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
nvmet_file_ns_revalidate(struct nvmet_ns * ns)16 void nvmet_file_ns_revalidate(struct nvmet_ns *ns)
17 {
18 ns->size = i_size_read(ns->file->f_mapping->host);
19 }
20
nvmet_file_ns_disable(struct nvmet_ns * ns)21 void 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(ns->bvec_pool);
27 ns->bvec_pool = NULL;
28 fput(ns->file);
29 ns->file = NULL;
30 }
31 }
32
nvmet_file_ns_enable(struct nvmet_ns * ns)33 int 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(ns->file)) {
43 ret = PTR_ERR(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;
68 err:
69 fput(ns->file);
70 ns->file = NULL;
71 ns->size = 0;
72 ns->blksize_shift = 0;
73 return ret;
74 }
75
nvmet_file_submit_bvec(struct nvmet_req * req,loff_t pos,unsigned long nr_segs,size_t count,int ki_flags)76 static 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(&iter, rw, 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
nvmet_file_io_done(struct kiocb * iocb,long ret)103 static 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(req->f.bvec);
111 else
112 mempool_free(req->f.bvec, req->ns->bvec_pool);
113 }
114
115 if (unlikely(ret != req->transfer_len))
116 status = errno_to_nvme_status(req, ret);
117 nvmet_req_complete(req, status);
118 }
119
nvmet_file_execute_io(struct nvmet_req * req,int ki_flags)120 static 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, errno_to_nvme_status(req, -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(&req->f.bvec[bv_cnt], sg_page(sg), sg->length,
143 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, bv_cnt, len, 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, bv_cnt, 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
200 complete:
201 nvmet_file_io_done(&req->f.iocb, ret);
202 return true;
203 }
204
nvmet_file_buffered_io_work(struct work_struct * w)205 static 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, 0);
210 }
211
nvmet_file_submit_buffered_io(struct nvmet_req * req)212 static 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(buffered_io_wq, &req->f.work);
216 }
217
nvmet_file_execute_rw(struct nvmet_req * req)218 static 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, nvmet_rw_data_len(req)))
223 return;
224
225 if (!req->sg_cnt || !nr_bvec) {
226 nvmet_req_complete(req, 0);
227 return;
228 }
229
230 if (nr_bvec > NVMET_MAX_INLINE_BIOVEC)
231 req->f.bvec = kmalloc_objs(struct bio_vec, nr_bvec);
232 else
233 req->f.bvec = req->inline_bvec;
234
235 if (unlikely(!req->f.bvec)) {
236 /* fallback under memory pressure */
237 req->f.bvec = mempool_alloc(req->ns->bvec_pool, GFP_KERNEL);
238 req->f.mpool_alloc = true;
239 } else
240 req->f.mpool_alloc = false;
241
242 if (req->ns->buffered_io) {
243 if (likely(!req->f.mpool_alloc) &&
244 (req->ns->file->f_mode & FMODE_NOWAIT) &&
245 nvmet_file_execute_io(req, IOCB_NOWAIT))
246 return;
247 nvmet_file_submit_buffered_io(req);
248 } else
249 nvmet_file_execute_io(req, 0);
250 }
251
nvmet_file_flush(struct nvmet_req * req)252 u16 nvmet_file_flush(struct nvmet_req *req)
253 {
254 return errno_to_nvme_status(req, vfs_fsync(req->ns->file, 1));
255 }
256
nvmet_file_flush_work(struct work_struct * w)257 static void nvmet_file_flush_work(struct work_struct *w)
258 {
259 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
260
261 nvmet_req_complete(req, nvmet_file_flush(req));
262 }
263
nvmet_file_execute_flush(struct nvmet_req * req)264 static void nvmet_file_execute_flush(struct nvmet_req *req)
265 {
266 if (!nvmet_check_transfer_len(req, 0))
267 return;
