Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1 | /* |
| 2 | * "splice": joining two ropes together by interweaving their strands. |
| 3 | * |
| 4 | * This is the "extended pipe" functionality, where a pipe is used as |
| 5 | * an arbitrary in-memory buffer. Think of a pipe as a small kernel |
| 6 | * buffer that you can use to transfer data from one end to the other. |
| 7 | * |
| 8 | * The traditional unix read/write is extended with a "splice()" operation |
| 9 | * that transfers data buffers to or from a pipe buffer. |
| 10 | * |
| 11 | * Named by Larry McVoy, original implementation from Linus, extended by |
Jens Axboe | c2058e0 | 2006-04-11 13:56:34 +0200 | [diff] [blame] | 12 | * Jens to support splicing to files, network, direct splicing, etc and |
| 13 | * fixing lots of bugs. |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 14 | * |
Jens Axboe | 0fe2347 | 2006-09-04 15:41:16 +0200 | [diff] [blame] | 15 | * Copyright (C) 2005-2006 Jens Axboe <axboe@kernel.dk> |
Jens Axboe | c2058e0 | 2006-04-11 13:56:34 +0200 | [diff] [blame] | 16 | * Copyright (C) 2005-2006 Linus Torvalds <torvalds@osdl.org> |
| 17 | * Copyright (C) 2006 Ingo Molnar <mingo@elte.hu> |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 18 | * |
| 19 | */ |
| 20 | #include <linux/fs.h> |
| 21 | #include <linux/file.h> |
| 22 | #include <linux/pagemap.h> |
Jens Axboe | d6b29d7 | 2007-06-04 09:59:47 +0200 | [diff] [blame] | 23 | #include <linux/splice.h> |
KAMEZAWA Hiroyuki | 08e552c | 2009-01-07 18:08:01 -0800 | [diff] [blame] | 24 | #include <linux/memcontrol.h> |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 25 | #include <linux/mm_inline.h> |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 26 | #include <linux/swap.h> |
Jens Axboe | 4f6f0bd | 2006-04-02 23:04:46 +0200 | [diff] [blame] | 27 | #include <linux/writeback.h> |
Paul Gortmaker | 630d9c4 | 2011-11-16 23:57:37 -0500 | [diff] [blame] | 28 | #include <linux/export.h> |
Jens Axboe | 4f6f0bd | 2006-04-02 23:04:46 +0200 | [diff] [blame] | 29 | #include <linux/syscalls.h> |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 30 | #include <linux/uio.h> |
James Morris | 29ce205 | 2007-07-13 11:44:32 +0200 | [diff] [blame] | 31 | #include <linux/security.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 32 | #include <linux/gfp.h> |
Eric Dumazet | 35f9c09 | 2012-04-05 03:05:35 +0000 | [diff] [blame] | 33 | #include <linux/socket.h> |
Al Viro | 76b021d | 2013-03-02 10:19:56 -0500 | [diff] [blame] | 34 | #include <linux/compat.h> |
Al Viro | 06ae43f | 2013-03-20 13:19:30 -0400 | [diff] [blame] | 35 | #include "internal.h" |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 36 | |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 37 | /* |
| 38 | * Attempt to steal a page from a pipe buffer. This should perhaps go into |
| 39 | * a vm helper function, it's already simplified quite a bit by the |
| 40 | * addition of remove_mapping(). If success is returned, the caller may |
| 41 | * attempt to reuse this page for another destination. |
| 42 | */ |
Jens Axboe | 76ad4d1 | 2006-05-03 10:41:33 +0200 | [diff] [blame] | 43 | static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe, |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 44 | struct pipe_buffer *buf) |
| 45 | { |
| 46 | struct page *page = buf->page; |
Jens Axboe | 9e94cd4 | 2006-06-20 15:01:12 +0200 | [diff] [blame] | 47 | struct address_space *mapping; |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 48 | |
Jens Axboe | 9e0267c | 2006-04-19 15:57:31 +0200 | [diff] [blame] | 49 | lock_page(page); |
| 50 | |
Jens Axboe | 9e94cd4 | 2006-06-20 15:01:12 +0200 | [diff] [blame] | 51 | mapping = page_mapping(page); |
| 52 | if (mapping) { |
| 53 | WARN_ON(!PageUptodate(page)); |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 54 | |
Jens Axboe | 9e94cd4 | 2006-06-20 15:01:12 +0200 | [diff] [blame] | 55 | /* |
| 56 | * At least for ext2 with nobh option, we need to wait on |
| 57 | * writeback completing on this page, since we'll remove it |
| 58 | * from the pagecache. Otherwise truncate wont wait on the |
| 59 | * page, allowing the disk blocks to be reused by someone else |
| 60 | * before we actually wrote our data to them. fs corruption |
| 61 | * ensues. |
| 62 | */ |
| 63 | wait_on_page_writeback(page); |
Jens Axboe | ad8d6f0 | 2006-04-02 23:10:32 +0200 | [diff] [blame] | 64 | |
David Howells | 266cf65 | 2009-04-03 16:42:36 +0100 | [diff] [blame] | 65 | if (page_has_private(page) && |
| 66 | !try_to_release_page(page, GFP_KERNEL)) |
Jens Axboe | ca39d65 | 2008-05-20 21:27:41 +0200 | [diff] [blame] | 67 | goto out_unlock; |
Jens Axboe | 4f6f0bd | 2006-04-02 23:04:46 +0200 | [diff] [blame] | 68 | |
