Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * An async IO implementation for Linux |
| 3 | * Written by Benjamin LaHaise <bcrl@kvack.org> |
| 4 | * |
| 5 | * Implements an efficient asynchronous io interface. |
| 6 | * |
| 7 | * Copyright 2000, 2001, 2002 Red Hat, Inc. All Rights Reserved. |
| 8 | * |
| 9 | * See ../COPYING for licensing terms. |
| 10 | */ |
Kent Overstreet | caf4167 | 2013-05-07 16:18:35 -0700 | [diff] [blame] | 11 | #define pr_fmt(fmt) "%s: " fmt, __func__ |
| 12 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <linux/kernel.h> |
| 14 | #include <linux/init.h> |
| 15 | #include <linux/errno.h> |
| 16 | #include <linux/time.h> |
| 17 | #include <linux/aio_abi.h> |
Paul Gortmaker | 630d9c4 | 2011-11-16 23:57:37 -0500 | [diff] [blame] | 18 | #include <linux/export.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | #include <linux/syscalls.h> |
Jens Axboe | b9d128f | 2009-10-29 13:59:26 +0100 | [diff] [blame] | 20 | #include <linux/backing-dev.h> |
Badari Pulavarty | 027445c | 2006-09-30 23:28:46 -0700 | [diff] [blame] | 21 | #include <linux/uio.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | #include <linux/sched.h> |
| 24 | #include <linux/fs.h> |
| 25 | #include <linux/file.h> |
| 26 | #include <linux/mm.h> |
| 27 | #include <linux/mman.h> |
Michael S. Tsirkin | 3d2d827 | 2009-09-21 17:03:51 -0700 | [diff] [blame] | 28 | #include <linux/mmu_context.h> |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 29 | #include <linux/percpu.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | #include <linux/slab.h> |
| 31 | #include <linux/timer.h> |
| 32 | #include <linux/aio.h> |
| 33 | #include <linux/highmem.h> |
| 34 | #include <linux/workqueue.h> |
| 35 | #include <linux/security.h> |
Davide Libenzi | 9c3060b | 2007-05-10 22:23:21 -0700 | [diff] [blame] | 36 | #include <linux/eventfd.h> |
Jeff Moyer | cfb1e33 | 2009-10-02 18:57:36 -0400 | [diff] [blame] | 37 | #include <linux/blkdev.h> |
Jeff Moyer | 9d85cba | 2010-05-26 14:44:26 -0700 | [diff] [blame] | 38 | #include <linux/compat.h> |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 39 | #include <linux/migrate.h> |
| 40 | #include <linux/ramfs.h> |
Kent Overstreet | 723be6e | 2013-05-28 15:14:48 -0700 | [diff] [blame] | 41 | #include <linux/percpu-refcount.h> |
Benjamin LaHaise | 71ad749 | 2013-09-17 10:18:25 -0400 | [diff] [blame] | 42 | #include <linux/mount.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | |
| 44 | #include <asm/kmap_types.h> |
| 45 | #include <asm/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | |
Al Viro | 68d70d0 | 2013-06-19 15:26:04 +0400 | [diff] [blame] | 47 | #include "internal.h" |
| 48 | |
Kent Overstreet | 4e179bc | 2013-05-07 16:18:33 -0700 | [diff] [blame] | 49 | #define AIO_RING_MAGIC 0xa10a10a1 |
| 50 | #define AIO_RING_COMPAT_FEATURES 1 |
| 51 | #define AIO_RING_INCOMPAT_FEATURES 0 |
| 52 | struct aio_ring { |
| 53 | unsigned id; /* kernel internal index number */ |
| 54 | unsigned nr; /* number of io_events */ |
Benjamin LaHaise | fa8a53c | 2014-03-28 10:14:45 -0400 | [diff] [blame] | 55 | unsigned head; /* Written to by userland or under ring_lock |
| 56 | * mutex by aio_read_events_ring(). */ |
Kent Overstreet | 4e179bc | 2013-05-07 16:18:33 -0700 | [diff] [blame] | 57 | unsigned tail; |
| 58 | |
| 59 | unsigned magic; |
| 60 | unsigned compat_features; |
| 61 | unsigned incompat_features; |
| 62 | unsigned header_length; /* size of aio_ring */ |
| 63 | |
| 64 | |
| 65 | struct io_event io_events[0]; |
| 66 | }; /* 128 bytes + ring size */ |
| 67 | |
| 68 | #define AIO_RING_PAGES 8 |
Kent Overstreet | 4e179bc | 2013-05-07 16:18:33 -0700 | [diff] [blame] | 69 | |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 70 | struct kioctx_table { |
| 71 | struct rcu_head rcu; |
| 72 | unsigned nr; |
| 73 | struct kioctx *table[]; |
| 74 | }; |
| 75 | |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 76 | struct kioctx_cpu { |
| 77 | unsigned reqs_available; |
| 78 | }; |
| 79 | |
Kent Overstreet | 4e179bc | 2013-05-07 16:18:33 -0700 | [diff] [blame] | 80 | struct kioctx { |
Kent Overstreet | 723be6e | 2013-05-28 15:14:48 -0700 | [diff] [blame] | 81 | struct percpu_ref users; |
Kent Overstreet | 36f5588 | 2013-05-07 16:18:41 -0700 | [diff] [blame] | 82 | atomic_t dead; |
Kent Overstreet | 4e179bc | 2013-05-07 16:18:33 -0700 | [diff] [blame] | 83 | |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 84 | struct percpu_ref reqs; |
| 85 | |
Kent Overstreet | 4e179bc | 2013-05-07 16:18:33 -0700 | [diff] [blame] | 86 | unsigned long user_id; |
Kent Overstreet | 4e179bc | 2013-05-07 16:18:33 -0700 | [diff] [blame] | 87 | |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 88 | struct __percpu kioctx_cpu *cpu; |
| 89 | |
| 90 | /* |
| 91 | * For percpu reqs_available, number of slots we move to/from global |
| 92 | * counter at a time: |
| 93 | */ |
| 94 | unsigned req_batch; |
Kent Overstreet | 3e845ce | 2013-05-07 16:18:51 -0700 | [diff] [blame] | 95 | /* |
| 96 | * This is what userspace passed to io_setup(), it's not used for |
| 97 | * anything but counting against the global max_reqs quota. |
| 98 | * |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 99 | * The real limit is nr_events - 1, which will be larger (see |
Kent Overstreet | 3e845ce | 2013-05-07 16:18:51 -0700 | [diff] [blame] | 100 | * aio_setup_ring()) |
| 101 | */ |
Kent Overstreet | 4e179bc | 2013-05-07 16:18:33 -0700 | [diff] [blame] | 102 | unsigned max_reqs; |
| 103 | |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 104 | /* Size of ringbuffer, in units of struct io_event */ |
| 105 | unsigned nr_events; |
Kent Overstreet | 4e179bc | 2013-05-07 16:18:33 -0700 | [diff] [blame] | 106 | |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 107 | unsigned long mmap_base; |
| 108 | unsigned long mmap_size; |
| 109 | |
| 110 | struct page **ring_pages; |
| 111 | long nr_pages; |
| 112 | |
Kent Overstreet | 723be6e | 2013-05-28 15:14:48 -0700 | [diff] [blame] | 113 | struct work_struct free_work; |
Kent Overstreet | 4e23bca | 2013-05-07 16:18:56 -0700 | [diff] [blame] | 114 | |
Anatol Pomozov | e02ba72 | 2014-04-15 11:31:33 -0700 | [diff] [blame] | 115 | /* |
| 116 | * signals when all in-flight requests are done |
| 117 | */ |
| 118 | struct completion *requests_done; |
| 119 | |
Kent Overstreet | 4e23bca | 2013-05-07 16:18:56 -0700 | [diff] [blame] | 120 | struct { |
Kent Overstreet | 34e83fc | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 121 | /* |
| 122 | * This counts the number of available slots in the ringbuffer, |
| 123 | * so we avoid overflowing it: it's decremented (if positive) |
| 124 | * when allocating a kiocb and incremented when the resulting |
| 125 | * io_event is pulled off the ringbuffer. |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 126 | * |
| 127 | * We batch accesses to it with a percpu version. |
Kent Overstreet | 34e83fc | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 128 | */ |
| 129 | atomic_t reqs_available; |
Kent Overstreet | 4e23bca | 2013-05-07 16:18:56 -0700 | [diff] [blame] | 130 | } ____cacheline_aligned_in_smp; |
| 131 | |
| 132 | struct { |
| 133 | spinlock_t ctx_lock; |
| 134 | struct list_head active_reqs; /* used for cancellation */ |
| 135 | } ____cacheline_aligned_in_smp; |
| 136 | |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 137 | struct { |
| 138 | struct mutex ring_lock; |
Kent Overstreet | 4e23bca | 2013-05-07 16:18:56 -0700 | [diff] [blame] | 139 | wait_queue_head_t wait; |
| 140 | } ____cacheline_aligned_in_smp; |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 141 | |
| 142 | struct { |
| 143 | unsigned tail; |
Benjamin LaHaise | d856f32 | 2014-08-24 13:14:05 -0400 | [diff] [blame] | 144 | unsigned completed_events; |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 145 | spinlock_t completion_lock; |
Kent Overstreet | 4e23bca | 2013-05-07 16:18:56 -0700 | [diff] [blame] | 146 | } ____cacheline_aligned_in_smp; |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 147 | |
| 148 | struct page *internal_pages[AIO_RING_PAGES]; |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 149 | struct file *aio_ring_file; |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 150 | |
| 151 | unsigned id; |
Kent Overstreet | 4e179bc | 2013-05-07 16:18:33 -0700 | [diff] [blame] | 152 | }; |
| 153 | |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 154 | /* |
| 155 | * We use ki_cancel == KIOCB_CANCELLED to indicate that a kiocb has been either |
| 156 | * cancelled or completed (this makes a certain amount of sense because |
| 157 | * successful cancellation - io_cancel() - does deliver the completion to |
| 158 | * userspace). |
| 159 | * |
| 160 | * And since most things don't implement kiocb cancellation and we'd really like |
| 161 | * kiocb completion to be lockless when possible, we use ki_cancel to |
| 162 | * synchronize cancellation and completion - we only set it to KIOCB_CANCELLED |
| 163 | * with xchg() or cmpxchg(), see batch_complete_aio() and kiocb_cancel(). |
| 164 | */ |
| 165 | #define KIOCB_CANCELLED ((void *) (~0ULL)) |
| 166 | |
| 167 | struct aio_kiocb { |
| 168 | struct kiocb common; |
| 169 | |
| 170 | struct kioctx *ki_ctx; |
| 171 | kiocb_cancel_fn *ki_cancel; |
| 172 | |
| 173 | struct iocb __user *ki_user_iocb; /* user's aiocb */ |
| 174 | __u64 ki_user_data; /* user's data for completion */ |
| 175 | |
| 176 | struct list_head ki_list; /* the aio core uses this |
| 177 | * for cancellation */ |
| 178 | |
| 179 | /* |
| 180 | * If the aio_resfd field of the userspace iocb is not zero, |
| 181 | * this is the underlying eventfd context to deliver events to. |
| 182 | */ |
| 183 | struct eventfd_ctx *ki_eventfd; |
| 184 | }; |
| 185 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | /*------ sysctl variables----*/ |
Zach Brown | d55b5fd | 2005-11-07 00:59:31 -0800 | [diff] [blame] | 187 | static DEFINE_SPINLOCK(aio_nr_lock); |
| 188 | unsigned long aio_nr; /* current system wide number of aio requests */ |
| 189 | unsigned long aio_max_nr = 0x10000; /* system wide maximum number of aio requests */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | /*----end sysctl variables---*/ |
| 191 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 192 | static struct kmem_cache *kiocb_cachep; |
| 193 | static struct kmem_cache *kioctx_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 194 | |
Benjamin LaHaise | 71ad749 | 2013-09-17 10:18:25 -0400 | [diff] [blame] | 195 | static struct vfsmount *aio_mnt; |
| 196 | |
| 197 | static const struct file_operations aio_ring_fops; |
| 198 | static const struct address_space_operations aio_ctx_aops; |
| 199 | |
| 200 | static struct file *aio_private_file(struct kioctx *ctx, loff_t nr_pages) |
| 201 | { |
| 202 | struct qstr this = QSTR_INIT("[aio]", 5); |
| 203 | struct file *file; |
| 204 | struct path path; |
| 205 | struct inode *inode = alloc_anon_inode(aio_mnt->mnt_sb); |
Dan Carpenter | 7f62656 | 2013-11-13 10:49:40 +0300 | [diff] [blame] | 206 | if (IS_ERR(inode)) |
| 207 | return ERR_CAST(inode); |
Benjamin LaHaise | 71ad749 | 2013-09-17 10:18:25 -0400 | [diff] [blame] | 208 | |
| 209 | inode->i_mapping->a_ops = &aio_ctx_aops; |
| 210 | inode->i_mapping->private_data = ctx; |
| 211 | inode->i_size = PAGE_SIZE * nr_pages; |
| 212 | |
| 213 | path.dentry = d_alloc_pseudo(aio_mnt->mnt_sb, &this); |
| 214 | if (!path.dentry) { |
| 215 | iput(inode); |
| 216 | return ERR_PTR(-ENOMEM); |
| 217 | } |
| 218 | path.mnt = mntget(aio_mnt); |
| 219 | |
| 220 | d_instantiate(path.dentry, inode); |
| 221 | file = alloc_file(&path, FMODE_READ | FMODE_WRITE, &aio_ring_fops); |
| 222 | if (IS_ERR(file)) { |
| 223 | path_put(&path); |
| 224 | return file; |
| 225 | } |
| 226 | |
| 227 | file->f_flags = O_RDWR; |
Benjamin LaHaise | 71ad749 | 2013-09-17 10:18:25 -0400 | [diff] [blame] | 228 | return file; |
| 229 | } |
| 230 | |
| 231 | static struct dentry *aio_mount(struct file_system_type *fs_type, |
| 232 | int flags, const char *dev_name, void *data) |
| 233 | { |
| 234 | static const struct dentry_operations ops = { |
| 235 | .d_dname = simple_dname, |
| 236 | }; |
Gu Zheng | 8dc4379 | 2014-07-23 18:03:52 +0800 | [diff] [blame] | 237 | return mount_pseudo(fs_type, "aio:", NULL, &ops, AIO_RING_MAGIC); |
Benjamin LaHaise | 71ad749 | 2013-09-17 10:18:25 -0400 | [diff] [blame] | 238 | } |
| 239 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | /* aio_setup |
| 241 | * Creates the slab caches used by the aio routines, panic on |
| 242 | * failure as this is done early during the boot sequence. |
| 243 | */ |
| 244 | static int __init aio_setup(void) |
