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_init_bvec(struct bio_vec * bv,struct scatterlist * sg)76 static void nvmet_file_init_bvec(struct bio_vec *bv, struct scatterlist *sg)
77 {
78 bv->bv_page = sg_page(sg);
79 bv->bv_offset = sg->offset;
80 bv->bv_len = sg->length;
81 }
82
nvmet_file_submit_bvec(struct nvmet_req * req,loff_t pos,unsigned long nr_segs,size_t count,int ki_flags)83 static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
84 unsigned long nr_segs, size_t count, int ki_flags)
85 {
86 struct kiocb *iocb = &req->f.iocb;
87 ssize_t (*call_iter)(struct kiocb *iocb, struct iov_iter *iter);
88 struct iov_iter iter;
89 int rw;
90
91 if (req->cmd->rw.opcode == nvme_cmd_write) {
92 if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA))
93 ki_flags |= IOCB_DSYNC;
94 call_iter = req->ns->file->f_op->write_iter;
95 rw = WRITE;
96 } else {
97 call_iter = req->ns->file->f_op->read_iter;
98 rw = READ;
99 }
100
101 iov_iter_bvec(&iter, rw, req->f.bvec, nr_segs, count);
102
103 iocb->ki_pos = pos;
104 iocb->ki_filp = req->ns->file;
105 iocb->ki_flags = ki_flags | iocb->ki_filp->f_iocb_flags;
106
107 return call_iter(iocb, &iter);
108 }
109
nvmet_file_io_done(struct kiocb * iocb,long ret)110 static void nvmet_file_io_done(struct kiocb *iocb, long ret)
111 {
112 struct nvmet_req *req = container_of(iocb, struct nvmet_req, f.iocb);
113 u16 status = NVME_SC_SUCCESS;
114
115 if (req->f.bvec != req->inline_bvec) {
116 if (likely(req->f.mpool_alloc == false))
117 kfree(req->f.bvec);
118 else
119 mempool_free(req->f.bvec, req->ns->bvec_pool);
120 }
121
122 if (unlikely(ret != req->transfer_len))
123 status = errno_to_nvme_status(req, ret);
124 nvmet_req_complete(req, status);
125 }
126
nvmet_file_execute_io(struct nvmet_req * req,int ki_flags)127 static bool nvmet_file_execute_io(struct nvmet_req *req, int ki_flags)
128 {
129 ssize_t nr_bvec = req->sg_cnt;
130 unsigned long bv_cnt = 0;
131 bool is_sync = false;
132 size_t len = 0, total_len = 0;
133 ssize_t ret = 0;
134 loff_t pos;
135 int i;
136 struct scatterlist *sg;
137
138 if (req->f.mpool_alloc && nr_bvec > NVMET_MAX_MPOOL_BVEC)
139 is_sync = true;
140
141 pos = le64_to_cpu(req->cmd->rw.slba) << req->ns->blksize_shift;
142 if (unlikely(pos + req->transfer_len > req->ns->size)) {
143 nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC));
144 return true;
145 }
146
147 memset(&req->f.iocb, 0, sizeof(struct kiocb));
148 for_each_sg(req->sg, sg, req->sg_cnt, i) {
149 nvmet_file_init_bvec(&req->f.bvec[bv_cnt], sg);
150 len += req->f.bvec[bv_cnt].bv_len;
151 total_len += req->f.bvec[bv_cnt].bv_len;
152 bv_cnt++;
153
154 WARN_ON_ONCE((nr_bvec - 1) < 0);
155
156 if (unlikely(is_sync) &&
157 (nr_bvec - 1 == 0 || bv_cnt == NVMET_MAX_MPOOL_BVEC)) {
158 ret = nvmet_file_submit_bvec(req, pos, bv_cnt, len, 0);
159 if (ret < 0)
160 goto complete;
161
162 pos += len;
163 bv_cnt = 0;
164 len = 0;
165 }
166 nr_bvec--;
167 }
168
169 if (WARN_ON_ONCE(total_len != req->transfer_len)) {
170 ret = -EIO;
171 goto complete;
172 }
173
174 if (unlikely(is_sync)) {
175 ret = total_len;
176 goto complete;
177 }
178
179 /*
180 * A NULL ki_complete ask for synchronous execution, which we want
181 * for the IOCB_NOWAIT case.
