xfs: move allocation accounting to xfs_alloc_vextent_set_fsbno()

Move it from xfs_alloc_ag_vextent() so we can get rid of that layer.
Rename xfs_alloc_vextent_set_fsbno() to xfs_alloc_vextent_finish()
to indicate that it's function is finishing off the allocation that
we've run now that it contains much more functionality.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index dc1b6c6..afc6bd4 100644 (file)
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -1163,36 +1163,6 @@ xfs_alloc_ag_vextent(
                ASSERT(0);
                /* NOTREACHED */
        }
-
-       if (error || args->agbno == NULLAGBLOCK)
-               return error;
-
-       ASSERT(args->len >= args->minlen);
-       ASSERT(args->len <= args->maxlen);
-       ASSERT(args->agbno % args->alignment == 0);
-
-       /* if not file data, insert new block into the reverse map btree */
-       if (!xfs_rmap_should_skip_owner_update(&args->oinfo)) {
-               error = xfs_rmap_alloc(args->tp, args->agbp, args->pag,
-                                      args->agbno, args->len, &args->oinfo);
-               if (error)
-                       return error;
-       }
-
-       if (!args->wasfromfl) {
-               error = xfs_alloc_update_counters(args->tp, args->agbp,
-                                                 -((long)(args->len)));
-               if (error)
-                       return error;
-
-               ASSERT(!xfs_extent_busy_search(args->mp, args->pag,
-                                             args->agbno, args->len));
-       }
-
-       xfs_ag_resv_alloc_extent(args->pag, args->resv, args);
-
-       XFS_STATS_INC(args->mp, xs_allocx);
-       XFS_STATS_ADD(args->mp, xs_allocb, args->len);
        return error;
 }
 
@@ -3237,18 +3207,21 @@ xfs_alloc_vextent_prepare_ag(
 }
 
 /*
- * Post-process allocation results to set the allocated block number correctly
- * for the caller.
+ * Post-process allocation results to account for the allocation if it succeed
+ * and set the allocated block number correctly for the caller.
  *
- * XXX: xfs_alloc_vextent() should really be returning ENOSPC for ENOSPC, not
+ * XXX: we should really be returning ENOSPC for ENOSPC, not
  * hiding it behind a "successful" NULLFSBLOCK allocation.
  */
-static void
-xfs_alloc_vextent_set_fsbno(
+static int
+xfs_alloc_vextent_finish(
        struct xfs_alloc_arg    *args,
-       xfs_agnumber_t          minimum_agno)
+       xfs_agnumber_t          minimum_agno,
+       int                     alloc_error,
+       bool                    drop_perag)
 {
        struct xfs_mount        *mp = args->mp;
+       int                     error = 0;
 
        /*
         * We can end up here with a locked AGF. If we failed, the caller is
@@ -3271,19 +3244,54 @@ xfs_alloc_vextent_set_fsbno(
             args->agno > minimum_agno))
                args->tp->t_highest_agno = args->agno;
 
-       /* Allocation failed with ENOSPC if NULLAGBLOCK was returned. */
-       if (args->agbno == NULLAGBLOCK) {
+       /*
+        * If the allocation failed with an error or we had an ENOSPC result,
+        * preserve the returned error whilst also marking the allocation result
+        * as "no extent allocated". This ensures that callers that fail to
+        * capture the error will still treat it as a failed allocation.
+        */
+       if (alloc_error || args->agbno == NULLAGBLOCK) {
                args->fsbno = NULLFSBLOCK;
-               return;
+               error = alloc_error;
+               goto out_drop_perag;
        }
 
        args->fsbno = XFS_AGB_TO_FSB(mp, args->agno, args->agbno);
-#ifdef DEBUG
+
        ASSERT(args->len >= args->minlen);
        ASSERT(args->len <= args->maxlen);
        ASSERT(args->agbno % args->alignment == 0);
        XFS_AG_CHECK_DADDR(mp, XFS_FSB_TO_DADDR(mp, args->fsbno), args->len);
-#endif
+
+       /* if not file data, insert new block into the reverse map btree */
+       if (!xfs_rmap_should_skip_owner_update(&args->oinfo)) {
+               error = xfs_rmap_alloc(args->tp, args->agbp, args->pag,
+                                      args->agbno, args->len, &args->oinfo);
+               if (error)
+                       goto out_drop_perag;
+       }
+
+       if (!args->wasfromfl) {
+               error = xfs_alloc_update_counters(args->tp, args->agbp,
+                                                 -((long)(args->len)));
+               if (error)
+                       goto out_drop_perag;
+
+               ASSERT(!xfs_extent_busy_search(mp, args->pag, args->agbno,
+                               args->len));
+       }
+
+       xfs_ag_resv_alloc_extent(args->pag, args->resv, args);
+
+       XFS_STATS_INC(mp, xs_allocx);
+       XFS_STATS_ADD(mp, xs_allocb, args->len);
+
+out_drop_perag:
+       if (drop_perag) {
+               xfs_perag_put(args->pag);
+               args->pag = NULL;
+       }
+       return error;
 }
 
