CIFS: Separate filling pages from 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 ff4a9c3..f96f61c 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2423,11 +2423,53 @@
return rc;
}
+static int
+wdata_fill_from_iovec(struct cifs_writedata *wdata, struct iov_iter *from,
+ size_t *len, unsigned long *num_pages)
+{
+ size_t save_len, copied, bytes, cur_len = *len;
+ unsigned long i, nr_pages = *num_pages;
+
+ save_len = cur_len;
+ for (i = 0; i < nr_pages; i++) {
+ bytes = min_t(const size_t, cur_len, PAGE_SIZE);
+ copied = copy_page_from_iter(wdata->pages[i], 0, bytes, from);
+ cur_len -= copied;
+ /*
+ * If we didn't copy as much as we expected, then that
+ * may mean we trod into an unmapped area. Stop copying
+ * at that point. On the next pass through the big
+ * loop, we'll likely end up getting a zero-length
+ * write and bailing out of it.
+ */
+ if (copied < bytes)
+ break;
+ }
+ cur_len = save_len - cur_len;
+ *len = cur_len;
+
+ /*
+ * If we have no data to send, then that probably means that
+ * the copy above failed altogether. That's most likely because
+ * the address in the iovec was bogus. Return -EFAULT and let
+ * the caller free anything we allocated and bail out.
+ */
+ if (!cur_len)
+ return -EFAULT;
+
+ /*
+ * i + 1 now represents the number of pages we actually used in
+ * the copy phase above.
+ */
+ *num_pages = i + 1;
+ return 0;
+}
+
static ssize_t
cifs_iovec_write(struct file *file, struct iov_iter *from, loff_t *poffset)
{
- unsigned long nr_pages, i;
- size_t bytes, copied, len, cur_len;
+ unsigned long nr_pages, num_pages, i;
+ size_t len, cur_len;
ssize_t total_written = 0;
loff_t offset;
struct cifsFileInfo *open_file;
@@ -2464,8 +2506,6 @@
pid = current->tgid;
do {
- size_t save_len;
-
nr_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
wdata = cifs_writedata_alloc(nr_pages,
cifs_uncached_writev_complete);
@@ -2480,44 +2520,20 @@
break;
}
- save_len = cur_len;
- for (i = 0; i < nr_pages; i++) {
- bytes = min_t(size_t, cur_len, PAGE_SIZE);
- copied = copy_page_from_iter(wdata->pages[i], 0, bytes,
- from);
- cur_len -= copied;
- /*
- * If we didn't copy as much as we expected, then that
- * may mean we trod into an unmapped area. Stop copying
- * at that point. On the next pass through the big
- * loop, we'll likely end up getting a zero-length
- * write and bailing out of it.
- */
- if (copied < bytes)
- break;
- }
- cur_len = save_len - cur_len;
-
- /*
- * If we have no data to send, then that probably means that
- * the copy above failed altogether. That's most likely because
- * the address in the iovec was bogus. Set the rc to -EFAULT,
- * free anything we allocated and bail out.
- */
- if (!cur_len) {
+ num_pages = nr_pages;
+ rc = wdata_fill_from_iovec(wdata, from, &cur_len, &num_pages);
+ if (rc) {
for (i = 0; i < nr_pages; i++)
put_page(wdata->pages[i]);
kfree(wdata);
- rc = -EFAULT;
break;
}
/*
- * i + 1 now represents the number of pages we actually used in
- * the copy phase above. Bring nr_pages down to that, and free
- * any pages that we didn't use.
+ * Bring nr_pages down to the number of pages we actually used,
+ * and free any pages that we didn't use.
*/
- for ( ; nr_pages > i + 1; nr_pages--)
+ for ( ; nr_pages > num_pages; nr_pages--)
put_page(wdata->pages[nr_pages - 1]);
wdata->sync_mode = WB_SYNC_ALL;