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Commit 25f40259 authored by Pavel Shilovsky's avatar Pavel Shilovsky Committed by Steve French
Browse files

CIFS: Fix rsize usage in user read 



If a server changes maximum buffer size for read (rsize) requests
on reconnect we can fail on repeating with a big size buffer on
-EAGAIN error in user 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 0ada36b2

fs/cifs/file.c

+22 −23
Original line number Diff line number Diff line
@@ -2828,26 +2828,6 @@ cifs_uncached_readdata_release(struct kref *refcount) 
	cifs_readdata_release(refcount);

}



static int

cifs_retry_async_readv(struct cifs_readdata *rdata)

{

	int rc;

	struct TCP_Server_Info *server;



	server = tlink_tcon(rdata->cfile->tlink)->ses->server;



	do {

		if (rdata->cfile->invalidHandle) {

			rc = cifs_reopen_file(rdata->cfile, true);

			if (rc != 0)

				continue;

		}

		rc = server->ops->async_readv(rdata);

	} while (rc == -EAGAIN);



	return rc;

}



/**

 * cifs_readdata_to_iov - copy data from pages in response to an iovec

 * @rdata:	the readdata response with list of pages holding data
@@ -2941,6 +2921,9 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file, 
	size_t cur_len;

	int rc;

	pid_t pid;

	struct TCP_Server_Info *server;



	server = tlink_tcon(open_file->tlink)->ses->server;



	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)

		pid = open_file->pid;
@@ -2971,11 +2954,15 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file, 
		rdata->pagesz = PAGE_SIZE;

		rdata->read_into_pages = cifs_uncached_read_into_pages;



		rc = cifs_retry_async_readv(rdata);

		if (!rdata->cfile->invalidHandle ||

		    !cifs_reopen_file(rdata->cfile, true))

			rc = server->ops->async_readv(rdata);

error:

		if (rc) {

			kref_put(&rdata->refcount,

				 cifs_uncached_readdata_release);

			if (rc == -EAGAIN)

				continue;

			break;

		}
@@ -3023,8 +3010,8 @@ ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to) 


	len = iov_iter_count(to);

	/* the loop below should proceed in the order of increasing offsets */

	list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {

again:

	list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {

		if (!rc) {

			/* FIXME: freezable sleep too? */

			rc = wait_for_completion_killable(&rdata->done);
@@ -3034,7 +3021,19 @@ ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to) 
				rc = rdata->result;

				/* resend call if it's a retryable error */

				if (rc == -EAGAIN) {

					rc = cifs_retry_async_readv(rdata);

					struct list_head tmp_list;



					list_del_init(&rdata->list);

					INIT_LIST_HEAD(&tmp_list);



					rc = cifs_send_async_read(rdata->offset,

						rdata->bytes, rdata->cfile,

						cifs_sb, &tmp_list);



					list_splice(&tmp_list, &rdata_list);



					kref_put(&rdata->refcount,

						cifs_uncached_readdata_release);

					goto again;

				}

			} else {