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> |
Vladimir Davydov | d86133b | 2016-07-26 15:24:33 -0700 | [diff] [blame^] | 24 | #include <linux/memcontrol.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | |
| 26 | #include <asm/uaccess.h> |
| 27 | #include <asm/ioctls.h> |
| 28 | |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 29 | #include "internal.h" |
| 30 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | /* |
Jens Axboe | b492e95 | 2010-05-19 21:03:16 +0200 | [diff] [blame] | 32 | * 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] | 33 | * be set by root in /proc/sys/fs/pipe-max-size |
Jens Axboe | b492e95 | 2010-05-19 21:03:16 +0200 | [diff] [blame] | 34 | */ |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 35 | unsigned int pipe_max_size = 1048576; |
| 36 | |
| 37 | /* |
| 38 | * Minimum pipe size, as required by POSIX |
| 39 | */ |
| 40 | unsigned int pipe_min_size = PAGE_SIZE; |
Jens Axboe | b492e95 | 2010-05-19 21:03:16 +0200 | [diff] [blame] | 41 | |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 42 | /* Maximum allocatable pages per user. Hard limit is unset by default, soft |
| 43 | * matches default values. |
| 44 | */ |
| 45 | unsigned long pipe_user_pages_hard; |
| 46 | unsigned long pipe_user_pages_soft = PIPE_DEF_BUFFERS * INR_OPEN_CUR; |
| 47 | |
Jens Axboe | b492e95 | 2010-05-19 21:03:16 +0200 | [diff] [blame] | 48 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | * We use a start+len construction, which provides full use of the |
| 50 | * allocated memory. |
| 51 | * -- Florian Coosmann (FGC) |
| 52 | * |
| 53 | * Reads with count = 0 should always return 0. |
| 54 | * -- Julian Bradfield 1999-06-07. |
| 55 | * |
| 56 | * FIFOs and Pipes now generate SIGIO for both readers and writers. |
| 57 | * -- Jeremy Elson <jelson@circlemud.org> 2001-08-16 |
| 58 | * |
| 59 | * pipe_read & write cleanup |
| 60 | * -- Manfred Spraul <manfred@colorfullife.com> 2002-05-09 |
| 61 | */ |
| 62 | |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 63 | static void pipe_lock_nested(struct pipe_inode_info *pipe, int subclass) |
| 64 | { |
Al Viro | 6447a3c | 2013-03-21 11:01:38 -0400 | [diff] [blame] | 65 | if (pipe->files) |
Al Viro | 72b0d9a | 2013-03-21 02:32:24 -0400 | [diff] [blame] | 66 | mutex_lock_nested(&pipe->mutex, subclass); |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 67 | } |
| 68 | |
| 69 | void pipe_lock(struct pipe_inode_info *pipe) |
| 70 | { |
| 71 | /* |
| 72 | * pipe_lock() nests non-pipe inode locks (for writing to a file) |
| 73 | */ |
| 74 | pipe_lock_nested(pipe, I_MUTEX_PARENT); |
| 75 | } |
| 76 | EXPORT_SYMBOL(pipe_lock); |
| 77 | |
| 78 | void pipe_unlock(struct pipe_inode_info *pipe) |
| 79 | { |
Al Viro | 6447a3c | 2013-03-21 11:01:38 -0400 | [diff] [blame] | 80 | if (pipe->files) |
Al Viro | 72b0d9a | 2013-03-21 02:32:24 -0400 | [diff] [blame] | 81 | mutex_unlock(&pipe->mutex); |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 82 | } |
| 83 | EXPORT_SYMBOL(pipe_unlock); |
| 84 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 85 | static inline void __pipe_lock(struct pipe_inode_info *pipe) |
| 86 | { |
| 87 | mutex_lock_nested(&pipe->mutex, I_MUTEX_PARENT); |
| 88 | } |
| 89 | |
| 90 | static inline void __pipe_unlock(struct pipe_inode_info *pipe) |
| 91 | { |
| 92 | mutex_unlock(&pipe->mutex); |
| 93 | } |
| 94 | |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 95 | void pipe_double_lock(struct pipe_inode_info *pipe1, |
| 96 | struct pipe_inode_info *pipe2) |
| 97 | { |
| 98 | BUG_ON(pipe1 == pipe2); |
| 99 | |
| 100 | if (pipe1 < pipe2) { |
| 101 | pipe_lock_nested(pipe1, I_MUTEX_PARENT); |
| 102 | pipe_lock_nested(pipe2, I_MUTEX_CHILD); |
| 103 | } else { |
Peter Zijlstra | 023d43c | 2009-07-21 10:09:23 +0200 | [diff] [blame] | 104 | pipe_lock_nested(pipe2, I_MUTEX_PARENT); |
| 105 | pipe_lock_nested(pipe1, I_MUTEX_CHILD); |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 106 | } |
| 107 | } |
| 108 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | /* Drop the inode semaphore and wait for a pipe event, atomically */ |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 110 | void pipe_wait(struct pipe_inode_info *pipe) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | { |
| 112 | DEFINE_WAIT(wait); |
| 113 | |
Ingo Molnar | d79fc0f | 2005-09-10 00:26:12 -0700 | [diff] [blame] | 114 | /* |
| 115 | * Pipes are system-local resources, so sleeping on them |
| 116 | * is considered a noninteractive wait: |
| 117 | */ |
Mike Galbraith | af92723 | 2007-10-15 17:00:13 +0200 | [diff] [blame] | 118 | prepare_to_wait(&pipe->wait, &wait, TASK_INTERRUPTIBLE); |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 119 | pipe_unlock(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | schedule(); |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 121 | finish_wait(&pipe->wait, &wait); |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 122 | pipe_lock(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 123 | } |
| 124 | |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 125 | static void anon_pipe_buf_release(struct pipe_inode_info *pipe, |
| 126 | struct pipe_buffer *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | { |
| 128 | struct page *page = buf->page; |
| 129 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 130 | /* |
| 131 | * If nobody else uses this page, and we don't already have a |
| 132 | * temporary page, let's keep track of it as a one-deep |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 133 | * allocation cache. (Otherwise just release our reference to it) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 134 | */ |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 135 | if (page_count(page) == 1 && !pipe->tmp_page) |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 136 | pipe->tmp_page = page; |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 137 | else |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 138 | put_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | } |
| 140 | |
Vladimir Davydov | d86133b | 2016-07-26 15:24:33 -0700 | [diff] [blame^] | 141 | static int anon_pipe_buf_steal(struct pipe_inode_info *pipe, |
| 142 | struct pipe_buffer *buf) |
| 143 | { |
| 144 | struct page *page = buf->page; |
| 145 | |
| 146 | if (page_count(page) == 1) { |
| 147 | if (memcg_kmem_enabled()) { |
| 148 | memcg_kmem_uncharge(page, 0); |
| 149 | __ClearPageKmemcg(page); |
| 150 | } |
| 151 | __SetPageLocked(page); |
| 152 | return 0; |
| 153 | } |
| 154 | return 1; |
| 155 | } |
| 156 | |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 157 | /** |
Randy Dunlap | b51d63c | 2008-02-13 15:03:22 -0800 | [diff] [blame] | 158 | * generic_pipe_buf_steal - attempt to take ownership of a &pipe_buffer |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 159 | * @pipe: the pipe that the buffer belongs to |
| 160 | * @buf: the buffer to attempt to steal |
| 161 | * |
| 162 | * Description: |
Randy Dunlap | b51d63c | 2008-02-13 15:03:22 -0800 | [diff] [blame] | 163 | * This function attempts to steal the &struct page attached to |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 164 | * @buf. If successful, this function returns 0 and returns with |
| 165 | * the page locked. The caller may then reuse the page for whatever |
Randy Dunlap | b51d63c | 2008-02-13 15:03:22 -0800 | [diff] [blame] | 166 | * he wishes; the typical use is insertion into a different file |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 167 | * page cache. |
| 168 | */ |
Jens Axboe | 330ab71 | 2006-05-02 15:29:57 +0200 | [diff] [blame] | 169 | int generic_pipe_buf_steal(struct pipe_inode_info *pipe, |
| 170 | struct pipe_buffer *buf) |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 171 | { |
Jens Axboe | 46e678c | 2006-04-30 16:36:32 +0200 | [diff] [blame] | 172 | struct page *page = buf->page; |
| 173 | |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 174 | /* |
| 175 | * A reference of one is golden, that means that the owner of this |