Jens Axboe | 9e94cd4 | 2006-06-20 15:01:12 +0200 | [diff] [blame] | 69 | /* |
| 70 | * If we succeeded in removing the mapping, set LRU flag |
| 71 | * and return good. |
| 72 | */ |
| 73 | if (remove_mapping(mapping, page)) { |
| 74 | buf->flags |= PIPE_BUF_FLAG_LRU; |
| 75 | return 0; |
| 76 | } |
Jens Axboe | 9e0267c | 2006-04-19 15:57:31 +0200 | [diff] [blame] | 77 | } |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 78 | |
Jens Axboe | 9e94cd4 | 2006-06-20 15:01:12 +0200 | [diff] [blame] | 79 | /* |
| 80 | * Raced with truncate or failed to remove page from current |
| 81 | * address space, unlock and return failure. |
| 82 | */ |
Jens Axboe | ca39d65 | 2008-05-20 21:27:41 +0200 | [diff] [blame] | 83 | out_unlock: |
Jens Axboe | 9e94cd4 | 2006-06-20 15:01:12 +0200 | [diff] [blame] | 84 | unlock_page(page); |
| 85 | return 1; |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 86 | } |
| 87 | |
Jens Axboe | 76ad4d1 | 2006-05-03 10:41:33 +0200 | [diff] [blame] | 88 | static void page_cache_pipe_buf_release(struct pipe_inode_info *pipe, |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 89 | struct pipe_buffer *buf) |
| 90 | { |
| 91 | page_cache_release(buf->page); |
Jens Axboe | 1432873 | 2006-05-03 10:35:26 +0200 | [diff] [blame] | 92 | buf->flags &= ~PIPE_BUF_FLAG_LRU; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 93 | } |
| 94 | |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 95 | /* |
| 96 | * Check whether the contents of buf is OK to access. Since the content |
| 97 | * is a page cache page, IO may be in flight. |
| 98 | */ |
Jens Axboe | cac36bb0 | 2007-06-14 13:10:48 +0200 | [diff] [blame] | 99 | static int page_cache_pipe_buf_confirm(struct pipe_inode_info *pipe, |
| 100 | struct pipe_buffer *buf) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 101 | { |
| 102 | struct page *page = buf->page; |
Jens Axboe | 49d0b21 | 2006-04-10 09:04:41 +0200 | [diff] [blame] | 103 | int err; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 104 | |
| 105 | if (!PageUptodate(page)) { |
Jens Axboe | 49d0b21 | 2006-04-10 09:04:41 +0200 | [diff] [blame] | 106 | lock_page(page); |
| 107 | |
| 108 | /* |
| 109 | * Page got truncated/unhashed. This will cause a 0-byte |
Ingo Molnar | 73d62d8 | 2006-04-11 13:57:21 +0200 | [diff] [blame] | 110 | * splice, if this is the first page. |
Jens Axboe | 49d0b21 | 2006-04-10 09:04:41 +0200 | [diff] [blame] | 111 | */ |
| 112 | if (!page->mapping) { |
| 113 | err = -ENODATA; |
| 114 | goto error; |
| 115 | } |
| 116 | |
| 117 | /* |
Ingo Molnar | 73d62d8 | 2006-04-11 13:57:21 +0200 | [diff] [blame] | 118 | * Uh oh, read-error from disk. |
Jens Axboe | 49d0b21 | 2006-04-10 09:04:41 +0200 | [diff] [blame] | 119 | */ |
| 120 | if (!PageUptodate(page)) { |
| 121 | err = -EIO; |
| 122 | goto error; |
| 123 | } |
| 124 | |
| 125 | /* |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 126 | * Page is ok afterall, we are done. |
Jens Axboe | 49d0b21 | 2006-04-10 09:04:41 +0200 | [diff] [blame] | 127 | */ |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 128 | unlock_page(page); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 129 | } |
| 130 | |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 131 | return 0; |
Jens Axboe | 49d0b21 | 2006-04-10 09:04:41 +0200 | [diff] [blame] | 132 | error: |
| 133 | unlock_page(page); |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 134 | return err; |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 135 | } |
| 136 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 137 | const struct pipe_buf_operations page_cache_pipe_buf_ops = { |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 138 | .can_merge = 0, |
Jens Axboe | cac36bb0 | 2007-06-14 13:10:48 +0200 | [diff] [blame] | 139 | .confirm = page_cache_pipe_buf_confirm, |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 140 | .release = page_cache_pipe_buf_release, |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 141 | .steal = page_cache_pipe_buf_steal, |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 142 | .get = generic_pipe_buf_get, |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 143 | }; |
| 144 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 145 | static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe, |
| 146 | struct pipe_buffer *buf) |
| 147 | { |
Jens Axboe | 7afa6fd | 2006-05-01 20:02:33 +0200 | [diff] [blame] | 148 | if (!(buf->flags & PIPE_BUF_FLAG_GIFT)) |
| 149 | return 1; |
| 150 | |
Jens Axboe | 1432873 | 2006-05-03 10:35:26 +0200 | [diff] [blame] | 151 | buf->flags |= PIPE_BUF_FLAG_LRU; |
Jens Axboe | 330ab71 | 2006-05-02 15:29:57 +0200 | [diff] [blame] | 152 | return generic_pipe_buf_steal(pipe, buf); |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 153 | } |