| 245 | { |
Benjamin LaHaise | 71ad749 | 2013-09-17 10:18:25 -0400 | [diff] [blame] | 246 | static struct file_system_type aio_fs = { |
| 247 | .name = "aio", |
| 248 | .mount = aio_mount, |
| 249 | .kill_sb = kill_anon_super, |
| 250 | }; |
| 251 | aio_mnt = kern_mount(&aio_fs); |
| 252 | if (IS_ERR(aio_mnt)) |
| 253 | panic("Failed to create aio fs mount."); |
| 254 | |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 255 | kiocb_cachep = KMEM_CACHE(aio_kiocb, SLAB_HWCACHE_ALIGN|SLAB_PANIC); |
Christoph Lameter | 0a31bd5 | 2007-05-06 14:49:57 -0700 | [diff] [blame] | 256 | kioctx_cachep = KMEM_CACHE(kioctx,SLAB_HWCACHE_ALIGN|SLAB_PANIC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | |
Kent Overstreet | caf4167 | 2013-05-07 16:18:35 -0700 | [diff] [blame] | 258 | pr_debug("sizeof(struct page) = %zu\n", sizeof(struct page)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 259 | |
| 260 | return 0; |
| 261 | } |
H Hartley Sweeten | 385773e | 2009-09-22 16:43:53 -0700 | [diff] [blame] | 262 | __initcall(aio_setup); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 263 | |
Benjamin LaHaise | 5e9ae2e | 2013-09-26 20:34:51 -0400 | [diff] [blame] | 264 | static void put_aio_ring_file(struct kioctx *ctx) |
| 265 | { |
| 266 | struct file *aio_ring_file = ctx->aio_ring_file; |
| 267 | if (aio_ring_file) { |
| 268 | truncate_setsize(aio_ring_file->f_inode, 0); |
| 269 | |
| 270 | /* Prevent further access to the kioctx from migratepages */ |
| 271 | spin_lock(&aio_ring_file->f_inode->i_mapping->private_lock); |
| 272 | aio_ring_file->f_inode->i_mapping->private_data = NULL; |
| 273 | ctx->aio_ring_file = NULL; |
| 274 | spin_unlock(&aio_ring_file->f_inode->i_mapping->private_lock); |
| 275 | |
| 276 | fput(aio_ring_file); |
| 277 | } |
| 278 | } |
| 279 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | static void aio_free_ring(struct kioctx *ctx) |
| 281 | { |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 282 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 283 | |
Benjamin LaHaise | fa8a53c | 2014-03-28 10:14:45 -0400 | [diff] [blame] | 284 | /* Disconnect the kiotx from the ring file. This prevents future |
| 285 | * accesses to the kioctx from page migration. |
| 286 | */ |
| 287 | put_aio_ring_file(ctx); |
| 288 | |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 289 | for (i = 0; i < ctx->nr_pages; i++) { |
Benjamin LaHaise | 8e321fe | 2013-12-21 17:56:08 -0500 | [diff] [blame] | 290 | struct page *page; |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 291 | pr_debug("pid(%d) [%d] page->count=%d\n", current->pid, i, |
| 292 | page_count(ctx->ring_pages[i])); |
Benjamin LaHaise | 8e321fe | 2013-12-21 17:56:08 -0500 | [diff] [blame] | 293 | page = ctx->ring_pages[i]; |
| 294 | if (!page) |
| 295 | continue; |
| 296 | ctx->ring_pages[i] = NULL; |
| 297 | put_page(page); |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 298 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 299 | |
Sasha Levin | ddb8c45 | 2013-11-19 17:33:03 -0500 | [diff] [blame] | 300 | if (ctx->ring_pages && ctx->ring_pages != ctx->internal_pages) { |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 301 | kfree(ctx->ring_pages); |
Sasha Levin | ddb8c45 | 2013-11-19 17:33:03 -0500 | [diff] [blame] | 302 | ctx->ring_pages = NULL; |
| 303 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 304 | } |
| 305 | |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 306 | static int aio_ring_mmap(struct file *file, struct vm_area_struct *vma) |
| 307 | { |
Pavel Emelyanov | e4a0d3e | 2014-09-18 19:56:17 +0400 | [diff] [blame] | 308 | vma->vm_flags |= VM_DONTEXPAND; |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 309 | vma->vm_ops = &generic_file_vm_ops; |
| 310 | return 0; |
| 311 | } |
| 312 | |
Pavel Emelyanov | e4a0d3e | 2014-09-18 19:56:17 +0400 | [diff] [blame] | 313 | static void aio_ring_remap(struct file *file, struct vm_area_struct *vma) |
| 314 | { |
| 315 | struct mm_struct *mm = vma->vm_mm; |
| 316 | struct kioctx_table *table; |
| 317 | int i; |
| 318 | |
| 319 | spin_lock(&mm->ioctx_lock); |
| 320 | rcu_read_lock(); |
| 321 | table = rcu_dereference(mm->ioctx_table); |
| 322 | for (i = 0; i < table->nr; i++) { |
| 323 | struct kioctx *ctx; |
| 324 | |
| 325 | ctx = table->table[i]; |
| 326 | if (ctx && ctx->aio_ring_file == file) { |
| 327 | ctx->user_id = ctx->mmap_base = vma->vm_start; |
| 328 | break; |
| 329 | } |
| 330 | } |
| 331 | |
| 332 | rcu_read_unlock(); |
| 333 | spin_unlock(&mm->ioctx_lock); |
| 334 | } |
| 335 | |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 336 | static const struct file_operations aio_ring_fops = { |
| 337 | .mmap = aio_ring_mmap, |
Pavel Emelyanov | e4a0d3e | 2014-09-18 19:56:17 +0400 | [diff] [blame] | 338 | .mremap = aio_ring_remap, |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 339 | }; |
| 340 | |
Benjamin LaHaise | 0c45355 | 2013-07-17 09:34:24 -0400 | [diff] [blame] | 341 | #if IS_ENABLED(CONFIG_MIGRATION) |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 342 | static int aio_migratepage(struct address_space *mapping, struct page *new, |
| 343 | struct page *old, enum migrate_mode mode) |
| 344 | { |
Benjamin LaHaise | 5e9ae2e | 2013-09-26 20:34:51 -0400 | [diff] [blame] | 345 | struct kioctx *ctx; |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 346 | unsigned long flags; |
Benjamin LaHaise | fa8a53c | 2014-03-28 10:14:45 -0400 | [diff] [blame] | 347 | pgoff_t idx; |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 348 | int rc; |
| 349 | |
Benjamin LaHaise | 8e321fe | 2013-12-21 17:56:08 -0500 | [diff] [blame] | 350 | rc = 0; |
| 351 | |
Benjamin LaHaise | fa8a53c | 2014-03-28 10:14:45 -0400 | [diff] [blame] | 352 | /* mapping->private_lock here protects against the kioctx teardown. */ |
Benjamin LaHaise | 8e321fe | 2013-12-21 17:56:08 -0500 | [diff] [blame] | 353 | spin_lock(&mapping->private_lock); |
| 354 | ctx = mapping->private_data; |
Benjamin LaHaise | fa8a53c | 2014-03-28 10:14:45 -0400 | [diff] [blame] | 355 | if (!ctx) { |
| 356 | rc = -EINVAL; |
| 357 | goto out; |
| 358 | } |
| 359 | |
| 360 | /* The ring_lock mutex. The prevents aio_read_events() from writing |
| 361 | * to the ring's head, and prevents page migration from mucking in |
| 362 | * a partially initialized kiotx. |
| 363 | */ |
| 364 | if (!mutex_trylock(&ctx->ring_lock)) { |
| 365 | rc = -EAGAIN; |
| 366 | goto out; |
| 367 | } |
| 368 | |
| 369 | idx = old->index; |
| 370 | if (idx < (pgoff_t)ctx->nr_pages) { |
| 371 | /* Make sure the old page hasn't already been changed */ |
| 372 | if (ctx->ring_pages[idx] != old) |
| 373 | rc = -EAGAIN; |
Benjamin LaHaise | 8e321fe | 2013-12-21 17:56:08 -0500 | [diff] [blame] | 374 | } else |
| 375 | rc = -EINVAL; |
Benjamin LaHaise | 8e321fe | 2013-12-21 17:56:08 -0500 | [diff] [blame] | 376 | |
| 377 | if (rc != 0) |
Benjamin LaHaise | fa8a53c | 2014-03-28 10:14:45 -0400 | [diff] [blame] | 378 | goto out_unlock; |
Benjamin LaHaise | 8e321fe | 2013-12-21 17:56:08 -0500 | [diff] [blame] | 379 | |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 380 | /* Writeback must be complete */ |
| 381 | BUG_ON(PageWriteback(old)); |
Benjamin LaHaise | 8e321fe | 2013-12-21 17:56:08 -0500 | [diff] [blame] | 382 | get_page(new); |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 383 | |
Benjamin LaHaise | 8e321fe | 2013-12-21 17:56:08 -0500 | [diff] [blame] | 384 | rc = migrate_page_move_mapping(mapping, new, old, NULL, mode, 1); |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 385 | if (rc != MIGRATEPAGE_SUCCESS) { |
Benjamin LaHaise | 8e321fe | 2013-12-21 17:56:08 -0500 | [diff] [blame] | 386 | put_page(new); |
Benjamin LaHaise | fa8a53c | 2014-03-28 10:14:45 -0400 | [diff] [blame] | 387 | goto out_unlock; |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 388 | } |
| 389 | |
Benjamin LaHaise | fa8a53c | 2014-03-28 10:14:45 -0400 | [diff] [blame] | 390 | /* Take completion_lock to prevent other writes to the ring buffer |
| 391 | * while the old page is copied to the new. This prevents new |
| 392 | * events from being lost. |
Benjamin LaHaise | 5e9ae2e | 2013-09-26 20:34:51 -0400 | [diff] [blame] | 393 | */ |
Benjamin LaHaise | fa8a53c | 2014-03-28 10:14:45 -0400 | [diff] [blame] | 394 | spin_lock_irqsave(&ctx->completion_lock, flags); |
| 395 | migrate_page_copy(new, old); |
| 396 | BUG_ON(ctx->ring_pages[idx] != old); |
| 397 | ctx->ring_pages[idx] = new; |
| 398 | spin_unlock_irqrestore(&ctx->completion_lock, flags); |
| 399 | |
| 400 | /* The old page is no longer accessible. */ |
| 401 | put_page(old); |
| 402 | |
| 403 | out_unlock: |
| 404 | mutex_unlock(&ctx->ring_lock); |
| 405 | out: |
Benjamin LaHaise | 5e9ae2e | 2013-09-26 20:34:51 -0400 | [diff] [blame] | 406 | spin_unlock(&mapping->private_lock); |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 407 | return rc; |
| 408 | } |
Benjamin LaHaise | 0c45355 | 2013-07-17 09:34:24 -0400 | [diff] [blame] | 409 | #endif |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 410 | |
| 411 | static const struct address_space_operations aio_ctx_aops = { |
Gu Zheng | 835f252 | 2014-11-06 17:46:21 +0800 | [diff] [blame] | 412 | .set_page_dirty = __set_page_dirty_no_writeback, |
Benjamin LaHaise | 0c45355 | 2013-07-17 09:34:24 -0400 | [diff] [blame] | 413 | #if IS_ENABLED(CONFIG_MIGRATION) |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 414 | .migratepage = aio_migratepage, |
Benjamin LaHaise | 0c45355 | 2013-07-17 09:34:24 -0400 | [diff] [blame] | 415 | #endif |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 416 | }; |
| 417 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 418 | static int aio_setup_ring(struct kioctx *ctx) |
| 419 | { |
| 420 | struct aio_ring *ring; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 421 | unsigned nr_events = ctx->max_reqs; |
Zach Brown | 41003a7 | 2013-05-07 16:18:25 -0700 | [diff] [blame] | 422 | struct mm_struct *mm = current->mm; |
Linus Torvalds | 3dc9acb | 2013-12-20 05:11:12 +0900 | [diff] [blame] | 423 | unsigned long size, unused; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 424 | int nr_pages; |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 425 | int i; |
| 426 | struct file *file; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | |
| 428 | /* Compensate for the ring buffer's head/tail overlap entry */ |
| 429 | nr_events += 2; /* 1 is required, 2 for good luck */ |
| 430 | |
| 431 | size = sizeof(struct aio_ring); |
| 432 | size += sizeof(struct io_event) * nr_events; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 434 | nr_pages = PFN_UP(size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | if (nr_pages < 0) |
| 436 | return -EINVAL; |
| 437 | |
Benjamin LaHaise | 71ad749 | 2013-09-17 10:18:25 -0400 | [diff] [blame] | 438 | file = aio_private_file(ctx, nr_pages); |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 439 | if (IS_ERR(file)) { |
| 440 | ctx->aio_ring_file = NULL; |
Benjamin LaHaise | fa8a53c | 2014-03-28 10:14:45 -0400 | [diff] [blame] | 441 | return -ENOMEM; |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 442 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 443 | |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 444 | ctx->aio_ring_file = file; |
| 445 | nr_events = (PAGE_SIZE * nr_pages - sizeof(struct aio_ring)) |
| 446 | / sizeof(struct io_event); |
| 447 | |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 448 | ctx->ring_pages = ctx->internal_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | if (nr_pages > AIO_RING_PAGES) { |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 450 | ctx->ring_pages = kcalloc(nr_pages, sizeof(struct page *), |
| 451 | GFP_KERNEL); |
Gu Zheng | d1b9432 | 2013-12-04 18:19:06 +0800 | [diff] [blame] | 452 | if (!ctx->ring_pages) { |
| 453 | put_aio_ring_file(ctx); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | return -ENOMEM; |
Gu Zheng | d1b9432 | 2013-12-04 18:19:06 +0800 | [diff] [blame] | 455 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 456 | } |
| 457 | |
Linus Torvalds | 3dc9acb | 2013-12-20 05:11:12 +0900 | [diff] [blame] | 458 | for (i = 0; i < nr_pages; i++) { |
| 459 | struct page *page; |
| 460 | page = find_or_create_page(file->f_inode->i_mapping, |
| 461 | i, GFP_HIGHUSER | __GFP_ZERO); |
| 462 | if (!page) |
| 463 | break; |
| 464 | pr_debug("pid(%d) page[%d]->count=%d\n", |
| 465 | current->pid, i, page_count(page)); |
| 466 | SetPageUptodate(page); |
Linus Torvalds | 3dc9acb | 2013-12-20 05:11:12 +0900 | [diff] [blame] | 467 | unlock_page(page); |
| 468 | |
| 469 | ctx->ring_pages[i] = page; |
| 470 | } |
