1// SPDX-License-Identifier: GPL-2.0
2/*
3 * NVMe Over Fabrics Target File I/O commands implementation.
4 * Copyright (c) 2017-2018 Western Digital Corporation or its
5 * affiliates.
6 */
7#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8#include <linux/uio.h>
9#include <linux/falloc.h>
10#include <linux/file.h>
11#include <linux/fs.h>
12#include "nvmet.h"
13
14#define NVMET_MIN_MPOOL_OBJ 16
15
16void nvmet_file_ns_revalidate(struct nvmet_ns *ns)
17{
18 ns->size = i_size_read(inode: ns->file->f_mapping->host);
19}
20
21void nvmet_file_ns_disable(struct nvmet_ns *ns)
22{
23 if (ns->file) {
24 if (ns->buffered_io)
25 flush_workqueue(buffered_io_wq);
26 mempool_destroy(pool: ns->bvec_pool);
27 ns->bvec_pool = NULL;
28 fput(ns->file);
29 ns->file = NULL;
30 }
31}
32
33int nvmet_file_ns_enable(struct nvmet_ns *ns)
34{
35 int flags = O_RDWR | O_LARGEFILE;
36 int ret = 0;
37
38 if (!ns->buffered_io)
39 flags |= O_DIRECT;
40
41 ns->file = filp_open(ns->device_path, flags, 0);
42 if (IS_ERR(ptr: ns->file)) {
43 ret = PTR_ERR(ptr: ns->file);
44 pr_err("failed to open file %s: (%d)\n",
45 ns->device_path, ret);
46 ns->file = NULL;
47 return ret;
48 }
49
50 nvmet_file_ns_revalidate(ns);
51
52 /*
53 * i_blkbits can be greater than the universally accepted upper bound,
54 * so make sure we export a sane namespace lba_shift.
55 */
56 ns->blksize_shift = min_t(u8,
57 file_inode(ns->file)->i_blkbits, 12);
58
59 ns->bvec_pool = mempool_create(NVMET_MIN_MPOOL_OBJ, mempool_alloc_slab,
60 mempool_free_slab, nvmet_bvec_cache);
61
62 if (!ns->bvec_pool) {
63 ret = -ENOMEM;
64 goto err;
65 }
66
67 return ret;
68err:
69 fput(ns->file);
70 ns->file = NULL;
71 ns->size = 0;
72 ns->blksize_shift = 0;
73 return ret;
74}
75
76static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
77 unsigned long nr_segs, size_t count, int ki_flags)
78{
79 struct kiocb *iocb = &req->f.iocb;
80 ssize_t (*call_iter)(struct kiocb *iocb, struct iov_iter *iter);
81 struct iov_iter iter;
82 int rw;
83
84 if (req->cmd->rw.opcode == nvme_cmd_write) {
85 if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA))
86 ki_flags |= IOCB_DSYNC;
87 call_iter = req->ns->file->f_op->write_iter;
88 rw = ITER_SOURCE;
89 } else {
90 call_iter = req->ns->file->f_op->read_iter;
91 rw = ITER_DEST;
92 }
93
94 iov_iter_bvec(i: &iter, direction: rw, bvec: req->f.bvec, nr_segs, count);
95
96 iocb->ki_pos = pos;
97 iocb->ki_filp = req->ns->file;
98 iocb->ki_flags = ki_flags | iocb->ki_filp->f_iocb_flags;
99
100 return call_iter(iocb, &iter);
101}
102
103static void nvmet_file_io_done(struct kiocb *iocb, long ret)
104{
105 struct nvmet_req *req = container_of(iocb, struct nvmet_req, f.iocb);
106 u16 status = NVME_SC_SUCCESS;
107
108 if (req->f.bvec != req->inline_bvec) {
109 if (likely(req->f.mpool_alloc == false))
110 kfree(objp: req->f.bvec);
111 else
112 mempool_free(element: req->f.bvec, pool: req->ns->bvec_pool);
113 }
114
115 if (unlikely(ret != req->transfer_len))
116 status = errno_to_nvme_status(req, errno: ret);
117 nvmet_req_complete(req, status);
118}
119
120static bool nvmet_file_execute_io(struct nvmet_req *req, int ki_flags)
121{
122 ssize_t nr_bvec = req->sg_cnt;
123 unsigned long bv_cnt = 0;
124 bool is_sync = false;
125 size_t len = 0, total_len = 0;
126 ssize_t ret = 0;
127 loff_t pos;
128 int i;
129 struct scatterlist *sg;
130
131 if (req->f.mpool_alloc && nr_bvec > NVMET_MAX_MPOOL_BVEC)
132 is_sync = true;
133
134 pos = le64_to_cpu(req->cmd->rw.slba) << req->ns->blksize_shift;
