[PATCH 4.20 129/145] CIFS: return correct errors when pinning memory failed for direct I/O

From: Greg Kroah-Hartman
Date: Mon Jan 07 2019 - 07:46:15 EST


4.20-stable review patch. If anyone has any objections, please let me know.

------------------

From: Long Li <longli@xxxxxxxxxxxxx>

commit 54e94ff94eac887ddb59cfd46b18896da5695e35 upstream.

When pinning memory failed, we should return the correct error code and
rewind the SMB credits.

Reported-by: Murphy Zhou <jencce.kernel@xxxxxxxxx>
Signed-off-by: Long Li <longli@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Cc: Murphy Zhou <jencce.kernel@xxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/cifs/file.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2630,6 +2630,9 @@ cifs_write_from_iter(loff_t offset, size
result, from->type,
from->iov_offset, from->count);
dump_stack();
+
+ rc = result;
+ add_credits_and_wake_if(server, credits, 0);
break;
}
cur_len = (size_t)result;
@@ -3313,13 +3316,16 @@ cifs_send_async_read(loff_t offset, size
cur_len, &start);
if (result < 0) {
cifs_dbg(VFS,
- "couldn't get user pages (cur_len=%zd)"
+ "couldn't get user pages (rc=%zd)"
" iter type %d"
" iov_offset %zd count %zd\n",
result, direct_iov.type,
direct_iov.iov_offset,
direct_iov.count);
dump_stack();
+
+ rc = result;
+ add_credits_and_wake_if(server, credits, 0);
break;
}
cur_len = (size_t)result;