| 471 | ctx->nr_pages = i; |
| 472 | |
| 473 | if (unlikely(i != nr_pages)) { |
| 474 | aio_free_ring(ctx); |
Benjamin LaHaise | fa8a53c | 2014-03-28 10:14:45 -0400 | [diff] [blame] | 475 | return -ENOMEM; |
Linus Torvalds | 3dc9acb | 2013-12-20 05:11:12 +0900 | [diff] [blame] | 476 | } |
| 477 | |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 478 | ctx->mmap_size = nr_pages * PAGE_SIZE; |
| 479 | pr_debug("attempting mmap of %lu bytes\n", ctx->mmap_size); |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 480 | |
Zach Brown | 41003a7 | 2013-05-07 16:18:25 -0700 | [diff] [blame] | 481 | down_write(&mm->mmap_sem); |
Gu Zheng | 36bc08c | 2013-07-16 17:56:16 +0800 | [diff] [blame] | 482 | ctx->mmap_base = do_mmap_pgoff(ctx->aio_ring_file, 0, ctx->mmap_size, |
| 483 | PROT_READ | PROT_WRITE, |
Linus Torvalds | 3dc9acb | 2013-12-20 05:11:12 +0900 | [diff] [blame] | 484 | MAP_SHARED, 0, &unused); |
| 485 | up_write(&mm->mmap_sem); |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 486 | if (IS_ERR((void *)ctx->mmap_base)) { |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 487 | ctx->mmap_size = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 488 | aio_free_ring(ctx); |
Benjamin LaHaise | fa8a53c | 2014-03-28 10:14:45 -0400 | [diff] [blame] | 489 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 490 | } |
| 491 | |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 492 | pr_debug("mmap address: 0x%08lx\n", ctx->mmap_base); |
Benjamin LaHaise | d6c355c | 2013-09-09 11:57:59 -0400 | [diff] [blame] | 493 | |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 494 | ctx->user_id = ctx->mmap_base; |
| 495 | ctx->nr_events = nr_events; /* trusted copy */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 497 | ring = kmap_atomic(ctx->ring_pages[0]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | ring->nr = nr_events; /* user copy */ |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 499 | ring->id = ~0U; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | ring->head = ring->tail = 0; |
| 501 | ring->magic = AIO_RING_MAGIC; |
| 502 | ring->compat_features = AIO_RING_COMPAT_FEATURES; |
| 503 | ring->incompat_features = AIO_RING_INCOMPAT_FEATURES; |
| 504 | ring->header_length = sizeof(struct aio_ring); |
Cong Wang | e8e3c3d | 2011-11-25 23:14:27 +0800 | [diff] [blame] | 505 | kunmap_atomic(ring); |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 506 | flush_dcache_page(ctx->ring_pages[0]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 507 | |
| 508 | return 0; |
| 509 | } |
| 510 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 511 | #define AIO_EVENTS_PER_PAGE (PAGE_SIZE / sizeof(struct io_event)) |
| 512 | #define AIO_EVENTS_FIRST_PAGE ((PAGE_SIZE - sizeof(struct aio_ring)) / sizeof(struct io_event)) |
| 513 | #define AIO_EVENTS_OFFSET (AIO_EVENTS_PER_PAGE - AIO_EVENTS_FIRST_PAGE) |
| 514 | |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 515 | void kiocb_set_cancel_fn(struct kiocb *iocb, kiocb_cancel_fn *cancel) |
Kent Overstreet | 0460fef | 2013-05-07 16:18:49 -0700 | [diff] [blame] | 516 | { |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 517 | struct aio_kiocb *req = container_of(iocb, struct aio_kiocb, common); |
Kent Overstreet | 0460fef | 2013-05-07 16:18:49 -0700 | [diff] [blame] | 518 | struct kioctx *ctx = req->ki_ctx; |
| 519 | unsigned long flags; |
| 520 | |
| 521 | spin_lock_irqsave(&ctx->ctx_lock, flags); |
| 522 | |
| 523 | if (!req->ki_list.next) |
| 524 | list_add(&req->ki_list, &ctx->active_reqs); |
| 525 | |
| 526 | req->ki_cancel = cancel; |
| 527 | |
| 528 | spin_unlock_irqrestore(&ctx->ctx_lock, flags); |
| 529 | } |
| 530 | EXPORT_SYMBOL(kiocb_set_cancel_fn); |
| 531 | |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 532 | static int kiocb_cancel(struct aio_kiocb *kiocb) |
Kent Overstreet | 906b973 | 2013-05-07 16:18:31 -0700 | [diff] [blame] | 533 | { |
Kent Overstreet | 0460fef | 2013-05-07 16:18:49 -0700 | [diff] [blame] | 534 | kiocb_cancel_fn *old, *cancel; |
Kent Overstreet | 906b973 | 2013-05-07 16:18:31 -0700 | [diff] [blame] | 535 | |
Kent Overstreet | 0460fef | 2013-05-07 16:18:49 -0700 | [diff] [blame] | 536 | /* |
| 537 | * Don't want to set kiocb->ki_cancel = KIOCB_CANCELLED unless it |
| 538 | * actually has a cancel function, hence the cmpxchg() |
| 539 | */ |
Kent Overstreet | 906b973 | 2013-05-07 16:18:31 -0700 | [diff] [blame] | 540 | |
Kent Overstreet | 0460fef | 2013-05-07 16:18:49 -0700 | [diff] [blame] | 541 | cancel = ACCESS_ONCE(kiocb->ki_cancel); |
| 542 | do { |
| 543 | if (!cancel || cancel == KIOCB_CANCELLED) |
Kent Overstreet | 57282d8 | 2013-05-13 13:42:52 -0700 | [diff] [blame] | 544 | return -EINVAL; |
Kent Overstreet | 906b973 | 2013-05-07 16:18:31 -0700 | [diff] [blame] | 545 | |
Kent Overstreet | 0460fef | 2013-05-07 16:18:49 -0700 | [diff] [blame] | 546 | old = cancel; |
| 547 | cancel = cmpxchg(&kiocb->ki_cancel, old, KIOCB_CANCELLED); |
| 548 | } while (cancel != old); |
| 549 | |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 550 | return cancel(&kiocb->common); |
Kent Overstreet | 906b973 | 2013-05-07 16:18:31 -0700 | [diff] [blame] | 551 | } |
| 552 | |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 553 | static void free_ioctx(struct work_struct *work) |
Kent Overstreet | 36f5588 | 2013-05-07 16:18:41 -0700 | [diff] [blame] | 554 | { |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 555 | struct kioctx *ctx = container_of(work, struct kioctx, free_work); |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 556 | |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 557 | pr_debug("freeing %p\n", ctx); |
| 558 | |
| 559 | aio_free_ring(ctx); |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 560 | free_percpu(ctx->cpu); |
Tejun Heo | 9a1049d | 2014-06-28 08:10:14 -0400 | [diff] [blame] | 561 | percpu_ref_exit(&ctx->reqs); |
| 562 | percpu_ref_exit(&ctx->users); |
Kent Overstreet | 36f5588 | 2013-05-07 16:18:41 -0700 | [diff] [blame] | 563 | kmem_cache_free(kioctx_cachep, ctx); |
| 564 | } |
| 565 | |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 566 | static void free_ioctx_reqs(struct percpu_ref *ref) |
| 567 | { |
| 568 | struct kioctx *ctx = container_of(ref, struct kioctx, reqs); |
| 569 | |
Anatol Pomozov | e02ba72 | 2014-04-15 11:31:33 -0700 | [diff] [blame] | 570 | /* At this point we know that there are no any in-flight requests */ |
| 571 | if (ctx->requests_done) |
| 572 | complete(ctx->requests_done); |
| 573 | |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 574 | INIT_WORK(&ctx->free_work, free_ioctx); |
| 575 | schedule_work(&ctx->free_work); |
| 576 | } |
| 577 | |
Kent Overstreet | 36f5588 | 2013-05-07 16:18:41 -0700 | [diff] [blame] | 578 | /* |
| 579 | * When this function runs, the kioctx has been removed from the "hash table" |
| 580 | * and ctx->users has dropped to 0, so we know no more kiocbs can be submitted - |
| 581 | * now it's safe to cancel any that need to be. |
| 582 | */ |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 583 | static void free_ioctx_users(struct percpu_ref *ref) |
Kent Overstreet | 36f5588 | 2013-05-07 16:18:41 -0700 | [diff] [blame] | 584 | { |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 585 | struct kioctx *ctx = container_of(ref, struct kioctx, users); |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 586 | struct aio_kiocb *req; |
Kent Overstreet | 36f5588 | 2013-05-07 16:18:41 -0700 | [diff] [blame] | 587 | |
| 588 | spin_lock_irq(&ctx->ctx_lock); |
| 589 | |
| 590 | while (!list_empty(&ctx->active_reqs)) { |
| 591 | req = list_first_entry(&ctx->active_reqs, |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 592 | struct aio_kiocb, ki_list); |
Kent Overstreet | 36f5588 | 2013-05-07 16:18:41 -0700 | [diff] [blame] | 593 | |
| 594 | list_del_init(&req->ki_list); |
Fabian Frederick | d52a8f9 | 2014-04-22 07:26:58 +0200 | [diff] [blame] | 595 | kiocb_cancel(req); |
Kent Overstreet | 36f5588 | 2013-05-07 16:18:41 -0700 | [diff] [blame] | 596 | } |
| 597 | |
| 598 | spin_unlock_irq(&ctx->ctx_lock); |
| 599 | |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 600 | percpu_ref_kill(&ctx->reqs); |
| 601 | percpu_ref_put(&ctx->reqs); |
Kent Overstreet | 36f5588 | 2013-05-07 16:18:41 -0700 | [diff] [blame] | 602 | } |
| 603 | |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 604 | static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm) |
| 605 | { |
| 606 | unsigned i, new_nr; |
| 607 | struct kioctx_table *table, *old; |
| 608 | struct aio_ring *ring; |
| 609 | |
| 610 | spin_lock(&mm->ioctx_lock); |
Oleg Nesterov | 855ef0d | 2014-04-30 16:16:36 +0200 | [diff] [blame] | 611 | table = rcu_dereference_raw(mm->ioctx_table); |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 612 | |
| 613 | while (1) { |
| 614 | if (table) |
| 615 | for (i = 0; i < table->nr; i++) |
| 616 | if (!table->table[i]) { |
| 617 | ctx->id = i; |
| 618 | table->table[i] = ctx; |
| 619 | spin_unlock(&mm->ioctx_lock); |
| 620 | |
Benjamin LaHaise | fa8a53c | 2014-03-28 10:14:45 -0400 | [diff] [blame] | 621 | /* While kioctx setup is in progress, |
| 622 | * we are protected from page migration |
| 623 | * changes ring_pages by ->ring_lock. |
| 624 | */ |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 625 | ring = kmap_atomic(ctx->ring_pages[0]); |
| 626 | ring->id = ctx->id; |
| 627 | kunmap_atomic(ring); |
| 628 | return 0; |
| 629 | } |
| 630 | |
| 631 | new_nr = (table ? table->nr : 1) * 4; |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 632 | spin_unlock(&mm->ioctx_lock); |
| 633 | |
| 634 | table = kzalloc(sizeof(*table) + sizeof(struct kioctx *) * |
| 635 | new_nr, GFP_KERNEL); |
| 636 | if (!table) |
| 637 | return -ENOMEM; |
| 638 | |
| 639 | table->nr = new_nr; |
| 640 | |
| 641 | spin_lock(&mm->ioctx_lock); |
Oleg Nesterov | 855ef0d | 2014-04-30 16:16:36 +0200 | [diff] [blame] | 642 | old = rcu_dereference_raw(mm->ioctx_table); |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 643 | |
| 644 | if (!old) { |
| 645 | rcu_assign_pointer(mm->ioctx_table, table); |
| 646 | } else if (table->nr > old->nr) { |
| 647 | memcpy(table->table, old->table, |
| 648 | old->nr * sizeof(struct kioctx *)); |
| 649 | |
| 650 | rcu_assign_pointer(mm->ioctx_table, table); |
| 651 | kfree_rcu(old, rcu); |
| 652 | } else { |
| 653 | kfree(table); |
| 654 | table = old; |
| 655 | } |
| 656 | } |
| 657 | } |
| 658 | |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 659 | static void aio_nr_sub(unsigned nr) |
| 660 | { |
| 661 | spin_lock(&aio_nr_lock); |
| 662 | if (WARN_ON(aio_nr - nr > aio_nr)) |
| 663 | aio_nr = 0; |
| 664 | else |
| 665 | aio_nr -= nr; |
| 666 | spin_unlock(&aio_nr_lock); |
| 667 | } |
| 668 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | /* ioctx_alloc |
| 670 | * Allocates and initializes an ioctx. Returns an ERR_PTR if it failed. |
| 671 | */ |
| 672 | static struct kioctx *ioctx_alloc(unsigned nr_events) |
| 673 | { |
Zach Brown | 41003a7 | 2013-05-07 16:18:25 -0700 | [diff] [blame] | 674 | struct mm_struct *mm = current->mm; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 675 | struct kioctx *ctx; |
Al Viro | e23754f | 2012-03-06 14:33:22 -0500 | [diff] [blame] | 676 | int err = -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 677 | |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 678 | /* |
| 679 | * We keep track of the number of available ringbuffer slots, to prevent |
| 680 | * overflow (reqs_available), and we also use percpu counters for this. |
| 681 | * |
| 682 | * So since up to half the slots might be on other cpu's percpu counters |
| 683 | * and unavailable, double nr_events so userspace sees what they |
| 684 | * expected: additionally, we move req_batch slots to/from percpu |
| 685 | * counters at a time, so make sure that isn't 0: |
| 686 | */ |
| 687 | nr_events = max(nr_events, num_possible_cpus() * 4); |
| 688 | nr_events *= 2; |
| 689 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 690 | /* Prevent overflows */ |
Al Viro | 08397ac | 2015-03-31 11:43:52 -0400 | [diff] [blame] | 691 | if (nr_events > (0x10000000U / sizeof(struct io_event))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 692 | pr_debug("ENOMEM: nr_events too high\n"); |
| 693 | return ERR_PTR(-EINVAL); |
| 694 | } |
| 695 | |
Benjamin LaHaise | 4cd81c3 | 2013-07-30 12:06:37 -0400 | [diff] [blame] | 696 | if (!nr_events || (unsigned long)nr_events > (aio_max_nr * 2UL)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 697 | return ERR_PTR(-EAGAIN); |
| 698 | |
