Btrfs: Add a per-inode csum mutex to avoid races creating csum items

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index bbba3350d023..d39433dfb2c7 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -351,7 +351,9 @@ int __btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
         trans = btrfs_start_transaction(root, 1);
 
         btrfs_set_trans_block_group(trans, inode);
+        mutex_lock(&BTRFS_I(inode)->csum_mutex);
         btrfs_csum_file_blocks(trans, root, inode, bio, sums);
+        mutex_unlock(&BTRFS_I(inode)->csum_mutex);
 
         ret = btrfs_end_transaction(trans, root);
         BUG_ON(ret);
@@ -1400,6 +1402,7 @@ static int btrfs_init_locked_inode(struct inode *inode, void *p)
                              inode->i_mapping, GFP_NOFS);
         extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
                              inode->i_mapping, GFP_NOFS);
+        mutex_init(&BTRFS_I(inode)->csum_mutex);
         atomic_set(&BTRFS_I(inode)->ordered_writeback, 0);
         return 0;
 }
@@ -1701,6 +1704,7 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
                              inode->i_mapping, GFP_NOFS);
         extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
                              inode->i_mapping, GFP_NOFS);
+        mutex_init(&BTRFS_I(inode)->csum_mutex);
         atomic_set(&BTRFS_I(inode)->ordered_writeback, 0);
         BTRFS_I(inode)->delalloc_bytes = 0;
         BTRFS_I(inode)->root = root;
@@ -1924,6 +1928,7 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
                                      inode->i_mapping, GFP_NOFS);
                 extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
                                      inode->i_mapping, GFP_NOFS);
+                mutex_init(&BTRFS_I(inode)->csum_mutex);
                 BTRFS_I(inode)->delalloc_bytes = 0;
                 atomic_set(&BTRFS_I(inode)->ordered_writeback, 0);
                 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
@@ -2862,6 +2867,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
                                      inode->i_mapping, GFP_NOFS);
                 extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
                                      inode->i_mapping, GFP_NOFS);
+                mutex_init(&BTRFS_I(inode)->csum_mutex);
                 BTRFS_I(inode)->delalloc_bytes = 0;
                 atomic_set(&BTRFS_I(inode)->ordered_writeback, 0);
                 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;