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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/mm/page_io.c | |
4 | * | |
5 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds | |
6 | * | |
7 | * Swap reorganised 29.12.95, | |
8 | * Asynchronous swapping added 30.12.95. Stephen Tweedie | |
9 | * Removed race in async swapping. 14.4.1996. Bruno Haible | |
10 | * Add swap of shared pages through the page cache. 20.2.1998. Stephen Tweedie | |
11 | * Always use brw_page, life becomes simpler. 12 May 1998 Eric Biederman | |
12 | */ | |
13 | ||
14 | #include <linux/mm.h> | |
15 | #include <linux/kernel_stat.h> | |
5a0e3ad6 | 16 | #include <linux/gfp.h> |
1da177e4 LT |
17 | #include <linux/pagemap.h> |
18 | #include <linux/swap.h> | |
19 | #include <linux/bio.h> | |
20 | #include <linux/swapops.h> | |
62c230bc | 21 | #include <linux/buffer_head.h> |
1da177e4 | 22 | #include <linux/writeback.h> |
38b5faf4 | 23 | #include <linux/frontswap.h> |
b430e9d1 | 24 | #include <linux/blkdev.h> |
93779069 | 25 | #include <linux/psi.h> |
e2e40f2c | 26 | #include <linux/uio.h> |
b0ba2d0f | 27 | #include <linux/sched/task.h> |
a3d5dc90 | 28 | #include <linux/delayacct.h> |
014bb1de | 29 | #include "swap.h" |
1da177e4 | 30 | |
4246a0b6 | 31 | void end_swap_bio_write(struct bio *bio) |
1da177e4 | 32 | { |
263663cd | 33 | struct page *page = bio_first_page_all(bio); |
1da177e4 | 34 | |
4e4cbee9 | 35 | if (bio->bi_status) { |
1da177e4 | 36 | SetPageError(page); |
6ddab3b9 PZ |
37 | /* |
38 | * We failed to write the page out to swap-space. | |
39 | * Re-dirty the page in order to avoid it being reclaimed. | |
40 | * Also print a dire warning that things will go BAD (tm) | |
41 | * very quickly. | |
42 | * | |
575ced1c | 43 | * Also clear PG_reclaim to avoid folio_rotate_reclaimable() |
6ddab3b9 PZ |
44 | */ |
45 | set_page_dirty(page); | |
25eaab43 GD |
46 | pr_alert_ratelimited("Write-error on swap-device (%u:%u:%llu)\n", |
47 | MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)), | |
48 | (unsigned long long)bio->bi_iter.bi_sector); | |
6ddab3b9 PZ |
49 | ClearPageReclaim(page); |
50 | } | |
1da177e4 LT |
51 | end_page_writeback(page); |
52 | bio_put(bio); | |
1da177e4 LT |
53 | } |
54 | ||
4246a0b6 | 55 | static void end_swap_bio_read(struct bio *bio) |
1da177e4 | 56 | { |
263663cd | 57 | struct page *page = bio_first_page_all(bio); |
23955622 | 58 | struct task_struct *waiter = bio->bi_private; |
1da177e4 | 59 | |
4e4cbee9 | 60 | if (bio->bi_status) { |
1da177e4 LT |
61 | SetPageError(page); |
62 | ClearPageUptodate(page); | |
25eaab43 GD |
63 | pr_alert_ratelimited("Read-error on swap-device (%u:%u:%llu)\n", |
64 | MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)), | |
65 | (unsigned long long)bio->bi_iter.bi_sector); | |
b430e9d1 | 66 | goto out; |
1da177e4 | 67 | } |
b430e9d1 MK |
68 | |
69 | SetPageUptodate(page); | |
b430e9d1 | 70 | out: |
1da177e4 | 71 | unlock_page(page); |
23955622 | 72 | WRITE_ONCE(bio->bi_private, NULL); |
1da177e4 | 73 | bio_put(bio); |
87518530 ON |
74 | if (waiter) { |
75 | blk_wake_io_task(waiter); | |
76 | put_task_struct(waiter); | |
77 | } | |
1da177e4 LT |
78 | } |
79 | ||
a509bc1a MG |