Robert P. J. Day | c376222 | 2007-02-10 01:45:03 -0800 | [diff] [blame] | 699 | ctx = kmem_cache_zalloc(kioctx_cachep, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 700 | if (!ctx) |
| 701 | return ERR_PTR(-ENOMEM); |
| 702 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 703 | ctx->max_reqs = nr_events; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 704 | |
Benjamin LaHaise | fa8a53c | 2014-03-28 10:14:45 -0400 | [diff] [blame] | 705 | spin_lock_init(&ctx->ctx_lock); |
| 706 | spin_lock_init(&ctx->completion_lock); |
| 707 | mutex_init(&ctx->ring_lock); |
| 708 | /* Protect against page migration throughout kiotx setup by keeping |
| 709 | * the ring_lock mutex held until setup is complete. */ |
| 710 | mutex_lock(&ctx->ring_lock); |
| 711 | init_waitqueue_head(&ctx->wait); |
| 712 | |
| 713 | INIT_LIST_HEAD(&ctx->active_reqs); |
| 714 | |
Tejun Heo | 2aad2a8 | 2014-09-24 13:31:50 -0400 | [diff] [blame] | 715 | if (percpu_ref_init(&ctx->users, free_ioctx_users, 0, GFP_KERNEL)) |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 716 | goto err; |
| 717 | |
Tejun Heo | 2aad2a8 | 2014-09-24 13:31:50 -0400 | [diff] [blame] | 718 | if (percpu_ref_init(&ctx->reqs, free_ioctx_reqs, 0, GFP_KERNEL)) |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 719 | goto err; |
Kent Overstreet | 723be6e | 2013-05-28 15:14:48 -0700 | [diff] [blame] | 720 | |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 721 | ctx->cpu = alloc_percpu(struct kioctx_cpu); |
| 722 | if (!ctx->cpu) |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 723 | goto err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 724 | |
Benjamin LaHaise | fa8a53c | 2014-03-28 10:14:45 -0400 | [diff] [blame] | 725 | err = aio_setup_ring(ctx); |
| 726 | if (err < 0) |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 727 | goto err; |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 728 | |
Kent Overstreet | 34e83fc | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 729 | atomic_set(&ctx->reqs_available, ctx->nr_events - 1); |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 730 | ctx->req_batch = (ctx->nr_events - 1) / (num_possible_cpus() * 4); |
Benjamin LaHaise | 6878ea7 | 2013-07-31 10:34:18 -0400 | [diff] [blame] | 731 | if (ctx->req_batch < 1) |
| 732 | ctx->req_batch = 1; |
Kent Overstreet | 34e83fc | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 733 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 734 | /* limit the number of system wide aios */ |
Al Viro | 9fa1cb3 | 2012-03-10 23:14:05 -0500 | [diff] [blame] | 735 | spin_lock(&aio_nr_lock); |
Benjamin LaHaise | 4cd81c3 | 2013-07-30 12:06:37 -0400 | [diff] [blame] | 736 | if (aio_nr + nr_events > (aio_max_nr * 2UL) || |
Al Viro | 2dd542b | 2012-03-10 23:10:35 -0500 | [diff] [blame] | 737 | aio_nr + nr_events < aio_nr) { |
Al Viro | 9fa1cb3 | 2012-03-10 23:14:05 -0500 | [diff] [blame] | 738 | spin_unlock(&aio_nr_lock); |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 739 | err = -EAGAIN; |
Gu Zheng | d1b9432 | 2013-12-04 18:19:06 +0800 | [diff] [blame] | 740 | goto err_ctx; |
Al Viro | 2dd542b | 2012-03-10 23:10:35 -0500 | [diff] [blame] | 741 | } |
| 742 | aio_nr += ctx->max_reqs; |
Al Viro | 9fa1cb3 | 2012-03-10 23:14:05 -0500 | [diff] [blame] | 743 | spin_unlock(&aio_nr_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 744 | |
Benjamin LaHaise | 1881686 | 2013-12-21 15:49:28 -0500 | [diff] [blame] | 745 | percpu_ref_get(&ctx->users); /* io_setup() will drop this ref */ |
| 746 | percpu_ref_get(&ctx->reqs); /* free_ioctx_users() will drop this */ |
Kent Overstreet | 723be6e | 2013-05-28 15:14:48 -0700 | [diff] [blame] | 747 | |
Benjamin LaHaise | da90382 | 2013-08-05 13:21:43 -0400 | [diff] [blame] | 748 | err = ioctx_add_table(ctx, mm); |
| 749 | if (err) |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 750 | goto err_cleanup; |
Benjamin LaHaise | da90382 | 2013-08-05 13:21:43 -0400 | [diff] [blame] | 751 | |
Benjamin LaHaise | fa8a53c | 2014-03-28 10:14:45 -0400 | [diff] [blame] | 752 | /* Release the ring_lock mutex now that all setup is complete. */ |
| 753 | mutex_unlock(&ctx->ring_lock); |
| 754 | |
Kent Overstreet | caf4167 | 2013-05-07 16:18:35 -0700 | [diff] [blame] | 755 | pr_debug("allocated ioctx %p[%ld]: mm=%p mask=0x%x\n", |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 756 | ctx, ctx->user_id, mm, ctx->nr_events); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 757 | return ctx; |
| 758 | |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 759 | err_cleanup: |
| 760 | aio_nr_sub(ctx->max_reqs); |
Gu Zheng | d1b9432 | 2013-12-04 18:19:06 +0800 | [diff] [blame] | 761 | err_ctx: |
| 762 | aio_free_ring(ctx); |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 763 | err: |
Benjamin LaHaise | fa8a53c | 2014-03-28 10:14:45 -0400 | [diff] [blame] | 764 | mutex_unlock(&ctx->ring_lock); |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 765 | free_percpu(ctx->cpu); |
Tejun Heo | 9a1049d | 2014-06-28 08:10:14 -0400 | [diff] [blame] | 766 | percpu_ref_exit(&ctx->reqs); |
| 767 | percpu_ref_exit(&ctx->users); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | kmem_cache_free(kioctx_cachep, ctx); |
Kent Overstreet | caf4167 | 2013-05-07 16:18:35 -0700 | [diff] [blame] | 769 | pr_debug("error allocating ioctx %d\n", err); |
Al Viro | e23754f | 2012-03-06 14:33:22 -0500 | [diff] [blame] | 770 | return ERR_PTR(err); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 771 | } |
| 772 | |
Kent Overstreet | 36f5588 | 2013-05-07 16:18:41 -0700 | [diff] [blame] | 773 | /* kill_ioctx |
| 774 | * Cancels all outstanding aio requests on an aio context. Used |
| 775 | * when the processes owning a context have all exited to encourage |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 776 | * the rapid destruction of the kioctx. |
| 777 | */ |
Benjamin LaHaise | fb2d448 | 2014-04-29 12:45:17 -0400 | [diff] [blame] | 778 | static int kill_ioctx(struct mm_struct *mm, struct kioctx *ctx, |
Anatol Pomozov | e02ba72 | 2014-04-15 11:31:33 -0700 | [diff] [blame] | 779 | struct completion *requests_done) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 780 | { |
Benjamin LaHaise | fa88b6f | 2014-04-29 12:55:48 -0400 | [diff] [blame] | 781 | struct kioctx_table *table; |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 782 | |
Benjamin LaHaise | fa88b6f | 2014-04-29 12:55:48 -0400 | [diff] [blame] | 783 | if (atomic_xchg(&ctx->dead, 1)) |
| 784 | return -EINVAL; |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 785 | |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 786 | |
Benjamin LaHaise | fa88b6f | 2014-04-29 12:55:48 -0400 | [diff] [blame] | 787 | spin_lock(&mm->ioctx_lock); |
Oleg Nesterov | 855ef0d | 2014-04-30 16:16:36 +0200 | [diff] [blame] | 788 | table = rcu_dereference_raw(mm->ioctx_table); |
Benjamin LaHaise | fa88b6f | 2014-04-29 12:55:48 -0400 | [diff] [blame] | 789 | WARN_ON(ctx != table->table[ctx->id]); |
| 790 | table->table[ctx->id] = NULL; |
Benjamin LaHaise | fa88b6f | 2014-04-29 12:55:48 -0400 | [diff] [blame] | 791 | spin_unlock(&mm->ioctx_lock); |
Kent Overstreet | 4fcc712 | 2013-06-12 14:04:59 -0700 | [diff] [blame] | 792 | |
Benjamin LaHaise | fa88b6f | 2014-04-29 12:55:48 -0400 | [diff] [blame] | 793 | /* percpu_ref_kill() will do the necessary call_rcu() */ |
| 794 | wake_up_all(&ctx->wait); |
Kent Overstreet | 4fcc712 | 2013-06-12 14:04:59 -0700 | [diff] [blame] | 795 | |
Benjamin LaHaise | fa88b6f | 2014-04-29 12:55:48 -0400 | [diff] [blame] | 796 | /* |
| 797 | * It'd be more correct to do this in free_ioctx(), after all |
| 798 | * the outstanding kiocbs have finished - but by then io_destroy |
| 799 | * has already returned, so io_setup() could potentially return |
| 800 | * -EAGAIN with no ioctxs actually in use (as far as userspace |
| 801 | * could tell). |
| 802 | */ |
| 803 | aio_nr_sub(ctx->max_reqs); |
Benjamin LaHaise | fb2d448 | 2014-04-29 12:45:17 -0400 | [diff] [blame] | 804 | |
Benjamin LaHaise | fa88b6f | 2014-04-29 12:55:48 -0400 | [diff] [blame] | 805 | if (ctx->mmap_size) |
| 806 | vm_munmap(ctx->mmap_base, ctx->mmap_size); |
| 807 | |
| 808 | ctx->requests_done = requests_done; |
| 809 | percpu_ref_kill(&ctx->users); |
| 810 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 811 | } |
| 812 | |
Kent Overstreet | 36f5588 | 2013-05-07 16:18:41 -0700 | [diff] [blame] | 813 | /* |
| 814 | * exit_aio: called when the last user of mm goes away. At this point, there is |
| 815 | * no way for any new requests to be submited or any of the io_* syscalls to be |
| 816 | * called on the context. |
| 817 | * |
| 818 | * There may be outstanding kiocbs, but free_ioctx() will explicitly wait on |
| 819 | * them. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 820 | */ |
Harvey Harrison | fc9b52c | 2008-02-08 04:19:52 -0800 | [diff] [blame] | 821 | void exit_aio(struct mm_struct *mm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 822 | { |
Oleg Nesterov | 4b70ac5 | 2014-04-30 19:02:48 +0200 | [diff] [blame] | 823 | struct kioctx_table *table = rcu_dereference_raw(mm->ioctx_table); |
| 824 | int i; |
Jens Axboe | abf137d | 2008-12-09 08:11:22 +0100 | [diff] [blame] | 825 | |
Oleg Nesterov | 4b70ac5 | 2014-04-30 19:02:48 +0200 | [diff] [blame] | 826 | if (!table) |
| 827 | return; |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 828 | |
Oleg Nesterov | 4b70ac5 | 2014-04-30 19:02:48 +0200 | [diff] [blame] | 829 | for (i = 0; i < table->nr; ++i) { |
| 830 | struct kioctx *ctx = table->table[i]; |
Gu Zheng | 6098b45 | 2014-09-03 17:45:44 +0800 | [diff] [blame] | 831 | struct completion requests_done = |
| 832 | COMPLETION_INITIALIZER_ONSTACK(requests_done); |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 833 | |
Oleg Nesterov | 4b70ac5 | 2014-04-30 19:02:48 +0200 | [diff] [blame] | 834 | if (!ctx) |
| 835 | continue; |
Al Viro | 936af15 | 2012-04-20 21:49:41 -0400 | [diff] [blame] | 836 | /* |
Oleg Nesterov | 4b70ac5 | 2014-04-30 19:02:48 +0200 | [diff] [blame] | 837 | * We don't need to bother with munmap() here - exit_mmap(mm) |
| 838 | * is coming and it'll unmap everything. And we simply can't, |
| 839 | * this is not necessarily our ->mm. |
| 840 | * Since kill_ioctx() uses non-zero ->mmap_size as indicator |
| 841 | * that it needs to unmap the area, just set it to 0. |
Al Viro | 936af15 | 2012-04-20 21:49:41 -0400 | [diff] [blame] | 842 | */ |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 843 | ctx->mmap_size = 0; |
Gu Zheng | 6098b45 | 2014-09-03 17:45:44 +0800 | [diff] [blame] | 844 | kill_ioctx(mm, ctx, &requests_done); |
Kent Overstreet | 36f5588 | 2013-05-07 16:18:41 -0700 | [diff] [blame] | 845 | |
Gu Zheng | 6098b45 | 2014-09-03 17:45:44 +0800 | [diff] [blame] | 846 | /* Wait until all IO for the context are done. */ |
| 847 | wait_for_completion(&requests_done); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 848 | } |
Oleg Nesterov | 4b70ac5 | 2014-04-30 19:02:48 +0200 | [diff] [blame] | 849 | |
| 850 | RCU_INIT_POINTER(mm->ioctx_table, NULL); |
| 851 | kfree(table); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 852 | } |
| 853 | |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 854 | static void put_reqs_available(struct kioctx *ctx, unsigned nr) |
| 855 | { |
| 856 | struct kioctx_cpu *kcpu; |
Benjamin LaHaise | 263782c | 2014-07-14 12:49:26 -0400 | [diff] [blame] | 857 | unsigned long flags; |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 858 | |
Benjamin LaHaise | 263782c | 2014-07-14 12:49:26 -0400 | [diff] [blame] | 859 | local_irq_save(flags); |
Benjamin LaHaise | be6fb45 | 2014-07-22 09:56:56 -0400 | [diff] [blame] | 860 | kcpu = this_cpu_ptr(ctx->cpu); |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 861 | kcpu->reqs_available += nr; |
Benjamin LaHaise | 263782c | 2014-07-14 12:49:26 -0400 | [diff] [blame] | 862 | |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 863 | while (kcpu->reqs_available >= ctx->req_batch * 2) { |
| 864 | kcpu->reqs_available -= ctx->req_batch; |
| 865 | atomic_add(ctx->req_batch, &ctx->reqs_available); |
| 866 | } |
| 867 | |
Benjamin LaHaise | 263782c | 2014-07-14 12:49:26 -0400 | [diff] [blame] | 868 | local_irq_restore(flags); |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 869 | } |
| 870 | |
| 871 | static bool get_reqs_available(struct kioctx *ctx) |
| 872 | { |
| 873 | struct kioctx_cpu *kcpu; |
| 874 | bool ret = false; |
Benjamin LaHaise | 263782c | 2014-07-14 12:49:26 -0400 | [diff] [blame] | 875 | unsigned long flags; |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 876 | |
Benjamin LaHaise | 263782c | 2014-07-14 12:49:26 -0400 | [diff] [blame] | 877 | local_irq_save(flags); |
