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

John Garry
2025-02-25T11:13:54Z

>> @@ -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