[PATCH v4 16/27] fs: adapt sync_file_range to new reporting infrastructure

[Jeff Layton <jlayton@redhat.com>]

Since it returns errors in a way similar to fsync, have it use the same
method for returning previously-reported writeback errors.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
 fs/sync.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/fs/sync.c b/fs/sync.c
index 11ba023434b1..89a03b5252d2 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -271,8 +271,11 @@ SYSCALL_DEFINE1(fdatasync, unsigned int, fd)
  *
  *
  * SYNC_FILE_RANGE_WAIT_BEFORE and SYNC_FILE_RANGE_WAIT_AFTER will detect any
- * I/O errors or ENOSPC conditions and will return those to the caller, after
- * clearing the EIO and ENOSPC flags in the address_space.
+ * error condition that occurred prior to or after writeback, and will return
+ * that to the caller, while advancing the file's errseq_t cursor. Note that
+ * any errors returned here may have occurred in an area of the file that is
+ * not covered by the given range as most filesystems track writeback errors
+ * on a per-address_space basis
  *
  * It should be noted that none of these operations write out the file's
  * metadata.  So unless the application is strictly performing overwrites of
@@ -282,7 +285,7 @@ SYSCALL_DEFINE1(fdatasync, unsigned int, fd)
 SYSCALL_DEFINE4(sync_file_range, int, fd, loff_t, offset, loff_t, nbytes,
 				unsigned int, flags)
 {
-	int ret;
+	int ret, ret2;
 	struct fd f;
 	struct address_space *mapping;
 	loff_t endbyte;			/* inclusive */
@@ -356,7 +359,9 @@ SYSCALL_DEFINE4(sync_file_range, int, fd, loff_t, offset, loff_t, nbytes,
 
 	if (flags & SYNC_FILE_RANGE_WAIT_AFTER)
 		ret = filemap_fdatawait_range(mapping, offset, endbyte);
-
+	ret2 = filemap_report_wb_error(f.file);
+	if (!ret)
+		ret = ret2;
 out_put:
 	fdput(f);
 out:
-- 
2.9.3