From patchwork Thu Jan 14 19:47:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12020787 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A642C433E6 for ; Thu, 14 Jan 2021 19:48:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 65FFE239E4 for ; Thu, 14 Jan 2021 19:48:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730012AbhANTsK (ORCPT ); Thu, 14 Jan 2021 14:48:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49192 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728474AbhANTsK (ORCPT ); Thu, 14 Jan 2021 14:48:10 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 042FFC061757; Thu, 14 Jan 2021 11:47:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:In-Reply-To:References; bh=3rwfs/Oho7tVoyvf+cQqxjsdm4pscyDI+ONpU9zok9w=; b=b+VVRZJFrCC6ste4nYhpmn5C79 Q5ymK8lce4BnIrmTnsGUJfMS13COVq9j28qO27ZjeNO+fvI6aLOfzI+KVY4SUCizTelAPoHfq6a09 V49ilrTJQey0bi37N7ml7NbSBHPbZkzXWUOBbrNl0f7TkmSWBXiiW67PMiM0ZFLX82IgVOZ3hrBtw T4SiFeROxy3tOGPRdUNkJwpl5HJq4QXhi5yR2/9p0n5RYyY+XyOdETajZ4n34HmmZRzHUYsKmI7Ek hYjMbvKZUHzdM1CnYTKa+yl06ugbD6VgxiNjiV+Zh5kaun9YU2qlwYEs48FuNqHBMDd0/BkhaOC9z n0CuucHQ==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1l08aK-007zqg-KX; Thu, 14 Jan 2021 19:47:12 +0000 From: "Matthew Wilcox (Oracle)" To: linux-block@vger.kernel.org, 'Jens Axboe ' , Christoph Hellwig , linux-fsdevel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" Subject: [PATCH] block: Add bio_limit Date: Thu, 14 Jan 2021 19:47:06 +0000 Message-Id: <20210114194706.1905866-1-willy@infradead.org> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org It's often inconvenient to use BIO_MAX_PAGES due to min() requiring the sign to be the same. Introduce bio_limit() and change BIO_MAX_PAGES to be unsigned to make it easier for the users. Signed-off-by: Matthew Wilcox (Oracle) --- block/blk-map.c | 4 +--- drivers/block/xen-blkback/blkback.c | 4 +--- drivers/md/dm-io.c | 4 ++-- drivers/md/dm-log-writes.c | 10 +++++----- drivers/nvme/target/io-cmd-bdev.c | 8 ++++---- drivers/nvme/target/passthru.c | 4 ++-- drivers/target/target_core_iblock.c | 9 +++------ drivers/target/target_core_pscsi.c | 2 +- fs/block_dev.c | 10 +++++----- fs/direct-io.c | 2 +- fs/erofs/data.c | 4 +--- fs/ext4/readpage.c | 3 +-- fs/f2fs/data.c | 3 +-- fs/f2fs/node.c | 2 +- fs/iomap/buffered-io.c | 4 ++-- fs/mpage.c | 4 +--- fs/nfs/blocklayout/blocklayout.c | 6 +++--- fs/xfs/xfs_bio_io.c | 2 +- fs/xfs/xfs_buf.c | 4 ++-- include/linux/bio.h | 7 ++++++- 20 files changed, 44 insertions(+), 52 deletions(-) diff --git a/block/blk-map.c b/block/blk-map.c index 21630dccac62..93a7494f4c5a 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -150,9 +150,7 @@ static int bio_copy_user_iov(struct request *rq, struct rq_map_data *map_data, bmd->is_our_pages = !map_data; bmd->is_null_mapped = (map_data && map_data->null_mapped); - nr_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE); - if (nr_pages > BIO_MAX_PAGES) - nr_pages = BIO_MAX_PAGES; + nr_pages = bio_limit(DIV_ROUND_UP(offset + len, PAGE_SIZE)); ret = -ENOMEM; bio = bio_kmalloc(gfp_mask, nr_pages); diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c index 9ebf53903d7b..024fda9b7e3f 100644 --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -1322,9 +1322,7 @@ static int