| 154 | |
Eric Dumazet | d4c3cca | 2006-12-13 00:34:04 -0800 | [diff] [blame] | 155 | static const struct pipe_buf_operations user_page_pipe_buf_ops = { |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 156 | .can_merge = 0, |
Jens Axboe | cac36bb0 | 2007-06-14 13:10:48 +0200 | [diff] [blame] | 157 | .confirm = generic_pipe_buf_confirm, |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 158 | .release = page_cache_pipe_buf_release, |
| 159 | .steal = user_page_pipe_buf_steal, |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 160 | .get = generic_pipe_buf_get, |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 161 | }; |
| 162 | |
Namhyung Kim | 825cdcb | 2011-05-23 19:58:53 +0200 | [diff] [blame] | 163 | static void wakeup_pipe_readers(struct pipe_inode_info *pipe) |
| 164 | { |
| 165 | smp_mb(); |
| 166 | if (waitqueue_active(&pipe->wait)) |
| 167 | wake_up_interruptible(&pipe->wait); |
| 168 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); |
| 169 | } |
| 170 | |
Jens Axboe | 932cc6d | 2007-06-21 13:10:21 +0200 | [diff] [blame] | 171 | /** |
| 172 | * splice_to_pipe - fill passed data into a pipe |
| 173 | * @pipe: pipe to fill |
| 174 | * @spd: data to fill |
| 175 | * |
| 176 | * Description: |
Randy Dunlap | 79685b8 | 2007-07-27 08:08:51 +0200 | [diff] [blame] | 177 | * @spd contains a map of pages and len/offset tuples, along with |
Jens Axboe | 932cc6d | 2007-06-21 13:10:21 +0200 | [diff] [blame] | 178 | * the struct pipe_buf_operations associated with these pages. This |
| 179 | * function will link that data to the pipe. |
| 180 | * |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 181 | */ |
Jens Axboe | d6b29d7 | 2007-06-04 09:59:47 +0200 | [diff] [blame] | 182 | ssize_t splice_to_pipe(struct pipe_inode_info *pipe, |
| 183 | struct splice_pipe_desc *spd) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 184 | { |
Jens Axboe | 00de00b | 2007-06-15 13:14:22 +0200 | [diff] [blame] | 185 | unsigned int spd_pages = spd->nr_pages; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 186 | int ret, do_wakeup, page_nr; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 187 | |
| 188 | ret = 0; |
| 189 | do_wakeup = 0; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 190 | page_nr = 0; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 191 | |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 192 | pipe_lock(pipe); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 193 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 194 | for (;;) { |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 195 | if (!pipe->readers) { |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 196 | send_sig(SIGPIPE, current, 0); |
| 197 | if (!ret) |
| 198 | ret = -EPIPE; |
| 199 | break; |
| 200 | } |
| 201 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 202 | if (pipe->nrbufs < pipe->buffers) { |
| 203 | int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 204 | struct pipe_buffer *buf = pipe->bufs + newbuf; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 205 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 206 | buf->page = spd->pages[page_nr]; |
| 207 | buf->offset = spd->partial[page_nr].offset; |
| 208 | buf->len = spd->partial[page_nr].len; |
Jens Axboe | 497f962 | 2007-06-11 12:00:45 +0200 | [diff] [blame] | 209 | buf->private = spd->partial[page_nr].private; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 210 | buf->ops = spd->ops; |
Jens Axboe | 7afa6fd | 2006-05-01 20:02:33 +0200 | [diff] [blame] | 211 | if (spd->flags & SPLICE_F_GIFT) |
| 212 | buf->flags |= PIPE_BUF_FLAG_GIFT; |
| 213 | |
Jens Axboe | 6f767b0 | 2006-04-11 13:53:56 +0200 | [diff] [blame] | 214 | pipe->nrbufs++; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 215 | page_nr++; |
| 216 | ret += buf->len; |
| 217 | |
Al Viro | 6447a3c | 2013-03-21 11:01:38 -0400 | [diff] [blame] | 218 | if (pipe->files) |
Jens Axboe | 6f767b0 | 2006-04-11 13:53:56 +0200 | [diff] [blame] | 219 | do_wakeup = 1; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 220 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 221 | if (!--spd->nr_pages) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 222 | break; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 223 | if (pipe->nrbufs < pipe->buffers) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 224 | continue; |
| 225 | |
| 226 | break; |
| 227 | } |
| 228 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 229 | if (spd->flags & SPLICE_F_NONBLOCK) { |
Linus Torvalds | 29e3509 | 2006-04-02 12:46:35 -0700 | [diff] [blame] | 230 | if (!ret) |
| 231 | ret = -EAGAIN; |
| 232 | break; |
| 233 | } |
