diff mbox

xfs: fix rt_dev usage for DAX

Message ID 151744400024.39505.6657033185117899561.stgit@djiang5-desk3.ch.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dave Jiang Feb. 1, 2018, 12:13 a.m. UTC
When using realtime device (rtdev) with xfs where the data device is not
DAX capable, two issues arise. One is when data device is not DAX but the
realtime device is DAX capable, we currently disable DAX.
After passing this check, we are also not marking the inode as DAX capable.
This change will allow DAX enabled if the data device or the realtime
device is DAX capable. S_DAX will be marked for the inode if the file is
residing on a DAX capable device. This will prevent the case of rtdev is not
DAX and data device is DAX to create realtime files.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reported-by: Darrick Wong <darrick.wong@oracle.com>
---
 fs/xfs/xfs_iops.c  |    3 ++-
 fs/xfs/xfs_super.c |    2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

Comments

Darrick J. Wong Feb. 1, 2018, 12:29 a.m. UTC | #1
On Wed, Jan 31, 2018 at 05:13:20PM -0700, Dave Jiang wrote:
> When using realtime device (rtdev) with xfs where the data device is not
> DAX capable, two issues arise. One is when data device is not DAX but the
> realtime device is DAX capable, we currently disable DAX.
> After passing this check, we are also not marking the inode as DAX capable.
> This change will allow DAX enabled if the data device or the realtime
> device is DAX capable. S_DAX will be marked for the inode if the file is
> residing on a DAX capable device. This will prevent the case of rtdev is not
> DAX and data device is DAX to create realtime files.
> 
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> Reported-by: Darrick Wong <darrick.wong@oracle.com>
> ---
>  fs/xfs/xfs_iops.c  |    3 ++-
>  fs/xfs/xfs_super.c |    2 +-
>  2 files changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
> index 56475fcd76f2..ab352c325301 100644
> --- a/fs/xfs/xfs_iops.c
> +++ b/fs/xfs/xfs_iops.c
> @@ -1204,7 +1204,8 @@ xfs_diflags_to_iflags(
>  	    ip->i_mount->m_sb.sb_blocksize == PAGE_SIZE &&
>  	    !xfs_is_reflink_inode(ip) &&
>  	    (ip->i_mount->m_flags & XFS_MOUNT_DAX ||
> -	     ip->i_d.di_flags2 & XFS_DIFLAG2_DAX))
> +	     ip->i_d.di_flags2 & XFS_DIFLAG2_DAX) &&
> +	    blk_queue_dax(bdev_get_queue(inode->i_sb->s_bdev)))
>  		inode->i_flags |= S_DAX;
>  }
>  
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index 1dacccc367f8..2b2a02bcf72e 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -1653,7 +1653,7 @@ xfs_fs_fill_super(
>  		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
>  
>  		error = bdev_dax_supported(sb, sb->s_blocksize);
> -		if (error) {
> +		if (error && !mp->m_rtdev_targp->bt_daxdev) {

Don't we have to do all the other __bdev_dax_supported checks on the
rtdev too?  It seems to want to check that dax_direct_access actually
works before it commits to returning 0, and I don't see why you wouldn't
do that for the dax rtdev too.

--D

>  			xfs_alert(mp,
>  			"DAX unsupported by block device. Turning off DAX.");
>  			mp->m_flags &= ~XFS_MOUNT_DAX;
> 
> --
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Dave Jiang Feb. 1, 2018, 12:40 a.m. UTC | #2
On 01/31/2018 05:29 PM, Darrick J. Wong wrote:
> On Wed, Jan 31, 2018 at 05:13:20PM -0700, Dave Jiang wrote:
>> When using realtime device (rtdev) with xfs where the data device is not
>> DAX capable, two issues arise. One is when data device is not DAX but the
>> realtime device is DAX capable, we currently disable DAX.
>> After passing this check, we are also not marking the inode as DAX capable.
>> This change will allow DAX enabled if the data device or the realtime
>> device is DAX capable. S_DAX will be marked for the inode if the file is
>> residing on a DAX capable device. This will prevent the case of rtdev is not
>> DAX and data device is DAX to create realtime files.
>>
>> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
>> Reported-by: Darrick Wong <darrick.wong@oracle.com>
>> ---
>>   fs/xfs/xfs_iops.c  |    3 ++-
>>   fs/xfs/xfs_super.c |    2 +-
>>   2 files changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
>> index 56475fcd76f2..ab352c325301 100644
>> --- a/fs/xfs/xfs_iops.c
>> +++ b/fs/xfs/xfs_iops.c
>> @@ -1204,7 +1204,8 @@ xfs_diflags_to_iflags(
>>   	    ip->i_mount->m_sb.sb_blocksize == PAGE_SIZE &&
>>   	    !xfs_is_reflink_inode(ip) &&
>>   	    (ip->i_mount->m_flags & XFS_MOUNT_DAX ||
>> -	     ip->i_d.di_flags2 & XFS_DIFLAG2_DAX))
>> +	     ip->i_d.di_flags2 & XFS_DIFLAG2_DAX) &&
>> +	    blk_queue_dax(bdev_get_queue(inode->i_sb->s_bdev)))
>>   		inode->i_flags |= S_DAX;
>>   }
>>   
>> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
>> index 1dacccc367f8..2b2a02bcf72e 100644
>> --- a/fs/xfs/xfs_super.c
>> +++ b/fs/xfs/xfs_super.c
>> @@ -1653,7 +1653,7 @@ xfs_fs_fill_super(
>>   		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
>>   
>>   		error = bdev_dax_supported(sb, sb->s_blocksize);
>> -		if (error) {
>> +		if (error && !mp->m_rtdev_targp->bt_daxdev) {
> 
> Don't we have to do all the other __bdev_dax_supported checks on the
> rtdev too?  It seems to want to check that dax_direct_access actually
> works before it commits to returning 0, and I don't see why you wouldn't
> do that for the dax rtdev too.

Ok. I was thinking that fs_dax_get_by_bdev() from xfs_open_devices() was 
sufficient. I think now your comment that __bdev_dax_supported() should 
take a block_device rather than a super_block makes sense.

> 
> --D
> 
>>   			xfs_alert(mp,
>>   			"DAX unsupported by block device. Turning off DAX.");
>>   			mp->m_flags &= ~XFS_MOUNT_DAX;
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 56475fcd76f2..ab352c325301 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1204,7 +1204,8 @@  xfs_diflags_to_iflags(
 	    ip->i_mount->m_sb.sb_blocksize == PAGE_SIZE &&
 	    !xfs_is_reflink_inode(ip) &&
 	    (ip->i_mount->m_flags & XFS_MOUNT_DAX ||
-	     ip->i_d.di_flags2 & XFS_DIFLAG2_DAX))
+	     ip->i_d.di_flags2 & XFS_DIFLAG2_DAX) &&
+	    blk_queue_dax(bdev_get_queue(inode->i_sb->s_bdev)))
 		inode->i_flags |= S_DAX;
 }
 
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 1dacccc367f8..2b2a02bcf72e 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1653,7 +1653,7 @@  xfs_fs_fill_super(
 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
 
 		error = bdev_dax_supported(sb, sb->s_blocksize);
-		if (error) {
+		if (error && !mp->m_rtdev_targp->bt_daxdev) {
 			xfs_alert(mp,
 			"DAX unsupported by block device. Turning off DAX.");
 			mp->m_flags &= ~XFS_MOUNT_DAX;