Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754341AbZGLNDg (ORCPT ); Sun, 12 Jul 2009 09:03:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751953AbZGLND0 (ORCPT ); Sun, 12 Jul 2009 09:03:26 -0400 Received: from ip67-152-220-66.z220-152-67.customer.algx.net ([67.152.220.66]:7739 "EHLO daytona.int.panasas.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751849AbZGLNDX (ORCPT ); Sun, 12 Jul 2009 09:03:23 -0400 Message-ID: <4A59DF14.7060807@panasas.com> Date: Sun, 12 Jul 2009 16:03:16 +0300 From: Boaz Harrosh User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1b3pre) Gecko/20090315 Remi/3.0-0.b2.fc10.remi Thunderbird/3.0b2 MIME-Version: 1.0 To: Vladislav Bolkhovitin CC: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, scst-devel@lists.sourceforge.net, Tejun Heo , James Bottomley , FUJITA Tomonori , Jens Axboe Subject: Re: [PATCH]: New implementation of scsi_execute_async() References: <4A563368.5040407@vlnb.net> In-Reply-To: <4A563368.5040407@vlnb.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 12 Jul 2009 13:03:19.0097 (UTC) FILETIME=[209C5290:01CA02F1] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 24375 Lines: 836 On 07/09/2009 09:14 PM, Vladislav Bolkhovitin wrote: > This patch reimplements scsi_execute_async(). In the new version it's a lot less > hackish and also has additional features. Namely: > > 1. Possibility to insert commands both in tail and in head of the queue. > > 2. Possibility to explicitly specify if the last SG element has space for padding. > > This patch based on the previous patches posted by Tejun Heo. Comparing to them > it has the following improvements: > > 1. It uses BIOs chaining instead of kmalloc()ing the whole bio. > > 2. It uses SGs chaining instead of kmalloc()ing one big SG in case if direct > mapping failed (e.g. because of DMA alignment or padding). > > 3. If direct mapping failed, if possible, it copies only the last SG element, > not the whole SG. > > Also this patch adds and exports function blk_copy_sg(), which copies one SG to > another. > > At the moment SCST is the only user of this functionality. It needs it, because > its target drivers, which are, basically, SCSI drivers, can deal only with SGs, > not with BIOs. But, according the latest discussions, there are other potential > users for of this functionality, so I'm sending this patch in a hope that it will be > also useful for them and eventually will be merged in the mainline kernel. > > This patch requires previously sent patch with subject "[PATCH]: Rename REQ_COPY_USER > to more descriptive REQ_HAS_TAIL_SPACE_FOR_PADDING". > > It's against 2.6.30.1, but if necessary, I can update it to any necessary > kernel version. > > Signed-off-by: Vladislav Bolkhovitin > > block/blk-map.c | 536 +++++++++++++++++++++++++++++++++++++++++++++ > drivers/scsi/scsi_lib.c | 108 ++++++++- > include/linux/blkdev.h | 6 > include/scsi/scsi_device.h | 11 > 4 files changed, 660 insertions(+), 1 deletion(-) > The scsi bits are not needed and just add complexity. allocate the request, call blk_rq_map_kern_sg() and blk_execute_xxx directly from your driver. Since you exacly know your code path lots of if(s) and flags are saved and that ugly scsi_io_context allocation. If you absolutely need that scsi_normalize_sense() of scsi_execute_req call it from driver, its already exported. > diff -upkr linux-2.6.30.1/block/blk-map.c linux-2.6.30.1/block/blk-map.c > --- linux-2.6.30.1/block/blk-map.c 2009-06-10 