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 <ross.zwisler@xxxxxxxxxxxxxxx> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> --- 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 fe0cc27929ec..6a0fc382e7af 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 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); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>