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Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * An async IO implementation for Linux | |
3 | * Written by Benjamin LaHaise <bcrl@kvack.org> | |
4 | * | |
5 | * Implements an efficient asynchronous io interface. | |
6 | * | |
7 | * Copyright 2000, 2001, 2002 Red Hat, Inc. All Rights Reserved. | |
bfe4037e | 8 | * Copyright 2018 Christoph Hellwig. |
1da177e4 LT |
9 | * |
10 | * See ../COPYING for licensing terms. | |
11 | */ | |
caf4167a KO |
12 | #define pr_fmt(fmt) "%s: " fmt, __func__ |
13 | ||
1da177e4 LT |
14 | #include <linux/kernel.h> |
15 | #include <linux/init.h> | |
16 | #include <linux/errno.h> | |
17 | #include <linux/time.h> | |
18 | #include <linux/aio_abi.h> | |
630d9c47 | 19 | #include <linux/export.h> |
1da177e4 | 20 | #include <linux/syscalls.h> |
b9d128f1 | 21 | #include <linux/backing-dev.h> |
9018ccc4 | 22 | #include <linux/refcount.h> |
027445c3 | 23 | #include <linux/uio.h> |
1da177e4 | 24 | |
174cd4b1 | 25 | #include <linux/sched/signal.h> |
1da177e4 LT |
26 | #include <linux/fs.h> |
27 | #include <linux/file.h> | |
28 | #include <linux/mm.h> | |
29 | #include <linux/mman.h> | |
3d2d827f | 30 | #include <linux/mmu_context.h> |
e1bdd5f2 | 31 | #include <linux/percpu.h> |
1da177e4 LT |
32 | #include <linux/slab.h> |
33 | #include <linux/timer.h> | |
34 | #include <linux/aio.h> | |
35 | #include <linux/highmem.h> | |
36 | #include <linux/workqueue.h> | |
37 | #include <linux/security.h> | |
9c3060be | 38 | #include <linux/eventfd.h> |
cfb1e33e | 39 | #include <linux/blkdev.h> |
9d85cba7 | 40 | #include <linux/compat.h> |
36bc08cc GZ |
41 | #include <linux/migrate.h> |
42 | #include <linux/ramfs.h> | |
723be6e3 | 43 | #include <linux/percpu-refcount.h> |
71ad7490 | 44 | #include <linux/mount.h> |
52db59df | 45 | #include <linux/pseudo_fs.h> |
1da177e4 LT |
46 | |
47 | #include <asm/kmap_types.h> | |
7c0f6ba6 | 48 | #include <linux/uaccess.h> |
a538e3ff | 49 | #include <linux/nospec.h> |
1da177e4 | 50 | |
68d70d03 AV |
51 | #include "internal.h" |
52 | ||
f3a2752a CH |
53 | #define KIOCB_KEY 0 |
54 | ||
4e179bca KO |
55 | #define AIO_RING_MAGIC 0xa10a10a1 |
56 | #define AIO_RING_COMPAT_FEATURES 1 | |
57 | #define AIO_RING_INCOMPAT_FEATURES 0 | |
58 | struct aio_ring { | |
59 | unsigned id; /* kernel internal index number */ | |
60 | unsigned nr; /* number of io_events */ | |
fa8a53c3 BL |
61 | unsigned head; /* Written to by userland or under ring_lock |
62 | * mutex by aio_read_events_ring(). */ | |
4e179bca KO |
63 | unsigned tail; |
64 | ||
65 | unsigned magic; | |
66 | unsigned compat_features; | |
67 | unsigned incompat_features; | |
68 | unsigned header_length; /* size of aio_ring */ | |
69 | ||
70 | ||
71 | struct io_event io_events[0]; | |
72 | }; /* 128 bytes + ring size */ | |
73 | ||
a79d40e9 JA |
74 | /* |
75 | * Plugging is meant to work with larger batches of IOs. If we don't | |
76 | * have more than the below, then don't bother setting up a plug. | |
77 | */ | |
78 | #define AIO_PLUG_THRESHOLD 2 | |
79 | ||
4e179bca | 80 | #define AIO_RING_PAGES 8 |
4e179bca | 81 | |
db446a08 | 82 | struct kioctx_table { |
d0264c01 TH |
83 | struct rcu_head rcu; |
84 | unsigned nr; | |
85 | struct kioctx __rcu *table[]; | |
db446a08 BL |
86 | }; |
87 | ||
e1bdd5f2 KO |
88 | struct kioctx_cpu { |
89 | unsigned reqs_available; | |
90 | }; | |
91 | ||
dc48e56d JA |
92 | struct ctx_rq_wait { |
93 | struct completion comp; | |
94 | atomic_t count; | |
95 | }; | |
96 | ||
4e179bca | 97 | struct kioctx { |
723be6e3 | 98 | struct percpu_ref users; |
36f55889 | 99 | atomic_t dead; |
4e179bca | 100 | |
e34ecee2 KO |
101 | struct percpu_ref reqs; |
102 | ||
4e179bca | 103 | unsigned long user_id; |
4e179bca | 104 | |
e1bdd5f2 KO |
105 | struct __percpu kioctx_cpu *cpu; |
106 | ||
107 | /* | |
108 | * For percpu reqs_available, number of slots we move to/from global | |
109 | * counter at a time: | |
110 | */ | |
111 | unsigned req_batch; | |
3e845ce0 KO |
112 | /* |
113 | * This is what userspace passed to io_setup(), it's not used for | |
114 | * anything but counting against the global max_reqs quota. | |
115 | * | |
58c85dc2 | 116 | * The real limit is nr_events - 1, which will be larger (see |
3e845ce0 KO |
117 | * aio_setup_ring()) |
118 | */ | |
4e179bca KO |
119 | unsigned max_reqs; |
120 | ||
58c85dc2 KO |
121 | /* Size of ringbuffer, in units of struct io_event */ |
122 | unsigned nr_events; | |
4e179bca | 123 | |
58c85dc2 KO |
124 | unsigned long mmap_base; |
125 | unsigned long mmap_size; | |
126 | ||
127 | struct page **ring_pages; | |
128 | long nr_pages; | |
129 | ||
f729863a | 130 | struct rcu_work free_rwork; /* see free_ioctx() */ |
4e23bcae | 131 | |
e02ba72a AP |
132 | /* |
133 | * signals when all in-flight requests are done | |
134 | */ | |
dc48e56d | 135 | struct ctx_rq_wait *rq_wait; |
e02ba72a | 136 | |
4e23bcae | 137 | struct { |
34e83fc6 KO |
138 | /* |
139 | * This counts the number of available slots in the ringbuffer, | |
140 | * so we avoid overflowing it: it's decremented (if positive) | |
141 | * when allocating a kiocb and incremented when the resulting | |
142 | * io_event is pulled off the ringbuffer. | |
e1bdd5f2 KO |
143 | * |
144 | * We batch accesses to it with a percpu version. | |
34e83fc6 KO |
145 | */ |
146 | atomic_t reqs_available; | |
4e23bcae KO |
147 | } ____cacheline_aligned_in_smp; |
148 | ||
149 | struct { | |
150 | spinlock_t ctx_lock; | |
151 | struct list_head active_reqs; /* used for cancellation */ | |
152 | } ____cacheline_aligned_in_smp; | |
153 | ||
58c85dc2 KO |
154 | struct { |
155 | struct mutex ring_lock; | |
4e23bcae KO |
156 | wait_queue_head_t wait; |
157 | } ____cacheline_aligned_in_smp; | |
58c85dc2 KO |
158 | |
159 | struct { | |
160 | unsigned tail; | |
d856f32a | 161 | unsigned completed_events; |
58c85dc2 | 162 | spinlock_t completion_lock; |
4e23bcae | 163 | } ____cacheline_aligned_in_smp; |
58c85dc2 KO |
164 | |
165 | struct page *internal_pages[AIO_RING_PAGES]; | |
36bc08cc | 166 | struct file *aio_ring_file; |
db446a08 BL |
167 | |
168 | unsigned id; | |
4e179bca KO |
169 | }; |
170 | ||
84c4e1f8 LT |
171 | /* |
172 | * First field must be the file pointer in all the | |
173 | * iocb unions! See also 'struct kiocb' in <linux/fs.h> | |
174 | */ | |
a3c0d439 | 175 | struct fsync_iocb { |
a3c0d439 | 176 | struct file *file; |
84c4e1f8 | 177 | struct work_struct work; |
a3c0d439 | 178 | bool datasync; |
87e329bc | 179 | struct cred *creds; |
a3c0d439 CH |
180 | }; |
181 | ||
bfe4037e CH |
182 | struct poll_iocb { |
183 | struct file *file; | |
184 | struct wait_queue_head *head; | |
185 | __poll_t events; | |
af5c72b1 | 186 | bool done; |
bfe4037e CH |
187 | bool cancelled; |
188 | struct wait_queue_entry wait; | |
189 | struct work_struct work; | |
190 | }; | |
191 | ||
84c4e1f8 LT |
192 | /* |
193 | * NOTE! Each of the iocb union members has the file pointer | |
194 | * as the first entry in their struct definition. So you can | |
195 | * access the file pointer through any of the sub-structs, | |
196 | * or directly as just 'ki_filp' in this struct. | |
197 | */ | |
04b2fa9f | 198 | struct aio_kiocb { |
54843f87 | 199 | union { |
84c4e1f8 | 200 | struct file *ki_filp; |
54843f87 | 201 | struct kiocb rw; |
a3c0d439 | 202 | struct fsync_iocb fsync; |
bfe4037e | 203 | struct poll_iocb poll; |
54843f87 | 204 | }; |
04b2fa9f CH |
205 | |
206 | struct kioctx *ki_ctx; | |
207 | kiocb_cancel_fn *ki_cancel; | |
208 | ||
a9339b78 | 209 | struct io_event ki_res; |
04b2fa9f CH |
210 | |
211 | struct list_head ki_list; /* the aio core uses this | |
212 | * for cancellation */ | |
9018ccc4 | 213 | refcount_t ki_refcnt; |
04b2fa9f CH |
214 | |
215 | /* | |
216 | * If the aio_resfd field of the userspace iocb is not zero, | |
217 | * this is the underlying eventfd context to deliver events to. | |
218 | */ | |
219 | struct eventfd_ctx *ki_eventfd; | |
220 | }; | |
221 | ||
1da177e4 | 222 | /*------ sysctl variables----*/ |
d55b5fda ZB |
223 | static DEFINE_SPINLOCK(aio_nr_lock); |
224 | unsigned long aio_nr; /* current system wide number of aio requests */ | |
225 | unsigned long aio_max_nr = 0x10000; /* system wide maximum number of aio requests */ | |
1da177e4 LT |
226 | /*----end sysctl variables---*/ |
227 | ||
e18b890b CL |
228 | static struct kmem_cache *kiocb_cachep; |
229 | static struct kmem_cache *kioctx_cachep; | |
1da177e4 | 230 | |
71ad7490 BL |
231 | static struct vfsmount *aio_mnt; |
232 | ||
233 | static const struct file_operations aio_ring_fops; | |
234 | static const struct address_space_operations aio_ctx_aops; | |
235 | ||
236 | static struct file *aio_private_file(struct kioctx *ctx, loff_t nr_pages) | |
237 | { | |
71ad7490 | 238 | struct file *file; |
71ad7490 | 239 | struct inode *inode = alloc_anon_inode(aio_mnt->mnt_sb); |
7f62656b DC |
240 | if (IS_ERR(inode)) |
241 | return ERR_CAST(inode); | |
71ad7490 BL |
242 | |
243 | inode->i_mapping->a_ops = &aio_ctx_aops; | |
244 | inode->i_mapping->private_data = ctx; | |
245 | inode->i_size = PAGE_SIZE * nr_pages; | |
246 | ||
d93aa9d8 AV |
247 | file = alloc_file_pseudo(inode, aio_mnt, "[aio]", |
248 | O_RDWR, &aio_ring_fops); | |
c9c554f2 | 249 | if (IS_ERR(file)) |
71ad7490 | 250 | iput(inode); |
71ad7490 BL |
251 | return file; |
252 | } | |
253 | ||
52db59df | 254 | static int aio_init_fs_context(struct fs_context *fc) |
71ad7490 | 255 | { |
52db59df DH |
256 | if (!init_pseudo(fc, AIO_RING_MAGIC)) |
257 | return -ENOMEM; | |
258 | fc->s_iflags |= SB_I_NOEXEC; | |
259 | return 0; | |
71ad7490 BL |
260 | } |
261 | ||
1da177e4 LT |
262 | /* aio_setup |
263 | * Creates the slab caches used by the aio routines, panic on | |
264 | * failure as this is done early during the boot sequence. | |
265 | */ | |
266 | static int __init aio_setup(void) | |
267 | { | |
71ad7490 BL |
268 | static struct file_system_type aio_fs = { |
269 | .name = "aio", | |
52db59df | 270 | .init_fs_context = aio_init_fs_context, |
71ad7490 BL |
271 | .kill_sb = kill_anon_super, |
272 | }; | |
273 | aio_mnt = kern_mount(&aio_fs); | |
274 | if (IS_ERR(aio_mnt)) | |
275 | panic("Failed to create aio fs mount."); | |
276 | ||
04b2fa9f | 277 | kiocb_cachep = KMEM_CACHE(aio_kiocb, SLAB_HWCACHE_ALIGN|SLAB_PANIC); |
0a31bd5f | 278 | kioctx_cachep = KMEM_CACHE(kioctx,SLAB_HWCACHE_ALIGN|SLAB_PANIC); |
1da177e4 LT |
279 | return 0; |
280 | } | |
385773e0 | 281 | __initcall(aio_setup); |
1da177e4 | 282 | |
5e9ae2e5 BL |
283 | static void put_aio_ring_file(struct kioctx *ctx) |
284 | { | |
285 | struct file *aio_ring_file = ctx->aio_ring_file; | |
de04e769 RV |
286 | struct address_space *i_mapping; |
287 | ||
5e9ae2e5 | 288 | if (aio_ring_file) { |
45063097 | 289 | truncate_setsize(file_inode(aio_ring_file), 0); |
5e9ae2e5 BL |
290 | |
291 | /* Prevent further access to the kioctx from migratepages */ | |
45063097 | 292 | i_mapping = aio_ring_file->f_mapping; |
de04e769 RV |
293 | spin_lock(&i_mapping->private_lock); |
294 | i_mapping->private_data = NULL; | |
5e9ae2e5 | 295 | ctx->aio_ring_file = NULL; |
