Joseph Qi
2015-Jan-20 08:10 UTC
[Ocfs2-devel] [PATCH 7/9 v6] ocfs2: complete the rest request through buffer io
Complte the rest request thourgh buffer io after direct write performed.
Signed-off-by: Joseph Qi <joseph.qi at huawei.com>
Cc: Weiwei Wang <wangww631 at huawei.com>
---
fs/ocfs2/file.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 42 insertions(+), 1 deletion(-)
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index c1446cf..4a712cf 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2253,6 +2253,7 @@ static ssize_t ocfs2_file_write_iter(struct kiocb *iocb,
u32 old_clusters;
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
+ struct address_space *mapping = file->f_mapping;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
int full_coherency = !(osb->s_mount_opt &
OCFS2_MOUNT_COHERENCY_BUFFERED);
@@ -2367,11 +2368,51 @@ relock:
iov_iter_truncate(from, count);
if (direct_io) {
+ loff_t endbyte;
+ ssize_t written_buffered;
written = generic_file_direct_write(iocb, from, *ppos);
- if (written < 0) {
+ if (written < 0 || written == count) {
ret = written;
goto out_dio;
}
+
+ /*
+ * for completing the rest of the request.
+ */
+ *ppos += written;
+ count -= written;
+ written_buffered = generic_perform_write(file, from, *ppos);
+ /*
+ * If generic_file_buffered_write() returned a synchronous error
+ * then we want to return the number of bytes which were
+ * direct-written, or the error code if that was zero. Note
+ * that this differs from normal direct-io semantics, which
+ * will return -EFOO even if some bytes were written.
+ */
+ if (written_buffered < 0) {
+ ret = written_buffered;
+ goto out_dio;
+ }
+
+ iocb->ki_pos = *ppos + written_buffered;
+ /* We need to ensure that the page cache pages are written to
+ * disk and invalidated to preserve the expected O_DIRECT
+ * semantics.
+ */
+ endbyte = *ppos + written_buffered - 1;
+ ret = filemap_write_and_wait_range(file->f_mapping, *ppos,
+ endbyte);
+ if (ret == 0) {
+ written += written_buffered;
+ invalidate_mapping_pages(mapping,
+ *ppos >> PAGE_CACHE_SHIFT,
+ endbyte >> PAGE_CACHE_SHIFT);
+ } else {
+ /*
+ * We don't know how much we wrote, so just return
+ * the number of bytes which were direct-written
+ */
+ }
} else {
current->backing_dev_info = file->f_mapping->backing_dev_info;
written = generic_perform_write(file, from, *ppos);
--
1.8.4.3