Benjamin LaHaise | be6fb45 | 2014-07-22 09:56:56 -0400 | [diff] [blame] | 878 | kcpu = this_cpu_ptr(ctx->cpu); |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 879 | if (!kcpu->reqs_available) { |
| 880 | int old, avail = atomic_read(&ctx->reqs_available); |
| 881 | |
| 882 | do { |
| 883 | if (avail < ctx->req_batch) |
| 884 | goto out; |
| 885 | |
| 886 | old = avail; |
| 887 | avail = atomic_cmpxchg(&ctx->reqs_available, |
| 888 | avail, avail - ctx->req_batch); |
| 889 | } while (avail != old); |
| 890 | |
| 891 | kcpu->reqs_available += ctx->req_batch; |
| 892 | } |
| 893 | |
| 894 | ret = true; |
| 895 | kcpu->reqs_available--; |
| 896 | out: |
Benjamin LaHaise | 263782c | 2014-07-14 12:49:26 -0400 | [diff] [blame] | 897 | local_irq_restore(flags); |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 898 | return ret; |
| 899 | } |
| 900 | |
Benjamin LaHaise | d856f32 | 2014-08-24 13:14:05 -0400 | [diff] [blame] | 901 | /* refill_reqs_available |
| 902 | * Updates the reqs_available reference counts used for tracking the |
| 903 | * number of free slots in the completion ring. This can be called |
| 904 | * from aio_complete() (to optimistically update reqs_available) or |
| 905 | * from aio_get_req() (the we're out of events case). It must be |
| 906 | * called holding ctx->completion_lock. |
| 907 | */ |
| 908 | static void refill_reqs_available(struct kioctx *ctx, unsigned head, |
| 909 | unsigned tail) |
| 910 | { |
| 911 | unsigned events_in_ring, completed; |
| 912 | |
| 913 | /* Clamp head since userland can write to it. */ |
| 914 | head %= ctx->nr_events; |
| 915 | if (head <= tail) |
| 916 | events_in_ring = tail - head; |
| 917 | else |
| 918 | events_in_ring = ctx->nr_events - (head - tail); |
| 919 | |
| 920 | completed = ctx->completed_events; |
| 921 | if (events_in_ring < completed) |
| 922 | completed -= events_in_ring; |
| 923 | else |
| 924 | completed = 0; |
| 925 | |
| 926 | if (!completed) |
| 927 | return; |
| 928 | |
| 929 | ctx->completed_events -= completed; |
| 930 | put_reqs_available(ctx, completed); |
| 931 | } |
| 932 | |
| 933 | /* user_refill_reqs_available |
| 934 | * Called to refill reqs_available when aio_get_req() encounters an |
| 935 | * out of space in the completion ring. |
| 936 | */ |
| 937 | static void user_refill_reqs_available(struct kioctx *ctx) |
| 938 | { |
| 939 | spin_lock_irq(&ctx->completion_lock); |
| 940 | if (ctx->completed_events) { |
| 941 | struct aio_ring *ring; |
| 942 | unsigned head; |
| 943 | |
| 944 | /* Access of ring->head may race with aio_read_events_ring() |
| 945 | * here, but that's okay since whether we read the old version |
| 946 | * or the new version, and either will be valid. The important |
| 947 | * part is that head cannot pass tail since we prevent |
| 948 | * aio_complete() from updating tail by holding |
| 949 | * ctx->completion_lock. Even if head is invalid, the check |
| 950 | * against ctx->completed_events below will make sure we do the |
| 951 | * safe/right thing. |
| 952 | */ |
| 953 | ring = kmap_atomic(ctx->ring_pages[0]); |
| 954 | head = ring->head; |
| 955 | kunmap_atomic(ring); |
| 956 | |
| 957 | refill_reqs_available(ctx, head, ctx->tail); |
| 958 | } |
| 959 | |
| 960 | spin_unlock_irq(&ctx->completion_lock); |
| 961 | } |
| 962 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 963 | /* aio_get_req |
Kent Overstreet | 57282d8 | 2013-05-13 13:42:52 -0700 | [diff] [blame] | 964 | * Allocate a slot for an aio request. |
| 965 | * Returns NULL if no requests are free. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 966 | */ |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 967 | static inline struct aio_kiocb *aio_get_req(struct kioctx *ctx) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 968 | { |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 969 | struct aio_kiocb *req; |
Kent Overstreet | a1c8eae | 2013-05-07 16:18:53 -0700 | [diff] [blame] | 970 | |
Benjamin LaHaise | d856f32 | 2014-08-24 13:14:05 -0400 | [diff] [blame] | 971 | if (!get_reqs_available(ctx)) { |
| 972 | user_refill_reqs_available(ctx); |
| 973 | if (!get_reqs_available(ctx)) |
| 974 | return NULL; |
| 975 | } |
Kent Overstreet | a1c8eae | 2013-05-07 16:18:53 -0700 | [diff] [blame] | 976 | |
Kent Overstreet | 0460fef | 2013-05-07 16:18:49 -0700 | [diff] [blame] | 977 | req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL|__GFP_ZERO); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 978 | if (unlikely(!req)) |
Kent Overstreet | a1c8eae | 2013-05-07 16:18:53 -0700 | [diff] [blame] | 979 | goto out_put; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 980 | |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 981 | percpu_ref_get(&ctx->reqs); |
| 982 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 983 | req->ki_ctx = ctx; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 984 | return req; |
Kent Overstreet | a1c8eae | 2013-05-07 16:18:53 -0700 | [diff] [blame] | 985 | out_put: |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 986 | put_reqs_available(ctx, 1); |
Kent Overstreet | a1c8eae | 2013-05-07 16:18:53 -0700 | [diff] [blame] | 987 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 988 | } |
| 989 | |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 990 | static void kiocb_free(struct aio_kiocb *req) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 991 | { |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 992 | if (req->common.ki_filp) |
| 993 | fput(req->common.ki_filp); |
Davide Libenzi | 1338901 | 2009-06-30 11:41:11 -0700 | [diff] [blame] | 994 | if (req->ki_eventfd != NULL) |
| 995 | eventfd_ctx_put(req->ki_eventfd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 996 | kmem_cache_free(kiocb_cachep, req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 997 | } |
| 998 | |
Adrian Bunk | d5470b5 | 2008-04-29 00:58:57 -0700 | [diff] [blame] | 999 | static struct kioctx *lookup_ioctx(unsigned long ctx_id) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1000 | { |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 1001 | struct aio_ring __user *ring = (void __user *)ctx_id; |
Jens Axboe | abf137d | 2008-12-09 08:11:22 +0100 | [diff] [blame] | 1002 | struct mm_struct *mm = current->mm; |
Jeff Moyer | 65c2449 | 2009-03-18 17:04:21 -0700 | [diff] [blame] | 1003 | struct kioctx *ctx, *ret = NULL; |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 1004 | struct kioctx_table *table; |
| 1005 | unsigned id; |
| 1006 | |
| 1007 | if (get_user(id, &ring->id)) |
| 1008 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1009 | |
Jens Axboe | abf137d | 2008-12-09 08:11:22 +0100 | [diff] [blame] | 1010 | rcu_read_lock(); |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 1011 | table = rcu_dereference(mm->ioctx_table); |
Jens Axboe | abf137d | 2008-12-09 08:11:22 +0100 | [diff] [blame] | 1012 | |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 1013 | if (!table || id >= table->nr) |
| 1014 | goto out; |
| 1015 | |
| 1016 | ctx = table->table[id]; |
Benjamin LaHaise | f30d704 | 2013-08-07 18:23:48 -0400 | [diff] [blame] | 1017 | if (ctx && ctx->user_id == ctx_id) { |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 1018 | percpu_ref_get(&ctx->users); |
| 1019 | ret = ctx; |
Jens Axboe | abf137d | 2008-12-09 08:11:22 +0100 | [diff] [blame] | 1020 | } |
Benjamin LaHaise | db446a0 | 2013-07-30 12:54:40 -0400 | [diff] [blame] | 1021 | out: |
Jens Axboe | abf137d | 2008-12-09 08:11:22 +0100 | [diff] [blame] | 1022 | rcu_read_unlock(); |
Jeff Moyer | 65c2449 | 2009-03-18 17:04:21 -0700 | [diff] [blame] | 1023 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1024 | } |
| 1025 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1026 | /* aio_complete |
| 1027 | * Called when the io request on the given iocb is complete. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1028 | */ |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 1029 | static void aio_complete(struct kiocb *kiocb, long res, long res2) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1030 | { |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 1031 | struct aio_kiocb *iocb = container_of(kiocb, struct aio_kiocb, common); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1032 | struct kioctx *ctx = iocb->ki_ctx; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1033 | struct aio_ring *ring; |
Kent Overstreet | 21b4020 | 2013-05-07 16:18:47 -0700 | [diff] [blame] | 1034 | struct io_event *ev_page, *event; |
Benjamin LaHaise | d856f32 | 2014-08-24 13:14:05 -0400 | [diff] [blame] | 1035 | unsigned tail, pos, head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1036 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1037 | |
Zach Brown | 20dcae3 | 2005-11-13 16:07:33 -0800 | [diff] [blame] | 1038 | /* |
| 1039 | * Special case handling for sync iocbs: |
| 1040 | * - events go directly into the iocb for fast handling |
| 1041 | * - the sync task with the iocb in its stack holds the single iocb |
| 1042 | * ref, no other paths have a way to get another ref |
| 1043 | * - the sync task helpfully left a reference to itself in the iocb |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1044 | */ |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 1045 | BUG_ON(is_sync_kiocb(kiocb)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1046 | |
Kent Overstreet | 0460fef | 2013-05-07 16:18:49 -0700 | [diff] [blame] | 1047 | if (iocb->ki_list.next) { |
| 1048 | unsigned long flags; |
| 1049 | |
| 1050 | spin_lock_irqsave(&ctx->ctx_lock, flags); |
| 1051 | list_del(&iocb->ki_list); |
| 1052 | spin_unlock_irqrestore(&ctx->ctx_lock, flags); |
| 1053 | } |
Kent Overstreet | 11599eb | 2013-05-07 16:18:39 -0700 | [diff] [blame] | 1054 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1055 | /* |
Kent Overstreet | 0460fef | 2013-05-07 16:18:49 -0700 | [diff] [blame] | 1056 | * Add a completion event to the ring buffer. Must be done holding |
Tang Chen | 4b30f07 | 2013-07-03 15:09:16 -0700 | [diff] [blame] | 1057 | * ctx->completion_lock to prevent other code from messing with the tail |
Kent Overstreet | 0460fef | 2013-05-07 16:18:49 -0700 | [diff] [blame] | 1058 | * pointer since we might be called from irq context. |
| 1059 | */ |
| 1060 | spin_lock_irqsave(&ctx->completion_lock, flags); |
| 1061 | |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 1062 | tail = ctx->tail; |
Kent Overstreet | 21b4020 | 2013-05-07 16:18:47 -0700 | [diff] [blame] | 1063 | pos = tail + AIO_EVENTS_OFFSET; |
| 1064 | |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 1065 | if (++tail >= ctx->nr_events) |
Ken Chen | 4bf69b2 | 2005-05-01 08:59:15 -0700 | [diff] [blame] | 1066 | tail = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1067 | |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 1068 | ev_page = kmap_atomic(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]); |
Kent Overstreet | 21b4020 | 2013-05-07 16:18:47 -0700 | [diff] [blame] | 1069 | event = ev_page + pos % AIO_EVENTS_PER_PAGE; |
| 1070 | |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 1071 | event->obj = (u64)(unsigned long)iocb->ki_user_iocb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1072 | event->data = iocb->ki_user_data; |
| 1073 | event->res = res; |
| 1074 | event->res2 = res2; |
| 1075 | |
Kent Overstreet | 21b4020 | 2013-05-07 16:18:47 -0700 | [diff] [blame] | 1076 | kunmap_atomic(ev_page); |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 1077 | flush_dcache_page(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]); |
Kent Overstreet | 21b4020 | 2013-05-07 16:18:47 -0700 | [diff] [blame] | 1078 | |
| 1079 | pr_debug("%p[%u]: %p: %p %Lx %lx %lx\n", |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 1080 | ctx, tail, iocb, iocb->ki_user_iocb, iocb->ki_user_data, |
Kent Overstreet | caf4167 | 2013-05-07 16:18:35 -0700 | [diff] [blame] | 1081 | res, res2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1082 | |
| 1083 | /* after flagging the request as done, we |
| 1084 | * must never even look at it again |
| 1085 | */ |
| 1086 | smp_wmb(); /* make event visible before updating tail */ |
| 1087 | |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 1088 | ctx->tail = tail; |
Kent Overstreet | 21b4020 | 2013-05-07 16:18:47 -0700 | [diff] [blame] | 1089 | |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 1090 | ring = kmap_atomic(ctx->ring_pages[0]); |
Benjamin LaHaise | d856f32 | 2014-08-24 13:14:05 -0400 | [diff] [blame] | 1091 | head = ring->head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1092 | ring->tail = tail; |
