On Fri, 2018-03-02 at 10:51 -0600, Eric Sandeen wrote:
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>
>
> If mount is auto-probing for filesystem type, it will try various
> filesystems in order, with the MS_SILENT flag set. We get
> that flag as the silent arg to ext4_fill_super.
>
> If we're probing (silent==1) then don't complain about feature
> incompatibilities that are found if it looks like it's actually
> a different valid extN type - failed probes should be silent
> in this case.
>
> If the on-disk features are unknown even to ext4, then complain.
>
> Reported-by: Joakim Tjernlund <Joakim.Tjernlund@xxxxxxxxxxxx>
> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
> ---
>
> compile-tested only, sorry.
>
> V2. I lied. (actually I hand-edited the patch in mail) /Now/ it's compile tested,
> with the proper args to ext4_feature_set_ok :/
>
> Having 2 gotos like this might not be preferable, but trying
> to write it more compactly led to what I thought was more
> difficult-to-read logic.
Did a quick & dirty backport to 4.14.12 and tested and it works.
(yes, I noticed the error too :)
Thanks
Would be nice if sent to stable as well.
Tested-by: Joakim Tjernlund <Joakim.Tjernlund@xxxxxxxxxxxx>
>
>
>
>
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index b0915b7..ae40368 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -3659,6 +3659,12 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
> ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
> "using the ext4 subsystem");
> else {
> + /*
> + * If we're probing be silent, if this looks like
> + * it's actually an ext[34] filesystem.
> + */
> + if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
> + goto failed_mount;
> ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
> "to feature incompatibilities");
> goto failed_mount;
> @@ -3670,6 +3676,12 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
> ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
> "using the ext4 subsystem");
> else {
> + /*
> + * If we're probing be silent, if this looks like
> + * it's actually an ext4 filesystem.
> + */
> + if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
> + goto failed_mount;
> ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
> "to feature incompatibilities");
> goto failed_mount;
>
>