de04e769 | 296 | spin_unlock(&i_mapping->private_lock); |
5e9ae2e5 BL |
297 | |
298 | fput(aio_ring_file); | |
299 | } | |
300 | } | |
301 | ||
1da177e4 LT |
302 | static void aio_free_ring(struct kioctx *ctx) |
303 | { | |
36bc08cc | 304 | int i; |
1da177e4 | 305 | |
fa8a53c3 BL |
306 | /* Disconnect the kiotx from the ring file. This prevents future |
307 | * accesses to the kioctx from page migration. | |
308 | */ | |
309 | put_aio_ring_file(ctx); | |
310 | ||
36bc08cc | 311 | for (i = 0; i < ctx->nr_pages; i++) { |
8e321fef | 312 | struct page *page; |
36bc08cc GZ |
313 | pr_debug("pid(%d) [%d] page->count=%d\n", current->pid, i, |
314 | page_count(ctx->ring_pages[i])); | |
8e321fef BL |
315 | page = ctx->ring_pages[i]; |
316 | if (!page) | |
317 | continue; | |
318 | ctx->ring_pages[i] = NULL; | |
319 | put_page(page); | |
36bc08cc | 320 | } |
1da177e4 | 321 | |
ddb8c45b | 322 | if (ctx->ring_pages && ctx->ring_pages != ctx->internal_pages) { |
58c85dc2 | 323 | kfree(ctx->ring_pages); |
ddb8c45b SL |
324 | ctx->ring_pages = NULL; |
325 | } | |
36bc08cc GZ |
326 | } |
327 | ||
5477e70a | 328 | static int aio_ring_mremap(struct vm_area_struct *vma) |
e4a0d3e7 | 329 | { |
5477e70a | 330 | struct file *file = vma->vm_file; |
e4a0d3e7 PE |
331 | struct mm_struct *mm = vma->vm_mm; |
332 | struct kioctx_table *table; | |
b2edffdd | 333 | int i, res = -EINVAL; |
e4a0d3e7 PE |
334 | |
335 | spin_lock(&mm->ioctx_lock); | |
336 | rcu_read_lock(); | |
337 | table = rcu_dereference(mm->ioctx_table); | |
338 | for (i = 0; i < table->nr; i++) { | |
339 | struct kioctx *ctx; | |
340 | ||
d0264c01 | 341 | ctx = rcu_dereference(table->table[i]); |
e4a0d3e7 | 342 | if (ctx && ctx->aio_ring_file == file) { |
b2edffdd AV |
343 | if (!atomic_read(&ctx->dead)) { |
344 | ctx->user_id = ctx->mmap_base = vma->vm_start; | |
345 | res = 0; | |
346 | } | |
e4a0d3e7 PE |
347 | break; |
348 | } | |
349 | } | |
350 | ||
351 | rcu_read_unlock(); | |
352 | spin_unlock(&mm->ioctx_lock); | |
b2edffdd | 353 | return res; |
e4a0d3e7 PE |
354 | } |
355 | ||
5477e70a ON |
356 | static const struct vm_operations_struct aio_ring_vm_ops = { |
357 | .mremap = aio_ring_mremap, | |
358 | #if IS_ENABLED(CONFIG_MMU) | |
359 | .fault = filemap_fault, | |
360 | .map_pages = filemap_map_pages, | |
361 | .page_mkwrite = filemap_page_mkwrite, | |
362 | #endif | |
363 | }; | |
364 | ||
365 | static int aio_ring_mmap(struct file *file, struct vm_area_struct *vma) | |
366 | { | |
367 | vma->vm_flags |= VM_DONTEXPAND; | |
368 | vma->vm_ops = &aio_ring_vm_ops; | |
369 | return 0; | |
370 | } | |
371 | ||
36bc08cc GZ |
372 | static const struct file_operations aio_ring_fops = { |
373 | .mmap = aio_ring_mmap, | |
374 | }; | |
375 | ||
0c45355f | 376 | #if IS_ENABLED(CONFIG_MIGRATION) |
36bc08cc GZ |
377 | static int aio_migratepage(struct address_space *mapping, struct page *new, |
378 | struct page *old, enum migrate_mode mode) | |
379 | { | |
5e9ae2e5 | 380 | struct kioctx *ctx; |
36bc08cc | 381 | unsigned long flags; |
fa8a53c3 | 382 | pgoff_t idx; |
36bc08cc GZ |
383 | int rc; |
384 | ||
2916ecc0 JG |
385 | /* |
386 | * We cannot support the _NO_COPY case here, because copy needs to | |
387 | * happen under the ctx->completion_lock. That does not work with the | |
388 | * migration workflow of MIGRATE_SYNC_NO_COPY. | |
389 | */ | |
390 | if (mode == MIGRATE_SYNC_NO_COPY) | |
391 | return -EINVAL; | |
392 | ||
8e321fef BL |
393 | rc = 0; |
394 | ||
fa8a53c3 | 395 | /* mapping->private_lock here protects against the kioctx teardown. */ |
8e321fef BL |
396 | spin_lock(&mapping->private_lock); |
397 | ctx = mapping->private_data; | |
fa8a53c3 BL |
398 | if (!ctx) { |
399 | rc = -EINVAL; | |
400 | goto out; | |
401 | } | |
402 | ||
403 | /* The ring_lock mutex. The prevents aio_read_events() from writing | |
404 | * to the ring's head, and prevents page migration from mucking in | |
405 | * a partially initialized kiotx. | |
406 | */ | |
407 | if (!mutex_trylock(&ctx->ring_lock)) { | |
408 | rc = -EAGAIN; | |
409 | goto out; | |
410 | } | |
411 | ||
412 | idx = old->index; | |
413 | if (idx < (pgoff_t)ctx->nr_pages) { | |
414 | /* Make sure the old page hasn't already been changed */ | |
415 | if (ctx->ring_pages[idx] != old) | |
416 | rc = -EAGAIN; | |
8e321fef BL |
417 | } else |
418 | rc = -EINVAL; | |
8e321fef BL |
419 | |
420 | if (rc != 0) | |
fa8a53c3 | 421 | goto out_unlock; |
8e321fef | 422 | |
36bc08cc GZ |
423 | /* Writeback must be complete */ |
424 | BUG_ON(PageWriteback(old)); | |
8e321fef | 425 | get_page(new); |
36bc08cc | 426 | |
37109694 | 427 | rc = migrate_page_move_mapping(mapping, new, old, 1); |
36bc08cc | 428 | if (rc != MIGRATEPAGE_SUCCESS) { |
8e321fef | 429 | put_page(new); |
fa8a53c3 | 430 | goto out_unlock; |
36bc08cc GZ |
431 | } |
432 | ||
fa8a53c3 BL |
433 | /* Take completion_lock to prevent other writes to the ring buffer |
434 | * while the old page is copied to the new. This prevents new | |
435 | * events from being lost. | |
5e9ae2e5 | 436 | */ |
fa8a53c3 BL |
437 | spin_lock_irqsave(&ctx->completion_lock, flags); |
438 | migrate_page_copy(new, old); | |
439 | BUG_ON(ctx->ring_pages[idx] != old); | |
440 | ctx->ring_pages[idx] = new; | |
441 | spin_unlock_irqrestore(&ctx->completion_lock, flags); | |
36bc08cc | 442 | |
fa8a53c3 BL |
443 | /* The old page is no longer accessible. */ |
444 | put_page(old); | |
8e321fef | 445 | |
fa8a53c3 BL |
446 | out_unlock: |
447 | mutex_unlock(&ctx->ring_lock); | |
448 | out: | |
449 | spin_unlock(&mapping->private_lock); | |
36bc08cc | 450 | return rc; |
1da177e4 | 451 | } |
0c45355f | 452 | #endif |
1da177e4 | 453 | |
36bc08cc | 454 | static const struct address_space_operations aio_ctx_aops = { |
835f252c | 455 | .set_page_dirty = __set_page_dirty_no_writeback, |
0c45355f | 456 | #if IS_ENABLED(CONFIG_MIGRATION) |
36bc08cc | 457 | .migratepage = aio_migratepage, |
0c45355f | 458 | #endif |
36bc08cc GZ |
459 | }; |
460 | ||
2a8a9867 | 461 | static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events) |
1da177e4 LT |
462 | { |
463 | struct aio_ring *ring; | |
41003a7b | 464 | struct mm_struct *mm = current->mm; |
3dc9acb6 | 465 | unsigned long size, unused; |
1da177e4 | 466 | int nr_pages; |
36bc08cc GZ |
467 | int i; |
468 | struct file *file; | |
1da177e4 LT |
469 | |
470 | /* Compensate for the ring buffer's head/tail overlap entry */ | |
471 | nr_events += 2; /* 1 is required, 2 for good luck */ | |
472 | ||
473 | size = sizeof(struct aio_ring); | |
474 | size += sizeof(struct io_event) * nr_events; | |
1da177e4 | 475 | |
36bc08cc | 476 | nr_pages = PFN_UP(size); |
1da177e4 LT |
477 | if (nr_pages < 0) |
478 | return -EINVAL; | |
479 | ||
71ad7490 | 480 | file = aio_private_file(ctx, nr_pages); |
36bc08cc GZ |
481 | if (IS_ERR(file)) { |
482 | ctx->aio_ring_file = NULL; | |
fa8a53c3 | 483 | return -ENOMEM; |
36bc08cc GZ |
484 | } |
485 | ||
3dc9acb6 LT |
486 | ctx->aio_ring_file = file; |
487 | nr_events = (PAGE_SIZE * nr_pages - sizeof(struct aio_ring)) | |
488 | / sizeof(struct io_event); | |
489 | ||
490 | ctx->ring_pages = ctx->internal_pages; | |
491 | if (nr_pages > AIO_RING_PAGES) { | |
492 | ctx->ring_pages = kcalloc(nr_pages, sizeof(struct page *), | |
493 | GFP_KERNEL); | |
494 | if (!ctx->ring_pages) { | |
495 | put_aio_ring_file(ctx); | |
496 | return -ENOMEM; | |
497 | } | |
498 | } | |
499 | ||
36bc08cc GZ |
500 | for (i = 0; i < nr_pages; i++) { |
501 | struct page *page; | |
45063097 | 502 | page = find_or_create_page(file->f_mapping, |
36bc08cc GZ |
503 | i, GFP_HIGHUSER | __GFP_ZERO); |
504 | if (!page) | |
505 | break; | |
506 | pr_debug("pid(%d) page[%d]->count=%d\n", | |
507 | current->pid, i, page_count(page)); | |
508 | SetPageUptodate(page); | |
36bc08cc | 509 | unlock_page(page); |
3dc9acb6 LT |
510 | |
511 | ctx->ring_pages[i] = page; | |
36bc08cc | 512 | } |
3dc9acb6 | 513 | ctx->nr_pages = i; |
1da177e4 | 514 | |
3dc9acb6 LT |
515 | if (unlikely(i != nr_pages)) { |
516 | aio_free_ring(ctx); | |
fa8a53c3 | 517 | return -ENOMEM; |
1da177e4 LT |
518 | } |
519 | ||
58c85dc2 KO |
520 | ctx->mmap_size = nr_pages * PAGE_SIZE; |
521 | pr_debug("attempting mmap of %lu bytes\n", ctx->mmap_size); | |
36bc08cc | 522 | |
013373e8 MH |
523 | if (down_write_killable(&mm->mmap_sem)) { |
524 | ctx->mmap_size = 0; | |
525 | aio_free_ring(ctx); | |
526 | return -EINTR; | |
527 | } | |
528 | ||
36bc08cc GZ |
529 | ctx->mmap_base = do_mmap_pgoff(ctx->aio_ring_file, 0, ctx->mmap_size, |
530 | PROT_READ | PROT_WRITE, | |
897ab3e0 | 531 | MAP_SHARED, 0, &unused, NULL); |
3dc9acb6 | 532 | up_write(&mm->mmap_sem); |
58c85dc2 | 533 | if (IS_ERR((void *)ctx->mmap_base)) { |
58c85dc2 | 534 | ctx->mmap_size = 0; |
1da177e4 | 535 | aio_free_ring(ctx); |
fa8a53c3 | 536 | return -ENOMEM; |
1da177e4 LT |
537 | } |
538 | ||
58c85dc2 | 539 | pr_debug("mmap address: 0x%08lx\n", ctx->mmap_base); |
d6c355c7 | 540 | |
58c85dc2 KO |
541 | ctx->user_id = ctx->mmap_base; |
542 | ctx->nr_events = nr_events; /* trusted copy */ | |
1da177e4 | 543 | |
58c85dc2 | 544 | ring = kmap_atomic(ctx->ring_pages[0]); |
1da177e4 | 545 | ring->nr = nr_events; /* user copy */ |
db446a08 | 546 | ring->id = ~0U; |
1da177e4 LT |
547 | ring->head = ring->tail = 0; |
548 | ring->magic = AIO_RING_MAGIC; | |
549 | ring->compat_features = AIO_RING_COMPAT_FEATURES; | |
550 | ring->incompat_features = AIO_RING_INCOMPAT_FEATURES; | |
551 | ring->header_length = sizeof(struct aio_ring); | |
e8e3c3d6 | 552 | kunmap_atomic(ring); |
58c85dc2 | 553 | flush_dcache_page(ctx->ring_pages[0]); |
1da177e4 LT |
554 | |
555 | return 0; | |
556 | } | |
557 | ||
1da177e4 LT |
558 | #define AIO_EVENTS_PER_PAGE (PAGE_SIZE / sizeof(struct io_event)) |
559 | #define AIO_EVENTS_FIRST_PAGE ((PAGE_SIZE - sizeof(struct aio_ring)) / sizeof(struct io_event)) | |
560 | #define AIO_EVENTS_OFFSET (AIO_EVENTS_PER_PAGE - AIO_EVENTS_FIRST_PAGE) | |
561 | ||
04b2fa9f | 562 | void kiocb_set_cancel_fn(struct kiocb *iocb, kiocb_cancel_fn *cancel) |
0460fef2 | 563 | { |
54843f87 | 564 | struct aio_kiocb *req = container_of(iocb, struct aio_kiocb, rw); |
0460fef2 KO |
565 | struct kioctx *ctx = req->ki_ctx; |
566 | unsigned long flags; | |
567 | ||
75321b50 CH |
568 | if (WARN_ON_ONCE(!list_empty(&req->ki_list))) |
569 | return; | |
0460fef2 | 570 | |
75321b50 CH |
571 | spin_lock_irqsave(&ctx->ctx_lock, flags); |
572 | list_add_tail(&req->ki_list, &ctx->active_reqs); | |
0460fef2 | 573 | req->ki_cancel = cancel; |
0460fef2 KO |
574 | spin_unlock_irqrestore(&ctx->ctx_lock, flags); |
575 | } | |
576 | EXPORT_SYMBOL(kiocb_set_cancel_fn); | |
577 | ||
a6d7cff4 TH |
578 | /* |
579 | * free_ioctx() should be RCU delayed to synchronize against the RCU | |
580 | * protected lookup_ioctx() and also needs process context to call | |
f729863a | 581 | * aio_free_ring(). Use rcu_work. |
a6d7cff4 | 582 | */ |
e34ecee2 | 583 | static void free_ioctx(struct work_struct *work) |
36f55889 | 584 | { |
f729863a TH |
585 | struct kioctx *ctx = container_of(to_rcu_work(work), struct kioctx, |
586 | free_rwork); | |