Cong Wang | e8e3c3d | 2011-11-25 23:14:27 +0800 | [diff] [blame] | 1093 | kunmap_atomic(ring); |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 1094 | flush_dcache_page(ctx->ring_pages[0]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1095 | |
Benjamin LaHaise | d856f32 | 2014-08-24 13:14:05 -0400 | [diff] [blame] | 1096 | ctx->completed_events++; |
| 1097 | if (ctx->completed_events > 1) |
| 1098 | refill_reqs_available(ctx, head, tail); |
Kent Overstreet | 0460fef | 2013-05-07 16:18:49 -0700 | [diff] [blame] | 1099 | spin_unlock_irqrestore(&ctx->completion_lock, flags); |
| 1100 | |
Kent Overstreet | 21b4020 | 2013-05-07 16:18:47 -0700 | [diff] [blame] | 1101 | pr_debug("added to ring %p at [%u]\n", iocb, tail); |
Davide Libenzi | 8d1c98b | 2008-04-10 21:29:19 -0700 | [diff] [blame] | 1102 | |
| 1103 | /* |
| 1104 | * Check if the user asked us to deliver the result through an |
| 1105 | * eventfd. The eventfd_signal() function is safe to be called |
| 1106 | * from IRQ context. |
| 1107 | */ |
Davide Libenzi | 87c3a86 | 2009-03-18 17:04:19 -0700 | [diff] [blame] | 1108 | if (iocb->ki_eventfd != NULL) |
Davide Libenzi | 8d1c98b | 2008-04-10 21:29:19 -0700 | [diff] [blame] | 1109 | eventfd_signal(iocb->ki_eventfd, 1); |
| 1110 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1111 | /* everything turned out well, dispose of the aiocb. */ |
Kent Overstreet | 57282d8 | 2013-05-13 13:42:52 -0700 | [diff] [blame] | 1112 | kiocb_free(iocb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1113 | |
Quentin Barnes | 6cb2a21 | 2008-03-19 17:00:39 -0700 | [diff] [blame] | 1114 | /* |
| 1115 | * We have to order our ring_info tail store above and test |
| 1116 | * of the wait list below outside the wait lock. This is |
| 1117 | * like in wake_up_bit() where clearing a bit has to be |
| 1118 | * ordered with the unlocked test. |
| 1119 | */ |
| 1120 | smp_mb(); |
| 1121 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1122 | if (waitqueue_active(&ctx->wait)) |
| 1123 | wake_up(&ctx->wait); |
| 1124 | |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 1125 | percpu_ref_put(&ctx->reqs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1126 | } |
| 1127 | |
Gu Zheng | 2be4e7d | 2014-07-23 18:03:53 +0800 | [diff] [blame] | 1128 | /* aio_read_events_ring |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1129 | * Pull an event off of the ioctx's event ring. Returns the number of |
| 1130 | * events fetched |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1131 | */ |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1132 | static long aio_read_events_ring(struct kioctx *ctx, |
| 1133 | struct io_event __user *event, long nr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1134 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1135 | struct aio_ring *ring; |
Kent Overstreet | 5ffac12 | 2013-05-09 15:36:07 -0700 | [diff] [blame] | 1136 | unsigned head, tail, pos; |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1137 | long ret = 0; |
| 1138 | int copy_ret; |
| 1139 | |
Dave Chinner | 9c9ce76 | 2015-02-03 19:29:05 -0500 | [diff] [blame] | 1140 | /* |
| 1141 | * The mutex can block and wake us up and that will cause |
| 1142 | * wait_event_interruptible_hrtimeout() to schedule without sleeping |
| 1143 | * and repeat. This should be rare enough that it doesn't cause |
| 1144 | * peformance issues. See the comment in read_events() for more detail. |
| 1145 | */ |
| 1146 | sched_annotate_sleep(); |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 1147 | mutex_lock(&ctx->ring_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1148 | |
Benjamin LaHaise | fa8a53c | 2014-03-28 10:14:45 -0400 | [diff] [blame] | 1149 | /* Access to ->ring_pages here is protected by ctx->ring_lock. */ |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 1150 | ring = kmap_atomic(ctx->ring_pages[0]); |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1151 | head = ring->head; |
Kent Overstreet | 5ffac12 | 2013-05-09 15:36:07 -0700 | [diff] [blame] | 1152 | tail = ring->tail; |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1153 | kunmap_atomic(ring); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1154 | |
Jeff Moyer | 2ff396be | 2014-09-02 13:17:00 -0400 | [diff] [blame] | 1155 | /* |
| 1156 | * Ensure that once we've read the current tail pointer, that |
| 1157 | * we also see the events that were stored up to the tail. |
| 1158 | */ |
| 1159 | smp_rmb(); |
| 1160 | |
Kent Overstreet | 5ffac12 | 2013-05-09 15:36:07 -0700 | [diff] [blame] | 1161 | pr_debug("h%u t%u m%u\n", head, tail, ctx->nr_events); |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1162 | |
Kent Overstreet | 5ffac12 | 2013-05-09 15:36:07 -0700 | [diff] [blame] | 1163 | if (head == tail) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1164 | goto out; |
| 1165 | |
Benjamin LaHaise | edfbbf3 | 2014-06-24 13:32:51 -0400 | [diff] [blame] | 1166 | head %= ctx->nr_events; |
| 1167 | tail %= ctx->nr_events; |
| 1168 | |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1169 | while (ret < nr) { |
| 1170 | long avail; |
| 1171 | struct io_event *ev; |
| 1172 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1173 | |
Kent Overstreet | 5ffac12 | 2013-05-09 15:36:07 -0700 | [diff] [blame] | 1174 | avail = (head <= tail ? tail : ctx->nr_events) - head; |
| 1175 | if (head == tail) |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1176 | break; |
| 1177 | |
| 1178 | avail = min(avail, nr - ret); |
| 1179 | avail = min_t(long, avail, AIO_EVENTS_PER_PAGE - |
| 1180 | ((head + AIO_EVENTS_OFFSET) % AIO_EVENTS_PER_PAGE)); |
| 1181 | |
| 1182 | pos = head + AIO_EVENTS_OFFSET; |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 1183 | page = ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]; |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1184 | pos %= AIO_EVENTS_PER_PAGE; |
| 1185 | |
| 1186 | ev = kmap(page); |
| 1187 | copy_ret = copy_to_user(event + ret, ev + pos, |
| 1188 | sizeof(*ev) * avail); |
| 1189 | kunmap(page); |
| 1190 | |
| 1191 | if (unlikely(copy_ret)) { |
| 1192 | ret = -EFAULT; |
| 1193 | goto out; |
| 1194 | } |
| 1195 | |
| 1196 | ret += avail; |
| 1197 | head += avail; |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 1198 | head %= ctx->nr_events; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1199 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1200 | |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 1201 | ring = kmap_atomic(ctx->ring_pages[0]); |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1202 | ring->head = head; |
Zhao Hongjiang | 91d80a8 | 2013-04-26 11:03:53 +0800 | [diff] [blame] | 1203 | kunmap_atomic(ring); |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 1204 | flush_dcache_page(ctx->ring_pages[0]); |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1205 | |
Kent Overstreet | 5ffac12 | 2013-05-09 15:36:07 -0700 | [diff] [blame] | 1206 | pr_debug("%li h%u t%u\n", ret, head, tail); |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1207 | out: |
Kent Overstreet | 58c85dc | 2013-05-07 16:18:55 -0700 | [diff] [blame] | 1208 | mutex_unlock(&ctx->ring_lock); |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1209 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1210 | return ret; |
| 1211 | } |
| 1212 | |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1213 | static bool aio_read_events(struct kioctx *ctx, long min_nr, long nr, |
| 1214 | struct io_event __user *event, long *i) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1215 | { |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1216 | long ret = aio_read_events_ring(ctx, event + *i, nr - *i); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1217 | |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1218 | if (ret > 0) |
| 1219 | *i += ret; |
| 1220 | |
| 1221 | if (unlikely(atomic_read(&ctx->dead))) |
| 1222 | ret = -EINVAL; |
| 1223 | |
| 1224 | if (!*i) |
| 1225 | *i = ret; |
| 1226 | |
| 1227 | return ret < 0 || *i >= min_nr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1228 | } |
| 1229 | |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1230 | static long read_events(struct kioctx *ctx, long min_nr, long nr, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1231 | struct io_event __user *event, |
| 1232 | struct timespec __user *timeout) |
| 1233 | { |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1234 | ktime_t until = { .tv64 = KTIME_MAX }; |
| 1235 | long ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1236 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1237 | if (timeout) { |
| 1238 | struct timespec ts; |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1239 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1240 | if (unlikely(copy_from_user(&ts, timeout, sizeof(ts)))) |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1241 | return -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1242 | |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1243 | until = timespec_to_ktime(ts); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1244 | } |
| 1245 | |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1246 | /* |
| 1247 | * Note that aio_read_events() is being called as the conditional - i.e. |
| 1248 | * we're calling it after prepare_to_wait() has set task state to |
| 1249 | * TASK_INTERRUPTIBLE. |
| 1250 | * |
| 1251 | * But aio_read_events() can block, and if it blocks it's going to flip |
| 1252 | * the task state back to TASK_RUNNING. |
| 1253 | * |
| 1254 | * This should be ok, provided it doesn't flip the state back to |
| 1255 | * TASK_RUNNING and return 0 too much - that causes us to spin. That |
| 1256 | * will only happen if the mutex_lock() call blocks, and we then find |
| 1257 | * the ringbuffer empty. So in practice we should be ok, but it's |
| 1258 | * something to be aware of when touching this code. |
| 1259 | */ |
Fam Zheng | 5f785de | 2014-11-06 20:44:36 +0800 | [diff] [blame] | 1260 | if (until.tv64 == 0) |
| 1261 | aio_read_events(ctx, min_nr, nr, event, &ret); |
| 1262 | else |
| 1263 | wait_event_interruptible_hrtimeout(ctx->wait, |
| 1264 | aio_read_events(ctx, min_nr, nr, event, &ret), |
| 1265 | until); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1266 | |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1267 | if (!ret && signal_pending(current)) |
| 1268 | ret = -EINTR; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1269 | |
Kent Overstreet | a31ad38 | 2013-05-07 16:18:45 -0700 | [diff] [blame] | 1270 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1271 | } |
| 1272 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1273 | /* sys_io_setup: |
| 1274 | * Create an aio_context capable of receiving at least nr_events. |
| 1275 | * ctxp must not point to an aio_context that already exists, and |
| 1276 | * must be initialized to 0 prior to the call. On successful |
| 1277 | * creation of the aio_context, *ctxp is filled in with the resulting |
| 1278 | * handle. May fail with -EINVAL if *ctxp is not initialized, |
| 1279 | * if the specified nr_events exceeds internal limits. May fail |
| 1280 | * with -EAGAIN if the specified nr_events exceeds the user's limit |
| 1281 | * of available events. May fail with -ENOMEM if insufficient kernel |
| 1282 | * resources are available. May fail with -EFAULT if an invalid |
| 1283 | * pointer is passed for ctxp. Will fail with -ENOSYS if not |
| 1284 | * implemented. |
| 1285 | */ |
Heiko Carstens | 002c897 | 2009-01-14 14:14:18 +0100 | [diff] [blame] | 1286 | SYSCALL_DEFINE2(io_setup, unsigned, nr_events, aio_context_t __user *, ctxp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1287 | { |
| 1288 | struct kioctx *ioctx = NULL; |
| 1289 | unsigned long ctx; |
| 1290 | long ret; |
| 1291 | |
| 1292 | ret = get_user(ctx, ctxp); |
| 1293 | if (unlikely(ret)) |
| 1294 | goto out; |
| 1295 | |
| 1296 | ret = -EINVAL; |
Zach Brown | d55b5fd | 2005-11-07 00:59:31 -0800 | [diff] [blame] | 1297 | if (unlikely(ctx || nr_events == 0)) { |
Kinglong Mee | acd88d4 | 2015-02-04 21:15:59 +0800 | [diff] [blame] | 1298 | pr_debug("EINVAL: ctx %lu nr_events %u\n", |
Zach Brown | d55b5fd | 2005-11-07 00:59:31 -0800 | [diff] [blame] | 1299 | ctx, nr_events); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1300 | goto out; |
| 1301 | } |
| 1302 | |
| 1303 | ioctx = ioctx_alloc(nr_events); |
| 1304 | ret = PTR_ERR(ioctx); |
| 1305 | if (!IS_ERR(ioctx)) { |
| 1306 | ret = put_user(ioctx->user_id, ctxp); |
Al Viro | a2e1859 | 2012-03-20 16:27:57 -0400 | [diff] [blame] | 1307 | if (ret) |
Anatol Pomozov | e02ba72 | 2014-04-15 11:31:33 -0700 | [diff] [blame] | 1308 | kill_ioctx(current->mm, ioctx, NULL); |
