1 /*
2 * NVMe I/O command implementation.
3 * Copyright (c) 2015-2016 HGST, a Western Digital Company.
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 */
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15 #include <linux/blkdev.h>
16 #include <linux/module.h>
17 #include "nvmet.h"
18
nvmet_bio_done(struct bio * bio)19 static void nvmet_bio_done(struct bio *bio)
20 {
21 struct nvmet_req *req = bio->bi_private;
22
23 nvmet_req_complete(req,
24 bio->bi_error ? NVME_SC_INTERNAL | NVME_SC_DNR : 0);
25
26 if (bio != &req->inline_bio)
27 bio_put(bio);
28 }
29
nvmet_rw_len(struct nvmet_req * req)30 static inline u32 nvmet_rw_len(struct nvmet_req *req)
31 {
32 return ((u32)le16_to_cpu(req->cmd->rw.length) + 1) <<
33 req->ns->blksize_shift;
34 }
35
nvmet_inline_bio_init(struct nvmet_req * req)36 static void nvmet_inline_bio_init(struct nvmet_req *req)
37 {
38 struct bio *bio = &req->inline_bio;
39
40 bio_init(bio);
41 bio->bi_max_vecs = NVMET_MAX_INLINE_BIOVEC;
42 bio->bi_io_vec = req->inline_bvec;
43 }
44
nvmet_execute_rw(struct nvmet_req * req)45 static void nvmet_execute_rw(struct nvmet_req *req)
46 {
47 int sg_cnt = req->sg_cnt;
48 struct scatterlist *sg;
49 struct bio *bio;
50 sector_t sector;
51 blk_qc_t cookie;
52 int op, op_flags = 0, i;
53
54 if (!req->sg_cnt) {
55 nvmet_req_complete(req, 0);
56 return;
57 }
58
59 if (req->cmd->rw.opcode == nvme_cmd_write) {
60 op = REQ_OP_WRITE;
61 op_flags = WRITE_ODIRECT;
62 if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA))
63 op_flags |= REQ_FUA;
64 } else {
65 op = REQ_OP_READ;
66 }
67
68 sector = le64_to_cpu(req->cmd->rw.slba);
69 sector <<= (req->ns->blksize_shift - 9);
70
71 nvmet_inline_bio_init(req);
72 bio = &req->inline_bio;
73 bio->bi_bdev = req->ns->bdev;
74 bio->bi_iter.bi_sector = sector;
75 bio->bi_private = req;
76 bio->bi_end_io = nvmet_bio_done;
77 bio_set_op_attrs(bio, op, op_flags);
78
79 for_each_sg(req->sg, sg, req->sg_cnt, i) {
80 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
81 != sg->length) {
82 struct bio *prev = bio;
83
84 bio = bio_alloc(GFP_KERNEL, min(sg_cnt, BIO_MAX_PAGES));
85 bio->bi_bdev = req->ns->bdev;
86 bio->bi_iter.bi_sector = sector;
87 bio_set_op_attrs(bio, op, op_flags);
88
89 bio_chain(bio, prev);
90 cookie = submit_bio(prev);
91 }
92
93 sector += sg->length >> 9;
94 sg_cnt--;
95 }
96
97 cookie = submit_bio(bio);
98
99 blk_poll(bdev_get_queue(req->ns->bdev), cookie);
100 }
101
nvmet_execute_flush(struct nvmet_req * req)102 static void nvmet_execute_flush(struct nvmet_req *req)
103 {
104 struct bio *bio;
105
106 nvmet_inline_bio_init(req);
107 bio = &req->inline_bio;
108
109 bio->bi_bdev = req->ns->bdev;
110 bio->bi_private = req;
111 bio->bi_end_io = nvmet_bio_done;
112 bio_set_op_attrs(bio, REQ_OP_WRITE, WRITE_FLUSH);
113
114 submit_bio(bio);
115 }
116
nvmet_discard_range(struct nvmet_ns * ns,struct nvme_dsm_range * range,struct bio ** bio)117 static u16 nvmet_discard_range(struct nvmet_ns *ns,
118 struct nvme_dsm_range *range, struct bio **bio)
119 {
120 if (__blkdev_issue_discard(ns->bdev,
121 le64_to_cpu(range->slba) << (ns->blksize_shift - 9),
122 le32_to_cpu(range->nlb) << (ns->blksize_shift - 9),
123 GFP_KERNEL, 0, bio))
124 return NVME_SC_INTERNAL | NVME_SC_DNR;
125 return 0;
126 }
127
nvmet_execute_discard(struct nvmet_req * req)128 static void nvmet_execute_discard(struct nvmet_req *req)
129 {
130 struct nvme_dsm_range range;
131 struct bio *bio = NULL;
132 int i;
133 u16 status;
134
135 for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
136 status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
137 sizeof(range));
138 if (status)
139 break;
140
141 status = nvmet_discard_range(req->ns, &range, &bio);
142 if (status)
143 break;
144 }
145
146 if (bio) {
147 bio->bi_private = req;
148 bio->bi_end_io = nvmet_bio_done;
149 if (status) {
150 bio->bi_error = -EIO;
151 bio_endio(bio);
152 } else {
153 submit_bio(bio);
154 }
155 } else {
156 nvmet_req_complete(req, status);
157 }
158 }
159
nvmet_execute_dsm(struct nvmet_req * req)160 static void nvmet_execute_dsm(struct nvmet_req *req)
161 {
162 switch (le32_to_cpu(req->cmd->dsm.attributes)) {
163 case NVME_DSMGMT_AD:
164 nvmet_execute_discard(req);
165 return;
166 case NVME_DSMGMT_IDR:
167 case NVME_DSMGMT_IDW:
168 default:
169 /* Not supported yet */
170 nvmet_req_complete(req, 0);
171 return;
172 }
173 }
174
nvmet_parse_io_cmd(struct nvmet_req * req)175 int nvmet_parse_io_cmd(struct nvmet_req *req)
176 {
177 struct nvme_command *cmd = req->cmd;
178
179 if (unlikely(!(req->sq->ctrl->cc & NVME_CC_ENABLE))) {
180 pr_err("nvmet: got io cmd %d while CC.EN == 0\n",
181 cmd->common.opcode);
182 req->ns = NULL;
183 return NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
184 }
185
186 if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) {
187 pr_err("nvmet: got io cmd %d while CSTS.RDY == 0\n",
188 cmd->common.opcode);
189 req->ns = NULL;
190 return NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
191 }
192
193 req->ns = nvmet_find_namespace(req->sq->ctrl, cmd->rw.nsid);
194 if (!req->ns)
195 return NVME_SC_INVALID_NS | NVME_SC_DNR;
196
197 switch (cmd->common.opcode) {
198 case nvme_cmd_read:
199 case nvme_cmd_write:
200 req->execute = nvmet_execute_rw;
201 req->data_len = nvmet_rw_len(req);
202 return 0;
203 case nvme_cmd_flush:
204 req->execute = nvmet_execute_flush;
205 req->data_len = 0;
206 return 0;
207 case nvme_cmd_dsm:
208 req->execute = nvmet_execute_dsm;
209 req->data_len = le32_to_cpu(cmd->dsm.nr + 1) *
210 sizeof(struct nvme_dsm_range);
211 return 0;
212 default:
213 pr_err("nvmet: unhandled cmd %d\n", cmd->common.opcode);
214 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
215 }
216 }
217