dispatch_rw_block_io(struct xen_blkif_ring *ring, pages[i]->page, seg[i].nsec << 9, seg[i].offset) == 0)) { - - int nr_iovecs = min_t(int, (nseg-i), BIO_MAX_PAGES); - bio = bio_alloc(GFP_KERNEL, nr_iovecs); + bio = bio_alloc(GFP_KERNEL, bio_limit(nseg - i)); if (unlikely(bio == NULL)) goto fail_put_bio; diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c index 4312007d2d34..b52b77447415 100644 --- a/drivers/md/dm-io.c +++ b/drivers/md/dm-io.c @@ -341,8 +341,8 @@ static void do_region(int op, int op_flags, unsigned region, num_bvecs = 1; break; default: - num_bvecs = min_t(int, BIO_MAX_PAGES, - dm_sector_div_up(remaining, (PAGE_SIZE >> SECTOR_SHIFT))); + num_bvecs = bio_limit(dm_sector_div_up(remaining, + (PAGE_SIZE >> SECTOR_SHIFT))); } bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, &io->client->bios); diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c index e3d35c6c9f71..020170798ddf 100644 --- a/drivers/md/dm-log-writes.c +++ b/drivers/md/dm-log-writes.c @@ -264,15 +264,14 @@ static int write_inline_data(struct log_writes_c *lc, void *entry, size_t entrylen, void *data, size_t datalen, sector_t sector) { - int num_pages, bio_pages, pg_datalen, pg_sectorlen, i; + int bio_pages, pg_datalen, pg_sectorlen, i; struct page *page; struct bio *bio; size_t ret; void *ptr; while (datalen) { - num_pages = ALIGN(datalen, PAGE_SIZE) >> PAGE_SHIFT; - bio_pages = min(num_pages, BIO_MAX_PAGES); + bio_pages = bio_limit(ALIGN(datalen, PAGE_SIZE) >> PAGE_SHIFT); atomic_inc(&lc->io_blocks); @@ -364,7 +363,7 @@ static int log_one_block(struct log_writes_c *lc, goto out; atomic_inc(&lc->io_blocks); - bio = bio_alloc(GFP_KERNEL, min(block->vec_cnt, BIO_MAX_PAGES)); + bio = bio_alloc(GFP_KERNEL, bio_limit(block->vec_cnt)); if (!bio) { DMERR("Couldn't alloc log bio"); goto error; @@ -386,7 +385,8 @@ static int log_one_block(struct log_writes_c *lc, if (ret != block->vecs[i].bv_len) { atomic_inc(&lc->io_blocks); submit_bio(bio); - bio = bio_alloc(GFP_KERNEL, min(block->vec_cnt - i, BIO_MAX_PAGES)); + bio = bio_alloc(GFP_KERNEL, + bio_limit(block->vec_cnt - i)); if (!bio) { DMERR("Couldn't alloc log bio"); goto error; diff --git a/drivers/nvme/target/io-cmd-bdev.c b/drivers/nvme/target/io-cmd-bdev.c index 125dde3f410e..d890c0eb5fa0 100644 --- a/drivers/nvme/target/io-cmd-bdev.c +++ b/drivers/nvme/target/io-cmd-bdev.c @@ -185,7 +185,7 @@ static int nvmet_bdev_alloc_bip(struct nvmet_req *req, struct bio *bio, } bip = bio_integrity_alloc(bio, GFP_NOIO, - min_t(unsigned int, req->metadata_sg_cnt, BIO_MAX_PAGES)); + bio_limit(req->metadata_sg_cnt)); if (IS_ERR(bip)) { pr_err("Unable to allocate bio_integrity_payload\n"); return PTR_ERR(bip); @@ -225,7 +225,7 @@ static int nvmet_bdev_alloc_bip(struct nvmet_req *req, struct bio *bio, static void nvmet_bdev_execute_rw(struct nvmet_req *req) { - int sg_cnt = req->sg_cnt; + unsigned int sg_cnt = req->sg_cnt; struct bio *bio; struct scatterlist *sg; struct blk_plug plug; @@ -263,7 +263,7 @@ static void nvmet_bdev_execute_rw(struct nvmet_req *req) bio = &req->b.inline_bio; bio_init(bio, req->inline_bvec, ARRAY_SIZE(req->inline_bvec)); } else { - bio = bio_alloc(GFP_KERNEL, min(sg_cnt, BIO_MAX_PAGES)); + bio = bio_alloc(GFP_KERNEL, bio_limit(sg_cnt)); } bio_set_dev(bio, req->ns->bdev); bio->bi_iter.bi_sector = sector; @@ -290,7 +290,7 @@ static void nvmet_bdev_execute_rw(struct nvmet_req *req) } } - bio = bio_alloc(GFP_KERNEL, min(sg_cnt, BIO_MAX_PAGES)); + bio = bio_alloc(GFP_KERNEL, bio_limit(sg_cnt)); bio_set_dev(bio, req->ns->bdev); bio->bi_iter.bi_sector = sector; bio->bi_opf = op; diff --git a/drivers/nvme/target/passthru.c b/drivers/nvme/target/passthru.c index b9776fc8f08f..ead143edc3cc 100644 --- a/drivers/nvme/target/passthru.c +++ b/drivers/nvme/target/passthru.c @@ -26,7 +26,7 @@ static u16 nvmet_passthru_override_id_ctrl(struct nvmet_req *req) struct nvme_ctrl *pctrl = ctrl->subsys->passthru_ctrl; u16 status = NVME_SC_SUCCESS; struct nvme_id_ctrl *id; - int max_hw_sectors; + unsigned int max_hw_sectors; int page_shift; id = kzalloc(sizeof(*id), GFP_KERNEL); @@ -198,7 +198,7 @@ static int nvmet_passthru_map_sg(struct nvmet_req *req, struct request *rq) bio = &req->p.inline_bio; bio_init(bio, req->inline_bvec, ARRAY_SIZE(req->inline_bvec)); } else { - bio = bio_alloc(GFP_KERNEL, min(req->sg_cnt, BIO_MAX_PAGES)); + bio = bio_alloc(GFP_KERNEL, bio_limit(req->sg_cnt)); bio->bi_end_io = bio_put; } bio->bi_opf = req_op(rq); diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c index 8ed93fd205c7..522a132bd8da 100644 --- a/drivers/target/target_core_iblock.c +++ b/drivers/target/target_core_iblock.c @@ -315,10 +315,8 @@ iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num, int op, * Only allocate as many vector entries as the bio code allows us to, * we'll loop later on until we have handled the whole request. */ - if (sg_num > BIO_MAX_PAGES) - sg_num = BIO_MAX_PAGES; - - bio = bio_alloc_bioset(GFP_NOIO, sg_num, &ib_dev->ibd_bio_set); + bio = bio_alloc_bioset(GFP_NOIO, bio_limit(sg_num), + &ib_dev->ibd_bio_set); if (!bio) { pr_err("Unable to allocate memory for bio\n"); return NULL; @@ -638,8 +636,7 @@ iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio, return -ENODEV; } - bip = bio_integrity_alloc(bio, GFP_NOIO, - min_t(unsigned int, cmd->t_prot_nents, BIO_MAX_PAGES)); + bip = bio_integrity_alloc(bio, GFP_NOIO, bio_limit(cmd->t_prot_nents)); if (IS_ERR(bip)) { pr_err("Unable to allocate bio_integrity_payload\n"); return PTR_ERR(bip); diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c index 7994f27e4527..a3d9a10134c4 100644 --- a/drivers/target/target_core_pscsi.c +++ b/drivers/target/target_core_pscsi.c @@ -881,7 +881,7 @@ pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, if (!bio) { new_bio: - nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages); + nr_vecs = bio_limit(nr_pages); nr_pages -= nr_vecs; /* * Calls bio_kmalloc() and sets bio->bi_end_io() diff --git a/fs/block_dev.c b/fs/block_dev.c index dfbdbfa58391..46849e93a60b 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -214,7 +214,7 @@ static void blkdev_bio_end_io_simple(struct bio *bio) static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter, - int nr_pages) + unsigned int nr_pages) { struct file *file = iocb->ki_filp; struct block_device *bdev = I_BDEV(bdev_file_inode(file)); @@ -348,8 +348,8 @@ static void blkdev_bio_end_io(struct bio *bio) } } -static ssize_t -__blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) +static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, + unsigned