direct I/O fallback sync simplification
In the case of direct I/O falling back to buffered I/O we sync data
twice currently: once at the end of generic_file_buffered_write using
filemap_write_and_wait_range and once a little later in
__generic_file_aio_write using do_sync_mapping_range with all flags set.
The wait before write of the do_sync_mapping_range call does not make
any sense, so just keep the filemap_write_and_wait_range call and move
it to the right spot.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/mm/filemap.c b/mm/filemap.c
index 8b4d88f..96ac6b0 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2240,7 +2240,6 @@
size_t count, ssize_t written)
{
struct file *file = iocb->ki_filp;
- struct address_space *mapping = file->f_mapping;
ssize_t status;
struct iov_iter i;
@@ -2252,15 +2251,6 @@
*ppos = pos + status;
}
- /*
- * If we get here for O_DIRECT writes then we must have fallen through
- * to buffered writes (block instantiation inside i_size). So we sync
- * the file data here, to try to honour O_DIRECT expectations.
- */
- if (unlikely(file->f_flags & O_DIRECT) && written)
- status = filemap_write_and_wait_range(mapping,
- pos, pos + written - 1);
-
return written ? written : status;
}
EXPORT_SYMBOL(generic_file_buffered_write);
@@ -2359,10 +2349,7 @@
* semantics.
*/
endbyte = pos + written_buffered - written - 1;
- err = do_sync_mapping_range(file->f_mapping, pos, endbyte,
- SYNC_FILE_RANGE_WAIT_BEFORE|
- SYNC_FILE_RANGE_WRITE|
- SYNC_FILE_RANGE_WAIT_AFTER);
+ err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte);
if (err == 0) {
written = written_buffered;
invalidate_mapping_pages(mapping,