| 234 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 235 | if (signal_pending(current)) { |
| 236 | if (!ret) |
| 237 | ret = -ERESTARTSYS; |
| 238 | break; |
| 239 | } |
| 240 | |
| 241 | if (do_wakeup) { |
Jens Axboe | c0bd1f6 | 2006-04-10 09:03:32 +0200 | [diff] [blame] | 242 | smp_mb(); |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 243 | if (waitqueue_active(&pipe->wait)) |
| 244 | wake_up_interruptible_sync(&pipe->wait); |
| 245 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 246 | do_wakeup = 0; |
| 247 | } |
| 248 | |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 249 | pipe->waiting_writers++; |
| 250 | pipe_wait(pipe); |
| 251 | pipe->waiting_writers--; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 252 | } |
| 253 | |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 254 | pipe_unlock(pipe); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 255 | |
Namhyung Kim | 825cdcb | 2011-05-23 19:58:53 +0200 | [diff] [blame] | 256 | if (do_wakeup) |
| 257 | wakeup_pipe_readers(pipe); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 258 | |
Jens Axboe | 00de00b | 2007-06-15 13:14:22 +0200 | [diff] [blame] | 259 | while (page_nr < spd_pages) |
Jens Axboe | bbdfc2f | 2007-11-06 23:29:47 -0800 | [diff] [blame] | 260 | spd->spd_release(spd, page_nr++); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 261 | |
| 262 | return ret; |
| 263 | } |
| 264 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 265 | void spd_release_page(struct splice_pipe_desc *spd, unsigned int i) |
Jens Axboe | bbdfc2f | 2007-11-06 23:29:47 -0800 | [diff] [blame] | 266 | { |
| 267 | page_cache_release(spd->pages[i]); |
| 268 | } |
| 269 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 270 | /* |
| 271 | * Check if we need to grow the arrays holding pages and partial page |
| 272 | * descriptions. |
| 273 | */ |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 274 | int splice_grow_spd(const struct pipe_inode_info *pipe, struct splice_pipe_desc *spd) |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 275 | { |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 276 | unsigned int buffers = ACCESS_ONCE(pipe->buffers); |
| 277 | |
| 278 | spd->nr_pages_max = buffers; |
| 279 | if (buffers <= PIPE_DEF_BUFFERS) |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 280 | return 0; |
| 281 | |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 282 | spd->pages = kmalloc(buffers * sizeof(struct page *), GFP_KERNEL); |
| 283 | spd->partial = kmalloc(buffers * sizeof(struct partial_page), GFP_KERNEL); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 284 | |
| 285 | if (spd->pages && spd->partial) |
| 286 | return 0; |
| 287 | |
| 288 | kfree(spd->pages); |
| 289 | kfree(spd->partial); |
| 290 | return -ENOMEM; |
| 291 | } |
| 292 | |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 293 | void splice_shrink_spd(struct splice_pipe_desc *spd) |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 294 | { |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 295 | if (spd->nr_pages_max <= PIPE_DEF_BUFFERS) |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 296 | return; |
| 297 | |
| 298 | kfree(spd->pages); |
| 299 | kfree(spd->partial); |
| 300 | } |
| 301 | |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 302 | static int |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 303 | __generic_file_splice_read(struct file *in, loff_t *ppos, |
| 304 | struct pipe_inode_info *pipe, size_t len, |
| 305 | unsigned int flags) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 306 | { |
| 307 | struct address_space *mapping = in->f_mapping; |
Fengguang Wu | d898391 | 2007-07-19 01:48:06 -0700 | [diff] [blame] | 308 | unsigned int loff, nr_pages, req_pages; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 309 | struct page *pages[PIPE_DEF_BUFFERS]; |
| 310 | struct partial_page partial[PIPE_DEF_BUFFERS]; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 311 | struct page *page; |
Jens Axboe | 91ad66e | 2006-04-19 15:55:10 +0200 | [diff] [blame] | 312 | pgoff_t index, end_index; |
| 313 | loff_t isize; |
Jens Axboe | eb20796 | 2006-04-27 11:05:22 +0200 | [diff] [blame] | 314 | int error, page_nr; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 315 | struct splice_pipe_desc spd = { |
| 316 | .pages = pages, |
| 317 | .partial = partial, |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 318 | .nr_pages_max = PIPE_DEF_BUFFERS, |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 319 | .flags = flags, |
| 320 | .ops = &page_cache_pipe_buf_ops, |