182 */
183 if (!(ki_flags & IOCB_NOWAIT))
184 req->f.iocb.ki_complete = nvmet_file_io_done;
185
186 ret = nvmet_file_submit_bvec(req, pos, bv_cnt, total_len, ki_flags);
187
188 switch (ret) {
189 case -EIOCBQUEUED:
190 return true;
191 case -EAGAIN:
192 if (WARN_ON_ONCE(!(ki_flags & IOCB_NOWAIT)))
193 goto complete;
194 return false;
195 case -EOPNOTSUPP:
196 /*
197 * For file systems returning error -EOPNOTSUPP, handle
198 * IOCB_NOWAIT error case separately and retry without
199 * IOCB_NOWAIT.
200 */
201 if ((ki_flags & IOCB_NOWAIT))
202 return false;
203 break;
204 }
205
206 complete:
207 nvmet_file_io_done(&req->f.iocb, ret);
208 return true;
209 }
210
nvmet_file_buffered_io_work(struct work_struct * w)211 static void nvmet_file_buffered_io_work(struct work_struct *w)
212 {
213 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
214
215 nvmet_file_execute_io(req, 0);
216 }
217
nvmet_file_submit_buffered_io(struct nvmet_req * req)218 static void nvmet_file_submit_buffered_io(struct nvmet_req *req)
219 {
220 INIT_WORK(&req->f.work, nvmet_file_buffered_io_work);
221 queue_work(buffered_io_wq, &req->f.work);
222 }
223
nvmet_file_execute_rw(struct nvmet_req * req)224 static void nvmet_file_execute_rw(struct nvmet_req *req)
225 {
226 ssize_t nr_bvec = req->sg_cnt;
227
228 if (!nvmet_check_transfer_len(req, nvmet_rw_data_len(req)))
229 return;
230
231 if (!req->sg_cnt || !nr_bvec) {
232 nvmet_req_complete(req, 0);
233 return;
234 }
235
236 if (nr_bvec > NVMET_MAX_INLINE_BIOVEC)
237 req->f.bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec),
238 GFP_KERNEL);
239 else
240 req->f.bvec = req->inline_bvec;
241
242 if (unlikely(!req->f.bvec)) {
243 /* fallback under memory pressure */
244 req->f.bvec = mempool_alloc(req->ns->bvec_pool, GFP_KERNEL);
245 req->f.mpool_alloc = true;
246 } else
247 req->f.mpool_alloc = false;
248
249 if (req->ns->buffered_io) {
250 if (likely(!req->f.mpool_alloc) &&
251 (req->ns->file->f_mode & FMODE_NOWAIT) &&
252 nvmet_file_execute_io(req, IOCB_NOWAIT))
253 return;
254 nvmet_file_submit_buffered_io(req);
255 } else
256 nvmet_file_execute_io(req, 0);
257 }
258
nvmet_file_flush(struct nvmet_req * req)259 u16 nvmet_file_flush(struct nvmet_req *req)
260 {
261 return errno_to_nvme_status(req, vfs_fsync(req->ns->file, 1));
262 }
263
nvmet_file_flush_work(struct work_struct * w)264 static void nvmet_file_flush_work(struct work_struct *w)
265 {
266 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
267
268 nvmet_req_complete(req, nvmet_file_flush(req));
269 }
270
nvmet_file_execute_flush(struct nvmet_req * req)271 static void nvmet_file_execute_flush(struct nvmet_req *req)
272 {
273 if (!nvmet_check_transfer_len(req, 0))
274 return;
275 INIT_WORK(&req->f.work, nvmet_file_flush_work);
276 queue_work(nvmet_wq, &req->f.work);
277 }
278
nvmet_file_execute_discard(struct nvmet_req * req)279 static void nvmet_file_execute_discard(struct nvmet_req *req)
280 {
281 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
282 struct nvme_dsm_range range;
283 loff_t offset, len;
284 u16 status = 0;
285 int ret;
286 int i;
287
288 for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
289 status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
290 sizeof(range));
291 if (status)
292 break;
293
294 offset = le64_to_cpu(range.slba) << req->ns->blksize_shift;
295 len = le32_to_cpu(range.nlb);
296 len <<= req->ns->blksize_shift;
297 if (offset + len > req->ns->size) {
298 req->error_slba = le64_to_cpu(range.slba);
299 status = errno_to_nvme_status(req, -ENOSPC);
300 break;
301 }
302
303 ret = vfs_fallocate(req->ns->file, mode, offset, len);
304 if (ret && ret != -EOPNOTSUPP) {
305 req->error_slba = le64_to_cpu(range.slba);
306 status = errno_to_nvme_status(req, ret);
307 break;
308 }
309 }
310
311 nvmet_req_complete(req, status);
312 }
313
nvmet_file_dsm_work(struct work_struct * w)314 static void nvmet_file_dsm_work(struct work_struct *w)
315 {
316 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
317
318 switch (le32_to_cpu(req->cmd->dsm.attributes)) {
319 case NVME_DSMGMT_AD:
320 nvmet_file_execute_discard(req);
321 return;
322 case NVME_DSMGMT_IDR:
323 case NVME_DSMGMT_IDW:
324 default:
325 /* Not supported yet */
326 nvmet_req_complete(req, 0);
327 return;
328 }
329 }
330
nvmet_file_execute_dsm(struct nvmet_req * req)331 static void nvmet_file_execute_dsm(struct nvmet_req *req)
332 {
333 if (!nvmet_check_data_len_lte(req, nvmet_dsm_len(req)))
334 return;
335 INIT_WORK(&req->f.work, nvmet_file_dsm_work);
336 queue_work(nvmet_wq, &req->f.work);
337 }
338
nvmet_file_write_zeroes_work(struct work_struct * w)339 static void nvmet_file_write_zeroes_work(struct work_struct *w)
340 {
341 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
342 struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes;
343 int mode = FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE;
344 loff_t offset;
345 loff_t len;
346 int ret;
347
348 offset = le64_to_cpu(write_zeroes->slba) << req->ns->blksize_shift;
349 len = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) <<
350 req->ns->blksize_shift);
351
352 if (unlikely(offset + len > req->ns->size)) {
353 nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC));
354 return;
355 }
356
357 ret = vfs_fallocate(req->ns->file, mode, offset, len);
358 nvmet_req_complete(req, ret < 0 ? errno_to_nvme_status(req, ret) : 0);
359 }
360
nvmet_file_execute_write_zeroes(struct nvmet_req * req)361 static void nvmet_file_execute_write_zeroes(struct nvmet_req *req)
362 {
363 if (!nvmet_check_transfer_len(req, 0))
364 return;
365 INIT_WORK(&req->f.work, nvmet_file_write_zeroes_work);
366 queue_work(nvmet_wq, &req->f.work);
367 }
368
nvmet_file_parse_io_cmd(struct nvmet_req * req)369 u16 nvmet_file_parse_io_cmd(struct nvmet_req *req)
370 {
371 switch (req->cmd->common.opcode) {
372 case nvme_cmd_read:
373 case nvme_cmd_write:
374 req->execute = nvmet_file_execute_rw;
375 return 0;
376 case nvme_cmd_flush:
377 req->execute = nvmet_file_execute_flush;
378 return 0;
379 case nvme_cmd_dsm:
380 req->execute = nvmet_file_execute_dsm;
381 return 0;
382 case nvme_cmd_write_zeroes:
383 req->execute = nvmet_file_execute_write_zeroes;
384 return 0;
385 default:
386 return nvmet_report_invalid_opcode(req);
387 }
388 }
389