80 | int generic_swapfile_activate(struct swap_info_struct *sis, |
81 | struct file *swap_file, | |
82 | sector_t *span) | |
83 | { | |
84 | struct address_space *mapping = swap_file->f_mapping; | |
85 | struct inode *inode = mapping->host; | |
86 | unsigned blocks_per_page; | |
87 | unsigned long page_no; | |
88 | unsigned blkbits; | |
89 | sector_t probe_block; | |
90 | sector_t last_block; | |
91 | sector_t lowest_block = -1; | |
92 | sector_t highest_block = 0; | |
93 | int nr_extents = 0; | |
94 | int ret; | |
95 | ||
96 | blkbits = inode->i_blkbits; | |
97 | blocks_per_page = PAGE_SIZE >> blkbits; | |
98 | ||
99 | /* | |
4efaceb1 | 100 | * Map all the blocks into the extent tree. This code doesn't try |
a509bc1a MG |
101 | * to be very smart. |
102 | */ | |
103 | probe_block = 0; | |
104 | page_no = 0; | |
105 | last_block = i_size_read(inode) >> blkbits; | |
106 | while ((probe_block + blocks_per_page) <= last_block && | |
107 | page_no < sis->max) { | |
108 | unsigned block_in_page; | |
109 | sector_t first_block; | |
110 | ||
7e4411bf MP |
111 | cond_resched(); |
112 | ||
30460e1e CM |
113 | first_block = probe_block; |
114 | ret = bmap(inode, &first_block); | |
115 | if (ret || !first_block) | |
a509bc1a MG |
116 | goto bad_bmap; |
117 | ||
118 | /* | |
119 | * It must be PAGE_SIZE aligned on-disk | |
120 | */ | |
121 | if (first_block & (blocks_per_page - 1)) { | |
122 | probe_block++; | |
123 | goto reprobe; | |
124 | } | |
125 | ||
126 | for (block_in_page = 1; block_in_page < blocks_per_page; | |
127 | block_in_page++) { | |
128 | sector_t block; | |
129 | ||
30460e1e CM |
130 | block = probe_block + block_in_page; |
131 | ret = bmap(inode, &block); | |
132 | if (ret || !block) | |
a509bc1a | 133 | goto bad_bmap; |
30460e1e | 134 | |
a509bc1a MG |
135 | if (block != first_block + block_in_page) { |
136 | /* Discontiguity */ | |
137 | probe_block++; | |
138 | goto reprobe; | |
139 | } | |
140 | } | |
141 | ||
142 | first_block >>= (PAGE_SHIFT - blkbits); | |
143 | if (page_no) { /* exclude the header page */ | |
144 | if (first_block < lowest_block) | |
145 | lowest_block = first_block; | |
146 | if (first_block > highest_block) | |
147 | highest_block = first_block; | |
148 | } | |
149 | ||
150 | /* | |
151 | * We found a PAGE_SIZE-length, PAGE_SIZE-aligned run of blocks | |
152 | */ | |
153 | ret = add_swap_extent(sis, page_no, 1, first_block); | |
154 | if (ret < 0) | |
155 | goto out; | |
156 | nr_extents += ret; | |
157 | page_no++; | |
158 | probe_block += blocks_per_page; | |
159 | reprobe: | |
160 | continue; | |
161 | } | |
162 | ret = nr_extents; | |
163 | *span = 1 + highest_block - lowest_block; | |
164 | if (page_no == 0) | |
165 | page_no = 1; /* force Empty message */ | |
166 | sis->max = page_no; | |
167 | sis->pages = page_no - 1; | |
168 | sis->highest_bit = page_no - 1; | |
169 | out: | |
170 | return ret; | |
171 | bad_bmap: | |
1170532b | 172 | pr_err("swapon: swapfile has holes\n"); |
a509bc1a MG |
173 | ret = -EINVAL; |
174 | goto out; | |
175 | } | |
176 | ||
1da177e4 LT |
177 | /* |
178 | * We may have stale swap cache pages in memory: notice | |
179 | * them here and get rid of the unnecessary final write. | |