Kent Overstreet | 723be6e | 2013-05-28 15:14:48 -0700 | [diff] [blame] | 1309 | percpu_ref_put(&ioctx->users); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1310 | } |
| 1311 | |
| 1312 | out: |
| 1313 | return ret; |
| 1314 | } |
| 1315 | |
| 1316 | /* sys_io_destroy: |
| 1317 | * Destroy the aio_context specified. May cancel any outstanding |
| 1318 | * AIOs and block on completion. Will fail with -ENOSYS if not |
Satoru Takeuchi | 642b512 | 2010-08-05 11:23:11 -0700 | [diff] [blame] | 1319 | * implemented. May fail with -EINVAL if the context pointed to |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1320 | * is invalid. |
| 1321 | */ |
Heiko Carstens | 002c897 | 2009-01-14 14:14:18 +0100 | [diff] [blame] | 1322 | SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1323 | { |
| 1324 | struct kioctx *ioctx = lookup_ioctx(ctx); |
| 1325 | if (likely(NULL != ioctx)) { |
Anatol Pomozov | e02ba72 | 2014-04-15 11:31:33 -0700 | [diff] [blame] | 1326 | struct completion requests_done = |
| 1327 | COMPLETION_INITIALIZER_ONSTACK(requests_done); |
Benjamin LaHaise | fb2d448 | 2014-04-29 12:45:17 -0400 | [diff] [blame] | 1328 | int ret; |
Anatol Pomozov | e02ba72 | 2014-04-15 11:31:33 -0700 | [diff] [blame] | 1329 | |
| 1330 | /* Pass requests_done to kill_ioctx() where it can be set |
| 1331 | * in a thread-safe way. If we try to set it here then we have |
| 1332 | * a race condition if two io_destroy() called simultaneously. |
| 1333 | */ |
Benjamin LaHaise | fb2d448 | 2014-04-29 12:45:17 -0400 | [diff] [blame] | 1334 | ret = kill_ioctx(current->mm, ioctx, &requests_done); |
Kent Overstreet | 723be6e | 2013-05-28 15:14:48 -0700 | [diff] [blame] | 1335 | percpu_ref_put(&ioctx->users); |
Anatol Pomozov | e02ba72 | 2014-04-15 11:31:33 -0700 | [diff] [blame] | 1336 | |
| 1337 | /* Wait until all IO for the context are done. Otherwise kernel |
| 1338 | * keep using user-space buffers even if user thinks the context |
| 1339 | * is destroyed. |
| 1340 | */ |
Benjamin LaHaise | fb2d448 | 2014-04-29 12:45:17 -0400 | [diff] [blame] | 1341 | if (!ret) |
| 1342 | wait_for_completion(&requests_done); |
Anatol Pomozov | e02ba72 | 2014-04-15 11:31:33 -0700 | [diff] [blame] | 1343 | |
Benjamin LaHaise | fb2d448 | 2014-04-29 12:45:17 -0400 | [diff] [blame] | 1344 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1345 | } |
Kinglong Mee | acd88d4 | 2015-02-04 21:15:59 +0800 | [diff] [blame] | 1346 | pr_debug("EINVAL: invalid context id\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1347 | return -EINVAL; |
| 1348 | } |
| 1349 | |
Al Viro | 293bc98 | 2014-02-11 18:37:41 -0500 | [diff] [blame] | 1350 | typedef ssize_t (rw_iter_op)(struct kiocb *, struct iov_iter *); |
Kent Overstreet | 41ef4eb | 2013-05-07 16:19:11 -0700 | [diff] [blame] | 1351 | |
Al Viro | a96114f | 2015-03-20 20:40:18 -0400 | [diff] [blame] | 1352 | static int aio_setup_vectored_rw(int rw, char __user *buf, size_t len, |
| 1353 | struct iovec **iovec, |
| 1354 | bool compat, |
| 1355 | struct iov_iter *iter) |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 1356 | { |
Jeff Moyer | 9d85cba | 2010-05-26 14:44:26 -0700 | [diff] [blame] | 1357 | #ifdef CONFIG_COMPAT |
| 1358 | if (compat) |
Al Viro | 32a56af | 2015-03-21 19:34:53 -0400 | [diff] [blame] | 1359 | return compat_import_iovec(rw, |
Kent Overstreet | 8bc92af | 2013-02-25 16:36:27 -0800 | [diff] [blame] | 1360 | (struct compat_iovec __user *)buf, |
Al Viro | 32a56af | 2015-03-21 19:34:53 -0400 | [diff] [blame] | 1361 | len, UIO_FASTIOV, iovec, iter); |
Jeff Moyer | 9d85cba | 2010-05-26 14:44:26 -0700 | [diff] [blame] | 1362 | #endif |
Al Viro | 32a56af | 2015-03-21 19:34:53 -0400 | [diff] [blame] | 1363 | return import_iovec(rw, (struct iovec __user *)buf, |
| 1364 | len, UIO_FASTIOV, iovec, iter); |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 1365 | } |
| 1366 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1367 | /* |
Gu Zheng | 2be4e7d | 2014-07-23 18:03:53 +0800 | [diff] [blame] | 1368 | * aio_run_iocb: |
| 1369 | * Performs the initial checks and io submission. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1370 | */ |
Kent Overstreet | 8bc92af | 2013-02-25 16:36:27 -0800 | [diff] [blame] | 1371 | static ssize_t aio_run_iocb(struct kiocb *req, unsigned opcode, |
Christoph Hellwig | 66ee59a | 2015-02-11 19:56:46 +0100 | [diff] [blame] | 1372 | char __user *buf, size_t len, bool compat) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1373 | { |
Kent Overstreet | 41ef4eb | 2013-05-07 16:19:11 -0700 | [diff] [blame] | 1374 | struct file *file = req->ki_filp; |
| 1375 | ssize_t ret; |
| 1376 | int rw; |
| 1377 | fmode_t mode; |
Al Viro | 293bc98 | 2014-02-11 18:37:41 -0500 | [diff] [blame] | 1378 | rw_iter_op *iter_op; |
Gu Zheng | 00fefb9 | 2014-07-23 18:03:54 +0800 | [diff] [blame] | 1379 | struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; |
Al Viro | 293bc98 | 2014-02-11 18:37:41 -0500 | [diff] [blame] | 1380 | struct iov_iter iter; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1381 | |
Kent Overstreet | 8bc92af | 2013-02-25 16:36:27 -0800 | [diff] [blame] | 1382 | switch (opcode) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1383 | case IOCB_CMD_PREAD: |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 1384 | case IOCB_CMD_PREADV: |
Kent Overstreet | 41ef4eb | 2013-05-07 16:19:11 -0700 | [diff] [blame] | 1385 | mode = FMODE_READ; |
| 1386 | rw = READ; |
Al Viro | 293bc98 | 2014-02-11 18:37:41 -0500 | [diff] [blame] | 1387 | iter_op = file->f_op->read_iter; |
Kent Overstreet | 41ef4eb | 2013-05-07 16:19:11 -0700 | [diff] [blame] | 1388 | goto rw_common; |
| 1389 | |
| 1390 | case IOCB_CMD_PWRITE: |
Badari Pulavarty | eed4e51 | 2006-09-30 23:28:49 -0700 | [diff] [blame] | 1391 | case IOCB_CMD_PWRITEV: |
Kent Overstreet | 41ef4eb | 2013-05-07 16:19:11 -0700 | [diff] [blame] | 1392 | mode = FMODE_WRITE; |
| 1393 | rw = WRITE; |
Al Viro | 293bc98 | 2014-02-11 18:37:41 -0500 | [diff] [blame] | 1394 | iter_op = file->f_op->write_iter; |
Kent Overstreet | 41ef4eb | 2013-05-07 16:19:11 -0700 | [diff] [blame] | 1395 | goto rw_common; |
| 1396 | rw_common: |
| 1397 | if (unlikely(!(file->f_mode & mode))) |
| 1398 | return -EBADF; |
| 1399 | |
Al Viro | 8436318 | 2015-04-04 01:14:53 -0400 | [diff] [blame^] | 1400 | if (!iter_op) |
Kent Overstreet | 41ef4eb | 2013-05-07 16:19:11 -0700 | [diff] [blame] | 1401 | return -EINVAL; |
| 1402 | |
Christoph Hellwig | 66ee59a | 2015-02-11 19:56:46 +0100 | [diff] [blame] | 1403 | if (opcode == IOCB_CMD_PREADV || opcode == IOCB_CMD_PWRITEV) |
Al Viro | a96114f | 2015-03-20 20:40:18 -0400 | [diff] [blame] | 1404 | ret = aio_setup_vectored_rw(rw, buf, len, |
| 1405 | &iovec, compat, &iter); |
Al Viro | 32a56af | 2015-03-21 19:34:53 -0400 | [diff] [blame] | 1406 | else { |
Al Viro | d4fb392 | 2015-03-21 19:11:55 -0400 | [diff] [blame] | 1407 | ret = import_single_range(rw, buf, len, iovec, &iter); |
Al Viro | 32a56af | 2015-03-21 19:34:53 -0400 | [diff] [blame] | 1408 | iovec = NULL; |
| 1409 | } |
Leon Yu | 754320d | 2014-05-01 03:31:28 +0000 | [diff] [blame] | 1410 | if (!ret) |
Al Viro | a96114f | 2015-03-20 20:40:18 -0400 | [diff] [blame] | 1411 | ret = rw_verify_area(rw, file, &req->ki_pos, |
| 1412 | iov_iter_count(&iter)); |
Kent Overstreet | 8bc92af | 2013-02-25 16:36:27 -0800 | [diff] [blame] | 1413 | if (ret < 0) { |
Al Viro | 32a56af | 2015-03-21 19:34:53 -0400 | [diff] [blame] | 1414 | kfree(iovec); |
Kent Overstreet | 41ef4eb | 2013-05-07 16:19:11 -0700 | [diff] [blame] | 1415 | return ret; |
Kent Overstreet | 8bc92af | 2013-02-25 16:36:27 -0800 | [diff] [blame] | 1416 | } |
Kent Overstreet | 41ef4eb | 2013-05-07 16:19:11 -0700 | [diff] [blame] | 1417 | |
Christoph Hellwig | 66ee59a | 2015-02-11 19:56:46 +0100 | [diff] [blame] | 1418 | len = ret; |
Kent Overstreet | 41ef4eb | 2013-05-07 16:19:11 -0700 | [diff] [blame] | 1419 | |
Kent Overstreet | 73a7075 | 2013-05-09 15:03:42 -0700 | [diff] [blame] | 1420 | if (rw == WRITE) |
| 1421 | file_start_write(file); |
| 1422 | |
Al Viro | 8436318 | 2015-04-04 01:14:53 -0400 | [diff] [blame^] | 1423 | ret = iter_op(req, &iter); |
Kent Overstreet | 73a7075 | 2013-05-09 15:03:42 -0700 | [diff] [blame] | 1424 | |
| 1425 | if (rw == WRITE) |
| 1426 | file_end_write(file); |
Al Viro | 32a56af | 2015-03-21 19:34:53 -0400 | [diff] [blame] | 1427 | kfree(iovec); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1428 | break; |
Kent Overstreet | 41ef4eb | 2013-05-07 16:19:11 -0700 | [diff] [blame] | 1429 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1430 | case IOCB_CMD_FDSYNC: |
Kent Overstreet | 41ef4eb | 2013-05-07 16:19:11 -0700 | [diff] [blame] | 1431 | if (!file->f_op->aio_fsync) |
| 1432 | return -EINVAL; |
| 1433 | |
| 1434 | ret = file->f_op->aio_fsync(req, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1435 | break; |
Kent Overstreet | 41ef4eb | 2013-05-07 16:19:11 -0700 | [diff] [blame] | 1436 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1437 | case IOCB_CMD_FSYNC: |
Kent Overstreet | 41ef4eb | 2013-05-07 16:19:11 -0700 | [diff] [blame] | 1438 | if (!file->f_op->aio_fsync) |
| 1439 | return -EINVAL; |
| 1440 | |
| 1441 | ret = file->f_op->aio_fsync(req, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1442 | break; |
Kent Overstreet | 41ef4eb | 2013-05-07 16:19:11 -0700 | [diff] [blame] | 1443 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1444 | default: |
Kent Overstreet | caf4167 | 2013-05-07 16:18:35 -0700 | [diff] [blame] | 1445 | pr_debug("EINVAL: no operation provided\n"); |
Kent Overstreet | 41ef4eb | 2013-05-07 16:19:11 -0700 | [diff] [blame] | 1446 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1447 | } |
| 1448 | |
Kent Overstreet | 41ef4eb | 2013-05-07 16:19:11 -0700 | [diff] [blame] | 1449 | if (ret != -EIOCBQUEUED) { |
| 1450 | /* |
| 1451 | * There's no easy way to restart the syscall since other AIO's |
| 1452 | * may be already running. Just fail this IO with EINTR. |
| 1453 | */ |
| 1454 | if (unlikely(ret == -ERESTARTSYS || ret == -ERESTARTNOINTR || |
| 1455 | ret == -ERESTARTNOHAND || |
| 1456 | ret == -ERESTART_RESTARTBLOCK)) |
| 1457 | ret = -EINTR; |
| 1458 | aio_complete(req, ret, 0); |
| 1459 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1460 | |
| 1461 | return 0; |
| 1462 | } |
| 1463 | |
Adrian Bunk | d5470b5 | 2008-04-29 00:58:57 -0700 | [diff] [blame] | 1464 | static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, |
Kent Overstreet | a1c8eae | 2013-05-07 16:18:53 -0700 | [diff] [blame] | 1465 | struct iocb *iocb, bool compat) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1466 | { |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 1467 | struct aio_kiocb *req; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1468 | ssize_t ret; |
| 1469 | |
| 1470 | /* enforce forwards compatibility on users */ |
Davide Libenzi | 9c3060b | 2007-05-10 22:23:21 -0700 | [diff] [blame] | 1471 | if (unlikely(iocb->aio_reserved1 || iocb->aio_reserved2)) { |
Kent Overstreet | caf4167 | 2013-05-07 16:18:35 -0700 | [diff] [blame] | 1472 | pr_debug("EINVAL: reserve field set\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1473 | return -EINVAL; |
| 1474 | } |
| 1475 | |
| 1476 | /* prevent overflows */ |
| 1477 | if (unlikely( |
| 1478 | (iocb->aio_buf != (unsigned long)iocb->aio_buf) || |
| 1479 | (iocb->aio_nbytes != (size_t)iocb->aio_nbytes) || |
| 1480 | ((ssize_t)iocb->aio_nbytes < 0) |
| 1481 | )) { |
Kinglong Mee | acd88d4 | 2015-02-04 21:15:59 +0800 | [diff] [blame] | 1482 | pr_debug("EINVAL: overflow check\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1483 | return -EINVAL; |
| 1484 | } |
| 1485 | |
Kent Overstreet | 41ef4eb | 2013-05-07 16:19:11 -0700 | [diff] [blame] | 1486 | req = aio_get_req(ctx); |
Kent Overstreet | 1d98ebf | 2013-05-07 16:18:37 -0700 | [diff] [blame] | 1487 | if (unlikely(!req)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1488 | return -EAGAIN; |
Kent Overstreet | 1d98ebf | 2013-05-07 16:18:37 -0700 | [diff] [blame] | 1489 | |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 1490 | req->common.ki_filp = fget(iocb->aio_fildes); |
| 1491 | if (unlikely(!req->common.ki_filp)) { |
Kent Overstreet | 1d98ebf | 2013-05-07 16:18:37 -0700 | [diff] [blame] | 1492 | ret = -EBADF; |
| 1493 | goto out_put_req; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1494 | } |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 1495 | req->common.ki_pos = iocb->aio_offset; |
| 1496 | req->common.ki_complete = aio_complete; |
| 1497 | req->common.ki_flags = 0; |
Kent Overstreet | 1d98ebf | 2013-05-07 16:18:37 -0700 | [diff] [blame] | 1498 | |
