Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux...

[sfrench/cifs-2.6.git] / fs / btrfs / disk-io.c

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index bd0f752b797ba3c3f9f5eedb9186b304b0ac1433..983314932af3cc51260753b8acf807a98ce0988a 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -329,6 +329,8 @@ static int verify_parent_transid(struct extent_io_tree *io_tree,
 {
        struct extent_state *cached_state = NULL;
        int ret;
+       bool need_lock = (current->journal_info ==
+                         (void *)BTRFS_SEND_TRANS_STUB);
 
        if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
                return 0;
@@ -336,6 +338,11 @@ static int verify_parent_transid(struct extent_io_tree *io_tree,
        if (atomic)
                return -EAGAIN;
 
+       if (need_lock) {
+               btrfs_tree_read_lock(eb);
+               btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
+       }
+
        lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
                         0, &cached_state);
        if (extent_buffer_uptodate(eb) &&
@@ -347,10 +354,21 @@ static int verify_parent_transid(struct extent_io_tree *io_tree,
                       "found %llu\n",
                       eb->start, parent_transid, btrfs_header_generation(eb));
        ret = 1;
-       clear_extent_buffer_uptodate(eb);
+
+       /*
+        * Things reading via commit roots that don't have normal protection,
+        * like send, can have a really old block in cache that may point at a
+        * block that has been free'd and re-allocated.  So don't clear uptodate
+        * if we find an eb that is under IO (dirty/writeback) because we could
+        * end up reading in the stale data and then writing it back out and
+        * making everybody very sad.
+        */
+       if (!extent_buffer_under_io(eb))
+               clear_extent_buffer_uptodate(eb);
 out:
        unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
                             &cached_state, GFP_NOFS);
+       btrfs_tree_read_unlock_blocking(eb);
        return ret;
 }
 
@@ -1546,7 +1564,6 @@ int btrfs_init_fs_root(struct btrfs_root *root)
        root->subv_writers = writers;
 
        btrfs_init_free_ino_ctl(root);
-       mutex_init(&root->fs_commit_mutex);
        spin_lock_init(&root->cache_lock);
        init_waitqueue_head(&root->cache_wait);
 
@@ -2324,7 +2341,7 @@ int open_ctree(struct super_block *sb,
        mutex_init(&fs_info->transaction_kthread_mutex);
        mutex_init(&fs_info->cleaner_mutex);
        mutex_init(&fs_info->volume_mutex);
-       init_rwsem(&fs_info->extent_commit_sem);
+       init_rwsem(&fs_info->commit_root_sem);
        init_rwsem(&fs_info->cleanup_work_sem);
        init_rwsem(&fs_info->subvol_sem);
        sema_init(&fs_info->uuid_tree_rescan_sem, 1);
@@ -2844,7 +2861,7 @@ retry_root_backup:
                        printk(KERN_ERR "BTRFS: failed to read log tree\n");
                        free_extent_buffer(log_tree_root->node);
                        kfree(log_tree_root);
-                       goto fail_trans_kthread;
+                       goto fail_qgroup;
                }
                /* returns with log_tree_root freed on success */
                ret = btrfs_recover_log_trees(log_tree_root);
@@ -2853,24 +2870,24 @@ retry_root_backup:
                                    "Failed to recover log tree");
                        free_extent_buffer(log_tree_root->node);
                        kfree(log_tree_root);
-                       goto fail_trans_kthread;
+                       goto fail_qgroup;
                }
 
                if (sb->s_flags & MS_RDONLY) {
                        ret = btrfs_commit_super(tree_root);
                        if (ret)
-                               goto fail_trans_kthread;
+                               goto fail_qgroup;
                }
        }
 
        ret = btrfs_find_orphan_roots(tree_root);
        if (ret)
-               goto fail_trans_kthread;
+               goto fail_qgroup;
 
        if (!(sb->s_flags & MS_RDONLY)) {
                ret = btrfs_cleanup_fs_roots(fs_info);
                if (ret)
-                       goto fail_trans_kthread;
+                       goto fail_qgroup;
 
                ret = btrfs_recover_relocation(tree_root);
                if (ret < 0) {