268 INIT_WORK(&req->f.work, nvmet_file_flush_work);
269 queue_work(nvmet_wq, &req->f.work);
270 }
271
nvmet_file_execute_discard(struct nvmet_req * req)272 static void nvmet_file_execute_discard(struct nvmet_req *req)
273 {
274 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
275 struct nvme_dsm_range range;
276 loff_t offset, len;
277 u16 status = 0;
278 int ret;
279 int i;
280
281 for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
282 status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
283 sizeof(range));
284 if (status)
285 break;
286
287 offset = le64_to_cpu(range.slba) << req->ns->blksize_shift;
288 len = le32_to_cpu(range.nlb);
289 len <<= req->ns->blksize_shift;
290 if (offset + len > req->ns->size) {
291 req->error_slba = le64_to_cpu(range.slba);
292 status = errno_to_nvme_status(req, -ENOSPC);
293 break;
294 }
295
296 ret = vfs_fallocate(req->ns->file, mode, offset, len);
297 if (ret && ret != -EOPNOTSUPP) {
298 req->error_slba = le64_to_cpu(range.slba);
299 status = errno_to_nvme_status(req, ret);
300 break;
301 }
302 }
303
304 nvmet_req_complete(req, status);
305 }
306
nvmet_file_dsm_work(struct work_struct * w)307 static void nvmet_file_dsm_work(struct work_struct *w)
308 {
309 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
310
311 switch (le32_to_cpu(req->cmd->dsm.attributes)) {
312 case NVME_DSMGMT_AD:
313 nvmet_file_execute_discard(req);
314 return;
315 case NVME_DSMGMT_IDR:
316 case NVME_DSMGMT_IDW:
317 default:
318 /* Not supported yet */
319 nvmet_req_complete(req, 0);
320 return;
321 }
322 }
323
nvmet_file_execute_dsm(struct nvmet_req * req)324 static void nvmet_file_execute_dsm(struct nvmet_req *req)
325 {
326 if (!nvmet_check_data_len_lte(req, nvmet_dsm_len(req)))
327 return;
328 INIT_WORK(&req->f.work, nvmet_file_dsm_work);
329 queue_work(nvmet_wq, &req->f.work);
330 }
331
nvmet_file_write_zeroes_work(struct work_struct * w)332 static void nvmet_file_write_zeroes_work(struct work_struct *w)
333 {
334 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
335 struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes;
336 int mode = FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE;
337 loff_t offset;
338 loff_t len;
339 int ret;
340
341 offset = le64_to_cpu(write_zeroes->slba) << req->ns->blksize_shift;
342 len = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) <<
343 req->ns->blksize_shift);
344
345 if (unlikely(offset + len > req->ns->size)) {
346 nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC));
347 return;
348 }
349
350 ret = vfs_fallocate(req->ns->file, mode, offset, len);
351 nvmet_req_complete(req, ret < 0 ? errno_to_nvme_status(req, ret) : 0);
352 }
353
nvmet_file_execute_write_zeroes(struct nvmet_req * req)354 static void nvmet_file_execute_write_zeroes(struct nvmet_req *req)
355 {
356 if (!nvmet_check_transfer_len(req, 0))
357 return;
358 INIT_WORK(&req->f.work, nvmet_file_write_zeroes_work);
359 queue_work(nvmet_wq, &req->f.work);
360 }
361
nvmet_file_parse_io_cmd(struct nvmet_req * req)362 u16 nvmet_file_parse_io_cmd(struct nvmet_req *req)
363 {
364 switch (req->cmd->common.opcode) {
365 case nvme_cmd_read:
366 case nvme_cmd_write:
367 req->execute = nvmet_file_execute_rw;
368 return 0;
369 case nvme_cmd_flush:
370 req->execute = nvmet_file_execute_flush;
371 return 0;
372 case nvme_cmd_dsm:
373 req->execute = nvmet_file_execute_dsm;
374 return 0;
375 case nvme_cmd_write_zeroes:
376 req->execute = nvmet_file_execute_write_zeroes;
377 return 0;
378 default:
379 return nvmet_report_invalid_opcode(req);
380 }
381 }
382