Eric Lee / smarc-ti-linux-kernel

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Commit cdecbb336e64b8a846bf97c5a275dc94fdb1083d

Authored by Linus Torvalds
2 parents 4e02370f64 9c9ce763b1
Exists in ti-lsk-linux-4.1.y and in 10 other branches dlt-processor-sdk-linux-03.00.00.04, processor-sdk-linux-02.00.01, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04

Merge git://git.kvack.org/~bcrl/aio-fixes 

Pull aio nested sleep annotation from Ben LaHaise,

* git://git.kvack.org/~bcrl/aio-fixes:
  aio: annotate aio_read_event_ring for sleep patterns

Showing 1 changed file Inline Diff

1 /* 1 /*
2 * An async IO implementation for Linux 2 * An async IO implementation for Linux
3 * Written by Benjamin LaHaise <bcrl@kvack.org> 3 * Written by Benjamin LaHaise <bcrl@kvack.org>
4 * 4 *
5 * Implements an efficient asynchronous io interface. 5 * Implements an efficient asynchronous io interface.
6 * 6 *
7 * Copyright 2000, 2001, 2002 Red Hat, Inc. All Rights Reserved. 7 * Copyright 2000, 2001, 2002 Red Hat, Inc. All Rights Reserved.
8 * 8 *
9 * See ../COPYING for licensing terms. 9 * See ../COPYING for licensing terms.
10 */ 10 */
11 #define pr_fmt(fmt) "%s: " fmt, __func__ 11 #define pr_fmt(fmt) "%s: " fmt, __func__
12 12
13 #include <linux/kernel.h> 13 #include <linux/kernel.h>
14 #include <linux/init.h> 14 #include <linux/init.h>
15 #include <linux/errno.h> 15 #include <linux/errno.h>
16 #include <linux/time.h> 16 #include <linux/time.h>
17 #include <linux/aio_abi.h> 17 #include <linux/aio_abi.h>
18 #include <linux/export.h> 18 #include <linux/export.h>
19 #include <linux/syscalls.h> 19 #include <linux/syscalls.h>
20 #include <linux/backing-dev.h> 20 #include <linux/backing-dev.h>
21 #include <linux/uio.h> 21 #include <linux/uio.h>
22 22
23 #include <linux/sched.h> 23 #include <linux/sched.h>
24 #include <linux/fs.h> 24 #include <linux/fs.h>
25 #include <linux/file.h> 25 #include <linux/file.h>
26 #include <linux/mm.h> 26 #include <linux/mm.h>
27 #include <linux/mman.h> 27 #include <linux/mman.h>
28 #include <linux/mmu_context.h> 28 #include <linux/mmu_context.h>
29 #include <linux/percpu.h> 29 #include <linux/percpu.h>
30 #include <linux/slab.h> 30 #include <linux/slab.h>
31 #include <linux/timer.h> 31 #include <linux/timer.h>
32 #include <linux/aio.h> 32 #include <linux/aio.h>
33 #include <linux/highmem.h> 33 #include <linux/highmem.h>
34 #include <linux/workqueue.h> 34 #include <linux/workqueue.h>
35 #include <linux/security.h> 35 #include <linux/security.h>
36 #include <linux/eventfd.h> 36 #include <linux/eventfd.h>
37 #include <linux/blkdev.h> 37 #include <linux/blkdev.h>
38 #include <linux/compat.h> 38 #include <linux/compat.h>
39 #include <linux/migrate.h> 39 #include <linux/migrate.h>
40 #include <linux/ramfs.h> 40 #include <linux/ramfs.h>
41 #include <linux/percpu-refcount.h> 41 #include <linux/percpu-refcount.h>
42 #include <linux/mount.h> 42 #include <linux/mount.h>
43 43
44 #include <asm/kmap_types.h> 44 #include <asm/kmap_types.h>
45 #include <asm/uaccess.h> 45 #include <asm/uaccess.h>
46 46
47 #include "internal.h" 47 #include "internal.h"
48 48
49 #define AIO_RING_MAGIC 0xa10a10a1 49 #define AIO_RING_MAGIC 0xa10a10a1
50 #define AIO_RING_COMPAT_FEATURES 1 50 #define AIO_RING_COMPAT_FEATURES 1
51 #define AIO_RING_INCOMPAT_FEATURES 0 51 #define AIO_RING_INCOMPAT_FEATURES 0
52 struct aio_ring { 52 struct aio_ring {
53 unsigned id; /* kernel internal index number */ 53 unsigned id; /* kernel internal index number */
54 unsigned nr; /* number of io_events */ 54 unsigned nr; /* number of io_events */
55 unsigned head; /* Written to by userland or under ring_lock 55 unsigned head; /* Written to by userland or under ring_lock
56 * mutex by aio_read_events_ring(). */ 56 * mutex by aio_read_events_ring(). */
57 unsigned tail; 57 unsigned tail;
58 58
59 unsigned magic; 59 unsigned magic;
60 unsigned compat_features; 60 unsigned compat_features;
61 unsigned incompat_features; 61 unsigned incompat_features;
62 unsigned header_length; /* size of aio_ring */ 62 unsigned header_length; /* size of aio_ring */
63 63
64 64
65 struct io_event io_events[0]; 65 struct io_event io_events[0];
66 }; /* 128 bytes + ring size */ 66 }; /* 128 bytes + ring size */
67 67
68 #define AIO_RING_PAGES 8 68 #define AIO_RING_PAGES 8
69 69
70 struct kioctx_table { 70 struct kioctx_table {
71 struct rcu_head rcu; 71 struct rcu_head rcu;
72 unsigned nr; 72 unsigned nr;
73 struct kioctx *table[]; 73 struct kioctx *table[];
74 }; 74 };
75 75
76 struct kioctx_cpu { 76 struct kioctx_cpu {
77 unsigned reqs_available; 77 unsigned reqs_available;
78 }; 78 };
79 79
80 struct kioctx { 80 struct kioctx {
81 struct percpu_ref users; 81 struct percpu_ref users;
82 atomic_t dead; 82 atomic_t dead;
83 83
84 struct percpu_ref reqs; 84 struct percpu_ref reqs;
85 85
86 unsigned long user_id; 86 unsigned long user_id;
87 87
88 struct __percpu kioctx_cpu *cpu; 88 struct __percpu kioctx_cpu *cpu;
89 89
90 /* 90 /*
91 * For percpu reqs_available, number of slots we move to/from global 91 * For percpu reqs_available, number of slots we move to/from global
92 * counter at a time: 92 * counter at a time:
93 */ 93 */
94 unsigned req_batch; 94 unsigned req_batch;
95 /* 95 /*
96 * This is what userspace passed to io_setup(), it's not used for 96 * This is what userspace passed to io_setup(), it's not used for
97 * anything but counting against the global max_reqs quota. 97 * anything but counting against the global max_reqs quota.
98 * 98 *
99 * The real limit is nr_events - 1, which will be larger (see 99 * The real limit is nr_events - 1, which will be larger (see
100 * aio_setup_ring()) 100 * aio_setup_ring())
101 */ 101 */
102 unsigned max_reqs; 102 unsigned max_reqs;
103 103
104 /* Size of ringbuffer, in units of struct io_event */ 104 /* Size of ringbuffer, in units of struct io_event */
105 unsigned nr_events; 105 unsigned nr_events;
106 106
107 unsigned long mmap_base; 107 unsigned long mmap_base;
108 unsigned long mmap_size; 108 unsigned long mmap_size;
109 109
110 struct page **ring_pages; 110 struct page **ring_pages;
111 long nr_pages; 111 long nr_pages;
112 112
113 struct work_struct free_work; 113 struct work_struct free_work;
114 114
115 /* 115 /*
116 * signals when all in-flight requests are done 116 * signals when all in-flight requests are done
117 */ 117 */
118 struct completion *requests_done; 118 struct completion *requests_done;
119 119
120 struct { 120 struct {
121 /* 121 /*
122 * This counts the number of available slots in the ringbuffer, 122 * This counts the number of available slots in the ringbuffer,
123 * so we avoid overflowing it: it's decremented (if positive) 123 * so we avoid overflowing it: it's decremented (if positive)
124 * when allocating a kiocb and incremented when the resulting 124 * when allocating a kiocb and incremented when the resulting
125 * io_event is pulled off the ringbuffer. 125 * io_event is pulled off the ringbuffer.
126 * 126 *
127 * We batch accesses to it with a percpu version. 127 * We batch accesses to it with a percpu version.
128 */ 128 */
129 atomic_t reqs_available; 129 atomic_t reqs_available;
130 } ____cacheline_aligned_in_smp; 130 } ____cacheline_aligned_in_smp;
131 131
132 struct { 132 struct {
133 spinlock_t ctx_lock; 133 spinlock_t ctx_lock;
134 struct list_head active_reqs; /* used for cancellation */ 134 struct list_head active_reqs; /* used for cancellation */
135 } ____cacheline_aligned_in_smp; 135 } ____cacheline_aligned_in_smp;
136 136
137 struct { 137 struct {
138 struct mutex ring_lock; 138 struct mutex ring_lock;
139 wait_queue_head_t wait; 139 wait_queue_head_t wait;
140 } ____cacheline_aligned_in_smp; 140 } ____cacheline_aligned_in_smp;
141 141
142 struct { 142 struct {
143 unsigned tail; 143 unsigned tail;
144 unsigned completed_events; 144 unsigned completed_events;
145 spinlock_t completion_lock; 145 spinlock_t completion_lock;
146 } ____cacheline_aligned_in_smp; 146 } ____cacheline_aligned_in_smp;
147 147
148 struct page *internal_pages[AIO_RING_PAGES]; 148 struct page *internal_pages[AIO_RING_PAGES];
149 struct file *aio_ring_file; 149 struct file *aio_ring_file;
150 150
151 unsigned id; 151 unsigned id;
152 }; 152 };
153 153
154 /*------ sysctl variables----*/ 154 /*------ sysctl variables----*/
155 static DEFINE_SPINLOCK(aio_nr_lock); 155 static DEFINE_SPINLOCK(aio_nr_lock);
156 unsigned long aio_nr; /* current system wide number of aio requests */ 156 unsigned long aio_nr; /* current system wide number of aio requests */
157 unsigned long aio_max_nr = 0x10000; /* system wide maximum number of aio requests */ 157 unsigned long aio_max_nr = 0x10000; /* system wide maximum number of aio requests */
158 /*----end sysctl variables---*/ 158 /*----end sysctl variables---*/
159 159
160 static struct kmem_cache *kiocb_cachep; 160 static struct kmem_cache *kiocb_cachep;
161 static struct kmem_cache *kioctx_cachep; 161 static struct kmem_cache *kioctx_cachep;
162 162
163 static struct vfsmount *aio_mnt; 163 static struct vfsmount *aio_mnt;
164 164
165 static const struct file_operations aio_ring_fops; 165 static const struct file_operations aio_ring_fops;
166 static const struct address_space_operations aio_ctx_aops; 166 static const struct address_space_operations aio_ctx_aops;
167 167
168 /* Backing dev info for aio fs. 168 /* Backing dev info for aio fs.
169 * -no dirty page accounting or writeback happens 169 * -no dirty page accounting or writeback happens
170 */ 170 */
171 static struct backing_dev_info aio_fs_backing_dev_info = { 171 static struct backing_dev_info aio_fs_backing_dev_info = {
172 .name = "aiofs", 172 .name = "aiofs",
173 .state = 0, 173 .state = 0,
174 .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_MAP_COPY, 174 .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_MAP_COPY,
175 }; 175 };
176 176
177 static struct file *aio_private_file(struct kioctx *ctx, loff_t nr_pages) 177 static struct file *aio_private_file(struct kioctx *ctx, loff_t nr_pages)
178 { 178 {
179 struct qstr this = QSTR_INIT("[aio]", 5); 179 struct qstr this = QSTR_INIT("[aio]", 5);
180 struct file *file; 180 struct file *file;
181 struct path path; 181 struct path path;
182 struct inode *inode = alloc_anon_inode(aio_mnt->mnt_sb); 182 struct inode *inode = alloc_anon_inode(aio_mnt->mnt_sb);
183 if (IS_ERR(inode)) 183 if (IS_ERR(inode))
184 return ERR_CAST(inode); 184 return ERR_CAST(inode);
185 185
186 inode->i_mapping->a_ops = &aio_ctx_aops; 186 inode->i_mapping->a_ops = &aio_ctx_aops;
187 inode->i_mapping->private_data = ctx; 187 inode->i_mapping->private_data = ctx;
188 inode->i_mapping->backing_dev_info = &aio_fs_backing_dev_info; 188 inode->i_mapping->backing_dev_info = &aio_fs_backing_dev_info;
189 inode->i_size = PAGE_SIZE * nr_pages; 189 inode->i_size = PAGE_SIZE * nr_pages;
190 190
191 path.dentry = d_alloc_pseudo(aio_mnt->mnt_sb, &this); 191 path.dentry = d_alloc_pseudo(aio_mnt->mnt_sb, &this);
192 if (!path.dentry) { 192 if (!path.dentry) {
193 iput(inode); 193 iput(inode);
194 return ERR_PTR(-ENOMEM); 194 return ERR_PTR(-ENOMEM);
195 } 195 }
196 path.mnt = mntget(aio_mnt); 196 path.mnt = mntget(aio_mnt);
197 197
198 d_instantiate(path.dentry, inode); 198 d_instantiate(path.dentry, inode);
199 file = alloc_file(&path, FMODE_READ | FMODE_WRITE, &aio_ring_fops); 199 file = alloc_file(&path, FMODE_READ | FMODE_WRITE, &aio_ring_fops);
200 if (IS_ERR(file)) { 200 if (IS_ERR(file)) {
201 path_put(&path); 201 path_put(&path);
202 return file; 202 return file;
203 } 203 }
204 204
205 file->f_flags = O_RDWR; 205 file->f_flags = O_RDWR;
206 return file; 206 return file;
207 } 207 }
208 208
209 static struct dentry *aio_mount(struct file_system_type *fs_type, 209 static struct dentry *aio_mount(struct file_system_type *fs_type,
210 int flags, const char *dev_name, void *data) 210 int flags, const char *dev_name, void *data)
211 { 211 {
212 static const struct dentry_operations ops = { 212 static const struct dentry_operations ops = {
213 .d_dname = simple_dname, 213 .d_dname = simple_dname,
214 }; 214 };
215 return mount_pseudo(fs_type, "aio:", NULL, &ops, AIO_RING_MAGIC); 215 return mount_pseudo(fs_type, "aio:", NULL, &ops, AIO_RING_MAGIC);
216 } 216 }
217 217
218 /* aio_setup 218 /* aio_setup
219 * Creates the slab caches used by the aio routines, panic on 219 * Creates the slab caches used by the aio routines, panic on
220 * failure as this is done early during the boot sequence. 220 * failure as this is done early during the boot sequence.
