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authorYan Zheng <zheng.yan@oracle.com>2009-07-22 18:07:05 +0400
committerChris Mason <chris.mason@oracle.com>2009-07-22 18:07:05 +0400
commit4a8c9a62d7f7f058eed4b8a6f2c890a887778093 (patch)
treed3d099197e5ddc94f737dbad273810b902b05307
parent33c66f430bfa3a033e70470e4c93f967156b696d (diff)
downloadlinux-4a8c9a62d7f7f058eed4b8a6f2c890a887778093.tar.xz
Btrfs: make sure all dirty blocks are written at commit time
Write dirty block groups may allocate new block, and so may add new delayed back ref. btrfs_run_delayed_refs may make some block groups dirty. commit_cowonly_roots does not handle the recursion properly, and some dirty blocks can be left unwritten at commit time. This patch moves btrfs_run_delayed_refs into the loop that writes dirty block groups, and makes the code not break out of the loop until there are no dirty block groups or delayed back refs. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
-rw-r--r--fs/btrfs/extent-tree.c70
-rw-r--r--fs/btrfs/transaction.c9
2 files changed, 42 insertions, 37 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a5aca3997d42..62a332d34fdb 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2387,13 +2387,29 @@ fail:
}
+static struct btrfs_block_group_cache *
+next_block_group(struct btrfs_root *root,
+ struct btrfs_block_group_cache *cache)
+{
+ struct rb_node *node;
+ spin_lock(&root->fs_info->block_group_cache_lock);
+ node = rb_next(&cache->cache_node);
+ btrfs_put_block_group(cache);
+ if (node) {
+ cache = rb_entry(node, struct btrfs_block_group_cache,
+ cache_node);
+ atomic_inc(&cache->count);
+ } else
+ cache = NULL;
+ spin_unlock(&root->fs_info->block_group_cache_lock);
+ return cache;
+}
+
int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
- struct btrfs_block_group_cache *cache, *entry;
- struct rb_node *n;
+ struct btrfs_block_group_cache *cache;
int err = 0;
- int werr = 0;
struct btrfs_path *path;
u64 last = 0;
@@ -2402,39 +2418,35 @@ int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
return -ENOMEM;
while (1) {
- cache = NULL;
- spin_lock(&root->fs_info->block_group_cache_lock);
- for (n = rb_first(&root->fs_info->block_group_cache_tree);
- n; n = rb_next(n)) {
- entry = rb_entry(n, struct btrfs_block_group_cache,
- cache_node);
- if (entry->dirty) {
- cache = entry;
- break;
- }
+ if (last == 0) {
+ err = btrfs_run_delayed_refs(trans, root,
+ (unsigned long)-1);
+ BUG_ON(err);
}
- spin_unlock(&root->fs_info->block_group_cache_lock);
- if (!cache)
- break;
+ cache = btrfs_lookup_first_block_group(root->fs_info, last);
+ while (cache) {
+ if (cache->dirty)
+ break;
+ cache = next_block_group(root, cache);
+ }
+ if (!cache) {
+ if (last == 0)
+ break;
+ last = 0;
+ continue;
+ }
cache->dirty = 0;
- last += cache->key.offset;
+ last = cache->key.objectid + cache->key.offset;
- err = write_one_cache_group(trans, root,
- path, cache);
- /*
- * if we fail to write the cache group, we want
- * to keep it marked dirty in hopes that a later
- * write will work
- */
- if (err) {
- werr = err;
- continue;
- }
+ err = write_one_cache_group(trans, root, path, cache);
+ BUG_ON(err);
+ btrfs_put_block_group(cache);
}
+
btrfs_free_path(path);
- return werr;
+ return 0;
}
int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 2dbf1c1f56ee..81f7124c3051 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -444,9 +444,6 @@ static int update_cowonly_root(struct btrfs_trans_handle *trans,
btrfs_write_dirty_block_groups(trans, root);
- ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
- BUG_ON(ret);
-
while (1) {
old_root_bytenr = btrfs_root_bytenr(&root->root_item);
if (old_root_bytenr == root->node->start)
@@ -457,9 +454,8 @@ static int update_cowonly_root(struct btrfs_trans_handle *trans,
&root->root_key,
&root->root_item);
BUG_ON(ret);
- btrfs_write_dirty_block_groups(trans, root);
- ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
+ ret = btrfs_write_dirty_block_groups(trans, root);
BUG_ON(ret);
}
free_extent_buffer(root->commit_root);
@@ -495,9 +491,6 @@ static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans,
root = list_entry(next, struct btrfs_root, dirty_list);
update_cowonly_root(trans, root);
-
- ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
- BUG_ON(ret);
}
return 0;
}