Commit e374d90f authored by Pavel Shilovsky's avatar Pavel Shilovsky Committed by Steve French
Browse files

CIFS: Fix rsize usage for sync read 



If a server changes maximum buffer size for read requests (rsize)
on reconnect we can fail on repeating with a big size buffer on
-EAGAIN error in cifs_read. Fix this by checking rsize all the
time before repeating requests.

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 25f40259

fs/cifs/file.c

+14 −12
Original line number Diff line number Diff line
@@ -3148,18 +3148,19 @@ cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset) 


	for (total_read = 0, cur_offset = read_data; read_size > total_read;

	     total_read += bytes_read, cur_offset += bytes_read) {

		current_read_size = min_t(uint, read_size - total_read, rsize);

		do {

			current_read_size = min_t(uint, read_size - total_read,

						  rsize);

			/*

		 * For windows me and 9x we do not want to request more than it

		 * negotiated since it will refuse the read then.

			 * For windows me and 9x we do not want to request more

			 * than it negotiated since it will refuse the read

			 * then.

			 */

			if ((tcon->ses) && !(tcon->ses->capabilities &

				tcon->ses->server->vals->cap_large_files)) {

			current_read_size = min_t(uint, current_read_size,

					CIFSMaxBufSize);

				current_read_size = min_t(uint,

					current_read_size, CIFSMaxBufSize);

			}

		rc = -EAGAIN;

		while (rc == -EAGAIN) {

			if (open_file->invalidHandle) {

				rc = cifs_reopen_file(open_file, true);

				if (rc != 0)
@@ -3172,7 +3173,8 @@ cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset) 
			rc = server->ops->sync_read(xid, open_file, &io_parms,

						    &bytes_read, &cur_offset,

						    &buf_type);

		}

		} while (rc == -EAGAIN);



		if (rc || (bytes_read == 0)) {

			if (total_read) {

				break;