes debugging memory
corruption problems easier.  Manish Katiyar also wanted this make it
easier to test memory failure scenarios in the jbd2 layer.

Cc: Manish Katiyar 
Signed-off-by: Yongqiang Yang 
Signed-off-by: "Theodore Ts'o"

jbd2: clear revoked flag on buffers before a new transaction started

2011-12-28T22:46:46+00:00

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 
Signed-off-by: "Theodore Ts'o"