| 176 | * page is the only one holding a reference to it. lock the page |
| 177 | * and return OK. |
| 178 | */ |
Jens Axboe | 46e678c | 2006-04-30 16:36:32 +0200 | [diff] [blame] | 179 | if (page_count(page) == 1) { |
Jens Axboe | 46e678c | 2006-04-30 16:36:32 +0200 | [diff] [blame] | 180 | lock_page(page); |
| 181 | return 0; |
| 182 | } |
| 183 | |
| 184 | return 1; |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 185 | } |
Miklos Szeredi | 51921cb | 2010-05-26 08:44:22 +0200 | [diff] [blame] | 186 | EXPORT_SYMBOL(generic_pipe_buf_steal); |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 187 | |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 188 | /** |
Randy Dunlap | b51d63c | 2008-02-13 15:03:22 -0800 | [diff] [blame] | 189 | * generic_pipe_buf_get - get a reference to a &struct pipe_buffer |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 190 | * @pipe: the pipe that the buffer belongs to |
| 191 | * @buf: the buffer to get a reference to |
| 192 | * |
| 193 | * Description: |
| 194 | * This function grabs an extra reference to @buf. It's used in |
| 195 | * in the tee() system call, when we duplicate the buffers in one |
| 196 | * pipe into another. |
| 197 | */ |
| 198 | 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] | 199 | { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 200 | get_page(buf->page); |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 201 | } |
Miklos Szeredi | 51921cb | 2010-05-26 08:44:22 +0200 | [diff] [blame] | 202 | EXPORT_SYMBOL(generic_pipe_buf_get); |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 203 | |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 204 | /** |
| 205 | * generic_pipe_buf_confirm - verify contents of the pipe buffer |
Randy Dunlap | 79685b8 | 2007-07-27 08:08:51 +0200 | [diff] [blame] | 206 | * @info: the pipe that the buffer belongs to |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 207 | * @buf: the buffer to confirm |
| 208 | * |
| 209 | * Description: |
| 210 | * This function does nothing, because the generic pipe code uses |
| 211 | * pages that are always good when inserted into the pipe. |
| 212 | */ |
Jens Axboe | cac36bb0 | 2007-06-14 13:10:48 +0200 | [diff] [blame] | 213 | int generic_pipe_buf_confirm(struct pipe_inode_info *info, |
| 214 | struct pipe_buffer *buf) |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 215 | { |
| 216 | return 0; |
| 217 | } |
Miklos Szeredi | 51921cb | 2010-05-26 08:44:22 +0200 | [diff] [blame] | 218 | EXPORT_SYMBOL(generic_pipe_buf_confirm); |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 219 | |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 220 | /** |
| 221 | * generic_pipe_buf_release - put a reference to a &struct pipe_buffer |
| 222 | * @pipe: the pipe that the buffer belongs to |
| 223 | * @buf: the buffer to put a reference to |
| 224 | * |
| 225 | * Description: |
| 226 | * This function releases a reference to @buf. |
| 227 | */ |
| 228 | void generic_pipe_buf_release(struct pipe_inode_info *pipe, |
| 229 | struct pipe_buffer *buf) |
| 230 | { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 231 | put_page(buf->page); |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 232 | } |
Miklos Szeredi | 51921cb | 2010-05-26 08:44:22 +0200 | [diff] [blame] | 233 | EXPORT_SYMBOL(generic_pipe_buf_release); |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 234 | |
Eric Dumazet | d4c3cca | 2006-12-13 00:34:04 -0800 | [diff] [blame] | 235 | static const struct pipe_buf_operations anon_pipe_buf_ops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | .can_merge = 1, |
Jens Axboe | cac36bb0 | 2007-06-14 13:10:48 +0200 | [diff] [blame] | 237 | .confirm = generic_pipe_buf_confirm, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | .release = anon_pipe_buf_release, |
Vladimir Davydov | d86133b | 2016-07-26 15:24:33 -0700 | [diff] [blame^] | 239 | .steal = anon_pipe_buf_steal, |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 240 | .get = generic_pipe_buf_get, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 241 | }; |
| 242 | |
Linus Torvalds | 9883035 | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 243 | static const struct pipe_buf_operations packet_pipe_buf_ops = { |
| 244 | .can_merge = 0, |
Linus Torvalds | 9883035 | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 245 | .confirm = generic_pipe_buf_confirm, |
| 246 | .release = anon_pipe_buf_release, |
Vladimir Davydov | d86133b | 2016-07-26 15:24:33 -0700 | [diff] [blame^] | 247 | .steal = anon_pipe_buf_steal, |
Linus Torvalds | 9883035 | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 248 | .get = generic_pipe_buf_get, |
| 249 | }; |
| 250 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | static ssize_t |
Al Viro | fb9096a | 2014-04-02 19:56:54 -0400 | [diff] [blame] | 252 | pipe_read(struct kiocb *iocb, struct iov_iter *to) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 253 | { |
Al Viro | fb9096a | 2014-04-02 19:56:54 -0400 | [diff] [blame] | 254 | size_t total_len = iov_iter_count(to); |
Badari Pulavarty | ee0b3e6 | 2006-09-30 23:28:47 -0700 | [diff] [blame] | 255 | struct file *filp = iocb->ki_filp; |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 256 | struct pipe_inode_info *pipe = filp->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | int do_wakeup; |
| 258 | ssize_t ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 259 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | /* Null read succeeds. */ |
| 261 | if (unlikely(total_len == 0)) |
| 262 | return 0; |
| 263 | |
| 264 | do_wakeup = 0; |
| 265 | ret = 0; |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 266 | __pipe_lock(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | for (;;) { |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 268 | int bufs = pipe->nrbufs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 269 | if (bufs) { |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 270 | int curbuf = pipe->curbuf; |
| 271 | struct pipe_buffer *buf = pipe->bufs + curbuf; |
Eric Dumazet | d4c3cca | 2006-12-13 00:34:04 -0800 | [diff] [blame] | 272 | const struct pipe_buf_operations *ops = buf->ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 273 | size_t chars = buf->len; |
Al Viro | 637b58c | 2014-02-03 19:11:42 -0500 | [diff] [blame] | 274 | size_t written; |
| 275 | int error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 276 | |
| 277 | if (chars > total_len) |
| 278 | chars = total_len; |
| 279 | |
Jens Axboe | cac36bb0 | 2007-06-14 13:10:48 +0200 | [diff] [blame] | 280 | error = ops->confirm(pipe, buf); |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 281 | if (error) { |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 282 | if (!ret) |
Nicolas Kaiser | e5953cb | 2010-10-21 14:56:00 +0200 | [diff] [blame] | 283 | ret = error; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 284 | break; |
| 285 | } |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 286 | |
Al Viro | fb9096a | 2014-04-02 19:56:54 -0400 | [diff] [blame] | 287 | written = copy_page_to_iter(buf->page, buf->offset, chars, to); |
Al Viro | 637b58c | 2014-02-03 19:11:42 -0500 | [diff] [blame] | 288 | if (unlikely(written < chars)) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 289 | if (!ret) |
Al Viro | 637b58c | 2014-02-03 19:11:42 -0500 | [diff] [blame] | 290 | ret = -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | break; |
| 292 | } |
| 293 | ret += chars; |
| 294 | buf->offset += chars; |
| 295 | buf->len -= chars; |
Linus Torvalds | 9883035 | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 296 | |
| 297 | /* Was it a packet buffer? Clean up and exit */ |
| 298 | if (buf->flags & PIPE_BUF_FLAG_PACKET) { |
| 299 | total_len = chars; |
| 300 | buf->len = 0; |
| 301 | } |
| 302 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 303 | if (!buf->len) { |
| 304 | buf->ops = NULL; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 305 | ops->release(pipe, buf); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 306 | curbuf = (curbuf + 1) & (pipe->buffers - 1); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 307 | pipe->curbuf = curbuf; |
| 308 | pipe->nrbufs = --bufs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | do_wakeup = 1; |
| 310 | } |
| 311 | total_len -= chars; |
| 312 | if (!total_len) |
| 313 | break; /* common path: read succeeded */ |
| 314 | } |
| 315 | if (bufs) /* More to do? */ |
| 316 | continue; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 317 | if (!pipe->writers) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | break; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 319 | if (!pipe->waiting_writers) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 320 | /* syscall merging: Usually we must not sleep |
| 321 | * if O_NONBLOCK is set, or if we got some data. |
| 322 | * But if a writer sleeps in kernel space, then |
| 323 | * we can wait for that data without violating POSIX. |
| 324 | */ |
| 325 | if (ret) |
| 326 | break; |
| 327 | if (filp->f_flags & O_NONBLOCK) { |
| 328 | ret = -EAGAIN; |
| 329 | break; |
| 330 | } |
| 331 | } |
| 332 | if (signal_pending(current)) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 333 | if (!ret) |
| 334 | ret = -ERESTARTSYS; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | break; |
| 336 | } |
| 337 | if (do_wakeup) { |
Linus Torvalds | 28e58ee | 2011-01-20 16:21:59 -0800 | [diff] [blame] | 338 | wake_up_interruptible_sync_poll(&pipe->wait, POLLOUT | POLLWRNORM); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 339 | kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 340 | } |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 341 | pipe_wait(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 342 | } |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 343 | __pipe_unlock(pipe); |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 344 | |
| 345 | /* Signal writers asynchronously that there is more room. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 346 | if (do_wakeup) { |
Linus Torvalds | 28e58ee | 2011-01-20 16:21:59 -0800 | [diff] [blame] | 347 | wake_up_interruptible_sync_poll(&pipe->wait, POLLOUT | POLLWRNORM); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 348 | kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 349 | } |
| 350 | if (ret > 0) |
| 351 | file_accessed(filp); |
| 352 | return ret; |
| 353 | } |
| 354 | |
Linus Torvalds | 9883035 | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 355 | static inline int is_packetized(struct file *file) |
| 356 | { |
| 357 | return (file->f_flags & O_DIRECT) != 0; |
| 358 | } |
| 359 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | static ssize_t |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 361 | pipe_write(struct kiocb *iocb, struct iov_iter *from) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 362 | { |
Badari Pulavarty | ee0b3e6 | 2006-09-30 23:28:47 -0700 | [diff] [blame] | 363 | struct file *filp = iocb->ki_filp; |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 364 | struct pipe_inode_info *pipe = filp->private_data; |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 365 | ssize_t ret = 0; |
| 366 | int do_wakeup = 0; |
| 367 | size_t total_len = iov_iter_count(from); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 368 | ssize_t chars; |
| 369 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 370 | /* Null write succeeds. */ |
| 371 | if (unlikely(total_len == 0)) |
| 372 | return 0; |
| 373 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 374 | __pipe_lock(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 376 | if (!pipe->readers) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | send_sig(SIGPIPE, current, 0); |
| 378 | ret = -EPIPE; |
| 379 | goto out; |
| 380 | } |
| 381 | |
| 382 | /* We try to merge small writes */ |
| 383 | chars = total_len & (PAGE_SIZE-1); /* size of the last buffer */ |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 384 | if (pipe->nrbufs && chars != 0) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 385 | int lastbuf = (pipe->curbuf + pipe->nrbufs - 1) & |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 386 | (pipe->buffers - 1); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 387 | struct pipe_buffer *buf = pipe->bufs + lastbuf; |
Eric Dumazet | d4c3cca | 2006-12-13 00:34:04 -0800 | [diff] [blame] | 388 | const struct pipe_buf_operations *ops = buf->ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 389 | int offset = buf->offset + buf->len; |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 390 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | if (ops->can_merge && offset + chars <= PAGE_SIZE) { |
Eric Biggers | 6ae0806 | 2015-10-17 16:26:09 -0500 | [diff] [blame] | 392 | ret = ops->confirm(pipe, buf); |
| 393 | if (ret) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 394 | goto out; |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 395 | |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 396 | ret = copy_page_from_iter(buf->page, offset, chars, from); |
| 397 | if (unlikely(ret < chars)) { |
Eric Biggers | 6ae0806 | 2015-10-17 16:26:09 -0500 | [diff] [blame] | 398 | ret = -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 399 | goto out; |
Jens Axboe | f6762b7 | 2006-05-01 20:02:05 +0200 | [diff] [blame] | 400 | } |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 401 | do_wakeup = 1; |
Eric Biggers | 6ae0806 | 2015-10-17 16:26:09 -0500 | [diff] [blame] | 402 | buf->len += ret; |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 403 | if (!iov_iter_count(from)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 404 | goto out; |
| 405 | } |
| 406 | } |
| 407 | |
| 408 | for (;;) { |
| 409 | int bufs; |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 410 | |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 411 | if (!pipe->readers) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 412 | send_sig(SIGPIPE, current, 0); |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 413 | if (!ret) |
| 414 | ret = -EPIPE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 415 | break; |
| 416 | } |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 417 | bufs = pipe->nrbufs; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 418 | if (bufs < pipe->buffers) { |
| 419 | int newbuf = (pipe->curbuf + bufs) & (pipe->buffers-1); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 420 | struct pipe_buffer *buf = pipe->bufs + newbuf; |
| 421 | struct page *page = pipe->tmp_page; |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 422 | int copied; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | |
| 424 | if (!page) { |
Vladimir Davydov | d86133b | 2016-07-26 15:24:33 -0700 | [diff] [blame^] | 425 | page = alloc_page(GFP_HIGHUSER | __GFP_ACCOUNT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 426 | if (unlikely(!page)) { |
| 427 | ret = ret ? : -ENOMEM; |
| 428 | break; |
| 429 | } |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 430 | pipe->tmp_page = page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 431 | } |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 432 | /* Always wake up, even if the copy fails. Otherwise |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | * we lock up (O_NONBLOCK-)readers that sleep due to |
| 434 | * syscall merging. |
| 435 | * FIXME! Is this really true? |
| 436 | */ |
| 437 | do_wakeup = 1; |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 438 | copied = copy_page_from_iter(page, 0, PAGE_SIZE, from); |
| 439 | if (unlikely(copied < PAGE_SIZE && iov_iter_count(from))) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 440 | if (!ret) |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 441 | ret = -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | break; |
| 443 | } |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 444 | ret += copied; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 445 | |
| 446 | /* Insert it into the buffer array */ |
| 447 | buf->page = page; |
| 448 | buf->ops = &anon_pipe_buf_ops; |
| 449 | buf->offset = 0; |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 450 | buf->len = copied; |
Linus Torvalds | 9883035 | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 451 | buf->flags = 0; |
| 452 | if (is_packetized(filp)) { |
| 453 | buf->ops = &packet_pipe_buf_ops; |
| 454 | buf->flags = PIPE_BUF_FLAG_PACKET; |
| 455 | } |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 456 | pipe->nrbufs = ++bufs; |
| 457 | pipe->tmp_page = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 459 | if (!iov_iter_count(from)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 460 | break; |
| 461 | } |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 462 | if (bufs < pipe->buffers) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | continue; |
| 464 | if (filp->f_flags & O_NONBLOCK) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 465 | if (!ret) |
| 466 | ret = -EAGAIN; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | break; |
| 468 | } |
| 469 | if (signal_pending(current)) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 470 | if (!ret) |
| 471 | ret = -ERESTARTSYS; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 472 | break; |
| 473 | } |
| 474 | if (do_wakeup) { |
Linus Torvalds | 28e58ee | 2011-01-20 16:21:59 -0800 | [diff] [blame] | 475 | wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLRDNORM); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 476 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 477 | do_wakeup = 0; |
| 478 | } |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 479 | pipe->waiting_writers++; |
| 480 | pipe_wait(pipe); |
| 481 | pipe->waiting_writers--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | } |
| 483 | out: |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 484 | __pipe_unlock(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | if (do_wakeup) { |
Linus Torvalds | 28e58ee | 2011-01-20 16:21:59 -0800 | [diff] [blame] | 486 | wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLRDNORM); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 487 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 488 | } |
Dmitry Monakhov | 7e775f4 | 2014-01-23 15:55:21 -0800 | [diff] [blame] | 489 | if (ret > 0 && sb_start_write_trylock(file_inode(filp)->i_sb)) { |
Josef Bacik | c3b2da3 | 2012-03-26 09:59:21 -0400 | [diff] [blame] | 490 | int err = file_update_time(filp); |
| 491 | if (err) |
| 492 | ret = err; |
Dmitry Monakhov | 7e775f4 | 2014-01-23 15:55:21 -0800 | [diff] [blame] | 493 | sb_end_write(file_inode(filp)->i_sb); |
Josef Bacik | c3b2da3 | 2012-03-26 09:59:21 -0400 | [diff] [blame] | 494 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | return ret; |
| 496 | } |
| 497 | |
Andi Kleen | d59d0b1 | 2008-02-08 04:21:23 -0800 | [diff] [blame] | 498 | 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] | 499 | { |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 500 | struct pipe_inode_info *pipe = filp->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 501 | int count, buf, nrbufs; |
| 502 | |
| 503 | switch (cmd) { |
| 504 | case FIONREAD: |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 505 | __pipe_lock(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | count = 0; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 507 | buf = pipe->curbuf; |
| 508 | nrbufs = pipe->nrbufs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 509 | while (--nrbufs >= 0) { |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 510 | count += pipe->bufs[buf].len; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 511 | buf = (buf+1) & (pipe->buffers - 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | } |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 513 | __pipe_unlock(pipe); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 514 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 515 | return put_user(count, (int __user *)arg); |
| 516 | default: |
Will Deacon | 46ce341 | 2012-05-25 11:39:13 +0100 | [diff] [blame] | 517 | return -ENOIOCTLCMD; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 518 | } |
| 519 | } |
| 520 | |
| 521 | /* No kernel lock held - fine */ |
| 522 | static unsigned int |
| 523 | pipe_poll(struct file *filp, poll_table *wait) |
| 524 | { |
| 525 | unsigned int mask; |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 526 | struct pipe_inode_info *pipe = filp->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 527 | int nrbufs; |
| 528 | |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 529 | poll_wait(filp, &pipe->wait, wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | |
| 531 | /* Reading only -- no need for acquiring the semaphore. */ |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 532 | nrbufs = pipe->nrbufs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | mask = 0; |
| 534 | if (filp->f_mode & FMODE_READ) { |
| 535 | mask = (nrbufs > 0) ? POLLIN | POLLRDNORM : 0; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 536 | if (!pipe->writers && filp->f_version != pipe->w_counter) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | mask |= POLLHUP; |
| 538 | } |
| 539 | |
| 540 | if (filp->f_mode & FMODE_WRITE) { |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 541 | mask |= (nrbufs < pipe->buffers) ? POLLOUT | POLLWRNORM : 0; |
Pekka Enberg | 5e5d7a2 | 2005-09-06 15:17:48 -0700 | [diff] [blame] | 542 | /* |
| 543 | * Most Unices do not set POLLERR for FIFOs but on Linux they |
| 544 | * behave exactly like pipes for poll(). |
| 545 | */ |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 546 | if (!pipe->readers) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | mask |= POLLERR; |
| 548 | } |
| 549 | |
| 550 | return mask; |
| 551 | } |
| 552 | |
Linus Torvalds | b0d8d22 | 2013-12-02 09:44:51 -0800 | [diff] [blame] | 553 | static void put_pipe_info(struct inode *inode, struct pipe_inode_info *pipe) |
| 554 | { |
| 555 | int kill = 0; |
| 556 | |
| 557 | spin_lock(&inode->i_lock); |
| 558 | if (!--pipe->files) { |
| 559 | inode->i_pipe = NULL; |
| 560 | kill = 1; |
| 561 | } |
| 562 | spin_unlock(&inode->i_lock); |
| 563 | |
| 564 | if (kill) |
| 565 | free_pipe_info(pipe); |
| 566 | } |
| 567 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 568 | static int |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 569 | pipe_release(struct inode *inode, struct file *file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | { |
Linus Torvalds | b0d8d22 | 2013-12-02 09:44:51 -0800 | [diff] [blame] | 571 | struct pipe_inode_info *pipe = file->private_data; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 572 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 573 | __pipe_lock(pipe); |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 574 | if (file->f_mode & FMODE_READ) |
| 575 | pipe->readers--; |
| 576 | if (file->f_mode & FMODE_WRITE) |
| 577 | pipe->writers--; |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 578 | |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 579 | if (pipe->readers || pipe->writers) { |
Linus Torvalds | 28e58ee | 2011-01-20 16:21:59 -0800 | [diff] [blame] | 580 | 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] | 581 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); |
| 582 | kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | } |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 584 | __pipe_unlock(pipe); |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 585 | |
Linus Torvalds | b0d8d22 | 2013-12-02 09:44:51 -0800 | [diff] [blame] | 586 | put_pipe_info(inode, pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 587 | return 0; |
| 588 | } |
| 589 | |
| 590 | static int |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 591 | pipe_fasync(int fd, struct file *filp, int on) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 592 | { |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 593 | struct pipe_inode_info *pipe = filp->private_data; |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 594 | int retval = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 595 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 596 | __pipe_lock(pipe); |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 597 | if (filp->f_mode & FMODE_READ) |
| 598 | retval = fasync_helper(fd, filp, on, &pipe->fasync_readers); |
| 599 | if ((filp->f_mode & FMODE_WRITE) && retval >= 0) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 600 | retval = fasync_helper(fd, filp, on, &pipe->fasync_writers); |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 601 | if (retval < 0 && (filp->f_mode & FMODE_READ)) |
| 602 | /* this can happen only if on == T */ |
Oleg Nesterov | e5bc49b | 2009-03-12 14:31:28 -0700 | [diff] [blame] | 603 | fasync_helper(-1, filp, 0, &pipe->fasync_readers); |
| 604 | } |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 605 | __pipe_unlock(pipe); |
Jonathan Corbet | 60aa492 | 2009-02-01 14:52:56 -0700 | [diff] [blame] | 606 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 607 | } |
| 608 | |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 609 | static void account_pipe_buffers(struct pipe_inode_info *pipe, |
| 610 | unsigned long old, unsigned long new) |
| 611 | { |
| 612 | atomic_long_add(new - old, &pipe->user->pipe_bufs); |
| 613 | } |
| 614 | |
| 615 | static bool too_many_pipe_buffers_soft(struct user_struct *user) |
| 616 | { |
| 617 | return pipe_user_pages_soft && |
| 618 | atomic_long_read(&user->pipe_bufs) >= pipe_user_pages_soft; |
| 619 | } |
| 620 | |
| 621 | static bool too_many_pipe_buffers_hard(struct user_struct *user) |
| 622 | { |
| 623 | return pipe_user_pages_hard && |
| 624 | atomic_long_read(&user->pipe_bufs) >= pipe_user_pages_hard; |
| 625 | } |
| 626 | |
Al Viro | 7bee130 | 2013-03-21 11:04:15 -0400 | [diff] [blame] | 627 | struct pipe_inode_info *alloc_pipe_info(void) |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 628 | { |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 629 | struct pipe_inode_info *pipe; |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 630 | |
Vladimir Davydov | d86133b | 2016-07-26 15:24:33 -0700 | [diff] [blame^] | 631 | pipe = kzalloc(sizeof(struct pipe_inode_info), GFP_KERNEL_ACCOUNT); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 632 | if (pipe) { |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 633 | unsigned long pipe_bufs = PIPE_DEF_BUFFERS; |
| 634 | struct user_struct *user = get_current_user(); |
| 635 | |
| 636 | if (!too_many_pipe_buffers_hard(user)) { |
| 637 | if (too_many_pipe_buffers_soft(user)) |
| 638 | pipe_bufs = 1; |
Vladimir Davydov | d86133b | 2016-07-26 15:24:33 -0700 | [diff] [blame^] | 639 | pipe->bufs = kcalloc(pipe_bufs, |
| 640 | sizeof(struct pipe_buffer), |
| 641 | GFP_KERNEL_ACCOUNT); |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 642 | } |
| 643 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 644 | if (pipe->bufs) { |
| 645 | init_waitqueue_head(&pipe->wait); |
| 646 | pipe->r_counter = pipe->w_counter = 1; |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 647 | pipe->buffers = pipe_bufs; |
| 648 | pipe->user = user; |
| 649 | account_pipe_buffers(pipe, 0, pipe_bufs); |
Al Viro | 72b0d9a | 2013-03-21 02:32:24 -0400 | [diff] [blame] | 650 | mutex_init(&pipe->mutex); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 651 | return pipe; |
| 652 | } |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 653 | free_uid(user); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 654 | kfree(pipe); |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 655 | } |
| 656 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 657 | return NULL; |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 658 | } |
| 659 | |
Al Viro | 4b8a8f1 | 2013-03-21 11:06:46 -0400 | [diff] [blame] | 660 | void free_pipe_info(struct pipe_inode_info *pipe) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 661 | { |
| 662 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 663 | |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 664 | account_pipe_buffers(pipe, pipe->buffers, 0); |
| 665 | free_uid(pipe->user); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 666 | for (i = 0; i < pipe->buffers; i++) { |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 667 | struct pipe_buffer *buf = pipe->bufs + i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 668 | if (buf->ops) |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 669 | buf->ops->release(pipe, buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 670 | } |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 671 | if (pipe->tmp_page) |
| 672 | __free_page(pipe->tmp_page); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 673 | kfree(pipe->bufs); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 674 | kfree(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 675 | } |
| 676 | |
Eric Dumazet | fa3536c | 2006-03-26 01:37:24 -0800 | [diff] [blame] | 677 | static struct vfsmount *pipe_mnt __read_mostly; |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 678 | |
Eric Dumazet | c23fbb6 | 2007-05-08 00:26:18 -0700 | [diff] [blame] | 679 | /* |
| 680 | * pipefs_dname() is called from d_path(). |
| 681 | */ |
| 682 | static char *pipefs_dname(struct dentry *dentry, char *buffer, int buflen) |
| 683 | { |
| 684 | return dynamic_dname(dentry, buffer, buflen, "pipe:[%lu]", |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 685 | d_inode(dentry)->i_ino); |
Eric Dumazet | c23fbb6 | 2007-05-08 00:26:18 -0700 | [diff] [blame] | 686 | } |
| 687 | |
Al Viro | 3ba13d1 | 2009-02-20 06:02:22 +0000 | [diff] [blame] | 688 | static const struct dentry_operations pipefs_dentry_operations = { |
Eric Dumazet | c23fbb6 | 2007-05-08 00:26:18 -0700 | [diff] [blame] | 689 | .d_dname = pipefs_dname, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 690 | }; |
| 691 | |
| 692 | static struct inode * get_pipe_inode(void) |
| 693 | { |
Eric Dumazet | a209dfc | 2011-07-26 11:36:34 +0200 | [diff] [blame] | 694 | struct inode *inode = new_inode_pseudo(pipe_mnt->mnt_sb); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 695 | struct pipe_inode_info *pipe; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 696 | |
| 697 | if (!inode) |
| 698 | goto fail_inode; |
| 699 | |
Christoph Hellwig | 85fe402 | 2010-10-23 11:19:54 -0400 | [diff] [blame] | 700 | inode->i_ino = get_next_ino(); |
| 701 | |
Al Viro | 7bee130 | 2013-03-21 11:04:15 -0400 | [diff] [blame] | 702 | pipe = alloc_pipe_info(); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 703 | if (!pipe) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 704 | goto fail_iput; |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 705 | |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 706 | inode->i_pipe = pipe; |
| 707 | pipe->files = 2; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 708 | pipe->readers = pipe->writers = 1; |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 709 | inode->i_fop = &pipefifo_fops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 710 | |
| 711 | /* |
| 712 | * Mark the inode dirty from the very beginning, |
| 713 | * that way it will never be moved to the dirty |
| 714 | * list because "mark_inode_dirty()" will think |
| 715 | * that it already _is_ on the dirty list. |
| 716 | */ |
| 717 | inode->i_state = I_DIRTY; |
| 718 | inode->i_mode = S_IFIFO | S_IRUSR | S_IWUSR; |
David Howells | da9592e | 2008-11-14 10:39:05 +1100 | [diff] [blame] | 719 | inode->i_uid = current_fsuid(); |
| 720 | inode->i_gid = current_fsgid(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 721 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 722 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 723 | return inode; |
| 724 | |
| 725 | fail_iput: |
| 726 | iput(inode); |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 727 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 728 | fail_inode: |
| 729 | return NULL; |
| 730 | } |
| 731 | |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 732 | int create_pipe_files(struct file **res, int flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 733 | { |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 734 | int err; |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 735 | struct inode *inode = get_pipe_inode(); |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 736 | struct file *f; |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 737 | struct path path; |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 738 | static struct qstr name = { .name = "" }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 739 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 740 | if (!inode) |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 741 | return -ENFILE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 742 | |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 743 | err = -ENOMEM; |
Nick Piggin | 4b93688 | 2011-01-07 17:50:07 +1100 | [diff] [blame] | 744 | path.dentry = d_alloc_pseudo(pipe_mnt->mnt_sb, &name); |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 745 | if (!path.dentry) |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 746 | goto err_inode; |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 747 | path.mnt = mntget(pipe_mnt); |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 748 | |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 749 | d_instantiate(path.dentry, inode); |
Dave Hansen | 430e285 | 2008-02-15 14:37:26 -0800 | [diff] [blame] | 750 | |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 751 | f = alloc_file(&path, FMODE_WRITE, &pipefifo_fops); |
Eric Biggers | e9bb1f9 | 2015-10-17 16:26:08 -0500 | [diff] [blame] | 752 | if (IS_ERR(f)) { |
| 753 | err = PTR_ERR(f); |
Dave Hansen | 430e285 | 2008-02-15 14:37:26 -0800 | [diff] [blame] | 754 | goto err_dentry; |
Eric Biggers | e9bb1f9 | 2015-10-17 16:26:08 -0500 | [diff] [blame] | 755 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 756 | |
Linus Torvalds | 9883035 | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 757 | f->f_flags = O_WRONLY | (flags & (O_NONBLOCK | O_DIRECT)); |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 758 | f->private_data = inode->i_pipe; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 759 | |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 760 | res[0] = alloc_file(&path, FMODE_READ, &pipefifo_fops); |
Eric Biggers | e9bb1f9 | 2015-10-17 16:26:08 -0500 | [diff] [blame] | 761 | if (IS_ERR(res[0])) { |
| 762 | err = PTR_ERR(res[0]); |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 763 | goto err_file; |
Eric Biggers | e9bb1f9 | 2015-10-17 16:26:08 -0500 | [diff] [blame] | 764 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 765 | |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 766 | path_get(&path); |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 767 | res[0]->private_data = inode->i_pipe; |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 768 | res[0]->f_flags = O_RDONLY | (flags & O_NONBLOCK); |
| 769 | res[1] = f; |
| 770 | return 0; |
| 771 | |
| 772 | err_file: |
| 773 | put_filp(f); |
| 774 | err_dentry: |
Al Viro | 4b8a8f1 | 2013-03-21 11:06:46 -0400 | [diff] [blame] | 775 | free_pipe_info(inode->i_pipe); |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 776 | path_put(&path); |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 777 | return err; |
Al Viro | ed15243 | 2008-04-22 19:51:27 -0400 | [diff] [blame] | 778 | |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 779 | err_inode: |
Al Viro | 4b8a8f1 | 2013-03-21 11:06:46 -0400 | [diff] [blame] | 780 | free_pipe_info(inode->i_pipe); |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 781 | iput(inode); |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 782 | return err; |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 783 | } |
| 784 | |
Al Viro | 5b249b1 | 2012-08-19 12:17:29 -0400 | [diff] [blame] | 785 | static int __do_pipe_flags(int *fd, struct file **files, int flags) |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 786 | { |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 787 | int error; |
| 788 | int fdw, fdr; |
| 789 | |
Linus Torvalds | 9883035 | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 790 | if (flags & ~(O_CLOEXEC | O_NONBLOCK | O_DIRECT)) |
Ulrich Drepper | ed8cae8 | 2008-07-23 21:29:30 -0700 | [diff] [blame] | 791 | return -EINVAL; |
| 792 | |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 793 | error = create_pipe_files(files, flags); |
| 794 | if (error) |
| 795 | return error; |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 796 | |
Ulrich Drepper | ed8cae8 | 2008-07-23 21:29:30 -0700 | [diff] [blame] | 797 | error = get_unused_fd_flags(flags); |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 798 | if (error < 0) |
| 799 | goto err_read_pipe; |
| 800 | fdr = error; |
| 801 | |
Ulrich Drepper | ed8cae8 | 2008-07-23 21:29:30 -0700 | [diff] [blame] | 802 | error = get_unused_fd_flags(flags); |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 803 | if (error < 0) |
| 804 | goto err_fdr; |
| 805 | fdw = error; |
| 806 | |
Al Viro | 157cf64 | 2008-12-14 04:57:47 -0500 | [diff] [blame] | 807 | audit_fd_pair(fdr, fdw); |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 808 | fd[0] = fdr; |
| 809 | fd[1] = fdw; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 810 | return 0; |
| 811 | |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 812 | err_fdr: |
| 813 | put_unused_fd(fdr); |
| 814 | err_read_pipe: |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 815 | fput(files[0]); |
| 816 | fput(files[1]); |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 817 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 818 | } |
| 819 | |
Al Viro | 5b249b1 | 2012-08-19 12:17:29 -0400 | [diff] [blame] | 820 | int do_pipe_flags(int *fd, int flags) |
| 821 | { |
| 822 | struct file *files[2]; |
| 823 | int error = __do_pipe_flags(fd, files, flags); |
| 824 | if (!error) { |
| 825 | fd_install(fd[0], files[0]); |
| 826 | fd_install(fd[1], files[1]); |
| 827 | } |
| 828 | return error; |
| 829 | } |
| 830 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 831 | /* |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 832 | * sys_pipe() is the normal C calling standard for creating |
| 833 | * a pipe. It's not the way Unix traditionally does this, though. |
| 834 | */ |
Heiko Carstens | d4e8204 | 2009-01-14 14:14:34 +0100 | [diff] [blame] | 835 | SYSCALL_DEFINE2(pipe2, int __user *, fildes, int, flags) |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 836 | { |
Al Viro | 5b249b1 | 2012-08-19 12:17:29 -0400 | [diff] [blame] | 837 | struct file *files[2]; |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 838 | int fd[2]; |
| 839 | int error; |
| 840 | |
Al Viro | 5b249b1 | 2012-08-19 12:17:29 -0400 | [diff] [blame] | 841 | error = __do_pipe_flags(fd, files, flags); |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 842 | if (!error) { |
Al Viro | 5b249b1 | 2012-08-19 12:17:29 -0400 | [diff] [blame] | 843 | if (unlikely(copy_to_user(fildes, fd, sizeof(fd)))) { |
| 844 | fput(files[0]); |
| 845 | fput(files[1]); |
| 846 | put_unused_fd(fd[0]); |
| 847 | put_unused_fd(fd[1]); |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 848 | error = -EFAULT; |
Al Viro | 5b249b1 | 2012-08-19 12:17:29 -0400 | [diff] [blame] | 849 | } else { |
| 850 | fd_install(fd[0], files[0]); |
| 851 | fd_install(fd[1], files[1]); |
Ulrich Drepper | ba719ba | 2008-05-06 20:42:38 -0700 | [diff] [blame] | 852 | } |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 853 | } |
| 854 | return error; |
| 855 | } |
| 856 | |
Heiko Carstens | 2b66421 | 2009-01-14 14:14:35 +0100 | [diff] [blame] | 857 | SYSCALL_DEFINE1(pipe, int __user *, fildes) |
Ulrich Drepper | ed8cae8 | 2008-07-23 21:29:30 -0700 | [diff] [blame] | 858 | { |
| 859 | return sys_pipe2(fildes, 0); |
| 860 | } |
| 861 | |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 862 | 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] | 863 | { |
| 864 | int cur = *cnt; |
| 865 | |
| 866 | while (cur == *cnt) { |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 867 | pipe_wait(pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 868 | if (signal_pending(current)) |
| 869 | break; |
| 870 | } |
| 871 | return cur == *cnt ? -ERESTARTSYS : 0; |
| 872 | } |
| 873 | |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 874 | static void wake_up_partner(struct pipe_inode_info *pipe) |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 875 | { |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 876 | wake_up_interruptible(&pipe->wait); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 877 | } |
| 878 | |
| 879 | static int fifo_open(struct inode *inode, struct file *filp) |
| 880 | { |
| 881 | struct pipe_inode_info *pipe; |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 882 | bool is_pipe = inode->i_sb->s_magic == PIPEFS_MAGIC; |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 883 | int ret; |
| 884 | |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 885 | filp->f_version = 0; |
| 886 | |
| 887 | spin_lock(&inode->i_lock); |
| 888 | if (inode->i_pipe) { |
| 889 | pipe = inode->i_pipe; |
| 890 | pipe->files++; |
| 891 | spin_unlock(&inode->i_lock); |
| 892 | } else { |
| 893 | spin_unlock(&inode->i_lock); |
Al Viro | 7bee130 | 2013-03-21 11:04:15 -0400 | [diff] [blame] | 894 | pipe = alloc_pipe_info(); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 895 | if (!pipe) |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 896 | return -ENOMEM; |
| 897 | pipe->files = 1; |
| 898 | spin_lock(&inode->i_lock); |
| 899 | if (unlikely(inode->i_pipe)) { |
| 900 | inode->i_pipe->files++; |
| 901 | spin_unlock(&inode->i_lock); |
Al Viro | 4b8a8f1 | 2013-03-21 11:06:46 -0400 | [diff] [blame] | 902 | free_pipe_info(pipe); |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 903 | pipe = inode->i_pipe; |
| 904 | } else { |
| 905 | inode->i_pipe = pipe; |
| 906 | spin_unlock(&inode->i_lock); |
| 907 | } |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 908 | } |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 909 | filp->private_data = pipe; |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 910 | /* OK, we have a pipe and it's pinned down */ |
| 911 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 912 | __pipe_lock(pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 913 | |
| 914 | /* We can only do regular read/write on fifos */ |
| 915 | filp->f_mode &= (FMODE_READ | FMODE_WRITE); |
| 916 | |
| 917 | switch (filp->f_mode) { |
| 918 | case FMODE_READ: |
| 919 | /* |
| 920 | * O_RDONLY |
| 921 | * POSIX.1 says that O_NONBLOCK means return with the FIFO |
| 922 | * opened, even when there is no process writing the FIFO. |
| 923 | */ |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 924 | pipe->r_counter++; |
| 925 | if (pipe->readers++ == 0) |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 926 | wake_up_partner(pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 927 | |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 928 | if (!is_pipe && !pipe->writers) { |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 929 | if ((filp->f_flags & O_NONBLOCK)) { |
| 930 | /* suppress POLLHUP until we have |
| 931 | * seen a writer */ |
| 932 | filp->f_version = pipe->w_counter; |
| 933 | } else { |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 934 | if (wait_for_partner(pipe, &pipe->w_counter)) |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 935 | goto err_rd; |
| 936 | } |
| 937 | } |
| 938 | break; |
| 939 | |
| 940 | case FMODE_WRITE: |
| 941 | /* |
| 942 | * O_WRONLY |
| 943 | * POSIX.1 says that O_NONBLOCK means return -1 with |
| 944 | * errno=ENXIO when there is no process reading the FIFO. |
| 945 | */ |
| 946 | ret = -ENXIO; |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 947 | if (!is_pipe && (filp->f_flags & O_NONBLOCK) && !pipe->readers) |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 948 | goto err; |
| 949 | |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 950 | pipe->w_counter++; |
| 951 | if (!pipe->writers++) |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 952 | wake_up_partner(pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 953 | |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 954 | if (!is_pipe && !pipe->readers) { |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 955 | if (wait_for_partner(pipe, &pipe->r_counter)) |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 956 | goto err_wr; |
| 957 | } |
| 958 | break; |
| 959 | |
| 960 | case FMODE_READ | FMODE_WRITE: |
| 961 | /* |
| 962 | * O_RDWR |
| 963 | * POSIX.1 leaves this case "undefined" when O_NONBLOCK is set. |
| 964 | * This implementation will NEVER block on a O_RDWR open, since |
| 965 | * the process can at least talk to itself. |
| 966 | */ |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 967 | |
| 968 | pipe->readers++; |
| 969 | pipe->writers++; |
| 970 | pipe->r_counter++; |
| 971 | pipe->w_counter++; |
| 972 | if (pipe->readers == 1 || pipe->writers == 1) |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 973 | wake_up_partner(pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 974 | break; |
| 975 | |
| 976 | default: |
| 977 | ret = -EINVAL; |
| 978 | goto err; |
| 979 | } |
| 980 | |
| 981 | /* Ok! */ |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 982 | __pipe_unlock(pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 983 | return 0; |
| 984 | |
| 985 | err_rd: |
| 986 | if (!--pipe->readers) |
| 987 | wake_up_interruptible(&pipe->wait); |
| 988 | ret = -ERESTARTSYS; |
| 989 | goto err; |
| 990 | |
| 991 | err_wr: |
| 992 | if (!--pipe->writers) |
| 993 | wake_up_interruptible(&pipe->wait); |
| 994 | ret = -ERESTARTSYS; |
| 995 | goto err; |
| 996 | |
| 997 | err: |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 998 | __pipe_unlock(pipe); |
Linus Torvalds | b0d8d22 | 2013-12-02 09:44:51 -0800 | [diff] [blame] | 999 | |
| 1000 | put_pipe_info(inode, pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 1001 | return ret; |
| 1002 | } |
| 1003 | |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 1004 | const struct file_operations pipefifo_fops = { |
| 1005 | .open = fifo_open, |
| 1006 | .llseek = no_llseek, |
Al Viro | fb9096a | 2014-04-02 19:56:54 -0400 | [diff] [blame] | 1007 | .read_iter = pipe_read, |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 1008 | .write_iter = pipe_write, |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 1009 | .poll = pipe_poll, |
| 1010 | .unlocked_ioctl = pipe_ioctl, |
| 1011 | .release = pipe_release, |
| 1012 | .fasync = pipe_fasync, |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 1013 | }; |
| 1014 | |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 1015 | /* |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1016 | * Allocate a new array of pipe buffers and copy the info over. Returns the |
| 1017 | * pipe size if successful, or return -ERROR on error. |
| 1018 | */ |
Jens Axboe | b9598db | 2010-05-24 19:34:43 +0200 | [diff] [blame] | 1019 | 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] | 1020 | { |
| 1021 | struct pipe_buffer *bufs; |
| 1022 | |
| 1023 | /* |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1024 | * We can shrink the pipe, if arg >= pipe->nrbufs. Since we don't |
| 1025 | * expect a lot of shrink+grow operations, just free and allocate |
| 1026 | * again like we would do for growing. If the pipe currently |
| 1027 | * contains more buffers than arg, then return busy. |
| 1028 | */ |
Jens Axboe | b9598db | 2010-05-24 19:34:43 +0200 | [diff] [blame] | 1029 | if (nr_pages < pipe->nrbufs) |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1030 | return -EBUSY; |
| 1031 | |
Vladimir Davydov | d86133b | 2016-07-26 15:24:33 -0700 | [diff] [blame^] | 1032 | bufs = kcalloc(nr_pages, sizeof(*bufs), |
| 1033 | GFP_KERNEL_ACCOUNT | __GFP_NOWARN); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1034 | if (unlikely(!bufs)) |
| 1035 | return -ENOMEM; |
| 1036 | |
| 1037 | /* |
| 1038 | * The pipe array wraps around, so just start the new one at zero |
| 1039 | * and adjust the indexes. |
| 1040 | */ |
| 1041 | if (pipe->nrbufs) { |
Miklos Szeredi | 1d862f4 | 2010-06-08 16:28:45 +0200 | [diff] [blame] | 1042 | unsigned int tail; |
| 1043 | unsigned int head; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1044 | |
Miklos Szeredi | 1d862f4 | 2010-06-08 16:28:45 +0200 | [diff] [blame] | 1045 | tail = pipe->curbuf + pipe->nrbufs; |
| 1046 | if (tail < pipe->buffers) |
| 1047 | tail = 0; |
| 1048 | else |
| 1049 | tail &= (pipe->buffers - 1); |
| 1050 | |
| 1051 | head = pipe->nrbufs - tail; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1052 | if (head) |
| 1053 | memcpy(bufs, pipe->bufs + pipe->curbuf, head * sizeof(struct pipe_buffer)); |
| 1054 | if (tail) |
Miklos Szeredi | 1d862f4 | 2010-06-08 16:28:45 +0200 | [diff] [blame] | 1055 | memcpy(bufs + head, pipe->bufs, tail * sizeof(struct pipe_buffer)); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1056 | } |
| 1057 | |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 1058 | account_pipe_buffers(pipe, pipe->buffers, nr_pages); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1059 | pipe->curbuf = 0; |
| 1060 | kfree(pipe->bufs); |
| 1061 | pipe->bufs = bufs; |
Jens Axboe | b9598db | 2010-05-24 19:34:43 +0200 | [diff] [blame] | 1062 | pipe->buffers = nr_pages; |
| 1063 | return nr_pages * PAGE_SIZE; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1064 | } |
| 1065 | |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 1066 | /* |
| 1067 | * Currently we rely on the pipe array holding a power-of-2 number |
| 1068 | * of pages. |
| 1069 | */ |
| 1070 | static inline unsigned int round_pipe_size(unsigned int size) |
| 1071 | { |
| 1072 | unsigned long nr_pages; |
| 1073 | |
| 1074 | nr_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 1075 | return roundup_pow_of_two(nr_pages) << PAGE_SHIFT; |
| 1076 | } |
| 1077 | |
| 1078 | /* |
| 1079 | * This should work even if CONFIG_PROC_FS isn't set, as proc_dointvec_minmax |
| 1080 | * will return an error. |
| 1081 | */ |
| 1082 | int pipe_proc_fn(struct ctl_table *table, int write, void __user *buf, |
| 1083 | size_t *lenp, loff_t *ppos) |
| 1084 | { |
| 1085 | int ret; |
| 1086 | |
| 1087 | ret = proc_dointvec_minmax(table, write, buf, lenp, ppos); |
| 1088 | if (ret < 0 || !write) |
| 1089 | return ret; |
| 1090 | |
| 1091 | pipe_max_size = round_pipe_size(pipe_max_size); |
| 1092 | return ret; |
| 1093 | } |
| 1094 | |
Linus Torvalds | 7208364 | 2010-11-28 16:27:19 -0800 | [diff] [blame] | 1095 | /* |
| 1096 | * After the inode slimming patch, i_pipe/i_bdev/i_cdev share the same |
| 1097 | * location, so checking ->i_pipe is not enough to verify that this is a |
| 1098 | * pipe. |
| 1099 | */ |
| 1100 | struct pipe_inode_info *get_pipe_info(struct file *file) |
| 1101 | { |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 1102 | return file->f_op == &pipefifo_fops ? file->private_data : NULL; |
Linus Torvalds | 7208364 | 2010-11-28 16:27:19 -0800 | [diff] [blame] | 1103 | } |
| 1104 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1105 | long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg) |
| 1106 | { |
| 1107 | struct pipe_inode_info *pipe; |
| 1108 | long ret; |
| 1109 | |
Linus Torvalds | c66fb34 | 2010-11-28 14:09:57 -0800 | [diff] [blame] | 1110 | pipe = get_pipe_info(file); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1111 | if (!pipe) |
| 1112 | return -EBADF; |
| 1113 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 1114 | __pipe_lock(pipe); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1115 | |
| 1116 | switch (cmd) { |
Jens Axboe | b9598db | 2010-05-24 19:34:43 +0200 | [diff] [blame] | 1117 | case F_SETPIPE_SZ: { |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 1118 | unsigned int size, nr_pages; |
Jens Axboe | b9598db | 2010-05-24 19:34:43 +0200 | [diff] [blame] | 1119 | |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 1120 | size = round_pipe_size(arg); |
| 1121 | nr_pages = size >> PAGE_SHIFT; |
Jens Axboe | b9598db | 2010-05-24 19:34:43 +0200 | [diff] [blame] | 1122 | |
Miklos Szeredi | 6db40cf | 2010-06-09 09:27:57 +0200 | [diff] [blame] | 1123 | ret = -EINVAL; |
| 1124 | if (!nr_pages) |
| 1125 | goto out; |
| 1126 | |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 1127 | if (!capable(CAP_SYS_RESOURCE) && size > pipe_max_size) { |
Jens Axboe | b4ca761 | 2010-06-01 12:42:12 +0200 | [diff] [blame] | 1128 | ret = -EPERM; |
Julia Lawall | cc967be | 2010-05-26 17:54:39 +0200 | [diff] [blame] | 1129 | goto out; |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 1130 | } else if ((too_many_pipe_buffers_hard(pipe->user) || |
| 1131 | too_many_pipe_buffers_soft(pipe->user)) && |
| 1132 | !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN)) { |
| 1133 | ret = -EPERM; |
| 1134 | goto out; |
Julia Lawall | cc967be | 2010-05-26 17:54:39 +0200 | [diff] [blame] | 1135 | } |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 1136 | ret = pipe_set_size(pipe, nr_pages); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1137 | break; |
Jens Axboe | b9598db | 2010-05-24 19:34:43 +0200 | [diff] [blame] | 1138 | } |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1139 | case F_GETPIPE_SZ: |
Jens Axboe | b9598db | 2010-05-24 19:34:43 +0200 | [diff] [blame] | 1140 | ret = pipe->buffers * PAGE_SIZE; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1141 | break; |
| 1142 | default: |
| 1143 | ret = -EINVAL; |
| 1144 | break; |
| 1145 | } |
| 1146 | |
Julia Lawall | cc967be | 2010-05-26 17:54:39 +0200 | [diff] [blame] | 1147 | out: |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 1148 | __pipe_unlock(pipe); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1149 | return ret; |
| 1150 | } |
| 1151 | |
Nick Piggin | ff0c7d1 | 2011-01-07 17:49:50 +1100 | [diff] [blame] | 1152 | static const struct super_operations pipefs_ops = { |
| 1153 | .destroy_inode = free_inode_nonrcu, |
Pavel Emelyanov | d70ef97 | 2011-10-31 17:10:04 -0700 | [diff] [blame] | 1154 | .statfs = simple_statfs, |
Nick Piggin | ff0c7d1 | 2011-01-07 17:49:50 +1100 | [diff] [blame] | 1155 | }; |
| 1156 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1157 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1158 | * pipefs should _never_ be mounted by userland - too much of security hassle, |
| 1159 | * no real gain from having the whole whorehouse mounted. So we don't need |
| 1160 | * any operations on the root directory. However, we need a non-trivial |
| 1161 | * d_name - pipe: will go nicely and kill the special-casing in procfs. |
| 1162 | */ |
Al Viro | 51139ad | 2010-07-25 23:47:46 +0400 | [diff] [blame] | 1163 | static struct dentry *pipefs_mount(struct file_system_type *fs_type, |
| 1164 | int flags, const char *dev_name, void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1165 | { |
Al Viro | c74a1cb | 2011-01-12 16:59:34 -0500 | [diff] [blame] | 1166 | return mount_pseudo(fs_type, "pipe:", &pipefs_ops, |
| 1167 | &pipefs_dentry_operations, PIPEFS_MAGIC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1168 | } |
| 1169 | |
| 1170 | static struct file_system_type pipe_fs_type = { |
| 1171 | .name = "pipefs", |
Al Viro | 51139ad | 2010-07-25 23:47:46 +0400 | [diff] [blame] | 1172 | .mount = pipefs_mount, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1173 | .kill_sb = kill_anon_super, |
| 1174 | }; |
| 1175 | |
| 1176 | static int __init init_pipe_fs(void) |
| 1177 | { |
| 1178 | int err = register_filesystem(&pipe_fs_type); |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 1179 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1180 | if (!err) { |
| 1181 | pipe_mnt = kern_mount(&pipe_fs_type); |
| 1182 | if (IS_ERR(pipe_mnt)) { |
| 1183 | err = PTR_ERR(pipe_mnt); |
| 1184 | unregister_filesystem(&pipe_fs_type); |
| 1185 | } |
| 1186 | } |
| 1187 | return err; |
| 1188 | } |
| 1189 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1190 | fs_initcall(init_pipe_fs); |