block: implement blkdev_readpages
Doing a proper block dev ->readpages() speeds up the crazy dump(8)
approach of using interleaved process IO.
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fs/block_dev.c b/fs/block_dev.c
index f45dbc1..a85fe31 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -331,6 +331,12 @@
return block_read_full_page(page, blkdev_get_block);
}
+static int blkdev_readpages(struct file *file, struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages)
+{
+ return mpage_readpages(mapping, pages, nr_pages, blkdev_get_block);
+}
+
static int blkdev_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
@@ -1399,6 +1405,7 @@
static const struct address_space_operations def_blk_aops = {
.readpage = blkdev_readpage,
+ .readpages = blkdev_readpages,
.writepage = blkdev_writepage,
.sync_page = block_sync_page,
.write_begin = blkdev_write_begin,