Btrfs: Fix data=ordered vs wait_on_inode deadlock on older kernels
Using ilookup5 during data=ordered writeback could deadlock on I_LOCK. This
saves a pointer to the inode instead.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 08f7a18..b6bbfc1 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -490,19 +490,17 @@
while(1) {
ret = btrfs_find_first_ordered_inode(
&cur_trans->ordered_inode_tree,
- &root_objectid, &objectid);
+ &root_objectid, &objectid, &inode);
if (!ret)
break;
mutex_unlock(&root->fs_info->trans_mutex);
mutex_unlock(&root->fs_info->fs_mutex);
- inode = btrfs_ilookup(root->fs_info->sb, objectid,
- root_objectid);
- if (inode) {
- if (S_ISREG(inode->i_mode))
- filemap_fdatawrite(inode->i_mapping);
- iput(inode);
- }
+
+ if (S_ISREG(inode->i_mode))
+ filemap_fdatawrite(inode->i_mapping);
+ iput(inode);
+
mutex_lock(&root->fs_info->fs_mutex);
mutex_lock(&root->fs_info->trans_mutex);
}
@@ -511,19 +509,17 @@
objectid = 0;
ret = btrfs_find_del_first_ordered_inode(
&cur_trans->ordered_inode_tree,
- &root_objectid, &objectid);
+ &root_objectid, &objectid, &inode);
if (!ret)
break;
mutex_unlock(&root->fs_info->trans_mutex);
mutex_unlock(&root->fs_info->fs_mutex);
- inode = btrfs_ilookup(root->fs_info->sb, objectid,
- root_objectid);
- if (inode) {
- if (S_ISREG(inode->i_mode))
- filemap_write_and_wait(inode->i_mapping);
- atomic_dec(&inode->i_count);
- iput(inode);
- }
+
+ if (S_ISREG(inode->i_mode))
+ filemap_write_and_wait(inode->i_mapping);
+ atomic_dec(&inode->i_count);
+ iput(inode);
+
mutex_lock(&root->fs_info->fs_mutex);
mutex_lock(&root->fs_info->trans_mutex);
}