* If task is NULL, the page copy occurs syncronously, and the routine
* returns with page still locked. If task is non-NULL, then page copies
* may occur in the background, and the page will be unlocked when it is
- * ready for use.
+ * ready for use. Note that if task is non-NULL and we encounter an error
+ * before we start the background copy, we MUST unlock 'page' before we return.
*/
static int
afs_linux_read_cache(struct file *cachefp, struct page *page,
if (!PageUptodate(cachepage)) {
ClearPageError(cachepage);
- code = cachemapping->a_ops->readpage(NULL, cachepage);
+ /* Note that ->readpage always handles unlocking the given page, even
+ * when an error is returned. */
+ code = cachemapping->a_ops->readpage(NULL, cachepage);
if (!code && !task) {
wait_on_page_locked(cachepage);
}
}
}
+ out:
if (code && task) {
unlock_page(page);
}
-out:
if (cachepage)
put_page(cachepage);
if (!pagevec_add(&lrupv, page))
__pagevec_lru_add_file(&lrupv);
+ /* Note that add_to_page_cache() locked 'page'.
+ * afs_linux_read_cache() is guaranteed to handle unlocking it. */
afs_linux_read_cache(cacheFp, page, tdc->f.chunk, &lrupv, task);
}
put_page(page);