Btrfs: extent_map and data=ordered fixes for space balancing
* Add an EXTENT_BOUNDARY state bit to keep the writepage code
from merging data extents that are in the process of being
relocated. This allows us to do accounting for them properly.
* The balancing code relocates data extents indepdent of the underlying
inode. The extent_map code was modified to properly account for
things moving around (invalidating extent_map caches in the inode).
* Don't take the drop_mutex in the create_subvol ioctl. It isn't
required.
* Fix walking of the ordered extent list to avoid races with sys_unlink
* Change the lock ordering rules. Transaction start goes outside
the drop_mutex. This allows btrfs_commit_transaction to directly
drop the relocation trees.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 50aea8c..f9cd409 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -290,7 +290,6 @@
struct extent_buffer **cow_ret, u64 prealloc_dest)
{
u64 search_start;
- u64 header_trans;
int ret;
if (trans->transaction != root->fs_info->running_transaction) {
@@ -304,9 +303,9 @@
WARN_ON(1);
}
- header_trans = btrfs_header_generation(buf);
spin_lock(&root->fs_info->hash_lock);
- if (header_trans == trans->transid &&
+ if (btrfs_header_generation(buf) == trans->transid &&
+ btrfs_header_owner(buf) == root->root_key.objectid &&
!btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
*cow_ret = buf;
spin_unlock(&root->fs_info->hash_lock);
@@ -1300,6 +1299,7 @@
/* is a cow on this block not required */
spin_lock(&root->fs_info->hash_lock);
if (btrfs_header_generation(b) == trans->transid &&
+ btrfs_header_owner(b) == root->root_key.objectid &&
!btrfs_header_flag(b, BTRFS_HEADER_FLAG_WRITTEN)) {
spin_unlock(&root->fs_info->hash_lock);
goto cow_done;
@@ -1396,7 +1396,8 @@
/* this is only true while dropping a snapshot */
if (level == lowest_level) {
- break;
+ ret = 0;
+ goto done;
}
blocknr = btrfs_node_blockptr(b, slot);