On Sat 23-12-17 16:56:11, Dan Williams wrote:
> Bring the ext4 filesystem in line with xfs that only warns and continues
> when the "-o dax" option is specified to mount and the backing device
> does not support dax. This is in preparation for removing dax support
> from devices that do not enable get_user_pages() operations on dax
> mappings. In other words 'gup' support is required and configurations
> that were using so called 'page-less' dax will be converted back to
> using the page cache.
>
> Removing the broken 'page-less' dax support is a pre-requisite for
> removing the "EXPERIMENTAL" warning when mounting a filesystem in dax
> mode.
>
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
OK, given the fact that we already silently disable DAX for inodes with
data journalling I agree this makes sense. You can add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/ext4/super.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 7c46693a14d7..18873ea89e08 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -3710,11 +3710,14 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
> if (ext4_has_feature_inline_data(sb)) {
> ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
> " that may contain inline data");
> - goto failed_mount;
> + sbi->s_mount_opt &= ~EXT4_MOUNT_DAX;
> }
> err = bdev_dax_supported(sb, blocksize);
> - if (err)
> - goto failed_mount;
> + if (err) {
> + ext4_msg(sb, KERN_ERR,
> + "DAX unsupported by block device. Turning off DAX.");
> + sbi->s_mount_opt &= ~EXT4_MOUNT_DAX;
> + }
> }
>
> if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