221 */ 221 */
222 static int __init aio_setup(void) 222 static int __init aio_setup(void)
223 { 223 {
224 static struct file_system_type aio_fs = { 224 static struct file_system_type aio_fs = {
225 .name = "aio", 225 .name = "aio",
226 .mount = aio_mount, 226 .mount = aio_mount,
227 .kill_sb = kill_anon_super, 227 .kill_sb = kill_anon_super,
228 }; 228 };
229 aio_mnt = kern_mount(&aio_fs); 229 aio_mnt = kern_mount(&aio_fs);
230 if (IS_ERR(aio_mnt)) 230 if (IS_ERR(aio_mnt))
231 panic("Failed to create aio fs mount."); 231 panic("Failed to create aio fs mount.");
232 232
233 if (bdi_init(&aio_fs_backing_dev_info)) 233 if (bdi_init(&aio_fs_backing_dev_info))
234 panic("Failed to init aio fs backing dev info."); 234 panic("Failed to init aio fs backing dev info.");
235 235
236 kiocb_cachep = KMEM_CACHE(kiocb, SLAB_HWCACHE_ALIGN|SLAB_PANIC); 236 kiocb_cachep = KMEM_CACHE(kiocb, SLAB_HWCACHE_ALIGN|SLAB_PANIC);
237 kioctx_cachep = KMEM_CACHE(kioctx,SLAB_HWCACHE_ALIGN|SLAB_PANIC); 237 kioctx_cachep = KMEM_CACHE(kioctx,SLAB_HWCACHE_ALIGN|SLAB_PANIC);
238 238
239 pr_debug("sizeof(struct page) = %zu\n", sizeof(struct page)); 239 pr_debug("sizeof(struct page) = %zu\n", sizeof(struct page));
240 240
241 return 0; 241 return 0;
242 } 242 }
243 __initcall(aio_setup); 243 __initcall(aio_setup);
244 244
245 static void put_aio_ring_file(struct kioctx *ctx) 245 static void put_aio_ring_file(struct kioctx *ctx)
246 { 246 {
247 struct file *aio_ring_file = ctx->aio_ring_file; 247 struct file *aio_ring_file = ctx->aio_ring_file;
248 if (aio_ring_file) { 248 if (aio_ring_file) {
249 truncate_setsize(aio_ring_file->f_inode, 0); 249 truncate_setsize(aio_ring_file->f_inode, 0);
250 250
251 /* Prevent further access to the kioctx from migratepages */ 251 /* Prevent further access to the kioctx from migratepages */
252 spin_lock(&aio_ring_file->f_inode->i_mapping->private_lock); 252 spin_lock(&aio_ring_file->f_inode->i_mapping->private_lock);
253 aio_ring_file->f_inode->i_mapping->private_data = NULL; 253 aio_ring_file->f_inode->i_mapping->private_data = NULL;
254 ctx->aio_ring_file = NULL; 254 ctx->aio_ring_file = NULL;
255 spin_unlock(&aio_ring_file->f_inode->i_mapping->private_lock); 255 spin_unlock(&aio_ring_file->f_inode->i_mapping->private_lock);
256 256
257 fput(aio_ring_file); 257 fput(aio_ring_file);
258 } 258 }
259 } 259 }
260 260
261 static void aio_free_ring(struct kioctx *ctx) 261 static void aio_free_ring(struct kioctx *ctx)
262 { 262 {
263 int i; 263 int i;
264 264
265 /* Disconnect the kiotx from the ring file. This prevents future 265 /* Disconnect the kiotx from the ring file. This prevents future
266 * accesses to the kioctx from page migration. 266 * accesses to the kioctx from page migration.
267 */ 267 */
268 put_aio_ring_file(ctx); 268 put_aio_ring_file(ctx);
269 269
270 for (i = 0; i < ctx->nr_pages; i++) { 270 for (i = 0; i < ctx->nr_pages; i++) {
271 struct page *page; 271 struct page *page;
272 pr_debug("pid(%d) [%d] page->count=%d\n", current->pid, i, 272 pr_debug("pid(%d) [%d] page->count=%d\n", current->pid, i,
273 page_count(ctx->ring_pages[i])); 273 page_count(ctx->ring_pages[i]));
274 page = ctx->ring_pages[i]; 274 page = ctx->ring_pages[i];
275 if (!page) 275 if (!page)
276 continue; 276 continue;
277 ctx->ring_pages[i] = NULL; 277 ctx->ring_pages[i] = NULL;
278 put_page(page); 278 put_page(page);
279 } 279 }
280 280
281 if (ctx->ring_pages && ctx->ring_pages != ctx->internal_pages) { 281 if (ctx->ring_pages && ctx->ring_pages != ctx->internal_pages) {
282 kfree(ctx->ring_pages); 282 kfree(ctx->ring_pages);
283 ctx->ring_pages = NULL; 283 ctx->ring_pages = NULL;
284 } 284 }
285 } 285 }
286 286
287 static int aio_ring_mmap(struct file *file, struct vm_area_struct *vma) 287 static int aio_ring_mmap(struct file *file, struct vm_area_struct *vma)
288 { 288 {
289 vma->vm_flags |= VM_DONTEXPAND; 289 vma->vm_flags |= VM_DONTEXPAND;
290 vma->vm_ops = &generic_file_vm_ops; 290 vma->vm_ops = &generic_file_vm_ops;
291 return 0; 291 return 0;
292 } 292 }
293 293
294 static void aio_ring_remap(struct file *file, struct vm_area_struct *vma) 294 static void aio_ring_remap(struct file *file, struct vm_area_struct *vma)
295 { 295 {
296 struct mm_struct *mm = vma->vm_mm; 296 struct mm_struct *mm = vma->vm_mm;
297 struct kioctx_table *table; 297 struct kioctx_table *table;
298 int i; 298 int i;
299 299
300 spin_lock(&mm->ioctx_lock); 300 spin_lock(&mm->ioctx_lock);
301 rcu_read_lock(); 301 rcu_read_lock();
302 table = rcu_dereference(mm->ioctx_table); 302 table = rcu_dereference(mm->ioctx_table);
303 for (i = 0; i < table->nr; i++) { 303 for (i = 0; i < table->nr; i++) {
304 struct kioctx *ctx; 304 struct kioctx *ctx;
305 305
306 ctx = table->table[i]; 306 ctx = table->table[i];
307 if (ctx && ctx->aio_ring_file == file) { 307 if (ctx && ctx->aio_ring_file == file) {
308 ctx->user_id = ctx->mmap_base = vma->vm_start; 308 ctx->user_id = ctx->mmap_base = vma->vm_start;
309 break; 309 break;
310 } 310 }
311 } 311 }
312 312
313 rcu_read_unlock(); 313 rcu_read_unlock();
314 spin_unlock(&mm->ioctx_lock); 314 spin_unlock(&mm->ioctx_lock);
315 } 315 }
316 316
317 static const struct file_operations aio_ring_fops = { 317 static const struct file_operations aio_ring_fops = {
318 .mmap = aio_ring_mmap, 318 .mmap = aio_ring_mmap,
319 .mremap = aio_ring_remap, 319 .mremap = aio_ring_remap,
320 }; 320 };
321 321
322 #if IS_ENABLED(CONFIG_MIGRATION) 322 #if IS_ENABLED(CONFIG_MIGRATION)
323 static int aio_migratepage(struct address_space *mapping, struct page *new, 323 static int aio_migratepage(struct address_space *mapping, struct page *new,
324 struct page *old, enum migrate_mode mode) 324 struct page *old, enum migrate_mode mode)
325 { 325 {
326 struct kioctx *ctx; 326 struct kioctx *ctx;
327 unsigned long flags; 327 unsigned long flags;
328 pgoff_t idx; 328 pgoff_t idx;
329 int rc; 329 int rc;
330 330
331 rc = 0; 331 rc = 0;
332 332
333 /* mapping->private_lock here protects against the kioctx teardown. */ 333 /* mapping->private_lock here protects against the kioctx teardown. */
334 spin_lock(&mapping->private_lock); 334 spin_lock(&mapping->private_lock);
335 ctx = mapping->private_data; 335 ctx = mapping->private_data;
336 if (!ctx) { 336 if (!ctx) {
337 rc = -EINVAL; 337 rc = -EINVAL;
338 goto out; 338 goto out;
339 } 339 }
340 340
341 /* The ring_lock mutex. The prevents aio_read_events() from writing 341 /* The ring_lock mutex. The prevents aio_read_events() from writing
342 * to the ring's head, and prevents page migration from mucking in 342 * to the ring's head, and prevents page migration from mucking in
343 * a partially initialized kiotx. 343 * a partially initialized kiotx.
344 */ 344 */
345 if (!mutex_trylock(&ctx->ring_lock)) { 345 if (!mutex_trylock(&ctx->ring_lock)) {
346 rc = -EAGAIN; 346 rc = -EAGAIN;
347 goto out; 347 goto out;
348 } 348 }
349 349
350 idx = old->index; 350 idx = old->index;
351 if (idx < (pgoff_t)ctx->nr_pages) { 351 if (idx < (pgoff_t)ctx->nr_pages) {
352 /* Make sure the old page hasn't already been changed */ 352 /* Make sure the old page hasn't already been changed */
353 if (ctx->ring_pages[idx] != old) 353 if (ctx->ring_pages[idx] != old)
354 rc = -EAGAIN; 354 rc = -EAGAIN;
355 } else 355 } else
356 rc = -EINVAL; 356 rc = -EINVAL;
357 357
358 if (rc != 0) 358 if (rc != 0)
359 goto out_unlock; 359 goto out_unlock;
360 360
361 /* Writeback must be complete */ 361 /* Writeback must be complete */
362 BUG_ON(PageWriteback(old)); 362 BUG_ON(PageWriteback(old));
363 get_page(new); 363 get_page(new);
364 364
365 rc = migrate_page_move_mapping(mapping, new, old, NULL, mode, 1); 365 rc = migrate_page_move_mapping(mapping, new, old, NULL, mode, 1);
366 if (rc != MIGRATEPAGE_SUCCESS) { 366 if (rc != MIGRATEPAGE_SUCCESS) {
367 put_page(new); 367 put_page(new);
368 goto out_unlock; 368 goto out_unlock;
369 } 369 }
370 370
371 /* Take completion_lock to prevent other writes to the ring buffer 371 /* Take completion_lock to prevent other writes to the ring buffer
372 * while the old page is copied to the new. This prevents new 372 * while the old page is copied to the new. This prevents new
373 * events from being lost. 373 * events from being lost.
374 */ 374 */
375 spin_lock_irqsave(&ctx->completion_lock, flags); 375 spin_lock_irqsave(&ctx->completion_lock, flags);
376 migrate_page_copy(new, old); 376 migrate_page_copy(new, old);
377 BUG_ON(ctx->ring_pages[idx] != old); 377 BUG_ON(ctx->ring_pages[idx] != old);
378 ctx->ring_pages[idx] = new; 378 ctx->ring_pages[idx] = new;
379 spin_unlock_irqrestore(&ctx->completion_lock, flags); 379 spin_unlock_irqrestore(&ctx->completion_lock, flags);
380 380
381 /* The old page is no longer accessible. */ 381 /* The old page is no longer accessible. */
382 put_page(old); 382 put_page(old);
383 383
384 out_unlock: 384 out_unlock:
385 mutex_unlock(&ctx->ring_lock); 385 mutex_unlock(&ctx->ring_lock);
386 out: 386 out:
387 spin_unlock(&mapping->private_lock); 387 spin_unlock(&mapping->private_lock);
388 return rc; 388 return rc;
389 } 389 }
390 #endif 390 #endif
391 391
392 static const struct address_space_operations aio_ctx_aops = { 392 static const struct address_space_operations aio_ctx_aops = {
393 .set_page_dirty = __set_page_dirty_no_writeback, 393 .set_page_dirty = __set_page_dirty_no_writeback,
394 #if IS_ENABLED(CONFIG_MIGRATION) 394 #if IS_ENABLED(CONFIG_MIGRATION)
395 .migratepage = aio_migratepage, 395 .migratepage = aio_migratepage,
396 #endif 396 #endif
397 }; 397 };
398 398
399 static int aio_setup_ring(struct kioctx *ctx) 399 static int aio_setup_ring(struct kioctx *ctx)
400 { 400 {
401 struct aio_ring *ring; 401 struct aio_ring *ring;
402 unsigned nr_events = ctx->max_reqs; 402 unsigned nr_events = ctx->max_reqs;
403 struct mm_struct *mm = current->mm; 403 struct mm_struct *mm = current->mm;
404 unsigned long size, unused; 404 unsigned long size, unused;
405 int nr_pages; 405 int nr_pages;
406 int i; 406 int i;
407 struct file *file; 407 struct file *file;
408 408
409 /* Compensate for the ring buffer's head/tail overlap entry */ 409 /* Compensate for the ring buffer's head/tail overlap entry */
410 nr_events += 2; /* 1 is required, 2 for good luck */ 410 nr_events += 2; /* 1 is required, 2 for good luck */
411 411
412 size = sizeof(struct aio_ring); 412 size = sizeof(struct aio_ring);
413 size += sizeof(struct io_event) * nr_events; 413 size += sizeof(struct io_event) * nr_events;
414 414
415 nr_pages = PFN_UP(size); 415 nr_pages = PFN_UP(size);
416 if (nr_pages < 0) 416 if (nr_pages < 0)
417 return -EINVAL; 417 return -EINVAL;
418 418
419 file = aio_private_file(ctx, nr_pages); 419 file = aio_private_file(ctx, nr_pages);
420 if (IS_ERR(file)) { 420 if (IS_ERR(file)) {
421 ctx->aio_ring_file = NULL; 421 ctx->aio_ring_file = NULL;
422 return -ENOMEM; 422 return -ENOMEM;
423 } 423 }
424 424
425 ctx->aio_ring_file = file; 425 ctx->aio_ring_file = file;
426 nr_events = (PAGE_SIZE * nr_pages - sizeof(struct aio_ring)) 426 nr_events = (PAGE_SIZE * nr_pages - sizeof(struct aio_ring))
427 / sizeof(struct io_event); 427 / sizeof(struct io_event);
428 428
429 ctx->ring_pages = ctx->internal_pages; 429 ctx->ring_pages = ctx->internal_pages;
430 if (nr_pages > AIO_RING_PAGES) { 430 if (nr_pages > AIO_RING_PAGES) {
431 ctx->ring_pages = kcalloc(nr_pages, sizeof(struct page *), 431 ctx->ring_pages = kcalloc(nr_pages, sizeof(struct page *),
432 GFP_KERNEL); 432 GFP_KERNEL);
433 if (!ctx->ring_pages) { 433 if (!ctx->ring_pages) {
434 put_aio_ring_file(ctx); 434 put_aio_ring_file(ctx);
435 return -ENOMEM; 435 return -ENOMEM;
436 } 436 }
437 } 437 }
438 438
439 for (i = 0; i < nr_pages; i++) { 439 for (i = 0; i < nr_pages; i++) {
440 struct page *page; 440 struct page *page;
441 page = find_or_create_page(file->f_inode->i_mapping, 441 page = find_or_create_page(file->f_inode->i_mapping,