135 if (unlikely(pos + req->transfer_len > req->ns->size)) {
136 nvmet_req_complete(req, status: errno_to_nvme_status(req, errno: -ENOSPC));
137 return true;
138 }
139
140 memset(&req->f.iocb, 0, sizeof(struct kiocb));
141 for_each_sg(req->sg, sg, req->sg_cnt, i) {
142 bvec_set_page(bv: &req->f.bvec[bv_cnt], page: sg_page(sg), len: sg->length,
143 offset: sg->offset);
144 len += req->f.bvec[bv_cnt].bv_len;
145 total_len += req->f.bvec[bv_cnt].bv_len;
146 bv_cnt++;
147
148 WARN_ON_ONCE((nr_bvec - 1) < 0);
149
150 if (unlikely(is_sync) &&
151 (nr_bvec - 1 == 0 || bv_cnt == NVMET_MAX_MPOOL_BVEC)) {
152 ret = nvmet_file_submit_bvec(req, pos, nr_segs: bv_cnt, count: len, ki_flags: 0);
153 if (ret < 0)
154 goto complete;
155
156 pos += len;
157 bv_cnt = 0;
158 len = 0;
159 }
160 nr_bvec--;
161 }
162
163 if (WARN_ON_ONCE(total_len != req->transfer_len)) {
164 ret = -EIO;
165 goto complete;
166 }
167
168 if (unlikely(is_sync)) {
169 ret = total_len;
170 goto complete;
171 }
172
173 /*
174 * A NULL ki_complete ask for synchronous execution, which we want
175 * for the IOCB_NOWAIT case.
176 */
177 if (!(ki_flags & IOCB_NOWAIT))
178 req->f.iocb.ki_complete = nvmet_file_io_done;
179
180 ret = nvmet_file_submit_bvec(req, pos, nr_segs: bv_cnt, count: total_len, ki_flags);
181
182 switch (ret) {
183 case -EIOCBQUEUED:
184 return true;
185 case -EAGAIN:
186 if (WARN_ON_ONCE(!(ki_flags & IOCB_NOWAIT)))
187 goto complete;
188 return false;
189 case -EOPNOTSUPP:
190 /*
191 * For file systems returning error -EOPNOTSUPP, handle
192 * IOCB_NOWAIT error case separately and retry without
193 * IOCB_NOWAIT.
194 */
195 if ((ki_flags & IOCB_NOWAIT))
196 return false;
197 break;
198 }
199
200complete:
201 nvmet_file_io_done(iocb: &req->f.iocb, ret);
202 return true;
203}
204
205static void nvmet_file_buffered_io_work(struct work_struct *w)
206{
207 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
208
209 nvmet_file_execute_io(req, ki_flags: 0);
210}
211
212static void nvmet_file_submit_buffered_io(struct nvmet_req *req)
213{
214 INIT_WORK(&req->f.work, nvmet_file_buffered_io_work);
215 queue_work(wq: buffered_io_wq, work: &req->f.work);
216}
217
218static void nvmet_file_execute_rw(struct nvmet_req *req)
219{
220 ssize_t nr_bvec = req->sg_cnt;
221
222 if (!nvmet_check_transfer_len(req, len: nvmet_rw_data_len(req)))
223 return;
224
225 if (!req->sg_cnt || !nr_bvec) {
226 nvmet_req_complete(req, status: 0);
227 return;
228 }
229
230 if (nr_bvec > NVMET_MAX_INLINE_BIOVEC)
231 req->f.bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec),
232 GFP_KERNEL);
233 else
234 req->f.bvec = req->inline_bvec;
235
236 if (unlikely(!req->f.bvec)) {
237 /* fallback under memory pressure */
238 req->f.bvec = mempool_alloc(req->ns->bvec_pool, GFP_KERNEL);
239 req->f.mpool_alloc = true;
240 } else
241 req->f.mpool_alloc = false;
242
243 if (req->ns->buffered_io) {
244 if (likely(!req->f.mpool_alloc) &&
245 (req->ns->file->f_mode & FMODE_NOWAIT) &&
246 nvmet_file_execute_io(req, IOCB_NOWAIT))
247 return;
248 nvmet_file_submit_buffered_io(req);
249 } else
250 nvmet_file_execute_io(req, ki_flags: 0);
251}
252
253u16 nvmet_file_flush(struct nvmet_req *req)
254{
255 return errno_to_nvme_status(req, errno: vfs_fsync(file: req->ns->file, datasync: 1));
256}
257
258static void nvmet_file_flush_work(struct work_struct *w)
259{
260 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
261
262 nvmet_req_complete(req, status: nvmet_file_flush(req));
263}
264
265static void nvmet_file_execute_flush(struct nvmet_req *req)
266{
267 if (!nvmet_check_transfer_len(req, len: 0))
268 return;
269 INIT_WORK(&req->f.work, nvmet_file_flush_work);
270 queue_work(wq: nvmet_wq, work: &req->f.work);
271}
272
273static void nvmet_file_execute_discard(struct nvmet_req *req)
274{
275 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
276 struct nvme_dsm_range range;
277 loff_t offset, len;
278 u16 status = 0;
279 int ret;
280 int i;
281
282 for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
283 status = nvmet_copy_from_sgl(req, off: i * sizeof(range), buf: &range,
284 len: sizeof(range));
285 if (status)
286 break;
287
288 offset = le64_to_cpu(range.slba) << req->ns->blksize_shift;
289 len = le32_to_cpu(range.nlb);
290 len <<= req->ns->blksize_shift;
291 if (offset + len > req->ns->size) {
292 req->error_slba = le64_to_cpu(range.slba);
293 status = errno_to_nvme_status(req, errno: -ENOSPC);
294 break;
295 }
296
297 ret = vfs_fallocate(file: req->ns->file, mode, offset, len);
298 if (ret && ret != -EOPNOTSUPP) {
299 req->error_slba = le64_to_cpu(range.slba);
300 status = errno_to_nvme_status(req, errno: ret);
301 break;
302 }
303 }
304
305 nvmet_req_complete(req, status);
306}
307
308static void nvmet_file_dsm_work(struct work_struct *w)
309{
310 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
311
312 switch (le32_to_cpu(req->cmd->dsm.attributes)) {
313 case NVME_DSMGMT_AD:
314 nvmet_file_execute_discard(req);
315 return;
316 case NVME_DSMGMT_IDR:
317 case NVME_DSMGMT_IDW:
318 default:
319 /* Not supported yet */
320 nvmet_req_complete(req, status: 0);
321 return;
322 }
323}
324
325static void nvmet_file_execute_dsm(struct nvmet_req *req)
326{
327 if (!nvmet_check_data_len_lte(req, data_len: nvmet_dsm_len(req)))
328 return;
329 INIT_WORK(&req->f.work, nvmet_file_dsm_work);
330 queue_work(wq: nvmet_wq, work: &req->f.work);
331}
332
333static void nvmet_file_write_zeroes_work(struct work_struct *w)
334{
335 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
336 struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes;
337 int mode = FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE;
338 loff_t offset;
339 loff_t len;
340 int ret;
341
342 offset = le64_to_cpu(write_zeroes->slba) << req->ns->blksize_shift;
343 len = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) <<
344 req->ns->blksize_shift);
345
346 if (unlikely(offset + len > req->ns->size)) {
347 nvmet_req_complete(req, status: errno_to_nvme_status(req, errno: -ENOSPC));
348 return;
349 }
350
351 ret = vfs_fallocate(file: req->ns->file, mode, offset, len);
352 nvmet_req_complete(req, status: ret < 0 ? errno_to_nvme_status(req, errno: ret) : 0);
353}
354
355static void nvmet_file_execute_write_zeroes(struct nvmet_req *req)
356{
357 if (!nvmet_check_transfer_len(req, len: 0))
358 return;
359 INIT_WORK(&req->f.work, nvmet_file_write_zeroes_work);
360 queue_work(wq: nvmet_wq, work: &req->f.work);
361}
362
363u16 nvmet_file_parse_io_cmd(struct nvmet_req *req)
364{
365 switch (req->cmd->common.opcode) {
366 case nvme_cmd_read:
367 case nvme_cmd_write:
368 req->execute = nvmet_file_execute_rw;
369 return 0;
370 case nvme_cmd_flush:
371 req->execute = nvmet_file_execute_flush;
372 return 0;
373 case nvme_cmd_dsm:
374 req->execute = nvmet_file_execute_dsm;
375 return 0;
376 case nvme_cmd_write_zeroes:
377 req->execute = nvmet_file_execute_write_zeroes;
378 return 0;
379 default:
380 return nvmet_report_invalid_opcode(req);
381 }
382}
383

source code of linux/drivers/nvme/target/io-cmd-file.c