4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Sandeen <sandeen@xxxxxxxxxx> [ Upstream commit 0d9366d67bcf066b028e57d09c9a86ce879bcc28 ] 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> Tested-by: Joakim Tjernlund <Joakim.Tjernlund@xxxxxxxxxxxx> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx> Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Reviewed-by: Jan Kara <jack@xxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/ext4/super.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3663,6 +3663,12 @@ static int ext4_fill_super(struct super_ 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; @@ -3674,6 +3680,12 @@ static int ext4_fill_super(struct super_ 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;