180 | */ | |
181 | int swap_writepage(struct page *page, struct writeback_control *wbc) | |
182 | { | |
2f772e6c | 183 | int ret = 0; |
1da177e4 | 184 | |
a2c43eed | 185 | if (try_to_free_swap(page)) { |
1da177e4 LT |
186 | unlock_page(page); |
187 | goto out; | |
188 | } | |
8a84802e SP |
189 | /* |
190 | * Arch code may have to preserve more data than just the page | |
191 | * contents, e.g. memory tags. | |
192 | */ | |
193 | ret = arch_prepare_to_swap(page); | |
194 | if (ret) { | |
195 | set_page_dirty(page); | |
196 | unlock_page(page); | |
197 | goto out; | |
198 | } | |
165c8aed | 199 | if (frontswap_store(page) == 0) { |
38b5faf4 DM |
200 | set_page_writeback(page); |
201 | unlock_page(page); | |
202 | end_page_writeback(page); | |
203 | goto out; | |
204 | } | |
1eec6702 | 205 | ret = __swap_writepage(page, wbc, end_swap_bio_write); |
2f772e6c SJ |
206 | out: |
207 | return ret; | |
208 | } | |
209 | ||
225311a4 HY |
210 | static inline void count_swpout_vm_event(struct page *page) |
211 | { | |
212 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
213 | if (unlikely(PageTransHuge(page))) | |
214 | count_vm_event(THP_SWPOUT); | |
215 | #endif | |
6c357848 | 216 | count_vm_events(PSWPOUT, thp_nr_pages(page)); |
225311a4 HY |
217 | } |
218 | ||
a18b9b15 CH |
219 | #if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP) |
220 | static void bio_associate_blkg_from_page(struct bio *bio, struct page *page) | |
221 | { | |
222 | struct cgroup_subsys_state *css; | |
bcfe06bf | 223 | struct mem_cgroup *memcg; |
a18b9b15 | 224 | |
bcfe06bf RG |
225 | memcg = page_memcg(page); |
226 | if (!memcg) | |
a18b9b15 CH |
227 | return; |
228 | ||
229 | rcu_read_lock(); | |
bcfe06bf | 230 | css = cgroup_e_css(memcg->css.cgroup, &io_cgrp_subsys); |
a18b9b15 CH |
231 | bio_associate_blkg_from_css(bio, css); |
232 | rcu_read_unlock(); | |
233 | } | |
234 | #else | |
235 | #define bio_associate_blkg_from_page(bio, page) do { } while (0) | |
236 | #endif /* CONFIG_MEMCG && CONFIG_BLK_CGROUP */ | |
237 | ||
e1209d3a N |
238 | struct swap_iocb { |
239 | struct kiocb iocb; | |
5169b844 N |
240 | struct bio_vec bvec[SWAP_CLUSTER_MAX]; |
241 | int pages; | |
e1209d3a N |
242 | }; |
243 | static mempool_t *sio_pool; | |
244 | ||
245 | int sio_pool_init(void) | |
246 | { | |
247 | if (!sio_pool) { | |
248 | mempool_t *pool = mempool_create_kmalloc_pool( | |
249 | SWAP_CLUSTER_MAX, sizeof(struct swap_iocb)); | |
250 | if (cmpxchg(&sio_pool, NULL, pool)) | |
251 | mempool_destroy(pool); | |
252 | } | |
253 | if (!sio_pool) | |
254 | return -ENOMEM; | |
255 | return 0; | |
256 | } | |
257 | ||
7eadabc0 N |
258 | static void sio_write_complete(struct kiocb *iocb, long ret) |
259 | { | |
260 | struct swap_iocb *sio = container_of(iocb, struct swap_iocb, iocb); | |
5169b844 | 261 | struct page *page = sio->bvec[0].bv_page; |
2282679f | 262 | int p; |
7eadabc0 | 263 | |
2282679f | 264 | if (ret != PAGE_SIZE * sio->pages) { |
7eadabc0 N |
265 | /* |
266 | * In the case of swap-over-nfs, this can be a | |
267 | * temporary failure if the system has limited | |
268 | * memory for allocating transmit buffers. | |
269 | * Mark the page dirty and avoid | |
