Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg...

[linux-2.6-omap-h63xx.git] / fs / btrfs / extent-tree.c

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 9abf81f71c46582db63b89c26d4e952651e3a1ee..fefe83ad20595eba078f6480781eefb0fe81c659 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -20,6 +20,7 @@
 #include <linux/writeback.h>
 #include <linux/blkdev.h>
 #include <linux/sort.h>
+#include <linux/rcupdate.h>
 #include "compat.h"
 #include "hash.h"
 #include "crc32c.h"
@@ -330,13 +331,33 @@ static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
 {
        struct list_head *head = &info->space_info;
        struct btrfs_space_info *found;
-       list_for_each_entry(found, head, list) {
-               if (found->flags == flags)
+
+       rcu_read_lock();
+       list_for_each_entry_rcu(found, head, list) {
+               if (found->flags == flags) {
+                       rcu_read_unlock();
                        return found;
+               }
        }
+       rcu_read_unlock();
        return NULL;
 }
 
+/*
+ * after adding space to the filesystem, we need to clear the full flags
+ * on all the space infos.
+ */
+void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
+{
+       struct list_head *head = &info->space_info;
+       struct btrfs_space_info *found;
+
+       rcu_read_lock();
+       list_for_each_entry_rcu(found, head, list)
+               found->full = 0;
+       rcu_read_unlock();
+}
+
 static u64 div_factor(u64 num, int factor)
 {
        if (factor == 10)
@@ -1903,7 +1924,6 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags,
        if (!found)
                return -ENOMEM;
 
-       list_add(&found->list, &info->space_info);
        INIT_LIST_HEAD(&found->block_groups);
        init_rwsem(&found->groups_sem);
        spin_lock_init(&found->lock);
@@ -1917,6 +1937,7 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags,
        found->full = 0;
        found->force_alloc = 0;
        *space_info = found;
+       list_add_rcu(&found->list, &info->space_info);
        return 0;
 }
 
@@ -6320,6 +6341,7 @@ out:
 int btrfs_free_block_groups(struct btrfs_fs_info *info)
 {
        struct btrfs_block_group_cache *block_group;
+       struct btrfs_space_info *space_info;
        struct rb_node *n;
 
        spin_lock(&info->block_group_cache_lock);
@@ -6341,6 +6363,23 @@ int btrfs_free_block_groups(struct btrfs_fs_info *info)
                spin_lock(&info->block_group_cache_lock);
        }
        spin_unlock(&info->block_group_cache_lock);
+
+       /* now that all the block groups are freed, go through and
+        * free all the space_info structs.  This is only called during
+        * the final stages of unmount, and so we know nobody is
+        * using them.  We call synchronize_rcu() once before we start,
+        * just to be on the safe side.
+        */
+       synchronize_rcu();
+
+       while(!list_empty(&info->space_info)) {
+               space_info = list_entry(info->space_info.next,
+                                       struct btrfs_space_info,
+                                       list);
+
+               list_del(&space_info->list);
+               kfree(space_info);
+       }
        return 0;
 }