* Nicholas A. Bellinger | 2011-11-30 00:26:09 [-0800]: >Mmmm, this patch doesn't apply against recent lio-core.git/master. What >HEAD commit are you using..? I'm using |commit c387271e860c14d91c99be42ab4564e4b865fd87 |Author: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx> |Date: Mon Nov 28 16:58:47 2011 -0800 | | Revert "iscsi-target: Make kernel_setsockopt value endian-safe" from git://git.kernel.org/pub/scm/linux/kernel/git/nab/lio-core.git >When you have a moment, please check this applies against master. >Otherwise I'm fine with merging it by hand. I just looked over the patch. You probably get a conflict you need don't apply "target/rd: simplify the page/offset computation". Jörn been suggesting using ">> PAGE_SHIFT" and " & ~PAGE_MASK" instead of the do_div() macro. The compiler should do this kind of replacement. So if you like another version, please let me know. In the meantime I merged the two parts of this patch (sg_next() replacement and copy rewrite) and here it is in case you don't want break bisecting and I can't prove that it is correct since it never worked for me >From 73fa3d6863be28346d2158541525924773648e62 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Date: Fri, 25 Nov 2011 12:35:18 +0100 Subject: [PATCH] target/rd: fix or rewrite the copy routine During mkfs.ext4 /dev/sda1 I run into: | page: 69, remaining size: 18432, length: 2048, i: 126, j: 63 | Step 2 - sg_s[126]: deb09890 length: 2048 offset: 0 sg_d[63].length: 4096 | Step 2 - length: 2048 src_offset: 0 dst_offset: 2048 | page: 69, remaining size: 16384, length: 2048, i: 127, j: 64 | page: 70 in same page table | Step 1 - sg_s[127]: deb098a8 length: 0 offset: 0 sg_d[64].length: 4096 | Step 1 - length: 0 src_offset: 0 dst_offset: 0 | ------------[ cut here ]------------ | kernel BUG at include/linux/scatterlist.h:97! | invalid opcode: 0000 [#5] PREEMPT SMP | EIP is at rd_MEMCPY_do_task+0x780/0x790 [target_core_mod] | [<e0ab38d4>] __transport_execute_tasks+0xd4/0x190 [target_core_mod] So the code assumes that the sg list is only a array while in reality somebody chained it. Using sg_next() works properly and patch makes such a change. With this patch the bug goes away. However after umount/mount of the device my files are gone. So something is still not right. After looking at it for a while I decided to rewrite the that part of the code and now things do work for me. For reference: - http://article.gmane.org/gmane.linux.scsi.target.devel/595 the sg_next() conversion - http://article.gmane.org/gmane.linux.scsi.target.devel/602 the rewrite of the copy code Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> --- drivers/target/target_core_rd.c | 245 +++++++-------------------------------- 1 files changed, 40 insertions(+), 205 deletions(-) diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c index 95ce47f..1d2c4b6 100644 --- a/drivers/target/target_core_rd.c +++ b/drivers/target/target_core_rd.c @@ -341,235 +341,74 @@ static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page) return NULL; } -/* rd_MEMCPY_read(): - * - * - */ -static int rd_MEMCPY_read(struct rd_request *req) +static int rd_MEMCPY(struct rd_request *req, u32 read_rd) { struct se_task *task = &req->rd_task; struct rd_dev *dev = req->rd_task.task_se_cmd->se_dev->dev_ptr; struct rd_dev_sg_table *table; - struct