442 i, GFP_HIGHUSER | __GFP_ZERO); 442 i, GFP_HIGHUSER | __GFP_ZERO);
443 if (!page) 443 if (!page)
444 break; 444 break;
445 pr_debug("pid(%d) page[%d]->count=%d\n", 445 pr_debug("pid(%d) page[%d]->count=%d\n",
446 current->pid, i, page_count(page)); 446 current->pid, i, page_count(page));
447 SetPageUptodate(page); 447 SetPageUptodate(page);
448 unlock_page(page); 448 unlock_page(page);
449 449
450 ctx->ring_pages[i] = page; 450 ctx->ring_pages[i] = page;
451 } 451 }
452 ctx->nr_pages = i; 452 ctx->nr_pages = i;
453 453
454 if (unlikely(i != nr_pages)) { 454 if (unlikely(i != nr_pages)) {
455 aio_free_ring(ctx); 455 aio_free_ring(ctx);
456 return -ENOMEM; 456 return -ENOMEM;
457 } 457 }
458 458
459 ctx->mmap_size = nr_pages * PAGE_SIZE; 459 ctx->mmap_size = nr_pages * PAGE_SIZE;
460 pr_debug("attempting mmap of %lu bytes\n", ctx->mmap_size); 460 pr_debug("attempting mmap of %lu bytes\n", ctx->mmap_size);
461 461
462 down_write(&mm->mmap_sem); 462 down_write(&mm->mmap_sem);
463 ctx->mmap_base = do_mmap_pgoff(ctx->aio_ring_file, 0, ctx->mmap_size, 463 ctx->mmap_base = do_mmap_pgoff(ctx->aio_ring_file, 0, ctx->mmap_size,
464 PROT_READ | PROT_WRITE, 464 PROT_READ | PROT_WRITE,
465 MAP_SHARED, 0, &unused); 465 MAP_SHARED, 0, &unused);
466 up_write(&mm->mmap_sem); 466 up_write(&mm->mmap_sem);
467 if (IS_ERR((void *)ctx->mmap_base)) { 467 if (IS_ERR((void *)ctx->mmap_base)) {
468 ctx->mmap_size = 0; 468 ctx->mmap_size = 0;
469 aio_free_ring(ctx); 469 aio_free_ring(ctx);
470 return -ENOMEM; 470 return -ENOMEM;
471 } 471 }
472 472
473 pr_debug("mmap address: 0x%08lx\n", ctx->mmap_base); 473 pr_debug("mmap address: 0x%08lx\n", ctx->mmap_base);
474 474
475 ctx->user_id = ctx->mmap_base; 475 ctx->user_id = ctx->mmap_base;
476 ctx->nr_events = nr_events; /* trusted copy */ 476 ctx->nr_events = nr_events; /* trusted copy */
477 477
478 ring = kmap_atomic(ctx->ring_pages[0]); 478 ring = kmap_atomic(ctx->ring_pages[0]);
479 ring->nr = nr_events; /* user copy */ 479 ring->nr = nr_events; /* user copy */
480 ring->id = ~0U; 480 ring->id = ~0U;
481 ring->head = ring->tail = 0; 481 ring->head = ring->tail = 0;
482 ring->magic = AIO_RING_MAGIC; 482 ring->magic = AIO_RING_MAGIC;
483 ring->compat_features = AIO_RING_COMPAT_FEATURES; 483 ring->compat_features = AIO_RING_COMPAT_FEATURES;
484 ring->incompat_features = AIO_RING_INCOMPAT_FEATURES; 484 ring->incompat_features = AIO_RING_INCOMPAT_FEATURES;
485 ring->header_length = sizeof(struct aio_ring); 485 ring->header_length = sizeof(struct aio_ring);
486 kunmap_atomic(ring); 486 kunmap_atomic(ring);
487 flush_dcache_page(ctx->ring_pages[0]); 487 flush_dcache_page(ctx->ring_pages[0]);
488 488
489 return 0; 489 return 0;
490 } 490 }
491 491
492 #define AIO_EVENTS_PER_PAGE (PAGE_SIZE / sizeof(struct io_event)) 492 #define AIO_EVENTS_PER_PAGE (PAGE_SIZE / sizeof(struct io_event))
493 #define AIO_EVENTS_FIRST_PAGE ((PAGE_SIZE - sizeof(struct aio_ring)) / sizeof(struct io_event)) 493 #define AIO_EVENTS_FIRST_PAGE ((PAGE_SIZE - sizeof(struct aio_ring)) / sizeof(struct io_event))
494 #define AIO_EVENTS_OFFSET (AIO_EVENTS_PER_PAGE - AIO_EVENTS_FIRST_PAGE) 494 #define AIO_EVENTS_OFFSET (AIO_EVENTS_PER_PAGE - AIO_EVENTS_FIRST_PAGE)
495 495
496 void kiocb_set_cancel_fn(struct kiocb *req, kiocb_cancel_fn *cancel) 496 void kiocb_set_cancel_fn(struct kiocb *req, kiocb_cancel_fn *cancel)
497 { 497 {
498 struct kioctx *ctx = req->ki_ctx; 498 struct kioctx *ctx = req->ki_ctx;
499 unsigned long flags; 499 unsigned long flags;
500 500
501 spin_lock_irqsave(&ctx->ctx_lock, flags); 501 spin_lock_irqsave(&ctx->ctx_lock, flags);
502 502
503 if (!req->ki_list.next) 503 if (!req->ki_list.next)
504 list_add(&req->ki_list, &ctx->active_reqs); 504 list_add(&req->ki_list, &ctx->active_reqs);
505 505
506 req->ki_cancel = cancel; 506 req->ki_cancel = cancel;
507 507
508 spin_unlock_irqrestore(&ctx->ctx_lock, flags); 508 spin_unlock_irqrestore(&ctx->ctx_lock, flags);
509 } 509 }
510 EXPORT_SYMBOL(kiocb_set_cancel_fn); 510 EXPORT_SYMBOL(kiocb_set_cancel_fn);
511 511
512 static int kiocb_cancel(struct kiocb *kiocb) 512 static int kiocb_cancel(struct kiocb *kiocb)
513 { 513 {
514 kiocb_cancel_fn *old, *cancel; 514 kiocb_cancel_fn *old, *cancel;
515 515
516 /* 516 /*
517 * Don't want to set kiocb->ki_cancel = KIOCB_CANCELLED unless it 517 * Don't want to set kiocb->ki_cancel = KIOCB_CANCELLED unless it
518 * actually has a cancel function, hence the cmpxchg() 518 * actually has a cancel function, hence the cmpxchg()
519 */ 519 */
520 520
521 cancel = ACCESS_ONCE(kiocb->ki_cancel); 521 cancel = ACCESS_ONCE(kiocb->ki_cancel);
522 do { 522 do {
523 if (!cancel || cancel == KIOCB_CANCELLED) 523 if (!cancel || cancel == KIOCB_CANCELLED)
524 return -EINVAL; 524 return -EINVAL;
525 525
526 old = cancel; 526 old = cancel;
527 cancel = cmpxchg(&kiocb->ki_cancel, old, KIOCB_CANCELLED); 527 cancel = cmpxchg(&kiocb->ki_cancel, old, KIOCB_CANCELLED);
528 } while (cancel != old); 528 } while (cancel != old);
529 529
530 return cancel(kiocb); 530 return cancel(kiocb);
531 } 531 }
532 532
533 static void free_ioctx(struct work_struct *work) 533 static void free_ioctx(struct work_struct *work)
534 { 534 {
535 struct kioctx *ctx = container_of(work, struct kioctx, free_work); 535 struct kioctx *ctx = container_of(work, struct kioctx, free_work);
536 536
537 pr_debug("freeing %p\n", ctx); 537 pr_debug("freeing %p\n", ctx);
538 538
539 aio_free_ring(ctx); 539 aio_free_ring(ctx);
540 free_percpu(ctx->cpu); 540 free_percpu(ctx->cpu);
541 percpu_ref_exit(&ctx->reqs); 541 percpu_ref_exit(&ctx->reqs);
542 percpu_ref_exit(&ctx->users); 542 percpu_ref_exit(&ctx->users);
543 kmem_cache_free(kioctx_cachep, ctx); 543 kmem_cache_free(kioctx_cachep, ctx);
544 } 544 }
545 545
546 static void free_ioctx_reqs(struct percpu_ref *ref) 546 static void free_ioctx_reqs(struct percpu_ref *ref)
547 { 547 {
548 struct kioctx *ctx = container_of(ref, struct kioctx, reqs); 548 struct kioctx *ctx = container_of(ref, struct kioctx, reqs);
549 549
550 /* At this point we know that there are no any in-flight requests */ 550 /* At this point we know that there are no any in-flight requests */
551 if (ctx->requests_done) 551 if (ctx->requests_done)
552 complete(ctx->requests_done); 552 complete(ctx->requests_done);
553 553
554 INIT_WORK(&ctx->free_work, free_ioctx); 554 INIT_WORK(&ctx->free_work, free_ioctx);
555 schedule_work(&ctx->free_work); 555 schedule_work(&ctx->free_work);
556 } 556 }
557 557
558 /* 558 /*
559 * When this function runs, the kioctx has been removed from the "hash table" 559 * When this function runs, the kioctx has been removed from the "hash table"
560 * and ctx->users has dropped to 0, so we know no more kiocbs can be submitted - 560 * and ctx->users has dropped to 0, so we know no more kiocbs can be submitted -
561 * now it's safe to cancel any that need to be. 561 * now it's safe to cancel any that need to be.
562 */ 562 */
563 static void free_ioctx_users(struct percpu_ref *ref) 563 static void free_ioctx_users(struct percpu_ref *ref)
564 { 564 {
565 struct kioctx *ctx = container_of(ref, struct kioctx, users); 565 struct kioctx *ctx = container_of(ref, struct kioctx, users);
566 struct kiocb *req; 566 struct kiocb *req;
567 567
568 spin_lock_irq(&ctx->ctx_lock); 568 spin_lock_irq(&ctx->ctx_lock);
569 569
570 while (!list_empty(&ctx->active_reqs)) { 570 while (!list_empty(&ctx->active_reqs)) {
571 req = list_first_entry(&ctx->active_reqs, 571 req = list_first_entry(&ctx->active_reqs,
572 struct kiocb, ki_list); 572 struct kiocb, ki_list);
573 573
574 list_del_init(&req->ki_list); 574 list_del_init(&req->ki_list);
575 kiocb_cancel(req); 575 kiocb_cancel(req);
576 } 576 }
577 577
578 spin_unlock_irq(&ctx->ctx_lock); 578 spin_unlock_irq(&ctx->ctx_lock);
579 579
580 percpu_ref_kill(&ctx->reqs); 580 percpu_ref_kill(&ctx->reqs);
581 percpu_ref_put(&ctx->reqs); 581 percpu_ref_put(&ctx->reqs);
582 } 582 }
583 583
584 static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm) 584 static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
585 { 585 {
586 unsigned i, new_nr; 586 unsigned i, new_nr;
587 struct kioctx_table *table, *old; 587 struct kioctx_table *table, *old;
588 struct aio_ring *ring; 588 struct aio_ring *ring;
589 589
590 spin_lock(&mm->ioctx_lock); 590 spin_lock(&mm->ioctx_lock);
591 table = rcu_dereference_raw(mm->ioctx_table); 591 table = rcu_dereference_raw(mm->ioctx_table);
592 592
593 while (1) { 593 while (1) {
594 if (table) 594 if (table)
595 for (i = 0; i < table->nr; i++) 595 for (i = 0; i < table->nr; i++)
596 if (!table->table[i]) { 596 if (!table->table[i]) {
597 ctx->id = i; 597 ctx->id = i;
598 table->table[i] = ctx; 598 table->table[i] = ctx;
599 spin_unlock(&mm->ioctx_lock); 599 spin_unlock(&mm->ioctx_lock);
600 600
601 /* While kioctx setup is in progress, 601 /* While kioctx setup is in progress,
602 * we are protected from page migration 602 * we are protected from page migration
603 * changes ring_pages by ->ring_lock. 603 * changes ring_pages by ->ring_lock.
604 */ 604 */
605 ring = kmap_atomic(ctx->ring_pages[0]); 605 ring = kmap_atomic(ctx->ring_pages[0]);
606 ring->id = ctx->id; 606 ring->id = ctx->id;
607 kunmap_atomic(ring); 607 kunmap_atomic(ring);
608 return 0; 608 return 0;
609 } 609 }
610 610
611 new_nr = (table ? table->nr : 1) * 4; 611 new_nr = (table ? table->nr : 1) * 4;
612 spin_unlock(&mm->ioctx_lock); 612 spin_unlock(&mm->ioctx_lock);
613 613
614 table = kzalloc(sizeof(*table) + sizeof(struct kioctx *) * 614 table = kzalloc(sizeof(*table) + sizeof(struct kioctx *) *
615 new_nr, GFP_KERNEL); 615 new_nr, GFP_KERNEL);
616 if (!table) 616 if (!table)
617 return -ENOMEM; 617 return -ENOMEM;
618 618
619 table->nr = new_nr; 619 table->nr = new_nr;
620 620
621 spin_lock(&mm->ioctx_lock); 621 spin_lock(&mm->ioctx_lock);
622 old = rcu_dereference_raw(mm->ioctx_table); 622 old = rcu_dereference_raw(mm->ioctx_table);
623 623
624 if (!old) { 624 if (!old) {
625 rcu_assign_pointer(mm->ioctx_table, table); 625 rcu_assign_pointer(mm->ioctx_table, table);
626 } else if (table->nr > old->nr) { 626 } else if (table->nr > old->nr) {
627 memcpy(table->table, old->table, 627 memcpy(table->table, old->table,
628 old->nr * sizeof(struct kioctx *)); 628 old->nr * sizeof(struct kioctx *));
629 629
630 rcu_assign_pointer(mm->ioctx_table, table); 630 rcu_assign_pointer(mm->ioctx_table, table);
631 kfree_rcu(old, rcu); 631 kfree_rcu(old, rcu);
632 } else { 632 } else {
633 kfree(table); 633 kfree(table);
634 table = old; 634 table = old;
635 } 635 }
636 } 636 }
637 } 637 }
638 638
639 static void aio_nr_sub(unsigned nr) 639 static void aio_nr_sub(unsigned nr)
640 { 640 {
641 spin_lock(&aio_nr_lock); 641 spin_lock(&aio_nr_lock);
642 if (WARN_ON(aio_nr - nr > aio_nr)) 642 if (WARN_ON(aio_nr - nr > aio_nr))
643 aio_nr = 0; 643 aio_nr = 0;
644 else 644 else
645 aio_nr -= nr; 645 aio_nr -= nr;
646 spin_unlock(&aio_nr_lock); 646 spin_unlock(&aio_nr_lock);
647 } 647 }
648 648
649 /* ioctx_alloc 649 /* ioctx_alloc
650 * Allocates and initializes an ioctx. Returns an ERR_PTR if it failed. 650 * Allocates and initializes an ioctx. Returns an ERR_PTR if it failed.
651 */ 651 */
652 static struct kioctx *ioctx_alloc(unsigned nr_events) 652 static struct kioctx *ioctx_alloc(unsigned nr_events)
653 { 653 {
654 struct mm_struct *mm = current->mm; 654 struct mm_struct *mm = current->mm;
655 struct kioctx *ctx; 655 struct kioctx *ctx;
656 int err = -ENOMEM; 656 int err = -ENOMEM;
657 657
658 /* 658 /*
659 * We keep track of the number of available ringbuffer slots, to prevent 659 * We keep track of the number of available ringbuffer slots, to prevent
660 * overflow (reqs_available), and we also use percpu counters for this. 660 * overflow (reqs_available), and we also use percpu counters for this.
