xfs: factor xfs_alloc_vextent_this_ag() for _iterate_ags()

The core of the per-ag iteration is effectively doing a "this ag"
allocation on one AG at a time. Use the same code to implement the
core "this ag" allocation in both xfs_alloc_vextent_this_ag()
and xfs_alloc_vextent_iterate_ags().

This means we only call xfs_alloc_ag_vextent() from one place so we
can easily collapse the call stack in future patches.

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 5afda10..98defd1 100644 (file)
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -3245,6 +3245,28 @@ xfs_alloc_vextent_set_fsbno(
  * Allocate within a single AG only.
  */
 static int
+__xfs_alloc_vextent_this_ag(
+       struct xfs_alloc_arg    *args)
+{
+       struct xfs_mount        *mp = args->mp;
+       int                     error;
+
+       error = xfs_alloc_fix_freelist(args, 0);
+       if (error) {
+               trace_xfs_alloc_vextent_nofix(args);
+               return error;
+       }
+       if (!args->agbp) {
+               /* cannot allocate in this AG at all */
+               trace_xfs_alloc_vextent_noagbp(args);
+               args->agbno = NULLAGBLOCK;
+               return 0;
+       }
+       args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
+       return xfs_alloc_ag_vextent(args);
+}
+
+static int
 xfs_alloc_vextent_this_ag(
        struct xfs_alloc_arg    *args,
        xfs_agnumber_t          minimum_agno)
@@ -3267,21 +3289,9 @@ xfs_alloc_vextent_this_ag(
        }
 
        args->pag = xfs_perag_get(mp, args->agno);
-       error = xfs_alloc_fix_freelist(args, 0);
-       if (error) {
-               trace_xfs_alloc_vextent_nofix(args);
-               goto out_error;
-       }
-       if (!args->agbp) {
-               trace_xfs_alloc_vextent_noagbp(args);
-               args->fsbno = NULLFSBLOCK;
-               goto out_error;
-       }
-       args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
-       error = xfs_alloc_ag_vextent(args);
+       error = __xfs_alloc_vextent_this_ag(args);
 
        xfs_alloc_vextent_set_fsbno(args, minimum_agno);
-out_error:
        xfs_perag_put(args->pag);
        return error;
 }
@@ -3319,24 +3329,16 @@ xfs_alloc_vextent_iterate_ags(
        args->agno = start_agno;
        for (;;) {
                args->pag = xfs_perag_get(mp, args->agno);
-               error = xfs_alloc_fix_freelist(args, flags);
+               error = __xfs_alloc_vextent_this_ag(args);
                if (error) {
-                       trace_xfs_alloc_vextent_nofix(args);
+                       args->agbno = NULLAGBLOCK;
                        break;
                }
-               /*
-                * If we get a buffer back then the allocation will fly.
-                */
-               if (args->agbp) {
-                       error = xfs_alloc_ag_vextent(args);
+               if (args->agbp)
                        break;
-               }
 
                trace_xfs_alloc_vextent_loopfailed(args);
 
-               /*
-                * Didn't work, figure out the next iteration.
-                */
                if (args->agno == start_agno &&
                    args->otype == XFS_ALLOCTYPE_START_BNO)
                        args->type = XFS_ALLOCTYPE_THIS_AG;