ext4: fake direct I/O mode for data=journal
Currently attempts to open a file with O_DIRECT in data=journal mode
causes the open to fail with -EINVAL. This makes it very hard to test
data=journal mode. So we will let the open succeed, but then always
fall back to O_DSYNC buffered writes.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 18d2558..b84f127 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2854,6 +2854,12 @@
struct inode *inode = file->f_mapping->host;
ssize_t ret;
+ /*
+ * If we are doing data journalling we don't support O_DIRECT
+ */
+ if (ext4_should_journal_data(inode))
+ return 0;
+
trace_ext4_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw);
if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
ret = ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs);
@@ -2923,6 +2929,7 @@
.bmap = ext4_bmap,
.invalidatepage = ext4_invalidatepage,
.releasepage = ext4_releasepage,
+ .direct_IO = ext4_direct_IO,
.is_partially_uptodate = block_is_partially_uptodate,
.error_remove_page = generic_error_remove_page,
};