661 * 661 *
662 * So since up to half the slots might be on other cpu's percpu counters 662 * So since up to half the slots might be on other cpu's percpu counters
663 * and unavailable, double nr_events so userspace sees what they 663 * and unavailable, double nr_events so userspace sees what they
664 * expected: additionally, we move req_batch slots to/from percpu 664 * expected: additionally, we move req_batch slots to/from percpu
665 * counters at a time, so make sure that isn't 0: 665 * counters at a time, so make sure that isn't 0:
666 */ 666 */
667 nr_events = max(nr_events, num_possible_cpus() * 4); 667 nr_events = max(nr_events, num_possible_cpus() * 4);
668 nr_events *= 2; 668 nr_events *= 2;
669 669
670 /* Prevent overflows */ 670 /* Prevent overflows */
671 if ((nr_events > (0x10000000U / sizeof(struct io_event))) || 671 if ((nr_events > (0x10000000U / sizeof(struct io_event))) ||
672 (nr_events > (0x10000000U / sizeof(struct kiocb)))) { 672 (nr_events > (0x10000000U / sizeof(struct kiocb)))) {
673 pr_debug("ENOMEM: nr_events too high\n"); 673 pr_debug("ENOMEM: nr_events too high\n");
674 return ERR_PTR(-EINVAL); 674 return ERR_PTR(-EINVAL);
675 } 675 }
676 676
677 if (!nr_events || (unsigned long)nr_events > (aio_max_nr * 2UL)) 677 if (!nr_events || (unsigned long)nr_events > (aio_max_nr * 2UL))
678 return ERR_PTR(-EAGAIN); 678 return ERR_PTR(-EAGAIN);
679 679
680 ctx = kmem_cache_zalloc(kioctx_cachep, GFP_KERNEL); 680 ctx = kmem_cache_zalloc(kioctx_cachep, GFP_KERNEL);
681 if (!ctx) 681 if (!ctx)
682 return ERR_PTR(-ENOMEM); 682 return ERR_PTR(-ENOMEM);
683 683
684 ctx->max_reqs = nr_events; 684 ctx->max_reqs = nr_events;
685 685
686 spin_lock_init(&ctx->ctx_lock); 686 spin_lock_init(&ctx->ctx_lock);
687 spin_lock_init(&ctx->completion_lock); 687 spin_lock_init(&ctx->completion_lock);
688 mutex_init(&ctx->ring_lock); 688 mutex_init(&ctx->ring_lock);
689 /* Protect against page migration throughout kiotx setup by keeping 689 /* Protect against page migration throughout kiotx setup by keeping
690 * the ring_lock mutex held until setup is complete. */ 690 * the ring_lock mutex held until setup is complete. */
691 mutex_lock(&ctx->ring_lock); 691 mutex_lock(&ctx->ring_lock);
692 init_waitqueue_head(&ctx->wait); 692 init_waitqueue_head(&ctx->wait);
693 693
694 INIT_LIST_HEAD(&ctx->active_reqs); 694 INIT_LIST_HEAD(&ctx->active_reqs);
695 695
696 if (percpu_ref_init(&ctx->users, free_ioctx_users, 0, GFP_KERNEL)) 696 if (percpu_ref_init(&ctx->users, free_ioctx_users, 0, GFP_KERNEL))
697 goto err; 697 goto err;
698 698
699 if (percpu_ref_init(&ctx->reqs, free_ioctx_reqs, 0, GFP_KERNEL)) 699 if (percpu_ref_init(&ctx->reqs, free_ioctx_reqs, 0, GFP_KERNEL))
700 goto err; 700 goto err;
701 701
702 ctx->cpu = alloc_percpu(struct kioctx_cpu); 702 ctx->cpu = alloc_percpu(struct kioctx_cpu);
703 if (!ctx->cpu) 703 if (!ctx->cpu)
704 goto err; 704 goto err;
705 705
706 err = aio_setup_ring(ctx); 706 err = aio_setup_ring(ctx);
707 if (err < 0) 707 if (err < 0)
708 goto err; 708 goto err;
709 709
710 atomic_set(&ctx->reqs_available, ctx->nr_events - 1); 710 atomic_set(&ctx->reqs_available, ctx->nr_events - 1);
711 ctx->req_batch = (ctx->nr_events - 1) / (num_possible_cpus() * 4); 711 ctx->req_batch = (ctx->nr_events - 1) / (num_possible_cpus() * 4);
712 if (ctx->req_batch < 1) 712 if (ctx->req_batch < 1)
713 ctx->req_batch = 1; 713 ctx->req_batch = 1;
714 714
715 /* limit the number of system wide aios */ 715 /* limit the number of system wide aios */
716 spin_lock(&aio_nr_lock); 716 spin_lock(&aio_nr_lock);
717 if (aio_nr + nr_events > (aio_max_nr * 2UL) || 717 if (aio_nr + nr_events > (aio_max_nr * 2UL) ||
718 aio_nr + nr_events < aio_nr) { 718 aio_nr + nr_events < aio_nr) {
719 spin_unlock(&aio_nr_lock); 719 spin_unlock(&aio_nr_lock);
720 err = -EAGAIN; 720 err = -EAGAIN;
721 goto err_ctx; 721 goto err_ctx;
722 } 722 }
723 aio_nr += ctx->max_reqs; 723 aio_nr += ctx->max_reqs;
724 spin_unlock(&aio_nr_lock); 724 spin_unlock(&aio_nr_lock);
725 725
726 percpu_ref_get(&ctx->users); /* io_setup() will drop this ref */ 726 percpu_ref_get(&ctx->users); /* io_setup() will drop this ref */
727 percpu_ref_get(&ctx->reqs); /* free_ioctx_users() will drop this */ 727 percpu_ref_get(&ctx->reqs); /* free_ioctx_users() will drop this */
728 728
729 err = ioctx_add_table(ctx, mm); 729 err = ioctx_add_table(ctx, mm);
730 if (err) 730 if (err)
731 goto err_cleanup; 731 goto err_cleanup;
732 732
733 /* Release the ring_lock mutex now that all setup is complete. */ 733 /* Release the ring_lock mutex now that all setup is complete. */
734 mutex_unlock(&ctx->ring_lock); 734 mutex_unlock(&ctx->ring_lock);
735 735
736 pr_debug("allocated ioctx %p[%ld]: mm=%p mask=0x%x\n", 736 pr_debug("allocated ioctx %p[%ld]: mm=%p mask=0x%x\n",
737 ctx, ctx->user_id, mm, ctx->nr_events); 737 ctx, ctx->user_id, mm, ctx->nr_events);
738 return ctx; 738 return ctx;
739 739
740 err_cleanup: 740 err_cleanup:
741 aio_nr_sub(ctx->max_reqs); 741 aio_nr_sub(ctx->max_reqs);
742 err_ctx: 742 err_ctx:
743 aio_free_ring(ctx); 743 aio_free_ring(ctx);
744 err: 744 err:
745 mutex_unlock(&ctx->ring_lock); 745 mutex_unlock(&ctx->ring_lock);
746 free_percpu(ctx->cpu); 746 free_percpu(ctx->cpu);
747 percpu_ref_exit(&ctx->reqs); 747 percpu_ref_exit(&ctx->reqs);
748 percpu_ref_exit(&ctx->users); 748 percpu_ref_exit(&ctx->users);
749 kmem_cache_free(kioctx_cachep, ctx); 749 kmem_cache_free(kioctx_cachep, ctx);
750 pr_debug("error allocating ioctx %d\n", err); 750 pr_debug("error allocating ioctx %d\n", err);
751 return ERR_PTR(err); 751 return ERR_PTR(err);
752 } 752 }
753 753
754 /* kill_ioctx 754 /* kill_ioctx
755 * Cancels all outstanding aio requests on an aio context. Used 755 * Cancels all outstanding aio requests on an aio context. Used
756 * when the processes owning a context have all exited to encourage 756 * when the processes owning a context have all exited to encourage
757 * the rapid destruction of the kioctx. 757 * the rapid destruction of the kioctx.
758 */ 758 */
759 static int kill_ioctx(struct mm_struct *mm, struct kioctx *ctx, 759 static int kill_ioctx(struct mm_struct *mm, struct kioctx *ctx,
760 struct completion *requests_done) 760 struct completion *requests_done)
761 { 761 {
762 struct kioctx_table *table; 762 struct kioctx_table *table;
763 763
764 if (atomic_xchg(&ctx->dead, 1)) 764 if (atomic_xchg(&ctx->dead, 1))
765 return -EINVAL; 765 return -EINVAL;
766 766
767 767
768 spin_lock(&mm->ioctx_lock); 768 spin_lock(&mm->ioctx_lock);
769 table = rcu_dereference_raw(mm->ioctx_table); 769 table = rcu_dereference_raw(mm->ioctx_table);
770 WARN_ON(ctx != table->table[ctx->id]); 770 WARN_ON(ctx != table->table[ctx->id]);
771 table->table[ctx->id] = NULL; 771 table->table[ctx->id] = NULL;
772 spin_unlock(&mm->ioctx_lock); 772 spin_unlock(&mm->ioctx_lock);
773 773
774 /* percpu_ref_kill() will do the necessary call_rcu() */ 774 /* percpu_ref_kill() will do the necessary call_rcu() */
775 wake_up_all(&ctx->wait); 775 wake_up_all(&ctx->wait);
776 776
777 /* 777 /*
778 * It'd be more correct to do this in free_ioctx(), after all 778 * It'd be more correct to do this in free_ioctx(), after all
779 * the outstanding kiocbs have finished - but by then io_destroy 779 * the outstanding kiocbs have finished - but by then io_destroy
780 * has already returned, so io_setup() could potentially return 780 * has already returned, so io_setup() could potentially return
781 * -EAGAIN with no ioctxs actually in use (as far as userspace 781 * -EAGAIN with no ioctxs actually in use (as far as userspace
782 * could tell). 782 * could tell).
783 */ 783 */
784 aio_nr_sub(ctx->max_reqs); 784 aio_nr_sub(ctx->max_reqs);
785 785
786 if (ctx->mmap_size) 786 if (ctx->mmap_size)
787 vm_munmap(ctx->mmap_base, ctx->mmap_size); 787 vm_munmap(ctx->mmap_base, ctx->mmap_size);
788 788
789 ctx->requests_done = requests_done; 789 ctx->requests_done = requests_done;
790 percpu_ref_kill(&ctx->users); 790 percpu_ref_kill(&ctx->users);
791 return 0; 791 return 0;
792 } 792 }
793 793
794 /* wait_on_sync_kiocb: 794 /* wait_on_sync_kiocb:
795 * Waits on the given sync kiocb to complete. 795 * Waits on the given sync kiocb to complete.
796 */ 796 */
797 ssize_t wait_on_sync_kiocb(struct kiocb *req) 797 ssize_t wait_on_sync_kiocb(struct kiocb *req)
798 { 798 {
799 while (!req->ki_ctx) { 799 while (!req->ki_ctx) {
800 set_current_state(TASK_UNINTERRUPTIBLE); 800 set_current_state(TASK_UNINTERRUPTIBLE);
801 if (req->ki_ctx) 801 if (req->ki_ctx)
802 break; 802 break;
803 io_schedule(); 803 io_schedule();
804 } 804 }
805 __set_current_state(TASK_RUNNING); 805 __set_current_state(TASK_RUNNING);
806 return req->ki_user_data; 806 return req->ki_user_data;
807 } 807 }
808 EXPORT_SYMBOL(wait_on_sync_kiocb); 808 EXPORT_SYMBOL(wait_on_sync_kiocb);
809 809
810 /* 810 /*
811 * exit_aio: called when the last user of mm goes away. At this point, there is 811 * exit_aio: called when the last user of mm goes away. At this point, there is
812 * no way for any new requests to be submited or any of the io_* syscalls to be 812 * no way for any new requests to be submited or any of the io_* syscalls to be
813 * called on the context. 813 * called on the context.
814 * 814 *
815 * There may be outstanding kiocbs, but free_ioctx() will explicitly wait on 815 * There may be outstanding kiocbs, but free_ioctx() will explicitly wait on
816 * them. 816 * them.
817 */ 817 */
818 void exit_aio(struct mm_struct *mm) 818 void exit_aio(struct mm_struct *mm)
819 { 819 {
820 struct kioctx_table *table = rcu_dereference_raw(mm->ioctx_table); 820 struct kioctx_table *table = rcu_dereference_raw(mm->ioctx_table);
821 int i; 821 int i;
822 822
823 if (!table) 823 if (!table)
824 return; 824 return;
825 825
826 for (i = 0; i < table->nr; ++i) { 826 for (i = 0; i < table->nr; ++i) {
827 struct kioctx *ctx = table->table[i]; 827 struct kioctx *ctx = table->table[i];
828 struct completion requests_done = 828 struct completion requests_done =
829 COMPLETION_INITIALIZER_ONSTACK(requests_done); 829 COMPLETION_INITIALIZER_ONSTACK(requests_done);
830 830
831 if (!ctx) 831 if (!ctx)
832 continue; 832 continue;
833 /* 833 /*
834 * We don't need to bother with munmap() here - exit_mmap(mm) 834 * We don't need to bother with munmap() here - exit_mmap(mm)
835 * is coming and it'll unmap everything. And we simply can't, 835 * is coming and it'll unmap everything. And we simply can't,
836 * this is not necessarily our ->mm. 836 * this is not necessarily our ->mm.
837 * Since kill_ioctx() uses non-zero ->mmap_size as indicator 837 * Since kill_ioctx() uses non-zero ->mmap_size as indicator
838 * that it needs to unmap the area, just set it to 0. 838 * that it needs to unmap the area, just set it to 0.
839 */ 839 */
840 ctx->mmap_size = 0; 840 ctx->mmap_size = 0;
841 kill_ioctx(mm, ctx, &requests_done); 841 kill_ioctx(mm, ctx, &requests_done);
842 842
843 /* Wait until all IO for the context are done. */ 843 /* Wait until all IO for the context are done. */
844 wait_for_completion(&requests_done); 844 wait_for_completion(&requests_done);
845 } 845 }
846 846
847 RCU_INIT_POINTER(mm->ioctx_table, NULL); 847 RCU_INIT_POINTER(mm->ioctx_table, NULL);
848 kfree(table); 848 kfree(table);
849 } 849 }
850 850
851 static void put_reqs_available(struct kioctx *ctx, unsigned nr) 851 static void put_reqs_available(struct kioctx *ctx, unsigned nr)
852 { 852 {
853 struct kioctx_cpu *kcpu; 853 struct kioctx_cpu *kcpu;
854 unsigned long flags; 854 unsigned long flags;
855 855
856 local_irq_save(flags); 856 local_irq_save(flags);
857 kcpu = this_cpu_ptr(ctx->cpu); 857 kcpu = this_cpu_ptr(ctx->cpu);
858 kcpu->reqs_available += nr; 858 kcpu->reqs_available += nr;
859 859
860 while (kcpu->reqs_available >= ctx->req_batch * 2) { 860 while (kcpu->reqs_available >= ctx->req_batch * 2) {
861 kcpu->reqs_available -= ctx->req_batch; 861 kcpu->reqs_available -= ctx->req_batch;
862 atomic_add(ctx->req_batch, &ctx->reqs_available); 862 atomic_add(ctx->req_batch, &ctx->reqs_available);
863 } 863 }
864 864
865 local_irq_restore(flags); 865 local_irq_restore(flags);
866 } 866 }
867 867
868 static bool get_reqs_available(struct kioctx *ctx) 868 static bool get_reqs_available(struct kioctx *ctx)
869 { 869 {
870 struct kioctx_cpu *kcpu; 870 struct kioctx_cpu *kcpu;
871 bool ret = false; 871 bool ret = false;
872 unsigned long flags; 872 unsigned long flags;
873 873
874 local_irq_save(flags); 874 local_irq_save(flags);
875 kcpu = this_cpu_ptr(ctx->cpu); 875 kcpu = this_cpu_ptr(ctx->cpu);
876 if (!kcpu->reqs_available) { 876 if (!kcpu->reqs_available) {
877 int old, avail = atomic_read(&ctx->reqs_available); 877 int old, avail = atomic_read(&ctx->reqs_available);
878 878
879 do { 879 do {
880 if (avail < ctx->req_batch) 880 if (avail < ctx->req_batch)
881 goto out; 881 goto out;
882 882
883 old = avail; 883 old = avail;
884 avail = atomic_cmpxchg(&ctx->reqs_available, 884 avail = atomic_cmpxchg(&ctx->reqs_available,
885 avail, avail - ctx->req_batch); 885 avail, avail - ctx->req_batch);
886 } while (avail != old); 886 } while (avail != old);
887 887
888 kcpu->reqs_available += ctx->req_batch; 888 kcpu->reqs_available += ctx->req_batch;
889 } 889 }
890 890
891 ret = true; 891 ret = true;
892 kcpu->reqs_available--; 892 kcpu->reqs_available--;
893 out: 893 out:
894 local_irq_restore(flags); 894 local_irq_restore(flags);
895 return ret; 895 return ret;
896 } 896 }
897 897
898 /* refill_reqs_available 898 /* refill_reqs_available
899 * Updates the reqs_available reference counts used for tracking the 899 * Updates the reqs_available reference counts used for tracking the
900 * number of free slots in the completion ring. This can be called 900 * number of free slots in the completion ring. This can be called
901 * from aio_complete() (to optimistically update reqs_available) or 901 * from aio_complete() (to optimistically update reqs_available) or
902 * from aio_get_req() (the we're out of events case). It must be 902 * from aio_get_req() (the we're out of events case). It must be
903 * called holding ctx->completion_lock. 903 * called holding ctx->completion_lock.
