btrfs: reada_extent doesn't need kref for refcount

All increments and decrements are under the same spinlock - have to be,
since they need to protect the radix_tree it's found in.  Just use
int, no need to wank with kref...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c
index 48a4882d8ad5955eaa0be2b940e35f0b3b2a7f6f..a955669519a265bbfb5f13de4723c87932f8047e 100644 (file)
--- a/fs/btrfs/reada.c
+++ b/fs/btrfs/reada.c
@@ -68,7 +68,7 @@ struct reada_extent {
        u32                     blocksize;
        int                     err;
        struct list_head        extctl;
-       struct kref             refcnt;
+       int                     refcnt;
        spinlock_t              lock;
        struct reada_zone       *zones[BTRFS_MAX_MIRRORS];
        int                     nzones;
@@ -126,7 +126,7 @@ static int __readahead_hook(struct btrfs_root *root, struct extent_buffer *eb,
        spin_lock(&fs_info->reada_lock);
        re = radix_tree_lookup(&fs_info->reada_tree, index);
        if (re)
-               kref_get(&re->refcnt);
+               re->refcnt++;
        spin_unlock(&fs_info->reada_lock);
 
        if (!re)
@@ -336,7 +336,7 @@ static struct reada_extent *reada_find_extent(struct btrfs_root *root,
        spin_lock(&fs_info->reada_lock);
        re = radix_tree_lookup(&fs_info->reada_tree, index);
        if (re)
-               kref_get(&re->refcnt);
+               re->refcnt++;
        spin_unlock(&fs_info->reada_lock);
 
        if (re)
@@ -352,7 +352,7 @@ static struct reada_extent *reada_find_extent(struct btrfs_root *root,
        re->top = *top;
        INIT_LIST_HEAD(&re->extctl);
        spin_lock_init(&re->lock);
-       kref_init(&re->refcnt);
+       re->refcnt = 1;
 
        /*
         * map block
@@ -398,7 +398,7 @@ static struct reada_extent *reada_find_extent(struct btrfs_root *root,
        if (ret == -EEXIST) {
                re_exist = radix_tree_lookup(&fs_info->reada_tree, index);
                BUG_ON(!re_exist);
-               kref_get(&re_exist->refcnt);
+               re_exist->refcnt++;
                spin_unlock(&fs_info->reada_lock);
                goto error;
        }
@@ -465,10 +465,6 @@ error:
        return re_exist;
 }
 
-static void reada_kref_dummy(struct kref *kr)
-{
-}
-
 static void reada_extent_put(struct btrfs_fs_info *fs_info,
                             struct reada_extent *re)
 {
@@ -476,7 +472,7 @@ static void reada_extent_put(struct btrfs_fs_info *fs_info,
        unsigned long index = re->logical >> PAGE_CACHE_SHIFT;
 
        spin_lock(&fs_info->reada_lock);
-       if (!kref_put(&re->refcnt, reada_kref_dummy)) {
+       if (--re->refcnt) {
                spin_unlock(&fs_info->reada_lock);
                return;
        }
@@ -671,7 +667,7 @@ static int reada_start_machine_dev(struct btrfs_fs_info *fs_info,
                return 0;
        }
        dev->reada_next = re->logical + re->blocksize;
-       kref_get(&re->refcnt);
+       re->refcnt++;
 
        spin_unlock(&fs_info->reada_lock);