e34ecee2 | 587 | pr_debug("freeing %p\n", ctx); |
e1bdd5f2 | 588 | |
e34ecee2 | 589 | aio_free_ring(ctx); |
e1bdd5f2 | 590 | free_percpu(ctx->cpu); |
9a1049da TH |
591 | percpu_ref_exit(&ctx->reqs); |
592 | percpu_ref_exit(&ctx->users); | |
36f55889 KO |
593 | kmem_cache_free(kioctx_cachep, ctx); |
594 | } | |
595 | ||
e34ecee2 KO |
596 | static void free_ioctx_reqs(struct percpu_ref *ref) |
597 | { | |
598 | struct kioctx *ctx = container_of(ref, struct kioctx, reqs); | |
599 | ||
e02ba72a | 600 | /* At this point we know that there are no any in-flight requests */ |
dc48e56d JA |
601 | if (ctx->rq_wait && atomic_dec_and_test(&ctx->rq_wait->count)) |
602 | complete(&ctx->rq_wait->comp); | |
e02ba72a | 603 | |
a6d7cff4 | 604 | /* Synchronize against RCU protected table->table[] dereferences */ |
f729863a TH |
605 | INIT_RCU_WORK(&ctx->free_rwork, free_ioctx); |
606 | queue_rcu_work(system_wq, &ctx->free_rwork); | |
e34ecee2 KO |
607 | } |
608 | ||
36f55889 KO |
609 | /* |
610 | * When this function runs, the kioctx has been removed from the "hash table" | |
611 | * and ctx->users has dropped to 0, so we know no more kiocbs can be submitted - | |
612 | * now it's safe to cancel any that need to be. | |
613 | */ | |
e34ecee2 | 614 | static void free_ioctx_users(struct percpu_ref *ref) |
36f55889 | 615 | { |
e34ecee2 | 616 | struct kioctx *ctx = container_of(ref, struct kioctx, users); |
04b2fa9f | 617 | struct aio_kiocb *req; |
36f55889 KO |
618 | |
619 | spin_lock_irq(&ctx->ctx_lock); | |
620 | ||
621 | while (!list_empty(&ctx->active_reqs)) { | |
622 | req = list_first_entry(&ctx->active_reqs, | |
04b2fa9f | 623 | struct aio_kiocb, ki_list); |
888933f8 | 624 | req->ki_cancel(&req->rw); |
4faa9996 | 625 | list_del_init(&req->ki_list); |
36f55889 KO |
626 | } |
627 | ||
628 | spin_unlock_irq(&ctx->ctx_lock); | |
629 | ||
e34ecee2 KO |
630 | percpu_ref_kill(&ctx->reqs); |
631 | percpu_ref_put(&ctx->reqs); | |
36f55889 KO |
632 | } |
633 | ||
db446a08 BL |
634 | static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm) |
635 | { | |
636 | unsigned i, new_nr; | |
637 | struct kioctx_table *table, *old; | |
638 | struct aio_ring *ring; | |
639 | ||
640 | spin_lock(&mm->ioctx_lock); | |
855ef0de | 641 | table = rcu_dereference_raw(mm->ioctx_table); |
db446a08 BL |
642 | |
643 | while (1) { | |
644 | if (table) | |
645 | for (i = 0; i < table->nr; i++) | |
d0264c01 | 646 | if (!rcu_access_pointer(table->table[i])) { |
db446a08 | 647 | ctx->id = i; |
d0264c01 | 648 | rcu_assign_pointer(table->table[i], ctx); |
db446a08 BL |
649 | spin_unlock(&mm->ioctx_lock); |
650 | ||
fa8a53c3 BL |
651 | /* While kioctx setup is in progress, |
652 | * we are protected from page migration | |
653 | * changes ring_pages by ->ring_lock. | |
654 | */ | |
db446a08 BL |
655 | ring = kmap_atomic(ctx->ring_pages[0]); |
656 | ring->id = ctx->id; | |
657 | kunmap_atomic(ring); | |
658 | return 0; | |
659 | } | |
660 | ||
661 | new_nr = (table ? table->nr : 1) * 4; | |
db446a08 BL |
662 | spin_unlock(&mm->ioctx_lock); |
663 | ||
664 | table = kzalloc(sizeof(*table) + sizeof(struct kioctx *) * | |
665 | new_nr, GFP_KERNEL); | |
666 | if (!table) | |
667 | return -ENOMEM; | |
668 | ||
669 | table->nr = new_nr; | |
670 | ||
671 | spin_lock(&mm->ioctx_lock); | |
855ef0de | 672 | old = rcu_dereference_raw(mm->ioctx_table); |
db446a08 BL |
673 | |
674 | if (!old) { | |
675 | rcu_assign_pointer(mm->ioctx_table, table); | |
676 | } else if (table->nr > old->nr) { | |
677 | memcpy(table->table, old->table, | |
678 | old->nr * sizeof(struct kioctx *)); | |
679 | ||
680 | rcu_assign_pointer(mm->ioctx_table, table); | |
681 | kfree_rcu(old, rcu); | |
682 | } else { | |
683 | kfree(table); | |
684 | table = old; | |
685 | } | |
686 | } | |
687 | } | |
688 | ||
e34ecee2 KO |
689 | static void aio_nr_sub(unsigned nr) |
690 | { | |
691 | spin_lock(&aio_nr_lock); | |
692 | if (WARN_ON(aio_nr - nr > aio_nr)) | |
693 | aio_nr = 0; | |
694 | else | |
695 | aio_nr -= nr; | |
696 | spin_unlock(&aio_nr_lock); | |
697 | } | |
698 | ||
1da177e4 LT |
699 | /* ioctx_alloc |
700 | * Allocates and initializes an ioctx. Returns an ERR_PTR if it failed. | |
701 | */ | |
702 | static struct kioctx *ioctx_alloc(unsigned nr_events) | |
703 | { | |
41003a7b | 704 | struct mm_struct *mm = current->mm; |
1da177e4 | 705 | struct kioctx *ctx; |
e23754f8 | 706 | int err = -ENOMEM; |
1da177e4 | 707 | |
2a8a9867 MFO |
708 | /* |
709 | * Store the original nr_events -- what userspace passed to io_setup(), | |
710 | * for counting against the global limit -- before it changes. | |
711 | */ | |
712 | unsigned int max_reqs = nr_events; | |
713 | ||
e1bdd5f2 KO |
714 | /* |
715 | * We keep track of the number of available ringbuffer slots, to prevent | |
716 | * overflow (reqs_available), and we also use percpu counters for this. | |
717 | * | |
718 | * So since up to half the slots might be on other cpu's percpu counters | |
719 | * and unavailable, double nr_events so userspace sees what they | |
720 | * expected: additionally, we move req_batch slots to/from percpu | |
721 | * counters at a time, so make sure that isn't 0: | |
722 | */ | |
723 | nr_events = max(nr_events, num_possible_cpus() * 4); | |
724 | nr_events *= 2; | |
725 | ||
1da177e4 | 726 | /* Prevent overflows */ |
08397acd | 727 | if (nr_events > (0x10000000U / sizeof(struct io_event))) { |
1da177e4 LT |
728 | pr_debug("ENOMEM: nr_events too high\n"); |
729 | return ERR_PTR(-EINVAL); | |
730 | } | |
731 | ||
2a8a9867 | 732 | if (!nr_events || (unsigned long)max_reqs > aio_max_nr) |
1da177e4 LT |
733 | return ERR_PTR(-EAGAIN); |
734 | ||
c3762229 | 735 | ctx = kmem_cache_zalloc(kioctx_cachep, GFP_KERNEL); |
1da177e4 LT |
736 | if (!ctx) |
737 | return ERR_PTR(-ENOMEM); | |
738 | ||
2a8a9867 | 739 | ctx->max_reqs = max_reqs; |
1da177e4 | 740 | |
1da177e4 | 741 | spin_lock_init(&ctx->ctx_lock); |
0460fef2 | 742 | spin_lock_init(&ctx->completion_lock); |
58c85dc2 | 743 | mutex_init(&ctx->ring_lock); |
fa8a53c3 BL |
744 | /* Protect against page migration throughout kiotx setup by keeping |
745 | * the ring_lock mutex held until setup is complete. */ | |
746 | mutex_lock(&ctx->ring_lock); | |
1da177e4 LT |
747 | init_waitqueue_head(&ctx->wait); |
748 | ||
749 | INIT_LIST_HEAD(&ctx->active_reqs); | |
1da177e4 | 750 | |
2aad2a86 | 751 | if (percpu_ref_init(&ctx->users, free_ioctx_users, 0, GFP_KERNEL)) |
fa8a53c3 BL |
752 | goto err; |
753 | ||
2aad2a86 | 754 | if (percpu_ref_init(&ctx->reqs, free_ioctx_reqs, 0, GFP_KERNEL)) |
fa8a53c3 BL |
755 | goto err; |
756 | ||
e1bdd5f2 KO |
757 | ctx->cpu = alloc_percpu(struct kioctx_cpu); |
758 | if (!ctx->cpu) | |
e34ecee2 | 759 | goto err; |
1da177e4 | 760 | |
2a8a9867 | 761 | err = aio_setup_ring(ctx, nr_events); |
fa8a53c3 | 762 | if (err < 0) |
e34ecee2 | 763 | goto err; |
e1bdd5f2 | 764 | |
34e83fc6 | 765 | atomic_set(&ctx->reqs_available, ctx->nr_events - 1); |
e1bdd5f2 | 766 | ctx->req_batch = (ctx->nr_events - 1) / (num_possible_cpus() * 4); |
6878ea72 BL |
767 | if (ctx->req_batch < 1) |
768 | ctx->req_batch = 1; | |
34e83fc6 | 769 | |
1da177e4 | 770 | /* limit the number of system wide aios */ |
9fa1cb39 | 771 | spin_lock(&aio_nr_lock); |
2a8a9867 MFO |
772 | if (aio_nr + ctx->max_reqs > aio_max_nr || |
773 | aio_nr + ctx->max_reqs < aio_nr) { | |
9fa1cb39 | 774 | spin_unlock(&aio_nr_lock); |
e34ecee2 | 775 | err = -EAGAIN; |
d1b94327 | 776 | goto err_ctx; |
2dd542b7 AV |
777 | } |
778 | aio_nr += ctx->max_reqs; | |
9fa1cb39 | 779 | spin_unlock(&aio_nr_lock); |
1da177e4 | 780 | |
1881686f BL |
781 | percpu_ref_get(&ctx->users); /* io_setup() will drop this ref */ |
782 | percpu_ref_get(&ctx->reqs); /* free_ioctx_users() will drop this */ | |
723be6e3 | 783 | |
da90382c BL |
784 | err = ioctx_add_table(ctx, mm); |
785 | if (err) | |
e34ecee2 | 786 | goto err_cleanup; |
da90382c | 787 | |
fa8a53c3 BL |
788 | /* Release the ring_lock mutex now that all setup is complete. */ |
789 | mutex_unlock(&ctx->ring_lock); | |
790 | ||
caf4167a | 791 | pr_debug("allocated ioctx %p[%ld]: mm=%p mask=0x%x\n", |
58c85dc2 | 792 | ctx, ctx->user_id, mm, ctx->nr_events); |
1da177e4 LT |
793 | return ctx; |
794 | ||
e34ecee2 KO |
795 | err_cleanup: |
796 | aio_nr_sub(ctx->max_reqs); | |
d1b94327 | 797 | err_ctx: |
deeb8525 AV |
798 | atomic_set(&ctx->dead, 1); |
799 | if (ctx->mmap_size) | |
800 | vm_munmap(ctx->mmap_base, ctx->mmap_size); | |
d1b94327 | 801 | aio_free_ring(ctx); |
e34ecee2 | 802 | err: |
fa8a53c3 | 803 | mutex_unlock(&ctx->ring_lock); |
e1bdd5f2 | 804 | free_percpu(ctx->cpu); |
9a1049da TH |
805 | percpu_ref_exit(&ctx->reqs); |
806 | percpu_ref_exit(&ctx->users); | |
1da177e4 | 807 | kmem_cache_free(kioctx_cachep, ctx); |
caf4167a | 808 | pr_debug("error allocating ioctx %d\n", err); |
e23754f8 | 809 | return ERR_PTR(err); |
1da177e4 LT |
810 | } |
811 | ||
36f55889 KO |
812 | /* kill_ioctx |
813 | * Cancels all outstanding aio requests on an aio context. Used | |
814 | * when the processes owning a context have all exited to encourage | |
815 | * the rapid destruction of the kioctx. | |
816 | */ | |
fb2d4483 | 817 | static int kill_ioctx(struct mm_struct *mm, struct kioctx *ctx, |
dc48e56d | 818 | struct ctx_rq_wait *wait) |
36f55889 | 819 | { |
fa88b6f8 | 820 | struct kioctx_table *table; |
db446a08 | 821 | |
b2edffdd AV |
822 | spin_lock(&mm->ioctx_lock); |
823 | if (atomic_xchg(&ctx->dead, 1)) { | |
824 | spin_unlock(&mm->ioctx_lock); | |
fa88b6f8 | 825 | return -EINVAL; |
b2edffdd | 826 | } |
db446a08 | 827 | |
855ef0de | 828 | table = rcu_dereference_raw(mm->ioctx_table); |
d0264c01 TH |
829 | WARN_ON(ctx != rcu_access_pointer(table->table[ctx->id])); |
830 | RCU_INIT_POINTER(table->table[ctx->id], NULL); | |
fa88b6f8 | 831 | spin_unlock(&mm->ioctx_lock); |
4fcc712f | 832 | |
a6d7cff4 | 833 | /* free_ioctx_reqs() will do the necessary RCU synchronization */ |
fa88b6f8 | 834 | wake_up_all(&ctx->wait); |
4fcc712f | 835 | |
fa88b6f8 BL |
836 | /* |
837 | * It'd be more correct to do this in free_ioctx(), after all | |
838 | * the outstanding kiocbs have finished - but by then io_destroy | |
839 | * has already returned, so io_setup() could potentially return | |
840 | * -EAGAIN with no ioctxs actually in use (as far as userspace | |
841 | * could tell). | |
842 | */ | |
843 | aio_nr_sub(ctx->max_reqs); | |
4fcc712f | 844 | |
fa88b6f8 BL |
845 | if (ctx->mmap_size) |
846 | vm_munmap(ctx->mmap_base, ctx->mmap_size); | |
fb2d4483 | 847 | |
dc48e56d | 848 | ctx->rq_wait = wait; |
fa88b6f8 BL |
849 | percpu_ref_kill(&ctx->users); |
850 | return 0; | |
1da177e4 LT |
851 | } |
852 | ||
36f55889 KO |
853 | /* |
854 | * exit_aio: called when the last user of mm goes away. At this point, there is | |
855 | * no way for any new requests to be submited or any of the io_* syscalls to be | |
856 | * called on the context. | |
857 | * | |
858 | * There may be outstanding kiocbs, but free_ioctx() will explicitly wait on | |
859 | * them. | |
1da177e4 | 860 | */ |
fc9b52cd | 861 | void exit_aio(struct mm_struct *mm) |
1da177e4 | 862 | { |
