summaryrefslogtreecommitdiff
path: root/mm
diff options
context:
space:
mode:
authorAl Viro <viro@zeniv.linux.org.uk>2014-02-09 15:18:09 -0500
committerJiri Slaby <jslaby@suse.cz>2014-12-03 11:58:41 +0100
commit79a423edd0ce526b6a28fd1fed4478d0ecda03e0 (patch)
tree4746b0e55a311b6cfe274b262534f70a1543348c /mm
parentf39a6f3d592372cd369b6a04a8562f3e6f41ee47 (diff)
fix O_SYNC|O_APPEND syncing the wrong range on write()
commit d311d79de305f1ada47cadd672e6ed1b28a949eb upstream. It actually goes back to 2004 ([PATCH] Concurrent O_SYNC write support) when sync_page_range() had been introduced; generic_file_write{,v}() correctly synced pos_after_write - written .. pos_after_write - 1 but generic_file_aio_write() synced pos_before_write .. pos_before_write + written - 1 instead. Which is not the same thing with O_APPEND, obviously. A couple of years later correct variant had been killed off when everything switched to use of generic_file_aio_write(). All users of generic_file_aio_write() are affected, and the same bug has been copied into other instances of ->aio_write(). The fix is trivial; the only subtle point is that generic_write_sync() ought to be inlined to avoid calculations useless for the majority of calls. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'mm')
-rw-r--r--mm/filemap.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index b012daefc2d7..e94c70380deb 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2723,8 +2723,8 @@ ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
if (ret > 0) {
ssize_t err;
- err = generic_write_sync(file, pos, ret);
- if (err < 0 && ret > 0)
+ err = generic_write_sync(file, iocb->ki_pos - ret, ret);
+ if (err < 0)
ret = err;
}
return ret;