Jens Axboe | bbdfc2f | 2007-11-06 23:29:47 -0800 | [diff] [blame] | 321 | .spd_release = spd_release_page, |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 322 | }; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 323 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 324 | if (splice_grow_spd(pipe, &spd)) |
| 325 | return -ENOMEM; |
| 326 | |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 327 | index = *ppos >> PAGE_CACHE_SHIFT; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 328 | loff = *ppos & ~PAGE_CACHE_MASK; |
Fengguang Wu | d898391 | 2007-07-19 01:48:06 -0700 | [diff] [blame] | 329 | req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 330 | nr_pages = min(req_pages, spd.nr_pages_max); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 331 | |
| 332 | /* |
Jens Axboe | eb20796 | 2006-04-27 11:05:22 +0200 | [diff] [blame] | 333 | * Lookup the (hopefully) full range of pages we need. |
| 334 | */ |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 335 | spd.nr_pages = find_get_pages_contig(mapping, index, nr_pages, spd.pages); |
Fengguang Wu | 431a482 | 2007-07-19 01:48:05 -0700 | [diff] [blame] | 336 | index += spd.nr_pages; |
Jens Axboe | eb20796 | 2006-04-27 11:05:22 +0200 | [diff] [blame] | 337 | |
| 338 | /* |
| 339 | * If find_get_pages_contig() returned fewer pages than we needed, |
Fengguang Wu | 431a482 | 2007-07-19 01:48:05 -0700 | [diff] [blame] | 340 | * readahead/allocate the rest and fill in the holes. |
Jens Axboe | eb20796 | 2006-04-27 11:05:22 +0200 | [diff] [blame] | 341 | */ |
Fengguang Wu | 431a482 | 2007-07-19 01:48:05 -0700 | [diff] [blame] | 342 | if (spd.nr_pages < nr_pages) |
Rusty Russell | cf914a7 | 2007-07-19 01:48:08 -0700 | [diff] [blame] | 343 | page_cache_sync_readahead(mapping, &in->f_ra, in, |
| 344 | index, req_pages - spd.nr_pages); |
Fengguang Wu | 431a482 | 2007-07-19 01:48:05 -0700 | [diff] [blame] | 345 | |
Jens Axboe | 932cc6d | 2007-06-21 13:10:21 +0200 | [diff] [blame] | 346 | error = 0; |
Jens Axboe | eb20796 | 2006-04-27 11:05:22 +0200 | [diff] [blame] | 347 | while (spd.nr_pages < nr_pages) { |
| 348 | /* |
| 349 | * Page could be there, find_get_pages_contig() breaks on |
| 350 | * the first hole. |
| 351 | */ |
| 352 | page = find_get_page(mapping, index); |
| 353 | if (!page) { |
Jens Axboe | e27dedd | 2006-05-01 19:59:54 +0200 | [diff] [blame] | 354 | /* |
Jens Axboe | eb20796 | 2006-04-27 11:05:22 +0200 | [diff] [blame] | 355 | * page didn't exist, allocate one. |
| 356 | */ |
| 357 | page = page_cache_alloc_cold(mapping); |
| 358 | if (!page) |
| 359 | break; |
| 360 | |
| 361 | error = add_to_page_cache_lru(page, mapping, index, |
Nick Piggin | 0ae0b5d | 2010-05-25 10:25:26 +0200 | [diff] [blame] | 362 | GFP_KERNEL); |
Jens Axboe | eb20796 | 2006-04-27 11:05:22 +0200 | [diff] [blame] | 363 | if (unlikely(error)) { |
| 364 | page_cache_release(page); |
Jens Axboe | a054887 | 2006-05-03 10:58:22 +0200 | [diff] [blame] | 365 | if (error == -EEXIST) |
| 366 | continue; |
Jens Axboe | eb20796 | 2006-04-27 11:05:22 +0200 | [diff] [blame] | 367 | break; |
| 368 | } |
| 369 | /* |
| 370 | * add_to_page_cache() locks the page, unlock it |
| 371 | * to avoid convoluting the logic below even more. |
| 372 | */ |
| 373 | unlock_page(page); |
| 374 | } |
| 375 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 376 | spd.pages[spd.nr_pages++] = page; |
Jens Axboe | eb20796 | 2006-04-27 11:05:22 +0200 | [diff] [blame] | 377 | index++; |
| 378 | } |
| 379 | |
| 380 | /* |
| 381 | * Now loop over the map and see if we need to start IO on any |
| 382 | * pages, fill in the partial map, etc. |
| 383 | */ |
| 384 | index = *ppos >> PAGE_CACHE_SHIFT; |
| 385 | nr_pages = spd.nr_pages; |
| 386 | spd.nr_pages = 0; |
| 387 | for (page_nr = 0; page_nr < nr_pages; page_nr++) { |
Jens Axboe | 82aa5d6 | 2006-04-20 13:05:48 +0200 | [diff] [blame] | 388 | unsigned int this_len; |
| 389 | |
| 390 | if (!len) |
| 391 | break; |
| 392 | |
| 393 | /* |
| 394 | * this_len is the max we'll use from this page |
| 395 | */ |
Andrew Morton | ba5f5d9 | 2006-04-25 15:33:34 +0200 | [diff] [blame] | 396 | this_len = min_t(unsigned long, len, PAGE_CACHE_SIZE - loff); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 397 | page = spd.pages[page_nr]; |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 398 | |
Fengguang Wu | a08a166 | 2007-07-19 01:48:03 -0700 | [diff] [blame] | 399 | if (PageReadahead(page)) |
Rusty Russell | cf914a7 | 2007-07-19 01:48:08 -0700 | [diff] [blame] | 400 | page_cache_async_readahead(mapping, &in->f_ra, in, |
Fengguang Wu | d898391 | 2007-07-19 01:48:06 -0700 | [diff] [blame] | 401 | page, index, req_pages - page_nr); |
Fengguang Wu | a08a166 | 2007-07-19 01:48:03 -0700 | [diff] [blame] | 402 | |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 403 | /* |
| 404 | * If the page isn't uptodate, we may need to start io on it |