4b70ac5f | 863 | struct kioctx_table *table = rcu_dereference_raw(mm->ioctx_table); |
dc48e56d JA |
864 | struct ctx_rq_wait wait; |
865 | int i, skipped; | |
db446a08 | 866 | |
4b70ac5f ON |
867 | if (!table) |
868 | return; | |
db446a08 | 869 | |
dc48e56d JA |
870 | atomic_set(&wait.count, table->nr); |
871 | init_completion(&wait.comp); | |
872 | ||
873 | skipped = 0; | |
4b70ac5f | 874 | for (i = 0; i < table->nr; ++i) { |
d0264c01 TH |
875 | struct kioctx *ctx = |
876 | rcu_dereference_protected(table->table[i], true); | |
abf137dd | 877 | |
dc48e56d JA |
878 | if (!ctx) { |
879 | skipped++; | |
4b70ac5f | 880 | continue; |
dc48e56d JA |
881 | } |
882 | ||
936af157 | 883 | /* |
4b70ac5f ON |
884 | * We don't need to bother with munmap() here - exit_mmap(mm) |
885 | * is coming and it'll unmap everything. And we simply can't, | |
886 | * this is not necessarily our ->mm. | |
887 | * Since kill_ioctx() uses non-zero ->mmap_size as indicator | |
888 | * that it needs to unmap the area, just set it to 0. | |
936af157 | 889 | */ |
58c85dc2 | 890 | ctx->mmap_size = 0; |
dc48e56d JA |
891 | kill_ioctx(mm, ctx, &wait); |
892 | } | |
36f55889 | 893 | |
dc48e56d | 894 | if (!atomic_sub_and_test(skipped, &wait.count)) { |
6098b45b | 895 | /* Wait until all IO for the context are done. */ |
dc48e56d | 896 | wait_for_completion(&wait.comp); |
1da177e4 | 897 | } |
4b70ac5f ON |
898 | |
899 | RCU_INIT_POINTER(mm->ioctx_table, NULL); | |
900 | kfree(table); | |
1da177e4 LT |
901 | } |
902 | ||
e1bdd5f2 KO |
903 | static void put_reqs_available(struct kioctx *ctx, unsigned nr) |
904 | { | |
905 | struct kioctx_cpu *kcpu; | |
263782c1 | 906 | unsigned long flags; |
e1bdd5f2 | 907 | |
263782c1 | 908 | local_irq_save(flags); |
be6fb451 | 909 | kcpu = this_cpu_ptr(ctx->cpu); |
e1bdd5f2 | 910 | kcpu->reqs_available += nr; |
263782c1 | 911 | |
e1bdd5f2 KO |
912 | while (kcpu->reqs_available >= ctx->req_batch * 2) { |
913 | kcpu->reqs_available -= ctx->req_batch; | |
914 | atomic_add(ctx->req_batch, &ctx->reqs_available); | |
915 | } | |
916 | ||
263782c1 | 917 | local_irq_restore(flags); |
e1bdd5f2 KO |
918 | } |
919 | ||
432c7997 | 920 | static bool __get_reqs_available(struct kioctx *ctx) |
e1bdd5f2 KO |
921 | { |
922 | struct kioctx_cpu *kcpu; | |
923 | bool ret = false; | |
263782c1 | 924 | unsigned long flags; |
e1bdd5f2 | 925 | |
263782c1 | 926 | local_irq_save(flags); |
be6fb451 | 927 | kcpu = this_cpu_ptr(ctx->cpu); |
e1bdd5f2 KO |
928 | if (!kcpu->reqs_available) { |
929 | int old, avail = atomic_read(&ctx->reqs_available); | |
930 | ||
931 | do { | |
932 | if (avail < ctx->req_batch) | |
933 | goto out; | |
934 | ||
935 | old = avail; | |
936 | avail = atomic_cmpxchg(&ctx->reqs_available, | |
937 | avail, avail - ctx->req_batch); | |
938 | } while (avail != old); | |
939 | ||
940 | kcpu->reqs_available += ctx->req_batch; | |
941 | } | |
942 | ||
943 | ret = true; | |
944 | kcpu->reqs_available--; | |
945 | out: | |
263782c1 | 946 | local_irq_restore(flags); |
e1bdd5f2 KO |
947 | return ret; |
948 | } | |
949 | ||
d856f32a BL |
950 | /* refill_reqs_available |
951 | * Updates the reqs_available reference counts used for tracking the | |
952 | * number of free slots in the completion ring. This can be called | |
953 | * from aio_complete() (to optimistically update reqs_available) or | |
954 | * from aio_get_req() (the we're out of events case). It must be | |
955 | * called holding ctx->completion_lock. | |
956 | */ | |
957 | static void refill_reqs_available(struct kioctx *ctx, unsigned head, | |
958 | unsigned tail) | |
959 | { | |
960 | unsigned events_in_ring, completed; | |
961 | ||
962 | /* Clamp head since userland can write to it. */ | |
963 | head %= ctx->nr_events; | |
964 | if (head <= tail) | |
965 | events_in_ring = tail - head; | |
966 | else | |
967 | events_in_ring = ctx->nr_events - (head - tail); | |
968 | ||
969 | completed = ctx->completed_events; | |
970 | if (events_in_ring < completed) | |
971 | completed -= events_in_ring; | |
972 | else | |
973 | completed = 0; | |
974 | ||
975 | if (!completed) | |
976 | return; | |
977 | ||
978 | ctx->completed_events -= completed; | |
979 | put_reqs_available(ctx, completed); | |
980 | } | |
981 | ||
982 | /* user_refill_reqs_available | |
983 | * Called to refill reqs_available when aio_get_req() encounters an | |
984 | * out of space in the completion ring. | |
985 | */ | |
986 | static void user_refill_reqs_available(struct kioctx *ctx) | |
987 | { | |
988 | spin_lock_irq(&ctx->completion_lock); | |
989 | if (ctx->completed_events) { | |
990 | struct aio_ring *ring; | |
991 | unsigned head; | |
992 | ||
993 | /* Access of ring->head may race with aio_read_events_ring() | |
994 | * here, but that's okay since whether we read the old version | |
995 | * or the new version, and either will be valid. The important | |
996 | * part is that head cannot pass tail since we prevent | |
997 | * aio_complete() from updating tail by holding | |
998 | * ctx->completion_lock. Even if head is invalid, the check | |
999 | * against ctx->completed_events below will make sure we do the | |
1000 | * safe/right thing. | |
1001 | */ | |
1002 | ring = kmap_atomic(ctx->ring_pages[0]); | |
1003 | head = ring->head; | |
1004 | kunmap_atomic(ring); | |
1005 | ||
1006 | refill_reqs_available(ctx, head, ctx->tail); | |
1007 | } | |
1008 | ||
1009 | spin_unlock_irq(&ctx->completion_lock); | |
1010 | } | |
1011 | ||
432c7997 CH |
1012 | static bool get_reqs_available(struct kioctx *ctx) |
1013 | { | |
1014 | if (__get_reqs_available(ctx)) | |
1015 | return true; | |
1016 | user_refill_reqs_available(ctx); | |
1017 | return __get_reqs_available(ctx); | |
1018 | } | |
1019 | ||
1da177e4 | 1020 | /* aio_get_req |
57282d8f KO |
1021 | * Allocate a slot for an aio request. |
1022 | * Returns NULL if no requests are free. | |
b53119f1 LT |
1023 | * |
1024 | * The refcount is initialized to 2 - one for the async op completion, | |
1025 | * one for the synchronous code that does this. | |
1da177e4 | 1026 | */ |
04b2fa9f | 1027 | static inline struct aio_kiocb *aio_get_req(struct kioctx *ctx) |
1da177e4 | 1028 | { |
04b2fa9f | 1029 | struct aio_kiocb *req; |
a1c8eae7 | 1030 | |
2bc4ca9b | 1031 | req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL); |
1da177e4 | 1032 | if (unlikely(!req)) |
432c7997 | 1033 | return NULL; |
1da177e4 | 1034 | |
fa0ca2ae | 1035 | if (unlikely(!get_reqs_available(ctx))) { |
6af1c849 | 1036 | kmem_cache_free(kiocb_cachep, req); |
fa0ca2ae AV |
1037 | return NULL; |
1038 | } | |
1039 | ||
e34ecee2 | 1040 | percpu_ref_get(&ctx->reqs); |
2bc4ca9b | 1041 | req->ki_ctx = ctx; |
75321b50 | 1042 | INIT_LIST_HEAD(&req->ki_list); |
b53119f1 | 1043 | refcount_set(&req->ki_refcnt, 2); |
2bc4ca9b | 1044 | req->ki_eventfd = NULL; |
080d676d | 1045 | return req; |
1da177e4 LT |
1046 | } |
1047 | ||
d5470b59 | 1048 | static struct kioctx *lookup_ioctx(unsigned long ctx_id) |
1da177e4 | 1049 | { |
db446a08 | 1050 | struct aio_ring __user *ring = (void __user *)ctx_id; |
abf137dd | 1051 | struct mm_struct *mm = current->mm; |
65c24491 | 1052 | struct kioctx *ctx, *ret = NULL; |
db446a08 BL |
1053 | struct kioctx_table *table; |
1054 | unsigned id; | |
1055 | ||
1056 | if (get_user(id, &ring->id)) | |
1057 | return NULL; | |
1da177e4 | 1058 | |
abf137dd | 1059 | rcu_read_lock(); |
db446a08 | 1060 | table = rcu_dereference(mm->ioctx_table); |
abf137dd | 1061 | |
db446a08 BL |
1062 | if (!table || id >= table->nr) |
1063 | goto out; | |
1da177e4 | 1064 | |
a538e3ff | 1065 | id = array_index_nospec(id, table->nr); |
d0264c01 | 1066 | ctx = rcu_dereference(table->table[id]); |
f30d704f | 1067 | if (ctx && ctx->user_id == ctx_id) { |
baf10564 AV |
1068 | if (percpu_ref_tryget_live(&ctx->users)) |
1069 | ret = ctx; | |
db446a08 BL |
1070 | } |
1071 | out: | |
abf137dd | 1072 | rcu_read_unlock(); |
65c24491 | 1073 | return ret; |
1da177e4 LT |
1074 | } |
1075 | ||
b53119f1 LT |
1076 | static inline void iocb_destroy(struct aio_kiocb *iocb) |
1077 | { | |
74259703 AV |
1078 | if (iocb->ki_eventfd) |
1079 | eventfd_ctx_put(iocb->ki_eventfd); | |
b53119f1 LT |
1080 | if (iocb->ki_filp) |
1081 | fput(iocb->ki_filp); | |
1082 | percpu_ref_put(&iocb->ki_ctx->reqs); | |
1083 | kmem_cache_free(kiocb_cachep, iocb); | |
1084 | } | |
1085 | ||
1da177e4 LT |
1086 | /* aio_complete |
1087 | * Called when the io request on the given iocb is complete. | |
1da177e4 | 1088 | */ |
2bb874c0 | 1089 | static void aio_complete(struct aio_kiocb *iocb) |
1da177e4 LT |
1090 | { |
1091 | struct kioctx *ctx = iocb->ki_ctx; | |
1da177e4 | 1092 | struct aio_ring *ring; |
21b40200 | 1093 | struct io_event *ev_page, *event; |
d856f32a | 1094 | unsigned tail, pos, head; |
1da177e4 | 1095 | unsigned long flags; |
1da177e4 | 1096 | |
0460fef2 KO |
1097 | /* |
1098 | * Add a completion event to the ring buffer. Must be done holding | |
4b30f07e | 1099 | * ctx->completion_lock to prevent other code from messing with the tail |
0460fef2 KO |
1100 | * pointer since we might be called from irq context. |
1101 | */ | |
1102 | spin_lock_irqsave(&ctx->completion_lock, flags); | |
1103 | ||
58c85dc2 | 1104 | tail = ctx->tail; |
21b40200 KO |
1105 | pos = tail + AIO_EVENTS_OFFSET; |
1106 | ||
58c85dc2 | 1107 | if (++tail >= ctx->nr_events) |
4bf69b2a | 1108 | tail = 0; |
1da177e4 | 1109 | |
58c85dc2 | 1110 | ev_page = kmap_atomic(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]); |
21b40200 KO |
1111 | event = ev_page + pos % AIO_EVENTS_PER_PAGE; |
1112 | ||
a9339b78 | 1113 | *event = iocb->ki_res; |
1da177e4 | 1114 | |
21b40200 | 1115 | kunmap_atomic(ev_page); |
58c85dc2 | 1116 | flush_dcache_page(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]); |
21b40200 | 1117 | |
a9339b78 AV |
1118 | pr_debug("%p[%u]: %p: %p %Lx %Lx %Lx\n", ctx, tail, iocb, |
1119 | (void __user *)(unsigned long)iocb->ki_res.obj, | |
1120 | iocb->ki_res.data, iocb->ki_res.res, iocb->ki_res.res2); | |
1da177e4 LT |
1121 | |
1122 | /* after flagging the request as done, we | |
1123 | * must never even look at it again | |
1124 | */ | |
1125 | smp_wmb(); /* make event visible before updating tail */ | |
1126 | ||
58c85dc2 | 1127 | ctx->tail = tail; |
1da177e4 | 1128 | |
58c85dc2 | 1129 | ring = kmap_atomic(ctx->ring_pages[0]); |
d856f32a | 1130 | head = ring->head; |
21b40200 | 1131 | ring->tail = tail; |
e8e3c3d6 | 1132 | kunmap_atomic(ring); |
58c85dc2 | 1133 | flush_dcache_page(ctx->ring_pages[0]); |
1da177e4 | 1134 | |
d856f32a BL |
1135 | ctx->completed_events++; |
1136 | if (ctx->completed_events > 1) | |
1137 | refill_reqs_available(ctx, head, tail); | |
0460fef2 KO |
1138 | spin_unlock_irqrestore(&ctx->completion_lock, flags); |
1139 | ||
21b40200 | 1140 | pr_debug("added to ring %p at [%u]\n", iocb, tail); |
8d1c98b0 DL |
1141 | |
1142 | /* | |
1143 | * Check if the user asked us to deliver the result through an | |
1144 | * eventfd. The eventfd_signal() function is safe to be called | |
1145 | * from IRQ context. | |
1146 | */ | |
74259703 | 1147 | if (iocb->ki_eventfd) |
8d1c98b0 DL |
