xfs: add online discard support

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

diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index acdced8..721db22 100644 (file)
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -2608,6 +2608,18 @@ 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 +2825,8 @@ 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 +2992,16 @@ 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 +3018,10 @@ 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_DISCARDED;
+               else
+                       xfs_alloc_busy_clear_one(mp, pag, busyp);
        }
 
        if (pag) {