| 405 | */ |
| 406 | if (!PageUptodate(page)) { |
Miklos Szeredi | 6965031 | 2010-08-03 12:48:50 +0200 | [diff] [blame] | 407 | lock_page(page); |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 408 | |
| 409 | /* |
Miklos Szeredi | 32502b8 | 2008-07-04 09:35:17 +0200 | [diff] [blame] | 410 | * Page was truncated, or invalidated by the |
| 411 | * filesystem. Redo the find/create, but this time the |
| 412 | * page is kept locked, so there's no chance of another |
| 413 | * race with truncate/invalidate. |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 414 | */ |
| 415 | if (!page->mapping) { |
| 416 | unlock_page(page); |
Miklos Szeredi | 32502b8 | 2008-07-04 09:35:17 +0200 | [diff] [blame] | 417 | page = find_or_create_page(mapping, index, |
| 418 | mapping_gfp_mask(mapping)); |
| 419 | |
| 420 | if (!page) { |
| 421 | error = -ENOMEM; |
| 422 | break; |
| 423 | } |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 424 | page_cache_release(spd.pages[page_nr]); |
| 425 | spd.pages[page_nr] = page; |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 426 | } |
| 427 | /* |
| 428 | * page was already under io and is now done, great |
| 429 | */ |
| 430 | if (PageUptodate(page)) { |
| 431 | unlock_page(page); |
| 432 | goto fill_it; |
| 433 | } |
| 434 | |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 435 | /* |
| 436 | * need to read in the page |
| 437 | */ |
| 438 | error = mapping->a_ops->readpage(in, page); |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 439 | if (unlikely(error)) { |
Jens Axboe | eb20796 | 2006-04-27 11:05:22 +0200 | [diff] [blame] | 440 | /* |
| 441 | * We really should re-lookup the page here, |
| 442 | * but it complicates things a lot. Instead |
| 443 | * lets just do what we already stored, and |
| 444 | * we'll get it the next time we are called. |
| 445 | */ |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 446 | if (error == AOP_TRUNCATED_PAGE) |
Jens Axboe | eb20796 | 2006-04-27 11:05:22 +0200 | [diff] [blame] | 447 | error = 0; |
| 448 | |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 449 | break; |
| 450 | } |
Jens Axboe | 620a324 | 2007-06-07 09:39:42 +0200 | [diff] [blame] | 451 | } |
| 452 | fill_it: |
| 453 | /* |
| 454 | * i_size must be checked after PageUptodate. |
| 455 | */ |
| 456 | isize = i_size_read(mapping->host); |
| 457 | end_index = (isize - 1) >> PAGE_CACHE_SHIFT; |
| 458 | if (unlikely(!isize || index > end_index)) |
| 459 | break; |
| 460 | |
| 461 | /* |
| 462 | * if this is the last page, see if we need to shrink |
| 463 | * the length and stop |
| 464 | */ |
| 465 | if (end_index == index) { |
| 466 | unsigned int plen; |
Jens Axboe | 91ad66e | 2006-04-19 15:55:10 +0200 | [diff] [blame] | 467 | |
| 468 | /* |
Jens Axboe | 620a324 | 2007-06-07 09:39:42 +0200 | [diff] [blame] | 469 | * max good bytes in this page |
Jens Axboe | 91ad66e | 2006-04-19 15:55:10 +0200 | [diff] [blame] | 470 | */ |
Jens Axboe | 620a324 | 2007-06-07 09:39:42 +0200 | [diff] [blame] | 471 | plen = ((isize - 1) & ~PAGE_CACHE_MASK) + 1; |
| 472 | if (plen <= loff) |
Jens Axboe | 91ad66e | 2006-04-19 15:55:10 +0200 | [diff] [blame] | 473 | break; |
Jens Axboe | 91ad66e | 2006-04-19 15:55:10 +0200 | [diff] [blame] | 474 | |
| 475 | /* |
Jens Axboe | 620a324 | 2007-06-07 09:39:42 +0200 | [diff] [blame] | 476 | * force quit after adding this page |
Jens Axboe | 91ad66e | 2006-04-19 15:55:10 +0200 | [diff] [blame] | 477 | */ |
Jens Axboe | 620a324 | 2007-06-07 09:39:42 +0200 | [diff] [blame] | 478 | this_len = min(this_len, plen - loff); |
| 479 | len = this_len; |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 480 | } |
Jens Axboe | 620a324 | 2007-06-07 09:39:42 +0200 | [diff] [blame] | 481 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 482 | spd.partial[page_nr].offset = loff; |
| 483 | spd.partial[page_nr].len = this_len; |
Jens Axboe | 82aa5d6 | 2006-04-20 13:05:48 +0200 | [diff] [blame] | 484 | len -= this_len; |
Jens Axboe | 91ad66e | 2006-04-19 15:55:10 +0200 | [diff] [blame] | 485 | loff = 0; |
Jens Axboe | eb20796 | 2006-04-27 11:05:22 +0200 | [diff] [blame] | 486 | spd.nr_pages++; |
| 487 | index++; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 488 | } |
| 489 | |
Jens Axboe | eb20796 | 2006-04-27 11:05:22 +0200 | [diff] [blame] | 490 | /* |
Hugh Dickins | 475ecad | 2007-06-07 09:36:00 +0200 | [diff] [blame] | 491 | * Release any pages at the end, if we quit early. 'page_nr' is how far |
Jens Axboe | eb20796 | 2006-04-27 11:05:22 +0200 | [diff] [blame] | 492 | * we got, 'nr_pages' is how many pages are in the map. |
| 493 | */ |
| 494 | while (page_nr < nr_pages) |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 495 | page_cache_release(spd.pages[page_nr++]); |
