Commit fe683ada authored by Dan Williams's avatar Dan Williams Committed by Linus Torvalds
Browse files

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: default avatarDan Williams <dan.j.williams@intel.com>
Reported-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0e749e54

fs/block_dev.c

+2 −0
Original line number Diff line number Diff line
@@ -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);

fs/dax.c

+0 −1
Original line number Diff line number Diff line
@@ -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);

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