270 | * folio_rotate_reclaimable but rate-limit the | |
271 | * messages but do not flag PageError like | |
272 | * the normal direct-to-bio case as it could | |
273 | * be temporary. | |
274 | */ | |
7eadabc0 N |
275 | pr_err_ratelimited("Write error %ld on dio swapfile (%llu)\n", |
276 | ret, page_file_offset(page)); | |
2282679f N |
277 | for (p = 0; p < sio->pages; p++) { |
278 | page = sio->bvec[p].bv_page; | |
279 | set_page_dirty(page); | |
280 | ClearPageReclaim(page); | |
281 | } | |
7eadabc0 | 282 | } else |
2282679f N |
283 | count_vm_events(PSWPOUT, sio->pages); |
284 | ||
285 | for (p = 0; p < sio->pages; p++) | |
286 | end_page_writeback(sio->bvec[p].bv_page); | |
287 | ||
7eadabc0 N |
288 | mempool_free(sio, sio_pool); |
289 | } | |
290 | ||
291 | static int swap_writepage_fs(struct page *page, struct writeback_control *wbc) | |
292 | { | |
2282679f | 293 | struct swap_iocb *sio = NULL; |
7eadabc0 N |
294 | struct swap_info_struct *sis = page_swap_info(page); |
295 | struct file *swap_file = sis->swap_file; | |
2282679f | 296 | loff_t pos = page_file_offset(page); |
7eadabc0 N |
297 | |
298 | set_page_writeback(page); | |
299 | unlock_page(page); | |
2282679f N |
300 | if (wbc->swap_plug) |
301 | sio = *wbc->swap_plug; | |
302 | if (sio) { | |
303 | if (sio->iocb.ki_filp != swap_file || | |
304 | sio->iocb.ki_pos + sio->pages * PAGE_SIZE != pos) { | |
305 | swap_write_unplug(sio); | |
306 | sio = NULL; | |
307 | } | |
308 | } | |
309 | if (!sio) { | |
310 | sio = mempool_alloc(sio_pool, GFP_NOIO); | |
311 | init_sync_kiocb(&sio->iocb, swap_file); | |
312 | sio->iocb.ki_complete = sio_write_complete; | |
313 | sio->iocb.ki_pos = pos; | |
314 | sio->pages = 0; | |
315 | } | |
316 | sio->bvec[sio->pages].bv_page = page; | |
317 | sio->bvec[sio->pages].bv_len = PAGE_SIZE; | |
318 | sio->bvec[sio->pages].bv_offset = 0; | |
319 | sio->pages += 1; | |
320 | if (sio->pages == ARRAY_SIZE(sio->bvec) || !wbc->swap_plug) { | |
321 | swap_write_unplug(sio); | |
322 | sio = NULL; | |
323 | } | |
324 | if (wbc->swap_plug) | |
325 | *wbc->swap_plug = sio; | |
326 | ||
327 | return 0; | |
7eadabc0 N |
328 | } |
329 | ||
1eec6702 | 330 | int __swap_writepage(struct page *page, struct writeback_control *wbc, |
2282679f | 331 | bio_end_io_t end_write_func) |
2f772e6c SJ |
332 | { |
333 | struct bio *bio; | |
4e49ea4a | 334 | int ret; |
2f772e6c | 335 | struct swap_info_struct *sis = page_swap_info(page); |
62c230bc | 336 | |
cc30c5d6 | 337 | VM_BUG_ON_PAGE(!PageSwapCache(page), page); |
7eadabc0 N |
338 | /* |
339 | * ->flags can be updated non-atomicially (scan_swap_map_slots), | |
340 | * but that will never affect SWP_FS_OPS, so the data_race | |
341 | * is safe. | |
342 | */ | |
343 | if (data_race(sis->flags & SWP_FS_OPS)) | |
344 | return swap_writepage_fs(page, wbc); | |
62c230bc | 345 | |
dd6bd0d9 MW |
346 | ret = bdev_write_page(sis->bdev, swap_page_sector(page), page, wbc); |
347 | if (!ret) { | |
225311a4 | 348 | count_swpout_vm_event(page); |
dd6bd0d9 MW |
349 | return 0; |
350 | } | |
351 | ||
07888c66 CH |
352 | bio = bio_alloc(sis->bdev, 1, |
353 | REQ_OP_WRITE | REQ_SWAP | wbc_to_write_flags(wbc), | |
354 | GFP_NOIO); | |
