Re: [PATCH v2 10/11] xfs: Update atomic write max size

[John Garry <john.g.garry@oracle.com>]

>> @@ -22,5 +22,4 @@ extern void xfs_diflags_to_iflags(struct xfs_inode *ip, bool init);
>>   void xfs_get_atomic_write_attr(struct xfs_inode *ip,
>>   		unsigned int *unit_min, unsigned int *unit_max);
>>   
>> -
> 
> No need to remove a blank line.


ok
> 
>>   #endif /* __XFS_IOPS_H__ */
>> diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
>> index 477c5262cf91..af3ed135be4d 100644
>> --- a/fs/xfs/xfs_mount.c
>> +++ b/fs/xfs/xfs_mount.c
>> @@ -651,6 +651,32 @@ xfs_agbtree_compute_maxlevels(
>>   	levels = max(levels, mp->m_rmap_maxlevels);
>>   	mp->m_agbtree_maxlevels = max(levels, mp->m_refc_maxlevels);
>>   }
>> +static inline void
>> +xfs_compute_awu_max(
>> +	struct xfs_mount	*mp)
>> +{
>> +	xfs_agblock_t		agsize = mp->m_sb.sb_agblocks;
>> +	xfs_agblock_t		awu_max;
>> +
>> +	if (!xfs_has_reflink(mp)) {
>> +		mp->awu_max = 1;
>> +		return;
>> +	}
>> +
>> +	/*
>> +	 * Find highest power-of-2 evenly divisible into agsize and which
>> +	 * also fits into an unsigned int field.
>> +	 */
>> +	awu_max = 1;
>> +	while (1) {
>> +		if (agsize % (awu_max * 2))
>> +			break;
>> +		if (XFS_FSB_TO_B(mp, awu_max * 2) > UINT_MAX)
>> +			break;
>> +		awu_max *= 2;
>> +	}
>> +	mp->awu_max = awu_max;
>> +}
>>   
>>   /* Compute maximum possible height for realtime btree types for this fs. */
>>   static inline void
>> @@ -736,6 +762,8 @@ xfs_mountfs(
>>   	xfs_agbtree_compute_maxlevels(mp);
>>   	xfs_rtbtree_compute_maxlevels(mp);
>>   
>> +	xfs_compute_awu_max(mp);
>> +
>>   	/*
>>   	 * Check if sb_agblocks is aligned at stripe boundary.  If sb_agblocks
>>   	 * is NOT aligned turn off m_dalign since allocator alignment is within
>> diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
>> index fbed172d6770..34286c87ac4a 100644
>> --- a/fs/xfs/xfs_mount.h
>> +++ b/fs/xfs/xfs_mount.h
>> @@ -198,6 +198,7 @@ typedef struct xfs_mount {
>>   	bool			m_fail_unmount;
>>   	bool			m_finobt_nores; /* no per-AG finobt resv. */
>>   	bool			m_update_sb;	/* sb needs update in mount */
>> +	xfs_extlen_t		awu_max;	/* max atomic write */
> 
> Might want to clarify that this is for the *data* device.

sure

> 
> 	/* max atomic write to datadev */
> 
> With those two things fixed,
> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

cheers