07:05:27.000000000 +0400 > +++ linux-2.6.30.1/block/blk-map.c 2009-07-09 21:33:07.000000000 +0400 > @@ -5,6 +5,7 @@ > #include > #include > #include > +#include > #include /* for struct sg_iovec */ > > #include "blk.h" > @@ -273,6 +274,541 @@ int blk_rq_unmap_user(struct bio *bio) > EXPORT_SYMBOL(blk_rq_unmap_user); > > /** > + * blk_copy_sg - copy one SG vector to another > + * @dst_sg: destination SG > + * @src_sg: source SG > + * @copy_len: maximum amount of data to copy. If 0, then copy all. > + * @d_km_type: kmap_atomic type for the destination SG > + * @s_km_type: kmap_atomic type for the source SG > + * > + * Description: > + * Data from the destination SG vector will be copied to the source SG > + * vector. End of the vectors will be determined by sg_next() returning > + * NULL. Returns number of bytes copied. > + */ > +int blk_copy_sg(struct scatterlist *dst_sg, > + struct scatterlist *src_sg, size_t copy_len, > + enum km_type d_km_type, enum km_type s_km_type) > +{ > + int res = 0; > + size_t src_len, dst_len, src_offs, dst_offs; > + struct page *src_page, *dst_page; > + > + if (copy_len == 0) > + copy_len = 0x7FFFFFFF; /* copy all */ > + > + dst_page = sg_page(dst_sg); > + dst_len = dst_sg->length; > + dst_offs = dst_sg->offset; > + > + src_offs = 0; > + do { > + src_page = sg_page(src_sg); > + src_len = src_sg->length; > + src_offs = src_sg->offset; > + > + do { > + void *saddr, *daddr; > + size_t n; > + > + saddr = kmap_atomic(src_page, s_km_type) + src_offs; > + daddr = kmap_atomic(dst_page, d_km_type) + dst_offs; > + > + if ((src_offs == 0) && (dst_offs == 0) && > + (src_len >= PAGE_SIZE) && (dst_len >= PAGE_SIZE) && > + (copy_len >= PAGE_SIZE)) { > + copy_page(daddr, saddr); > + n = PAGE_SIZE; > + } else { > + n = min_t(size_t, PAGE_SIZE - dst_offs, > + PAGE_SIZE - src_offs); > + n = min(n, src_len); > + n = min(n, dst_len); > + n = min_t(size_t, n, copy_len); > + memcpy(daddr, saddr, n); > + dst_offs += n; > + src_offs += n; > + } > + > + kunmap_atomic(saddr, s_km_type); > + kunmap_atomic(daddr, d_km_type); > + > + res += n; > + copy_len -= n; > + if (copy_len == 0) > + goto out; > + > + if ((src_offs & ~PAGE_MASK) == 0) { > + src_page = nth_page(src_page, 1); > + src_offs = 0; > + } > + if ((dst_offs & ~PAGE_MASK) == 0) { > + dst_page = nth_page(dst_page, 1); > + dst_offs = 0; > + } > + > + src_len -= n; > + dst_len -= n; > + if (dst_len == 0) { > + dst_sg = sg_next(dst_sg); > + if (dst_sg == NULL) > + goto out; > + dst_page = sg_page(dst_sg); > + dst_len = dst_sg->length; > + dst_offs = dst_sg->offset; > + } > + } while (src_len > 0); > + > + src_sg = sg_next(src_sg); > + } while (src_sg != NULL); > + > +out: > + return res; > +} > +EXPORT_SYMBOL(blk_copy_sg); > + This has nothing to do with block layer lib/scatterlist.c is a better candidate. see if you can refactor it better together with sg_copy_to/from_buffer > +/** > + * blk_rq_unmap_kern_sg - "unmaps" data buffers in the request > + * @req: request to unmap > + * @do_copy: sets copy data between buffers, if needed, or not > + * > + * Description: > + * It frees all additional buffers allocated for SG->BIO mapping. > + */ > +void blk_rq_unmap_kern_sg(struct request *req, int do_copy) > +{ > + struct scatterlist *hdr = (struct scatterlist *)req->end_io_data; > + You can't use req->end_io_data here! req->end_io_data is reserved for blk_execute_async callers. It can not be used for private block use. (Don't you use it in this patchset from