Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs

[pandora-kernel.git] / fs / xfs / xfs_alloc.c

diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index acdced8..1e00b3e 100644 (file)
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -570,9 +570,7 @@ xfs_alloc_ag_vextent_exact(
        xfs_agblock_t   tbno;   /* start block of trimmed extent */
        xfs_extlen_t    tlen;   /* length of trimmed extent */
        xfs_agblock_t   tend;   /* end block of trimmed extent */
-       xfs_agblock_t   end;    /* end of allocated extent */
        int             i;      /* success/failure of operation */
-       xfs_extlen_t    rlen;   /* length of returned extent */
 
        ASSERT(args->alignment == 1);
 
@@ -625,18 +623,16 @@ xfs_alloc_ag_vextent_exact(
         *
         * Fix the length according to mod and prod if given.
         */
-       end = XFS_AGBLOCK_MIN(tend, args->agbno + args->maxlen);
-       args->len = end - args->agbno;
+       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;
 
-       rlen = args->len;
-       ASSERT(args->agbno + rlen <= tend);
-       end = args->agbno + rlen;
+       ASSERT(args->agbno + args->len <= tend);
 
        /*
-        * We are allocating agbno for rlen [agbno .. end]
+        * We are allocating agbno for args->len
         * Allocate/initialize a cursor for the by-size btree.
         */
        cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
@@ -2127,7 +2123,7 @@ xfs_read_agf(
         * Validate the magic number of the agf block.
         */
        agf_ok =
-               be32_to_cpu(agf->agf_magicnum) == XFS_AGF_MAGIC &&
+               agf->agf_magicnum == cpu_to_be32(XFS_AGF_MAGIC) &&
                XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
                be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
                be32_to_cpu(agf->agf_flfirst) < XFS_AGFL_SIZE(mp) &&
@@ -2469,7 +2465,7 @@ xfs_free_extent(
 
        error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno, len, 0);
        if (!error)
-               xfs_alloc_busy_insert(tp, args.agno, args.agbno, len);
+               xfs_alloc_busy_insert(tp, args.agno, args.agbno, len, 0);
 error0:
        xfs_perag_put(args.pag);
        return error;
@@ -2480,7 +2476,8 @@ xfs_alloc_busy_insert(
        struct xfs_trans        *tp,
        xfs_agnumber_t          agno,
        xfs_agblock_t           bno,
-       xfs_extlen_t            len)
+       xfs_extlen_t            len,
+       unsigned int            flags)
 {
        struct xfs_busy_extent  *new;
        struct xfs_busy_extent  *busyp;
@@ -2504,6 +2501,7 @@ xfs_alloc_busy_insert(
        new->bno = bno;
        new->length = len;
        INIT_LIST_HEAD(&new->list);
+       new->flags = flags;
 
        /* trace before insert to be able to see failed inserts */
        trace_xfs_alloc_busy(tp->t_mountp, agno, bno, len);
@@ -2608,6 +2606,18 @@ xfs_alloc_busy_update_extent(
        xfs_agblock_t           bbno = busyp->bno;
        xfs_agblock_t           bend = bbno + busyp->length;
 
+       /*
+        * This extent is currently being discarded.  Give the thread
+        * performing the discard a chance to mark the extent unbusy
+        * and retry.
+        */
+       if (busyp->flags & XFS_ALLOC_BUSY_DISCARDED) {
+               spin_unlock(&pag->pagb_lock);
+               delay(1);
+               spin_lock(&pag->pagb_lock);
+               return false;
+       }
+
        /*
         * If there is a busy extent overlapping a user allocation, we have
         * no choice but to force the log and retry the search.
@@ -2813,7 +2823,8 @@ restart:
                 * If this is a metadata allocation, try to reuse the busy
                 * extent instead of trimming the allocation.
                 */
-               if (!args->userdata) {
+               if (!args->userdata &&
+                   !(busyp->flags & XFS_ALLOC_BUSY_DISCARDED)) {
                        if (!xfs_alloc_busy_update_extent(args->mp, args->pag,
                                                          busyp, fbno, flen,
                                                          false))
@@ -2979,10 +2990,16 @@ xfs_alloc_busy_clear_one(
        kmem_free(busyp);
 }
 
+/*
+ * Remove all extents on the passed in list from the busy extents tree.
+ * If do_discard is set skip extents that need to be discarded, and mark
+ * these as undergoing a discard operation instead.
+ */
 void
 xfs_alloc_busy_clear(
        struct xfs_mount        *mp,
-       struct list_head        *list)
+       struct list_head        *list,
+       bool                    do_discard)
 {
        struct xfs_busy_extent  *busyp, *n;
        struct xfs_perag        *pag = NULL;
@@ -2999,7 +3016,11 @@ xfs_alloc_busy_clear(
                        agno = busyp->agno;
                }
 
-               xfs_alloc_busy_clear_one(mp, pag, busyp);
+               if (do_discard && busyp->length &&
+                   !(busyp->flags & XFS_ALLOC_BUSY_SKIP_DISCARD))
+                       busyp->flags = XFS_ALLOC_BUSY_DISCARDED;
+               else
+                       xfs_alloc_busy_clear_one(mp, pag, busyp);
        }
 
        if (pag) {