904 */ 904 */
905 static void refill_reqs_available(struct kioctx *ctx, unsigned head, 905 static void refill_reqs_available(struct kioctx *ctx, unsigned head,
906 unsigned tail) 906 unsigned tail)
907 { 907 {
908 unsigned events_in_ring, completed; 908 unsigned events_in_ring, completed;
909 909
910 /* Clamp head since userland can write to it. */ 910 /* Clamp head since userland can write to it. */
911 head %= ctx->nr_events; 911 head %= ctx->nr_events;
912 if (head <= tail) 912 if (head <= tail)
913 events_in_ring = tail - head; 913 events_in_ring = tail - head;
914 else 914 else
915 events_in_ring = ctx->nr_events - (head - tail); 915 events_in_ring = ctx->nr_events - (head - tail);
916 916
917 completed = ctx->completed_events; 917 completed = ctx->completed_events;
918 if (events_in_ring < completed) 918 if (events_in_ring < completed)
919 completed -= events_in_ring; 919 completed -= events_in_ring;
920 else 920 else
921 completed = 0; 921 completed = 0;
922 922
923 if (!completed) 923 if (!completed)
924 return; 924 return;
925 925
926 ctx->completed_events -= completed; 926 ctx->completed_events -= completed;
927 put_reqs_available(ctx, completed); 927 put_reqs_available(ctx, completed);
928 } 928 }
929 929
930 /* user_refill_reqs_available 930 /* user_refill_reqs_available
931 * Called to refill reqs_available when aio_get_req() encounters an 931 * Called to refill reqs_available when aio_get_req() encounters an
932 * out of space in the completion ring. 932 * out of space in the completion ring.
933 */ 933 */
934 static void user_refill_reqs_available(struct kioctx *ctx) 934 static void user_refill_reqs_available(struct kioctx *ctx)
935 { 935 {
936 spin_lock_irq(&ctx->completion_lock); 936 spin_lock_irq(&ctx->completion_lock);
937 if (ctx->completed_events) { 937 if (ctx->completed_events) {
938 struct aio_ring *ring; 938 struct aio_ring *ring;
939 unsigned head; 939 unsigned head;
940 940
941 /* Access of ring->head may race with aio_read_events_ring() 941 /* Access of ring->head may race with aio_read_events_ring()
942 * here, but that's okay since whether we read the old version 942 * here, but that's okay since whether we read the old version
943 * or the new version, and either will be valid. The important 943 * or the new version, and either will be valid. The important
944 * part is that head cannot pass tail since we prevent 944 * part is that head cannot pass tail since we prevent
945 * aio_complete() from updating tail by holding 945 * aio_complete() from updating tail by holding
946 * ctx->completion_lock. Even if head is invalid, the check 946 * ctx->completion_lock. Even if head is invalid, the check
947 * against ctx->completed_events below will make sure we do the 947 * against ctx->completed_events below will make sure we do the
948 * safe/right thing. 948 * safe/right thing.
949 */ 949 */
950 ring = kmap_atomic(ctx->ring_pages[0]); 950 ring = kmap_atomic(ctx->ring_pages[0]);
951 head = ring->head; 951 head = ring->head;
952 kunmap_atomic(ring); 952 kunmap_atomic(ring);
953 953
954 refill_reqs_available(ctx, head, ctx->tail); 954 refill_reqs_available(ctx, head, ctx->tail);
955 } 955 }
956 956
957 spin_unlock_irq(&ctx->completion_lock); 957 spin_unlock_irq(&ctx->completion_lock);
958 } 958 }
959 959
960 /* aio_get_req 960 /* aio_get_req
961 * Allocate a slot for an aio request. 961 * Allocate a slot for an aio request.
962 * Returns NULL if no requests are free. 962 * Returns NULL if no requests are free.
963 */ 963 */
964 static inline struct kiocb *aio_get_req(struct kioctx *ctx) 964 static inline struct kiocb *aio_get_req(struct kioctx *ctx)
965 { 965 {
966 struct kiocb *req; 966 struct kiocb *req;
967 967
968 if (!get_reqs_available(ctx)) { 968 if (!get_reqs_available(ctx)) {
969 user_refill_reqs_available(ctx); 969 user_refill_reqs_available(ctx);
970 if (!get_reqs_available(ctx)) 970 if (!get_reqs_available(ctx))
971 return NULL; 971 return NULL;
972 } 972 }
973 973
974 req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL|__GFP_ZERO); 974 req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL|__GFP_ZERO);
975 if (unlikely(!req)) 975 if (unlikely(!req))
976 goto out_put; 976 goto out_put;
977 977
978 percpu_ref_get(&ctx->reqs); 978 percpu_ref_get(&ctx->reqs);
979 979
980 req->ki_ctx = ctx; 980 req->ki_ctx = ctx;
981 return req; 981 return req;
982 out_put: 982 out_put:
983 put_reqs_available(ctx, 1); 983 put_reqs_available(ctx, 1);
984 return NULL; 984 return NULL;
985 } 985 }
986 986
987 static void kiocb_free(struct kiocb *req) 987 static void kiocb_free(struct kiocb *req)
988 { 988 {
989 if (req->ki_filp) 989 if (req->ki_filp)
990 fput(req->ki_filp); 990 fput(req->ki_filp);
991 if (req->ki_eventfd != NULL) 991 if (req->ki_eventfd != NULL)
992 eventfd_ctx_put(req->ki_eventfd); 992 eventfd_ctx_put(req->ki_eventfd);
993 kmem_cache_free(kiocb_cachep, req); 993 kmem_cache_free(kiocb_cachep, req);
994 } 994 }
995 995
996 static struct kioctx *lookup_ioctx(unsigned long ctx_id) 996 static struct kioctx *lookup_ioctx(unsigned long ctx_id)
997 { 997 {
998 struct aio_ring __user *ring = (void __user *)ctx_id; 998 struct aio_ring __user *ring = (void __user *)ctx_id;
999 struct mm_struct *mm = current->mm; 999 struct mm_struct *mm = current->mm;
1000 struct kioctx *ctx, *ret = NULL; 1000 struct kioctx *ctx, *ret = NULL;
1001 struct kioctx_table *table; 1001 struct kioctx_table *table;
1002 unsigned id; 1002 unsigned id;
1003 1003
1004 if (get_user(id, &ring->id)) 1004 if (get_user(id, &ring->id))
1005 return NULL; 1005 return NULL;
1006 1006
1007 rcu_read_lock(); 1007 rcu_read_lock();
1008 table = rcu_dereference(mm->ioctx_table); 1008 table = rcu_dereference(mm->ioctx_table);
1009 1009
1010 if (!table || id >= table->nr) 1010 if (!table || id >= table->nr)
1011 goto out; 1011 goto out;
1012 1012
1013 ctx = table->table[id]; 1013 ctx = table->table[id];
1014 if (ctx && ctx->user_id == ctx_id) { 1014 if (ctx && ctx->user_id == ctx_id) {
1015 percpu_ref_get(&ctx->users); 1015 percpu_ref_get(&ctx->users);
1016 ret = ctx; 1016 ret = ctx;
1017 } 1017 }
1018 out: 1018 out:
1019 rcu_read_unlock(); 1019 rcu_read_unlock();
1020 return ret; 1020 return ret;
1021 } 1021 }
1022 1022
1023 /* aio_complete 1023 /* aio_complete
1024 * Called when the io request on the given iocb is complete. 1024 * Called when the io request on the given iocb is complete.
1025 */ 1025 */
1026 void aio_complete(struct kiocb *iocb, long res, long res2) 1026 void aio_complete(struct kiocb *iocb, long res, long res2)
1027 { 1027 {
1028 struct kioctx *ctx = iocb->ki_ctx; 1028 struct kioctx *ctx = iocb->ki_ctx;
1029 struct aio_ring *ring; 1029 struct aio_ring *ring;
1030 struct io_event *ev_page, *event; 1030 struct io_event *ev_page, *event;
1031 unsigned tail, pos, head; 1031 unsigned tail, pos, head;
1032 unsigned long flags; 1032 unsigned long flags;
1033 1033
1034 /* 1034 /*
1035 * Special case handling for sync iocbs: 1035 * Special case handling for sync iocbs:
1036 * - events go directly into the iocb for fast handling 1036 * - events go directly into the iocb for fast handling
1037 * - the sync task with the iocb in its stack holds the single iocb 1037 * - the sync task with the iocb in its stack holds the single iocb
1038 * ref, no other paths have a way to get another ref 1038 * ref, no other paths have a way to get another ref
1039 * - the sync task helpfully left a reference to itself in the iocb 1039 * - the sync task helpfully left a reference to itself in the iocb
1040 */ 1040 */
1041 if (is_sync_kiocb(iocb)) { 1041 if (is_sync_kiocb(iocb)) {
1042 iocb->ki_user_data = res; 1042 iocb->ki_user_data = res;
1043 smp_wmb(); 1043 smp_wmb();
1044 iocb->ki_ctx = ERR_PTR(-EXDEV); 1044 iocb->ki_ctx = ERR_PTR(-EXDEV);
1045 wake_up_process(iocb->ki_obj.tsk); 1045 wake_up_process(iocb->ki_obj.tsk);
1046 return; 1046 return;
1047 } 1047 }
1048 1048
1049 if (iocb->ki_list.next) { 1049 if (iocb->ki_list.next) {
1050 unsigned long flags; 1050 unsigned long flags;
1051 1051
1052 spin_lock_irqsave(&ctx->ctx_lock, flags); 1052 spin_lock_irqsave(&ctx->ctx_lock, flags);
1053 list_del(&iocb->ki_list); 1053 list_del(&iocb->ki_list);
1054 spin_unlock_irqrestore(&ctx->ctx_lock, flags); 1054 spin_unlock_irqrestore(&ctx->ctx_lock, flags);
1055 } 1055 }
1056 1056
1057 /* 1057 /*
1058 * Add a completion event to the ring buffer. Must be done holding 1058 * Add a completion event to the ring buffer. Must be done holding
1059 * ctx->completion_lock to prevent other code from messing with the tail 1059 * ctx->completion_lock to prevent other code from messing with the tail
1060 * pointer since we might be called from irq context. 1060 * pointer since we might be called from irq context.
1061 */ 1061 */
1062 spin_lock_irqsave(&ctx->completion_lock, flags); 1062 spin_lock_irqsave(&ctx->completion_lock, flags);
1063 1063
1064 tail = ctx->tail; 1064 tail = ctx->tail;
1065 pos = tail + AIO_EVENTS_OFFSET; 1065 pos = tail + AIO_EVENTS_OFFSET;
1066 1066
1067 if (++tail >= ctx->nr_events) 1067 if (++tail >= ctx->nr_events)
1068 tail = 0; 1068 tail = 0;
1069 1069
1070 ev_page = kmap_atomic(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]); 1070 ev_page = kmap_atomic(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]);
1071 event = ev_page + pos % AIO_EVENTS_PER_PAGE; 1071 event = ev_page + pos % AIO_EVENTS_PER_PAGE;
1072 1072
1073 event->obj = (u64)(unsigned long)iocb->ki_obj.user; 1073 event->obj = (u64)(unsigned long)iocb->ki_obj.user;
1074 event->data = iocb->ki_user_data; 1074 event->data = iocb->ki_user_data;
1075 event->res = res; 1075 event->res = res;
1076 event->res2 = res2; 1076 event->res2 = res2;
1077 1077
1078 kunmap_atomic(ev_page); 1078 kunmap_atomic(ev_page);
1079 flush_dcache_page(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]); 1079 flush_dcache_page(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]);
1080 1080
1081 pr_debug("%p[%u]: %p: %p %Lx %lx %lx\n", 1081 pr_debug("%p[%u]: %p: %p %Lx %lx %lx\n",
1082 ctx, tail, iocb, iocb->ki_obj.user, iocb->ki_user_data, 1082 ctx, tail, iocb, iocb->ki_obj.user, iocb->ki_user_data,
1083 res, res2); 1083 res, res2);
1084 1084
1085 /* after flagging the request as done, we 1085 /* after flagging the request as done, we
1086 * must never even look at it again 1086 * must never even look at it again
1087 */ 1087 */
1088 smp_wmb(); /* make event visible before updating tail */ 1088 smp_wmb(); /* make event visible before updating tail */
1089 1089
1090 ctx->tail = tail; 1090 ctx->tail = tail;
1091 1091
1092 ring = kmap_atomic(ctx->ring_pages[0]); 1092 ring = kmap_atomic(ctx->ring_pages[0]);
1093 head = ring->head; 1093 head = ring->head;
1094 ring->tail = tail; 1094 ring->tail = tail;
1095 kunmap_atomic(ring); 1095 kunmap_atomic(ring);
1096 flush_dcache_page(ctx->ring_pages[0]); 1096 flush_dcache_page(ctx->ring_pages[0]);
1097 1097
1098 ctx->completed_events++; 1098 ctx->completed_events++;
1099 if (ctx->completed_events > 1) 1099 if (ctx->completed_events > 1)
1100 refill_reqs_available(ctx, head, tail); 1100 refill_reqs_available(ctx, head, tail);
1101 spin_unlock_irqrestore(&ctx->completion_lock, flags); 1101 spin_unlock_irqrestore(&ctx->completion_lock, flags);
1102 1102
1103 pr_debug("added to ring %p at [%u]\n", iocb, tail); 1103 pr_debug("added to ring %p at [%u]\n", iocb, tail);
1104 1104
1105 /* 1105 /*
1106 * Check if the user asked us to deliver the result through an 1106 * Check if the user asked us to deliver the result through an
1107 * eventfd. The eventfd_signal() function is safe to be called 1107 * eventfd. The eventfd_signal() function is safe to be called
1108 * from IRQ context. 1108 * from IRQ context.