Fengguang Wu | f4e6b49 | 2007-10-16 01:24:33 -0700 | [diff] [blame] | 496 | in->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT; |
Jens Axboe | eb20796 | 2006-04-27 11:05:22 +0200 | [diff] [blame] | 497 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 498 | if (spd.nr_pages) |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 499 | error = splice_to_pipe(pipe, &spd); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 500 | |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 501 | splice_shrink_spd(&spd); |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 502 | return error; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 503 | } |
| 504 | |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 505 | /** |
| 506 | * generic_file_splice_read - splice data from file to a pipe |
| 507 | * @in: file to splice from |
Jens Axboe | 932cc6d | 2007-06-21 13:10:21 +0200 | [diff] [blame] | 508 | * @ppos: position in @in |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 509 | * @pipe: pipe to splice to |
| 510 | * @len: number of bytes to splice |
| 511 | * @flags: splice modifier flags |
| 512 | * |
Jens Axboe | 932cc6d | 2007-06-21 13:10:21 +0200 | [diff] [blame] | 513 | * Description: |
| 514 | * Will read pages from given file and fill them into a pipe. Can be |
| 515 | * used as long as the address_space operations for the source implements |
| 516 | * a readpage() hook. |
| 517 | * |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 518 | */ |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 519 | ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, |
| 520 | struct pipe_inode_info *pipe, size_t len, |
| 521 | unsigned int flags) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 522 | { |
Jens Axboe | d366d398 | 2007-06-01 14:54:11 +0200 | [diff] [blame] | 523 | loff_t isize, left; |
Jens Axboe | 8191ecd | 2008-04-10 08:24:25 +0200 | [diff] [blame] | 524 | int ret; |
Jens Axboe | d366d398 | 2007-06-01 14:54:11 +0200 | [diff] [blame] | 525 | |
| 526 | isize = i_size_read(in->f_mapping->host); |
| 527 | if (unlikely(*ppos >= isize)) |
| 528 | return 0; |
| 529 | |
| 530 | left = isize - *ppos; |
| 531 | if (unlikely(left < len)) |
| 532 | len = left; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 533 | |
Jens Axboe | 8191ecd | 2008-04-10 08:24:25 +0200 | [diff] [blame] | 534 | ret = __generic_file_splice_read(in, ppos, pipe, len, flags); |
Miklos Szeredi | 723590e | 2009-08-15 08:43:22 +0200 | [diff] [blame] | 535 | if (ret > 0) { |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 536 | *ppos += ret; |
Miklos Szeredi | 723590e | 2009-08-15 08:43:22 +0200 | [diff] [blame] | 537 | file_accessed(in); |
| 538 | } |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 539 | |
| 540 | return ret; |
| 541 | } |
Jens Axboe | 059a8f3 | 2006-04-02 23:06:05 +0200 | [diff] [blame] | 542 | EXPORT_SYMBOL(generic_file_splice_read); |
| 543 | |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 544 | static const struct pipe_buf_operations default_pipe_buf_ops = { |
| 545 | .can_merge = 0, |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 546 | .confirm = generic_pipe_buf_confirm, |
| 547 | .release = generic_pipe_buf_release, |
| 548 | .steal = generic_pipe_buf_steal, |
| 549 | .get = generic_pipe_buf_get, |
| 550 | }; |
| 551 | |
Miklos Szeredi | 28a625c | 2014-01-22 19:36:57 +0100 | [diff] [blame] | 552 | static int generic_pipe_buf_nosteal(struct pipe_inode_info *pipe, |
| 553 | struct pipe_buffer *buf) |
| 554 | { |
| 555 | return 1; |
| 556 | } |
| 557 | |
| 558 | /* Pipe buffer operations for a socket and similar. */ |
| 559 | const struct pipe_buf_operations nosteal_pipe_buf_ops = { |
| 560 | .can_merge = 0, |
Miklos Szeredi | 28a625c | 2014-01-22 19:36:57 +0100 | [diff] [blame] | 561 | .confirm = generic_pipe_buf_confirm, |
| 562 | .release = generic_pipe_buf_release, |
| 563 | .steal = generic_pipe_buf_nosteal, |
| 564 | .get = generic_pipe_buf_get, |
| 565 | }; |
| 566 | EXPORT_SYMBOL(nosteal_pipe_buf_ops); |
| 567 | |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 568 | static ssize_t kernel_readv(struct file *file, const struct iovec *vec, |
| 569 | unsigned long vlen, loff_t offset) |
| 570 | { |
| 571 | mm_segment_t old_fs; |
| 572 | loff_t pos = offset; |
| 573 | ssize_t res; |
| 574 | |
| 575 | old_fs = get_fs(); |
| 576 | set_fs(get_ds()); |
| 577 | /* The cast to a user pointer is valid due to the set_fs() */ |
| 578 | res = vfs_readv(file, (const struct iovec __user *)vec, vlen, &pos); |
| 579 | set_fs(old_fs); |
| 580 | |
| 581 | return res; |
| 582 | } |
| 583 | |
