From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754436AbbAPMF4 (ORCPT ); Fri, 16 Jan 2015 07:05:56 -0500 Received: from casper.infradead.org ([85.118.1.10]:44167 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751894AbbAPMFy (ORCPT ); Fri, 16 Jan 2015 07:05:54 -0500 From: Christoph Hellwig To: Jens Axboe , Dongsu Park Cc: Kent Overstreet , linux-kernel@vger.kernel.org Subject: [PATCH 1/7] block: simplify bio_map_kern Date: Fri, 16 Jan 2015 13:04:49 +0100 Message-Id: <1421409895-21377-2-git-send-email-hch@lst.de> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1421409895-21377-1-git-send-email-hch@lst.de> References: <1421409895-21377-1-git-send-email-hch@lst.de> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Just open code the trivial mapping from a kernel virtual address to a bio instead of going through the complex user address mapping machinery. Signed-off-by: Christoph Hellwig --- block/bio.c | 60 ++++++++++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 44 insertions(+), 16 deletions(-) diff --git a/block/bio.c b/block/bio.c index 471d738..54da51e 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1563,9 +1563,8 @@ static void bio_copy_kern_endio(struct bio *bio, int err) { struct bio_vec *bvec; const int read = bio_data_dir(bio) == READ; - struct bio_map_data *bmd = bio->bi_private; + char *p = bio->bi_private; int i; - char *p = bmd->sgvecs[0].iov_base; bio_for_each_segment_all(bvec, bio, i) { char *addr = page_address(bvec->bv_page); @@ -1577,7 +1576,6 @@ static void bio_copy_kern_endio(struct bio *bio, int err) p += bvec->bv_len; } - kfree(bmd); bio_put(bio); } @@ -1595,28 +1593,58 @@ static void bio_copy_kern_endio(struct bio *bio, int err) struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len, gfp_t gfp_mask, int reading) { - struct bio *bio; + unsigned long kaddr = (unsigned long)data; + unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; + unsigned long start = kaddr >> PAGE_SHIFT; struct bio_vec *bvec; - int i; + struct bio *bio; + void *p = data; + int nr_pages = 0, i; - bio = bio_copy_user(q, NULL, (unsigned long)data, len, 1, gfp_mask); - if (IS_ERR(bio)) - return bio; + /* + * Overflow, abort + */ + if (end < start) + return ERR_PTR(-EINVAL); - if (!reading) { - void *p = data; + nr_pages = end - start; + bio = bio_kmalloc(gfp_mask, nr_pages); + if (!bio) + return ERR_PTR(-ENOMEM); - bio_for_each_segment_all(bvec, bio, i) { - char *addr = page_address(bvec->bv_page); + while (len) { + struct page *page; + unsigned int bytes = PAGE_SIZE; - memcpy(addr, p, bvec->bv_len); - p += bvec->bv_len; - } + if (bytes > len) + bytes = len; + + page = alloc_page(q->bounce_gfp | gfp_mask); + if (!page) + goto cleanup; + + if (!reading) + memcpy(page_address(page), p, bytes); + + if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) + break; + + len -= bytes; + p += bytes; } - bio->bi_end_io = bio_copy_kern_endio; + if (!reading) + bio->bi_rw |= REQ_WRITE; + bio->bi_private = data; + bio->bi_end_io = bio_copy_kern_endio; return bio; + +cleanup: + bio_for_each_segment_all(bvec, bio, i) + __free_page(bvec->bv_page); + bio_put(bio); + return ERR_PTR(-ENOMEM); } EXPORT_SYMBOL(bio_copy_kern); -- 1.9.1