scsi_execute_async ?) > + if (hdr == NULL) > + goto out; > + > + if (hdr->length == 0) { > + /* Tail element only was copied */ > + struct scatterlist *new_sg = &hdr[1]; > + struct scatterlist *orig_sg = (struct scatterlist *)hdr->page_link; > + I don't like that overloading of (scatterlist *) like that. Put a well defined struct or union with proper flags and types, so all possibilities are clear at both sides of the code. Document that structure for the different options. > + if ((rq_data_dir(req) == READ) && do_copy) { > + void *saddr, *daddr; > + > + saddr = kmap_atomic(sg_page(orig_sg), KM_BIO_SRC_IRQ); > + daddr = kmap_atomic(sg_page(new_sg), KM_BIO_DST_IRQ) + > + new_sg->offset; > + memcpy(daddr, saddr, orig_sg->length); > + kunmap_atomic(saddr, KM_BIO_SRC_IRQ); > + kunmap_atomic(daddr, KM_BIO_DST_IRQ); > + } > + > + __free_pages(sg_page(orig_sg), get_order(orig_sg->length)); > + *orig_sg = *new_sg; > + kfree(hdr); > + } else { > + /* The whole SG was copied */ > + struct scatterlist *new_sgl = &hdr[1]; > + struct scatterlist *orig_sgl = (struct scatterlist *)hdr->page_link; > + struct scatterlist *sg, *start_sg; Here too ugly as hell, use a proper structure with the needed types. > + int n; > + > + if ((rq_data_dir(req) == READ) && do_copy) { > + blk_copy_sg(orig_sgl, new_sgl, 0, KM_BIO_DST_IRQ, > + KM_BIO_SRC_IRQ); > + } > + > + start_sg = hdr; > + sg = new_sgl; > + n = 1; > + while (sg != NULL) { > + __free_page(sg_page(sg)); > + sg = sg_next(sg); > + n++; > + /* One entry for chaining */ > + if ((sg == NULL) || (n == (SG_MAX_SINGLE_ALLOC - 1))) { > + kfree(start_sg); > + start_sg = sg; > + n = 0; > + } > + } > + } > + > +out: > + return; > +} > +EXPORT_SYMBOL(blk_rq_unmap_kern_sg); > + > +static int blk_rq_handle_align_tail_only(struct request *rq, > + struct scatterlist *sg_to_copy, > + gfp_t gfp, gfp_t page_gfp) > +{ > + int res = 0; > + struct scatterlist *tail_sg = sg_to_copy; > + struct scatterlist *new_sg; > + struct scatterlist *hdr; > + int new_sg_nents; > + struct page *pg; > + > + new_sg_nents = 2; > + > + new_sg = kmalloc(sizeof(*new_sg) * new_sg_nents, gfp); > + if (new_sg == NULL) > + goto out_nomem; > + > + sg_init_table(new_sg, new_sg_nents); > + > + hdr = new_sg; > + new_sg++; > + new_sg_nents--; > + > + hdr->page_link = (unsigned long)tail_sg; > + *new_sg = *tail_sg; > + > + pg = alloc_pages(page_gfp, get_order(tail_sg->length)); > + if (pg == NULL) > + goto err_free_new_sg; > + > + if (rq_data_dir(rq) == WRITE) { > + void *saddr, *daddr; > + saddr = kmap_atomic(sg_page(tail_sg), KM_USER0) + > + tail_sg->offset; > + daddr = kmap_atomic(pg, KM_USER1); > + memcpy(daddr, saddr, tail_sg->length); > + kunmap_atomic(saddr, KM_USER0); > + kunmap_atomic(daddr, KM_USER1); > + } > + > + sg_assign_page(tail_sg, pg); > + tail_sg->offset = 0; > + > + rq->end_io_data = hdr; > + rq->cmd_flags |= REQ_HAS_TAIL_SPACE_FOR_PADDING; > + > +out: > + return res; > + > +err_free_new_sg: > + kfree(new_sg); > + > +out_nomem: > + res = -ENOMEM; > + goto out; > +} > + > +static int blk_rq_handle_align(struct request *rq, struct scatterlist **psgl, > + int *pnents, struct scatterlist *sgl_to_copy, > + int nents_to_copy, gfp_t gfp, gfp_t page_gfp) > +{ > + int res = 0, i; > + struct scatterlist *sgl = *psgl; > + int nents = *pnents; > + struct scatterlist *sg, *prev_sg; > + struct scatterlist *new_sgl; > + struct scatterlist *hdr; > + size_t len = 0, to_copy; > + int new_sgl_nents, new_sgl_nents_to_alloc, n; > + below should