cifs: revalidate mapping prior to satisfying read_iter request with cache=loose
Before satisfying a read with cache=loose, we should always check
that the pagecache is valid before allowing a read to be satisfied
out of it.
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: Steve French <smfrench@gmail.com>
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 2c90d07..8883980 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -725,6 +725,19 @@
goto out;
}
+static ssize_t
+cifs_loose_read_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+ ssize_t rc;
+ struct inode *inode = file_inode(iocb->ki_filp);
+
+ rc = cifs_revalidate_mapping(inode);
+ if (rc)
+ return rc;
+
+ return generic_file_read_iter(iocb, iter);
+}
+
static ssize_t cifs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct inode *inode = file_inode(iocb->ki_filp);
@@ -881,7 +894,7 @@
const struct file_operations cifs_file_ops = {
.read = new_sync_read,
.write = new_sync_write,
- .read_iter = generic_file_read_iter,
+ .read_iter = cifs_loose_read_iter,
.write_iter = cifs_file_write_iter,
.open = cifs_open,
.release = cifs_close,
@@ -939,7 +952,7 @@
const struct file_operations cifs_file_nobrl_ops = {
.read = new_sync_read,
.write = new_sync_write,
- .read_iter = generic_file_read_iter,
+ .read_iter = cifs_loose_read_iter,
.write_iter = cifs_file_write_iter,
.open = cifs_open,
.release = cifs_close,