From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Darrick J. Wong" Subject: [PATCH 1/3] block: invalidate the page cache when issuing BLKZEROOUT. Date: Fri, 04 Mar 2016 16:56:03 -0800 Message-ID: <20160305005603.29738.58460.stgit@birch.djwong.org> References: <20160305005556.29738.66782.stgit@birch.djwong.org> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160305005556.29738.66782.stgit-PTl6brltDGh4DFYR7WNSRA@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org, torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, darrick.wong-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org Cc: hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, tytso-3s7WtUTddSA@public.gmane.org, martin.petersen-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, david-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, shane.seymour-ZPxbGqLxI0U@public.gmane.org, bfields-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, jlayton-vpEMnDpepFuMZCB2o+C8xQ@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org List-Id: linux-api@vger.kernel.org Invalidate the page cache (as a regular O_DIRECT write would do) to avoid returning stale cache contents at a later time. v5: Refactor the 4.4 refactoring of the ioctl code into separate functions. Split the page invalidation and the new ioctl into separate patches. Signed-off-by: Darrick J. Wong --- block/ioctl.c | 29 +++++++++++++++++++++++------ 1 file changed, 23 insertions(+), 6 deletions(-) diff --git a/block/ioctl.c b/block/ioctl.c index d8996bb..c6eb462 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -226,7 +226,9 @@ static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode, unsigned long arg) { uint64_t range[2]; - uint64_t start, len; + struct address_space *mapping; + uint64_t start, end, len; + int ret; if (!(mode & FMODE_WRITE)) return -EBADF; @@ -236,18 +238,33 @@ static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode, start = range[0]; len = range[1]; + end = start + len - 1; if (start & 511) return -EINVAL; if (len & 511) return -EINVAL; - start >>= 9; - len >>= 9; - - if (start + len > (i_size_read(bdev->bd_inode) >> 9)) + if (end >= (uint64_t)i_size_read(bdev->bd_inode)) + return -EINVAL; + if (end < start) return -EINVAL; - return blkdev_issue_zeroout(bdev, start, len, GFP_KERNEL, false); + /* Invalidate the page cache, including dirty pages */ + mapping = bdev->bd_inode->i_mapping; + truncate_inode_pages_range(mapping, start, end); + + ret = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL, + false); + if (ret) + return ret; + + /* + * Invalidate again; if someone wandered in and dirtied a page, + * the caller will be given -EBUSY. + */ + return invalidate_inode_pages2_range(mapping, + start >> PAGE_CACHE_SHIFT, + end >> PAGE_CACHE_SHIFT); } static int put_ushort(unsigned long arg, unsigned short val)