1148 | eventfd_signal(iocb->ki_eventfd, 1); |
1149 | ||
6cb2a210 QB |
1150 | /* |
1151 | * We have to order our ring_info tail store above and test | |
1152 | * of the wait list below outside the wait lock. This is | |
1153 | * like in wake_up_bit() where clearing a bit has to be | |
1154 | * ordered with the unlocked test. | |
1155 | */ | |
1156 | smp_mb(); | |
1157 | ||
1da177e4 LT |
1158 | if (waitqueue_active(&ctx->wait)) |
1159 | wake_up(&ctx->wait); | |
2bb874c0 AV |
1160 | } |
1161 | ||
1162 | static inline void iocb_put(struct aio_kiocb *iocb) | |
1163 | { | |
1164 | if (refcount_dec_and_test(&iocb->ki_refcnt)) { | |
1165 | aio_complete(iocb); | |
1166 | iocb_destroy(iocb); | |
1167 | } | |
1da177e4 LT |
1168 | } |
1169 | ||
2be4e7de | 1170 | /* aio_read_events_ring |
a31ad380 KO |
1171 | * Pull an event off of the ioctx's event ring. Returns the number of |
1172 | * events fetched | |
1da177e4 | 1173 | */ |
a31ad380 KO |
1174 | static long aio_read_events_ring(struct kioctx *ctx, |
1175 | struct io_event __user *event, long nr) | |
1da177e4 | 1176 | { |
1da177e4 | 1177 | struct aio_ring *ring; |
5ffac122 | 1178 | unsigned head, tail, pos; |
a31ad380 KO |
1179 | long ret = 0; |
1180 | int copy_ret; | |
1181 | ||
9c9ce763 DC |
1182 | /* |
1183 | * The mutex can block and wake us up and that will cause | |
1184 | * wait_event_interruptible_hrtimeout() to schedule without sleeping | |
1185 | * and repeat. This should be rare enough that it doesn't cause | |
1186 | * peformance issues. See the comment in read_events() for more detail. | |
1187 | */ | |
1188 | sched_annotate_sleep(); | |
58c85dc2 | 1189 | mutex_lock(&ctx->ring_lock); |
1da177e4 | 1190 | |
fa8a53c3 | 1191 | /* Access to ->ring_pages here is protected by ctx->ring_lock. */ |
58c85dc2 | 1192 | ring = kmap_atomic(ctx->ring_pages[0]); |
a31ad380 | 1193 | head = ring->head; |
5ffac122 | 1194 | tail = ring->tail; |
a31ad380 KO |
1195 | kunmap_atomic(ring); |
1196 | ||
2ff396be JM |
1197 | /* |
1198 | * Ensure that once we've read the current tail pointer, that | |
1199 | * we also see the events that were stored up to the tail. | |
1200 | */ | |
1201 | smp_rmb(); | |
1202 | ||
5ffac122 | 1203 | pr_debug("h%u t%u m%u\n", head, tail, ctx->nr_events); |
1da177e4 | 1204 | |
5ffac122 | 1205 | if (head == tail) |
1da177e4 LT |
1206 | goto out; |
1207 | ||
edfbbf38 BL |
1208 | head %= ctx->nr_events; |
1209 | tail %= ctx->nr_events; | |
1210 | ||
a31ad380 KO |
1211 | while (ret < nr) { |
1212 | long avail; | |
1213 | struct io_event *ev; | |
1214 | struct page *page; | |
1215 | ||
5ffac122 KO |
1216 | avail = (head <= tail ? tail : ctx->nr_events) - head; |
1217 | if (head == tail) | |
a31ad380 KO |
1218 | break; |
1219 | ||
a31ad380 | 1220 | pos = head + AIO_EVENTS_OFFSET; |
58c85dc2 | 1221 | page = ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]; |
a31ad380 KO |
1222 | pos %= AIO_EVENTS_PER_PAGE; |
1223 | ||
d2988bd4 AV |
1224 | avail = min(avail, nr - ret); |
1225 | avail = min_t(long, avail, AIO_EVENTS_PER_PAGE - pos); | |
1226 | ||
a31ad380 KO |
1227 | ev = kmap(page); |
1228 | copy_ret = copy_to_user(event + ret, ev + pos, | |
1229 | sizeof(*ev) * avail); | |
1230 | kunmap(page); | |
1231 | ||
1232 | if (unlikely(copy_ret)) { | |
1233 | ret = -EFAULT; | |
1234 | goto out; | |
1235 | } | |
1236 | ||
1237 | ret += avail; | |
1238 | head += avail; | |
58c85dc2 | 1239 | head %= ctx->nr_events; |
1da177e4 | 1240 | } |
1da177e4 | 1241 | |
58c85dc2 | 1242 | ring = kmap_atomic(ctx->ring_pages[0]); |
a31ad380 | 1243 | ring->head = head; |
91d80a84 | 1244 | kunmap_atomic(ring); |
58c85dc2 | 1245 | flush_dcache_page(ctx->ring_pages[0]); |
a31ad380 | 1246 | |
5ffac122 | 1247 | pr_debug("%li h%u t%u\n", ret, head, tail); |
a31ad380 | 1248 | out: |
58c85dc2 | 1249 | mutex_unlock(&ctx->ring_lock); |
a31ad380 | 1250 | |
1da177e4 LT |
1251 | return ret; |
1252 | } | |
1253 | ||
a31ad380 KO |
1254 | static bool aio_read_events(struct kioctx *ctx, long min_nr, long nr, |
1255 | struct io_event __user *event, long *i) | |
1da177e4 | 1256 | { |
a31ad380 | 1257 | long ret = aio_read_events_ring(ctx, event + *i, nr - *i); |
1da177e4 | 1258 | |
a31ad380 KO |
1259 | if (ret > 0) |
1260 | *i += ret; | |
1da177e4 | 1261 | |
a31ad380 KO |
1262 | if (unlikely(atomic_read(&ctx->dead))) |
1263 | ret = -EINVAL; | |
1da177e4 | 1264 | |
a31ad380 KO |
1265 | if (!*i) |
1266 | *i = ret; | |
1da177e4 | 1267 | |
a31ad380 | 1268 | return ret < 0 || *i >= min_nr; |
1da177e4 LT |
1269 | } |
1270 | ||
a31ad380 | 1271 | static long read_events(struct kioctx *ctx, long min_nr, long nr, |
1da177e4 | 1272 | struct io_event __user *event, |
fa2e62a5 | 1273 | ktime_t until) |
1da177e4 | 1274 | { |
a31ad380 | 1275 | long ret = 0; |
1da177e4 | 1276 | |
a31ad380 KO |
1277 | /* |
1278 | * Note that aio_read_events() is being called as the conditional - i.e. | |
1279 | * we're calling it after prepare_to_wait() has set task state to | |
1280 | * TASK_INTERRUPTIBLE. | |
1281 | * | |
1282 | * But aio_read_events() can block, and if it blocks it's going to flip | |
1283 | * the task state back to TASK_RUNNING. | |
1284 | * | |
1285 | * This should be ok, provided it doesn't flip the state back to | |
1286 | * TASK_RUNNING and return 0 too much - that causes us to spin. That | |
1287 | * will only happen if the mutex_lock() call blocks, and we then find | |
1288 | * the ringbuffer empty. So in practice we should be ok, but it's | |
1289 | * something to be aware of when touching this code. | |
1290 | */ | |
2456e855 | 1291 | if (until == 0) |
5f785de5 FZ |
1292 | aio_read_events(ctx, min_nr, nr, event, &ret); |
1293 | else | |
1294 | wait_event_interruptible_hrtimeout(ctx->wait, | |
1295 | aio_read_events(ctx, min_nr, nr, event, &ret), | |
1296 | until); | |
a31ad380 | 1297 | return ret; |
1da177e4 LT |
1298 | } |
1299 | ||
1da177e4 LT |
1300 | /* sys_io_setup: |
1301 | * Create an aio_context capable of receiving at least nr_events. | |
1302 | * ctxp must not point to an aio_context that already exists, and | |
1303 | * must be initialized to 0 prior to the call. On successful | |
1304 | * creation of the aio_context, *ctxp is filled in with the resulting | |
1305 | * handle. May fail with -EINVAL if *ctxp is not initialized, | |
1306 | * if the specified nr_events exceeds internal limits. May fail | |
1307 | * with -EAGAIN if the specified nr_events exceeds the user's limit | |
1308 | * of available events. May fail with -ENOMEM if insufficient kernel | |
1309 | * resources are available. May fail with -EFAULT if an invalid | |
1310 | * pointer is passed for ctxp. Will fail with -ENOSYS if not | |
1311 | * implemented. | |
1312 | */ | |
002c8976 | 1313 | SYSCALL_DEFINE2(io_setup, unsigned, nr_events, aio_context_t __user *, ctxp) |
1da177e4 LT |
1314 | { |
1315 | struct kioctx *ioctx = NULL; | |
1316 | unsigned long ctx; | |
1317 | long ret; | |
1318 | ||
1319 | ret = get_user(ctx, ctxp); | |
1320 | if (unlikely(ret)) | |
1321 | goto out; | |
1322 | ||
1323 | ret = -EINVAL; | |
d55b5fda | 1324 | if (unlikely(ctx || nr_events == 0)) { |
acd88d4e | 1325 | pr_debug("EINVAL: ctx %lu nr_events %u\n", |
d55b5fda | 1326 | ctx, nr_events); |
1da177e4 LT |
1327 | goto out; |
1328 | } | |
1329 | ||
1330 | ioctx = ioctx_alloc(nr_events); | |
1331 | ret = PTR_ERR(ioctx); | |
1332 | if (!IS_ERR(ioctx)) { | |
1333 | ret = put_user(ioctx->user_id, ctxp); | |
a2e1859a | 1334 | if (ret) |
e02ba72a | 1335 | kill_ioctx(current->mm, ioctx, NULL); |
723be6e3 | 1336 | percpu_ref_put(&ioctx->users); |
1da177e4 LT |
1337 | } |
1338 | ||
1339 | out: | |
1340 | return ret; | |
1341 | } | |
1342 | ||
c00d2c7e AV |
1343 | #ifdef CONFIG_COMPAT |
1344 | COMPAT_SYSCALL_DEFINE2(io_setup, unsigned, nr_events, u32 __user *, ctx32p) | |
1345 | { | |
1346 | struct kioctx *ioctx = NULL; | |
1347 | unsigned long ctx; | |
1348 | long ret; | |
1349 | ||
1350 | ret = get_user(ctx, ctx32p); | |
1351 | if (unlikely(ret)) | |
1352 | goto out; | |
1353 | ||
1354 | ret = -EINVAL; | |
1355 | if (unlikely(ctx || nr_events == 0)) { | |
1356 | pr_debug("EINVAL: ctx %lu nr_events %u\n", | |
1357 | ctx, nr_events); | |
1358 | goto out; | |
1359 | } | |
1360 | ||
1361 | ioctx = ioctx_alloc(nr_events); | |
1362 | ret = PTR_ERR(ioctx); | |
1363 | if (!IS_ERR(ioctx)) { | |
1364 | /* truncating is ok because it's a user address */ | |
1365 | ret = put_user((u32)ioctx->user_id, ctx32p); | |
1366 | if (ret) | |
1367 | kill_ioctx(current->mm, ioctx, NULL); | |
1368 | percpu_ref_put(&ioctx->users); | |
1369 | } | |
1370 | ||
1371 | out: | |
1372 | return ret; | |
1373 | } | |
1374 | #endif | |
1375 | ||
1da177e4 LT |
1376 | /* sys_io_destroy: |
1377 | * Destroy the aio_context specified. May cancel any outstanding | |
1378 | * AIOs and block on completion. Will fail with -ENOSYS if not | |
642b5123 | 1379 | * implemented. May fail with -EINVAL if the context pointed to |
1da177e4 LT |
1380 | * is invalid. |
1381 | */ | |
002c8976 | 1382 | SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx) |
1da177e4 LT |
1383 | { |
1384 | struct kioctx *ioctx = lookup_ioctx(ctx); | |
1385 | if (likely(NULL != ioctx)) { | |
dc48e56d | 1386 | struct ctx_rq_wait wait; |
fb2d4483 | 1387 | int ret; |
e02ba72a | 1388 | |
dc48e56d JA |
1389 | init_completion(&wait.comp); |
1390 | atomic_set(&wait.count, 1); | |
1391 | ||
e02ba72a AP |
1392 | /* Pass requests_done to kill_ioctx() where it can be set |
1393 | * in a thread-safe way. If we try to set it here then we have | |
1394 | * a race condition if two io_destroy() called simultaneously. | |
1395 | */ | |
dc48e56d | 1396 | ret = kill_ioctx(current->mm, ioctx, &wait); |
723be6e3 | 1397 | percpu_ref_put(&ioctx->users); |
e02ba72a AP |
1398 | |
1399 | /* Wait until all IO for the context are done. Otherwise kernel | |
1400 | * keep using user-space buffers even if user thinks the context | |
1401 | * is destroyed. | |
1402 | */ | |
fb2d4483 | 1403 | if (!ret) |
dc48e56d | 1404 | wait_for_completion(&wait.comp); |
e02ba72a | 1405 | |
fb2d4483 | 1406 | return ret; |
1da177e4 | 1407 | } |
acd88d4e | 1408 | pr_debug("EINVAL: invalid context id\n"); |
1da177e4 LT |
1409 | return -EINVAL; |
1410 | } | |
1411 | ||
3c96c7f4 AV |
1412 | static void aio_remove_iocb(struct aio_kiocb *iocb) |
1413 | { | |
1414 | struct kioctx *ctx = iocb->ki_ctx; | |
1415 | unsigned long flags; | |
1416 | ||
1417 | spin_lock_irqsave(&ctx->ctx_lock, flags); | |
1418 | list_del(&iocb->ki_list); | |
1419 | spin_unlock_irqrestore(&ctx->ctx_lock, flags); | |
1420 | } | |
1421 | ||
54843f87 CH |
1422 | static void aio_complete_rw(struct kiocb *kiocb, long res, long res2) |
1423 | { | |
1424 | struct aio_kiocb *iocb = container_of(kiocb, struct aio_kiocb, rw); | |
1425 | ||
3c96c7f4 AV |
1426 | if (!list_empty_careful(&iocb->ki_list)) |
1427 | aio_remove_iocb(iocb); | |
1428 | ||
54843f87 CH |
1429 | if (kiocb->ki_flags & IOCB_WRITE) { |
1430 | struct inode *inode = file_inode(kiocb->ki_filp); | |
1431 | ||
1432 | /* | |
1433 | * Tell lockdep we inherited freeze protection from submission | |
