On Mon 02-05-16 12:42:56, Toshi Kani wrote: > When a partition is not aligned by 4KB, mount -o dax succeeds, > but any read/write access to the filesystem fails, except for > metadata update. > > Call bdev_direct_access to check the alignment when -o dax is > specified. > > Reported-by: Micah Parrish <[email protected]> > Signed-off-by: Toshi Kani <[email protected]> > Cc: "Theodore Ts'o" <[email protected]> > Cc: Andreas Dilger <[email protected]> > Cc: Jan Kara <[email protected]> > Cc: Dan Williams <[email protected]> > Cc: Ross Zwisler <[email protected]> > Cc: Christoph Hellwig <[email protected]> > Cc: Boaz Harrosh <[email protected]>
Looks good to me. You can add: Reviewed-by: Jan Kara <[email protected]> Honza > --- > fs/ext4/super.c | 20 ++++++++++++++++++-- > 1 file changed, 18 insertions(+), 2 deletions(-) > > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index 304c712..51ac78e 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -3416,14 +3416,30 @@ static int ext4_fill_super(struct super_block *sb, > void *data, int silent) > } > > if (sbi->s_mount_opt & EXT4_MOUNT_DAX) { > + struct blk_dax_ctl dax = { > + .sector = 0, > + .size = PAGE_SIZE, > + }; > if (blocksize != PAGE_SIZE) { > ext4_msg(sb, KERN_ERR, > "error: unsupported blocksize for dax"); > goto failed_mount; > } > - if (!sb->s_bdev->bd_disk->fops->direct_access) { > - ext4_msg(sb, KERN_ERR, > + err = bdev_direct_access(sb->s_bdev, &dax); > + if (err < 0) { > + switch (err) { > + case -EOPNOTSUPP: > + ext4_msg(sb, KERN_ERR, > "error: device does not support dax"); > + break; > + case -EINVAL: > + ext4_msg(sb, KERN_ERR, > + "error: unaligned partition for dax"); > + break; > + default: > + ext4_msg(sb, KERN_ERR, > + "error: dax access failed (%d)", err); > + } > goto failed_mount; > } > } -- Jan Kara <[email protected]> SUSE Labs, CR
