From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f178.google.com (mail-pf0-f178.google.com [209.85.192.178]) by kanga.kvack.org (Postfix) with ESMTP id 5D7A46B027D for ; Mon, 7 Dec 2015 20:33:20 -0500 (EST) Received: by pfbg73 with SMTP id g73so3171960pfb.1 for ; Mon, 07 Dec 2015 17:33:20 -0800 (PST) Received: from mga11.intel.com (mga11.intel.com. [192.55.52.93]) by mx.google.com with ESMTP id t72si1283148pfa.153.2015.12.07.17.33.19 for ; Mon, 07 Dec 2015 17:33:19 -0800 (PST) Subject: [PATCH -mm 03/25] dax: guarantee page aligned results from bdev_direct_access() From: Dan Williams Date: Mon, 07 Dec 2015 17:32:52 -0800 Message-ID: <20151208013252.25030.89320.stgit@dwillia2-desk3.jf.intel.com> In-Reply-To: <20151208013236.25030.68781.stgit@dwillia2-desk3.jf.intel.com> References: <20151208013236.25030.68781.stgit@dwillia2-desk3.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, Ross Zwisler , linux-nvdimm@lists.01.org If a ->direct_access() implementation ever returns a map count less than PAGE_SIZE, catch the error in bdev_direct_access(). This simplifies error checking in upper layers. Reported-by: Ross Zwisler Signed-off-by: Dan Williams --- fs/block_dev.c | 2 ++ fs/dax.c | 1 - 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index c27362de0039..653d14ccc86e 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -489,6 +489,8 @@ long bdev_direct_access(struct block_device *bdev, sector_t sector, avail = ops->direct_access(bdev, sector, addr, pfn); if (!avail) return -ERANGE; + if (avail > 0 && avail & ~PAGE_MASK) + return -ENXIO; return min(avail, size); } EXPORT_SYMBOL_GPL(bdev_direct_access); diff --git a/fs/dax.c b/fs/dax.c index e11d88835bb2..6e498c2570bf 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -52,7 +52,6 @@ int dax_clear_blocks(struct inode *inode, sector_t block, long size) sz = min_t(long, count, SZ_1M); clear_pmem(addr, sz); size -= sz; - BUG_ON(sz & 511); sector += sz / 512; cond_resched(); } while (size); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org