int nr_pages) { struct file *file = iocb->ki_filp; struct inode *inode = bdev_file_inode(file); @@ -479,7 +479,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) { - int nr_pages; + unsigned int nr_pages; nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES + 1); if (!nr_pages) @@ -487,7 +487,7 @@ blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) if (is_sync_kiocb(iocb) && nr_pages <= BIO_MAX_PAGES) return __blkdev_direct_IO_simple(iocb, iter, nr_pages); - return __blkdev_direct_IO(iocb, iter, min(nr_pages, BIO_MAX_PAGES)); + return __blkdev_direct_IO(iocb, iter, bio_limit(nr_pages)); } static __init int blkdev_init(void) diff --git a/fs/direct-io.c b/fs/direct-io.c index 1b564c17db29..ac039a968593 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -693,7 +693,7 @@ static inline int dio_new_bio(struct dio *dio, struct dio_submit *sdio, if (ret) goto out; sector = start_sector << (sdio->blkbits - 9); - nr_pages = min(sdio->pages_in_io, BIO_MAX_PAGES); + nr_pages = bio_limit(sdio->pages_in_io); BUG_ON(nr_pages <= 0); dio_bio_alloc(dio, sdio, map_bh->b_bdev, sector, nr_pages); sdio->boundary = 0; diff --git a/fs/erofs/data.c b/fs/erofs/data.c index ea4f693bee22..6edb2f037e43 100644 --- a/fs/erofs/data.c +++ b/fs/erofs/data.c @@ -215,10 +215,8 @@ static inline struct bio *erofs_read_raw_page(struct bio *bio, /* max # of continuous pages */ if (nblocks > DIV_ROUND_UP(map.m_plen, PAGE_SIZE)) nblocks = DIV_ROUND_UP(map.m_plen, PAGE_SIZE); - if (nblocks > BIO_MAX_PAGES) - nblocks = BIO_MAX_PAGES; - bio = bio_alloc(GFP_NOIO, nblocks); + bio = bio_alloc(GFP_NOIO, bio_limit(nblocks)); bio->bi_end_io = erofs_readendio; bio_set_dev(bio, sb->s_bdev); diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c index f014c5e473a9..bb48e471b27c 100644 --- a/fs/ext4/readpage.c +++ b/fs/ext4/readpage.c @@ -371,8 +371,7 @@ int ext4_mpage_readpages(struct inode *inode, * bio_alloc will _always_ be able to allocate a bio if * __GFP_DIRECT_RECLAIM is set, see bio_alloc_bioset(). */ - bio = bio_alloc(GFP_KERNEL, - min_t(int, nr_pages, BIO_MAX_PAGES)); + bio = bio_alloc(GFP_KERNEL, bio_limit(nr_pages)); fscrypt_set_bio_crypt_ctx(bio, inode, next_block, GFP_KERNEL); ext4_set_bio_post_read_ctx(bio, inode, page->index); diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index c18248d54020..025fb5bbf269 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1003,8 +1003,7 @@ static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr, struct bio_post_read_ctx *ctx; unsigned int post_read_steps = 0; - bio = f2fs_bio_alloc(sbi, min_t(int, nr_pages, BIO_MAX_PAGES), - for_write); + bio = f2fs_bio_alloc(sbi, bio_limit(nr_pages), for_write); if (!bio) return ERR_PTR(-ENOMEM); diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 5e3fabacefb5..abfb80ca7673 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -2749,7 +2749,7 @@ int f2fs_restore_node_summary(struct f2fs_sb_info *sbi, sum_entry = &sum->entries[0]; for (i = 0; i < last_offset; i += nrpages, addr += nrpages) { - nrpages = min(last_offset - i, BIO_MAX_PAGES); + nrpages = bio_limit(last_offset - i); /* readahead node pages */ f2fs_ra_meta_pages(sbi, addr, nrpages, META_POR, true); diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 