use the sg_alloc_table / sg_free_table constructs for the proper chaining/setting of scatterlist chains. Failing to do so is both a code duplication and hinder of future changes to these constructs. see all places that use sg_alloc_table/sg_free_table in source like scsi_lib.c. I'll stop the review here. You need to solve the req->end_io_data use and change this to sg_alloc_table/sg_free_table (perhaps the one with the callback i'm not sure) I'll continue review on the next patchset. Cheers Boaz > + if (sgl != sgl_to_copy) { > + /* Copy only the last element */ > + res = blk_rq_handle_align_tail_only(rq, sgl_to_copy, > + gfp, page_gfp); > + if (res == 0) > + goto out; > + } > + > + for_each_sg(sgl, sg, nents, i) > + len += sg->length; > + to_copy = len; > + > + /* > + * Let's keep each SG allocation inside a single page to decrease > + * probability of failure. > + */ > + > + new_sgl_nents = PFN_UP(len) + 1; > + new_sgl_nents_to_alloc = new_sgl_nents + > + ((new_sgl_nents - 1) / SG_MAX_SINGLE_ALLOC); > + n = min_t(size_t, SG_MAX_SINGLE_ALLOC, new_sgl_nents_to_alloc); > + > + new_sgl = kmalloc(sizeof(*new_sgl) * n, gfp); > + if (new_sgl == NULL) > + goto out_nomem; > + > + sg_init_table(new_sgl, n); > + > + new_sgl_nents_to_alloc -= n; > + sg = new_sgl; > + while (new_sgl_nents_to_alloc > 0) { > + prev_sg = sg; > + n = min_t(size_t, SG_MAX_SINGLE_ALLOC, new_sgl_nents_to_alloc); > + > + sg = kmalloc(sizeof(*sg) * n, gfp); > + if (sg == NULL) > + goto out_nomem; > + > + sg_init_table(sg, n); > + sg_chain(prev_sg, SG_MAX_SINGLE_ALLOC, sg); > + > + new_sgl_nents_to_alloc -= n; > + }; > + > + hdr = new_sgl; > + new_sgl++; > + new_sgl_nents--; > + > + hdr->page_link = (unsigned long)sgl; > + hdr->length = nents; > + > + for_each_sg(new_sgl, sg, new_sgl_nents, i) { > + struct page *pg; > + > + pg = alloc_page(page_gfp); > + if (pg == NULL) > + goto err_free_new_sgl; > + > + sg_assign_page(sg, pg); > + sg->length = min_t(size_t, PAGE_SIZE, len); > + > + len -= PAGE_SIZE; > + } > + > + if (rq_data_dir(rq) == WRITE) { > + /* > + * We need to limit amount of copied data to to_copy, because > + * sgl might have the last element not marked as last in > + * SG chaining. > + */ > + blk_copy_sg(new_sgl, sgl, to_copy, KM_USER0, KM_USER1); > + } > + > + rq->end_io_data = hdr; > + rq->cmd_flags |= REQ_HAS_TAIL_SPACE_FOR_PADDING; > + > + *psgl = new_sgl; > + *pnents = new_sgl_nents; > + > +out: > + return res; > + > +err_free_new_sgl: > + for_each_sg(new_sgl, sg, new_sgl_nents, i) { > + struct page *pg = sg_page(sg); > + if (pg == NULL) > + break; > + __free_page(pg); > + } > + > +out_nomem: > + res = -ENOMEM; > + goto out; > +} > + > +static void bio_map_kern_endio(struct bio *bio, int err) > +{ > + bio_put(bio); > +} > + > +static int __blk_rq_map_kern_sg(struct request *rq, struct scatterlist *sgl, > + int nents, gfp_t gfp, struct scatterlist **sgl_to_copy, > + int *nents_to_copy) > +{ > + int res; > + struct request_queue *q = rq->q; > + int rw = rq_data_dir(rq); > + int max_nr_vecs, i; > + size_t tot_len; > + bool need_new_bio; > + struct scatterlist *sg, *prev_sg = NULL; > + struct bio *bio = NULL, *hbio = NULL, *tbio = NULL; > + > + *sgl_to_copy = NULL; > + > + if (unlikely((sgl == 0) || (nents <= 0))) { > + WARN_ON(1); > + res = -EINVAL; > + goto out; > + } > + > + /* > + * Let's keep each bio allocation inside a single page to decrease > + * probability of failure. > + */ > + max_nr_vecs = min_t(size_t, > + ((PAGE_SIZE - sizeof(struct bio)) / sizeof(struct bio_vec)), > + BIO_MAX_PAGES); > + > + need_new_bio = true; > + tot_len = 0; > + for_each_sg(sgl, sg, nents, i) { > + struct page *page = sg_page(sg); > + void *page_addr = page_address(page); > + size_t len = sg->length, l; > + size_t offset = sg->offset; > + > + tot_len += len; > + prev_sg = sg; > + > + /* > + * Each segment must be aligned on DMA boundary and > + * not on stack. The last one may have unaligned > + * length as long as the total length is aligned to > + * DMA padding alignment. > + */ > + if (i == nents - 1) > + l = 0; > + else > + l = len; > + if (((sg->offset | l) & queue_dma_alignment(q)) || > + (page_addr && object_is_on_stack(page_addr + sg->offset))) { > + res = -EINVAL; > + goto out_need_copy; > + } > + > + while (len > 0) { > + size_t bytes; > + int rc; > + > + if (need_new_bio) { > + bio = bio_kmalloc(gfp, max_nr_vecs); > + if (bio == NULL) { > + res = -ENOMEM; > + goto out_free_bios; > + } > + > + if (rw == WRITE) > + bio->bi_rw |= 1 << BIO_RW; > + > + bio->bi_end_io = bio_map_kern_endio; > + > + if (hbio == NULL) > + hbio = tbio = bio; > + else > + tbio = tbio->bi_next = bio; > + } > + > + bytes = min_t(size_t, len, PAGE_SIZE - offset); > + > + rc = bio_add_pc_page(q, bio, page, bytes, offset); > + if (rc < bytes) { > + if (unlikely(need_new_bio || (rc < 0))) { > + if (rc < 0) > + res = rc; > + else > + res = -EIO; > + goto out_need_copy; > + } else { > + need_new_bio = true; > + len -= rc; > + offset += rc; > + continue; > + } > + } > + > + need_new_bio = false; > + offset = 0; > + len -= bytes; > + page = nth_page(page, 1); > + } > + } > + > + if (hbio == NULL) { > + res = -EINVAL; > + goto out_free_bios; > + } > + > + /* Total length must be aligned on DMA padding alignment */ > + if ((tot_len & q->dma_pad_mask) && > + !(rq->cmd_flags & REQ_HAS_TAIL_SPACE_FOR_PADDING)) { > + res = -EINVAL; > + if (sgl->offset == 0) { > + *sgl_to_copy = prev_sg; > + *nents_to_copy = 1; > + goto out_free_bios; > + } else > + goto out_need_copy; > + } > + > + while (hbio != NULL) { > + bio = hbio; > + hbio = hbio->bi_next; > + bio->bi_next = NULL; > + > + blk_queue_bounce(q, &bio); > + > + res = blk_rq_append_bio(q, rq, bio); > + if (unlikely(res != 0)) { > + bio->bi_next = hbio; > + hbio = bio; > + goto out_free_bios; > + } > + } > + > + rq->buffer = rq->data = NULL; > + > +out: > + return res; > + > +out_need_copy: > + *sgl_to_copy = sgl; > + *nents_to_copy = nents; > + > +out_free_bios: > + while (hbio != NULL) { > + bio = hbio; > + hbio = hbio->bi_next; > + bio_put(bio); > + } > + goto out; > +} > + > +/** > + * blk_rq_map_kern_sg - map kernel data to a request, for REQ_TYPE_BLOCK_PC > + * @rq: request to fill > + * @sgl: area to map > + * @nents: number of elements in @sgl > + * @gfp: memory allocation flags > + * > + * Description: > + * Data will be mapped directly if possible. Otherwise a bounce > + * buffer will be used. > + */ > +int blk_rq_map_kern_sg(struct request *rq, struct scatterlist *sgl, > + int nents, gfp_t gfp) > +{ > + int res; > + struct scatterlist *sg_to_copy = NULL; > + int nents_to_copy = 0; > + > + if (unlikely((sgl == 0) || (sgl->length == 0) || > + (nents <= 0) || (rq->end_io_data != NULL))) { > + WARN_ON(1); > + res = -EINVAL; > + goto out; > + } > + > + res = __blk_rq_map_kern_sg(rq, sgl, nents, gfp, &sg_to_copy, > + &nents_to_copy); > + if (unlikely(res != 0)) { > + if (sg_to_copy == NULL) > + goto out; > + > + res = blk_rq_handle_align(rq, &sgl, &nents, sg_to_copy, > + nents_to_copy, gfp, rq->q->bounce_gfp | gfp); > + if (unlikely(res != 0)) > + goto out; > + > + res = __blk_rq_map_kern_sg(rq, sgl, nents, gfp, &sg_to_copy, > + &nents_to_copy); > + if (res != 0) { > + blk_rq_unmap_kern_sg(rq, 0); > + goto out; > + } > + } > + > + rq->buffer = rq->data = NULL; > + > +out: > + return res; > +} > +EXPORT_SYMBOL(blk_rq_map_kern_sg); > + > +/** > * blk_rq_map_kern - map kernel data to a request, for REQ_TYPE_BLOCK_PC usage > * @q: request queue where request should be inserted > * @rq: request to fill > diff -upkr linux-2.6.30.1/drivers/scsi/scsi_lib.c linux-2.6.30.1/drivers/scsi/scsi_lib.c > --- linux-2.6.30.1/drivers/scsi/scsi_lib.c 2009-06-10 07:05:27.000000000 +0400 > +++ linux-2.6.30.1/drivers/scsi/scsi_lib.c 2009-07-08 21:24:29.000000000 +0400 > @@ -277,6 +277,100 @@ int scsi_execute_req(struct scsi_device > } > EXPORT_SYMBOL(scsi_execute_req); > > +struct scsi_io_context { > + void *blk_data; > + void *data; > + void (*done)(void *data, char *sense, int result, int resid); > + char sense[SCSI_SENSE_BUFFERSIZE]; > +}; > + > +static struct kmem_cache *scsi_io_context_cache; > + > +static void scsi_end_async(struct request *req, int error) > +{ > + struct scsi_io_context *sioc = req->end_io_data; > + > + req->end_io_data = sioc->blk_data; > + blk_rq_unmap_kern_sg(req, (error == 0)); > + > + if (sioc->done) > + sioc->done(sioc->data, sioc->sense, req->errors, req->data_len); > + > + kmem_cache_free(scsi_io_context_cache, sioc); > + __blk_put_request(req->q, req); > +} > + > +/** > + * scsi_execute_async - insert request > + * @sdev: scsi device > + * @cmd: scsi command > + * @cmd_len: length of scsi cdb > + * @data_direction: DMA_TO_DEVICE, DMA_FROM_DEVICE, or DMA_NONE > + * @sgl: data buffer scatterlist > + * @nents: number of elements in the sgl > + * @timeout: request timeout in seconds > + * @retries: number of times to retry request > + * @privdata: data passed to done() > + * @done: callback function when done > + * @gfp: memory allocation flags > + * @flags: one or more SCSI_ASYNC_EXEC_FLAG_* flags > + */ > +int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd, > + int cmd_len, int data_direction, struct scatterlist *sgl, > + int nents, int timeout, int retries, void *privdata, > + void (*done)(void *, char *, int, int), gfp_t gfp, > + int flags) > +{ > + struct request *req; > + struct scsi_io_context *sioc; > + int err = 0; > + int write = (data_direction == DMA_TO_DEVICE); > + > + sioc = kmem_cache_zalloc(scsi_io_context_cache, gfp); > + if (sioc == NULL) > + return DRIVER_ERROR << 24; > + > + req = blk_get_request(sdev->request_queue, write, gfp); > + if (req == NULL) > + goto free_sense; > + req->cmd_type = REQ_TYPE_BLOCK_PC; > + req->cmd_flags |= REQ_QUIET; > + > + if (flags & SCSI_ASYNC_EXEC_FLAG_HAS_TAIL_SPACE_FOR_PADDING) > + req->cmd_flags |= REQ_HAS_TAIL_SPACE_FOR_PADDING; > + > + if (sgl != NULL) { > + err = blk_rq_map_kern_sg(req, sgl, nents, gfp); > + if (err) > + goto free_req; > + } > + > + sioc->blk_data = req->end_io_data; > + sioc->data = privdata; > + sioc->done = done; > + > + req->cmd_len = cmd_len; > + memset(req->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */ > + memcpy(req->cmd, cmd, req->cmd_len); > + req->sense = sioc->sense; > + req->sense_len = 0; > + req->timeout = timeout; > + req->retries = retries; > + req->end_io_data = sioc; > + > + blk_execute_rq_nowait(req->q, NULL, req, > + flags & SCSI_ASYNC_EXEC_FLAG_AT_HEAD, scsi_end_async); > + return 0; > + > +free_req: > + blk_put_request(req); > + > +free_sense: > + kmem_cache_free(scsi_io_context_cache, sioc); > + return DRIVER_ERROR << 24; > +} > +EXPORT_SYMBOL_GPL(scsi_execute_async); > + > /* > * Function: scsi_init_cmd_errh() > * > @@ -1743,12 +1837,20 @@ int __init scsi_init_queue(void) > { > int i; > > + scsi_io_context_cache = kmem_cache_create("scsi_io_context", > + sizeof(struct scsi_io_context), > + 0, 0, NULL); > + if (!scsi_io_context_cache) { > + printk(KERN_ERR "SCSI: can't init scsi io context cache\n"); > + return -ENOMEM; > + } > + > scsi_sdb_cache = kmem_cache_create("scsi_data_buffer", > sizeof(struct scsi_data_buffer), > 0, 0, NULL); > if (!scsi_sdb_cache) { > printk(KERN_ERR "SCSI: can't init scsi sdb cache\n"); > - return -ENOMEM; > + goto cleanup_io_context; > } > > for (i = 0; i < SG_MEMPOOL_NR; i++) { > @@ -1784,6 +1886,9 @@ cleanup_sdb: > } > kmem_cache_destroy(scsi_sdb_cache); > > +cleanup_io_context: > + kmem_cache_destroy(scsi_io_context_cache); > + > return -ENOMEM; > } > > @@ -1791,6 +1896,7 @@ void scsi_exit_queue(void) > { > int i; > > + kmem_cache_destroy(scsi_io_context_cache); > kmem_cache_destroy(scsi_sdb_cache); > > for (i = 0; i < SG_MEMPOOL_NR; i++) { > diff -upkr linux-2.6.30.1/include/linux/blkdev.h linux-2.6.30.1/include/linux/blkdev.h > --- linux-2.6.30.1/include/linux/blkdev.h 2009-06-10 07:05:27.000000000 +0400 > +++ linux-2.6.30.1/include/linux/blkdev.h 2009-07-08 21:24:29.000000000 +0400 > @@ -807,6 +807,9 @@ extern int blk_rq_map_kern(struct reques > extern int blk_rq_map_user_iov(struct request_queue *, struct request *, > struct rq_map_data *, struct sg_iovec *, int, > unsigned int, gfp_t); > +extern int blk_rq_map_kern_sg(struct request *rq, > + struct scatterlist *sgl, int nents, gfp_t gfp); > +extern void blk_rq_unmap_kern_sg(struct request *req, int do_copy); > extern int blk_execute_rq(struct request_queue *, struct gendisk *, > struct request *, int); > extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, > @@ -909,6 +912,9 @@ extern void blk_dump_rq_flags(struct req > extern void generic_unplug_device(struct request_queue *); > extern long nr_blockdev_pages(void); > > +extern int blk_copy_sg(struct scatterlist *, struct scatterlist *, size_t, > + enum km_type, enum km_type); > + > int blk_get_queue(struct request_queue *); > struct request_queue *blk_alloc_queue(gfp_t); > struct request_queue *blk_alloc_queue_node(gfp_t, int); > diff -upkr linux-2.6.30.1/include/scsi/scsi_device.h linux-2.6.30.1/include/scsi/scsi_device.h > --- linux-2.6.30.1/include/scsi/scsi_device.h 2009-06-10 07:05:27.000000000 +0400 > +++ linux-2.6.30.1/include/scsi/scsi_device.h 2009-07-08 21:24:29.000000000 +0400 > @@ -372,6 +372,17 @@ extern int scsi_execute_req(struct scsi_ > struct scsi_sense_hdr *, int timeout, int retries, > int *resid); > > +#define SCSI_ASYNC_EXEC_FLAG_AT_HEAD 1 > +#define SCSI_ASYNC_EXEC_FLAG_HAS_TAIL_SPACE_FOR_PADDING 2 > + > +#define SCSI_EXEC_REQ_FIFO_DEFINED > +extern int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd, > + int cmd_len, int data_direction, > + struct scatterlist *sgl, int nents, int timeout, > + int retries, void *privdata, > + void (*done)(void *, char *, int, int), > + gfp_t gfp, int flags); > + > static inline int __must_check scsi_device_reprobe(struct scsi_device *sdev) > { > return device_reprobe(&sdev->sdev_gendev); > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/