scatterlist *sg_d, *sg_s; - void *dst, *src; - u32 i = 0, j = 0, dst_offset = 0, src_offset = 0; - u32 length, page_end = 0, table_sg_end; + struct scatterlist *rd_sg; + struct sg_mapping_iter m; u32 rd_offset = req->rd_offset; + u32 src_len; table = rd_get_sg_table(dev, req->rd_page); if (!table) return -EINVAL; - table_sg_end = (table->page_end_offset - req->rd_page); - sg_d = task->task_sg; - sg_s = &table->sg_table[req->rd_page - table->page_start_offset]; + rd_sg = &table->sg_table[req->rd_page - table->page_start_offset]; - pr_debug("RD[%u]: Read LBA: %llu, Size: %u Page: %u, Offset:" - " %u\n", dev->rd_dev_id, task->task_lba, req->rd_size, - req->rd_page, req->rd_offset); - - src_offset = rd_offset; + pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n", + dev->rd_dev_id, read_rd ? "Read" : "Write", + task->task_lba, req->rd_size, req->rd_page, + rd_offset); + src_len = PAGE_SIZE - rd_offset; + sg_miter_start(&m, task->task_sg, task->task_sg_nents, + read_rd ? SG_MITER_TO_SG : SG_MITER_FROM_SG); while (req->rd_size) { - if ((sg_d[i].length - dst_offset) < - (sg_s[j].length - src_offset)) { - length = (sg_d[i].length - dst_offset); - - pr_debug("Step 1 - sg_d[%d]: %p length: %d" - " offset: %u sg_s[%d].length: %u\n", i, - &sg_d[i], sg_d[i].length, sg_d[i].offset, j, - sg_s[j].length); - pr_debug("Step 1 - length: %u dst_offset: %u" - " src_offset: %u\n", length, dst_offset, - src_offset); - - if (length > req->rd_size) - length = req->rd_size; - - dst = sg_virt(&sg_d[i++]) + dst_offset; - BUG_ON(!dst); - - src = sg_virt(&sg_s[j]) + src_offset; - BUG_ON(!src); - - dst_offset = 0; - src_offset = length; - page_end = 0; - } else { - length = (sg_s[j].length - src_offset); - - pr_debug("Step 2 - sg_d[%d]: %p length: %d" - " offset: %u sg_s[%d].length: %u\n", i, - &sg_d[i], sg_d[i].length, sg_d[i].offset, - j, sg_s[j].length); - pr_debug("Step 2 - length: %u dst_offset: %u" - " src_offset: %u\n", length, dst_offset, - src_offset); - - if (length > req->rd_size) - length = req->rd_size; - - dst = sg_virt(&sg_d[i]) + dst_offset; - BUG_ON(!dst); - - if (sg_d[i].length == length) { - i++; - dst_offset = 0; - } else - dst_offset = length; - - src = sg_virt(&sg_s[j++]) + src_offset; - BUG_ON(!src); - - src_offset = 0; - page_end = 1; - } + u32 len; + void *rd_addr; - memcpy(dst, src, length); + sg_miter_next(&m); + len = min(m.length, src_len); + m.consumed = len; - pr_debug("page: %u, remaining size: %u, length: %u," - " i: %u, j: %u\n", req->rd_page, - (req->rd_size - length), length, i, j); + rd_addr = sg_virt(rd_sg) + rd_offset; - req->rd_size -= length; - if (!req->rd_size) - return 0; + if (read_rd) + memcpy(m.addr, rd_addr, len); + else + memcpy(rd_addr, m.addr, len); - if (!page_end) + req->rd_size -= len; + if (!req->rd_size) continue; - if (++req->rd_page <= table->page_end_offset) { - pr_debug("page: %u in same page table\n", - req->rd_page); + src_len -= len; + if (src_len) { + rd_offset += len; continue; } - pr_debug("getting new page table for page: %u\n", - req->rd_page); - - table = rd_get_sg_table(dev, req->rd_page); - if (!table) - return -EINVAL; - - sg_s = &table->sg_table[j = 0]; - } - - return 0; -} - -/* rd_MEMCPY_write(): - * - * - */ -static int rd_MEMCPY_write(struct rd_request *req) -{ - struct se_task *task = &req->rd_task; - struct