From fe683adabfe6629c0b6db32bbbc1ce6cacbf2117 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 15 Jan 2016 16:55:56 -0800 Subject: [PATCH] dax: guarantee page aligned results from bdev_direct_access() 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. Signed-off-by: Dan Williams Reported-by: Ross Zwisler Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 81c0705558be..ddc6cdd1860b 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -494,6 +494,8 @@ 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 11721c0fc127..1080fb50fa4d 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_128K); clear_pmem(addr, sz); size -= sz; - BUG_ON(sz & 511); sector += sz / 512; cond_resched(); } while (size); -- 2.20.1