Re: [PATCH 2/7] ext4: add EXT4_FLAGS_EMERGENCY_RO bit

From: Jan Kara
Date: Tue Jan 21 2025 - 07:08:24 EST


On Fri 17-01-25 16:23:10, libaokun@xxxxxxxxxxxxxxx wrote:
> From: Baokun Li <libaokun1@xxxxxxxxxx>
>
> EXT4_FLAGS_EMERGENCY_RO Indicates that the current file system has become
> read-only due to some error. Compared to SB_RDONLY, setting it does not
> require a lock because we won't clear it, which avoids over-coupling with
> vfs freeze. Also, add a helper function ext4_emergency_ro() to check if
> the bit is set.
>
> Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>

The same comment about comma after the last enum member. Otherwise looks
good. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

Honza

> ---
> fs/ext4/ext4.h | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index 612208527512..c5b775482897 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -2235,7 +2235,8 @@ extern int ext4_feature_set_ok(struct super_block *sb, int readonly);
> enum {
> EXT4_FLAGS_RESIZING, /* Avoid superblock update and resize race */
> EXT4_FLAGS_SHUTDOWN, /* Prevent access to the file system */
> - EXT4_FLAGS_BDEV_IS_DAX /* Current block device support DAX */
> + EXT4_FLAGS_BDEV_IS_DAX, /* Current block device support DAX */
> + EXT4_FLAGS_EMERGENCY_RO /* Emergency read-only due to fs errors */
> };
>
> static inline int ext4_forced_shutdown(struct super_block *sb)
> @@ -2243,6 +2244,11 @@ static inline int ext4_forced_shutdown(struct super_block *sb)
> return test_bit(EXT4_FLAGS_SHUTDOWN, &EXT4_SB(sb)->s_ext4_flags);
> }
>
> +static inline int ext4_emergency_ro(struct super_block *sb)
> +{
> + return test_bit(EXT4_FLAGS_EMERGENCY_RO, &EXT4_SB(sb)->s_ext4_flags);
> +}
> +
> /*
> * Default values for user and/or group using reserved blocks
> */
> --
> 2.39.2
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR