Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * POSIX message queues filesystem for Linux. |
| 3 | * |
| 4 | * Copyright (C) 2003,2004 Krzysztof Benedyczak (golbi@mat.uni.torun.pl) |
Michal Wronski | f66e928 | 2006-10-03 23:23:27 +0200 | [diff] [blame] | 5 | * Michal Wronski (michal.wronski@gmail.com) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | * |
| 7 | * Spinlocks: Mohamed Abbas (abbas.mohamed@intel.com) |
| 8 | * Lockless receive & send, fd based notify: |
| 9 | * Manfred Spraul (manfred@colorfullife.com) |
| 10 | * |
George C. Wilson | 20ca73b | 2006-05-24 16:09:55 -0500 | [diff] [blame] | 11 | * Audit: George Wilson (ltcgcw@us.ibm.com) |
| 12 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | * This file is released under the GPL. |
| 14 | */ |
| 15 | |
Randy.Dunlap | c59ede7 | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 16 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/init.h> |
| 18 | #include <linux/pagemap.h> |
| 19 | #include <linux/file.h> |
| 20 | #include <linux/mount.h> |
| 21 | #include <linux/namei.h> |
| 22 | #include <linux/sysctl.h> |
| 23 | #include <linux/poll.h> |
| 24 | #include <linux/mqueue.h> |
| 25 | #include <linux/msg.h> |
| 26 | #include <linux/skbuff.h> |
| 27 | #include <linux/netlink.h> |
| 28 | #include <linux/syscalls.h> |
George C. Wilson | 20ca73b | 2006-05-24 16:09:55 -0500 | [diff] [blame] | 29 | #include <linux/audit.h> |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 30 | #include <linux/signal.h> |
Ingo Molnar | 5f921ae | 2006-03-26 01:37:17 -0800 | [diff] [blame] | 31 | #include <linux/mutex.h> |
| 32 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | #include <net/sock.h> |
| 34 | #include "util.h" |
| 35 | |
| 36 | #define MQUEUE_MAGIC 0x19800202 |
| 37 | #define DIRENT_SIZE 20 |
| 38 | #define FILENT_SIZE 80 |
| 39 | |
| 40 | #define SEND 0 |
| 41 | #define RECV 1 |
| 42 | |
| 43 | #define STATE_NONE 0 |
| 44 | #define STATE_PENDING 1 |
| 45 | #define STATE_READY 2 |
| 46 | |
| 47 | /* used by sysctl */ |
| 48 | #define FS_MQUEUE 1 |
| 49 | #define CTL_QUEUESMAX 2 |
| 50 | #define CTL_MSGMAX 3 |
| 51 | #define CTL_MSGSIZEMAX 4 |
| 52 | |
| 53 | /* default values */ |
| 54 | #define DFLT_QUEUESMAX 256 /* max number of message queues */ |
| 55 | #define DFLT_MSGMAX 10 /* max number of messages in each queue */ |
| 56 | #define HARD_MSGMAX (131072/sizeof(void*)) |
| 57 | #define DFLT_MSGSIZEMAX 8192 /* max message size */ |
| 58 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | |
| 60 | struct ext_wait_queue { /* queue of sleeping tasks */ |
| 61 | struct task_struct *task; |
| 62 | struct list_head list; |
| 63 | struct msg_msg *msg; /* ptr of loaded message */ |
| 64 | int state; /* one of STATE_* values */ |
| 65 | }; |
| 66 | |
| 67 | struct mqueue_inode_info { |
| 68 | spinlock_t lock; |
| 69 | struct inode vfs_inode; |
| 70 | wait_queue_head_t wait_q; |
| 71 | |
| 72 | struct msg_msg **messages; |
| 73 | struct mq_attr attr; |
| 74 | |
| 75 | struct sigevent notify; |
Cedric Le Goater | a03fcb7 | 2006-10-02 02:17:26 -0700 | [diff] [blame] | 76 | struct pid* notify_owner; |
Adrian Bunk | 338cec3 | 2005-09-10 00:26:54 -0700 | [diff] [blame] | 77 | struct user_struct *user; /* user who created, for accounting */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | struct sock *notify_sock; |
| 79 | struct sk_buff *notify_cookie; |
| 80 | |
| 81 | /* for tasks waiting for free space and messages, respectively */ |
| 82 | struct ext_wait_queue e_wait_q[2]; |
| 83 | |
| 84 | unsigned long qsize; /* size of queue in memory (sum of all msgs) */ |
| 85 | }; |
| 86 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 87 | static const struct inode_operations mqueue_dir_inode_operations; |
Arjan van de Ven | 9a32144 | 2007-02-12 00:55:35 -0800 | [diff] [blame] | 88 | static const struct file_operations mqueue_file_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | static struct super_operations mqueue_super_ops; |
| 90 | static void remove_notification(struct mqueue_inode_info *info); |
| 91 | |
| 92 | static spinlock_t mq_lock; |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 93 | static struct kmem_cache *mqueue_inode_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | static struct vfsmount *mqueue_mnt; |
| 95 | |
| 96 | static unsigned int queues_count; |
| 97 | static unsigned int queues_max = DFLT_QUEUESMAX; |
| 98 | static unsigned int msg_max = DFLT_MSGMAX; |
| 99 | static unsigned int msgsize_max = DFLT_MSGSIZEMAX; |
| 100 | |
| 101 | static struct ctl_table_header * mq_sysctl_table; |
| 102 | |
| 103 | static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode) |
| 104 | { |
| 105 | return container_of(inode, struct mqueue_inode_info, vfs_inode); |
| 106 | } |
| 107 | |
| 108 | static struct inode *mqueue_get_inode(struct super_block *sb, int mode, |
| 109 | struct mq_attr *attr) |
| 110 | { |
| 111 | struct inode *inode; |
| 112 | |
| 113 | inode = new_inode(sb); |
| 114 | if (inode) { |
| 115 | inode->i_mode = mode; |
| 116 | inode->i_uid = current->fsuid; |
| 117 | inode->i_gid = current->fsgid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | inode->i_blocks = 0; |
| 119 | inode->i_mtime = inode->i_ctime = inode->i_atime = |
| 120 | CURRENT_TIME; |
| 121 | |
| 122 | if (S_ISREG(mode)) { |
| 123 | struct mqueue_inode_info *info; |
| 124 | struct task_struct *p = current; |
| 125 | struct user_struct *u = p->user; |
| 126 | unsigned long mq_bytes, mq_msg_tblsz; |
| 127 | |
| 128 | inode->i_fop = &mqueue_file_operations; |
| 129 | inode->i_size = FILENT_SIZE; |
| 130 | /* mqueue specific info */ |
| 131 | info = MQUEUE_I(inode); |
| 132 | spin_lock_init(&info->lock); |
| 133 | init_waitqueue_head(&info->wait_q); |
| 134 | INIT_LIST_HEAD(&info->e_wait_q[0].list); |
| 135 | INIT_LIST_HEAD(&info->e_wait_q[1].list); |
| 136 | info->messages = NULL; |
Cedric Le Goater | a03fcb7 | 2006-10-02 02:17:26 -0700 | [diff] [blame] | 137 | info->notify_owner = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | info->qsize = 0; |
| 139 | info->user = NULL; /* set when all is ok */ |
| 140 | memset(&info->attr, 0, sizeof(info->attr)); |
| 141 | info->attr.mq_maxmsg = DFLT_MSGMAX; |
| 142 | info->attr.mq_msgsize = DFLT_MSGSIZEMAX; |
| 143 | if (attr) { |
| 144 | info->attr.mq_maxmsg = attr->mq_maxmsg; |
| 145 | info->attr.mq_msgsize = attr->mq_msgsize; |
| 146 | } |
| 147 | mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *); |
| 148 | mq_bytes = (mq_msg_tblsz + |
| 149 | (info->attr.mq_maxmsg * info->attr.mq_msgsize)); |
| 150 | |
| 151 | spin_lock(&mq_lock); |
| 152 | if (u->mq_bytes + mq_bytes < u->mq_bytes || |
| 153 | u->mq_bytes + mq_bytes > |
| 154 | p->signal->rlim[RLIMIT_MSGQUEUE].rlim_cur) { |
| 155 | spin_unlock(&mq_lock); |
| 156 | goto out_inode; |
| 157 | } |
| 158 | u->mq_bytes += mq_bytes; |
| 159 | spin_unlock(&mq_lock); |
| 160 | |
| 161 | info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL); |
| 162 | if (!info->messages) { |
| 163 | spin_lock(&mq_lock); |
| 164 | u->mq_bytes -= mq_bytes; |
| 165 | spin_unlock(&mq_lock); |
| 166 | goto out_inode; |
| 167 | } |
| 168 | /* all is ok */ |
| 169 | info->user = get_uid(u); |
| 170 | } else if (S_ISDIR(mode)) { |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 171 | inc_nlink(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 172 | /* Some things misbehave if size == 0 on a directory */ |
| 173 | inode->i_size = 2 * DIRENT_SIZE; |
| 174 | inode->i_op = &mqueue_dir_inode_operations; |
| 175 | inode->i_fop = &simple_dir_operations; |
| 176 | } |
| 177 | } |
| 178 | return inode; |
| 179 | out_inode: |
| 180 | make_bad_inode(inode); |
| 181 | iput(inode); |
| 182 | return NULL; |
| 183 | } |
| 184 | |
| 185 | static int mqueue_fill_super(struct super_block *sb, void *data, int silent) |
| 186 | { |
| 187 | struct inode *inode; |
| 188 | |
| 189 | sb->s_blocksize = PAGE_CACHE_SIZE; |
| 190 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; |
| 191 | sb->s_magic = MQUEUE_MAGIC; |
| 192 | sb->s_op = &mqueue_super_ops; |
| 193 | |
| 194 | inode = mqueue_get_inode(sb, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL); |
| 195 | if (!inode) |
| 196 | return -ENOMEM; |
| 197 | |
| 198 | sb->s_root = d_alloc_root(inode); |
| 199 | if (!sb->s_root) { |
| 200 | iput(inode); |
| 201 | return -ENOMEM; |
| 202 | } |
| 203 | |
| 204 | return 0; |
| 205 | } |
| 206 | |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 207 | static int mqueue_get_sb(struct file_system_type *fs_type, |
| 208 | int flags, const char *dev_name, |
| 209 | void *data, struct vfsmount *mnt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 210 | { |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 211 | return get_sb_single(fs_type, flags, data, mqueue_fill_super, mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | } |
| 213 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 214 | static void init_once(void *foo, struct kmem_cache * cachep, unsigned long flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | { |
| 216 | struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo; |
| 217 | |
Christoph Lameter | 50953fe | 2007-05-06 14:50:16 -0700 | [diff] [blame] | 218 | if (flags & SLAB_CTOR_CONSTRUCTOR) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 219 | inode_init_once(&p->vfs_inode); |
| 220 | } |
| 221 | |
| 222 | static struct inode *mqueue_alloc_inode(struct super_block *sb) |
| 223 | { |
| 224 | struct mqueue_inode_info *ei; |
| 225 | |
Christoph Lameter | e94b176 | 2006-12-06 20:33:17 -0800 | [diff] [blame] | 226 | ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | if (!ei) |
| 228 | return NULL; |
| 229 | return &ei->vfs_inode; |
| 230 | } |
| 231 | |
| 232 | static void mqueue_destroy_inode(struct inode *inode) |
| 233 | { |
| 234 | kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode)); |
| 235 | } |
| 236 | |
| 237 | static void mqueue_delete_inode(struct inode *inode) |
| 238 | { |
| 239 | struct mqueue_inode_info *info; |
| 240 | struct user_struct *user; |
| 241 | unsigned long mq_bytes; |
| 242 | int i; |
| 243 | |
| 244 | if (S_ISDIR(inode->i_mode)) { |
| 245 | clear_inode(inode); |
| 246 | return; |
| 247 | } |
| 248 | info = MQUEUE_I(inode); |
| 249 | spin_lock(&info->lock); |
| 250 | for (i = 0; i < info->attr.mq_curmsgs; i++) |
| 251 | free_msg(info->messages[i]); |
| 252 | kfree(info->messages); |
| 253 | spin_unlock(&info->lock); |
| 254 | |
| 255 | clear_inode(inode); |
| 256 | |
| 257 | mq_bytes = (info->attr.mq_maxmsg * sizeof(struct msg_msg *) + |
| 258 | (info->attr.mq_maxmsg * info->attr.mq_msgsize)); |
| 259 | user = info->user; |
| 260 | if (user) { |
| 261 | spin_lock(&mq_lock); |
| 262 | user->mq_bytes -= mq_bytes; |
| 263 | queues_count--; |
| 264 | spin_unlock(&mq_lock); |
| 265 | free_uid(user); |
| 266 | } |
| 267 | } |
| 268 | |
| 269 | static int mqueue_create(struct inode *dir, struct dentry *dentry, |
| 270 | int mode, struct nameidata *nd) |
| 271 | { |
| 272 | struct inode *inode; |
| 273 | struct mq_attr *attr = dentry->d_fsdata; |
| 274 | int error; |
| 275 | |
| 276 | spin_lock(&mq_lock); |
| 277 | if (queues_count >= queues_max && !capable(CAP_SYS_RESOURCE)) { |
| 278 | error = -ENOSPC; |
| 279 | goto out_lock; |
| 280 | } |
| 281 | queues_count++; |
| 282 | spin_unlock(&mq_lock); |
| 283 | |
| 284 | inode = mqueue_get_inode(dir->i_sb, mode, attr); |
| 285 | if (!inode) { |
| 286 | error = -ENOMEM; |
| 287 | spin_lock(&mq_lock); |
| 288 | queues_count--; |
| 289 | goto out_lock; |
| 290 | } |
| 291 | |
| 292 | dir->i_size += DIRENT_SIZE; |
| 293 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; |
| 294 | |
| 295 | d_instantiate(dentry, inode); |
| 296 | dget(dentry); |
| 297 | return 0; |
| 298 | out_lock: |
| 299 | spin_unlock(&mq_lock); |
| 300 | return error; |
| 301 | } |
| 302 | |
| 303 | static int mqueue_unlink(struct inode *dir, struct dentry *dentry) |
| 304 | { |
| 305 | struct inode *inode = dentry->d_inode; |
| 306 | |
| 307 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; |
| 308 | dir->i_size -= DIRENT_SIZE; |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 309 | drop_nlink(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | dput(dentry); |
| 311 | return 0; |