1109 */ 1109 */
1110 if (iocb->ki_eventfd != NULL) 1110 if (iocb->ki_eventfd != NULL)
1111 eventfd_signal(iocb->ki_eventfd, 1); 1111 eventfd_signal(iocb->ki_eventfd, 1);
1112 1112
1113 /* everything turned out well, dispose of the aiocb. */ 1113 /* everything turned out well, dispose of the aiocb. */
1114 kiocb_free(iocb); 1114 kiocb_free(iocb);
1115 1115
1116 /* 1116 /*
1117 * We have to order our ring_info tail store above and test 1117 * We have to order our ring_info tail store above and test
1118 * of the wait list below outside the wait lock. This is 1118 * of the wait list below outside the wait lock. This is
1119 * like in wake_up_bit() where clearing a bit has to be 1119 * like in wake_up_bit() where clearing a bit has to be
1120 * ordered with the unlocked test. 1120 * ordered with the unlocked test.
1121 */ 1121 */
1122 smp_mb(); 1122 smp_mb();
1123 1123
1124 if (waitqueue_active(&ctx->wait)) 1124 if (waitqueue_active(&ctx->wait))
1125 wake_up(&ctx->wait); 1125 wake_up(&ctx->wait);
1126 1126
1127 percpu_ref_put(&ctx->reqs); 1127 percpu_ref_put(&ctx->reqs);
1128 } 1128 }
1129 EXPORT_SYMBOL(aio_complete); 1129 EXPORT_SYMBOL(aio_complete);
1130 1130
1131 /* aio_read_events_ring 1131 /* aio_read_events_ring
1132 * Pull an event off of the ioctx's event ring. Returns the number of 1132 * Pull an event off of the ioctx's event ring. Returns the number of
1133 * events fetched 1133 * events fetched
1134 */ 1134 */
1135 static long aio_read_events_ring(struct kioctx *ctx, 1135 static long aio_read_events_ring(struct kioctx *ctx,
1136 struct io_event __user *event, long nr) 1136 struct io_event __user *event, long nr)
1137 { 1137 {
1138 struct aio_ring *ring; 1138 struct aio_ring *ring;
1139 unsigned head, tail, pos; 1139 unsigned head, tail, pos;
1140 long ret = 0; 1140 long ret = 0;
1141 int copy_ret; 1141 int copy_ret;
1142 1142
1143 /*
1144 * The mutex can block and wake us up and that will cause
1145 * wait_event_interruptible_hrtimeout() to schedule without sleeping
1146 * and repeat. This should be rare enough that it doesn't cause
1147 * peformance issues. See the comment in read_events() for more detail.
1148 */
1149 sched_annotate_sleep();
1143 mutex_lock(&ctx->ring_lock); 1150 mutex_lock(&ctx->ring_lock);
1144 1151
1145 /* Access to ->ring_pages here is protected by ctx->ring_lock. */ 1152 /* Access to ->ring_pages here is protected by ctx->ring_lock. */
1146 ring = kmap_atomic(ctx->ring_pages[0]); 1153 ring = kmap_atomic(ctx->ring_pages[0]);
1147 head = ring->head; 1154 head = ring->head;
1148 tail = ring->tail; 1155 tail = ring->tail;
1149 kunmap_atomic(ring); 1156 kunmap_atomic(ring);
1150 1157
1151 /* 1158 /*
1152 * Ensure that once we've read the current tail pointer, that 1159 * Ensure that once we've read the current tail pointer, that
1153 * we also see the events that were stored up to the tail. 1160 * we also see the events that were stored up to the tail.
1154 */ 1161 */
1155 smp_rmb(); 1162 smp_rmb();
1156 1163
1157 pr_debug("h%u t%u m%u\n", head, tail, ctx->nr_events); 1164 pr_debug("h%u t%u m%u\n", head, tail, ctx->nr_events);
1158 1165
1159 if (head == tail) 1166 if (head == tail)
1160 goto out; 1167 goto out;
1161 1168
1162 head %= ctx->nr_events; 1169 head %= ctx->nr_events;
1163 tail %= ctx->nr_events; 1170 tail %= ctx->nr_events;
1164 1171
1165 while (ret < nr) { 1172 while (ret < nr) {
1166 long avail; 1173 long avail;
1167 struct io_event *ev; 1174 struct io_event *ev;
1168 struct page *page; 1175 struct page *page;
1169 1176
1170 avail = (head <= tail ? tail : ctx->nr_events) - head; 1177 avail = (head <= tail ? tail : ctx->nr_events) - head;
1171 if (head == tail) 1178 if (head == tail)
1172 break; 1179 break;
1173 1180
1174 avail = min(avail, nr - ret); 1181 avail = min(avail, nr - ret);
1175 avail = min_t(long, avail, AIO_EVENTS_PER_PAGE - 1182 avail = min_t(long, avail, AIO_EVENTS_PER_PAGE -
1176 ((head + AIO_EVENTS_OFFSET) % AIO_EVENTS_PER_PAGE)); 1183 ((head + AIO_EVENTS_OFFSET) % AIO_EVENTS_PER_PAGE));
1177 1184
1178 pos = head + AIO_EVENTS_OFFSET; 1185 pos = head + AIO_EVENTS_OFFSET;
1179 page = ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]; 1186 page = ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE];
1180 pos %= AIO_EVENTS_PER_PAGE; 1187 pos %= AIO_EVENTS_PER_PAGE;
1181 1188
1182 ev = kmap(page); 1189 ev = kmap(page);
1183 copy_ret = copy_to_user(event + ret, ev + pos, 1190 copy_ret = copy_to_user(event + ret, ev + pos,
1184 sizeof(*ev) * avail); 1191 sizeof(*ev) * avail);
1185 kunmap(page); 1192 kunmap(page);
1186 1193
1187 if (unlikely(copy_ret)) { 1194 if (unlikely(copy_ret)) {
1188 ret = -EFAULT; 1195 ret = -EFAULT;
1189 goto out; 1196 goto out;
1190 } 1197 }
1191 1198
1192 ret += avail; 1199 ret += avail;
1193 head += avail; 1200 head += avail;
1194 head %= ctx->nr_events; 1201 head %= ctx->nr_events;
1195 } 1202 }
1196 1203
1197 ring = kmap_atomic(ctx->ring_pages[0]); 1204 ring = kmap_atomic(ctx->ring_pages[0]);
1198 ring->head = head; 1205 ring->head = head;
1199 kunmap_atomic(ring); 1206 kunmap_atomic(ring);
1200 flush_dcache_page(ctx->ring_pages[0]); 1207 flush_dcache_page(ctx->ring_pages[0]);
1201 1208
1202 pr_debug("%li h%u t%u\n", ret, head, tail); 1209 pr_debug("%li h%u t%u\n", ret, head, tail);
1203 out: 1210 out:
1204 mutex_unlock(&ctx->ring_lock); 1211 mutex_unlock(&ctx->ring_lock);
1205 1212
1206 return ret; 1213 return ret;
1207 } 1214 }
1208 1215
1209 static bool aio_read_events(struct kioctx *ctx, long min_nr, long nr, 1216 static bool aio_read_events(struct kioctx *ctx, long min_nr, long nr,
1210 struct io_event __user *event, long *i) 1217 struct io_event __user *event, long *i)
1211 { 1218 {
1212 long ret = aio_read_events_ring(ctx, event + *i, nr - *i); 1219 long ret = aio_read_events_ring(ctx, event + *i, nr - *i);
1213 1220
1214 if (ret > 0) 1221 if (ret > 0)
1215 *i += ret; 1222 *i += ret;
1216 1223
1217 if (unlikely(atomic_read(&ctx->dead))) 1224 if (unlikely(atomic_read(&ctx->dead)))
1218 ret = -EINVAL; 1225 ret = -EINVAL;
1219 1226
1220 if (!*i) 1227 if (!*i)
1221 *i = ret; 1228 *i = ret;
1222 1229
1223 return ret < 0 || *i >= min_nr; 1230 return ret < 0 || *i >= min_nr;
1224 } 1231 }
1225 1232
1226 static long read_events(struct kioctx *ctx, long min_nr, long nr, 1233 static long read_events(struct kioctx *ctx, long min_nr, long nr,
1227 struct io_event __user *event, 1234 struct io_event __user *event,
1228 struct timespec __user *timeout) 1235 struct timespec __user *timeout)
1229 { 1236 {
1230 ktime_t until = { .tv64 = KTIME_MAX }; 1237 ktime_t until = { .tv64 = KTIME_MAX };
1231 long ret = 0; 1238 long ret = 0;
1232 1239
1233 if (timeout) { 1240 if (timeout) {
1234 struct timespec ts; 1241 struct timespec ts;
1235 1242
1236 if (unlikely(copy_from_user(&ts, timeout, sizeof(ts)))) 1243 if (unlikely(copy_from_user(&ts, timeout, sizeof(ts))))
1237 return -EFAULT; 1244 return -EFAULT;
1238 1245
1239 until = timespec_to_ktime(ts); 1246 until = timespec_to_ktime(ts);
1240 } 1247 }
1241 1248
1242 /* 1249 /*
1243 * Note that aio_read_events() is being called as the conditional - i.e. 1250 * Note that aio_read_events() is being called as the conditional - i.e.
1244 * we're calling it after prepare_to_wait() has set task state to 1251 * we're calling it after prepare_to_wait() has set task state to
1245 * TASK_INTERRUPTIBLE. 1252 * TASK_INTERRUPTIBLE.
1246 * 1253 *
1247 * But aio_read_events() can block, and if it blocks it's going to flip 1254 * But aio_read_events() can block, and if it blocks it's going to flip
1248 * the task state back to TASK_RUNNING. 1255 * the task state back to TASK_RUNNING.
1249 * 1256 *
1250 * This should be ok, provided it doesn't flip the state back to 1257 * This should be ok, provided it doesn't flip the state back to
1251 * TASK_RUNNING and return 0 too much - that causes us to spin. That 1258 * TASK_RUNNING and return 0 too much - that causes us to spin. That
1252 * will only happen if the mutex_lock() call blocks, and we then find 1259 * will only happen if the mutex_lock() call blocks, and we then find
1253 * the ringbuffer empty. So in practice we should be ok, but it's 1260 * the ringbuffer empty. So in practice we should be ok, but it's
1254 * something to be aware of when touching this code. 1261 * something to be aware of when touching this code.
1255 */ 1262 */
1256 if (until.tv64 == 0) 1263 if (until.tv64 == 0)
1257 aio_read_events(ctx, min_nr, nr, event, &ret); 1264 aio_read_events(ctx, min_nr, nr, event, &ret);
1258 else 1265 else
1259 wait_event_interruptible_hrtimeout(ctx->wait, 1266 wait_event_interruptible_hrtimeout(ctx->wait,
1260 aio_read_events(ctx, min_nr, nr, event, &ret), 1267 aio_read_events(ctx, min_nr, nr, event, &ret),
1261 until); 1268 until);
1262 1269
1263 if (!ret && signal_pending(current)) 1270 if (!ret && signal_pending(current))
1264 ret = -EINTR; 1271 ret = -EINTR;
1265 1272
1266 return ret; 1273 return ret;
1267 } 1274 }
1268 1275
1269 /* sys_io_setup: 1276 /* sys_io_setup:
1270 * Create an aio_context capable of receiving at least nr_events. 1277 * Create an aio_context capable of receiving at least nr_events.
1271 * ctxp must not point to an aio_context that already exists, and 1278 * ctxp must not point to an aio_context that already exists, and
1272 * must be initialized to 0 prior to the call. On successful 1279 * must be initialized to 0 prior to the call. On successful
1273 * creation of the aio_context, *ctxp is filled in with the resulting 1280 * creation of the aio_context, *ctxp is filled in with the resulting
1274 * handle. May fail with -EINVAL if *ctxp is not initialized, 1281 * handle. May fail with -EINVAL if *ctxp is not initialized,
1275 * if the specified nr_events exceeds internal limits. May fail 1282 * if the specified nr_events exceeds internal limits. May fail
1276 * with -EAGAIN if the specified nr_events exceeds the user's limit 1283 * with -EAGAIN if the specified nr_events exceeds the user's limit
1277 * of available events. May fail with -ENOMEM if insufficient kernel 1284 * of available events. May fail with -ENOMEM if insufficient kernel
1278 * resources are available. May fail with -EFAULT if an invalid 1285 * resources are available. May fail with -EFAULT if an invalid
1279 * pointer is passed for ctxp. Will fail with -ENOSYS if not 1286 * pointer is passed for ctxp. Will fail with -ENOSYS if not
1280 * implemented. 1287 * implemented.
1281 */ 1288 */
1282 SYSCALL_DEFINE2(io_setup, unsigned, nr_events, aio_context_t __user *, ctxp) 1289 SYSCALL_DEFINE2(io_setup, unsigned, nr_events, aio_context_t __user *, ctxp)
1283 { 1290 {
1284 struct kioctx *ioctx = NULL; 1291 struct kioctx *ioctx = NULL;
1285 unsigned long ctx; 1292 unsigned long ctx;
1286 long ret; 1293 long ret;
1287 1294
1288 ret = get_user(ctx, ctxp); 1295 ret = get_user(ctx, ctxp);
1289 if (unlikely(ret)) 1296 if (unlikely(ret))
1290 goto out; 1297 goto out;
1291 1298
1292 ret = -EINVAL; 1299 ret = -EINVAL;
1293 if (unlikely(ctx || nr_events == 0)) { 1300 if (unlikely(ctx || nr_events == 0)) {
1294 pr_debug("EINVAL: io_setup: ctx %lu nr_events %u\n", 1301 pr_debug("EINVAL: io_setup: ctx %lu nr_events %u\n",
1295 ctx, nr_events); 1302 ctx, nr_events);
1296 goto out; 1303 goto out;
1297 } 1304 }
1298 1305
1299 ioctx = ioctx_alloc(nr_events); 1306 ioctx = ioctx_alloc(nr_events);
1300 ret = PTR_ERR(ioctx); 1307 ret = PTR_ERR(ioctx);
1301 if (!IS_ERR(ioctx)) { 1308 if (!IS_ERR(ioctx)) {
1302 ret = put_user(ioctx->user_id, ctxp); 1309 ret = put_user(ioctx->user_id, ctxp);
1303 if (ret) 1310 if (ret)
1304 kill_ioctx(current->mm, ioctx, NULL); 1311 kill_ioctx(current->mm, ioctx, NULL);
1305 percpu_ref_put(&ioctx->users); 1312 percpu_ref_put(&ioctx->users);
1306 } 1313 }
1307 1314
1308 out: 1315 out:
1309 return ret; 1316 return ret;
1310 } 1317 }
1311 1318
1312 /* sys_io_destroy: 1319 /* sys_io_destroy:
1313 * Destroy the aio_context specified. May cancel any outstanding 1320 * Destroy the aio_context specified. May cancel any outstanding
1314 * AIOs and block on completion. Will fail with -ENOSYS if not 1321 * AIOs and block on completion. Will fail with -ENOSYS if not
1315 * implemented. May fail with -EINVAL if the context pointed to 1322 * implemented. May fail with -EINVAL if the context pointed to
1316 * is invalid. 1323 * is invalid.
1317 */ 1324 */
1318 SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx) 1325 SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx)
1319 { 1326 {
1320 struct kioctx *ioctx = lookup_ioctx(ctx); 1327 struct kioctx *ioctx = lookup_ioctx(ctx);
1321 if (likely(NULL != ioctx)) { 1328 if (likely(NULL != ioctx)) {
1322 struct completion requests_done = 1329 struct completion requests_done =
1323 COMPLETION_INITIALIZER_ONSTACK(requests_done); 1330 COMPLETION_INITIALIZER_ONSTACK(requests_done);
1324 int ret; 1331 int ret;
1325 1332
1326 /* Pass requests_done to kill_ioctx() where it can be set 1333 /* Pass requests_done to kill_ioctx() where it can be set
1327 * in a thread-safe way. If we try to set it here then we have 1334 * in a thread-safe way. If we try to set it here then we have
1328 * a race condition if two io_destroy() called simultaneously. 1335 * a race condition if two io_destroy() called simultaneously.
