xfs: clean up xfs_alloc_ag_vextent_exact

Use a goto label to consolidate all block not found cases, and add a
tracepoint for them.  Also clean up a few whitespace issues.

Based on an earlier patch from Dave Chinner.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>

diff --git a/fs/xfs/linux-2.6/xfs_trace.h b/fs/xfs/linux-2.6/xfs_trace.h
index f56431c..83e8760 100644 (file)
--- a/fs/xfs/linux-2.6/xfs_trace.h
+++ b/fs/xfs/linux-2.6/xfs_trace.h
@@ -1422,6 +1422,7 @@ DEFINE_EVENT(xfs_alloc_class, name, \
        TP_PROTO(struct xfs_alloc_arg *args), \
        TP_ARGS(args))
 DEFINE_ALLOC_EVENT(xfs_alloc_exact_done);
+DEFINE_ALLOC_EVENT(xfs_alloc_exact_notfound);
 DEFINE_ALLOC_EVENT(xfs_alloc_exact_error);
 DEFINE_ALLOC_EVENT(xfs_alloc_near_nominleft);
 DEFINE_ALLOC_EVENT(xfs_alloc_near_first);

diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index 112abc4..d9133f1 100644 (file)
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -577,61 +577,58 @@ xfs_alloc_ag_vextent_exact(
        xfs_extlen_t    rlen;   /* length of returned extent */
 
        ASSERT(args->alignment == 1);
+
        /*
         * Allocate/initialize a cursor for the by-number freespace btree.
         */
        bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
-               args->agno, XFS_BTNUM_BNO);
+                                         args->agno, XFS_BTNUM_BNO);
+
        /*
         * Lookup bno and minlen in the btree (minlen is irrelevant, really).
         * Look for the closest free block <= bno, it must contain bno
         * if any free block does.
         */
-       if ((error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i)))
+       error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i);
+       if (error)
                goto error0;
-       if (!i) {
-               /*
-                * Didn't find it, return null.
-                */
-               xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
-               args->agbno = NULLAGBLOCK;
-               return 0;
-       }
+       if (!i)
+               goto not_found;
+
        /*
         * Grab the freespace record.
         */
-       if ((error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i)))
+       error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i);
+       if (error)
                goto error0;
        XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
        ASSERT(fbno <= args->agbno);
        minend = args->agbno + args->minlen;
        maxend = args->agbno + args->maxlen;
        fend = fbno + flen;
+
        /*
         * Give up if the freespace isn't long enough for the minimum request.
         */
-       if (fend < minend) {
-               xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
-               args->agbno = NULLAGBLOCK;
-               return 0;
-       }
+       if (fend < minend)
+               goto not_found;
+
        /*
         * End of extent will be smaller of the freespace end and the
         * maximal requested end.
-        */
-       end = XFS_AGBLOCK_MIN(fend, maxend);
-       /*
+        *
         * Fix the length according to mod and prod if given.
         */
+       end = XFS_AGBLOCK_MIN(fend, maxend);
        args->len = end - args->agbno;
        xfs_alloc_fix_len(args);
-       if (!xfs_alloc_fix_minleft(args)) {
-               xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
-               return 0;
-       }
+       if (!xfs_alloc_fix_minleft(args))
+               goto not_found;
+
        rlen = args->len;
        ASSERT(args->agbno + rlen <= fend);
        end = args->agbno + rlen;
+
        /*
         * We are allocating agbno for rlen [agbno .. end]
         * Allocate/initialize a cursor for the by-size btree.
@@ -640,16 +637,25 @@ xfs_alloc_ag_vextent_exact(
                args->agno, XFS_BTNUM_CNT);
        ASSERT(args->agbno + args->len <=
                be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
-       if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen,
-                       args->agbno, args->len, XFSA_FIXUP_BNO_OK))) {
+       error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen, args->agbno,
+                                     args->len, XFSA_FIXUP_BNO_OK);
+       if (error) {
                xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
                goto error0;
        }
+
        xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
        xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
 
-       trace_xfs_alloc_exact_done(args);
        args->wasfromfl = 0;
+       trace_xfs_alloc_exact_done(args);
+       return 0;
+
+not_found:
+       /* Didn't find it, return null. */
+       xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
+       args->agbno = NULLAGBLOCK;
+       trace_xfs_alloc_exact_notfound(args);
        return 0;
 
 error0: