Re: [PATCH] JFS: always load filesystem UUID during mount

[Dave Kleikamp <dave.kleikamp@oracle.com>]

On 3/1/26 8:55PM, João Paredes wrote:
> The filesystem UUID was only being loaded into super_block sb when an
> external journal device was in use. When mounting without an external
> journal, the UUID remained unset, which prevented the computation of
> a filesystem ID (fsid), which could be confirmed via `stat -f -c "%i"`
> and thus user space could not use fanotify correctly.
> 
> A missing filesystem ID causes fanotify to return ENODEV when marking
> the filesystem for events like FAN_CREATE, FAN_DELETE, FAN_MOVED_TO,
> and FAN_MOVED_FROM. As a result, applications relying on fanotify
> could not monitor these events on JFS filesystems without an external
> journal.
> 
> Moved the UUID initialization so it is always performed during mount,
> ensuring the superblock UUID is consistently available.
> 
> Signed-off-by: João Paredes <joaommp@yahoo.com>

Applied to jfs-next.

Thanks!
Shaggy

> ---
>   fs/jfs/jfs_mount.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/jfs/jfs_mount.c b/fs/jfs/jfs_mount.c
> index 52e6b58c5dbd..dac822f15070 100644
> --- a/fs/jfs/jfs_mount.c
> +++ b/fs/jfs/jfs_mount.c
> @@ -378,11 +378,12 @@ static int chkSuper(struct super_block *sb)
>   	sbi->nbperpage = PSIZE >> sbi->l2bsize;
>   	sbi->l2nbperpage = L2PSIZE - sbi->l2bsize;
>   	sbi->l2niperblk = sbi->l2bsize - L2DISIZE;
> +	uuid_copy(&sbi->uuid, &j_sb->s_uuid);
> +
>   	if (sbi->mntflag & JFS_INLINELOG)
>   		sbi->logpxd = j_sb->s_logpxd;
>   	else {
>   		sbi->logdev = new_decode_dev(le32_to_cpu(j_sb->s_logdev));
> -		uuid_copy(&sbi->uuid, &j_sb->s_uuid);
>   		uuid_copy(&sbi->loguuid, &j_sb->s_loguuid);
>   	}
>   	sbi->fsckpxd = j_sb->s_fsckpxd;