xfs: move allocation stack switch up to xfs_bmapi_allocate

[cascardo/linux.git] / fs / xfs / xfs_bmap.c

diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index 9125955..83d0cf3 100644 (file)
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -2441,7 +2441,6 @@ xfs_bmap_btalloc(
        args.tp = ap->tp;
        args.mp = mp;
        args.fsbno = ap->blkno;
-       args.stack_switch = ap->stack_switch;
 
        /* Trim the allocation back to the maximum an AG can fit. */
        args.maxlen = MIN(ap->length, XFS_ALLOC_AG_MAX_USABLE(mp));
@@ -4620,12 +4619,11 @@ xfs_bmapi_delay(
 
 
 STATIC int
-xfs_bmapi_allocate(
-       struct xfs_bmalloca     *bma,
-       int                     flags)
+__xfs_bmapi_allocate(
+       struct xfs_bmalloca     *bma)
 {
        struct xfs_mount        *mp = bma->ip->i_mount;
-       int                     whichfork = (flags & XFS_BMAPI_ATTRFORK) ?
+       int                     whichfork = (bma->flags & XFS_BMAPI_ATTRFORK) ?
                                                XFS_ATTR_FORK : XFS_DATA_FORK;
        struct xfs_ifork        *ifp = XFS_IFORK_PTR(bma->ip, whichfork);
        int                     tmp_logflags = 0;
@@ -4658,25 +4656,25 @@ xfs_bmapi_allocate(
         * Indicate if this is the first user data in the file, or just any
         * user data.
         */
-       if (!(flags & XFS_BMAPI_METADATA)) {
+       if (!(bma->flags & XFS_BMAPI_METADATA)) {
                bma->userdata = (bma->offset == 0) ?
                        XFS_ALLOC_INITIAL_USER_DATA : XFS_ALLOC_USERDATA;
        }
 
-       bma->minlen = (flags & XFS_BMAPI_CONTIG) ? bma->length : 1;
+       bma->minlen = (bma->flags & XFS_BMAPI_CONTIG) ? bma->length : 1;
 
        /*
         * Only want to do the alignment at the eof if it is userdata and
         * allocation length is larger than a stripe unit.
         */
        if (mp->m_dalign && bma->length >= mp->m_dalign &&
-           !(flags & XFS_BMAPI_METADATA) && whichfork == XFS_DATA_FORK) {
+           !(bma->flags & XFS_BMAPI_METADATA) && whichfork == XFS_DATA_FORK) {
                error = xfs_bmap_isaeof(bma, whichfork);
                if (error)
                        return error;
        }
 
-       if (flags & XFS_BMAPI_STACK_SWITCH)
+       if (bma->flags & XFS_BMAPI_STACK_SWITCH)
                bma->stack_switch = 1;
 
        error = xfs_bmap_alloc(bma);
@@ -4713,7 +4711,7 @@ xfs_bmapi_allocate(
         * A wasdelay extent has been initialized, so shouldn't be flagged
         * as unwritten.
         */
-       if (!bma->wasdel && (flags & XFS_BMAPI_PREALLOC) &&
+       if (!bma->wasdel && (bma->flags & XFS_BMAPI_PREALLOC) &&
            xfs_sb_version_hasextflgbit(&mp->m_sb))
                bma->got.br_state = XFS_EXT_UNWRITTEN;
 
@@ -4741,6 +4739,45 @@ xfs_bmapi_allocate(
        return 0;
 }
 
+static void
+xfs_bmapi_allocate_worker(
+       struct work_struct      *work)
+{
+       struct xfs_bmalloca     *args = container_of(work,
+                                               struct xfs_bmalloca, work);
+       unsigned long           pflags;
+
+       /* we are in a transaction context here */
+       current_set_flags_nested(&pflags, PF_FSTRANS);
+
+       args->result = __xfs_bmapi_allocate(args);
+       complete(args->done);
+
+       current_restore_flags_nested(&pflags, PF_FSTRANS);
+}
+
+/*
+ * Some allocation requests often come in with little stack to work on. Push
+ * them off to a worker thread so there is lots of stack to use. Otherwise just
+ * call directly to avoid the context switch overhead here.
+ */
+int
+xfs_bmapi_allocate(
+       struct xfs_bmalloca     *args)
+{
+       DECLARE_COMPLETION_ONSTACK(done);
+
+       if (!args->stack_switch)
+               return __xfs_bmapi_allocate(args);
+
+
+       args->done = &done;
+       INIT_WORK_ONSTACK(&args->work, xfs_bmapi_allocate_worker);
+       queue_work(xfs_alloc_wq, &args->work);
+       wait_for_completion(&done);
+       return args->result;
+}
+
 STATIC int
 xfs_bmapi_convert_unwritten(
        struct xfs_bmalloca     *bma,
@@ -4926,6 +4963,7 @@ xfs_bmapi_write(
                        bma.conv = !!(flags & XFS_BMAPI_CONVERT);
                        bma.wasdel = wasdelay;
                        bma.offset = bno;
+                       bma.flags = flags;
 
                        /*
                         * There's a 32/64 bit type mismatch between the
@@ -4941,7 +4979,7 @@ xfs_bmapi_write(
 
                        ASSERT(len > 0);
                        ASSERT(bma.length > 0);
-                       error = xfs_bmapi_allocate(&bma, flags);
+                       error = xfs_bmapi_allocate(&bma);
                        if (error)
                                goto error0;
                        if (bma.blkno == NULLFSBLOCK)