16a1e82e3aeb..7e15d22a1a67 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -278,14 +278,14 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, if (!is_contig || bio_full(ctx->bio, plen)) { gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL); gfp_t orig_gfp = gfp; - int nr_vecs = (length + PAGE_SIZE - 1) >> PAGE_SHIFT; + unsigned int nr_vecs = (length + PAGE_SIZE - 1) >> PAGE_SHIFT; if (ctx->bio) submit_bio(ctx->bio); if (ctx->rac) /* same as readahead_gfp_mask */ gfp |= __GFP_NORETRY | __GFP_NOWARN; - ctx->bio = bio_alloc(gfp, min(BIO_MAX_PAGES, nr_vecs)); + ctx->bio = bio_alloc(gfp, bio_limit(nr_vecs)); /* * If the bio_alloc fails, try it again for a single page to * avoid having to deal with partial page reads. This emulates diff --git a/fs/mpage.c b/fs/mpage.c index 830e6cc2a9e7..34b96cd1cc27 100644 --- a/fs/mpage.c +++ b/fs/mpage.c @@ -304,9 +304,7 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args) goto out; } args->bio = mpage_alloc(bdev, blocks[0] << (blkbits - 9), - min_t(int, args->nr_pages, - BIO_MAX_PAGES), - gfp); + bio_limit(args->nr_pages), gfp); if (args->bio == NULL) goto confused; } diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c index 3be6836074ae..176a1ee508a4 100644 --- a/fs/nfs/blocklayout/blocklayout.c +++ b/fs/nfs/blocklayout/blocklayout.c @@ -115,13 +115,13 @@ bl_submit_bio(struct bio *bio) return NULL; } -static struct bio * -bl_alloc_init_bio(int npg, struct block_device *bdev, sector_t disk_sector, +static struct bio *bl_alloc_init_bio(unsigned int npg, + struct block_device *bdev, sector_t disk_sector, bio_end_io_t end_io, struct parallel_io *par) { struct bio *bio; - npg = min(npg, BIO_MAX_PAGES); + npg = bio_limit(npg); bio = bio_alloc(GFP_NOIO, npg); if (!bio && (current->flags & PF_MEMALLOC)) { while (!bio && (npg /= 2)) diff --git a/fs/xfs/xfs_bio_io.c b/fs/xfs/xfs_bio_io.c index e2148f2d5d6b..50c0002404aa 100644 --- a/fs/xfs/xfs_bio_io.c +++ b/fs/xfs/xfs_bio_io.c @@ -6,7 +6,7 @@ static inline unsigned int bio_max_vecs(unsigned int count) { - return min_t(unsigned, howmany(count, PAGE_SIZE), BIO_MAX_PAGES); + return bio_limit(howmany(count, PAGE_SIZE)); } int diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index f8400bbd6473..70b3b478e547 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -1480,7 +1480,7 @@ xfs_buf_ioapply_map( int op) { int page_index; - int total_nr_pages = bp->b_page_count; + unsigned int total_nr_pages = bp->b_page_count; int nr_pages; struct bio *bio; sector_t sector = bp->b_maps[map].bm_bn; @@ -1505,7 +1505,7 @@ xfs_buf_ioapply_map( next_chunk: atomic_inc(&bp->b_io_remaining); - nr_pages = min(total_nr_pages, BIO_MAX_PAGES); + nr_pages = bio_limit(total_nr_pages); bio = bio_alloc(GFP_NOIO, nr_pages); bio_set_dev(bio, bp->b_target->bt_bdev); diff --git a/include/linux/bio.h b/include/linux/bio.h index 1edda614f7ce..f4e256ffd128 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -19,7 +19,12 @@ #define BIO_BUG_ON #endif -#define BIO_MAX_PAGES 256 +#define BIO_MAX_PAGES 256U + +static inline unsigned int bio_limit(unsigned int nr_segs) +{ + return min(nr_segs, BIO_MAX_PAGES); +} #define bio_prio(bio) (bio)->bi_ioprio #define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio)