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 | |
16 | void nvmet_file_ns_revalidate(struct nvmet_ns *ns) |
17 | { |
18 | ns->size = i_size_read(inode: ns->file->f_mapping->host); |
19 | } |
20 | |
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(pool: ns->bvec_pool); |
27 | ns->bvec_pool = NULL; |
28 | fput(ns->file); |
29 | ns->file = NULL; |
30 | } |
31 | } |
32 | |
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(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, alloc_fn: mempool_alloc_slab, |
60 | free_fn: mempool_free_slab, pool_data: 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 | |
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(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 | |
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(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 | |
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, 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 | |
200 | complete: |
201 | nvmet_file_io_done(iocb: &req->f.iocb, ret); |
202 | return true; |
203 | } |
204 | |
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, ki_flags: 0); |
210 | } |
211 | |
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(wq: buffered_io_wq, work: &req->f.work); |
216 | } |
217 | |
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, 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(n: nr_bvec, size: 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(pool: 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 | |
253 | u16 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 | |
258 | static 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 | |
265 | static 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 | |
273 | static 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 | |
308 | static 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 | |
325 | static 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 | |
333 | static 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 | |
355 | static 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 | |
363 | u16 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 | |