1434 | * thread. | |
1435 | */ | |
1436 | if (S_ISREG(inode->i_mode)) | |
1437 | __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE); | |
1438 | file_end_write(kiocb->ki_filp); | |
1439 | } | |
1440 | ||
2bb874c0 AV |
1441 | iocb->ki_res.res = res; |
1442 | iocb->ki_res.res2 = res2; | |
1443 | iocb_put(iocb); | |
54843f87 CH |
1444 | } |
1445 | ||
88a6f18b | 1446 | static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb) |
54843f87 CH |
1447 | { |
1448 | int ret; | |
1449 | ||
54843f87 | 1450 | req->ki_complete = aio_complete_rw; |
ec51f8ee | 1451 | req->private = NULL; |
54843f87 CH |
1452 | req->ki_pos = iocb->aio_offset; |
1453 | req->ki_flags = iocb_flags(req->ki_filp); | |
1454 | if (iocb->aio_flags & IOCB_FLAG_RESFD) | |
1455 | req->ki_flags |= IOCB_EVENTFD; | |
fc28724d | 1456 | req->ki_hint = ki_hint_validate(file_write_hint(req->ki_filp)); |
d9a08a9e AM |
1457 | if (iocb->aio_flags & IOCB_FLAG_IOPRIO) { |
1458 | /* | |
1459 | * If the IOCB_FLAG_IOPRIO flag of aio_flags is set, then | |
1460 | * aio_reqprio is interpreted as an I/O scheduling | |
1461 | * class and priority. | |
1462 | */ | |
1463 | ret = ioprio_check_cap(iocb->aio_reqprio); | |
1464 | if (ret) { | |
9a6d9a62 | 1465 | pr_debug("aio ioprio check cap error: %d\n", ret); |
84c4e1f8 | 1466 | return ret; |
d9a08a9e AM |
1467 | } |
1468 | ||
1469 | req->ki_ioprio = iocb->aio_reqprio; | |
1470 | } else | |
76dc8913 | 1471 | req->ki_ioprio = get_current_ioprio(); |
d9a08a9e | 1472 | |
54843f87 CH |
1473 | ret = kiocb_set_rw_flags(req, iocb->aio_rw_flags); |
1474 | if (unlikely(ret)) | |
84c4e1f8 | 1475 | return ret; |
154989e4 CH |
1476 | |
1477 | req->ki_flags &= ~IOCB_HIPRI; /* no one is going to poll for this I/O */ | |
1478 | return 0; | |
54843f87 CH |
1479 | } |
1480 | ||
87e5e6da JA |
1481 | static ssize_t aio_setup_rw(int rw, const struct iocb *iocb, |
1482 | struct iovec **iovec, bool vectored, bool compat, | |
1483 | struct iov_iter *iter) | |
eed4e51f | 1484 | { |
89319d31 CH |
1485 | void __user *buf = (void __user *)(uintptr_t)iocb->aio_buf; |
1486 | size_t len = iocb->aio_nbytes; | |
1487 | ||
1488 | if (!vectored) { | |
1489 | ssize_t ret = import_single_range(rw, buf, len, *iovec, iter); | |
1490 | *iovec = NULL; | |
1491 | return ret; | |
1492 | } | |
9d85cba7 JM |
1493 | #ifdef CONFIG_COMPAT |
1494 | if (compat) | |
89319d31 CH |
1495 | return compat_import_iovec(rw, buf, len, UIO_FASTIOV, iovec, |
1496 | iter); | |
9d85cba7 | 1497 | #endif |
89319d31 | 1498 | return import_iovec(rw, buf, len, UIO_FASTIOV, iovec, iter); |
eed4e51f BP |
1499 | } |
1500 | ||
9061d14a | 1501 | static inline void aio_rw_done(struct kiocb *req, ssize_t ret) |
89319d31 CH |
1502 | { |
1503 | switch (ret) { | |
1504 | case -EIOCBQUEUED: | |
9061d14a | 1505 | break; |
89319d31 CH |
1506 | case -ERESTARTSYS: |
1507 | case -ERESTARTNOINTR: | |
1508 | case -ERESTARTNOHAND: | |
1509 | case -ERESTART_RESTARTBLOCK: | |
1510 | /* | |
1511 | * There's no easy way to restart the syscall since other AIO's | |
1512 | * may be already running. Just fail this IO with EINTR. | |
1513 | */ | |
1514 | ret = -EINTR; | |
1515 | /*FALLTHRU*/ | |
1516 | default: | |
bc9bff61 | 1517 | req->ki_complete(req, ret, 0); |
89319d31 CH |
1518 | } |
1519 | } | |
1520 | ||
958c13ce | 1521 | static int aio_read(struct kiocb *req, const struct iocb *iocb, |
88a6f18b | 1522 | bool vectored, bool compat) |
1da177e4 | 1523 | { |
00fefb9c | 1524 | struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; |
293bc982 | 1525 | struct iov_iter iter; |
54843f87 | 1526 | struct file *file; |
958c13ce | 1527 | int ret; |
1da177e4 | 1528 | |
54843f87 CH |
1529 | ret = aio_prep_rw(req, iocb); |
1530 | if (ret) | |
1531 | return ret; | |
1532 | file = req->ki_filp; | |
89319d31 | 1533 | if (unlikely(!(file->f_mode & FMODE_READ))) |
84c4e1f8 | 1534 | return -EBADF; |
54843f87 | 1535 | ret = -EINVAL; |
89319d31 | 1536 | if (unlikely(!file->f_op->read_iter)) |
84c4e1f8 | 1537 | return -EINVAL; |
73a7075e | 1538 | |
89319d31 | 1539 | ret = aio_setup_rw(READ, iocb, &iovec, vectored, compat, &iter); |
87e5e6da | 1540 | if (ret < 0) |
84c4e1f8 | 1541 | return ret; |
89319d31 CH |
1542 | ret = rw_verify_area(READ, file, &req->ki_pos, iov_iter_count(&iter)); |
1543 | if (!ret) | |
9061d14a | 1544 | aio_rw_done(req, call_read_iter(file, req, &iter)); |
89319d31 CH |
1545 | kfree(iovec); |
1546 | return ret; | |
1547 | } | |
73a7075e | 1548 | |
958c13ce | 1549 | static int aio_write(struct kiocb *req, const struct iocb *iocb, |
88a6f18b | 1550 | bool vectored, bool compat) |
89319d31 | 1551 | { |
89319d31 CH |
1552 | struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; |
1553 | struct iov_iter iter; | |
54843f87 | 1554 | struct file *file; |
958c13ce | 1555 | int ret; |
41ef4eb8 | 1556 | |
54843f87 CH |
1557 | ret = aio_prep_rw(req, iocb); |
1558 | if (ret) | |
1559 | return ret; | |
1560 | file = req->ki_filp; | |
1561 | ||
89319d31 | 1562 | if (unlikely(!(file->f_mode & FMODE_WRITE))) |
84c4e1f8 | 1563 | return -EBADF; |
89319d31 | 1564 | if (unlikely(!file->f_op->write_iter)) |
84c4e1f8 | 1565 | return -EINVAL; |
1da177e4 | 1566 | |
89319d31 | 1567 | ret = aio_setup_rw(WRITE, iocb, &iovec, vectored, compat, &iter); |
87e5e6da | 1568 | if (ret < 0) |
84c4e1f8 | 1569 | return ret; |
89319d31 CH |
1570 | ret = rw_verify_area(WRITE, file, &req->ki_pos, iov_iter_count(&iter)); |
1571 | if (!ret) { | |
70fe2f48 | 1572 | /* |
92ce4728 | 1573 | * Open-code file_start_write here to grab freeze protection, |
54843f87 CH |
1574 | * which will be released by another thread in |
1575 | * aio_complete_rw(). Fool lockdep by telling it the lock got | |
1576 | * released so that it doesn't complain about the held lock when | |
1577 | * we return to userspace. | |
70fe2f48 | 1578 | */ |
92ce4728 CH |
1579 | if (S_ISREG(file_inode(file)->i_mode)) { |
1580 | __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, true); | |
a12f1ae6 | 1581 | __sb_writers_release(file_inode(file)->i_sb, SB_FREEZE_WRITE); |
92ce4728 CH |
1582 | } |
1583 | req->ki_flags |= IOCB_WRITE; | |
9061d14a | 1584 | aio_rw_done(req, call_write_iter(file, req, &iter)); |
41ef4eb8 | 1585 | } |
89319d31 CH |
1586 | kfree(iovec); |
1587 | return ret; | |
1da177e4 LT |
1588 | } |
1589 | ||
a3c0d439 CH |
1590 | static void aio_fsync_work(struct work_struct *work) |
1591 | { | |
2bb874c0 | 1592 | struct aio_kiocb *iocb = container_of(work, struct aio_kiocb, fsync.work); |
87e329bc | 1593 | const struct cred *old_cred = override_creds(iocb->fsync.creds); |
a3c0d439 | 1594 | |
2bb874c0 | 1595 | iocb->ki_res.res = vfs_fsync(iocb->fsync.file, iocb->fsync.datasync); |
87e329bc MS |
1596 | revert_creds(old_cred); |
1597 | put_cred(iocb->fsync.creds); | |
2bb874c0 | 1598 | iocb_put(iocb); |
a3c0d439 CH |
1599 | } |
1600 | ||
88a6f18b JA |
1601 | static int aio_fsync(struct fsync_iocb *req, const struct iocb *iocb, |
1602 | bool datasync) | |
a3c0d439 CH |
1603 | { |
1604 | if (unlikely(iocb->aio_buf || iocb->aio_offset || iocb->aio_nbytes || | |
1605 | iocb->aio_rw_flags)) | |
1606 | return -EINVAL; | |
a11e1d43 | 1607 | |
84c4e1f8 | 1608 | if (unlikely(!req->file->f_op->fsync)) |
a3c0d439 | 1609 | return -EINVAL; |
a3c0d439 | 1610 | |
87e329bc MS |
1611 | req->creds = prepare_creds(); |
1612 | if (!req->creds) | |
1613 | return -ENOMEM; | |
1614 | ||
a3c0d439 CH |
1615 | req->datasync = datasync; |
1616 | INIT_WORK(&req->work, aio_fsync_work); | |
1617 | schedule_work(&req->work); | |
9061d14a | 1618 | return 0; |
a3c0d439 CH |
1619 | } |
1620 | ||
f32a4b7d JA |
1621 | static void aio_poll_put_work(struct work_struct *work) |
1622 | { | |
1623 | struct poll_iocb *req = container_of(work, struct poll_iocb, work); | |
1624 | struct aio_kiocb *iocb = container_of(req, struct aio_kiocb, poll); | |
1625 | ||
1626 | iocb_put(iocb); | |
1627 | } | |
1628 | ||
bfe4037e CH |
1629 | static void aio_poll_complete_work(struct work_struct *work) |
1630 | { | |
1631 | struct poll_iocb *req = container_of(work, struct poll_iocb, work); | |
1632 | struct aio_kiocb *iocb = container_of(req, struct aio_kiocb, poll); | |
1633 | struct poll_table_struct pt = { ._key = req->events }; | |
1634 | struct kioctx *ctx = iocb->ki_ctx; | |
1635 | __poll_t mask = 0; | |
1636 | ||
1637 | if (!READ_ONCE(req->cancelled)) | |
1638 | mask = vfs_poll(req->file, &pt) & req->events; | |
1639 | ||
1640 | /* | |
1641 | * Note that ->ki_cancel callers also delete iocb from active_reqs after | |
1642 | * calling ->ki_cancel. We need the ctx_lock roundtrip here to | |
1643 | * synchronize with them. In the cancellation case the list_del_init | |
1644 | * itself is not actually needed, but harmless so we keep it in to | |
1645 | * avoid further branches in the fast path. | |
1646 | */ | |
1647 | spin_lock_irq(&ctx->ctx_lock); | |
1648 | if (!mask && !READ_ONCE(req->cancelled)) { | |
1649 | add_wait_queue(req->head, &req->wait); | |
1650 | spin_unlock_irq(&ctx->ctx_lock); | |
1651 | return; | |
1652 | } | |
1653 | list_del_init(&iocb->ki_list); | |
af5c72b1 AV |
1654 | iocb->ki_res.res = mangle_poll(mask); |
1655 | req->done = true; | |
bfe4037e CH |
1656 | spin_unlock_irq(&ctx->ctx_lock); |
1657 | ||
af5c72b1 | 1658 | iocb_put(iocb); |
bfe4037e CH |
1659 | } |
1660 | ||
1661 | /* assumes we are called with irqs disabled */ | |
1662 | static int aio_poll_cancel(struct kiocb *iocb) | |
1663 | { | |
1664 | struct aio_kiocb *aiocb = container_of(iocb, struct aio_kiocb, rw); | |
1665 | struct poll_iocb *req = &aiocb->poll; | |
1666 | ||
1667 | spin_lock(&req->head->lock); | |
1668 | WRITE_ONCE(req->cancelled, true); | |
1669 | if (!list_empty(&req->wait.entry)) { | |
1670 | list_del_init(&req->wait.entry); | |
1671 | schedule_work(&aiocb->poll.work); | |
1672 | } | |
1673 | spin_unlock(&req->head->lock); | |
1674 | ||
1675 | return 0; | |
1676 | } | |
1677 | ||
1678 | static int aio_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync, | |
1679 | void *key) | |
1680 | { | |
1681 | struct poll_iocb *req = container_of(wait, struct poll_iocb, wait); | |
e8693bcf | 1682 | struct aio_kiocb *iocb = container_of(req, struct aio_kiocb, poll); |
bfe4037e | 1683 | __poll_t mask = key_to_poll(key); |
d3d6a18d | 1684 | unsigned long flags; |
bfe4037e | 1685 | |
bfe4037e | 1686 | /* for instances that support it check for an event match first: */ |
af5c72b1 AV |
1687 | if (mask && !(mask & req->events)) |
1688 | return 0; | |
e8693bcf | 1689 | |
af5c72b1 AV |
1690 | list_del_init(&req->wait.entry); |
1691 | ||
1692 | if (mask && spin_trylock_irqsave(&iocb->ki_ctx->ctx_lock, flags)) { | |
f32a4b7d JA |
1693 | struct kioctx *ctx = iocb->ki_ctx; |
1694 | ||
d3d6a18d BVA |
1695 | /* |
1696 | * Try to complete the iocb inline if we can. Use | |
1697 | * irqsave/irqrestore because not all filesystems (e.g. fuse) | |
1698 | * call this function with IRQs disabled and because IRQs | |
1699 | * have to be disabled before ctx_lock is obtained. | |
1700 | */ | |
af5c72b1 AV |
1701 | list_del(&iocb->ki_list); |
1702 | iocb->ki_res.res = mangle_poll(mask); | |
