From: Chris Mason <chris.mason@oracle.com>
Date: Tue, 19 Feb 2008 17:55:05 +0000 (-0500)
Subject: Btrfs: Take the extent lock before dropping the delalloc bits
X-Git-Tag: firefly_0821_release~15789^2~11^2~55^2~56^2~30^2~280
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=d99cb30a11ea117ad0f58cda09aa43438ebbf81c;p=firefly-linux-kernel-4.4.55.git

Btrfs: Take the extent lock before dropping the delalloc bits

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

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 1a47251a9d4d..51466dcd44e0 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -765,9 +765,13 @@ static int prepare_pages(struct btrfs_root *root, struct file *file,
 	if (start_pos < inode->i_size) {
 		u64 last_pos;
 		last_pos = (index + num_pages) << PAGE_CACHE_SHIFT;
+		lock_extent(&BTRFS_I(inode)->io_tree,
+			    start_pos, last_pos - 1, GFP_NOFS);
 		clear_extent_bits(&BTRFS_I(inode)->io_tree, start_pos,
 				  last_pos - 1, EXTENT_DIRTY | EXTENT_DELALLOC,
 				  GFP_NOFS);
+		unlock_extent(&BTRFS_I(inode)->io_tree,
+			      start_pos, last_pos - 1, GFP_NOFS);
 	}
 	return 0;
 }