1329 */ 1336 */
1330 ret = kill_ioctx(current->mm, ioctx, &requests_done); 1337 ret = kill_ioctx(current->mm, ioctx, &requests_done);
1331 percpu_ref_put(&ioctx->users); 1338 percpu_ref_put(&ioctx->users);
1332 1339
1333 /* Wait until all IO for the context are done. Otherwise kernel 1340 /* Wait until all IO for the context are done. Otherwise kernel
1334 * keep using user-space buffers even if user thinks the context 1341 * keep using user-space buffers even if user thinks the context
1335 * is destroyed. 1342 * is destroyed.
1336 */ 1343 */
1337 if (!ret) 1344 if (!ret)
1338 wait_for_completion(&requests_done); 1345 wait_for_completion(&requests_done);
1339 1346
1340 return ret; 1347 return ret;
1341 } 1348 }
1342 pr_debug("EINVAL: io_destroy: invalid context id\n"); 1349 pr_debug("EINVAL: io_destroy: invalid context id\n");
1343 return -EINVAL; 1350 return -EINVAL;
1344 } 1351 }
1345 1352
1346 typedef ssize_t (aio_rw_op)(struct kiocb *, const struct iovec *, 1353 typedef ssize_t (aio_rw_op)(struct kiocb *, const struct iovec *,
1347 unsigned long, loff_t); 1354 unsigned long, loff_t);
1348 typedef ssize_t (rw_iter_op)(struct kiocb *, struct iov_iter *); 1355 typedef ssize_t (rw_iter_op)(struct kiocb *, struct iov_iter *);
1349 1356
1350 static ssize_t aio_setup_vectored_rw(struct kiocb *kiocb, 1357 static ssize_t aio_setup_vectored_rw(struct kiocb *kiocb,
1351 int rw, char __user *buf, 1358 int rw, char __user *buf,
1352 unsigned long *nr_segs, 1359 unsigned long *nr_segs,
1353 struct iovec **iovec, 1360 struct iovec **iovec,
1354 bool compat) 1361 bool compat)
1355 { 1362 {
1356 ssize_t ret; 1363 ssize_t ret;
1357 1364
1358 *nr_segs = kiocb->ki_nbytes; 1365 *nr_segs = kiocb->ki_nbytes;
1359 1366
1360 #ifdef CONFIG_COMPAT 1367 #ifdef CONFIG_COMPAT
1361 if (compat) 1368 if (compat)
1362 ret = compat_rw_copy_check_uvector(rw, 1369 ret = compat_rw_copy_check_uvector(rw,
1363 (struct compat_iovec __user *)buf, 1370 (struct compat_iovec __user *)buf,
1364 *nr_segs, UIO_FASTIOV, *iovec, iovec); 1371 *nr_segs, UIO_FASTIOV, *iovec, iovec);
1365 else 1372 else
1366 #endif 1373 #endif
1367 ret = rw_copy_check_uvector(rw, 1374 ret = rw_copy_check_uvector(rw,
1368 (struct iovec __user *)buf, 1375 (struct iovec __user *)buf,
1369 *nr_segs, UIO_FASTIOV, *iovec, iovec); 1376 *nr_segs, UIO_FASTIOV, *iovec, iovec);
1370 if (ret < 0) 1377 if (ret < 0)
1371 return ret; 1378 return ret;
1372 1379
1373 /* ki_nbytes now reflect bytes instead of segs */ 1380 /* ki_nbytes now reflect bytes instead of segs */
1374 kiocb->ki_nbytes = ret; 1381 kiocb->ki_nbytes = ret;
1375 return 0; 1382 return 0;
1376 } 1383 }
1377 1384
1378 static ssize_t aio_setup_single_vector(struct kiocb *kiocb, 1385 static ssize_t aio_setup_single_vector(struct kiocb *kiocb,
1379 int rw, char __user *buf, 1386 int rw, char __user *buf,
1380 unsigned long *nr_segs, 1387 unsigned long *nr_segs,
1381 struct iovec *iovec) 1388 struct iovec *iovec)
1382 { 1389 {
1383 if (unlikely(!access_ok(!rw, buf, kiocb->ki_nbytes))) 1390 if (unlikely(!access_ok(!rw, buf, kiocb->ki_nbytes)))
1384 return -EFAULT; 1391 return -EFAULT;
1385 1392
1386 iovec->iov_base = buf; 1393 iovec->iov_base = buf;
1387 iovec->iov_len = kiocb->ki_nbytes; 1394 iovec->iov_len = kiocb->ki_nbytes;
1388 *nr_segs = 1; 1395 *nr_segs = 1;
1389 return 0; 1396 return 0;
1390 } 1397 }
1391 1398
1392 /* 1399 /*
1393 * aio_run_iocb: 1400 * aio_run_iocb:
1394 * Performs the initial checks and io submission. 1401 * Performs the initial checks and io submission.
1395 */ 1402 */
1396 static ssize_t aio_run_iocb(struct kiocb *req, unsigned opcode, 1403 static ssize_t aio_run_iocb(struct kiocb *req, unsigned opcode,
1397 char __user *buf, bool compat) 1404 char __user *buf, bool compat)
1398 { 1405 {
1399 struct file *file = req->ki_filp; 1406 struct file *file = req->ki_filp;
1400 ssize_t ret; 1407 ssize_t ret;
1401 unsigned long nr_segs; 1408 unsigned long nr_segs;
1402 int rw; 1409 int rw;
1403 fmode_t mode; 1410 fmode_t mode;
1404 aio_rw_op *rw_op; 1411 aio_rw_op *rw_op;
1405 rw_iter_op *iter_op; 1412 rw_iter_op *iter_op;
1406 struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; 1413 struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
1407 struct iov_iter iter; 1414 struct iov_iter iter;
1408 1415
1409 switch (opcode) { 1416 switch (opcode) {
1410 case IOCB_CMD_PREAD: 1417 case IOCB_CMD_PREAD:
1411 case IOCB_CMD_PREADV: 1418 case IOCB_CMD_PREADV:
1412 mode = FMODE_READ; 1419 mode = FMODE_READ;
1413 rw = READ; 1420 rw = READ;
1414 rw_op = file->f_op->aio_read; 1421 rw_op = file->f_op->aio_read;
1415 iter_op = file->f_op->read_iter; 1422 iter_op = file->f_op->read_iter;
1416 goto rw_common; 1423 goto rw_common;
1417 1424
1418 case IOCB_CMD_PWRITE: 1425 case IOCB_CMD_PWRITE:
1419 case IOCB_CMD_PWRITEV: 1426 case IOCB_CMD_PWRITEV:
1420 mode = FMODE_WRITE; 1427 mode = FMODE_WRITE;
1421 rw = WRITE; 1428 rw = WRITE;
1422 rw_op = file->f_op->aio_write; 1429 rw_op = file->f_op->aio_write;
1423 iter_op = file->f_op->write_iter; 1430 iter_op = file->f_op->write_iter;
1424 goto rw_common; 1431 goto rw_common;
1425 rw_common: 1432 rw_common:
1426 if (unlikely(!(file->f_mode & mode))) 1433 if (unlikely(!(file->f_mode & mode)))
1427 return -EBADF; 1434 return -EBADF;
1428 1435
1429 if (!rw_op && !iter_op) 1436 if (!rw_op && !iter_op)
1430 return -EINVAL; 1437 return -EINVAL;
1431 1438
1432 ret = (opcode == IOCB_CMD_PREADV || 1439 ret = (opcode == IOCB_CMD_PREADV ||
1433 opcode == IOCB_CMD_PWRITEV) 1440 opcode == IOCB_CMD_PWRITEV)
1434 ? aio_setup_vectored_rw(req, rw, buf, &nr_segs, 1441 ? aio_setup_vectored_rw(req, rw, buf, &nr_segs,
1435 &iovec, compat) 1442 &iovec, compat)
1436 : aio_setup_single_vector(req, rw, buf, &nr_segs, 1443 : aio_setup_single_vector(req, rw, buf, &nr_segs,
1437 iovec); 1444 iovec);
1438 if (!ret) 1445 if (!ret)
1439 ret = rw_verify_area(rw, file, &req->ki_pos, req->ki_nbytes); 1446 ret = rw_verify_area(rw, file, &req->ki_pos, req->ki_nbytes);
1440 if (ret < 0) { 1447 if (ret < 0) {
1441 if (iovec != inline_vecs) 1448 if (iovec != inline_vecs)
1442 kfree(iovec); 1449 kfree(iovec);
1443 return ret; 1450 return ret;
1444 } 1451 }
1445 1452
1446 req->ki_nbytes = ret; 1453 req->ki_nbytes = ret;
1447 1454
1448 /* XXX: move/kill - rw_verify_area()? */ 1455 /* XXX: move/kill - rw_verify_area()? */
1449 /* This matches the pread()/pwrite() logic */ 1456 /* This matches the pread()/pwrite() logic */
1450 if (req->ki_pos < 0) { 1457 if (req->ki_pos < 0) {
1451 ret = -EINVAL; 1458 ret = -EINVAL;
1452 break; 1459 break;
1453 } 1460 }
1454 1461
1455 if (rw == WRITE) 1462 if (rw == WRITE)
1456 file_start_write(file); 1463 file_start_write(file);
1457 1464
1458 if (iter_op) { 1465 if (iter_op) {
1459 iov_iter_init(&iter, rw, iovec, nr_segs, req->ki_nbytes); 1466 iov_iter_init(&iter, rw, iovec, nr_segs, req->ki_nbytes);
1460 ret = iter_op(req, &iter); 1467 ret = iter_op(req, &iter);
1461 } else { 1468 } else {
1462 ret = rw_op(req, iovec, nr_segs, req->ki_pos); 1469 ret = rw_op(req, iovec, nr_segs, req->ki_pos);
1463 } 1470 }
1464 1471
1465 if (rw == WRITE) 1472 if (rw == WRITE)
1466 file_end_write(file); 1473 file_end_write(file);
1467 break; 1474 break;
1468 1475
1469 case IOCB_CMD_FDSYNC: 1476 case IOCB_CMD_FDSYNC:
1470 if (!file->f_op->aio_fsync) 1477 if (!file->f_op->aio_fsync)
1471 return -EINVAL; 1478 return -EINVAL;
1472 1479
1473 ret = file->f_op->aio_fsync(req, 1); 1480 ret = file->f_op->aio_fsync(req, 1);
1474 break; 1481 break;
1475 1482
1476 case IOCB_CMD_FSYNC: 1483 case IOCB_CMD_FSYNC:
1477 if (!file->f_op->aio_fsync) 1484 if (!file->f_op->aio_fsync)
1478 return -EINVAL; 1485 return -EINVAL;
1479 1486
1480 ret = file->f_op->aio_fsync(req, 0); 1487 ret = file->f_op->aio_fsync(req, 0);
1481 break; 1488 break;
1482 1489
1483 default: 1490 default:
1484 pr_debug("EINVAL: no operation provided\n"); 1491 pr_debug("EINVAL: no operation provided\n");
1485 return -EINVAL; 1492 return -EINVAL;
1486 } 1493 }
1487 1494
1488 if (iovec != inline_vecs) 1495 if (iovec != inline_vecs)
1489 kfree(iovec); 1496 kfree(iovec);
1490 1497
1491 if (ret != -EIOCBQUEUED) { 1498 if (ret != -EIOCBQUEUED) {
1492 /* 1499 /*
1493 * There's no easy way to restart the syscall since other AIO's 1500 * There's no easy way to restart the syscall since other AIO's
1494 * may be already running. Just fail this IO with EINTR. 1501 * may be already running. Just fail this IO with EINTR.
1495 */ 1502 */
1496 if (unlikely(ret == -ERESTARTSYS || ret == -ERESTARTNOINTR || 1503 if (unlikely(ret == -ERESTARTSYS || ret == -ERESTARTNOINTR ||
1497 ret == -ERESTARTNOHAND || 1504 ret == -ERESTARTNOHAND ||
1498 ret == -ERESTART_RESTARTBLOCK)) 1505 ret == -ERESTART_RESTARTBLOCK))
1499 ret = -EINTR; 1506 ret = -EINTR;
1500 aio_complete(req, ret, 0); 1507 aio_complete(req, ret, 0);
1501 } 1508 }
1502 1509
1503 return 0; 1510 return 0;
1504 } 1511 }
1505 1512
1506 static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, 1513 static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
1507 struct iocb *iocb, bool compat) 1514 struct iocb *iocb, bool compat)
1508 { 1515 {
1509 struct kiocb *req; 1516 struct kiocb *req;
1510 ssize_t ret; 1517 ssize_t ret;
1511 1518
1512 /* enforce forwards compatibility on users */ 1519 /* enforce forwards compatibility on users */
1513 if (unlikely(iocb->aio_reserved1 || iocb->aio_reserved2)) { 1520 if (unlikely(iocb->aio_reserved1 || iocb->aio_reserved2)) {
1514 pr_debug("EINVAL: reserve field set\n"); 1521 pr_debug("EINVAL: reserve field set\n");
1515 return -EINVAL; 1522 return -EINVAL;
1516 } 1523 }
1517 1524
1518 /* prevent overflows */ 1525 /* prevent overflows */
1519 if (unlikely( 1526 if (unlikely(
1520 (iocb->aio_buf != (unsigned long)iocb->aio_buf) || 1527 (iocb->aio_buf != (unsigned long)iocb->aio_buf) ||
1521 (iocb->aio_nbytes != (size_t)iocb->aio_nbytes) || 1528 (iocb->aio_nbytes != (size_t)iocb->aio_nbytes) ||
1522 ((ssize_t)iocb->aio_nbytes < 0) 1529 ((ssize_t)iocb->aio_nbytes < 0)
1523 )) { 1530 )) {
1524 pr_debug("EINVAL: io_submit: overflow check\n"); 1531 pr_debug("EINVAL: io_submit: overflow check\n");
1525 return -EINVAL; 1532 return -EINVAL;
1526 } 1533 }
1527 1534
1528 req = aio_get_req(ctx); 1535 req = aio_get_req(ctx);
1529 if (unlikely(!req)) 1536 if (unlikely(!req))
1530 return -EAGAIN; 1537 return -EAGAIN;
1531 1538
1532 req->ki_filp = fget(iocb->aio_fildes); 1539 req->ki_filp = fget(iocb->aio_fildes);
1533 if (unlikely(!req->ki_filp)) { 1540 if (unlikely(!req->ki_filp)) {
1534 ret = -EBADF; 1541 ret = -EBADF;
1535 goto out_put_req; 1542 goto out_put_req;
1536 } 1543 }
1537 1544
1538 if (iocb->aio_flags & IOCB_FLAG_RESFD) { 1545 if (iocb->aio_flags & IOCB_FLAG_RESFD) {
1539 /* 1546 /*
1540 * If the IOCB_FLAG_RESFD flag of aio_flags is set, get an 1547 * If the IOCB_FLAG_RESFD flag of aio_flags is set, get an
1541 * instance of the file* now. The file descriptor must be 1548 * instance of the file* now. The file descriptor must be
1542 * an eventfd() fd, and will be signaled for each completed 1549 * an eventfd() fd, and will be signaled for each completed
1543 * event using the eventfd_signal() function. 1550 * event using the eventfd_signal() function.
