Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/pipe.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992, 1999 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | #include <linux/mm.h> |
| 8 | #include <linux/file.h> |
| 9 | #include <linux/poll.h> |
| 10 | #include <linux/slab.h> |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/init.h> |
| 13 | #include <linux/fs.h> |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 14 | #include <linux/log2.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/mount.h> |
Muthu Kumar | b502bd1 | 2012-03-23 15:01:50 -0700 | [diff] [blame] | 16 | #include <linux/magic.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/pipe_fs_i.h> |
| 18 | #include <linux/uio.h> |
| 19 | #include <linux/highmem.h> |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 20 | #include <linux/pagemap.h> |
Al Viro | db34950 | 2007-02-07 01:48:00 -0500 | [diff] [blame] | 21 | #include <linux/audit.h> |
Ulrich Drepper | ba719ba | 2008-05-06 20:42:38 -0700 | [diff] [blame] | 22 | #include <linux/syscalls.h> |
Jens Axboe | b492e95 | 2010-05-19 21:03:16 +0200 | [diff] [blame] | 23 | #include <linux/fcntl.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | |
| 25 | #include <asm/uaccess.h> |
| 26 | #include <asm/ioctls.h> |
| 27 | |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 28 | #include "internal.h" |
| 29 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | /* |
Jens Axboe | b492e95 | 2010-05-19 21:03:16 +0200 | [diff] [blame] | 31 | * The max size that a non-root user is allowed to grow the pipe. Can |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 32 | * be set by root in /proc/sys/fs/pipe-max-size |
Jens Axboe | b492e95 | 2010-05-19 21:03:16 +0200 | [diff] [blame] | 33 | */ |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 34 | unsigned int pipe_max_size = 1048576; |
| 35 | |
| 36 | /* |
| 37 | * Minimum pipe size, as required by POSIX |
| 38 | */ |
| 39 | unsigned int pipe_min_size = PAGE_SIZE; |
Jens Axboe | b492e95 | 2010-05-19 21:03:16 +0200 | [diff] [blame] | 40 | |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 41 | /* Maximum allocatable pages per user. Hard limit is unset by default, soft |
| 42 | * matches default values. |
| 43 | */ |
| 44 | unsigned long pipe_user_pages_hard; |
| 45 | unsigned long pipe_user_pages_soft = PIPE_DEF_BUFFERS * INR_OPEN_CUR; |
| 46 | |
Jens Axboe | b492e95 | 2010-05-19 21:03:16 +0200 | [diff] [blame] | 47 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | * We use a start+len construction, which provides full use of the |
| 49 | * allocated memory. |
| 50 | * -- Florian Coosmann (FGC) |
| 51 | * |
| 52 | * Reads with count = 0 should always return 0. |
| 53 | * -- Julian Bradfield 1999-06-07. |
| 54 | * |
| 55 | * FIFOs and Pipes now generate SIGIO for both readers and writers. |
| 56 | * -- Jeremy Elson <jelson@circlemud.org> 2001-08-16 |
| 57 | * |
| 58 | * pipe_read & write cleanup |
| 59 | * -- Manfred Spraul <manfred@colorfullife.com> 2002-05-09 |
| 60 | */ |
| 61 | |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 62 | static void pipe_lock_nested(struct pipe_inode_info *pipe, int subclass) |
| 63 | { |
Al Viro | 6447a3c | 2013-03-21 11:01:38 -0400 | [diff] [blame] | 64 | if (pipe->files) |
Al Viro | 72b0d9a | 2013-03-21 02:32:24 -0400 | [diff] [blame] | 65 | mutex_lock_nested(&pipe->mutex, subclass); |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 66 | } |
| 67 | |
| 68 | void pipe_lock(struct pipe_inode_info *pipe) |
| 69 | { |
| 70 | /* |
| 71 | * pipe_lock() nests non-pipe inode locks (for writing to a file) |
| 72 | */ |
| 73 | pipe_lock_nested(pipe, I_MUTEX_PARENT); |
| 74 | } |
| 75 | EXPORT_SYMBOL(pipe_lock); |
| 76 | |
| 77 | void pipe_unlock(struct pipe_inode_info *pipe) |
| 78 | { |
Al Viro | 6447a3c | 2013-03-21 11:01:38 -0400 | [diff] [blame] | 79 | if (pipe->files) |
Al Viro | 72b0d9a | 2013-03-21 02:32:24 -0400 | [diff] [blame] | 80 | mutex_unlock(&pipe->mutex); |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 81 | } |
| 82 | EXPORT_SYMBOL(pipe_unlock); |
| 83 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 84 | static inline void __pipe_lock(struct pipe_inode_info *pipe) |
| 85 | { |
| 86 | mutex_lock_nested(&pipe->mutex, I_MUTEX_PARENT); |
| 87 | } |
| 88 | |
| 89 | static inline void __pipe_unlock(struct pipe_inode_info *pipe) |
| 90 | { |
| 91 | mutex_unlock(&pipe->mutex); |
| 92 | } |
| 93 | |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 94 | void pipe_double_lock(struct pipe_inode_info *pipe1, |
| 95 | struct pipe_inode_info *pipe2) |
| 96 | { |
| 97 | BUG_ON(pipe1 == pipe2); |
| 98 | |
| 99 | if (pipe1 < pipe2) { |
| 100 | pipe_lock_nested(pipe1, I_MUTEX_PARENT); |
| 101 | pipe_lock_nested(pipe2, I_MUTEX_CHILD); |
| 102 | } else { |
Peter Zijlstra | 023d43c | 2009-07-21 10:09:23 +0200 | [diff] [blame] | 103 | pipe_lock_nested(pipe2, I_MUTEX_PARENT); |
| 104 | pipe_lock_nested(pipe1, I_MUTEX_CHILD); |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 105 | } |
| 106 | } |
| 107 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | /* Drop the inode semaphore and wait for a pipe event, atomically */ |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 109 | void pipe_wait(struct pipe_inode_info *pipe) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | { |
| 111 | DEFINE_WAIT(wait); |
| 112 | |
Ingo Molnar | d79fc0f | 2005-09-10 00:26:12 -0700 | [diff] [blame] | 113 | /* |
| 114 | * Pipes are system-local resources, so sleeping on them |
| 115 | * is considered a noninteractive wait: |
| 116 | */ |
Mike Galbraith | af92723 | 2007-10-15 17:00:13 +0200 | [diff] [blame] | 117 | prepare_to_wait(&pipe->wait, &wait, TASK_INTERRUPTIBLE); |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 118 | pipe_unlock(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | schedule(); |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 120 | finish_wait(&pipe->wait, &wait); |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 121 | pipe_lock(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | } |
| 123 | |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 124 | static void anon_pipe_buf_release(struct pipe_inode_info *pipe, |
| 125 | struct pipe_buffer *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | { |
| 127 | struct page *page = buf->page; |
| 128 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 129 | /* |
| 130 | * If nobody else uses this page, and we don't already have a |
| 131 | * temporary page, let's keep track of it as a one-deep |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 132 | * allocation cache. (Otherwise just release our reference to it) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 133 | */ |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 134 | if (page_count(page) == 1 && !pipe->tmp_page) |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 135 | pipe->tmp_page = page; |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 136 | else |
| 137 | page_cache_release(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | } |
| 139 | |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 140 | /** |
Randy Dunlap | b51d63c | 2008-02-13 15:03:22 -0800 | [diff] [blame] | 141 | * generic_pipe_buf_steal - attempt to take ownership of a &pipe_buffer |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 142 | * @pipe: the pipe that the buffer belongs to |
| 143 | * @buf: the buffer to attempt to steal |
| 144 | * |
| 145 | * Description: |
Randy Dunlap | b51d63c | 2008-02-13 15:03:22 -0800 | [diff] [blame] | 146 | * This function attempts to steal the &struct page attached to |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 147 | * @buf. If successful, this function returns 0 and returns with |
| 148 | * the page locked. The caller may then reuse the page for whatever |
Randy Dunlap | b51d63c | 2008-02-13 15:03:22 -0800 | [diff] [blame] | 149 | * he wishes; the typical use is insertion into a different file |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 150 | * page cache. |
| 151 | */ |
