linux/fs/jbd2
Paul Gortmaker 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.

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>
2013-06-12 23:04:04 -04:00
..
checkpoint.c jbd2: drop checkpoint mutex when waiting in __jbd2_log_wait_for_space() 2013-06-12 22:47:35 -04:00
commit.c jbd2: fix duplicate debug label for phase 2 2013-06-12 22:56:35 -04:00
journal.c jbd2: use a single printk for jbd_debug() 2013-06-12 23:04:04 -04:00
Kconfig jbd2: Grab a reference to the crc32c driver if necessary 2012-05-27 07:50:56 -04:00
Makefile
recovery.c jbd2: fix block tag checksum verification brokenness 2013-05-28 07:31:59 -04:00
revoke.c jbd2: remove journal_head from descriptor buffers 2013-06-04 12:06:01 -04:00
transaction.c jbd2: optimize jbd2_journal_force_commit 2013-06-12 22:24:07 -04:00