cstyle: Resolve C style issues

[mirror_zfs.git] / module / zfs / vdev_cache.c

diff --git a/module/zfs/vdev_cache.c b/module/zfs/vdev_cache.c
index 0d1fe7d2c38563255e5680286a4e5384d1f53cc6..ffd50ec2fddbbcbdf9ef8655afe6e2abd5ab5195 100644 (file)
--- a/module/zfs/vdev_cache.c
+++ b/module/zfs/vdev_cache.c
@@ -22,6 +22,9 @@
  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
+/*
+ * Copyright (c) 2013 by Delphix. All rights reserved.
+ */
 
 #include <sys/zfs_context.h>
 #include <sys/spa.h>
@@ -71,9 +74,16 @@
  * 1<<zfs_vdev_cache_bshift byte reads by the vdev_cache (aka software
  * track buffer).  At most zfs_vdev_cache_size bytes will be kept in each
  * vdev's vdev_cache.
+ *
+ * TODO: Note that with the current ZFS code, it turns out that the
+ * vdev cache is not helpful, and in some cases actually harmful.  It
+ * is better if we disable this.  Once some time has passed, we should
+ * actually remove this to simplify the code.  For now we just disable
+ * it by setting the zfs_vdev_cache_size to zero.  Note that Solaris 11
+ * has made these same changes.
  */
 int zfs_vdev_cache_max = 1<<14;                        /* 16KB */
-int zfs_vdev_cache_size = 10ULL << 20;         /* 10MB */
+int zfs_vdev_cache_size = 0;
 int zfs_vdev_cache_bshift = 16;
 
 #define        VCBS (1 << zfs_vdev_cache_bshift)       /* 64KB */
@@ -170,7 +180,7 @@ vdev_cache_allocate(zio_t *zio)
                vdev_cache_evict(vc, ve);
        }
 
-       ve = kmem_zalloc(sizeof (vdev_cache_entry_t), KM_SLEEP);
+       ve = kmem_zalloc(sizeof (vdev_cache_entry_t), KM_PUSHPAGE);
        ve->ve_offset = offset;
        ve->ve_lastused = ddi_get_lbolt();
        ve->ve_data = zio_buf_alloc(VCBS);
@@ -246,36 +256,36 @@ vdev_cache_read(zio_t *zio)
        vdev_cache_t *vc = &zio->io_vd->vdev_cache;
        vdev_cache_entry_t *ve, *ve_search;
        uint64_t cache_offset = P2ALIGN(zio->io_offset, VCBS);
-       ASSERTV(uint64_t cache_phase = P2PHASE(zio->io_offset, VCBS);)
        zio_t *fio;
+       ASSERTV(uint64_t cache_phase = P2PHASE(zio->io_offset, VCBS));
 
        ASSERT(zio->io_type == ZIO_TYPE_READ);
 
        if (zio->io_flags & ZIO_FLAG_DONT_CACHE)
-               return (EINVAL);
+               return (SET_ERROR(EINVAL));
 
        if (zio->io_size > zfs_vdev_cache_max)
-               return (EOVERFLOW);
+               return (SET_ERROR(EOVERFLOW));
 
        /*
         * If the I/O straddles two or more cache blocks, don't cache it.
         */
        if (P2BOUNDARY(zio->io_offset, zio->io_size, VCBS))
-               return (EXDEV);
+               return (SET_ERROR(EXDEV));
 
        ASSERT(cache_phase + zio->io_size <= VCBS);
 
        mutex_enter(&vc->vc_lock);
 
-       ve_search = kmem_alloc(sizeof(vdev_cache_entry_t), KM_SLEEP);
+       ve_search = kmem_alloc(sizeof (vdev_cache_entry_t), KM_PUSHPAGE);
        ve_search->ve_offset = cache_offset;
        ve = avl_find(&vc->vc_offset_tree, ve_search, NULL);
-       kmem_free(ve_search, sizeof(vdev_cache_entry_t));
+       kmem_free(ve_search, sizeof (vdev_cache_entry_t));
 
        if (ve != NULL) {
                if (ve->ve_missed_update) {
                        mutex_exit(&vc->vc_lock);
-                       return (ESTALE);
+                       return (SET_ERROR(ESTALE));
                }
 
                if ((fio = ve->ve_fill_io) != NULL) {
@@ -298,11 +308,11 @@ vdev_cache_read(zio_t *zio)
 
        if (ve == NULL) {
                mutex_exit(&vc->vc_lock);
-               return (ENOMEM);
+               return (SET_ERROR(ENOMEM));
        }
 
        fio = zio_vdev_delegated_io(zio->io_vd, cache_offset,
-           ve->ve_data, VCBS, ZIO_TYPE_READ, ZIO_PRIORITY_CACHE_FILL,
+           ve->ve_data, VCBS, ZIO_TYPE_READ, ZIO_PRIORITY_NOW,
            ZIO_FLAG_DONT_CACHE, vdev_cache_fill, ve);
 
        ve->ve_fill_io = fio;