Jens Axboe | 330ab71 | 2006-05-02 15:29:57 +0200 | [diff] [blame] | 152 | int generic_pipe_buf_steal(struct pipe_inode_info *pipe, |
| 153 | struct pipe_buffer *buf) |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 154 | { |
Jens Axboe | 46e678c | 2006-04-30 16:36:32 +0200 | [diff] [blame] | 155 | struct page *page = buf->page; |
| 156 | |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 157 | /* |
| 158 | * A reference of one is golden, that means that the owner of this |
| 159 | * page is the only one holding a reference to it. lock the page |
| 160 | * and return OK. |
| 161 | */ |
Jens Axboe | 46e678c | 2006-04-30 16:36:32 +0200 | [diff] [blame] | 162 | if (page_count(page) == 1) { |
Jens Axboe | 46e678c | 2006-04-30 16:36:32 +0200 | [diff] [blame] | 163 | lock_page(page); |
| 164 | return 0; |
| 165 | } |
| 166 | |
| 167 | return 1; |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 168 | } |
Miklos Szeredi | 51921cb | 2010-05-26 08:44:22 +0200 | [diff] [blame] | 169 | EXPORT_SYMBOL(generic_pipe_buf_steal); |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 170 | |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 171 | /** |
Randy Dunlap | b51d63c | 2008-02-13 15:03:22 -0800 | [diff] [blame] | 172 | * generic_pipe_buf_get - get a reference to a &struct pipe_buffer |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 173 | * @pipe: the pipe that the buffer belongs to |
| 174 | * @buf: the buffer to get a reference to |
| 175 | * |
| 176 | * Description: |
| 177 | * This function grabs an extra reference to @buf. It's used in |
| 178 | * in the tee() system call, when we duplicate the buffers in one |
| 179 | * pipe into another. |
| 180 | */ |
| 181 | void generic_pipe_buf_get(struct pipe_inode_info *pipe, struct pipe_buffer *buf) |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 182 | { |
| 183 | page_cache_get(buf->page); |
| 184 | } |
Miklos Szeredi | 51921cb | 2010-05-26 08:44:22 +0200 | [diff] [blame] | 185 | EXPORT_SYMBOL(generic_pipe_buf_get); |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 186 | |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 187 | /** |
| 188 | * generic_pipe_buf_confirm - verify contents of the pipe buffer |
Randy Dunlap | 79685b8 | 2007-07-27 08:08:51 +0200 | [diff] [blame] | 189 | * @info: the pipe that the buffer belongs to |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 190 | * @buf: the buffer to confirm |
| 191 | * |
| 192 | * Description: |
| 193 | * This function does nothing, because the generic pipe code uses |
| 194 | * pages that are always good when inserted into the pipe. |
| 195 | */ |
Jens Axboe | cac36bb0 | 2007-06-14 13:10:48 +0200 | [diff] [blame] | 196 | int generic_pipe_buf_confirm(struct pipe_inode_info *info, |
| 197 | struct pipe_buffer *buf) |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 198 | { |
| 199 | return 0; |
| 200 | } |
Miklos Szeredi | 51921cb | 2010-05-26 08:44:22 +0200 | [diff] [blame] | 201 | EXPORT_SYMBOL(generic_pipe_buf_confirm); |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 202 | |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 203 | /** |
| 204 | * generic_pipe_buf_release - put a reference to a &struct pipe_buffer |
| 205 | * @pipe: the pipe that the buffer belongs to |
| 206 | * @buf: the buffer to put a reference to |
| 207 | * |
| 208 | * Description: |
| 209 | * This function releases a reference to @buf. |
| 210 | */ |
| 211 | void generic_pipe_buf_release(struct pipe_inode_info *pipe, |
| 212 | struct pipe_buffer *buf) |
| 213 | { |
| 214 | page_cache_release(buf->page); |
| 215 | } |
Miklos Szeredi | 51921cb | 2010-05-26 08:44:22 +0200 | [diff] [blame] | 216 | EXPORT_SYMBOL(generic_pipe_buf_release); |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 217 | |
Eric Dumazet | d4c3cca | 2006-12-13 00:34:04 -0800 | [diff] [blame] | 218 | static const struct pipe_buf_operations anon_pipe_buf_ops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 219 | .can_merge = 1, |
Jens Axboe | cac36bb0 | 2007-06-14 13:10:48 +0200 | [diff] [blame] | 220 | .confirm = generic_pipe_buf_confirm, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 221 | .release = anon_pipe_buf_release, |
Jens Axboe | 330ab71 | 2006-05-02 15:29:57 +0200 | [diff] [blame] | 222 | .steal = generic_pipe_buf_steal, |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 223 | .get = generic_pipe_buf_get, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | }; |
| 225 | |
Linus Torvalds | 9883035a | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 226 | static const struct pipe_buf_operations packet_pipe_buf_ops = { |
| 227 | .can_merge = 0, |
Linus Torvalds | 9883035a | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 228 | .confirm = generic_pipe_buf_confirm, |
| 229 | .release = anon_pipe_buf_release, |
| 230 | .steal = generic_pipe_buf_steal, |
| 231 | .get = generic_pipe_buf_get, |
| 232 | }; |
| 233 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | static ssize_t |
Al Viro | fb9096a | 2014-04-02 19:56:54 -0400 | [diff] [blame] | 235 | pipe_read(struct kiocb *iocb, struct iov_iter *to) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | { |
Al Viro | fb9096a | 2014-04-02 19:56:54 -0400 | [diff] [blame] | 237 | size_t total_len = iov_iter_count(to); |
Badari Pulavarty | ee0b3e6 | 2006-09-30 23:28:47 -0700 | [diff] [blame] | 238 | struct file *filp = iocb->ki_filp; |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 239 | struct pipe_inode_info *pipe = filp->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | int do_wakeup; |
| 241 | ssize_t ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | /* Null read succeeds. */ |
| 244 | if (unlikely(total_len == 0)) |
| 245 | return 0; |
| 246 | |
| 247 | do_wakeup = 0; |
| 248 | ret = 0; |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 249 | __pipe_lock(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 250 | for (;;) { |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 251 | int bufs = pipe->nrbufs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 252 | if (bufs) { |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 253 | int curbuf = pipe->curbuf; |
| 254 | struct pipe_buffer *buf = pipe->bufs + curbuf; |
Eric Dumazet | d4c3cca | 2006-12-13 00:34:04 -0800 | [diff] [blame] | 255 | const struct pipe_buf_operations *ops = buf->ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | size_t chars = buf->len; |
Al Viro | 637b58c | 2014-02-03 19:11:42 -0500 | [diff] [blame] | 257 | size_t written; |
| 258 | int error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 259 | |
| 260 | if (chars > total_len) |
| 261 | chars = total_len; |
| 262 | |
Jens Axboe | cac36bb0 | 2007-06-14 13:10:48 +0200 | [diff] [blame] | 263 | error = ops->confirm(pipe, buf); |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 264 | if (error) { |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 265 | if (!ret) |
Nicolas Kaiser | e5953cb | 2010-10-21 14:56:00 +0200 | [diff] [blame] | 266 | ret = error; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 267 | break; |
| 268 | } |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 269 | |
Al Viro | fb9096a | 2014-04-02 19:56:54 -0400 | [diff] [blame] | 270 | written = copy_page_to_iter(buf->page, buf->offset, chars, to); |
Al Viro | 637b58c | 2014-02-03 19:11:42 -0500 | [diff] [blame] | 271 | if (unlikely(written < chars)) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 272 | if (!ret) |
Al Viro | 637b58c | 2014-02-03 19:11:42 -0500 | [diff] [blame] | 273 | ret = -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | break; |
| 275 | } |
| 276 | ret += chars; |
| 277 | buf->offset += chars; |
| 278 | buf->len -= chars; |
Linus Torvalds | 9883035a | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 279 | |
| 280 | /* Was it a packet buffer? Clean up and exit */ |
| 281 | if (buf->flags & PIPE_BUF_FLAG_PACKET) { |
| 282 | total_len = chars; |
| 283 | buf->len = 0; |
| 284 | } |
| 285 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 286 | if (!buf->len) { |
