xfs: implement the GETFSMAP ioctl

Introduce a new ioctl that uses the reverse mapping btree to return
information about the physical layout of the filesystem.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
This commit is contained in:
Darrick J. Wong
2017-03-28 14:56:37 -07:00
parent fb3c3de2f6
commit e89c041338
12 changed files with 1048 additions and 0 deletions

View File

@@ -2305,3 +2305,31 @@ xfs_rmap_free_extent(
return __xfs_rmap_add(mp, dfops, XFS_RMAP_FREE, owner,
XFS_DATA_FORK, &bmap);
}
/* Compare rmap records. Returns -1 if a < b, 1 if a > b, and 0 if equal. */
int
xfs_rmap_compare(
const struct xfs_rmap_irec *a,
const struct xfs_rmap_irec *b)
{
__u64 oa;
__u64 ob;
oa = xfs_rmap_irec_offset_pack(a);
ob = xfs_rmap_irec_offset_pack(b);
if (a->rm_startblock < b->rm_startblock)
return -1;
else if (a->rm_startblock > b->rm_startblock)
return 1;
else if (a->rm_owner < b->rm_owner)
return -1;
else if (a->rm_owner > b->rm_owner)
return 1;
else if (oa < ob)
return -1;
else if (oa > ob)
return 1;
else
return 0;
}