When remounting ext4 from ro to rw, currently it allows its transition,
even if ext4_commit_super() returns EIO. Even worse thing is, after that,
fs/buffer complains buffer dirty bits like:
Call trace:
[<ffffff9750c259dc>] mark_buffer_dirty+0x184/0x1a4
[<ffffff9750cb398c>] __ext4_handle_dirty_super+0x4c/0xfc
[<ffffff9750c7a9fc>] ext4_file_open+0x154/0x1c0
[<ffffff9750bea51c>] do_dentry_open+0x114/0x2d0
[<ffffff9750bea75c>] vfs_open+0x5c/0x94
[<ffffff9750bf879c>] path_openat+0x668/0xfe8
[<ffffff9750bf8088>] do_filp_open+0x74/0x120
[<ffffff9750beac98>] do_sys_open+0x148/0x254
[<ffffff9750beade0>] SyS_openat+0x10/0x18
[<ffffff9750a83ab0>] el0_svc_naked+0x24/0x28
EXT4-fs (dm-1): previous I/O error to superblock detected
Buffer I/O error on dev dm-1, logical block 0, lost sync page write
EXT4-fs (dm-1): re-mounted. Opts: (null)
Buffer I/O error on dev dm-1, logical block 80, lost async page write
Cc: "Theodore Ts'o" <tytso@xxxxxxx>
Cc: Andreas Dilger <adilger.kernel@xxxxxxxxx>
Cc: linux-ext4@xxxxxxxxxxxxxxx
Cc: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
Change log from v1:
- modify return value of ext4_setup_super
- change the error handling order in ext4_commit_super
fs/ext4/super.c | 28 +++++++++++++++-------------
1 file changed, 15 insertions(+), 13 deletions(-)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 185f7e61f4cf..af4d373aa3ed 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2116,12 +2116,12 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
int read_only)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
- int res = 0;
+ int err = 0;
if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
ext4_msg(sb, KERN_ERR, "revision level too high, "
"forcing read-only mode");
- res = SB_RDONLY;
+ err = -EROFS;
}
if (read_only)
goto done;
@@ -2154,7 +2154,7 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
if (sbi->s_journal)
ext4_set_feature_journal_needs_recovery(sb);
- ext4_commit_super(sb, 1);
+ err = ext4_commit_super(sb, 1);
done:
if (test_opt(sb, DEBUG))
printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
@@ -2166,7 +2166,7 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
sbi->s_mount_opt, sbi->s_mount_opt2);
cleancache_init_fs(sb);
- return res;
+ return err;
}
int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
@@ -4760,11 +4760,7 @@ static int ext4_commit_super(struct super_block *sb, int sync)
unlock_buffer(sbh);
error = __sync_dirty_buffer(sbh,
REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
- if (error)
- return error;
-
- error = buffer_write_io_error(sbh);
- if (error) {
+ if (buffer_write_io_error(sbh)) {
ext4_msg(sb, KERN_ERR, "I/O error while writing "
"superblock");
clear_buffer_write_io_error(sbh);
@@ -5165,8 +5161,12 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
if (sbi->s_journal)
ext4_clear_journal_err(sb, es);
sbi->s_mount_state = le16_to_cpu(es->s_state);
- if (!ext4_setup_super(sb, es, 0))
- sb->s_flags &= ~SB_RDONLY;
+
+ err = ext4_setup_super(sb, es, 0);
+ if (err)
+ goto restore_opts;
+
+ sb->s_flags &= ~SB_RDONLY;
if (ext4_has_feature_mmp(sb))
if (ext4_multi_mount_protect(sb,
le64_to_cpu(es->s_mmp_block))) {
@@ -5190,8 +5190,10 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
}
ext4_setup_system_zone(sb);
- if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY))
- ext4_commit_super(sb, 1);
+ if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
+ err = ext4_commit_super(sb, 1);
+ goto restore_opts;
+ }
#ifdef CONFIG_QUOTA
/* Release old quota file names */
--
2.17.0.484.g0c8726318c-goog