| 287 | buf->ops = NULL; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 288 | ops->release(pipe, buf); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 289 | curbuf = (curbuf + 1) & (pipe->buffers - 1); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 290 | pipe->curbuf = curbuf; |
| 291 | pipe->nrbufs = --bufs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 292 | do_wakeup = 1; |
| 293 | } |
| 294 | total_len -= chars; |
| 295 | if (!total_len) |
| 296 | break; /* common path: read succeeded */ |
| 297 | } |
| 298 | if (bufs) /* More to do? */ |
| 299 | continue; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 300 | if (!pipe->writers) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 301 | break; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 302 | if (!pipe->waiting_writers) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 303 | /* syscall merging: Usually we must not sleep |
| 304 | * if O_NONBLOCK is set, or if we got some data. |
| 305 | * But if a writer sleeps in kernel space, then |
| 306 | * we can wait for that data without violating POSIX. |
| 307 | */ |
| 308 | if (ret) |
| 309 | break; |
| 310 | if (filp->f_flags & O_NONBLOCK) { |
| 311 | ret = -EAGAIN; |
| 312 | break; |
| 313 | } |
| 314 | } |
| 315 | if (signal_pending(current)) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 316 | if (!ret) |
| 317 | ret = -ERESTARTSYS; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | break; |
| 319 | } |
| 320 | if (do_wakeup) { |
Linus Torvalds | 28e58ee | 2011-01-20 16:21:59 -0800 | [diff] [blame] | 321 | wake_up_interruptible_sync_poll(&pipe->wait, POLLOUT | POLLWRNORM); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 322 | kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 323 | } |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 324 | pipe_wait(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 325 | } |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 326 | __pipe_unlock(pipe); |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 327 | |
| 328 | /* Signal writers asynchronously that there is more room. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | if (do_wakeup) { |
Linus Torvalds | 28e58ee | 2011-01-20 16:21:59 -0800 | [diff] [blame] | 330 | wake_up_interruptible_sync_poll(&pipe->wait, POLLOUT | POLLWRNORM); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 331 | kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 332 | } |
| 333 | if (ret > 0) |
| 334 | file_accessed(filp); |
| 335 | return ret; |
| 336 | } |
| 337 | |
Linus Torvalds | 9883035a | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 338 | static inline int is_packetized(struct file *file) |
| 339 | { |
| 340 | return (file->f_flags & O_DIRECT) != 0; |
| 341 | } |
| 342 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 343 | static ssize_t |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 344 | pipe_write(struct kiocb *iocb, struct iov_iter *from) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | { |
Badari Pulavarty | ee0b3e6 | 2006-09-30 23:28:47 -0700 | [diff] [blame] | 346 | struct file *filp = iocb->ki_filp; |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 347 | struct pipe_inode_info *pipe = filp->private_data; |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 348 | ssize_t ret = 0; |
| 349 | int do_wakeup = 0; |
| 350 | size_t total_len = iov_iter_count(from); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | ssize_t chars; |
| 352 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 353 | /* Null write succeeds. */ |
| 354 | if (unlikely(total_len == 0)) |
| 355 | return 0; |
| 356 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 357 | __pipe_lock(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 358 | |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 359 | if (!pipe->readers) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | send_sig(SIGPIPE, current, 0); |
| 361 | ret = -EPIPE; |
| 362 | goto out; |
| 363 | } |
| 364 | |
| 365 | /* We try to merge small writes */ |
| 366 | chars = total_len & (PAGE_SIZE-1); /* size of the last buffer */ |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 367 | if (pipe->nrbufs && chars != 0) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 368 | int lastbuf = (pipe->curbuf + pipe->nrbufs - 1) & |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 369 | (pipe->buffers - 1); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 370 | struct pipe_buffer *buf = pipe->bufs + lastbuf; |
Eric Dumazet | d4c3cca | 2006-12-13 00:34:04 -0800 | [diff] [blame] | 371 | const struct pipe_buf_operations *ops = buf->ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | int offset = buf->offset + buf->len; |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 373 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 374 | if (ops->can_merge && offset + chars <= PAGE_SIZE) { |
Eric Biggers | 6ae0806 | 2015-10-17 16:26:09 -0500 | [diff] [blame] | 375 | ret = ops->confirm(pipe, buf); |
| 376 | if (ret) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 377 | goto out; |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 378 | |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 379 | ret = copy_page_from_iter(buf->page, offset, chars, from); |
| 380 | if (unlikely(ret < chars)) { |
Eric Biggers | 6ae0806 | 2015-10-17 16:26:09 -0500 | [diff] [blame] | 381 | ret = -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 382 | goto out; |
Jens Axboe | f6762b7 | 2006-05-01 20:02:05 +0200 | [diff] [blame] | 383 | } |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 384 | do_wakeup = 1; |
Eric Biggers | 6ae0806 | 2015-10-17 16:26:09 -0500 | [diff] [blame] | 385 | buf->len += ret; |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 386 | if (!iov_iter_count(from)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | goto out; |
| 388 | } |
| 389 | } |
| 390 | |
| 391 | for (;;) { |
| 392 | int bufs; |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 393 | |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 394 | if (!pipe->readers) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 395 | send_sig(SIGPIPE, current, 0); |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 396 | if (!ret) |
| 397 | ret = -EPIPE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 398 | break; |
| 399 | } |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 400 | bufs = pipe->nrbufs; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 401 | if (bufs < pipe->buffers) { |
| 402 | int newbuf = (pipe->curbuf + bufs) & (pipe->buffers-1); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 403 | struct pipe_buffer *buf = pipe->bufs + newbuf; |
| 404 | struct page *page = pipe->tmp_page; |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 405 | int copied; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 406 | |
| 407 | if (!page) { |
| 408 | page = alloc_page(GFP_HIGHUSER); |
| 409 | if (unlikely(!page)) { |
| 410 | ret = ret ? : -ENOMEM; |
| 411 | break; |
| 412 | } |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 413 | pipe->tmp_page = page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 414 | } |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 415 | /* Always wake up, even if the copy fails. Otherwise |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 416 | * we lock up (O_NONBLOCK-)readers that sleep due to |
| 417 | * syscall merging. |
| 418 | * FIXME! Is this really true? |
| 419 | */ |
| 420 | do_wakeup = 1; |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 421 | copied = copy_page_from_iter(page, 0, PAGE_SIZE, from); |
| 422 | if (unlikely(copied < PAGE_SIZE && iov_iter_count(from))) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 423 | if (!ret) |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 424 | ret = -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 425 | break; |
| 426 | } |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 427 | ret += copied; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 428 | |
| 429 | /* Insert it into the buffer array */ |
