ceph: return the real size read when it hits EOF
Currently, if the sync read handler ends up reading more from the last
object in the file than the i_size indicates, then it'll end up
returning the wrong length. Ensure that we cap the returned length and
pos at the EOF.
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 91173d3..6005b43 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -847,6 +847,7 @@ static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *to,
ssize_t ret;
u64 off = iocb->ki_pos;
u64 len = iov_iter_count(to);
+ u64 i_size;
dout("sync_read on file %p %llu~%u %s\n", file, off, (unsigned)len,
(file->f_flags & O_DIRECT) ? "O_DIRECT" : "");
@@ -870,7 +871,6 @@ static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *to,
struct page **pages;
int num_pages;
size_t page_off;
- u64 i_size;
bool more;
int idx;
size_t left;
@@ -953,11 +953,14 @@ static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *to,
}
if (off > iocb->ki_pos) {
- if (ret >= 0 &&
- iov_iter_count(to) > 0 && off >= i_size_read(inode))
+ if (off >= i_size) {
*retry_op = CHECK_EOF;
- ret = off - iocb->ki_pos;
- iocb->ki_pos = off;
+ ret = i_size - iocb->ki_pos;
+ iocb->ki_pos = i_size;
+ } else {
+ ret = off - iocb->ki_pos;
+ iocb->ki_pos = off;
+ }
}
dout("sync_read result %zd retry_op %d\n", ret, *retry_op);