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

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

6 files changed, 21 insertions, 6 deletions

diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 5ba83894c8b..40b4e0c9cd0 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -30,6 +30,7 @@ struct btrfs_inode {
         struct extent_map_tree extent_tree;
         struct extent_io_tree io_tree;
         struct extent_io_tree io_failure_tree;
+        struct mutex csum_mutex;
         struct inode vfs_inode;
         atomic_t ordered_writeback;
 
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index ece221cba90..8037792f878 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -267,13 +267,13 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
 
         /* FIXME...EIEIO, ENOSPC and more */
         /* insert any holes we need to create */
-        if (isize < end_pos) {
+        if (isize < start_pos) {
                 u64 last_pos_in_file;
                 u64 hole_size;
                 u64 mask = root->sectorsize - 1;
                 last_pos_in_file = (isize + mask) & ~mask;
-                hole_size = (end_pos - last_pos_in_file + mask) & ~mask;
-                if (last_pos_in_file < end_pos) {
+                hole_size = (start_pos - last_pos_in_file + mask) & ~mask;
+                if (last_pos_in_file < start_pos) {
                         err = btrfs_drop_extents(trans, root, inode,
                                                  last_pos_in_file,
                                                  last_pos_in_file + hole_size,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index bbba3350d02..d39433dfb2c 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;
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 5e4c0d95ce4..254da822566 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -152,12 +152,13 @@ int btrfs_add_ordered_inode(struct inode *inode)
                            inode->i_ino, &entry->rb_node);
 
         BTRFS_I(inode)->ordered_trans = transid;
+        if (!node)
+                igrab(inode);
 
         write_unlock(&tree->lock);
+
         if (node)
                 kfree(entry);
-        else
-                igrab(inode);
         return 0;
 }
 
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 0c53ff775b9..8e909cb97c6 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -477,7 +477,7 @@ static noinline int drop_dirty_roots(struct btrfs_root *tree_root,
                         if (err)
                                 ret = err;
                         nr = trans->blocks_used;
-                        ret = btrfs_end_transaction(trans, tree_root);
+                        ret = btrfs_end_transaction_throttle(trans, tree_root);
                         BUG_ON(ret);
 
                         mutex_unlock(&root->fs_info->drop_mutex);
diff --git a/fs/btrfs/tree-defrag.c b/fs/btrfs/tree-defrag.c
index 1677e4edaf6..b17693f61fb 100644
--- a/fs/btrfs/tree-defrag.c
+++ b/fs/btrfs/tree-defrag.c
@@ -38,8 +38,15 @@ int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
         u64 last_ret = 0;
 
         if (root->fs_info->extent_root == root) {
+                /*
+                 * there's recursion here right now in the tree locking,
+                 * we can't defrag the extent root without deadlock
+                 */
+                goto out;
+#if 0
                 mutex_lock(&root->fs_info->alloc_mutex);
                 is_extent = 1;
+#endif
         }
 
         if (root->ref_cows == 0 && !is_extent)