1 files changed, 28 insertions, 87 deletions

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 5050056a0b06..9f06a211e157 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -95,10 +95,7 @@ unsigned int
 xfs_alloc_set_aside(
         struct xfs_mount        *mp)
 {
-        unsigned int            blocks;
-
-        blocks = 4 + (mp->m_sb.sb_agcount * XFS_ALLOC_AGFL_RESERVE);
-        return blocks;
+        return mp->m_sb.sb_agcount * (XFS_ALLOC_AGFL_RESERVE + 4);
 }
 
 /*
@@ -365,36 +362,12 @@ xfs_alloc_fix_len(
                 return;
         ASSERT(rlen >= args->minlen && rlen <= args->maxlen);
         ASSERT(rlen % args->prod == args->mod);
+        ASSERT(args->pag->pagf_freeblks + args->pag->pagf_flcount >=
+                rlen + args->minleft);
         args->len = rlen;
 }
 
 /*
- * Fix up length if there is too little space left in the a.g.
- * Return 1 if ok, 0 if too little, should give up.
- */
-STATIC int
-xfs_alloc_fix_minleft(
-        xfs_alloc_arg_t *args)          /* allocation argument structure */
-{
-        xfs_agf_t       *agf;           /* a.g. freelist header */
-        int             diff;           /* free space difference */
-
-        if (args->minleft == 0)
-                return 1;
-        agf = XFS_BUF_TO_AGF(args->agbp);
-        diff = be32_to_cpu(agf->agf_freeblks)
-                - args->len - args->minleft;
-        if (diff >= 0)
-                return 1;
-        args->len += diff;              /* shrink the allocated space */
-        /* casts to (int) catch length underflows */
-        if ((int)args->len >= (int)args->minlen)
-                return 1;
-        args->agbno = NULLAGBLOCK;
-        return 0;
-}
-
-/*
  * Update the two btrees, logically removing from freespace the extent
  * starting at rbno, rlen blocks.  The extent is contained within the
  * actual (current) free extent fbno for flen blocks.
@@ -689,8 +662,6 @@ xfs_alloc_ag_vextent(
         xfs_alloc_arg_t *args)  /* argument structure for allocation */
 {
         int             error=0;
-        xfs_extlen_t    reservation;
-        xfs_extlen_t    oldmax;
 
         ASSERT(args->minlen > 0);
         ASSERT(args->maxlen > 0);
@@ -699,20 +670,6 @@ xfs_alloc_ag_vextent(
         ASSERT(args->alignment > 0);
 
         /*
-         * Clamp maxlen to the amount of free space minus any reservations
-         * that have been made.
-         */
-        oldmax = args->maxlen;
-        reservation = xfs_ag_resv_needed(args->pag, args->resv);
-        if (args->maxlen > args->pag->pagf_freeblks - reservation)
-                args->maxlen = args->pag->pagf_freeblks - reservation;
-        if (args->maxlen == 0) {
-                args->agbno = NULLAGBLOCK;
-                args->maxlen = oldmax;
-                return 0;
-        }
-
-        /*
          * Branch to correct routine based on the type.
          */
         args->wasfromfl = 0;
@@ -731,8 +688,6 @@ xfs_alloc_ag_vextent(
                 /* NOTREACHED */
         }
 
-        args->maxlen = oldmax;
-
         if (error || args->agbno == NULLAGBLOCK)
                 return error;
 
@@ -841,9 +796,6 @@ xfs_alloc_ag_vextent_exact(
         args->len = XFS_AGBLOCK_MIN(tend, args->agbno + args->maxlen)
                                                 - args->agbno;
         xfs_alloc_fix_len(args);
-        if (!xfs_alloc_fix_minleft(args))
-                goto not_found;
-
         ASSERT(args->agbno + args->len <= tend);
 
         /*
@@ -1149,12 +1101,7 @@ restart:
                 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
                 ASSERT(ltbno + ltlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
                 args->len = blen;
-                if (!xfs_alloc_fix_minleft(args)) {
-                        xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
-                        trace_xfs_alloc_near_nominleft(args);
-                        return 0;
-                }
-                blen = args->len;
+
                 /*
                  * We are allocating starting at bnew for blen blocks.
                  */
@@ -1346,12 +1293,6 @@ restart:
          */
         args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
         xfs_alloc_fix_len(args);
-        if (!xfs_alloc_fix_minleft(args)) {
-                trace_xfs_alloc_near_nominleft(args);
-                xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
-                xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
-                return 0;
-        }
         rlen = args->len;
         (void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment,
                                      args->datatype, ltbnoa, ltlena, &ltnew);
@@ -1553,8 +1494,6 @@ restart:
         }
         xfs_alloc_fix_len(args);
 
