CIFS: Fix wsize usage in iovec write
If a server change maximum buffer size for write (wsize) requests
on reconnect we can fail on repeating with a big size buffer on
-EAGAIN error in iovec write. Fix this by checking wsize all the
time before repeating request in iovec write.
Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 6660698..c9c4f5a 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2401,28 +2401,6 @@
kref_put(&wdata->refcount, cifs_uncached_writedata_release);
}
-/* attempt to send write to server, retry on any -EAGAIN errors */
-static int
-cifs_uncached_retry_writev(struct cifs_writedata *wdata)
-{
- int rc;
- struct TCP_Server_Info *server;
-
- server = tlink_tcon(wdata->cfile->tlink)->ses->server;
-
- do {
- if (wdata->cfile->invalidHandle) {
- rc = cifs_reopen_file(wdata->cfile, false);
- if (rc != 0)
- continue;
- }
- rc = server->ops->async_writev(wdata,
- cifs_uncached_writedata_release);
- } while (rc == -EAGAIN);
-
- return rc;
-}
-
static int
wdata_fill_from_iovec(struct cifs_writedata *wdata, struct iov_iter *from,
size_t *len, unsigned long *num_pages)
@@ -2474,13 +2452,19 @@
size_t cur_len;
unsigned long nr_pages, num_pages, i;
struct cifs_writedata *wdata;
+ struct iov_iter saved_from;
+ loff_t saved_offset = offset;
pid_t pid;
+ struct TCP_Server_Info *server;
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
pid = open_file->pid;
else
pid = current->tgid;
+ server = tlink_tcon(open_file->tlink)->ses->server;
+ memcpy(&saved_from, from, sizeof(struct iov_iter));
+
do {
nr_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
wdata = cifs_writedata_alloc(nr_pages,
@@ -2520,10 +2504,20 @@
wdata->bytes = cur_len;
wdata->pagesz = PAGE_SIZE;
wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
- rc = cifs_uncached_retry_writev(wdata);
+
+ if (!wdata->cfile->invalidHandle ||
+ !cifs_reopen_file(wdata->cfile, false))
+ rc = server->ops->async_writev(wdata,
+ cifs_uncached_writedata_release);
if (rc) {
kref_put(&wdata->refcount,
cifs_uncached_writedata_release);
+ if (rc == -EAGAIN) {
+ memcpy(from, &saved_from,
+ sizeof(struct iov_iter));
+ iov_iter_advance(from, offset - saved_offset);
+ continue;
+ }
break;
}
@@ -2545,6 +2539,7 @@
struct cifs_sb_info *cifs_sb;
struct cifs_writedata *wdata, *tmp;
struct list_head wdata_list;
+ struct iov_iter saved_from;
int rc;
len = iov_iter_count(from);
@@ -2565,6 +2560,8 @@
if (!tcon->ses->server->ops->async_writev)
return -ENOSYS;
+ memcpy(&saved_from, from, sizeof(struct iov_iter));
+
rc = cifs_write_from_iter(*poffset, len, from, open_file, cifs_sb,
&wdata_list);
@@ -2596,7 +2593,25 @@
/* resend call if it's a retryable error */
if (rc == -EAGAIN) {
- rc = cifs_uncached_retry_writev(wdata);
+ struct list_head tmp_list;
+ struct iov_iter tmp_from;
+
+ INIT_LIST_HEAD(&tmp_list);
+ list_del_init(&wdata->list);
+
+ memcpy(&tmp_from, &saved_from,
+ sizeof(struct iov_iter));
+ iov_iter_advance(&tmp_from,
+ wdata->offset - *poffset);
+
+ rc = cifs_write_from_iter(wdata->offset,
+ wdata->bytes, &tmp_from,
+ open_file, cifs_sb, &tmp_list);
+
+ list_splice(&tmp_list, &wdata_list);
+
+ kref_put(&wdata->refcount,
+ cifs_uncached_writedata_release);
goto restart_loop;
}
}