| 312 | } |
| 313 | |
| 314 | /* |
| 315 | * This is routine for system read from queue file. |
| 316 | * To avoid mess with doing here some sort of mq_receive we allow |
| 317 | * to read only queue size & notification info (the only values |
| 318 | * that are interesting from user point of view and aren't accessible |
| 319 | * through std routines) |
| 320 | */ |
| 321 | static ssize_t mqueue_read_file(struct file *filp, char __user *u_data, |
| 322 | size_t count, loff_t * off) |
| 323 | { |
Josef Sipek | 6d63079 | 2006-12-08 02:37:11 -0800 | [diff] [blame] | 324 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 325 | char buffer[FILENT_SIZE]; |
| 326 | size_t slen; |
| 327 | loff_t o; |
| 328 | |
| 329 | if (!count) |
| 330 | return 0; |
| 331 | |
| 332 | spin_lock(&info->lock); |
| 333 | snprintf(buffer, sizeof(buffer), |
| 334 | "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n", |
| 335 | info->qsize, |
| 336 | info->notify_owner ? info->notify.sigev_notify : 0, |
| 337 | (info->notify_owner && |
| 338 | info->notify.sigev_notify == SIGEV_SIGNAL) ? |
| 339 | info->notify.sigev_signo : 0, |
Cedric Le Goater | a03fcb7 | 2006-10-02 02:17:26 -0700 | [diff] [blame] | 340 | pid_nr(info->notify_owner)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | spin_unlock(&info->lock); |
| 342 | buffer[sizeof(buffer)-1] = '\0'; |
| 343 | slen = strlen(buffer)+1; |
| 344 | |
| 345 | o = *off; |
| 346 | if (o > slen) |
| 347 | return 0; |
| 348 | |
| 349 | if (o + count > slen) |
| 350 | count = slen - o; |
| 351 | |
| 352 | if (copy_to_user(u_data, buffer + o, count)) |
| 353 | return -EFAULT; |
| 354 | |
| 355 | *off = o + count; |
Josef Sipek | 6d63079 | 2006-12-08 02:37:11 -0800 | [diff] [blame] | 356 | filp->f_path.dentry->d_inode->i_atime = filp->f_path.dentry->d_inode->i_ctime = CURRENT_TIME; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 357 | return count; |
| 358 | } |
| 359 | |
Miklos Szeredi | 75e1fcc | 2006-06-23 02:05:12 -0700 | [diff] [blame] | 360 | static int mqueue_flush_file(struct file *filp, fl_owner_t id) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | { |
Josef Sipek | 6d63079 | 2006-12-08 02:37:11 -0800 | [diff] [blame] | 362 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | |
| 364 | spin_lock(&info->lock); |
Cedric Le Goater | a03fcb7 | 2006-10-02 02:17:26 -0700 | [diff] [blame] | 365 | if (task_tgid(current) == info->notify_owner) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 366 | remove_notification(info); |
| 367 | |
| 368 | spin_unlock(&info->lock); |
| 369 | return 0; |
| 370 | } |
| 371 | |
| 372 | static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab) |
| 373 | { |
Josef Sipek | 6d63079 | 2006-12-08 02:37:11 -0800 | [diff] [blame] | 374 | struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | int retval = 0; |
| 376 | |
| 377 | poll_wait(filp, &info->wait_q, poll_tab); |
| 378 | |
| 379 | spin_lock(&info->lock); |
| 380 | if (info->attr.mq_curmsgs) |
| 381 | retval = POLLIN | POLLRDNORM; |
| 382 | |
| 383 | if (info->attr.mq_curmsgs < info->attr.mq_maxmsg) |
| 384 | retval |= POLLOUT | POLLWRNORM; |
| 385 | spin_unlock(&info->lock); |
| 386 | |
| 387 | return retval; |
| 388 | } |
| 389 | |
| 390 | /* Adds current to info->e_wait_q[sr] before element with smaller prio */ |
| 391 | static void wq_add(struct mqueue_inode_info *info, int sr, |
| 392 | struct ext_wait_queue *ewp) |
| 393 | { |
| 394 | struct ext_wait_queue *walk; |
| 395 | |
| 396 | ewp->task = current; |
| 397 | |
| 398 | list_for_each_entry(walk, &info->e_wait_q[sr].list, list) { |
| 399 | if (walk->task->static_prio <= current->static_prio) { |
| 400 | list_add_tail(&ewp->list, &walk->list); |
| 401 | return; |
| 402 | } |
| 403 | } |
| 404 | list_add_tail(&ewp->list, &info->e_wait_q[sr].list); |
| 405 | } |
| 406 | |
| 407 | /* |
| 408 | * Puts current task to sleep. Caller must hold queue lock. After return |
| 409 | * lock isn't held. |
| 410 | * sr: SEND or RECV |
| 411 | */ |
| 412 | static int wq_sleep(struct mqueue_inode_info *info, int sr, |
| 413 | long timeout, struct ext_wait_queue *ewp) |
| 414 | { |
| 415 | int retval; |
| 416 | signed long time; |
| 417 | |
| 418 | wq_add(info, sr, ewp); |
| 419 | |
| 420 | for (;;) { |
| 421 | set_current_state(TASK_INTERRUPTIBLE); |
| 422 | |
| 423 | spin_unlock(&info->lock); |
| 424 | time = schedule_timeout(timeout); |
| 425 | |
| 426 | while (ewp->state == STATE_PENDING) |
| 427 | cpu_relax(); |
| 428 | |
| 429 | if (ewp->state == STATE_READY) { |
| 430 | retval = 0; |
| 431 | goto out; |
| 432 | } |
| 433 | spin_lock(&info->lock); |
| 434 | if (ewp->state == STATE_READY) { |
| 435 | retval = 0; |
| 436 | goto out_unlock; |
| 437 | } |
| 438 | if (signal_pending(current)) { |
| 439 | retval = -ERESTARTSYS; |
| 440 | break; |
| 441 | } |
| 442 | if (time == 0) { |
| 443 | retval = -ETIMEDOUT; |
| 444 | break; |
| 445 | } |
| 446 | } |
| 447 | list_del(&ewp->list); |
| 448 | out_unlock: |
| 449 | spin_unlock(&info->lock); |
| 450 | out: |
| 451 | return retval; |
| 452 | } |
| 453 | |
| 454 | /* |
| 455 | * Returns waiting task that should be serviced first or NULL if none exists |
| 456 | */ |
| 457 | static struct ext_wait_queue *wq_get_first_waiter( |
| 458 | struct mqueue_inode_info *info, int sr) |
| 459 | { |
| 460 | struct list_head *ptr; |
| 461 | |
| 462 | ptr = info->e_wait_q[sr].list.prev; |
| 463 | if (ptr == &info->e_wait_q[sr].list) |
| 464 | return NULL; |
| 465 | return list_entry(ptr, struct ext_wait_queue, list); |
| 466 | } |
| 467 | |
| 468 | /* Auxiliary functions to manipulate messages' list */ |
| 469 | static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info) |
| 470 | { |
| 471 | int k; |
| 472 | |
| 473 | k = info->attr.mq_curmsgs - 1; |
| 474 | while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) { |
| 475 | info->messages[k + 1] = info->messages[k]; |
| 476 | k--; |
| 477 | } |
| 478 | info->attr.mq_curmsgs++; |
| 479 | info->qsize += ptr->m_ts; |
| 480 | info->messages[k + 1] = ptr; |
| 481 | } |
| 482 | |
| 483 | static inline struct msg_msg *msg_get(struct mqueue_inode_info *info) |
| 484 | { |
| 485 | info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts; |
| 486 | return info->messages[info->attr.mq_curmsgs]; |
| 487 | } |
| 488 | |
| 489 | static inline void set_cookie(struct sk_buff *skb, char code) |
| 490 | { |
| 491 | ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code; |
| 492 | } |
| 493 | |
| 494 | /* |
| 495 | * The next function is only to split too long sys_mq_timedsend |
| 496 | */ |
| 497 | static void __do_notify(struct mqueue_inode_info *info) |
| 498 | { |
| 499 | /* notification |
| 500 | * invoked when there is registered process and there isn't process |
| 501 | * waiting synchronously for message AND state of queue changed from |
| 502 | * empty to not empty. Here we are sure that no one is waiting |
| 503 | * synchronously. */ |
| 504 | if (info->notify_owner && |
| 505 | info->attr.mq_curmsgs == 1) { |
| 506 | struct siginfo sig_i; |
| 507 | switch (info->notify.sigev_notify) { |
| 508 | case SIGEV_NONE: |
| 509 | break; |
| 510 | case SIGEV_SIGNAL: |
| 511 | /* sends signal */ |
| 512 | |
| 513 | sig_i.si_signo = info->notify.sigev_signo; |
| 514 | sig_i.si_errno = 0; |
| 515 | sig_i.si_code = SI_MESGQ; |
| 516 | sig_i.si_value = info->notify.sigev_value; |
| 517 | sig_i.si_pid = current->tgid; |
| 518 | sig_i.si_uid = current->uid; |
| 519 | |
Cedric Le Goater | a03fcb7 | 2006-10-02 02:17:26 -0700 | [diff] [blame] | 520 | kill_pid_info(info->notify.sigev_signo, |
| 521 | &sig_i, info->notify_owner); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 522 | break; |
| 523 | case SIGEV_THREAD: |
| 524 | set_cookie(info->notify_cookie, NOTIFY_WOKENUP); |
| 525 | netlink_sendskb(info->notify_sock, |
| 526 | info->notify_cookie, 0); |
| 527 | break; |
| 528 | } |
| 529 | /* after notification unregisters process */ |
Cedric Le Goater | a03fcb7 | 2006-10-02 02:17:26 -0700 | [diff] [blame] | 530 | put_pid(info->notify_owner); |
| 531 | info->notify_owner = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | } |
| 533 | wake_up(&info->wait_q); |
| 534 | } |
| 535 | |
| 536 | static long prepare_timeout(const struct timespec __user *u_arg) |
| 537 | { |
| 538 | struct timespec ts, nowts; |
| 539 | long timeout; |
| 540 | |
| 541 | if (u_arg) { |
| 542 | if (unlikely(copy_from_user(&ts, u_arg, |
| 543 | sizeof(struct timespec)))) |
| 544 | return -EFAULT; |
| 545 | |
| 546 | if (unlikely(ts.tv_nsec < 0 || ts.tv_sec < 0 |
| 547 | || ts.tv_nsec >= NSEC_PER_SEC)) |
| 548 | return -EINVAL; |
| 549 | nowts = CURRENT_TIME; |
| 550 | /* first subtract as jiffies can't be too big */ |
| 551 | ts.tv_sec -= nowts.tv_sec; |
| 552 | if (ts.tv_nsec < nowts.tv_nsec) { |
| 553 | ts.tv_nsec += NSEC_PER_SEC; |
| 554 | ts.tv_sec--; |
| 555 | } |
| 556 | ts.tv_nsec -= nowts.tv_nsec; |
| 557 | if (ts.tv_sec < 0) |
| 558 | return 0; |
| 559 | |
| 560 | timeout = timespec_to_jiffies(&ts) + 1; |
| 561 | } else |
| 562 | return MAX_SCHEDULE_TIMEOUT; |
| 563 | |
| 564 | return timeout; |
| 565 | } |
| 566 | |
| 567 | static void remove_notification(struct mqueue_inode_info *info) |
| 568 | { |
Cedric Le Goater | a03fcb7 | 2006-10-02 02:17:26 -0700 | [diff] [blame] | 569 | if (info->notify_owner != NULL && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | info->notify.sigev_notify == SIGEV_THREAD) { |
| 571 | set_cookie(info->notify_cookie, NOTIFY_REMOVED); |
| 572 | netlink_sendskb(info->notify_sock, info->notify_cookie, 0); |
| 573 | } |
Cedric Le Goater | a03fcb7 | 2006-10-02 02:17:26 -0700 | [diff] [blame] | 574 | put_pid(info->notify_owner); |
| 575 | info->notify_owner = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 576 | } |
| 577 | |
| 578 | static int mq_attr_ok(struct mq_attr *attr) |
| 579 | { |
| 580 | if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0) |
| 581 | return 0; |
| 582 | if (capable(CAP_SYS_RESOURCE)) { |
| 583 | if (attr->mq_maxmsg > HARD_MSGMAX) |
| 584 | return 0; |
| 585 | } else { |
| 586 | if (attr->mq_maxmsg > msg_max || |
| 587 | attr->mq_msgsize > msgsize_max) |
| 588 | return 0; |
| 589 | } |
| 590 | /* check for overflow */ |
| 591 | if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg) |
| 592 | return 0; |
| 593 | if ((unsigned long)(attr->mq_maxmsg * attr->mq_msgsize) + |
| 594 | (attr->mq_maxmsg * sizeof (struct msg_msg *)) < |
| 595 | (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize)) |
| 596 | return 0; |
| 597 | return 1; |
| 598 | } |
| 599 | |
| 600 | /* |
| 601 | * Invoked when creating a new queue via sys_mq_open |
| 602 | */ |
| 603 | static struct file *do_create(struct dentry *dir, struct dentry *dentry, |
| 604 | int oflag, mode_t mode, struct mq_attr __user *u_attr) |
| 605 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 606 | struct mq_attr attr; |
| 607 | int ret; |
| 608 | |
Alexander Viro | 7c7dce9 | 2006-01-14 15:29:55 -0500 | [diff] [blame] | 609 | if (u_attr) { |
| 610 | ret = -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 611 | if (copy_from_user(&attr, u_attr, sizeof(attr))) |
Alexander Viro | 7c7dce9 | 2006-01-14 15:29:55 -0500 | [diff] [blame] | 612 | goto out; |
| 613 | ret = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 614 | if (!mq_attr_ok(&attr)) |
Alexander Viro | 7c7dce9 | 2006-01-14 15:29:55 -0500 | [diff] [blame] | 615 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 616 | /* store for use during create */ |
| 617 | dentry->d_fsdata = &attr; |
| 618 | } |
| 619 | |
Krzysztof Benedyczak | 5917583 | 2005-09-27 22:21:36 +0200 | [diff] [blame] | 620 | mode &= ~current->fs->umask; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 621 | ret = vfs_create(dir->d_inode, dentry, mode, NULL); |
| 622 | dentry->d_fsdata = NULL; |
| 623 | if (ret) |
Alexander Viro | 7c7dce9 | 2006-01-14 15:29:55 -0500 | [diff] [blame] | 624 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 625 | |
Alexander Viro | 7c7dce9 | 2006-01-14 15:29:55 -0500 | [diff] [blame] | 626 | return dentry_open(dentry, mqueue_mnt, oflag); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 627 | |
Alexander Viro | 7c7dce9 | 2006-01-14 15:29:55 -0500 | [diff] [blame] | 628 | out: |
| 629 | dput(dentry); |
| 630 | mntput(mqueue_mnt); |
| 631 | return ERR_PTR(ret); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 632 | } |
| 633 | |
| 634 | /* Opens existing queue */ |
| 635 | static struct file *do_open(struct dentry *dentry, int oflag) |
| 636 | { |
| 637 | static int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, |
| 638 | MAY_READ | MAY_WRITE }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 639 | |
Alexander Viro | 7c7dce9 | 2006-01-14 15:29:55 -0500 | [diff] [blame] | 640 | if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) { |
| 641 | dput(dentry); |
| 642 | mntput(mqueue_mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 643 | return ERR_PTR(-EINVAL); |
Alexander Viro | 7c7dce9 | 2006-01-14 15:29:55 -0500 | [diff] [blame] | 644 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 645 | |
Alexander Viro | 7c7dce9 | 2006-01-14 15:29:55 -0500 | [diff] [blame] | 646 | if (permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE], NULL)) { |
| 647 | dput(dentry); |
| 648 | mntput(mqueue_mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 649 | return ERR_PTR(-EACCES); |
Alexander Viro | 7c7dce9 | 2006-01-14 15:29:55 -0500 | [diff] [blame] | 650 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 651 | |
Alexander Viro | 7c7dce9 | 2006-01-14 15:29:55 -0500 | [diff] [blame] | 652 | return dentry_open(dentry, mqueue_mnt, oflag); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 653 | } |
| 654 | |
| 655 | asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode, |
| 656 | struct mq_attr __user *u_attr) |
| 657 | { |
| 658 | struct dentry *dentry; |
| 659 | struct file *filp; |
| 660 | char *name; |
| 661 | int fd, error; |
| 662 | |
George C. Wilson | 20ca73b | 2006-05-24 16:09:55 -0500 | [diff] [blame] | 663 | error = audit_mq_open(oflag, mode, u_attr); |
| 664 | if (error != 0) |
| 665 | return error; |
| 666 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 667 | if (IS_ERR(name = getname(u_name))) |
| 668 | return PTR_ERR(name); |
| 669 | |
| 670 | fd = get_unused_fd(); |
| 671 | if (fd < 0) |
| 672 | goto out_putname; |
| 673 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 674 | mutex_lock(&mqueue_mnt->mnt_root->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 675 | dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name)); |
| 676 | if (IS_ERR(dentry)) { |
| 677 | error = PTR_ERR(dentry); |
| 678 | goto out_err; |
| 679 | } |
| 680 | mntget(mqueue_mnt); |
| 681 | |
| 682 | if (oflag & O_CREAT) { |
| 683 | if (dentry->d_inode) { /* entry already exists */ |
Alexander Viro | 7c7dce9 | 2006-01-14 15:29:55 -0500 | [diff] [blame] | 684 | error = -EEXIST; |
| 685 | if (oflag & O_EXCL) |
| 686 | goto out; |
| 687 | filp = do_open(dentry, oflag); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 688 | } else { |
| 689 | filp = do_create(mqueue_mnt->mnt_root, dentry, |
| 690 | oflag, mode, u_attr); |
| 691 | } |
Alexander Viro | 7c7dce9 | 2006-01-14 15:29:55 -0500 | [diff] [blame] | 692 | } else { |
| 693 | error = -ENOENT; |
| 694 | if (!dentry->d_inode) |
| 695 | goto out; |
| 696 | filp = do_open(dentry, oflag); |
| 697 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | |
| 699 | if (IS_ERR(filp)) { |
| 700 | error = PTR_ERR(filp); |
| 701 | goto out_putfd; |
| 702 | } |
| 703 | |
| 704 | set_close_on_exec(fd, 1); |
| 705 | fd_install(fd, filp); |
| 706 | goto out_upsem; |
| 707 | |
Alexander Viro | 7c7dce9 | 2006-01-14 15:29:55 -0500 | [diff] [blame] | 708 | out: |
| 709 | dput(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 710 | mntput(mqueue_mnt); |
Alexander Viro | 7c7dce9 | 2006-01-14 15:29:55 -0500 | [diff] [blame] | 711 | out_putfd: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 712 | put_unused_fd(fd); |
| 713 | out_err: |
| 714 | fd = error; |
| 715 | out_upsem: |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 716 | mutex_unlock(&mqueue_mnt->mnt_root->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | out_putname: |
| 718 | putname(name); |
| 719 | return fd; |
| 720 | } |
| 721 | |
| 722 | asmlinkage long sys_mq_unlink(const char __user *u_name) |
| 723 | { |
| 724 | int err; |
| 725 | char *name; |
| 726 | struct dentry *dentry; |
| 727 | struct inode *inode = NULL; |
| 728 | |
| 729 | name = getname(u_name); |
| 730 | if (IS_ERR(name)) |
| 731 | return PTR_ERR(name); |
| 732 | |
Peter Zijlstra | 7a43481 | 2007-03-06 01:42:09 -0800 | [diff] [blame] | 733 | mutex_lock_nested(&mqueue_mnt->mnt_root->d_inode->i_mutex, |
| 734 | I_MUTEX_PARENT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 735 | dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name)); |
| 736 | if (IS_ERR(dentry)) { |
| 737 | err = PTR_ERR(dentry); |
| 738 | goto out_unlock; |
| 739 | } |
| 740 | |
| 741 | if (!dentry->d_inode) { |
| 742 | err = -ENOENT; |
| 743 | goto out_err; |
| 744 | } |
| 745 | |
| 746 | inode = dentry->d_inode; |
| 747 | if (inode) |
| 748 | atomic_inc(&inode->i_count); |
| 749 | |
| 750 | err = vfs_unlink(dentry->d_parent->d_inode, dentry); |
| 751 | out_err: |
| 752 | dput(dentry); |
| 753 | |
| 754 | out_unlock: |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 755 | mutex_unlock(&mqueue_mnt->mnt_root->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 756 | putname(name); |
| 757 | if (inode) |
| 758 | iput(inode); |
| 759 | |
| 760 | return err; |
| 761 | } |
| 762 | |
| 763 | /* Pipelined send and receive functions. |
| 764 | * |
| 765 | * If a receiver finds no waiting message, then it registers itself in the |
| 766 | * list of waiting receivers. A sender checks that list before adding the new |
| 767 | * message into the message array. If there is a waiting receiver, then it |
| 768 | * bypasses the message array and directly hands the message over to the |
| 769 | * receiver. |
| 770 | * The receiver accepts the message and returns without grabbing the queue |
| 771 | * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers |
| 772 | * are necessary. The same algorithm is used for sysv semaphores, see |
Serge E. Hallyn | 7b7a317 | 2006-03-28 01:56:23 -0800 | [diff] [blame] | 773 | * ipc/sem.c for more details. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 774 | * |
| 775 | * The same algorithm is used for senders. |
| 776 | */ |
| 777 | |
| 778 | /* pipelined_send() - send a message directly to the task waiting in |
| 779 | * sys_mq_timedreceive() (without inserting message into a queue). |
| 780 | */ |
| 781 | static inline void pipelined_send(struct mqueue_inode_info *info, |
| 782 | struct msg_msg *message, |
| 783 | struct ext_wait_queue *receiver) |
| 784 | { |
| 785 | receiver->msg = message; |
| 786 | list_del(&receiver->list); |
| 787 | receiver->state = STATE_PENDING; |
| 788 | wake_up_process(receiver->task); |
akpm@osdl.org | d59dd46 | 2005-05-01 08:58:47 -0700 | [diff] [blame] | 789 | smp_wmb(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 790 | receiver->state = STATE_READY; |
| 791 | } |
| 792 | |
| 793 | /* pipelined_receive() - if there is task waiting in sys_mq_timedsend() |
| 794 | * gets its message and put to the queue (we have one free place for sure). */ |
| 795 | static inline void pipelined_receive(struct mqueue_inode_info *info) |
| 796 | { |
| 797 | struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND); |
| 798 | |
| 799 | if (!sender) { |
| 800 | /* for poll */ |
| 801 | wake_up_interruptible(&info->wait_q); |
| 802 | return; |
| 803 | } |
| 804 | msg_insert(sender->msg, info); |
| 805 | list_del(&sender->list); |
| 806 | sender->state = STATE_PENDING; |
| 807 | wake_up_process(sender->task); |
akpm@osdl.org | d59dd46 | 2005-05-01 08:58:47 -0700 | [diff] [blame] | 808 | smp_wmb(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 809 | sender->state = STATE_READY; |
| 810 | } |
| 811 | |
| 812 | asmlinkage long sys_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr, |
| 813 | size_t msg_len, unsigned int msg_prio, |
| 814 | const struct timespec __user *u_abs_timeout) |
| 815 | { |
| 816 | struct file *filp; |
| 817 | struct inode *inode; |
| 818 | struct ext_wait_queue wait; |
| 819 | struct ext_wait_queue *receiver; |
| 820 | struct msg_msg *msg_ptr; |
| 821 | struct mqueue_inode_info *info; |
| 822 | long timeout; |
| 823 | int ret; |
| 824 | |
George C. Wilson | 20ca73b | 2006-05-24 16:09:55 -0500 | [diff] [blame] | 825 | ret = audit_mq_timedsend(mqdes, msg_len, msg_prio, u_abs_timeout); |
| 826 | if (ret != 0) |
| 827 | return ret; |
| 828 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 829 | if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX)) |
| 830 | return -EINVAL; |
| 831 | |
| 832 | timeout = prepare_timeout(u_abs_timeout); |
| 833 | |
| 834 | ret = -EBADF; |
| 835 | filp = fget(mqdes); |
| 836 | if (unlikely(!filp)) |
| 837 | goto out; |
| 838 | |
Josef Sipek | 6d63079 | 2006-12-08 02:37:11 -0800 | [diff] [blame] | 839 | inode = filp->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 840 | if (unlikely(filp->f_op != &mqueue_file_operations)) |
| 841 | goto out_fput; |
| 842 | info = MQUEUE_I(inode); |
| 843 | |
| 844 | if (unlikely(!(filp->f_mode & FMODE_WRITE))) |
| 845 | goto out_fput; |
| 846 | |
| 847 | if (unlikely(msg_len > info->attr.mq_msgsize)) { |
| 848 | ret = -EMSGSIZE; |
| 849 | goto out_fput; |
| 850 | } |
| 851 | |
| 852 | /* First try to allocate memory, before doing anything with |
| 853 | * existing queues. */ |
| 854 | msg_ptr = load_msg(u_msg_ptr, msg_len); |
| 855 | if (IS_ERR(msg_ptr)) { |
| 856 | ret = PTR_ERR(msg_ptr); |
| 857 | goto out_fput; |
| 858 | } |
| 859 | msg_ptr->m_ts = msg_len; |
| 860 | msg_ptr->m_type = msg_prio; |
| 861 | |
| 862 | spin_lock(&info->lock); |
| 863 | |
| 864 | if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) { |
| 865 | if (filp->f_flags & O_NONBLOCK) { |
| 866 | spin_unlock(&info->lock); |
| 867 | ret = -EAGAIN; |
| 868 | } else if (unlikely(timeout < 0)) { |
| 869 | spin_unlock(&info->lock); |
| 870 | ret = timeout; |
| 871 | } else { |
| 872 | wait.task = current; |
| 873 | wait.msg = (void *) msg_ptr; |
| 874 | wait.state = STATE_NONE; |
| 875 | ret = wq_sleep(info, SEND, timeout, &wait); |
| 876 | } |
| 877 | if (ret < 0) |
| 878 | free_msg(msg_ptr); |
| 879 | } else { |
| 880 | receiver = wq_get_first_waiter(info, RECV); |
| 881 | if (receiver) { |
| 882 | pipelined_send(info, msg_ptr, receiver); |
| 883 | } else { |
| 884 | /* adds message to the queue */ |
| 885 | msg_insert(msg_ptr, info); |
| 886 | __do_notify(info); |
| 887 | } |
| 888 | inode->i_atime = inode->i_mtime = inode->i_ctime = |
| 889 | CURRENT_TIME; |
| 890 | spin_unlock(&info->lock); |
| 891 | ret = 0; |
| 892 | } |
| 893 | out_fput: |
| 894 | fput(filp); |
| 895 | out: |
| 896 | return ret; |
| 897 | } |
| 898 | |
| 899 | asmlinkage ssize_t sys_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr, |
| 900 | size_t msg_len, unsigned int __user *u_msg_prio, |
| 901 | const struct timespec __user *u_abs_timeout) |
| 902 | { |
| 903 | long timeout; |
| 904 | ssize_t ret; |
| 905 | struct msg_msg *msg_ptr; |
| 906 | struct file *filp; |
| 907 | struct inode *inode; |
| 908 | struct mqueue_inode_info *info; |
| 909 | struct ext_wait_queue wait; |
| 910 | |
George C. Wilson | 20ca73b | 2006-05-24 16:09:55 -0500 | [diff] [blame] | 911 | ret = audit_mq_timedreceive(mqdes, msg_len, u_msg_prio, u_abs_timeout); |
| 912 | if (ret != 0) |
| 913 | return ret; |
| 914 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 915 | timeout = prepare_timeout(u_abs_timeout); |
| 916 | |
| 917 | ret = -EBADF; |
| 918 | filp = fget(mqdes); |
| 919 | if (unlikely(!filp)) |
| 920 | goto out; |
| 921 | |
Josef Sipek | 6d63079 | 2006-12-08 02:37:11 -0800 | [diff] [blame] | 922 | inode = filp->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 923 | if (unlikely(filp->f_op != &mqueue_file_operations)) |
| 924 | goto out_fput; |
| 925 | info = MQUEUE_I(inode); |
| 926 | |
| 927 | if (unlikely(!(filp->f_mode & FMODE_READ))) |
| 928 | goto out_fput; |
| 929 | |
| 930 | /* checks if buffer is big enough */ |
| 931 | if (unlikely(msg_len < info->attr.mq_msgsize)) { |
| 932 | ret = -EMSGSIZE; |
| 933 | goto out_fput; |
| 934 | } |
| 935 | |
| 936 | spin_lock(&info->lock); |
| 937 | if (info->attr.mq_curmsgs == 0) { |
| 938 | if (filp->f_flags & O_NONBLOCK) { |
| 939 | spin_unlock(&info->lock); |
| 940 | ret = -EAGAIN; |
| 941 | msg_ptr = NULL; |
| 942 | } else if (unlikely(timeout < 0)) { |
| 943 | spin_unlock(&info->lock); |
| 944 | ret = timeout; |
| 945 | msg_ptr = NULL; |
| 946 | } else { |
| 947 | wait.task = current; |
| 948 | wait.state = STATE_NONE; |
| 949 | ret = wq_sleep(info, RECV, timeout, &wait); |
| 950 | msg_ptr = wait.msg; |
| 951 | } |
| 952 | } else { |
| 953 | msg_ptr = msg_get(info); |
| 954 | |
| 955 | inode->i_atime = inode->i_mtime = inode->i_ctime = |
| 956 | CURRENT_TIME; |
| 957 | |
| 958 | /* There is now free space in queue. */ |
| 959 | pipelined_receive(info); |
| 960 | spin_unlock(&info->lock); |
| 961 | ret = 0; |
| 962 | } |
| 963 | if (ret == 0) { |
| 964 | ret = msg_ptr->m_ts; |
| 965 | |
| 966 | if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) || |
| 967 | store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) { |
| 968 | ret = -EFAULT; |
| 969 | } |
| 970 | free_msg(msg_ptr); |
| 971 | } |
| 972 | out_fput: |
| 973 | fput(filp); |
| 974 | out: |
| 975 | return ret; |
| 976 | } |
| 977 | |
| 978 | /* |
| 979 | * Notes: the case when user wants us to deregister (with NULL as pointer) |
| 980 | * and he isn't currently owner of notification, will be silently discarded. |
| 981 | * It isn't explicitly defined in the POSIX. |
| 982 | */ |
| 983 | asmlinkage long sys_mq_notify(mqd_t mqdes, |
| 984 | const struct sigevent __user *u_notification) |
| 985 | { |
| 986 | int ret; |
| 987 | struct file *filp; |
| 988 | struct sock *sock; |
| 989 | struct inode *inode; |
| 990 | struct sigevent notification; |
| 991 | struct mqueue_inode_info *info; |
| 992 | struct sk_buff *nc; |
| 993 | |
George C. Wilson | 20ca73b | 2006-05-24 16:09:55 -0500 | [diff] [blame] | 994 | ret = audit_mq_notify(mqdes, u_notification); |
| 995 | if (ret != 0) |
| 996 | return ret; |
| 997 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 998 | nc = NULL; |
| 999 | sock = NULL; |
| 1000 | if (u_notification != NULL) { |
| 1001 | if (copy_from_user(¬ification, u_notification, |
| 1002 | sizeof(struct sigevent))) |
| 1003 | return -EFAULT; |
| 1004 | |
| 1005 | if (unlikely(notification.sigev_notify != SIGEV_NONE && |
| 1006 | notification.sigev_notify != SIGEV_SIGNAL && |
| 1007 | notification.sigev_notify != SIGEV_THREAD)) |
| 1008 | return -EINVAL; |
| 1009 | if (notification.sigev_notify == SIGEV_SIGNAL && |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 1010 | !valid_signal(notification.sigev_signo)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1011 | return -EINVAL; |
| 1012 | } |
| 1013 | if (notification.sigev_notify == SIGEV_THREAD) { |
| 1014 | /* create the notify skb */ |
| 1015 | nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL); |
| 1016 | ret = -ENOMEM; |
| 1017 | if (!nc) |
| 1018 | goto out; |
| 1019 | ret = -EFAULT; |
| 1020 | if (copy_from_user(nc->data, |
| 1021 | notification.sigev_value.sival_ptr, |
| 1022 | NOTIFY_COOKIE_LEN)) { |
| 1023 | goto out; |
| 1024 | } |
| 1025 | |
| 1026 | /* TODO: add a header? */ |
| 1027 | skb_put(nc, NOTIFY_COOKIE_LEN); |
| 1028 | /* and attach it to the socket */ |
| 1029 | retry: |
| 1030 | filp = fget(notification.sigev_signo); |
| 1031 | ret = -EBADF; |
| 1032 | if (!filp) |
| 1033 | goto out; |
| 1034 | sock = netlink_getsockbyfilp(filp); |
| 1035 | fput(filp); |
| 1036 | if (IS_ERR(sock)) { |
| 1037 | ret = PTR_ERR(sock); |
| 1038 | sock = NULL; |
| 1039 | goto out; |
| 1040 | } |
| 1041 | |
Alexey Kuznetsov | a70ea99 | 2006-02-09 16:40:11 -0800 | [diff] [blame] | 1042 | ret = netlink_attachskb(sock, nc, 0, |
| 1043 | MAX_SCHEDULE_TIMEOUT, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1044 | if (ret == 1) |
| 1045 | goto retry; |
| 1046 | if (ret) { |
| 1047 | sock = NULL; |
| 1048 | nc = NULL; |
| 1049 | goto out; |
| 1050 | } |
| 1051 | } |
| 1052 | } |
| 1053 | |
| 1054 | ret = -EBADF; |
| 1055 | filp = fget(mqdes); |
| 1056 | if (!filp) |
| 1057 | goto out; |
| 1058 | |
Josef Sipek | 6d63079 | 2006-12-08 02:37:11 -0800 | [diff] [blame] | 1059 | inode = filp->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1060 | if (unlikely(filp->f_op != &mqueue_file_operations)) |
| 1061 | goto out_fput; |
| 1062 | info = MQUEUE_I(inode); |
| 1063 | |
| 1064 | ret = 0; |
| 1065 | spin_lock(&info->lock); |
| 1066 | if (u_notification == NULL) { |
Cedric Le Goater | a03fcb7 | 2006-10-02 02:17:26 -0700 | [diff] [blame] | 1067 | if (info->notify_owner == task_tgid(current)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1068 | remove_notification(info); |
| 1069 | inode->i_atime = inode->i_ctime = CURRENT_TIME; |
| 1070 | } |
Cedric Le Goater | a03fcb7 | 2006-10-02 02:17:26 -0700 | [diff] [blame] | 1071 | } else if (info->notify_owner != NULL) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1072 | ret = -EBUSY; |
| 1073 | } else { |
| 1074 | switch (notification.sigev_notify) { |
| 1075 | case SIGEV_NONE: |
| 1076 | info->notify.sigev_notify = SIGEV_NONE; |
| 1077 | break; |
| 1078 | case SIGEV_THREAD: |
| 1079 | info->notify_sock = sock; |
| 1080 | info->notify_cookie = nc; |
| 1081 | sock = NULL; |
| 1082 | nc = NULL; |
| 1083 | info->notify.sigev_notify = SIGEV_THREAD; |
| 1084 | break; |
| 1085 | case SIGEV_SIGNAL: |
| 1086 | info->notify.sigev_signo = notification.sigev_signo; |
| 1087 | info->notify.sigev_value = notification.sigev_value; |
| 1088 | info->notify.sigev_notify = SIGEV_SIGNAL; |
| 1089 | break; |
| 1090 | } |
Cedric Le Goater | a03fcb7 | 2006-10-02 02:17:26 -0700 | [diff] [blame] | 1091 | |
| 1092 | info->notify_owner = get_pid(task_tgid(current)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1093 | inode->i_atime = inode->i_ctime = CURRENT_TIME; |
| 1094 | } |
| 1095 | spin_unlock(&info->lock); |
| 1096 | out_fput: |
| 1097 | fput(filp); |
| 1098 | out: |
| 1099 | if (sock) { |
| 1100 | netlink_detachskb(sock, nc); |
| 1101 | } else if (nc) { |
| 1102 | dev_kfree_skb(nc); |
| 1103 | } |
| 1104 | return ret; |
| 1105 | } |
| 1106 | |
| 1107 | asmlinkage long sys_mq_getsetattr(mqd_t mqdes, |
| 1108 | const struct mq_attr __user *u_mqstat, |