48d15436 | 355 | bio->bi_iter.bi_sector = swap_page_sector(page); |
48d15436 CH |
356 | bio->bi_end_io = end_write_func; |
357 | bio_add_page(bio, page, thp_size(page), 0); | |
358 | ||
6a7f6d86 | 359 | bio_associate_blkg_from_page(bio, page); |
225311a4 | 360 | count_swpout_vm_event(page); |
1da177e4 LT |
361 | set_page_writeback(page); |
362 | unlock_page(page); | |
4e49ea4a | 363 | submit_bio(bio); |
548d9782 ML |
364 | |
365 | return 0; | |
1da177e4 LT |
366 | } |
367 | ||
2282679f N |
368 | void swap_write_unplug(struct swap_iocb *sio) |
369 | { | |
370 | struct iov_iter from; | |
371 | struct address_space *mapping = sio->iocb.ki_filp->f_mapping; | |
372 | int ret; | |
373 | ||
374 | iov_iter_bvec(&from, WRITE, sio->bvec, sio->pages, | |
375 | PAGE_SIZE * sio->pages); | |
376 | ret = mapping->a_ops->swap_rw(&sio->iocb, &from); | |
377 | if (ret != -EIOCBQUEUED) | |
378 | sio_write_complete(&sio->iocb, ret); | |
379 | } | |
380 | ||
e1209d3a N |
381 | static void sio_read_complete(struct kiocb *iocb, long ret) |
382 | { | |
383 | struct swap_iocb *sio = container_of(iocb, struct swap_iocb, iocb); | |
5169b844 | 384 | int p; |
e1209d3a | 385 | |
5169b844 N |
386 | if (ret == PAGE_SIZE * sio->pages) { |
387 | for (p = 0; p < sio->pages; p++) { | |
388 | struct page *page = sio->bvec[p].bv_page; | |
389 | ||
390 | SetPageUptodate(page); | |
391 | unlock_page(page); | |
392 | } | |
393 | count_vm_events(PSWPIN, sio->pages); | |
e1209d3a | 394 | } else { |
5169b844 N |
395 | for (p = 0; p < sio->pages; p++) { |
396 | struct page *page = sio->bvec[p].bv_page; | |
397 | ||
398 | SetPageError(page); | |
399 | ClearPageUptodate(page); | |
400 | unlock_page(page); | |
401 | } | |
402 | pr_alert_ratelimited("Read-error on swap-device\n"); | |
e1209d3a | 403 | } |
e1209d3a N |
404 | mempool_free(sio, sio_pool); |
405 | } | |
406 | ||
5169b844 N |
407 | static void swap_readpage_fs(struct page *page, |
408 | struct swap_iocb **plug) | |
e1209d3a N |
409 | { |
410 | struct swap_info_struct *sis = page_swap_info(page); | |
5169b844 | 411 | struct swap_iocb *sio = NULL; |
e1209d3a | 412 | loff_t pos = page_file_offset(page); |
e1209d3a | 413 | |
5169b844 N |
414 | if (plug) |
415 | sio = *plug; | |
416 | if (sio) { | |
417 | if (sio->iocb.ki_filp != sis->swap_file || | |
418 | sio->iocb.ki_pos + sio->pages * PAGE_SIZE != pos) { | |
419 | swap_read_unplug(sio); | |
420 | sio = NULL; | |
421 | } | |
422 | } | |
423 | if (!sio) { | |
424 | sio = mempool_alloc(sio_pool, GFP_KERNEL); | |
425 | init_sync_kiocb(&sio->iocb, sis->swap_file); | |
426 | sio->iocb.ki_pos = pos; | |
427 | sio->iocb.ki_complete = sio_read_complete; | |
428 | sio->pages = 0; | |
429 | } | |
430 | sio->bvec[sio->pages].bv_page = page; | |
431 | sio->bvec[sio->pages].bv_len = PAGE_SIZE; | |
432 | sio->bvec[sio->pages].bv_offset = 0; | |
433 | sio->pages += 1; | |
434 | if (sio->pages == ARRAY_SIZE(sio->bvec) || !plug) { | |
435 | swap_read_unplug(sio); | |
436 | sio = NULL; | |
437 | } | |
438 | if (plug) | |
439 | *plug = sio; | |
e1209d3a N |
440 | } |
441 | ||
5169b844 N |
442 | int swap_readpage(struct page *page, bool synchronous, |
443 | struct swap_iocb **plug) | |
1da177e4 LT |
444 | { |
445 | struct bio *bio; | |