1703 | req->done = true; | |
f32a4b7d JA |
1704 | if (iocb->ki_eventfd && eventfd_signal_count()) { |
1705 | iocb = NULL; | |
1706 | INIT_WORK(&req->work, aio_poll_put_work); | |
1707 | schedule_work(&req->work); | |
1708 | } | |
1709 | spin_unlock_irqrestore(&ctx->ctx_lock, flags); | |
1710 | if (iocb) | |
1711 | iocb_put(iocb); | |
af5c72b1 AV |
1712 | } else { |
1713 | schedule_work(&req->work); | |
e8693bcf | 1714 | } |
bfe4037e CH |
1715 | return 1; |
1716 | } | |
1717 | ||
1718 | struct aio_poll_table { | |
1719 | struct poll_table_struct pt; | |
1720 | struct aio_kiocb *iocb; | |
1721 | int error; | |
1722 | }; | |
1723 | ||
1724 | static void | |
1725 | aio_poll_queue_proc(struct file *file, struct wait_queue_head *head, | |
1726 | struct poll_table_struct *p) | |
1727 | { | |
1728 | struct aio_poll_table *pt = container_of(p, struct aio_poll_table, pt); | |
1729 | ||
1730 | /* multiple wait queues per file are not supported */ | |
1731 | if (unlikely(pt->iocb->poll.head)) { | |
1732 | pt->error = -EINVAL; | |
1733 | return; | |
1734 | } | |
1735 | ||
1736 | pt->error = 0; | |
1737 | pt->iocb->poll.head = head; | |
1738 | add_wait_queue(head, &pt->iocb->poll.wait); | |
1739 | } | |
1740 | ||
958c13ce | 1741 | static int aio_poll(struct aio_kiocb *aiocb, const struct iocb *iocb) |
bfe4037e CH |
1742 | { |
1743 | struct kioctx *ctx = aiocb->ki_ctx; | |
1744 | struct poll_iocb *req = &aiocb->poll; | |
1745 | struct aio_poll_table apt; | |
af5c72b1 | 1746 | bool cancel = false; |
bfe4037e CH |
1747 | __poll_t mask; |
1748 | ||
1749 | /* reject any unknown events outside the normal event mask. */ | |
1750 | if ((u16)iocb->aio_buf != iocb->aio_buf) | |
1751 | return -EINVAL; | |
1752 | /* reject fields that are not defined for poll */ | |
1753 | if (iocb->aio_offset || iocb->aio_nbytes || iocb->aio_rw_flags) | |
1754 | return -EINVAL; | |
1755 | ||
1756 | INIT_WORK(&req->work, aio_poll_complete_work); | |
1757 | req->events = demangle_poll(iocb->aio_buf) | EPOLLERR | EPOLLHUP; | |
bfe4037e | 1758 | |
2bc4ca9b | 1759 | req->head = NULL; |
af5c72b1 | 1760 | req->done = false; |
2bc4ca9b JA |
1761 | req->cancelled = false; |
1762 | ||
bfe4037e CH |
1763 | apt.pt._qproc = aio_poll_queue_proc; |
1764 | apt.pt._key = req->events; | |
1765 | apt.iocb = aiocb; | |
1766 | apt.error = -EINVAL; /* same as no support for IOCB_CMD_POLL */ | |
1767 | ||
1768 | /* initialized the list so that we can do list_empty checks */ | |
1769 | INIT_LIST_HEAD(&req->wait.entry); | |
1770 | init_waitqueue_func_entry(&req->wait, aio_poll_wake); | |
1771 | ||
bfe4037e | 1772 | mask = vfs_poll(req->file, &apt.pt) & req->events; |
bfe4037e | 1773 | spin_lock_irq(&ctx->ctx_lock); |
af5c72b1 AV |
1774 | if (likely(req->head)) { |
1775 | spin_lock(&req->head->lock); | |
1776 | if (unlikely(list_empty(&req->wait.entry))) { | |
1777 | if (apt.error) | |
1778 | cancel = true; | |
1779 | apt.error = 0; | |
1780 | mask = 0; | |
1781 | } | |
1782 | if (mask || apt.error) { | |
1783 | list_del_init(&req->wait.entry); | |
1784 | } else if (cancel) { | |
1785 | WRITE_ONCE(req->cancelled, true); | |
1786 | } else if (!req->done) { /* actually waiting for an event */ | |
1787 | list_add_tail(&aiocb->ki_list, &ctx->active_reqs); | |
1788 | aiocb->ki_cancel = aio_poll_cancel; | |
1789 | } | |
1790 | spin_unlock(&req->head->lock); | |
1791 | } | |
1792 | if (mask) { /* no async, we'd stolen it */ | |
1793 | aiocb->ki_res.res = mangle_poll(mask); | |
bfe4037e | 1794 | apt.error = 0; |
bfe4037e | 1795 | } |
bfe4037e | 1796 | spin_unlock_irq(&ctx->ctx_lock); |
bfe4037e | 1797 | if (mask) |
af5c72b1 AV |
1798 | iocb_put(aiocb); |
1799 | return apt.error; | |
bfe4037e CH |
1800 | } |
1801 | ||
88a6f18b | 1802 | static int __io_submit_one(struct kioctx *ctx, const struct iocb *iocb, |
7316b49c AV |
1803 | struct iocb __user *user_iocb, struct aio_kiocb *req, |
1804 | bool compat) | |
1da177e4 | 1805 | { |
84c4e1f8 | 1806 | req->ki_filp = fget(iocb->aio_fildes); |
84c4e1f8 | 1807 | if (unlikely(!req->ki_filp)) |
7316b49c | 1808 | return -EBADF; |
84c4e1f8 | 1809 | |
88a6f18b | 1810 | if (iocb->aio_flags & IOCB_FLAG_RESFD) { |
74259703 | 1811 | struct eventfd_ctx *eventfd; |
9c3060be DL |
1812 | /* |
1813 | * If the IOCB_FLAG_RESFD flag of aio_flags is set, get an | |
1814 | * instance of the file* now. The file descriptor must be | |
1815 | * an eventfd() fd, and will be signaled for each completed | |
1816 | * event using the eventfd_signal() function. | |
1817 | */ | |
74259703 | 1818 | eventfd = eventfd_ctx_fdget(iocb->aio_resfd); |
7316b49c | 1819 | if (IS_ERR(eventfd)) |
18bfb9c6 | 1820 | return PTR_ERR(eventfd); |
7316b49c | 1821 | |
74259703 | 1822 | req->ki_eventfd = eventfd; |
9830f4be GR |
1823 | } |
1824 | ||
7316b49c | 1825 | if (unlikely(put_user(KIOCB_KEY, &user_iocb->aio_key))) { |
caf4167a | 1826 | pr_debug("EFAULT: aio_key\n"); |
7316b49c | 1827 | return -EFAULT; |
1da177e4 LT |
1828 | } |
1829 | ||
a9339b78 AV |
1830 | req->ki_res.obj = (u64)(unsigned long)user_iocb; |
1831 | req->ki_res.data = iocb->aio_data; | |
1832 | req->ki_res.res = 0; | |
1833 | req->ki_res.res2 = 0; | |
1da177e4 | 1834 | |
88a6f18b | 1835 | switch (iocb->aio_lio_opcode) { |
89319d31 | 1836 | case IOCB_CMD_PREAD: |
7316b49c | 1837 | return aio_read(&req->rw, iocb, false, compat); |
89319d31 | 1838 | case IOCB_CMD_PWRITE: |
7316b49c | 1839 | return aio_write(&req->rw, iocb, false, compat); |
89319d31 | 1840 | case IOCB_CMD_PREADV: |
7316b49c | 1841 | return aio_read(&req->rw, iocb, true, compat); |
89319d31 | 1842 | case IOCB_CMD_PWRITEV: |
7316b49c | 1843 | return aio_write(&req->rw, iocb, true, compat); |
a3c0d439 | 1844 | case IOCB_CMD_FSYNC: |
7316b49c | 1845 | return aio_fsync(&req->fsync, iocb, false); |
a3c0d439 | 1846 | case IOCB_CMD_FDSYNC: |
7316b49c | 1847 | return aio_fsync(&req->fsync, iocb, true); |
bfe4037e | 1848 | case IOCB_CMD_POLL: |
7316b49c | 1849 | return aio_poll(req, iocb); |
89319d31 | 1850 | default: |
88a6f18b | 1851 | pr_debug("invalid aio operation %d\n", iocb->aio_lio_opcode); |
7316b49c | 1852 | return -EINVAL; |
89319d31 | 1853 | } |
1da177e4 LT |
1854 | } |
1855 | ||
88a6f18b JA |
1856 | static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, |
1857 | bool compat) | |
1858 | { | |
7316b49c | 1859 | struct aio_kiocb *req; |
88a6f18b | 1860 | struct iocb iocb; |
7316b49c | 1861 | int err; |
88a6f18b JA |
1862 | |
1863 | if (unlikely(copy_from_user(&iocb, user_iocb, sizeof(iocb)))) | |
1864 | return -EFAULT; | |
1865 | ||
7316b49c AV |
1866 | /* enforce forwards compatibility on users */ |
1867 | if (unlikely(iocb.aio_reserved2)) { | |
1868 | pr_debug("EINVAL: reserve field set\n"); | |
1869 | return -EINVAL; | |
1870 | } | |
1871 | ||
1872 | /* prevent overflows */ | |
1873 | if (unlikely( | |
1874 | (iocb.aio_buf != (unsigned long)iocb.aio_buf) || | |
1875 | (iocb.aio_nbytes != (size_t)iocb.aio_nbytes) || | |
1876 | ((ssize_t)iocb.aio_nbytes < 0) | |
1877 | )) { | |
1878 | pr_debug("EINVAL: overflow check\n"); | |
1879 | return -EINVAL; | |
1880 | } | |
1881 | ||
1882 | req = aio_get_req(ctx); | |
1883 | if (unlikely(!req)) | |
1884 | return -EAGAIN; | |
1885 | ||
1886 | err = __io_submit_one(ctx, &iocb, user_iocb, req, compat); | |
1887 | ||
1888 | /* Done with the synchronous reference */ | |
1889 | iocb_put(req); | |
1890 | ||
1891 | /* | |
1892 | * If err is 0, we'd either done aio_complete() ourselves or have | |
1893 | * arranged for that to be done asynchronously. Anything non-zero | |
1894 | * means that we need to destroy req ourselves. | |
1895 | */ | |
1896 | if (unlikely(err)) { | |
1897 | iocb_destroy(req); | |
1898 | put_reqs_available(ctx, 1); | |
1899 | } | |
1900 | return err; | |
88a6f18b JA |
1901 | } |
1902 | ||
67ba049f AV |
1903 | /* sys_io_submit: |
1904 | * Queue the nr iocbs pointed to by iocbpp for processing. Returns | |
1905 | * the number of iocbs queued. May return -EINVAL if the aio_context | |
1906 | * specified by ctx_id is invalid, if nr is < 0, if the iocb at | |
1907 | * *iocbpp[0] is not properly initialized, if the operation specified | |
1908 | * is invalid for the file descriptor in the iocb. May fail with | |
1909 | * -EFAULT if any of the data structures point to invalid data. May | |
1910 | * fail with -EBADF if the file descriptor specified in the first | |
1911 | * iocb is invalid. May fail with -EAGAIN if insufficient resources | |
1912 | * are available to queue any iocbs. Will return 0 if nr is 0. Will | |
1913 | * fail with -ENOSYS if not implemented. | |
1914 | */ | |
1915 | SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr, | |
1916 | struct iocb __user * __user *, iocbpp) | |
1da177e4 LT |
1917 | { |
1918 | struct kioctx *ctx; | |
1919 | long ret = 0; | |
080d676d | 1920 | int i = 0; |
9f5b9425 | 1921 | struct blk_plug plug; |
1da177e4 LT |
1922 | |
1923 | if (unlikely(nr < 0)) | |
1924 | return -EINVAL; | |
1925 | ||
1da177e4 LT |
1926 | ctx = lookup_ioctx(ctx_id); |
1927 | if (unlikely(!ctx)) { | |
caf4167a | 1928 | pr_debug("EINVAL: invalid context id\n"); |
1da177e4 LT |
1929 | return -EINVAL; |
1930 | } | |
1931 | ||
1da92779 AV |
1932 | if (nr > ctx->nr_events) |
1933 | nr = ctx->nr_events; | |
1934 | ||
a79d40e9 JA |
1935 | if (nr > AIO_PLUG_THRESHOLD) |
1936 | blk_start_plug(&plug); | |
67ba049f | 1937 | for (i = 0; i < nr; i++) { |
1da177e4 | 1938 | struct iocb __user *user_iocb; |
1da177e4 | 1939 | |
67ba049f | 1940 | if (unlikely(get_user(user_iocb, iocbpp + i))) { |
1da177e4 LT |
1941 | ret = -EFAULT; |
1942 | break; | |
1943 | } | |
1944 | ||
67ba049f | 1945 | ret = io_submit_one(ctx, user_iocb, false); |
1da177e4 LT |
1946 | if (ret) |
1947 | break; | |
1948 | } | |
a79d40e9 JA |
1949 | if (nr > AIO_PLUG_THRESHOLD) |
1950 | blk_finish_plug(&plug); | |
1da177e4 | 1951 | |
723be6e3 | 1952 | percpu_ref_put(&ctx->users); |
1da177e4 LT |
1953 | return i ? i : ret; |
1954 | } | |
1955 | ||
c00d2c7e | 1956 | #ifdef CONFIG_COMPAT |
c00d2c7e | 1957 | COMPAT_SYSCALL_DEFINE3(io_submit, compat_aio_context_t, ctx_id, |
67ba049f | 1958 | int, nr, compat_uptr_t __user *, iocbpp) |
c00d2c7e | 1959 | { |
67ba049f AV |
1960 | struct kioctx *ctx; |
1961 | long ret = 0; | |
1962 | int i = 0; | |
1963 | struct blk_plug plug; | |
c00d2c7e AV |
1964 | |
1965 | if (unlikely(nr < 0)) | |
1966 | return -EINVAL; | |
1967 | ||
67ba049f AV |
1968 | ctx = lookup_ioctx(ctx_id); |
1969 | if (unlikely(!ctx)) { | |
1970 | pr_debug("EINVAL: invalid context id\n"); | |
1971 | return -EINVAL; | |
1972 | } | |
1973 | ||
1da92779 AV |
1974 | if (nr > ctx->nr_events) |
1975 | nr = ctx->nr_events; | |
1976 | ||
a79d40e9 JA |
1977 | if (nr > AIO_PLUG_THRESHOLD) |
1978 | blk_start_plug(&plug); | |
67ba049f AV |
1979 | for (i = 0; i < nr; i++) { |
1980 | compat_uptr_t user_iocb; | |
1981 | ||
1982 | if (unlikely(get_user(user_iocb, iocbpp + i))) { | |
1983 | ret = -EFAULT; | |
1984 | break; | |
1985 | } | |
1986 | ||
1987 | ret = io_submit_one(ctx, compat_ptr(user_iocb), true); | |
1988 | if (ret) | |
1989 | break; | |
1990 | } | |
a79d40e9 JA |