| 430 | buf->page = page; |
| 431 | buf->ops = &anon_pipe_buf_ops; |
| 432 | buf->offset = 0; |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 433 | buf->len = copied; |
Linus Torvalds | 9883035a | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 434 | buf->flags = 0; |
| 435 | if (is_packetized(filp)) { |
| 436 | buf->ops = &packet_pipe_buf_ops; |
| 437 | buf->flags = PIPE_BUF_FLAG_PACKET; |
| 438 | } |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 439 | pipe->nrbufs = ++bufs; |
| 440 | pipe->tmp_page = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 441 | |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 442 | if (!iov_iter_count(from)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 443 | break; |
| 444 | } |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 445 | if (bufs < pipe->buffers) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | continue; |
| 447 | if (filp->f_flags & O_NONBLOCK) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 448 | if (!ret) |
| 449 | ret = -EAGAIN; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | break; |
| 451 | } |
| 452 | if (signal_pending(current)) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 453 | if (!ret) |
| 454 | ret = -ERESTARTSYS; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | break; |
| 456 | } |
| 457 | if (do_wakeup) { |
Linus Torvalds | 28e58ee | 2011-01-20 16:21:59 -0800 | [diff] [blame] | 458 | wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLRDNORM); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 459 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 460 | do_wakeup = 0; |
| 461 | } |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 462 | pipe->waiting_writers++; |
| 463 | pipe_wait(pipe); |
| 464 | pipe->waiting_writers--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | } |
| 466 | out: |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 467 | __pipe_unlock(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | if (do_wakeup) { |
Linus Torvalds | 28e58ee | 2011-01-20 16:21:59 -0800 | [diff] [blame] | 469 | wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLRDNORM); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 470 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 471 | } |
Dmitry Monakhov | 7e775f4 | 2014-01-23 15:55:21 -0800 | [diff] [blame] | 472 | if (ret > 0 && sb_start_write_trylock(file_inode(filp)->i_sb)) { |
Josef Bacik | c3b2da3 | 2012-03-26 09:59:21 -0400 | [diff] [blame] | 473 | int err = file_update_time(filp); |
| 474 | if (err) |
| 475 | ret = err; |
Dmitry Monakhov | 7e775f4 | 2014-01-23 15:55:21 -0800 | [diff] [blame] | 476 | sb_end_write(file_inode(filp)->i_sb); |
Josef Bacik | c3b2da3 | 2012-03-26 09:59:21 -0400 | [diff] [blame] | 477 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | return ret; |
| 479 | } |
| 480 | |
Andi Kleen | d59d0b1 | 2008-02-08 04:21:23 -0800 | [diff] [blame] | 481 | static long pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | { |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 483 | struct pipe_inode_info *pipe = filp->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | int count, buf, nrbufs; |
| 485 | |
| 486 | switch (cmd) { |
| 487 | case FIONREAD: |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 488 | __pipe_lock(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 489 | count = 0; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 490 | buf = pipe->curbuf; |
| 491 | nrbufs = pipe->nrbufs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 492 | while (--nrbufs >= 0) { |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 493 | count += pipe->bufs[buf].len; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 494 | buf = (buf+1) & (pipe->buffers - 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | } |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 496 | __pipe_unlock(pipe); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 497 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | return put_user(count, (int __user *)arg); |
| 499 | default: |
Will Deacon | 46ce341 | 2012-05-25 11:39:13 +0100 | [diff] [blame] | 500 | return -ENOIOCTLCMD; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 501 | } |
| 502 | } |
| 503 | |
| 504 | /* No kernel lock held - fine */ |
| 505 | static unsigned int |
| 506 | pipe_poll(struct file *filp, poll_table *wait) |
| 507 | { |
| 508 | unsigned int mask; |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 509 | struct pipe_inode_info *pipe = filp->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 510 | int nrbufs; |
| 511 | |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 512 | poll_wait(filp, &pipe->wait, wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 513 | |
| 514 | /* Reading only -- no need for acquiring the semaphore. */ |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 515 | nrbufs = pipe->nrbufs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 516 | mask = 0; |
| 517 | if (filp->f_mode & FMODE_READ) { |
| 518 | mask = (nrbufs > 0) ? POLLIN | POLLRDNORM : 0; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 519 | if (!pipe->writers && filp->f_version != pipe->w_counter) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 520 | mask |= POLLHUP; |
| 521 | } |
| 522 | |
| 523 | if (filp->f_mode & FMODE_WRITE) { |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 524 | mask |= (nrbufs < pipe->buffers) ? POLLOUT | POLLWRNORM : 0; |
Pekka Enberg | 5e5d7a2 | 2005-09-06 15:17:48 -0700 | [diff] [blame] | 525 | /* |
| 526 | * Most Unices do not set POLLERR for FIFOs but on Linux they |
| 527 | * behave exactly like pipes for poll(). |
| 528 | */ |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 529 | if (!pipe->readers) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | mask |= POLLERR; |
| 531 | } |
| 532 | |
| 533 | return mask; |
| 534 | } |
| 535 | |
Linus Torvalds | b0d8d22 | 2013-12-02 09:44:51 -0800 | [diff] [blame] | 536 | static void put_pipe_info(struct inode *inode, struct pipe_inode_info *pipe) |
| 537 | { |
| 538 | int kill = 0; |
| 539 | |
| 540 | spin_lock(&inode->i_lock); |
| 541 | if (!--pipe->files) { |
| 542 | inode->i_pipe = NULL; |
| 543 | kill = 1; |
| 544 | } |
| 545 | spin_unlock(&inode->i_lock); |
| 546 | |
| 547 | if (kill) |
| 548 | free_pipe_info(pipe); |
| 549 | } |
| 550 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 551 | static int |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 552 | pipe_release(struct inode *inode, struct file *file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 553 | { |
Linus Torvalds | b0d8d22 | 2013-12-02 09:44:51 -0800 | [diff] [blame] | 554 | struct pipe_inode_info *pipe = file->private_data; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 555 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 556 | __pipe_lock(pipe); |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 557 | if (file->f_mode & FMODE_READ) |
| 558 | pipe->readers--; |
| 559 | if (file->f_mode & FMODE_WRITE) |
| 560 | pipe->writers--; |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 561 | |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 562 | if (pipe->readers || pipe->writers) { |
Linus Torvalds | 28e58ee | 2011-01-20 16:21:59 -0800 | [diff] [blame] | 563 | wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM | POLLERR | POLLHUP); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 564 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); |
| 565 | kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 566 | } |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 567 | __pipe_unlock(pipe); |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 568 | |
Linus Torvalds | b0d8d22 | 2013-12-02 09:44:51 -0800 | [diff] [blame] | 569 | put_pipe_info(inode, pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | return 0; |
| 571 | } |
| 572 | |
| 573 | static int |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 574 | pipe_fasync(int fd, struct file *filp, int on) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 575 | { |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 576 | struct pipe_inode_info *pipe = filp->private_data; |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 577 | int retval = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 578 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 579 | __pipe_lock(pipe); |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 580 | if (filp->f_mode & FMODE_READ) |
| 581 | retval = fasync_helper(fd, filp, on, &pipe->fasync_readers); |
| 582 | if ((filp->f_mode & FMODE_WRITE) && retval >= 0) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 583 | retval = fasync_helper(fd, filp, on, &pipe->fasync_writers); |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 584 | if (retval < 0 && (filp->f_mode & FMODE_READ)) |
| 585 | /* this can happen only if on == T */ |
Oleg Nesterov | e5bc49b | 2009-03-12 14:31:28 -0700 | [diff] [blame] | 586 | fasync_helper(-1, filp, 0, &pipe->fasync_readers); |
| 587 | } |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 588 | __pipe_unlock(pipe); |
Jonathan Corbet | 60aa492 | 2009-02-01 14:52:56 -0700 | [diff] [blame] | 589 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 590 | } |
| 591 | |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 592 | static void account_pipe_buffers(struct pipe_inode_info *pipe, |
| 593 | unsigned long old, unsigned long new) |
| 594 | { |
| 595 | atomic_long_add(new - old, &pipe->user->pipe_bufs); |
| 596 | } |
| 597 | |
| 598 | static bool too_many_pipe_buffers_soft(struct user_struct *user) |
| 599 | { |
| 600 | return pipe_user_pages_soft && |
| 601 | atomic_long_read(&user->pipe_bufs) >= pipe_user_pages_soft; |
| 602 | } |
| 603 | |
| 604 | static bool too_many_pipe_buffers_hard(struct user_struct *user) |
| 605 | { |
| 606 | return pipe_user_pages_hard && |
| 607 | atomic_long_read(&user->pipe_bufs) >= pipe_user_pages_hard; |
| 608 | } |
| 609 | |
Al Viro | 7bee130 | 2013-03-21 11:04:15 -0400 | [diff] [blame] | 610 | struct pipe_inode_info *alloc_pipe_info(void) |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 611 | { |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 612 | struct pipe_inode_info *pipe; |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 613 | |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 614 | pipe = kzalloc(sizeof(struct pipe_inode_info), GFP_KERNEL); |
| 615 | if (pipe) { |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 616 | unsigned long pipe_bufs = PIPE_DEF_BUFFERS; |
| 617 | struct user_struct *user = get_current_user(); |
| 618 | |
| 619 | if (!too_many_pipe_buffers_hard(user)) { |
| 620 | if (too_many_pipe_buffers_soft(user)) |
| 621 | pipe_bufs = 1; |
| 622 | pipe->bufs = kzalloc(sizeof(struct pipe_buffer) * pipe_bufs, GFP_KERNEL); |
| 623 | } |
| 624 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 625 | if (pipe->bufs) { |
| 626 | init_waitqueue_head(&pipe->wait); |
| 627 | pipe->r_counter = pipe->w_counter = 1; |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 628 | pipe->buffers = pipe_bufs; |
| 629 | pipe->user = user; |
| 630 | account_pipe_buffers(pipe, 0, pipe_bufs); |
Al Viro | 72b0d9a | 2013-03-21 02:32:24 -0400 | [diff] [blame] | 631 | mutex_init(&pipe->mutex); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 632 | return pipe; |
| 633 | } |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 634 | free_uid(user); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 635 | kfree(pipe); |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 636 | } |
| 637 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 638 | return NULL; |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 639 | } |
| 640 | |
Al Viro | 4b8a8f1 | 2013-03-21 11:06:46 -0400 | [diff] [blame] | 641 | void free_pipe_info(struct pipe_inode_info *pipe) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 642 | { |
| 643 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 644 | |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 645 | account_pipe_buffers(pipe, pipe->buffers, 0); |
| 646 | free_uid(pipe->user); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 647 | for (i = 0; i < pipe->buffers; i++) { |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 648 | struct pipe_buffer *buf = pipe->bufs + i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 649 | if (buf->ops) |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 650 | buf->ops->release(pipe, buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 651 | } |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 652 | if (pipe->tmp_page) |
| 653 | __free_page(pipe->tmp_page); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 654 | kfree(pipe->bufs); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 655 | kfree(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 656 | } |
| 657 | |
Eric Dumazet | fa3536c | 2006-03-26 01:37:24 -0800 | [diff] [blame] | 658 | static struct vfsmount *pipe_mnt __read_mostly; |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 659 | |
Eric Dumazet | c23fbb6 | 2007-05-08 00:26:18 -0700 | [diff] [blame] | 660 | /* |
| 661 | * pipefs_dname() is called from d_path(). |
| 662 | */ |
| 663 | static char *pipefs_dname(struct dentry *dentry, char *buffer, int buflen) |
| 664 | { |
| 665 | return dynamic_dname(dentry, buffer, buflen, "pipe:[%lu]", |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 666 | d_inode(dentry)->i_ino); |
Eric Dumazet | c23fbb6 | 2007-05-08 00:26:18 -0700 | [diff] [blame] | 667 | } |
| 668 | |
Al Viro | 3ba13d1 | 2009-02-20 06:02:22 +0000 | [diff] [blame] | 669 | static const struct dentry_operations pipefs_dentry_operations = { |
Eric Dumazet | c23fbb6 | 2007-05-08 00:26:18 -0700 | [diff] [blame] | 670 | .d_dname = pipefs_dname, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 671 | }; |
| 672 | |
| 673 | static struct inode * get_pipe_inode(void) |
| 674 | { |
Eric Dumazet | a209dfc | 2011-07-26 11:36:34 +0200 | [diff] [blame] | 675 | struct inode *inode = new_inode_pseudo(pipe_mnt->mnt_sb); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 676 | struct pipe_inode_info *pipe; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 677 | |
| 678 | if (!inode) |
| 679 | goto fail_inode; |
| 680 | |
Christoph Hellwig | 85fe402 | 2010-10-23 11:19:54 -0400 | [diff] [blame] | 681 | inode->i_ino = get_next_ino(); |
| 682 | |
Al Viro | 7bee130 | 2013-03-21 11:04:15 -0400 | [diff] [blame] | 683 | pipe = alloc_pipe_info(); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 684 | if (!pipe) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 685 | goto fail_iput; |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 686 | |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 687 | inode->i_pipe = pipe; |
| 688 | pipe->files = 2; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 689 | pipe->readers = pipe->writers = 1; |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 690 | inode->i_fop = &pipefifo_fops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | |
| 692 | /* |
| 693 | * Mark the inode dirty from the very beginning, |
| 694 | * that way it will never be moved to the dirty |
| 695 | * list because "mark_inode_dirty()" will think |
| 696 | * that it already _is_ on the dirty list. |
| 697 | */ |
| 698 | inode->i_state = I_DIRTY; |
| 699 | inode->i_mode = S_IFIFO | S_IRUSR | S_IWUSR; |
David Howells | da9592e | 2008-11-14 10:39:05 +1100 | [diff] [blame] | 700 | inode->i_uid = current_fsuid(); |
| 701 | inode->i_gid = current_fsgid(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 702 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 703 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 704 | return inode; |
| 705 | |
| 706 | fail_iput: |
| 707 | iput(inode); |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 708 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 709 | fail_inode: |
| 710 | return NULL; |
| 711 | } |
