xfs: tune down agno asserts in the bmap code

In various places we currently assert that xfs_bmap_btalloc allocates
from the same as the firstblock value passed in, unless it's either
NULLAGNO or the dop_low flag is set.  But the reflink code does not
fully follow this convention as it passes in firstblock purely as
a hint for the allocator without actually having previous allocations
in the transaction, and without having a minleft check on the current
AG, leading to the assert firing on a very full and heavily used
file system.  As even the reflink code only allocates from equal or
higher AGs for now we can simply the check to always allow for equal
or higher AGs.

Note that we need to eventually split the two meanings of the firstblock
value.  At that point we can also allow the reflink code to allocate
from any AG instead of limiting it in any way.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 2ae55db8c977dde4b175a6fe67bc6b637e2cddd7..a9c66d47757a757324e5fbf4224883e1d369588a 100644 (file)
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -798,9 +798,7 @@ try_another_ag:
         */
        ASSERT(args.fsbno != NULLFSBLOCK);
        ASSERT(*firstblock == NULLFSBLOCK ||
-              args.agno == XFS_FSB_TO_AGNO(mp, *firstblock) ||
-              (dfops->dop_low &&
-               args.agno > XFS_FSB_TO_AGNO(mp, *firstblock)));
+              args.agno >= XFS_FSB_TO_AGNO(mp, *firstblock));
        *firstblock = cur->bc_private.b.firstblock = args.fsbno;
        cur->bc_private.b.allocated++;
        ip->i_d.di_nblocks++;
@@ -3822,17 +3820,13 @@ xfs_bmap_btalloc(
                 * the first block that was allocated.
                 */
                ASSERT(*ap->firstblock == NULLFSBLOCK ||
-                      XFS_FSB_TO_AGNO(mp, *ap->firstblock) ==
-                      XFS_FSB_TO_AGNO(mp, args.fsbno) ||
-                      (ap->dfops->dop_low &&
-                       XFS_FSB_TO_AGNO(mp, *ap->firstblock) <
-                       XFS_FSB_TO_AGNO(mp, args.fsbno)));
+                      XFS_FSB_TO_AGNO(mp, *ap->firstblock) <=
+                      XFS_FSB_TO_AGNO(mp, args.fsbno));
 
                ap->blkno = args.fsbno;
                if (*ap->firstblock == NULLFSBLOCK)
                        *ap->firstblock = args.fsbno;
-               ASSERT(nullfb || fb_agno == args.agno ||
-                      (ap->dfops->dop_low && fb_agno < args.agno));
+               ASSERT(nullfb || fb_agno <= args.agno);
                ap->length = args.len;
                if (!(ap->flags & XFS_BMAPI_COWFORK))
                        ap->ip->i_d.di_nblocks += args.len;
@@ -4754,13 +4748,9 @@ error0:
        if (bma.cur) {
                if (!error) {
                        ASSERT(*firstblock == NULLFSBLOCK ||
-                              XFS_FSB_TO_AGNO(mp, *firstblock) ==
+                              XFS_FSB_TO_AGNO(mp, *firstblock) <=
                               XFS_FSB_TO_AGNO(mp,
-                                      bma.cur->bc_private.b.firstblock) ||
-                              (dfops->dop_low &&
-                               XFS_FSB_TO_AGNO(mp, *firstblock) <
-                               XFS_FSB_TO_AGNO(mp,
-                                       bma.cur->bc_private.b.firstblock)));
+                                      bma.cur->bc_private.b.firstblock));
                        *firstblock = bma.cur->bc_private.b.firstblock;
                }
                xfs_btree_del_cursor(bma.cur,