| 1109 | struct mq_attr __user *u_omqstat) |
| 1110 | { |
| 1111 | int ret; |
| 1112 | struct mq_attr mqstat, omqstat; |
| 1113 | struct file *filp; |
| 1114 | struct inode *inode; |
| 1115 | struct mqueue_inode_info *info; |
| 1116 | |
| 1117 | if (u_mqstat != NULL) { |
| 1118 | if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr))) |
| 1119 | return -EFAULT; |
| 1120 | if (mqstat.mq_flags & (~O_NONBLOCK)) |
| 1121 | return -EINVAL; |
| 1122 | } |
| 1123 | |
| 1124 | ret = -EBADF; |
| 1125 | filp = fget(mqdes); |
| 1126 | if (!filp) |
| 1127 | goto out; |
| 1128 | |
Josef Sipek | 6d63079 | 2006-12-08 02:37:11 -0800 | [diff] [blame] | 1129 | inode = filp->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1130 | if (unlikely(filp->f_op != &mqueue_file_operations)) |
| 1131 | goto out_fput; |
| 1132 | info = MQUEUE_I(inode); |
| 1133 | |
| 1134 | spin_lock(&info->lock); |
| 1135 | |
| 1136 | omqstat = info->attr; |
| 1137 | omqstat.mq_flags = filp->f_flags & O_NONBLOCK; |
| 1138 | if (u_mqstat) { |
George C. Wilson | 20ca73b | 2006-05-24 16:09:55 -0500 | [diff] [blame] | 1139 | ret = audit_mq_getsetattr(mqdes, &mqstat); |
| 1140 | if (ret != 0) |
| 1141 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1142 | if (mqstat.mq_flags & O_NONBLOCK) |
| 1143 | filp->f_flags |= O_NONBLOCK; |
| 1144 | else |
| 1145 | filp->f_flags &= ~O_NONBLOCK; |
| 1146 | |
| 1147 | inode->i_atime = inode->i_ctime = CURRENT_TIME; |
| 1148 | } |
| 1149 | |
| 1150 | spin_unlock(&info->lock); |
| 1151 | |
| 1152 | ret = 0; |
| 1153 | if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat, |
| 1154 | sizeof(struct mq_attr))) |
| 1155 | ret = -EFAULT; |
| 1156 | |
| 1157 | out_fput: |
| 1158 | fput(filp); |
| 1159 | out: |
| 1160 | return ret; |
| 1161 | } |
| 1162 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 1163 | static const struct inode_operations mqueue_dir_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1164 | .lookup = simple_lookup, |
| 1165 | .create = mqueue_create, |
| 1166 | .unlink = mqueue_unlink, |
| 1167 | }; |
| 1168 | |
Arjan van de Ven | 9a32144 | 2007-02-12 00:55:35 -0800 | [diff] [blame] | 1169 | static const struct file_operations mqueue_file_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1170 | .flush = mqueue_flush_file, |
| 1171 | .poll = mqueue_poll_file, |
| 1172 | .read = mqueue_read_file, |
| 1173 | }; |
| 1174 | |
| 1175 | static struct super_operations mqueue_super_ops = { |
| 1176 | .alloc_inode = mqueue_alloc_inode, |
| 1177 | .destroy_inode = mqueue_destroy_inode, |
| 1178 | .statfs = simple_statfs, |
| 1179 | .delete_inode = mqueue_delete_inode, |
| 1180 | .drop_inode = generic_delete_inode, |
| 1181 | }; |
| 1182 | |
| 1183 | static struct file_system_type mqueue_fs_type = { |
| 1184 | .name = "mqueue", |
| 1185 | .get_sb = mqueue_get_sb, |
| 1186 | .kill_sb = kill_litter_super, |
| 1187 | }; |
| 1188 | |
| 1189 | static int msg_max_limit_min = DFLT_MSGMAX; |
| 1190 | static int msg_max_limit_max = HARD_MSGMAX; |
| 1191 | |
| 1192 | static int msg_maxsize_limit_min = DFLT_MSGSIZEMAX; |
| 1193 | static int msg_maxsize_limit_max = INT_MAX; |
| 1194 | |
| 1195 | static ctl_table mq_sysctls[] = { |
| 1196 | { |
| 1197 | .ctl_name = CTL_QUEUESMAX, |
| 1198 | .procname = "queues_max", |
| 1199 | .data = &queues_max, |
| 1200 | .maxlen = sizeof(int), |
| 1201 | .mode = 0644, |
| 1202 | .proc_handler = &proc_dointvec, |
| 1203 | }, |
| 1204 | { |
| 1205 | .ctl_name = CTL_MSGMAX, |
| 1206 | .procname = "msg_max", |
| 1207 | .data = &msg_max, |
| 1208 | .maxlen = sizeof(int), |
| 1209 | .mode = 0644, |
| 1210 | .proc_handler = &proc_dointvec_minmax, |
| 1211 | .extra1 = &msg_max_limit_min, |
| 1212 | .extra2 = &msg_max_limit_max, |
| 1213 | }, |
| 1214 | { |
| 1215 | .ctl_name = CTL_MSGSIZEMAX, |
| 1216 | .procname = "msgsize_max", |
| 1217 | .data = &msgsize_max, |
| 1218 | .maxlen = sizeof(int), |
| 1219 | .mode = 0644, |
| 1220 | .proc_handler = &proc_dointvec_minmax, |
| 1221 | .extra1 = &msg_maxsize_limit_min, |
| 1222 | .extra2 = &msg_maxsize_limit_max, |
| 1223 | }, |
| 1224 | { .ctl_name = 0 } |
| 1225 | }; |
| 1226 | |
| 1227 | static ctl_table mq_sysctl_dir[] = { |
| 1228 | { |
| 1229 | .ctl_name = FS_MQUEUE, |
| 1230 | .procname = "mqueue", |
| 1231 | .mode = 0555, |
| 1232 | .child = mq_sysctls, |
| 1233 | }, |
| 1234 | { .ctl_name = 0 } |
| 1235 | }; |
| 1236 | |
| 1237 | static ctl_table mq_sysctl_root[] = { |
| 1238 | { |
| 1239 | .ctl_name = CTL_FS, |
| 1240 | .procname = "fs", |
| 1241 | .mode = 0555, |
| 1242 | .child = mq_sysctl_dir, |
| 1243 | }, |
| 1244 | { .ctl_name = 0 } |
| 1245 | }; |
| 1246 | |
| 1247 | static int __init init_mqueue_fs(void) |
| 1248 | { |
| 1249 | int error; |
| 1250 | |
| 1251 | mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache", |
| 1252 | sizeof(struct mqueue_inode_info), 0, |
| 1253 | SLAB_HWCACHE_ALIGN, init_once, NULL); |
| 1254 | if (mqueue_inode_cachep == NULL) |
| 1255 | return -ENOMEM; |
| 1256 | |
| 1257 | /* ignore failues - they are not fatal */ |
Eric W. Biederman | 0b4d414 | 2007-02-14 00:34:09 -0800 | [diff] [blame] | 1258 | mq_sysctl_table = register_sysctl_table(mq_sysctl_root); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1259 | |
| 1260 | error = register_filesystem(&mqueue_fs_type); |
| 1261 | if (error) |
| 1262 | goto out_sysctl; |
| 1263 | |
| 1264 | if (IS_ERR(mqueue_mnt = kern_mount(&mqueue_fs_type))) { |
| 1265 | error = PTR_ERR(mqueue_mnt); |
| 1266 | goto out_filesystem; |
| 1267 | } |
| 1268 | |
| 1269 | /* internal initialization - not common for vfs */ |
| 1270 | queues_count = 0; |
| 1271 | spin_lock_init(&mq_lock); |
| 1272 | |
| 1273 | return 0; |
| 1274 | |
| 1275 | out_filesystem: |
| 1276 | unregister_filesystem(&mqueue_fs_type); |
| 1277 | out_sysctl: |
| 1278 | if (mq_sysctl_table) |
| 1279 | unregister_sysctl_table(mq_sysctl_table); |
Alexey Dobriyan | 1a1d92c | 2006-09-27 01:49:40 -0700 | [diff] [blame] | 1280 | kmem_cache_destroy(mqueue_inode_cachep); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1281 | return error; |
| 1282 | } |
| 1283 | |
| 1284 | __initcall(init_mqueue_fs); |