From: Chris Mason <chris.mason@oracle.com>
Date: Mon, 10 Nov 2008 12:31:30 +0000 (-0500)
Subject: Btrfs: Make sure pages are dirty before doing delalloc for them
X-Git-Tag: firefly_0821_release~15789^2~11^2~55^2~32
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f2b1c41cf94d7f839fe9ede5f3ead92698a93fb3;p=firefly-linux-kernel-4.4.55.git

Btrfs: Make sure pages are dirty before doing delalloc for them

This adds a PageDirty check to the writeback path that locks pages
for delalloc.  If a page wasn't dirty at this point, it is in the
process of being truncated away.

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

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index ad75a9cc3604..69ea09659d47 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1205,7 +1205,8 @@ static noinline int lock_delalloc_pages(struct inode *inode,
 			 */
 			if (pages[i] != locked_page) {
 				lock_page(pages[i]);
-				if (pages[i]->mapping != inode->i_mapping) {
+				if (!PageDirty(pages[i]) ||
+				    pages[i]->mapping != inode->i_mapping) {
 					ret = -EAGAIN;
 					unlock_page(pages[i]);
 					page_cache_release(pages[i]);