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>
This commit is contained in:
Pavel Shilovsky 2014-10-02 20:13:35 +04:00 коммит произвёл Steve French
Родитель 19e81573fc
Коммит 1209bbdff2
1 изменённых файлов: 1 добавлений и 7 удалений

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@ -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;
}