diff options
| author | zhangyi (F) <yi.zhang@huawei.com> | 2020-06-09 15:35:40 +0800 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2020-06-12 14:51:41 -0400 |
| commit | 7b97d868b7ab2448859668de9222b8af43f76e78 (patch) | |
| tree | 976e49fc89eb8cd37e653d27192d9cb5289ed884 /fs/ext4 | |
| parent | 88ee9d571b6d8ed345f877e05f685814412e359b (diff) | |
| download | linux-7b97d868b7ab2448859668de9222b8af43f76e78.tar.bz2 | |
ext4, jbd2: ensure panic by fix a race between jbd2 abort and ext4 error handlers
In the ext4 filesystem with errors=panic, if one process is recording
errno in the superblock when invoking jbd2_journal_abort() due to some
error cases, it could be raced by another __ext4_abort() which is
setting the SB_RDONLY flag but missing panic because errno has not been
recorded.
jbd2_journal_commit_transaction()
jbd2_journal_abort()
journal->j_flags |= JBD2_ABORT;
jbd2_journal_update_sb_errno()
| ext4_journal_check_start()
| __ext4_abort()
| sb->s_flags |= SB_RDONLY;
| if (!JBD2_REC_ERR)
| return;
journal->j_flags |= JBD2_REC_ERR;
Finally, it will no longer trigger panic because the filesystem has
already been set read-only. Fix this by introduce j_abort_mutex to make
sure journal abort is completed before panic, and remove JBD2_REC_ERR
flag.
Fixes: 4327ba52afd03 ("ext4, jbd2: ensure entering into panic after recording an error in superblock")
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200609073540.3810702-1-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/super.c | 16 |
1 files changed, 5 insertions, 11 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 127b8efa8d54..2660a7e47eef 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -522,9 +522,6 @@ static void ext4_handle_error(struct super_block *sb) smp_wmb(); sb->s_flags |= SB_RDONLY; } else if (test_opt(sb, ERRORS_PANIC)) { - if (EXT4_SB(sb)->s_journal && - !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR)) - return; panic("EXT4-fs (device %s): panic forced after error\n", sb->s_id); } @@ -725,23 +722,20 @@ void __ext4_abort(struct super_block *sb, const char *function, va_end(args); if (sb_rdonly(sb) == 0) { - ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only"); EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED; + if (EXT4_SB(sb)->s_journal) + jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO); + + ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only"); /* * Make sure updated value of ->s_mount_flags will be visible * before ->s_flags update */ smp_wmb(); sb->s_flags |= SB_RDONLY; - if (EXT4_SB(sb)->s_journal) - jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO); } - if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) { - if (EXT4_SB(sb)->s_journal && - !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR)) - return; + if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) panic("EXT4-fs panic from previous error\n"); - } } void __ext4_msg(struct super_block *sb, |