rd_dev *dev = req->rd_task.task_se_cmd->se_dev->dev_ptr; - struct rd_dev_sg_table *table; - struct scatterlist *sg_d, *sg_s; - void *dst, *src; - u32 i = 0, j = 0, dst_offset = 0, src_offset = 0; - u32 length, page_end = 0, table_sg_end; - u32 rd_offset = req->rd_offset; - - table = rd_get_sg_table(dev, req->rd_page); - if (!table) - return -EINVAL; - - table_sg_end = (table->page_end_offset - req->rd_page); - sg_d = &table->sg_table[req->rd_page - table->page_start_offset]; - sg_s = task->task_sg; - - pr_debug("RD[%d] Write LBA: %llu, Size: %u, Page: %u," - " Offset: %u\n", dev->rd_dev_id, task->task_lba, req->rd_size, - req->rd_page, req->rd_offset); - - dst_offset = rd_offset; - - while (req->rd_size) { - if ((sg_s[i].length - src_offset) < - (sg_d[j].length - dst_offset)) { - length = (sg_s[i].length - src_offset); - - pr_debug("Step 1 - sg_s[%d]: %p length: %d" - " offset: %d sg_d[%d].length: %u\n", i, - &sg_s[i], sg_s[i].length, sg_s[i].offset, - j, sg_d[j].length); - pr_debug("Step 1 - length: %u src_offset: %u" - " dst_offset: %u\n", length, src_offset, - dst_offset); - - if (length > req->rd_size) - length = req->rd_size; - - src = sg_virt(&sg_s[i++]) + src_offset; - BUG_ON(!src); - - dst = sg_virt(&sg_d[j]) + dst_offset; - BUG_ON(!dst); - - src_offset = 0; - dst_offset = length; - page_end = 0; - } else { - length = (sg_d[j].length - dst_offset); - - pr_debug("Step 2 - sg_s[%d]: %p length: %d" - " offset: %d sg_d[%d].length: %u\n", i, - &sg_s[i], sg_s[i].length, sg_s[i].offset, - j, sg_d[j].length); - pr_debug("Step 2 - length: %u src_offset: %u" - " dst_offset: %u\n", length, src_offset, - dst_offset); - - if (length > req->rd_size) - length = req->rd_size; - - src = sg_virt(&sg_s[i]) + src_offset; - BUG_ON(!src); - - if (sg_s[i].length == length) { - i++; - src_offset = 0; - } else - src_offset = length; - - dst = sg_virt(&sg_d[j++]) + dst_offset; - BUG_ON(!dst); - - dst_offset = 0; - page_end = 1; - } - - memcpy(dst, src, length); - - pr_debug("page: %u, remaining size: %u, length: %u," - " i: %u, j: %u\n", req->rd_page, - (req->rd_size - length), length, i, j); - - req->rd_size -= length; - if (!req->rd_size) - return 0; - - if (!page_end) - continue; - - if (++req->rd_page <= table->page_end_offset) { - pr_debug("page: %u in same page table\n", - req->rd_page); + /* rd page completed, next one please */ + req->rd_page++; + rd_offset = 0; + src_len = PAGE_SIZE; + if (req->rd_page <= table->page_end_offset) { + rd_sg++; continue; } - pr_debug("getting new page table for page: %u\n", - req->rd_page); - table = rd_get_sg_table(dev, req->rd_page); - if (!table) + if (!table) { + sg_miter_stop(&m); return -EINVAL; + } - sg_d = &table->sg_table[j = 0]; + /* since we increment, the first sg entry is correct */ + rd_sg = table->sg_table; } - + sg_miter_stop(&m); return 0; } @@ -589,11 +428,7 @@ static int rd_MEMCPY_do_task(struct se_task *task) req->rd_page = tmp; req->rd_size = task->task_size; - if (task->task_data_direction == DMA_FROM_DEVICE) - ret = rd_MEMCPY_read(req); - else - ret = rd_MEMCPY_write(req); - + ret = rd_MEMCPY(req, task->task_data_direction == DMA_FROM_DEVICE); if (ret != 0) return ret; -- 1.7.7.3 >Thanks! > >--nab Sebastian -- To unsubscribe from this list: send the line "unsubscribe target-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
