Hi David,
Below change needs to be applied on top of your branch.
lxsmbadmin@netfsvm:~/latest_14mar/linux-fs$ git diff
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index af7483c246ac..447934ff80b8 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2969,6 +2969,12 @@ cifs_write_from_iter(loff_t offset, size_t len,
struct iov_iter *from,
cur_len = min_t(const size_t, len, wsize);
+ if (!cur_len) {
+ rc = -EAGAIN;
+ add_credits_and_wake_if(server, credits, 0);
+ break;
+ }
+
wdata = cifs_writedata_alloc(cifs_uncached_writev_complete);
if (!wdata) {
rc = -ENOMEM;
lxsmbadmin@netfsvm:~/xfstests-dev$ sudo ./check generic/013
SECTION -- smb3
FSTYP -- cifs
PLATFORM -- Linux/x86_64 netfsvm 5.17.0-rc6+ #1 SMP PREEMPT Mon
Mar 14 09:05:47 UTC 2022
MKFS_OPTIONS -- //127.0.0.1/sambashare_scratch
MOUNT_OPTIONS -- -ousername=,password=,noperm,vers=3.0,actimeo=0
//127.0.0.1/sambashare_scratch /mnt/xfstests_scratch
generic/013 149s
Ran: generic/013
Passed all 1 tests
SECTION -- smb3
=========================
Ran: generic/013
Passed all 1 tests
Regards,
Rohith
On Fri, Mar 11, 2022 at 1:56 PM David Howells <dhowells@xxxxxxxxxx> wrote:
>
>
> David Howells <dhowells@xxxxxxxxxx> wrote:
>
> > The other issue is that if I run splice to an empty file, it works; running
> > another splice to the same file will result in the server giving
> > STATUS_ACCESS_DENIED when cifs_write_begin() tries to read from the file:
> >
> > 7 0.009485249 192.168.6.2 → 192.168.6.1 SMB2 183 Read Request Len:65536 Off:0 File: x
> > 8 0.009674245 192.168.6.1 → 192.168.6.2 SMB2 143 Read Response, Error: STATUS_ACCESS_DENIED
> >
> > Actually - that might be because the file is only 65536 bytes long because the
> > first splice finished short.
>
> Actually, it's because I opened the output file O_WRONLY. If I open it
> O_RDWR, it works. The test program is attached below.
>
> David
> ---
> #define _GNU_SOURCE
> #include <stdio.h>
> #include <stdlib.h>
> #include <string.h>
> #include <unistd.h>
> #include <fcntl.h>
>
> int main(int argc, char *argv[])
> {
> off64_t opos;
> size_t len;
> int in, out;
>
> if (argc != 4) {
> printf("Format: %s size in out\n", argv[0]);
> exit(2);
> }
>
> len = atol(argv[1]);
>
> if (strcmp(argv[2], "-") != 0) {
> in = open(argv[2], O_RDONLY);
> if (in < 0) {
> perror(argv[2]);
> return 1;
> }
> } else {
> in = 0;
> }
>
> if (strcmp(argv[3], "-") != 0) {
> out = open(argv[3], O_WRONLY); // Change to O_RDWR
> if (out < 0) {
> perror(argv[3]);
> return 1;
> }
> } else {
> out = 1;
> }
>
> opos = 3;
> if (splice(in, NULL, out, &opos, len, 0) < 0) {
> perror("splice");
> return 1;
> }
>
> if (close(in) < 0) {
> perror("close/in");
> return 1;
> }
>
> if (close(out) < 0) {
> perror("close/out");
> return 1;
> }
>
> return 0;
> }
>
