The return value of copy_to_iter() function will never be negative,
it is the number of bytes copied, or zero if nothing was copied.
Update the check to treat 0 as an error, and return -1 in that case.
Fixes: d08089f649a0 ("cifs: Change the I/O paths to use an iterator rather than a page list")
Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>
---
fs/smb/client/smb2ops.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index 058050f744c0..ac8a5bd6aec4 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -4650,7 +4650,7 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
unsigned int pad_len;
struct cifs_io_subrequest *rdata = mid->callback_data;
struct smb2_hdr *shdr = (struct smb2_hdr *)buf;
- int length;
+ size_t copied;
bool use_rdma_mr = false;
if (shdr->Command != SMB2_READ) {
@@ -4763,10 +4763,10 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
} else if (buf_len >= data_offset + data_len) {
/* read response payload is in buf */
WARN_ONCE(buffer, "read data can be either in buf or in buffer");
- length = copy_to_iter(buf + data_offset, data_len, &rdata->subreq.io_iter);
- if (length < 0)
- return length;
- rdata->got_bytes = data_len;
+ copied = copy_to_iter(buf + data_offset, data_len, &rdata->subreq.io_iter);
+ if (copied == 0)
+ return -1;
+ rdata->got_bytes = copied;
} else {
/* read response payload cannot be in both buf and pages */
WARN_ONCE(1, "buf can not contain only a part of read data");
--
2.36.1