return (error);
}
-static struct page **
-pages_vector_from_list(struct list_head *pages, unsigned nr_pages)
-{
- struct page **pl;
- struct page *t;
- unsigned page_idx;
-
- pl = kmalloc(sizeof(*pl) * nr_pages, GFP_NOFS);
- if (!pl)
- return ERR_PTR(-ENOMEM);
-
- page_idx = 0;
- list_for_each_entry_reverse(t, pages, lru) {
- pl[page_idx] = t;
- page_idx++;
- }
-
- return pl;
-}
-
-static int
-zpl_readpages(struct file *file, struct address_space *mapping,
- struct list_head *pages, unsigned nr_pages)
-{
- struct inode *ip;
- struct page **pl;
- struct page *p, *n;
- int error;
-
- ip = mapping->host;
-
- pl = pages_vector_from_list(pages, nr_pages);
- if (IS_ERR(pl))
- return PTR_ERR(pl);
-
- error = -zfs_getpage(ip, pl, nr_pages);
- if (error)
- goto error;
-
- list_for_each_entry_safe_reverse(p, n, pages, lru) {
-
- list_del(&p->lru);
-
- flush_dcache_page(p);
- SetPageUptodate(p);
- unlock_page(p);
- page_cache_release(p);
- }
-
-error:
- kfree(pl);
- return error;
-}
-
/*
* Populate a page with data for the Linux page cache. This function is
* only used to support mmap(2). There will be an identical copy of the
return error;
}
+/*
+ * Populate a set of pages with data for the Linux page cache. This
+ * function will only be called for read ahead and never for demand
+ * paging. For simplicity, the code relies on read_cache_pages() to
+ * correctly lock each page for IO and call zpl_readpage().
+ */
+static int
+zpl_readpages(struct file *filp, struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages)
+{
+ return (read_cache_pages(mapping, pages,
+ (filler_t *)zpl_readpage, filp));
+}
+
int
zpl_putpage(struct page *pp, struct writeback_control *wbc, void *data)
{
- int error;
-
- error = -zfs_putpage(pp, wbc, data);
+ struct address_space *mapping = data;
- if (error) {
- SetPageError(pp);
- ClearPageUptodate(pp);
- } else {
- ClearPageError(pp);
- SetPageUptodate(pp);
- flush_dcache_page(pp);
- }
-
- unlock_page(pp);
- return error;
+ ASSERT(PageLocked(pp));
+ ASSERT(!PageWriteback(pp));
+
+ /*
+ * Disable the normal reclaim path for zpl_putpage(). This
+ * ensures that all memory allocations under this call path
+ * will never enter direct reclaim. If this were to happen
+ * the VM might try to write out additional pages by calling
+ * zpl_putpage() again resulting in a deadlock.
+ */
+ current->flags |= PF_MEMALLOC;
+ (void) zfs_putpage(mapping->host, pp, wbc);
+ current->flags &= ~PF_MEMALLOC;
+
+ return (0);
}
static int