| 712 | |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 713 | int create_pipe_files(struct file **res, int flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 714 | { |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 715 | int err; |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 716 | struct inode *inode = get_pipe_inode(); |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 717 | struct file *f; |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 718 | struct path path; |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 719 | static struct qstr name = { .name = "" }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 720 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 721 | if (!inode) |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 722 | return -ENFILE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 723 | |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 724 | err = -ENOMEM; |
Nick Piggin | 4b93688 | 2011-01-07 17:50:07 +1100 | [diff] [blame] | 725 | path.dentry = d_alloc_pseudo(pipe_mnt->mnt_sb, &name); |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 726 | if (!path.dentry) |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 727 | goto err_inode; |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 728 | path.mnt = mntget(pipe_mnt); |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 729 | |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 730 | d_instantiate(path.dentry, inode); |
Dave Hansen | 430e285 | 2008-02-15 14:37:26 -0800 | [diff] [blame] | 731 | |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 732 | f = alloc_file(&path, FMODE_WRITE, &pipefifo_fops); |
Eric Biggers | e9bb1f9 | 2015-10-17 16:26:08 -0500 | [diff] [blame] | 733 | if (IS_ERR(f)) { |
| 734 | err = PTR_ERR(f); |
Dave Hansen | 430e285 | 2008-02-15 14:37:26 -0800 | [diff] [blame] | 735 | goto err_dentry; |
Eric Biggers | e9bb1f9 | 2015-10-17 16:26:08 -0500 | [diff] [blame] | 736 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 737 | |
Linus Torvalds | 9883035a | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 738 | f->f_flags = O_WRONLY | (flags & (O_NONBLOCK | O_DIRECT)); |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 739 | f->private_data = inode->i_pipe; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 740 | |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 741 | res[0] = alloc_file(&path, FMODE_READ, &pipefifo_fops); |
Eric Biggers | e9bb1f9 | 2015-10-17 16:26:08 -0500 | [diff] [blame] | 742 | if (IS_ERR(res[0])) { |
| 743 | err = PTR_ERR(res[0]); |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 744 | goto err_file; |
Eric Biggers | e9bb1f9 | 2015-10-17 16:26:08 -0500 | [diff] [blame] | 745 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 746 | |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 747 | path_get(&path); |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 748 | res[0]->private_data = inode->i_pipe; |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 749 | res[0]->f_flags = O_RDONLY | (flags & O_NONBLOCK); |
| 750 | res[1] = f; |
| 751 | return 0; |
| 752 | |
| 753 | err_file: |
| 754 | put_filp(f); |
| 755 | err_dentry: |
Al Viro | 4b8a8f1 | 2013-03-21 11:06:46 -0400 | [diff] [blame] | 756 | free_pipe_info(inode->i_pipe); |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 757 | path_put(&path); |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 758 | return err; |
Al Viro | ed15243 | 2008-04-22 19:51:27 -0400 | [diff] [blame] | 759 | |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 760 | err_inode: |
Al Viro | 4b8a8f1 | 2013-03-21 11:06:46 -0400 | [diff] [blame] | 761 | free_pipe_info(inode->i_pipe); |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 762 | iput(inode); |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 763 | return err; |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 764 | } |
| 765 | |
Al Viro | 5b249b1 | 2012-08-19 12:17:29 -0400 | [diff] [blame] | 766 | static int __do_pipe_flags(int *fd, struct file **files, int flags) |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 767 | { |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 768 | int error; |
| 769 | int fdw, fdr; |
| 770 | |
Linus Torvalds | 9883035a | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 771 | if (flags & ~(O_CLOEXEC | O_NONBLOCK | O_DIRECT)) |
Ulrich Drepper | ed8cae8 | 2008-07-23 21:29:30 -0700 | [diff] [blame] | 772 | return -EINVAL; |
| 773 | |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 774 | error = create_pipe_files(files, flags); |
| 775 | if (error) |
| 776 | return error; |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 777 | |
Ulrich Drepper | ed8cae8 | 2008-07-23 21:29:30 -0700 | [diff] [blame] | 778 | error = get_unused_fd_flags(flags); |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 779 | if (error < 0) |
| 780 | goto err_read_pipe; |
| 781 | fdr = error; |
| 782 | |
Ulrich Drepper | ed8cae8 | 2008-07-23 21:29:30 -0700 | [diff] [blame] | 783 | error = get_unused_fd_flags(flags); |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 784 | if (error < 0) |
| 785 | goto err_fdr; |
| 786 | fdw = error; |
| 787 | |
Al Viro | 157cf64 | 2008-12-14 04:57:47 -0500 | [diff] [blame] | 788 | audit_fd_pair(fdr, fdw); |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 789 | fd[0] = fdr; |
| 790 | fd[1] = fdw; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 791 | return 0; |
| 792 | |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 793 | err_fdr: |
| 794 | put_unused_fd(fdr); |
| 795 | err_read_pipe: |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 796 | fput(files[0]); |
| 797 | fput(files[1]); |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 798 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 799 | } |
| 800 | |
Al Viro | 5b249b1 | 2012-08-19 12:17:29 -0400 | [diff] [blame] | 801 | int do_pipe_flags(int *fd, int flags) |
| 802 | { |
| 803 | struct file *files[2]; |
| 804 | int error = __do_pipe_flags(fd, files, flags); |
| 805 | if (!error) { |
| 806 | fd_install(fd[0], files[0]); |
| 807 | fd_install(fd[1], files[1]); |
| 808 | } |
| 809 | return error; |
| 810 | } |
| 811 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 812 | /* |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 813 | * sys_pipe() is the normal C calling standard for creating |
| 814 | * a pipe. It's not the way Unix traditionally does this, though. |
| 815 | */ |
Heiko Carstens | d4e8204 | 2009-01-14 14:14:34 +0100 | [diff] [blame] | 816 | SYSCALL_DEFINE2(pipe2, int __user *, fildes, int, flags) |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 817 | { |
Al Viro | 5b249b1 | 2012-08-19 12:17:29 -0400 | [diff] [blame] | 818 | struct file *files[2]; |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 819 | int fd[2]; |
| 820 | int error; |
| 821 | |
Al Viro | 5b249b1 | 2012-08-19 12:17:29 -0400 | [diff] [blame] | 822 | error = __do_pipe_flags(fd, files, flags); |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 823 | if (!error) { |
Al Viro | 5b249b1 | 2012-08-19 12:17:29 -0400 | [diff] [blame] | 824 | if (unlikely(copy_to_user(fildes, fd, sizeof(fd)))) { |
| 825 | fput(files[0]); |
| 826 | fput(files[1]); |
| 827 | put_unused_fd(fd[0]); |
| 828 | put_unused_fd(fd[1]); |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 829 | error = -EFAULT; |
Al Viro | 5b249b1 | 2012-08-19 12:17:29 -0400 | [diff] [blame] | 830 | } else { |
| 831 | fd_install(fd[0], files[0]); |
| 832 | fd_install(fd[1], files[1]); |
Ulrich Drepper | ba719ba | 2008-05-06 20:42:38 -0700 | [diff] [blame] | 833 | } |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 834 | } |
| 835 | return error; |
| 836 | } |
| 837 | |
Heiko Carstens | 2b66421 | 2009-01-14 14:14:35 +0100 | [diff] [blame] | 838 | SYSCALL_DEFINE1(pipe, int __user *, fildes) |
Ulrich Drepper | ed8cae8 | 2008-07-23 21:29:30 -0700 | [diff] [blame] | 839 | { |
| 840 | return sys_pipe2(fildes, 0); |
| 841 | } |
| 842 | |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 843 | static int wait_for_partner(struct pipe_inode_info *pipe, unsigned int *cnt) |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 844 | { |
| 845 | int cur = *cnt; |
