From: Ross Zwisler Subject: [PATCH v9 02/16] dax: remove buffer_size_valid() Date: Tue, 1 Nov 2016 13:54:04 -0600 Message-ID: <1478030058-1422-3-git-send-email-ross.zwisler@linux.intel.com> References: <1478030058-1422-1-git-send-email-ross.zwisler@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Theodore Ts'o , Matthew Wilcox , Dave Chinner , linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, Christoph Hellwig , linux-xfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Andreas Dilger , Alexander Viro , linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jan Kara , linux-ext4-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Andrew Morton To: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Return-path: In-Reply-To: <1478030058-1422-1-git-send-email-ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" List-Id: linux-ext4.vger.kernel.org Now that ext4 properly sets bh.b_size when we call get_block() for a hole, rely on that value and remove the buffer_size_valid() sanity check. Signed-off-by: Ross Zwisler Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig --- fs/dax.c | 22 +--------------------- 1 file changed, 1 insertion(+), 21 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 014defd..b09817a 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -123,19 +123,6 @@ static bool buffer_written(struct buffer_head *bh) return buffer_mapped(bh) && !buffer_unwritten(bh); } -/* - * When ext4 encounters a hole, it returns without modifying the buffer_head - * which means that we can't trust b_size. To cope with this, we set b_state - * to 0 before calling get_block and, if any bit is set, we know we can trust - * b_size. Unfortunate, really, since ext4 knows precisely how long a hole is - * and would save us time calling get_block repeatedly. - */ -static bool buffer_size_valid(struct buffer_head *bh) -{ - return bh->b_state != 0; -} - - static sector_t to_sector(const struct buffer_head *bh, const struct inode *inode) { @@ -177,8 +164,6 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter, rc = get_block(inode, block, bh, rw == WRITE); if (rc) break; - if (!buffer_size_valid(bh)) - bh->b_size = 1 << blkbits; bh_max = pos - first + bh->b_size; bdev = bh->b_bdev; /* @@ -1012,12 +997,7 @@ int dax_pmd_fault(struct vm_area_struct *vma, unsigned long address, bdev = bh.b_bdev; - /* - * If the filesystem isn't willing to tell us the length of a hole, - * just fall back to PTEs. Calling get_block 512 times in a loop - * would be silly. - */ - if (!buffer_size_valid(&bh) || bh.b_size < PMD_SIZE) { + if (bh.b_size < PMD_SIZE) { dax_pmd_dbg(&bh, address, "allocated block too small"); return VM_FAULT_FALLBACK; } -- 2.7.4