linux-stable/fs/jbd
Paul Gortmaker e99a03c6f5 jbd: use a single printk for jbd_debug()
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>
2013-08-09 10:49:00 +02:00
..
checkpoint.c jbd: Write journal superblock with WRITE_FUA after checkpointing 2012-05-15 23:34:37 +02:00
commit.c jbd: relocate assert after state lock in journal_commit_transaction() 2013-08-01 23:25:38 +02:00
journal.c jbd: use a single printk for jbd_debug() 2013-08-09 10:49:00 +02:00
Kconfig Revert "task_struct: make journal_info conditional" 2009-12-17 13:23:24 -08:00
Makefile
recovery.c jbd: Check return value of blkdev_issue_flush() 2012-07-09 23:38:36 +02:00
revoke.c jbd: clear revoked flag on buffers before a new transaction started 2011-11-22 01:20:53 +01:00
transaction.c jbd: change journal_invalidatepage() to accept length 2013-05-21 23:26:36 -04:00