Commit 1209bbdf authored Oct 02, 2014 by Pavel Shilovsky Committed by Steve French Oct 02, 2014

CIFS: Fix readpages retrying on reconnects



If we got a reconnect error from async readv we re-add pages back
to page_list and continue loop. That is wrong because these pages
have been already added to the pagecache but page_list has pages that
have not been added to the pagecache yet. This ends up with a general
protection fault in put_pages after readpages. Fix it by not retrying
the read of these pages and falling back to readpage instead.

Fixes debian bug 762306

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
Tested-by: Arthur Marsh <arthur.marsh@internode.on.net>

parent 19e81573

fs/cifs/file.c

+1 −7

Original line number	Diff line number	Diff line
		@@ -3568,15 +3568,9 @@ static int cifs_readpages(struct file file, struct address_space mapping,
		lru_cache_add_file(page);
		unlock_page(page);
		page_cache_release(page);
		if (rc == -EAGAIN)
		list_add_tail(&page->lru, &tmplist);
		}
		/* Fallback to the readpage in error/reconnect cases */
		kref_put(&rdata->refcount, cifs_readdata_release);
		if (rc == -EAGAIN) {
		/* Re-add pages to the page_list and retry */
		list_splice(&tmplist, page_list);
		continue;
		}
		break;
		}

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