ext4: do not commit super on read-only bdev

[ Upstream commit c96e2b8564adfb8ac14469ebc51ddc1bfecb3ae2 ]

Under some circumstances we may encounter a filesystem error on a
read-only block device, and if we try to save the error info to the
superblock and commit it, we'll wind up with a noisy error and
backtrace, i.e.:

[ 3337.146838] EXT4-fs error (device pmem1p2): ext4_get_journal_inode:4634: comm mount: inode #0: comm mount: iget: illegal inode #
------------[ cut here ]------------
generic_make_request: Trying to write to read-only block-device pmem1p2 (partno 2)
WARNING: CPU: 107 PID: 115347 at block/blk-core.c:788 generic_make_request_checks+0x6b4/0x7d0
...

To avoid this, commit the error info in the superblock only if the
block device is writable.

Reported-by: Ritesh Harjani <[email protected]>
Signed-off-by: Eric Sandeen <[email protected]>
Reviewed-by: Andreas Dilger <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
This commit is contained in:
Eric Sandeen 2020-03-18 14:19:38 -05:00 • committed by Greg Kroah-Hartman
commit b9f88c31b2

View file

@ -389,7 +389,8 @@ static void save_error_info(struct super_block *sb, const char *func,
unsigned int line)
{
__save_error_info(sb, func, line);
ext4_commit_super(sb, 1);
if (!bdev_read_only(sb->s_bdev))
ext4_commit_super(sb, 1);
}
/*