btrfs file write debugging patch

Commit Message

Chris Mason March 4, 2011, 1:51 a.m. UTC

None

Patch

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 89a6a26..6a44add 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1039,6 +1038,14 @@  static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
 
 		copied = btrfs_copy_from_user(pos, num_pages,
 					   write_bytes, pages, &i);
+
+		/*
+		 * if we have trouble faulting in the pages, fall
+		 * back to one page at a time
+		 */
+		if (copied < write_bytes)
+			nrptrs = 1;
+
 		if (copied == 0)
 			dirty_pages = 0;
 		else