Davide Libenzi | 9c3060b | 2007-05-10 22:23:21 -0700 | [diff] [blame] | 1499 | if (iocb->aio_flags & IOCB_FLAG_RESFD) { |
| 1500 | /* |
| 1501 | * If the IOCB_FLAG_RESFD flag of aio_flags is set, get an |
| 1502 | * instance of the file* now. The file descriptor must be |
| 1503 | * an eventfd() fd, and will be signaled for each completed |
| 1504 | * event using the eventfd_signal() function. |
| 1505 | */ |
Davide Libenzi | 1338901 | 2009-06-30 11:41:11 -0700 | [diff] [blame] | 1506 | req->ki_eventfd = eventfd_ctx_fdget((int) iocb->aio_resfd); |
Hirofumi Nakagawa | 801678c | 2008-04-29 01:03:09 -0700 | [diff] [blame] | 1507 | if (IS_ERR(req->ki_eventfd)) { |
Davide Libenzi | 9c3060b | 2007-05-10 22:23:21 -0700 | [diff] [blame] | 1508 | ret = PTR_ERR(req->ki_eventfd); |
Davide Libenzi | 87c3a86 | 2009-03-18 17:04:19 -0700 | [diff] [blame] | 1509 | req->ki_eventfd = NULL; |
Davide Libenzi | 9c3060b | 2007-05-10 22:23:21 -0700 | [diff] [blame] | 1510 | goto out_put_req; |
| 1511 | } |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 1512 | |
| 1513 | req->common.ki_flags |= IOCB_EVENTFD; |
Davide Libenzi | 9c3060b | 2007-05-10 22:23:21 -0700 | [diff] [blame] | 1514 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1515 | |
Kent Overstreet | 8a66089 | 2013-05-07 16:19:10 -0700 | [diff] [blame] | 1516 | ret = put_user(KIOCB_KEY, &user_iocb->aio_key); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1517 | if (unlikely(ret)) { |
Kent Overstreet | caf4167 | 2013-05-07 16:18:35 -0700 | [diff] [blame] | 1518 | pr_debug("EFAULT: aio_key\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1519 | goto out_put_req; |
| 1520 | } |
| 1521 | |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 1522 | req->ki_user_iocb = user_iocb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1523 | req->ki_user_data = iocb->aio_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1524 | |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 1525 | ret = aio_run_iocb(&req->common, iocb->aio_lio_opcode, |
Kent Overstreet | 8bc92af | 2013-02-25 16:36:27 -0800 | [diff] [blame] | 1526 | (char __user *)(unsigned long)iocb->aio_buf, |
Christoph Hellwig | 66ee59a | 2015-02-11 19:56:46 +0100 | [diff] [blame] | 1527 | iocb->aio_nbytes, |
Kent Overstreet | 8bc92af | 2013-02-25 16:36:27 -0800 | [diff] [blame] | 1528 | compat); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1529 | if (ret) |
| 1530 | goto out_put_req; |
| 1531 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1532 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1533 | out_put_req: |
Kent Overstreet | e1bdd5f | 2013-04-26 10:58:39 +1000 | [diff] [blame] | 1534 | put_reqs_available(ctx, 1); |
Kent Overstreet | e34ecee | 2013-10-10 19:31:47 -0700 | [diff] [blame] | 1535 | percpu_ref_put(&ctx->reqs); |
Kent Overstreet | 57282d8 | 2013-05-13 13:42:52 -0700 | [diff] [blame] | 1536 | kiocb_free(req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1537 | return ret; |
| 1538 | } |
| 1539 | |
Jeff Moyer | 9d85cba | 2010-05-26 14:44:26 -0700 | [diff] [blame] | 1540 | long do_io_submit(aio_context_t ctx_id, long nr, |
| 1541 | struct iocb __user *__user *iocbpp, bool compat) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1542 | { |
| 1543 | struct kioctx *ctx; |
| 1544 | long ret = 0; |
Jeff Moyer | 080d676 | 2011-11-02 13:40:10 -0700 | [diff] [blame] | 1545 | int i = 0; |
Shaohua Li | 9f5b942 | 2010-07-01 07:55:01 +0200 | [diff] [blame] | 1546 | struct blk_plug plug; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1547 | |
| 1548 | if (unlikely(nr < 0)) |
| 1549 | return -EINVAL; |
| 1550 | |
Jeff Moyer | 75e1c70 | 2010-09-10 14:16:00 -0700 | [diff] [blame] | 1551 | if (unlikely(nr > LONG_MAX/sizeof(*iocbpp))) |
| 1552 | nr = LONG_MAX/sizeof(*iocbpp); |
| 1553 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1554 | if (unlikely(!access_ok(VERIFY_READ, iocbpp, (nr*sizeof(*iocbpp))))) |
| 1555 | return -EFAULT; |
| 1556 | |
| 1557 | ctx = lookup_ioctx(ctx_id); |
| 1558 | if (unlikely(!ctx)) { |
Kent Overstreet | caf4167 | 2013-05-07 16:18:35 -0700 | [diff] [blame] | 1559 | pr_debug("EINVAL: invalid context id\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1560 | return -EINVAL; |
| 1561 | } |
| 1562 | |
Shaohua Li | 9f5b942 | 2010-07-01 07:55:01 +0200 | [diff] [blame] | 1563 | blk_start_plug(&plug); |
| 1564 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1565 | /* |
| 1566 | * AKPM: should this return a partial result if some of the IOs were |
| 1567 | * successfully submitted? |
| 1568 | */ |
| 1569 | for (i=0; i<nr; i++) { |
| 1570 | struct iocb __user *user_iocb; |
| 1571 | struct iocb tmp; |
| 1572 | |
| 1573 | if (unlikely(__get_user(user_iocb, iocbpp + i))) { |
| 1574 | ret = -EFAULT; |
| 1575 | break; |
| 1576 | } |
| 1577 | |
| 1578 | if (unlikely(copy_from_user(&tmp, user_iocb, sizeof(tmp)))) { |
| 1579 | ret = -EFAULT; |
| 1580 | break; |
| 1581 | } |
| 1582 | |
Kent Overstreet | a1c8eae | 2013-05-07 16:18:53 -0700 | [diff] [blame] | 1583 | ret = io_submit_one(ctx, user_iocb, &tmp, compat); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1584 | if (ret) |
| 1585 | break; |
| 1586 | } |
Shaohua Li | 9f5b942 | 2010-07-01 07:55:01 +0200 | [diff] [blame] | 1587 | blk_finish_plug(&plug); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1588 | |
Kent Overstreet | 723be6e | 2013-05-28 15:14:48 -0700 | [diff] [blame] | 1589 | percpu_ref_put(&ctx->users); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1590 | return i ? i : ret; |
| 1591 | } |
| 1592 | |
Jeff Moyer | 9d85cba | 2010-05-26 14:44:26 -0700 | [diff] [blame] | 1593 | /* sys_io_submit: |
| 1594 | * Queue the nr iocbs pointed to by iocbpp for processing. Returns |
| 1595 | * the number of iocbs queued. May return -EINVAL if the aio_context |
| 1596 | * specified by ctx_id is invalid, if nr is < 0, if the iocb at |
| 1597 | * *iocbpp[0] is not properly initialized, if the operation specified |
| 1598 | * is invalid for the file descriptor in the iocb. May fail with |
| 1599 | * -EFAULT if any of the data structures point to invalid data. May |
| 1600 | * fail with -EBADF if the file descriptor specified in the first |
| 1601 | * iocb is invalid. May fail with -EAGAIN if insufficient resources |
| 1602 | * are available to queue any iocbs. Will return 0 if nr is 0. Will |
| 1603 | * fail with -ENOSYS if not implemented. |
| 1604 | */ |
| 1605 | SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr, |
| 1606 | struct iocb __user * __user *, iocbpp) |
| 1607 | { |
| 1608 | return do_io_submit(ctx_id, nr, iocbpp, 0); |
| 1609 | } |
| 1610 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1611 | /* lookup_kiocb |
| 1612 | * Finds a given iocb for cancellation. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1613 | */ |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 1614 | static struct aio_kiocb * |
| 1615 | lookup_kiocb(struct kioctx *ctx, struct iocb __user *iocb, u32 key) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1616 | { |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 1617 | struct aio_kiocb *kiocb; |
Zach Brown | d00689a | 2005-11-13 16:07:34 -0800 | [diff] [blame] | 1618 | |
| 1619 | assert_spin_locked(&ctx->ctx_lock); |
| 1620 | |
Kent Overstreet | 8a66089 | 2013-05-07 16:19:10 -0700 | [diff] [blame] | 1621 | if (key != KIOCB_KEY) |
| 1622 | return NULL; |
| 1623 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1624 | /* TODO: use a hash or array, this sucks. */ |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 1625 | list_for_each_entry(kiocb, &ctx->active_reqs, ki_list) { |
| 1626 | if (kiocb->ki_user_iocb == iocb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1627 | return kiocb; |
| 1628 | } |
| 1629 | return NULL; |
| 1630 | } |
| 1631 | |
| 1632 | /* sys_io_cancel: |
| 1633 | * Attempts to cancel an iocb previously passed to io_submit. If |
| 1634 | * the operation is successfully cancelled, the resulting event is |
| 1635 | * copied into the memory pointed to by result without being placed |
| 1636 | * into the completion queue and 0 is returned. May fail with |
| 1637 | * -EFAULT if any of the data structures pointed to are invalid. |
| 1638 | * May fail with -EINVAL if aio_context specified by ctx_id is |
| 1639 | * invalid. May fail with -EAGAIN if the iocb specified was not |
| 1640 | * cancelled. Will fail with -ENOSYS if not implemented. |
| 1641 | */ |
Heiko Carstens | 002c897 | 2009-01-14 14:14:18 +0100 | [diff] [blame] | 1642 | SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb, |
| 1643 | struct io_event __user *, result) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1644 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1645 | struct kioctx *ctx; |
Christoph Hellwig | 04b2fa9 | 2015-02-02 14:49:06 +0100 | [diff] [blame] | 1646 | struct aio_kiocb *kiocb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1647 | u32 key; |
| 1648 | int ret; |
| 1649 | |
| 1650 | ret = get_user(key, &iocb->aio_key); |
| 1651 | if (unlikely(ret)) |
| 1652 | return -EFAULT; |
| 1653 | |
| 1654 | ctx = lookup_ioctx(ctx_id); |
| 1655 | if (unlikely(!ctx)) |
| 1656 | return -EINVAL; |
| 1657 | |
| 1658 | spin_lock_irq(&ctx->ctx_lock); |
Kent Overstreet | 906b973 | 2013-05-07 16:18:31 -0700 | [diff] [blame] | 1659 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1660 | kiocb = lookup_kiocb(ctx, iocb, key); |
Kent Overstreet | 906b973 | 2013-05-07 16:18:31 -0700 | [diff] [blame] | 1661 | if (kiocb) |
Fabian Frederick | d52a8f9 | 2014-04-22 07:26:58 +0200 | [diff] [blame] | 1662 | ret = kiocb_cancel(kiocb); |
Kent Overstreet | 906b973 | 2013-05-07 16:18:31 -0700 | [diff] [blame] | 1663 | else |
| 1664 | ret = -EINVAL; |
| 1665 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1666 | spin_unlock_irq(&ctx->ctx_lock); |
| 1667 | |
Kent Overstreet | 906b973 | 2013-05-07 16:18:31 -0700 | [diff] [blame] | 1668 | if (!ret) { |
Kent Overstreet | bec68faa | 2013-05-13 14:45:08 -0700 | [diff] [blame] | 1669 | /* |
| 1670 | * The result argument is no longer used - the io_event is |
| 1671 | * always delivered via the ring buffer. -EINPROGRESS indicates |
| 1672 | * cancellation is progress: |
Kent Overstreet | 906b973 | 2013-05-07 16:18:31 -0700 | [diff] [blame] | 1673 | */ |
Kent Overstreet | bec68faa | 2013-05-13 14:45:08 -0700 | [diff] [blame] | 1674 | ret = -EINPROGRESS; |
Kent Overstreet | 906b973 | 2013-05-07 16:18:31 -0700 | [diff] [blame] | 1675 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1676 | |
Kent Overstreet | 723be6e | 2013-05-28 15:14:48 -0700 | [diff] [blame] | 1677 | percpu_ref_put(&ctx->users); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1678 | |
| 1679 | return ret; |
| 1680 | } |
| 1681 | |
| 1682 | /* io_getevents: |
| 1683 | * Attempts to read at least min_nr events and up to nr events from |
Satoru Takeuchi | 642b512 | 2010-08-05 11:23:11 -0700 | [diff] [blame] | 1684 | * the completion queue for the aio_context specified by ctx_id. If |
| 1685 | * it succeeds, the number of read events is returned. May fail with |
| 1686 | * -EINVAL if ctx_id is invalid, if min_nr is out of range, if nr is |
| 1687 | * out of range, if timeout is out of range. May fail with -EFAULT |
| 1688 | * if any of the memory specified is invalid. May return 0 or |
| 1689 | * < min_nr if the timeout specified by timeout has elapsed |
| 1690 | * before sufficient events are available, where timeout == NULL |
| 1691 | * specifies an infinite timeout. Note that the timeout pointed to by |
Jeff Moyer | 6900807 | 2013-05-24 15:55:24 -0700 | [diff] [blame] | 1692 | * timeout is relative. Will fail with -ENOSYS if not implemented. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1693 | */ |
Heiko Carstens | 002c897 | 2009-01-14 14:14:18 +0100 | [diff] [blame] | 1694 | SYSCALL_DEFINE5(io_getevents, aio_context_t, ctx_id, |
| 1695 | long, min_nr, |
| 1696 | long, nr, |
| 1697 | struct io_event __user *, events, |
| 1698 | struct timespec __user *, timeout) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1699 | { |
| 1700 | struct kioctx *ioctx = lookup_ioctx(ctx_id); |
| 1701 | long ret = -EINVAL; |
| 1702 | |
| 1703 | if (likely(ioctx)) { |
Namhyung Kim | 2e41025 | 2011-01-12 17:01:08 -0800 | [diff] [blame] | 1704 | if (likely(min_nr <= nr && min_nr >= 0)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1705 | ret = read_events(ioctx, min_nr, nr, events, timeout); |
Kent Overstreet | 723be6e | 2013-05-28 15:14:48 -0700 | [diff] [blame] | 1706 | percpu_ref_put(&ioctx->users); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1707 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1708 | return ret; |
| 1709 | } |