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 9b3a9f5a26031e14b10d6c0e8c1d115d95350132..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 */
@@ -170,9 +180,9 @@ 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 = lbolt;
+       ve->ve_lastused = ddi_get_lbolt();
        ve->ve_data = zio_buf_alloc(VCBS);
 
        avl_add(&vc->vc_offset_tree, ve);
@@ -189,9 +199,9 @@ vdev_cache_hit(vdev_cache_t *vc, vdev_cache_entry_t *ve, zio_t *zio)
        ASSERT(MUTEX_HELD(&vc->vc_lock));
        ASSERT(ve->ve_fill_io == NULL);
 
-       if (ve->ve_lastused != lbolt) {
+       if (ve->ve_lastused != ddi_get_lbolt()) {
                avl_remove(&vc->vc_lastused_tree, ve);
-               ve->ve_lastused = lbolt;
+               ve->ve_lastused = ddi_get_lbolt();
                avl_add(&vc->vc_lastused_tree, ve);
        }
 
@@ -244,36 +254,38 @@ int
 vdev_cache_read(zio_t *zio)
 {
        vdev_cache_t *vc = &zio->io_vd->vdev_cache;
-       vdev_cache_entry_t *ve, ve_search;
+       vdev_cache_entry_t *ve, *ve_search;
        uint64_t cache_offset = P2ALIGN(zio->io_offset, VCBS);
-       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.ve_offset = cache_offset;
-       ve = avl_find(&vc->vc_offset_tree, &ve_search, NULL);
+       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));
 
        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) {
@@ -296,11 +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;
@@ -414,3 +426,14 @@ vdev_cache_stat_fini(void)
                vdc_ksp = NULL;
        }
 }
+
+#if defined(_KERNEL) && defined(HAVE_SPL)
+module_param(zfs_vdev_cache_max, int, 0644);
+MODULE_PARM_DESC(zfs_vdev_cache_max, "Inflate reads small than max");
+
+module_param(zfs_vdev_cache_size, int, 0444);
+MODULE_PARM_DESC(zfs_vdev_cache_size, "Total size of the per-disk cache");
+
+module_param(zfs_vdev_cache_bshift, int, 0644);
+MODULE_PARM_DESC(zfs_vdev_cache_bshift, "Shift size to inflate reads too");
+#endif