Commit 6ec0b01b authored by Pavel Shilovsky's avatar Pavel Shilovsky Committed by Steve French
Browse files

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: default avatarShirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: default avatarPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
parent 43de94ea

fs/cifs/cifssmb.c

+0 −4
Original line number Diff line number Diff line
@@ -196,10 +196,6 @@ cifs_reconnect_tcon(struct cifs_tcon *tcon, int smb_command) 
	if (rc)

		goto out;



	/*

	 * FIXME: check if wsize needs updated due to negotiated smb buffer

	 * 	  size shrinking

	 */

	atomic_inc(&tconInfoReconnectCount);



	/* tell server Unix caps we support */

fs/cifs/file.c

+39 −24
Original line number Diff line number Diff line
@@ -2401,28 +2401,6 @@ cifs_uncached_writev_complete(struct work_struct *work) 
	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 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, 
	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 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, 
		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 @@ cifs_iovec_write(struct file *file, struct iov_iter *from, loff_t *poffset) 
	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 @@ cifs_iovec_write(struct file *file, struct iov_iter *from, loff_t *poffset) 
	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 @@ restart_loop: 


			/* 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;

			}

		}

fs/cifs/smb2pdu.c

+0 −4
Original line number Diff line number Diff line
@@ -245,10 +245,6 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon) 
	if (rc)

		goto out;

	atomic_inc(&tconInfoReconnectCount);

	/*

	 * BB FIXME add code to check if wsize needs update due to negotiated

	 * smb buffer size shrinking.

	 */

out:

	/*

	 * Check if handle based operation so we know whether we can continue

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