From: Jan Kara <jack@suse.cz>
To: <linux-ext4@vger.kernel.org>
Cc: Ted Tso <tytso@mit.edu>, Jan Kara <jack@suse.cz>, stable@vger.kernel.org
Subject: [PATCH 01/19] jbd2: Fix possible overflow in jbd2_log_space_left()
Date: Mon, 30 Sep 2019 12:43:19 +0200 [thread overview]
Message-ID: <20190930104339.24919-1-jack@suse.cz> (raw)
In-Reply-To: <20190930103544.11479-1-jack@suse.cz>
When number of free space in the journal is very low, the arithmetic in
jbd2_log_space_left() could underflow resulting in very high number of
free blocks and thus triggering assertion failure in transaction commit
code complaining there's not enough space in the journal:
J_ASSERT(journal->j_free > 1);
Properly check for the low number of free blocks.
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
---
include/linux/jbd2.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index df03825ad1a1..b20ef2c0812d 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -1584,7 +1584,7 @@ static inline int jbd2_space_needed(journal_t *journal)
static inline unsigned long jbd2_log_space_left(journal_t *journal)
{
/* Allow for rounding errors */
- unsigned long free = journal->j_free - 32;
+ long free = journal->j_free - 32;
if (journal->j_committing_transaction) {
unsigned long committing = atomic_read(&journal->
@@ -1593,7 +1593,7 @@ static inline unsigned long jbd2_log_space_left(journal_t *journal)
/* Transaction + control blocks */
free -= committing + (committing >> JBD2_CONTROL_BLOCKS_SHIFT);
}
- return free;
+ return max_t(long, free, 0);
}
/*
--
2.16.4
next prev parent reply other threads:[~2019-09-30 10:43 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-30 10:43 [PATCH 0/19 v2] ext4: Fix transaction overflow due to revoke descriptors Jan Kara
2019-09-30 10:43 ` Jan Kara [this message]
2019-09-30 10:43 ` [PATCH 02/19] jbd2: Fixup stale comment in commit code Jan Kara
2019-09-30 10:43 ` [PATCH 03/19] ext4: Do not iput inode under running transaction in ext4_mkdir() Jan Kara
2019-09-30 10:43 ` [PATCH 04/19] ext4: Use ext4_journal_extend() instead of jbd2_journal_extend() Jan Kara
2019-09-30 10:43 ` [PATCH 05/19] ext4: Avoid unnecessary revokes in ext4_alloc_branch() Jan Kara
2019-09-30 10:43 ` [PATCH 06/19] ext4: Provide function to handle transaction restarts Jan Kara
2019-09-30 10:43 ` [PATCH 07/19] ext4, jbd2: Provide accessor function for handle credits Jan Kara
2019-09-30 10:43 ` [PATCH 08/19] ocfs2: Use accessor function for h_buffer_credits Jan Kara
2019-09-30 10:43 ` [PATCH 09/19] jbd2: Fix statistics for the number of logged blocks Jan Kara
2019-09-30 10:43 ` [PATCH 10/19] jbd2: Reorganize jbd2_journal_stop() Jan Kara
2019-09-30 10:43 ` [PATCH 11/19] jbd2: Drop pointless check from jbd2_journal_stop() Jan Kara
2019-09-30 10:43 ` [PATCH 12/19] jbd2: Drop pointless wakeup " Jan Kara
2019-09-30 10:43 ` [PATCH 13/19] jbd2: Factor out common parts of stopping and restarting a handle Jan Kara
2019-09-30 10:43 ` [PATCH 14/19] jbd2: Account descriptor blocks into t_outstanding_credits Jan Kara
2019-09-30 10:43 ` [PATCH 15/19] jbd2: Drop jbd2_space_needed() Jan Kara
2019-09-30 10:43 ` [PATCH 16/19] jbd2: Reserve space for revoke descriptor blocks Jan Kara
2019-09-30 12:24 ` kbuild test robot
2019-09-30 10:43 ` [PATCH 17/19] jbd2: Rename h_buffer_credits to h_total_credits Jan Kara
2019-09-30 11:27 ` kbuild test robot
2019-09-30 12:26 ` kbuild test robot
2019-09-30 15:05 ` Theodore Y. Ts'o
2019-09-30 16:25 ` Jan Kara
2019-09-30 21:21 ` Theodore Y. Ts'o
2019-10-01 7:59 ` Jan Kara
2019-10-03 8:33 ` Jan Kara
2019-10-03 13:29 ` Theodore Y. Ts'o
2019-10-03 21:50 ` Jan Kara
2019-09-30 10:43 ` [PATCH 18/19] jbd2: Make credit checking more strict Jan Kara
2019-09-30 10:43 ` [PATCH 19/19] ext4: Reserve revoke credits for freed blocks Jan Kara
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