1544 */ 1551 */
1545 req->ki_eventfd = eventfd_ctx_fdget((int) iocb->aio_resfd); 1552 req->ki_eventfd = eventfd_ctx_fdget((int) iocb->aio_resfd);
1546 if (IS_ERR(req->ki_eventfd)) { 1553 if (IS_ERR(req->ki_eventfd)) {
1547 ret = PTR_ERR(req->ki_eventfd); 1554 ret = PTR_ERR(req->ki_eventfd);
1548 req->ki_eventfd = NULL; 1555 req->ki_eventfd = NULL;
1549 goto out_put_req; 1556 goto out_put_req;
1550 } 1557 }
1551 } 1558 }
1552 1559
1553 ret = put_user(KIOCB_KEY, &user_iocb->aio_key); 1560 ret = put_user(KIOCB_KEY, &user_iocb->aio_key);
1554 if (unlikely(ret)) { 1561 if (unlikely(ret)) {
1555 pr_debug("EFAULT: aio_key\n"); 1562 pr_debug("EFAULT: aio_key\n");
1556 goto out_put_req; 1563 goto out_put_req;
1557 } 1564 }
1558 1565
1559 req->ki_obj.user = user_iocb; 1566 req->ki_obj.user = user_iocb;
1560 req->ki_user_data = iocb->aio_data; 1567 req->ki_user_data = iocb->aio_data;
1561 req->ki_pos = iocb->aio_offset; 1568 req->ki_pos = iocb->aio_offset;
1562 req->ki_nbytes = iocb->aio_nbytes; 1569 req->ki_nbytes = iocb->aio_nbytes;
1563 1570
1564 ret = aio_run_iocb(req, iocb->aio_lio_opcode, 1571 ret = aio_run_iocb(req, iocb->aio_lio_opcode,
1565 (char __user *)(unsigned long)iocb->aio_buf, 1572 (char __user *)(unsigned long)iocb->aio_buf,
1566 compat); 1573 compat);
1567 if (ret) 1574 if (ret)
1568 goto out_put_req; 1575 goto out_put_req;
1569 1576
1570 return 0; 1577 return 0;
1571 out_put_req: 1578 out_put_req:
1572 put_reqs_available(ctx, 1); 1579 put_reqs_available(ctx, 1);
1573 percpu_ref_put(&ctx->reqs); 1580 percpu_ref_put(&ctx->reqs);
1574 kiocb_free(req); 1581 kiocb_free(req);
1575 return ret; 1582 return ret;
1576 } 1583 }
1577 1584
1578 long do_io_submit(aio_context_t ctx_id, long nr, 1585 long do_io_submit(aio_context_t ctx_id, long nr,
1579 struct iocb __user *__user *iocbpp, bool compat) 1586 struct iocb __user *__user *iocbpp, bool compat)
1580 { 1587 {
1581 struct kioctx *ctx; 1588 struct kioctx *ctx;
1582 long ret = 0; 1589 long ret = 0;
1583 int i = 0; 1590 int i = 0;
1584 struct blk_plug plug; 1591 struct blk_plug plug;
1585 1592
1586 if (unlikely(nr < 0)) 1593 if (unlikely(nr < 0))
1587 return -EINVAL; 1594 return -EINVAL;
1588 1595
1589 if (unlikely(nr > LONG_MAX/sizeof(*iocbpp))) 1596 if (unlikely(nr > LONG_MAX/sizeof(*iocbpp)))
1590 nr = LONG_MAX/sizeof(*iocbpp); 1597 nr = LONG_MAX/sizeof(*iocbpp);
1591 1598
1592 if (unlikely(!access_ok(VERIFY_READ, iocbpp, (nr*sizeof(*iocbpp))))) 1599 if (unlikely(!access_ok(VERIFY_READ, iocbpp, (nr*sizeof(*iocbpp)))))
1593 return -EFAULT; 1600 return -EFAULT;
1594 1601
1595 ctx = lookup_ioctx(ctx_id); 1602 ctx = lookup_ioctx(ctx_id);
1596 if (unlikely(!ctx)) { 1603 if (unlikely(!ctx)) {
1597 pr_debug("EINVAL: invalid context id\n"); 1604 pr_debug("EINVAL: invalid context id\n");
1598 return -EINVAL; 1605 return -EINVAL;
1599 } 1606 }
1600 1607
1601 blk_start_plug(&plug); 1608 blk_start_plug(&plug);
1602 1609
1603 /* 1610 /*
1604 * AKPM: should this return a partial result if some of the IOs were 1611 * AKPM: should this return a partial result if some of the IOs were
1605 * successfully submitted? 1612 * successfully submitted?
1606 */ 1613 */
1607 for (i=0; i<nr; i++) { 1614 for (i=0; i<nr; i++) {
1608 struct iocb __user *user_iocb; 1615 struct iocb __user *user_iocb;
1609 struct iocb tmp; 1616 struct iocb tmp;
1610 1617
1611 if (unlikely(__get_user(user_iocb, iocbpp + i))) { 1618 if (unlikely(__get_user(user_iocb, iocbpp + i))) {
1612 ret = -EFAULT; 1619 ret = -EFAULT;
1613 break; 1620 break;
1614 } 1621 }
1615 1622
1616 if (unlikely(copy_from_user(&tmp, user_iocb, sizeof(tmp)))) { 1623 if (unlikely(copy_from_user(&tmp, user_iocb, sizeof(tmp)))) {
1617 ret = -EFAULT; 1624 ret = -EFAULT;
1618 break; 1625 break;
1619 } 1626 }
1620 1627
1621 ret = io_submit_one(ctx, user_iocb, &tmp, compat); 1628 ret = io_submit_one(ctx, user_iocb, &tmp, compat);
1622 if (ret) 1629 if (ret)
1623 break; 1630 break;
1624 } 1631 }
1625 blk_finish_plug(&plug); 1632 blk_finish_plug(&plug);
1626 1633
1627 percpu_ref_put(&ctx->users); 1634 percpu_ref_put(&ctx->users);
1628 return i ? i : ret; 1635 return i ? i : ret;
1629 } 1636 }
1630 1637
1631 /* sys_io_submit: 1638 /* sys_io_submit:
1632 * Queue the nr iocbs pointed to by iocbpp for processing. Returns 1639 * Queue the nr iocbs pointed to by iocbpp for processing. Returns
1633 * the number of iocbs queued. May return -EINVAL if the aio_context 1640 * the number of iocbs queued. May return -EINVAL if the aio_context
1634 * specified by ctx_id is invalid, if nr is < 0, if the iocb at 1641 * specified by ctx_id is invalid, if nr is < 0, if the iocb at
1635 * *iocbpp[0] is not properly initialized, if the operation specified 1642 * *iocbpp[0] is not properly initialized, if the operation specified
1636 * is invalid for the file descriptor in the iocb. May fail with 1643 * is invalid for the file descriptor in the iocb. May fail with
1637 * -EFAULT if any of the data structures point to invalid data. May 1644 * -EFAULT if any of the data structures point to invalid data. May
1638 * fail with -EBADF if the file descriptor specified in the first 1645 * fail with -EBADF if the file descriptor specified in the first
1639 * iocb is invalid. May fail with -EAGAIN if insufficient resources 1646 * iocb is invalid. May fail with -EAGAIN if insufficient resources
1640 * are available to queue any iocbs. Will return 0 if nr is 0. Will 1647 * are available to queue any iocbs. Will return 0 if nr is 0. Will
1641 * fail with -ENOSYS if not implemented. 1648 * fail with -ENOSYS if not implemented.
1642 */ 1649 */
1643 SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr, 1650 SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr,
1644 struct iocb __user * __user *, iocbpp) 1651 struct iocb __user * __user *, iocbpp)
1645 { 1652 {
1646 return do_io_submit(ctx_id, nr, iocbpp, 0); 1653 return do_io_submit(ctx_id, nr, iocbpp, 0);
1647 } 1654 }
1648 1655
1649 /* lookup_kiocb 1656 /* lookup_kiocb
1650 * Finds a given iocb for cancellation. 1657 * Finds a given iocb for cancellation.
1651 */ 1658 */
1652 static struct kiocb *lookup_kiocb(struct kioctx *ctx, struct iocb __user *iocb, 1659 static struct kiocb *lookup_kiocb(struct kioctx *ctx, struct iocb __user *iocb,
1653 u32 key) 1660 u32 key)
1654 { 1661 {
1655 struct list_head *pos; 1662 struct list_head *pos;
1656 1663
1657 assert_spin_locked(&ctx->ctx_lock); 1664 assert_spin_locked(&ctx->ctx_lock);
1658 1665
1659 if (key != KIOCB_KEY) 1666 if (key != KIOCB_KEY)
1660 return NULL; 1667 return NULL;
1661 1668
1662 /* TODO: use a hash or array, this sucks. */ 1669 /* TODO: use a hash or array, this sucks. */
1663 list_for_each(pos, &ctx->active_reqs) { 1670 list_for_each(pos, &ctx->active_reqs) {
1664 struct kiocb *kiocb = list_kiocb(pos); 1671 struct kiocb *kiocb = list_kiocb(pos);
1665 if (kiocb->ki_obj.user == iocb) 1672 if (kiocb->ki_obj.user == iocb)
1666 return kiocb; 1673 return kiocb;
1667 } 1674 }
1668 return NULL; 1675 return NULL;
1669 } 1676 }
1670 1677
1671 /* sys_io_cancel: 1678 /* sys_io_cancel:
1672 * Attempts to cancel an iocb previously passed to io_submit. If 1679 * Attempts to cancel an iocb previously passed to io_submit. If
1673 * the operation is successfully cancelled, the resulting event is 1680 * the operation is successfully cancelled, the resulting event is
1674 * copied into the memory pointed to by result without being placed 1681 * copied into the memory pointed to by result without being placed
1675 * into the completion queue and 0 is returned. May fail with 1682 * into the completion queue and 0 is returned. May fail with
1676 * -EFAULT if any of the data structures pointed to are invalid. 1683 * -EFAULT if any of the data structures pointed to are invalid.
1677 * May fail with -EINVAL if aio_context specified by ctx_id is 1684 * May fail with -EINVAL if aio_context specified by ctx_id is
1678 * invalid. May fail with -EAGAIN if the iocb specified was not 1685 * invalid. May fail with -EAGAIN if the iocb specified was not
1679 * cancelled. Will fail with -ENOSYS if not implemented. 1686 * cancelled. Will fail with -ENOSYS if not implemented.
1680 */ 1687 */
1681 SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb, 1688 SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
1682 struct io_event __user *, result) 1689 struct io_event __user *, result)
1683 { 1690 {
1684 struct kioctx *ctx; 1691 struct kioctx *ctx;
1685 struct kiocb *kiocb; 1692 struct kiocb *kiocb;
1686 u32 key; 1693 u32 key;
1687 int ret; 1694 int ret;
1688 1695
1689 ret = get_user(key, &iocb->aio_key); 1696 ret = get_user(key, &iocb->aio_key);
1690 if (unlikely(ret)) 1697 if (unlikely(ret))
1691 return -EFAULT; 1698 return -EFAULT;
1692 1699
1693 ctx = lookup_ioctx(ctx_id); 1700 ctx = lookup_ioctx(ctx_id);
1694 if (unlikely(!ctx)) 1701 if (unlikely(!ctx))
1695 return -EINVAL; 1702 return -EINVAL;
1696 1703
1697 spin_lock_irq(&ctx->ctx_lock); 1704 spin_lock_irq(&ctx->ctx_lock);
1698 1705
1699 kiocb = lookup_kiocb(ctx, iocb, key); 1706 kiocb = lookup_kiocb(ctx, iocb, key);
1700 if (kiocb) 1707 if (kiocb)
1701 ret = kiocb_cancel(kiocb); 1708 ret = kiocb_cancel(kiocb);
1702 else 1709 else
1703 ret = -EINVAL; 1710 ret = -EINVAL;
1704 1711
1705 spin_unlock_irq(&ctx->ctx_lock); 1712 spin_unlock_irq(&ctx->ctx_lock);
1706 1713
1707 if (!ret) { 1714 if (!ret) {
1708 /* 1715 /*
1709 * The result argument is no longer used - the io_event is 1716 * The result argument is no longer used - the io_event is
1710 * always delivered via the ring buffer. -EINPROGRESS indicates 1717 * always delivered via the ring buffer. -EINPROGRESS indicates
1711 * cancellation is progress: 1718 * cancellation is progress:
1712 */ 1719 */
1713 ret = -EINPROGRESS; 1720 ret = -EINPROGRESS;
1714 } 1721 }
1715 1722
1716 percpu_ref_put(&ctx->users); 1723 percpu_ref_put(&ctx->users);
1717 1724
1718 return ret; 1725 return ret;
1719 } 1726 }
1720 1727
1721 /* io_getevents: 1728 /* io_getevents:
1722 * Attempts to read at least min_nr events and up to nr events from 1729 * Attempts to read at least min_nr events and up to nr events from
1723 * the completion queue for the aio_context specified by ctx_id. If 1730 * the completion queue for the aio_context specified by ctx_id. If
1724 * it succeeds, the number of read events is returned. May fail with 1731 * it succeeds, the number of read events is returned. May fail with
1725 * -EINVAL if ctx_id is invalid, if min_nr is out of range, if nr is 1732 * -EINVAL if ctx_id is invalid, if min_nr is out of range, if nr is
1726 * out of range, if timeout is out of range. May fail with -EFAULT 1733 * out of range, if timeout is out of range. May fail with -EFAULT
1727 * if any of the memory specified is invalid. May return 0 or 1734 * if any of the memory specified is invalid. May return 0 or
1728 * < min_nr if the timeout specified by timeout has elapsed 1735 * < min_nr if the timeout specified by timeout has elapsed
1729 * before sufficient events are available, where timeout == NULL 1736 * before sufficient events are available, where timeout == NULL
1730 * specifies an infinite timeout. Note that the timeout pointed to by 1737 * specifies an infinite timeout. Note that the timeout pointed to by
1731 * timeout is relative. Will fail with -ENOSYS if not implemented. 1738 * timeout is relative. Will fail with -ENOSYS if not implemented.
1732 */ 1739 */
1733 SYSCALL_DEFINE5(io_getevents, aio_context_t, ctx_id, 1740 SYSCALL_DEFINE5(io_getevents, aio_context_t, ctx_id,
1734 long, min_nr, 1741 long, min_nr,
1735 long, nr, 1742 long, nr,
1736 struct io_event __user *, events, 1743 struct io_event __user *, events,
1737 struct timespec __user *, timeout) 1744 struct timespec __user *, timeout)
1738 { 1745 {
1739 struct kioctx *ioctx = lookup_ioctx(ctx_id); 1746 struct kioctx *ioctx = lookup_ioctx(ctx_id);
1740 long ret = -EINVAL; 1747 long ret = -EINVAL;
1741 1748
1742 if (likely(ioctx)) { 1749 if (likely(ioctx)) {
1743 if (likely(min_nr <= nr && min_nr >= 0)) 1750 if (likely(min_nr <= nr && min_nr >= 0))
1744 ret = read_events(ioctx, min_nr, nr, events, timeout); 1751 ret = read_events(ioctx, min_nr, nr, events, timeout);
1745 percpu_ref_put(&ioctx->users); 1752 percpu_ref_put(&ioctx->users);
1746 } 1753 }
1747 return ret; 1754 return ret;
1748 } 1755 }
1749 1756