 /*
@@ -3325,8 +3333,7 @@ xfs_alloc_vextent_this_ag(
        if (!error && args->agbp)
                error = xfs_alloc_ag_vextent(args);
 
-       xfs_alloc_vextent_set_fsbno(args, minimum_agno);
-       return error;
+       return xfs_alloc_vextent_finish(args, minimum_agno, error, false);
 }
 
 /*
@@ -3413,10 +3420,10 @@ xfs_alloc_vextent_iterate_ags(
                xfs_perag_put(args->pag);
                args->pag = NULL;
        }
-       if (args->pag) {
-               xfs_perag_put(args->pag);
-               args->pag = NULL;
-       }
+       /*
+        * The perag is left referenced in args for the caller to clean
+        * up after they've finished the allocation.
+        */
        return error;
 }
 
@@ -3473,8 +3480,7 @@ xfs_alloc_vextent_start_ag(
                                (mp->m_sb.sb_agcount * rotorstep);
        }
 
-       xfs_alloc_vextent_set_fsbno(args, minimum_agno);
-       return error;
+       return xfs_alloc_vextent_finish(args, minimum_agno, error, true);
 }
 
 /*
@@ -3507,8 +3513,7 @@ xfs_alloc_vextent_first_ag(
        args->fsbno = target;
        error = xfs_alloc_vextent_iterate_ags(args, minimum_agno,
                        start_agno, 0);
-       xfs_alloc_vextent_set_fsbno(args, minimum_agno);
-       return error;
+       return xfs_alloc_vextent_finish(args, minimum_agno, error, true);
 }
 
 /*
@@ -3537,6 +3542,7 @@ xfs_alloc_vextent_exact_bno(
        args->agno = XFS_FSB_TO_AGNO(mp, target);
        if (minimum_agno > args->agno) {
                trace_xfs_alloc_vextent_skip_deadlock(args);
+               args->fsbno = NULLFSBLOCK;
                return 0;
        }
 
@@ -3548,8 +3554,7 @@ xfs_alloc_vextent_exact_bno(
        if (!error && args->agbp)
                error = xfs_alloc_ag_vextent(args);
 
-       xfs_alloc_vextent_set_fsbno(args, minimum_agno);
-       return 0;
+       return xfs_alloc_vextent_finish(args, minimum_agno, error, false);
 }
 
 /*
@@ -3564,8 +3569,8 @@ xfs_alloc_vextent_near_bno(
        xfs_fsblock_t           target)
 {
        struct xfs_mount        *mp = args->mp;
-       bool                    need_pag = !args->pag;
        xfs_agnumber_t          minimum_agno = 0;
+       bool                    needs_perag = args->pag == NULL;
        int                     error;
 
        if (args->tp->t_highest_agno != NULLAGNUMBER)
@@ -3585,6 +3590,9 @@ xfs_alloc_vextent_near_bno(
                return 0;
        }
 
+       if (needs_perag)
+               args->pag = xfs_perag_get(mp, args->agno);
+
        args->agbno = XFS_FSB_TO_AGBNO(mp, target);
        args->type = XFS_ALLOCTYPE_NEAR_BNO;
 
@@ -3592,11 +3600,7 @@ xfs_alloc_vextent_near_bno(
        if (!error && args->agbp)
                error = xfs_alloc_ag_vextent(args);
 
-       xfs_alloc_vextent_set_fsbno(args, minimum_agno);
-       if (need_pag)
-               xfs_perag_put(args->pag);
-
-       return error;
+       return xfs_alloc_vextent_finish(args, minimum_agno, error, needs_perag);
 }
 
 /* Ensure that the freelist is at full capacity. */