| 846 | |
| 847 | while (cur == *cnt) { |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 848 | pipe_wait(pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 849 | if (signal_pending(current)) |
| 850 | break; |
| 851 | } |
| 852 | return cur == *cnt ? -ERESTARTSYS : 0; |
| 853 | } |
| 854 | |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 855 | static void wake_up_partner(struct pipe_inode_info *pipe) |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 856 | { |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 857 | wake_up_interruptible(&pipe->wait); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 858 | } |
| 859 | |
| 860 | static int fifo_open(struct inode *inode, struct file *filp) |
| 861 | { |
| 862 | struct pipe_inode_info *pipe; |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 863 | bool is_pipe = inode->i_sb->s_magic == PIPEFS_MAGIC; |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 864 | int ret; |
| 865 | |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 866 | filp->f_version = 0; |
| 867 | |
| 868 | spin_lock(&inode->i_lock); |
| 869 | if (inode->i_pipe) { |
| 870 | pipe = inode->i_pipe; |
| 871 | pipe->files++; |
| 872 | spin_unlock(&inode->i_lock); |
| 873 | } else { |
| 874 | spin_unlock(&inode->i_lock); |
Al Viro | 7bee130 | 2013-03-21 11:04:15 -0400 | [diff] [blame] | 875 | pipe = alloc_pipe_info(); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 876 | if (!pipe) |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 877 | return -ENOMEM; |
| 878 | pipe->files = 1; |
| 879 | spin_lock(&inode->i_lock); |
| 880 | if (unlikely(inode->i_pipe)) { |
| 881 | inode->i_pipe->files++; |
| 882 | spin_unlock(&inode->i_lock); |
Al Viro | 4b8a8f1 | 2013-03-21 11:06:46 -0400 | [diff] [blame] | 883 | free_pipe_info(pipe); |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 884 | pipe = inode->i_pipe; |
| 885 | } else { |
| 886 | inode->i_pipe = pipe; |
| 887 | spin_unlock(&inode->i_lock); |
| 888 | } |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 889 | } |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 890 | filp->private_data = pipe; |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 891 | /* OK, we have a pipe and it's pinned down */ |
| 892 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 893 | __pipe_lock(pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 894 | |
| 895 | /* We can only do regular read/write on fifos */ |
| 896 | filp->f_mode &= (FMODE_READ | FMODE_WRITE); |
| 897 | |
| 898 | switch (filp->f_mode) { |
| 899 | case FMODE_READ: |
| 900 | /* |
| 901 | * O_RDONLY |
| 902 | * POSIX.1 says that O_NONBLOCK means return with the FIFO |
| 903 | * opened, even when there is no process writing the FIFO. |
| 904 | */ |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 905 | pipe->r_counter++; |
| 906 | if (pipe->readers++ == 0) |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 907 | wake_up_partner(pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 908 | |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 909 | if (!is_pipe && !pipe->writers) { |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 910 | if ((filp->f_flags & O_NONBLOCK)) { |
| 911 | /* suppress POLLHUP until we have |
| 912 | * seen a writer */ |
| 913 | filp->f_version = pipe->w_counter; |
| 914 | } else { |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 915 | if (wait_for_partner(pipe, &pipe->w_counter)) |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 916 | goto err_rd; |
| 917 | } |
| 918 | } |
| 919 | break; |
| 920 | |
| 921 | case FMODE_WRITE: |
| 922 | /* |
| 923 | * O_WRONLY |
| 924 | * POSIX.1 says that O_NONBLOCK means return -1 with |
| 925 | * errno=ENXIO when there is no process reading the FIFO. |
| 926 | */ |
| 927 | ret = -ENXIO; |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 928 | if (!is_pipe && (filp->f_flags & O_NONBLOCK) && !pipe->readers) |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 929 | goto err; |
| 930 | |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 931 | pipe->w_counter++; |
| 932 | if (!pipe->writers++) |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 933 | wake_up_partner(pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 934 | |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 935 | if (!is_pipe && !pipe->readers) { |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 936 | if (wait_for_partner(pipe, &pipe->r_counter)) |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 937 | goto err_wr; |
| 938 | } |
| 939 | break; |
| 940 | |
| 941 | case FMODE_READ | FMODE_WRITE: |
| 942 | /* |
| 943 | * O_RDWR |
| 944 | * POSIX.1 leaves this case "undefined" when O_NONBLOCK is set. |
| 945 | * This implementation will NEVER block on a O_RDWR open, since |
| 946 | * the process can at least talk to itself. |
| 947 | */ |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 948 | |
| 949 | pipe->readers++; |
| 950 | pipe->writers++; |
| 951 | pipe->r_counter++; |
| 952 | pipe->w_counter++; |
| 953 | if (pipe->readers == 1 || pipe->writers == 1) |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 954 | wake_up_partner(pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 955 | break; |
| 956 | |
| 957 | default: |
| 958 | ret = -EINVAL; |
| 959 | goto err; |
| 960 | } |
| 961 | |
| 962 | /* Ok! */ |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 963 | __pipe_unlock(pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 964 | return 0; |
| 965 | |
| 966 | err_rd: |
| 967 | if (!--pipe->readers) |
| 968 | wake_up_interruptible(&pipe->wait); |
| 969 | ret = -ERESTARTSYS; |
| 970 | goto err; |
| 971 | |
| 972 | err_wr: |
| 973 | if (!--pipe->writers) |
| 974 | wake_up_interruptible(&pipe->wait); |
| 975 | ret = -ERESTARTSYS; |
| 976 | goto err; |
| 977 | |
| 978 | err: |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 979 | __pipe_unlock(pipe); |
Linus Torvalds | b0d8d22 | 2013-12-02 09:44:51 -0800 | [diff] [blame] | 980 | |
| 981 | put_pipe_info(inode, pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 982 | return ret; |
| 983 | } |
| 984 | |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 985 | const struct file_operations pipefifo_fops = { |
| 986 | .open = fifo_open, |
| 987 | .llseek = no_llseek, |
Al Viro | fb9096a | 2014-04-02 19:56:54 -0400 | [diff] [blame] | 988 | .read_iter = pipe_read, |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 989 | .write_iter = pipe_write, |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 990 | .poll = pipe_poll, |
| 991 | .unlocked_ioctl = pipe_ioctl, |
| 992 | .release = pipe_release, |
| 993 | .fasync = pipe_fasync, |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 994 | }; |
| 995 | |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 996 | /* |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 997 | * Allocate a new array of pipe buffers and copy the info over. Returns the |
| 998 | * pipe size if successful, or return -ERROR on error. |
| 999 | */ |
Jens Axboe | b9598db | 2010-05-24 19:34:43 +0200 | [diff] [blame] | 1000 | static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long nr_pages) |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1001 | { |
| 1002 | struct pipe_buffer *bufs; |
| 1003 | |
| 1004 | /* |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1005 | * We can shrink the pipe, if arg >= pipe->nrbufs. Since we don't |
| 1006 | * expect a lot of shrink+grow operations, just free and allocate |
| 1007 | * again like we would do for growing. If the pipe currently |
| 1008 | * contains more buffers than arg, then return busy. |
| 1009 | */ |
Jens Axboe | b9598db | 2010-05-24 19:34:43 +0200 | [diff] [blame] | 1010 | if (nr_pages < pipe->nrbufs) |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1011 | return -EBUSY; |
| 1012 | |
Sasha Levin | 2ccd4f4 | 2012-01-12 17:17:40 -0800 | [diff] [blame] | 1013 | bufs = kcalloc(nr_pages, sizeof(*bufs), GFP_KERNEL | __GFP_NOWARN); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1014 | if (unlikely(!bufs)) |
| 1015 | return -ENOMEM; |
