aboutsummaryrefslogtreecommitdiffstats
path: root/fs/ext4/inode.c
diff options
context:
space:
mode:
authorCurt Wohlgemuth <curtw@google.com>2011-08-13 11:25:18 -0400
committerTheodore Ts'o <tytso@mit.edu>2011-08-13 11:25:18 -0400
commit441c850857148935babe000fc2ba1455fe54a6a9 (patch)
treeaa0ef8ca32a49b2daf072f851938af3f2db35a90 /fs/ext4/inode.c
parent322a8b034003c0d46d39af85bf24fee27b902f48 (diff)
ext4: Fix ext4_should_writeback_data() for no-journal mode
ext4_should_writeback_data() had an incorrect sequence of tests to determine if it should return 0 or 1: in particular, even in no-journal mode, 0 was being returned for a non-regular-file inode. This meant that, in non-journal mode, we would use ext4_journalled_aops for directories, symlinks, and other non-regular files. However, calling journalled aop callbacks when there is no valid handle, can cause problems. This would cause a kernel crash with Jan Kara's commit 2d859db3e4 ("ext4: fix data corruption in inodes with journalled data"), because we now dereference 'handle' in ext4_journalled_write_end(). I also added BUG_ONs to check for a valid handle in the obviously journal-only aops callbacks. I tested this running xfstests with a scratch device in these modes: - no-journal - data=ordered - data=writeback - data=journal All work fine; the data=journal run has many failures and a crash in xfstests 074, but this is no different from a vanilla kernel. Signed-off-by: Curt Wohlgemuth <curtw@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@kernel.org
Diffstat (limited to 'fs/ext4/inode.c')
-rw-r--r--fs/ext4/inode.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index d47264cafee0..ad3a7ca21069 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -983,6 +983,8 @@ static int ext4_journalled_write_end(struct file *file,
983 from = pos & (PAGE_CACHE_SIZE - 1); 983 from = pos & (PAGE_CACHE_SIZE - 1);
984 to = from + len; 984 to = from + len;
985 985
986 BUG_ON(!ext4_handle_valid(handle));
987
986 if (copied < len) { 988 if (copied < len) {
987 if (!PageUptodate(page)) 989 if (!PageUptodate(page))
988 copied = 0; 990 copied = 0;
@@ -1699,6 +1701,8 @@ static int __ext4_journalled_writepage(struct page *page,
1699 goto out; 1701 goto out;
1700 } 1702 }
1701 1703
1704 BUG_ON(!ext4_handle_valid(handle));
1705
1702 ret = walk_page_buffers(handle, page_bufs, 0, len, NULL, 1706 ret = walk_page_buffers(handle, page_bufs, 0, len, NULL,
1703 do_journal_get_write_access); 1707 do_journal_get_write_access);
1704 1708