446 | int ret = 0; | |
62c230bc | 447 | struct swap_info_struct *sis = page_swap_info(page); |
d8c47cc7 | 448 | bool workingset = PageWorkingset(page); |
93779069 | 449 | unsigned long pflags; |
1da177e4 | 450 | |
0bcac06f | 451 | VM_BUG_ON_PAGE(!PageSwapCache(page) && !synchronous, page); |
309381fe SL |
452 | VM_BUG_ON_PAGE(!PageLocked(page), page); |
453 | VM_BUG_ON_PAGE(PageUptodate(page), page); | |
93779069 MK |
454 | |
455 | /* | |
456 | * Count submission time as memory stall. When the device is congested, | |
457 | * or the submitting cgroup IO-throttled, submission can be a | |
458 | * significant part of overall IO time. | |
459 | */ | |
d8c47cc7 JW |
460 | if (workingset) |
461 | psi_memstall_enter(&pflags); | |
a3d5dc90 | 462 | delayacct_swapin_start(); |
93779069 | 463 | |
165c8aed | 464 | if (frontswap_load(page) == 0) { |
38b5faf4 DM |
465 | SetPageUptodate(page); |
466 | unlock_page(page); | |
467 | goto out; | |
468 | } | |
62c230bc | 469 | |
32646315 | 470 | if (data_race(sis->flags & SWP_FS_OPS)) { |
5169b844 | 471 | swap_readpage_fs(page, plug); |
93779069 | 472 | goto out; |
62c230bc MG |
473 | } |
474 | ||
5115db10 CH |
475 | if (sis->flags & SWP_SYNCHRONOUS_IO) { |
476 | ret = bdev_read_page(sis->bdev, swap_page_sector(page), page); | |
477 | if (!ret) { | |
5115db10 CH |
478 | count_vm_event(PSWPIN); |
479 | goto out; | |
480 | } | |
dd6bd0d9 MW |
481 | } |
482 | ||
483 | ret = 0; | |
07888c66 | 484 | bio = bio_alloc(sis->bdev, 1, REQ_OP_READ, GFP_KERNEL); |
48d15436 CH |
485 | bio->bi_iter.bi_sector = swap_page_sector(page); |
486 | bio->bi_end_io = end_swap_bio_read; | |
487 | bio_add_page(bio, page, thp_size(page), 0); | |
b0ba2d0f TH |
488 | /* |
489 | * Keep this task valid during swap readpage because the oom killer may | |
490 | * attempt to access it in the page fault retry time check. | |
491 | */ | |
87518530 | 492 | if (synchronous) { |
6ce913fe | 493 | bio->bi_opf |= REQ_POLLED; |
87518530 ON |
494 | get_task_struct(current); |
495 | bio->bi_private = current; | |
496 | } | |
f8891e5e | 497 | count_vm_event(PSWPIN); |
23955622 | 498 | bio_get(bio); |
3e08773c | 499 | submit_bio(bio); |
0bcac06f | 500 | while (synchronous) { |
1ac5cd49 | 501 | set_current_state(TASK_UNINTERRUPTIBLE); |
23955622 SL |
502 | if (!READ_ONCE(bio->bi_private)) |
503 | break; | |
504 | ||
5a72e899 | 505 | if (!bio_poll(bio, NULL, 0)) |
0f190a7a | 506 | blk_io_schedule(); |
23955622 SL |
507 | } |
508 | __set_current_state(TASK_RUNNING); | |
509 | bio_put(bio); | |
510 | ||
1da177e4 | 511 | out: |
d8c47cc7 JW |
512 | if (workingset) |
513 | psi_memstall_leave(&pflags); | |
a3d5dc90 | 514 | delayacct_swapin_end(); |
1da177e4 LT |
515 | return ret; |
516 | } | |
5169b844 N |
517 | |
518 | void __swap_read_unplug(struct swap_iocb *sio) | |
519 | { | |
520 | struct iov_iter from; | |
521 | struct address_space *mapping = sio->iocb.ki_filp->f_mapping; | |
522 | int ret; | |
523 | ||
524 | iov_iter_bvec(&from, READ, sio->bvec, sio->pages, | |
525 | PAGE_SIZE * sio->pages); | |
526 | ret = mapping->a_ops->swap_rw(&sio->iocb, &from); | |
527 | if (ret != -EIOCBQUEUED) | |
528 | sio_read_complete(&sio->iocb, ret); | |
529 | } |