| 1016 | |
| 1017 | /* |
| 1018 | * The pipe array wraps around, so just start the new one at zero |
| 1019 | * and adjust the indexes. |
| 1020 | */ |
| 1021 | if (pipe->nrbufs) { |
Miklos Szeredi | 1d862f4 | 2010-06-08 16:28:45 +0200 | [diff] [blame] | 1022 | unsigned int tail; |
| 1023 | unsigned int head; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1024 | |
Miklos Szeredi | 1d862f4 | 2010-06-08 16:28:45 +0200 | [diff] [blame] | 1025 | tail = pipe->curbuf + pipe->nrbufs; |
| 1026 | if (tail < pipe->buffers) |
| 1027 | tail = 0; |
| 1028 | else |
| 1029 | tail &= (pipe->buffers - 1); |
| 1030 | |
| 1031 | head = pipe->nrbufs - tail; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1032 | if (head) |
| 1033 | memcpy(bufs, pipe->bufs + pipe->curbuf, head * sizeof(struct pipe_buffer)); |
| 1034 | if (tail) |
Miklos Szeredi | 1d862f4 | 2010-06-08 16:28:45 +0200 | [diff] [blame] | 1035 | memcpy(bufs + head, pipe->bufs, tail * sizeof(struct pipe_buffer)); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1036 | } |
| 1037 | |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 1038 | account_pipe_buffers(pipe, pipe->buffers, nr_pages); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1039 | pipe->curbuf = 0; |
| 1040 | kfree(pipe->bufs); |
| 1041 | pipe->bufs = bufs; |
Jens Axboe | b9598db | 2010-05-24 19:34:43 +0200 | [diff] [blame] | 1042 | pipe->buffers = nr_pages; |
| 1043 | return nr_pages * PAGE_SIZE; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1044 | } |
| 1045 | |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 1046 | /* |
| 1047 | * Currently we rely on the pipe array holding a power-of-2 number |
| 1048 | * of pages. |
| 1049 | */ |
| 1050 | static inline unsigned int round_pipe_size(unsigned int size) |
| 1051 | { |
| 1052 | unsigned long nr_pages; |
| 1053 | |
| 1054 | nr_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 1055 | return roundup_pow_of_two(nr_pages) << PAGE_SHIFT; |
| 1056 | } |
| 1057 | |
| 1058 | /* |
| 1059 | * This should work even if CONFIG_PROC_FS isn't set, as proc_dointvec_minmax |
| 1060 | * will return an error. |
| 1061 | */ |
| 1062 | int pipe_proc_fn(struct ctl_table *table, int write, void __user *buf, |
| 1063 | size_t *lenp, loff_t *ppos) |
| 1064 | { |
| 1065 | int ret; |
| 1066 | |
| 1067 | ret = proc_dointvec_minmax(table, write, buf, lenp, ppos); |
| 1068 | if (ret < 0 || !write) |
| 1069 | return ret; |
| 1070 | |
| 1071 | pipe_max_size = round_pipe_size(pipe_max_size); |
| 1072 | return ret; |
| 1073 | } |
| 1074 | |
Linus Torvalds | 7208364 | 2010-11-28 16:27:19 -0800 | [diff] [blame] | 1075 | /* |
| 1076 | * After the inode slimming patch, i_pipe/i_bdev/i_cdev share the same |
| 1077 | * location, so checking ->i_pipe is not enough to verify that this is a |
| 1078 | * pipe. |
| 1079 | */ |
| 1080 | struct pipe_inode_info *get_pipe_info(struct file *file) |
| 1081 | { |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 1082 | return file->f_op == &pipefifo_fops ? file->private_data : NULL; |
Linus Torvalds | 7208364 | 2010-11-28 16:27:19 -0800 | [diff] [blame] | 1083 | } |
| 1084 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1085 | long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg) |
| 1086 | { |
| 1087 | struct pipe_inode_info *pipe; |
| 1088 | long ret; |
| 1089 | |
Linus Torvalds | c66fb34 | 2010-11-28 14:09:57 -0800 | [diff] [blame] | 1090 | pipe = get_pipe_info(file); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1091 | if (!pipe) |
| 1092 | return -EBADF; |
| 1093 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 1094 | __pipe_lock(pipe); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1095 | |
| 1096 | switch (cmd) { |
Jens Axboe | b9598db | 2010-05-24 19:34:43 +0200 | [diff] [blame] | 1097 | case F_SETPIPE_SZ: { |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 1098 | unsigned int size, nr_pages; |
Jens Axboe | b9598db | 2010-05-24 19:34:43 +0200 | [diff] [blame] | 1099 | |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 1100 | size = round_pipe_size(arg); |
| 1101 | nr_pages = size >> PAGE_SHIFT; |
Jens Axboe | b9598db | 2010-05-24 19:34:43 +0200 | [diff] [blame] | 1102 | |
Miklos Szeredi | 6db40cf | 2010-06-09 09:27:57 +0200 | [diff] [blame] | 1103 | ret = -EINVAL; |
| 1104 | if (!nr_pages) |
| 1105 | goto out; |
| 1106 | |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 1107 | if (!capable(CAP_SYS_RESOURCE) && size > pipe_max_size) { |
Jens Axboe | b4ca761 | 2010-06-01 12:42:12 +0200 | [diff] [blame] | 1108 | ret = -EPERM; |
Julia Lawall | cc967be | 2010-05-26 17:54:39 +0200 | [diff] [blame] | 1109 | goto out; |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 1110 | } else if ((too_many_pipe_buffers_hard(pipe->user) || |
| 1111 | too_many_pipe_buffers_soft(pipe->user)) && |
| 1112 | !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN)) { |
| 1113 | ret = -EPERM; |
| 1114 | goto out; |
Julia Lawall | cc967be | 2010-05-26 17:54:39 +0200 | [diff] [blame] | 1115 | } |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 1116 | ret = pipe_set_size(pipe, nr_pages); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1117 | break; |
Jens Axboe | b9598db | 2010-05-24 19:34:43 +0200 | [diff] [blame] | 1118 | } |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1119 | case F_GETPIPE_SZ: |
Jens Axboe | b9598db | 2010-05-24 19:34:43 +0200 | [diff] [blame] | 1120 | ret = pipe->buffers * PAGE_SIZE; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1121 | break; |
| 1122 | default: |
| 1123 | ret = -EINVAL; |
| 1124 | break; |
| 1125 | } |
| 1126 | |
Julia Lawall | cc967be | 2010-05-26 17:54:39 +0200 | [diff] [blame] | 1127 | out: |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 1128 | __pipe_unlock(pipe); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1129 | return ret; |
| 1130 | } |
| 1131 | |
Nick Piggin | ff0c7d1 | 2011-01-07 17:49:50 +1100 | [diff] [blame] | 1132 | static const struct super_operations pipefs_ops = { |
| 1133 | .destroy_inode = free_inode_nonrcu, |
Pavel Emelyanov | d70ef97 | 2011-10-31 17:10:04 -0700 | [diff] [blame] | 1134 | .statfs = simple_statfs, |
Nick Piggin | ff0c7d1 | 2011-01-07 17:49:50 +1100 | [diff] [blame] | 1135 | }; |
| 1136 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1137 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1138 | * pipefs should _never_ be mounted by userland - too much of security hassle, |
| 1139 | * no real gain from having the whole whorehouse mounted. So we don't need |
| 1140 | * any operations on the root directory. However, we need a non-trivial |
| 1141 | * d_name - pipe: will go nicely and kill the special-casing in procfs. |
| 1142 | */ |
Al Viro | 51139ad | 2010-07-25 23:47:46 +0400 | [diff] [blame] | 1143 | static struct dentry *pipefs_mount(struct file_system_type *fs_type, |
| 1144 | int flags, const char *dev_name, void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1145 | { |
Al Viro | c74a1cb | 2011-01-12 16:59:34 -0500 | [diff] [blame] | 1146 | return mount_pseudo(fs_type, "pipe:", &pipefs_ops, |
| 1147 | &pipefs_dentry_operations, PIPEFS_MAGIC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1148 | } |
| 1149 | |
| 1150 | static struct file_system_type pipe_fs_type = { |
| 1151 | .name = "pipefs", |
Al Viro | 51139ad | 2010-07-25 23:47:46 +0400 | [diff] [blame] | 1152 | .mount = pipefs_mount, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1153 | .kill_sb = kill_anon_super, |
| 1154 | }; |
| 1155 | |
| 1156 | static int __init init_pipe_fs(void) |
| 1157 | { |
| 1158 | int err = register_filesystem(&pipe_fs_type); |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 1159 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1160 | if (!err) { |
| 1161 | pipe_mnt = kern_mount(&pipe_fs_type); |
| 1162 | if (IS_ERR(pipe_mnt)) { |
| 1163 | err = PTR_ERR(pipe_mnt); |
| 1164 | unregister_filesystem(&pipe_fs_type); |
| 1165 | } |
| 1166 | } |
| 1167 | return err; |
| 1168 | } |
| 1169 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1170 | fs_initcall(init_pipe_fs); |