From 169f1a2a87aae44034da4b9f81be1683d33de6d0 Mon Sep 17 00:00:00 2001 From: Paul Gortmaker Date: Wed, 12 Jun 2013 23:04:04 -0400 Subject: 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 Suggested-by: "Theodore Ts'o" Signed-off-by: Paul Gortmaker Signed-off-by: "Theodore Ts'o" --- include/linux/jbd2.h | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) (limited to 'include/linux') diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index 25d9c9ea7a14..0302f3f14063 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -56,17 +56,13 @@ */ #define JBD2_EXPENSIVE_CHECKING extern ushort jbd2_journal_enable_debug; +void __jbd2_debug(int level, const char *file, const char *func, + unsigned int line, const char *fmt, ...); -#define jbd_debug(n, f, a...) \ - do { \ - if ((n) <= jbd2_journal_enable_debug) { \ - printk (KERN_DEBUG "(%s, %d): %s: ", \ - __FILE__, __LINE__, __func__); \ - printk (f, ## a); \ - } \ - } while (0) +#define jbd_debug(n, fmt, a...) \ + __jbd2_debug((n), __FILE__, __func__, __LINE__, (fmt), ##a) #else -#define jbd_debug(f, a...) /**/ +#define jbd_debug(n, fmt, a...) /**/ #endif extern void *jbd2_alloc(size_t size, gfp_t flags); -- cgit v1.2.3-59-g8ed1b