1991 | if (nr > AIO_PLUG_THRESHOLD) |
1992 | blk_finish_plug(&plug); | |
67ba049f AV |
1993 | |
1994 | percpu_ref_put(&ctx->users); | |
1995 | return i ? i : ret; | |
c00d2c7e AV |
1996 | } |
1997 | #endif | |
1998 | ||
1da177e4 LT |
1999 | /* sys_io_cancel: |
2000 | * Attempts to cancel an iocb previously passed to io_submit. If | |
2001 | * the operation is successfully cancelled, the resulting event is | |
2002 | * copied into the memory pointed to by result without being placed | |
2003 | * into the completion queue and 0 is returned. May fail with | |
2004 | * -EFAULT if any of the data structures pointed to are invalid. | |
2005 | * May fail with -EINVAL if aio_context specified by ctx_id is | |
2006 | * invalid. May fail with -EAGAIN if the iocb specified was not | |
2007 | * cancelled. Will fail with -ENOSYS if not implemented. | |
2008 | */ | |
002c8976 HC |
2009 | SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb, |
2010 | struct io_event __user *, result) | |
1da177e4 | 2011 | { |
1da177e4 | 2012 | struct kioctx *ctx; |
04b2fa9f | 2013 | struct aio_kiocb *kiocb; |
888933f8 | 2014 | int ret = -EINVAL; |
1da177e4 | 2015 | u32 key; |
a9339b78 | 2016 | u64 obj = (u64)(unsigned long)iocb; |
1da177e4 | 2017 | |
f3a2752a | 2018 | if (unlikely(get_user(key, &iocb->aio_key))) |
1da177e4 | 2019 | return -EFAULT; |
f3a2752a CH |
2020 | if (unlikely(key != KIOCB_KEY)) |
2021 | return -EINVAL; | |
1da177e4 LT |
2022 | |
2023 | ctx = lookup_ioctx(ctx_id); | |
2024 | if (unlikely(!ctx)) | |
2025 | return -EINVAL; | |
2026 | ||
2027 | spin_lock_irq(&ctx->ctx_lock); | |
833f4154 AV |
2028 | /* TODO: use a hash or array, this sucks. */ |
2029 | list_for_each_entry(kiocb, &ctx->active_reqs, ki_list) { | |
a9339b78 | 2030 | if (kiocb->ki_res.obj == obj) { |
833f4154 AV |
2031 | ret = kiocb->ki_cancel(&kiocb->rw); |
2032 | list_del_init(&kiocb->ki_list); | |
2033 | break; | |
2034 | } | |
888933f8 | 2035 | } |
1da177e4 LT |
2036 | spin_unlock_irq(&ctx->ctx_lock); |
2037 | ||
906b973c | 2038 | if (!ret) { |
bec68faa KO |
2039 | /* |
2040 | * The result argument is no longer used - the io_event is | |
2041 | * always delivered via the ring buffer. -EINPROGRESS indicates | |
2042 | * cancellation is progress: | |
906b973c | 2043 | */ |
bec68faa | 2044 | ret = -EINPROGRESS; |
906b973c | 2045 | } |
1da177e4 | 2046 | |
723be6e3 | 2047 | percpu_ref_put(&ctx->users); |
1da177e4 LT |
2048 | |
2049 | return ret; | |
2050 | } | |
2051 | ||
fa2e62a5 DD |
2052 | static long do_io_getevents(aio_context_t ctx_id, |
2053 | long min_nr, | |
2054 | long nr, | |
2055 | struct io_event __user *events, | |
2056 | struct timespec64 *ts) | |
2057 | { | |
2058 | ktime_t until = ts ? timespec64_to_ktime(*ts) : KTIME_MAX; | |
2059 | struct kioctx *ioctx = lookup_ioctx(ctx_id); | |
2060 | long ret = -EINVAL; | |
2061 | ||
2062 | if (likely(ioctx)) { | |
2063 | if (likely(min_nr <= nr && min_nr >= 0)) | |
2064 | ret = read_events(ioctx, min_nr, nr, events, until); | |
2065 | percpu_ref_put(&ioctx->users); | |
2066 | } | |
2067 | ||
2068 | return ret; | |
2069 | } | |
2070 | ||
1da177e4 LT |
2071 | /* io_getevents: |
2072 | * Attempts to read at least min_nr events and up to nr events from | |
642b5123 ST |
2073 | * the completion queue for the aio_context specified by ctx_id. If |
2074 | * it succeeds, the number of read events is returned. May fail with | |
2075 | * -EINVAL if ctx_id is invalid, if min_nr is out of range, if nr is | |
2076 | * out of range, if timeout is out of range. May fail with -EFAULT | |
2077 | * if any of the memory specified is invalid. May return 0 or | |
2078 | * < min_nr if the timeout specified by timeout has elapsed | |
2079 | * before sufficient events are available, where timeout == NULL | |
2080 | * specifies an infinite timeout. Note that the timeout pointed to by | |
6900807c | 2081 | * timeout is relative. Will fail with -ENOSYS if not implemented. |
1da177e4 | 2082 | */ |
7a35397f DD |
2083 | #if !defined(CONFIG_64BIT_TIME) || defined(CONFIG_64BIT) |
2084 | ||
002c8976 HC |
2085 | SYSCALL_DEFINE5(io_getevents, aio_context_t, ctx_id, |
2086 | long, min_nr, | |
2087 | long, nr, | |
2088 | struct io_event __user *, events, | |
7a35397f | 2089 | struct __kernel_timespec __user *, timeout) |
1da177e4 | 2090 | { |
fa2e62a5 | 2091 | struct timespec64 ts; |
7a074e96 CH |
2092 | int ret; |
2093 | ||
2094 | if (timeout && unlikely(get_timespec64(&ts, timeout))) | |
2095 | return -EFAULT; | |
2096 | ||
2097 | ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL); | |
2098 | if (!ret && signal_pending(current)) | |
2099 | ret = -EINTR; | |
2100 | return ret; | |
2101 | } | |
1da177e4 | 2102 | |
7a35397f DD |
2103 | #endif |
2104 | ||
9ba546c0 CH |
2105 | struct __aio_sigset { |
2106 | const sigset_t __user *sigmask; | |
2107 | size_t sigsetsize; | |
2108 | }; | |
2109 | ||
7a074e96 CH |
2110 | SYSCALL_DEFINE6(io_pgetevents, |
2111 | aio_context_t, ctx_id, | |
2112 | long, min_nr, | |
2113 | long, nr, | |
2114 | struct io_event __user *, events, | |
7a35397f | 2115 | struct __kernel_timespec __user *, timeout, |
7a074e96 CH |
2116 | const struct __aio_sigset __user *, usig) |
2117 | { | |
2118 | struct __aio_sigset ksig = { NULL, }; | |
7a074e96 | 2119 | struct timespec64 ts; |
97abc889 | 2120 | bool interrupted; |
7a074e96 CH |
2121 | int ret; |
2122 | ||
2123 | if (timeout && unlikely(get_timespec64(&ts, timeout))) | |
2124 | return -EFAULT; | |
2125 | ||
2126 | if (usig && copy_from_user(&ksig, usig, sizeof(ksig))) | |
2127 | return -EFAULT; | |
2128 | ||
b772434b | 2129 | ret = set_user_sigmask(ksig.sigmask, ksig.sigsetsize); |
7a35397f DD |
2130 | if (ret) |
2131 | return ret; | |
7a074e96 CH |
2132 | |
2133 | ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL); | |
97abc889 ON |
2134 | |
2135 | interrupted = signal_pending(current); | |
b772434b | 2136 | restore_saved_sigmask_unless(interrupted); |
97abc889 | 2137 | if (interrupted && !ret) |
7a35397f | 2138 | ret = -ERESTARTNOHAND; |
7a074e96 | 2139 | |
7a35397f DD |
2140 | return ret; |
2141 | } | |
2142 | ||
2143 | #if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT) | |
2144 | ||
2145 | SYSCALL_DEFINE6(io_pgetevents_time32, | |
2146 | aio_context_t, ctx_id, | |
2147 | long, min_nr, | |
2148 | long, nr, | |
2149 | struct io_event __user *, events, | |
2150 | struct old_timespec32 __user *, timeout, | |
2151 | const struct __aio_sigset __user *, usig) | |
2152 | { | |
2153 | struct __aio_sigset ksig = { NULL, }; | |
7a35397f | 2154 | struct timespec64 ts; |
97abc889 | 2155 | bool interrupted; |
7a35397f DD |
2156 | int ret; |
2157 | ||
2158 | if (timeout && unlikely(get_old_timespec32(&ts, timeout))) | |
2159 | return -EFAULT; | |
2160 | ||
2161 | if (usig && copy_from_user(&ksig, usig, sizeof(ksig))) | |
2162 | return -EFAULT; | |
2163 | ||
ded653cc | 2164 | |
b772434b | 2165 | ret = set_user_sigmask(ksig.sigmask, ksig.sigsetsize); |
ded653cc DD |
2166 | if (ret) |
2167 | return ret; | |
7a074e96 CH |
2168 | |
2169 | ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL); | |
97abc889 ON |
2170 | |
2171 | interrupted = signal_pending(current); | |
b772434b | 2172 | restore_saved_sigmask_unless(interrupted); |
97abc889 | 2173 | if (interrupted && !ret) |
854a6ed5 | 2174 | ret = -ERESTARTNOHAND; |
fa2e62a5 | 2175 | |
7a074e96 | 2176 | return ret; |
1da177e4 | 2177 | } |
c00d2c7e | 2178 | |
7a35397f DD |
2179 | #endif |
2180 | ||
2181 | #if defined(CONFIG_COMPAT_32BIT_TIME) | |
2182 | ||
8dabe724 AB |
2183 | SYSCALL_DEFINE5(io_getevents_time32, __u32, ctx_id, |
2184 | __s32, min_nr, | |
2185 | __s32, nr, | |
2186 | struct io_event __user *, events, | |
2187 | struct old_timespec32 __user *, timeout) | |
c00d2c7e | 2188 | { |
fa2e62a5 | 2189 | struct timespec64 t; |
7a074e96 CH |
2190 | int ret; |
2191 | ||
9afc5eee | 2192 | if (timeout && get_old_timespec32(&t, timeout)) |
7a074e96 CH |
2193 | return -EFAULT; |
2194 | ||
2195 | ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &t : NULL); | |
2196 | if (!ret && signal_pending(current)) | |
2197 | ret = -EINTR; | |
2198 | return ret; | |
2199 | } | |
2200 | ||
7a35397f DD |
2201 | #endif |
2202 | ||
2203 | #ifdef CONFIG_COMPAT | |
c00d2c7e | 2204 | |
7a074e96 | 2205 | struct __compat_aio_sigset { |
97eba80f | 2206 | compat_uptr_t sigmask; |
7a074e96 CH |
2207 | compat_size_t sigsetsize; |
2208 | }; | |
2209 | ||
7a35397f DD |
2210 | #if defined(CONFIG_COMPAT_32BIT_TIME) |
2211 | ||
7a074e96 CH |
2212 | COMPAT_SYSCALL_DEFINE6(io_pgetevents, |
2213 | compat_aio_context_t, ctx_id, | |
2214 | compat_long_t, min_nr, | |
2215 | compat_long_t, nr, | |
2216 | struct io_event __user *, events, | |
9afc5eee | 2217 | struct old_timespec32 __user *, timeout, |
7a074e96 CH |
2218 | const struct __compat_aio_sigset __user *, usig) |
2219 | { | |
97eba80f | 2220 | struct __compat_aio_sigset ksig = { 0, }; |
7a074e96 | 2221 | struct timespec64 t; |
97abc889 | 2222 | bool interrupted; |
7a074e96 CH |
2223 | int ret; |
2224 | ||
9afc5eee | 2225 | if (timeout && get_old_timespec32(&t, timeout)) |
7a074e96 CH |
2226 | return -EFAULT; |
2227 | ||
2228 | if (usig && copy_from_user(&ksig, usig, sizeof(ksig))) | |
2229 | return -EFAULT; | |
2230 | ||
97eba80f | 2231 | ret = set_compat_user_sigmask(compat_ptr(ksig.sigmask), ksig.sigsetsize); |
ded653cc DD |
2232 | if (ret) |
2233 | return ret; | |
c00d2c7e | 2234 | |
7a074e96 | 2235 | ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &t : NULL); |
97abc889 ON |
2236 | |
2237 | interrupted = signal_pending(current); | |
b772434b | 2238 | restore_saved_sigmask_unless(interrupted); |
97abc889 | 2239 | if (interrupted && !ret) |
854a6ed5 | 2240 | ret = -ERESTARTNOHAND; |
fa2e62a5 | 2241 | |
7a074e96 | 2242 | return ret; |
c00d2c7e | 2243 | } |
7a35397f DD |
2244 | |
2245 | #endif | |
2246 | ||
2247 | COMPAT_SYSCALL_DEFINE6(io_pgetevents_time64, | |
2248 | compat_aio_context_t, ctx_id, | |
2249 | compat_long_t, min_nr, | |
2250 | compat_long_t, nr, | |
2251 | struct io_event __user *, events, | |
2252 | struct __kernel_timespec __user *, timeout, | |
2253 | const struct __compat_aio_sigset __user *, usig) | |
2254 | { | |
97eba80f | 2255 | struct __compat_aio_sigset ksig = { 0, }; |
7a35397f | 2256 | struct timespec64 t; |
97abc889 | 2257 | bool interrupted; |
7a35397f DD |
2258 | int ret; |
2259 | ||
2260 | if (timeout && get_timespec64(&t, timeout)) | |
2261 | return -EFAULT; | |
2262 | ||
2263 | if (usig && copy_from_user(&ksig, usig, sizeof(ksig))) | |
2264 | return -EFAULT; | |
2265 | ||
97eba80f | 2266 | ret = set_compat_user_sigmask(compat_ptr(ksig.sigmask), ksig.sigsetsize); |
7a35397f DD |
2267 | if (ret) |
2268 | return ret; | |
2269 | ||
2270 | ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &t : NULL); | |
97abc889 ON |
2271 | |
2272 | interrupted = signal_pending(current); | |
b772434b | 2273 | restore_saved_sigmask_unless(interrupted); |
97abc889 | 2274 | if (interrupted && !ret) |
7a35397f | 2275 | ret = -ERESTARTNOHAND; |
fa2e62a5 | 2276 | |
7a074e96 | 2277 | return ret; |
c00d2c7e AV |
2278 | } |
2279 | #endif |