-        if (!xfs_alloc_fix_minleft(args))
-                goto out_nominleft;
         rlen = args->len;
         XFS_WANT_CORRUPTED_GOTO(args->mp, rlen <= flen, error0);
         /*
@@ -2056,7 +1995,7 @@ xfs_alloc_space_available(
         int                     flags)
 {
         struct xfs_perag        *pag = args->pag;
-        xfs_extlen_t            longest;
+        xfs_extlen_t            alloc_len, longest;
         xfs_extlen_t            reservation; /* blocks that are still reserved */
         int                     available;
 
@@ -2066,17 +2005,28 @@ xfs_alloc_space_available(
         reservation = xfs_ag_resv_needed(pag, args->resv);
 
         /* do we have enough contiguous free space for the allocation? */
+        alloc_len = args->minlen + (args->alignment - 1) + args->minalignslop;
         longest = xfs_alloc_longest_free_extent(args->mp, pag, min_free,
                         reservation);
-        if ((args->minlen + args->alignment + args->minalignslop - 1) > longest)
+        if (longest < alloc_len)
                 return false;
 
         /* do we have enough free space remaining for the allocation? */
         available = (int)(pag->pagf_freeblks + pag->pagf_flcount -
-                          reservation - min_free - args->total);
-        if (available < (int)args->minleft || available <= 0)
+                          reservation - min_free - args->minleft);
+        if (available < (int)max(args->total, alloc_len))
                 return false;
 
+        /*
+         * Clamp maxlen to the amount of free space available for the actual
+         * extent allocation.
+         */
+        if (available < (int)args->maxlen && !(flags & XFS_ALLOC_FLAG_CHECK)) {
+                args->maxlen = available;
+                ASSERT(args->maxlen > 0);
+                ASSERT(args->maxlen >= args->minlen);
+        }
+
         return true;
 }
 
@@ -2122,7 +2072,8 @@ xfs_alloc_fix_freelist(
         }
 
         need = xfs_alloc_min_freelist(mp, pag);
-        if (!xfs_alloc_space_available(args, need, flags))
+        if (!xfs_alloc_space_available(args, need, flags |
+                        XFS_ALLOC_FLAG_CHECK))
                 goto out_agbp_relse;
 
         /*
@@ -2638,12 +2589,10 @@ xfs_alloc_vextent(
         xfs_agblock_t   agsize; /* allocation group size */
         int             error;
         int             flags;  /* XFS_ALLOC_FLAG_... locking flags */
-        xfs_extlen_t    minleft;/* minimum left value, temp copy */
         xfs_mount_t     *mp;    /* mount structure pointer */
         xfs_agnumber_t  sagno;  /* starting allocation group number */
         xfs_alloctype_t type;   /* input allocation type */
         int             bump_rotor = 0;
-        int             no_min = 0;
         xfs_agnumber_t  rotorstep = xfs_rotorstep; /* inode32 agf stepper */
 
         mp = args->mp;
@@ -2672,7 +2621,6 @@ xfs_alloc_vextent(
                 trace_xfs_alloc_vextent_badargs(args);
                 return 0;
         }
-        minleft = args->minleft;
 
         switch (type) {
         case XFS_ALLOCTYPE_THIS_AG:
@@ -2683,9 +2631,7 @@ xfs_alloc_vextent(
                  */
                 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
                 args->pag = xfs_perag_get(mp, args->agno);
-                args->minleft = 0;
                 error = xfs_alloc_fix_freelist(args, 0);
-                args->minleft = minleft;
                 if (error) {
                         trace_xfs_alloc_vextent_nofix(args);
                         goto error0;
@@ -2750,9 +2696,7 @@ xfs_alloc_vextent(
                  */
                 for (;;) {
                         args->pag = xfs_perag_get(mp, args->agno);
-                        if (no_min) args->minleft = 0;
                         error = xfs_alloc_fix_freelist(args, flags);
-                        args->minleft = minleft;
                         if (error) {
                                 trace_xfs_alloc_vextent_nofix(args);
                                 goto error0;
@@ -2792,20 +2736,17 @@ xfs_alloc_vextent(
                          * or switch to non-trylock mode.
                          */
                         if (args->agno == sagno) {
-                                if (no_min == 1) {
+                                if (flags == 0) {
                                         args->agbno = NULLAGBLOCK;
                                         trace_xfs_alloc_vextent_allfailed(args);
                                         break;
                                 }
-                                if (flags == 0) {
-                                        no_min = 1;
-                                } else {
-                                        flags = 0;
-                                        if (type == XFS_ALLOCTYPE_START_BNO) {
-                                                args->agbno = XFS_FSB_TO_AGBNO(mp,
-                                                        args->fsbno);
-                                                args->type = XFS_ALLOCTYPE_NEAR_BNO;
-                                        }
+
+                                flags = 0;
+                                if (type == XFS_ALLOCTYPE_START_BNO) {
+                                        args->agbno = XFS_FSB_TO_AGBNO(mp,
+                                                args->fsbno);
+                                        args->type = XFS_ALLOCTYPE_NEAR_BNO;
                                 }
                         }
                         xfs_perag_put(args->pag);