Al Viro | 7bb307e | 2013-02-23 14:51:48 -0500 | [diff] [blame] | 584 | ssize_t kernel_write(struct file *file, const char *buf, size_t count, |
Miklos Szeredi | b2858d7 | 2009-05-19 11:37:46 +0200 | [diff] [blame] | 585 | loff_t pos) |
Miklos Szeredi | 0b0a47f | 2009-05-07 15:37:37 +0200 | [diff] [blame] | 586 | { |
| 587 | mm_segment_t old_fs; |
| 588 | ssize_t res; |
| 589 | |
| 590 | old_fs = get_fs(); |
| 591 | set_fs(get_ds()); |
| 592 | /* The cast to a user pointer is valid due to the set_fs() */ |
Al Viro | 7bb307e | 2013-02-23 14:51:48 -0500 | [diff] [blame] | 593 | res = vfs_write(file, (__force const char __user *)buf, count, &pos); |
Miklos Szeredi | 0b0a47f | 2009-05-07 15:37:37 +0200 | [diff] [blame] | 594 | set_fs(old_fs); |
| 595 | |
| 596 | return res; |
| 597 | } |
Al Viro | 7bb307e | 2013-02-23 14:51:48 -0500 | [diff] [blame] | 598 | EXPORT_SYMBOL(kernel_write); |
Miklos Szeredi | 0b0a47f | 2009-05-07 15:37:37 +0200 | [diff] [blame] | 599 | |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 600 | ssize_t default_file_splice_read(struct file *in, loff_t *ppos, |
| 601 | struct pipe_inode_info *pipe, size_t len, |
| 602 | unsigned int flags) |
| 603 | { |
| 604 | unsigned int nr_pages; |
| 605 | unsigned int nr_freed; |
| 606 | size_t offset; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 607 | struct page *pages[PIPE_DEF_BUFFERS]; |
| 608 | struct partial_page partial[PIPE_DEF_BUFFERS]; |
| 609 | struct iovec *vec, __vec[PIPE_DEF_BUFFERS]; |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 610 | ssize_t res; |
| 611 | size_t this_len; |
| 612 | int error; |
| 613 | int i; |
| 614 | struct splice_pipe_desc spd = { |
| 615 | .pages = pages, |
| 616 | .partial = partial, |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 617 | .nr_pages_max = PIPE_DEF_BUFFERS, |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 618 | .flags = flags, |
| 619 | .ops = &default_pipe_buf_ops, |
| 620 | .spd_release = spd_release_page, |
| 621 | }; |
| 622 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 623 | if (splice_grow_spd(pipe, &spd)) |
| 624 | return -ENOMEM; |
| 625 | |
| 626 | res = -ENOMEM; |
| 627 | vec = __vec; |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 628 | if (spd.nr_pages_max > PIPE_DEF_BUFFERS) { |
| 629 | vec = kmalloc(spd.nr_pages_max * sizeof(struct iovec), GFP_KERNEL); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 630 | if (!vec) |
| 631 | goto shrink_ret; |
| 632 | } |
| 633 | |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 634 | offset = *ppos & ~PAGE_CACHE_MASK; |
| 635 | nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
| 636 | |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 637 | for (i = 0; i < nr_pages && i < spd.nr_pages_max && len; i++) { |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 638 | struct page *page; |
| 639 | |
Jens Axboe | 4f23122 | 2009-05-13 08:35:35 +0200 | [diff] [blame] | 640 | page = alloc_page(GFP_USER); |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 641 | error = -ENOMEM; |
| 642 | if (!page) |
| 643 | goto err; |
| 644 | |
| 645 | this_len = min_t(size_t, len, PAGE_CACHE_SIZE - offset); |
Jens Axboe | 4f23122 | 2009-05-13 08:35:35 +0200 | [diff] [blame] | 646 | vec[i].iov_base = (void __user *) page_address(page); |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 647 | vec[i].iov_len = this_len; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 648 | spd.pages[i] = page; |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 649 | spd.nr_pages++; |
| 650 | len -= this_len; |
| 651 | offset = 0; |
| 652 | } |
| 653 | |
| 654 | res = kernel_readv(in, vec, spd.nr_pages, *ppos); |
Andrew Morton | 77f6bf5 | 2009-05-14 09:49:44 +0200 | [diff] [blame] | 655 | if (res < 0) { |
| 656 | error = res; |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 657 | goto err; |
Andrew Morton | 77f6bf5 | 2009-05-14 09:49:44 +0200 | [diff] [blame] | 658 | } |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 659 | |
| 660 | error = 0; |
| 661 | if (!res) |
| 662 | goto err; |
| 663 | |
| 664 | nr_freed = 0; |
| 665 | for (i = 0; i < spd.nr_pages; i++) { |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 666 | this_len = min_t(size_t, vec[i].iov_len, res); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 667 | spd.partial[i].offset = 0; |
| 668 | spd.partial[i].len = this_len; |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 669 | if (!this_len) { |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 670 | __free_page(spd.pages[i]); |
| 671 | spd.pages[i] = NULL; |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 672 | nr_freed++; |
| 673 | } |
| 674 | res -= this_len; |
| 675 | } |
| 676 | spd.nr_pages -= nr_freed; |
| 677 | |
| 678 | res = splice_to_pipe(pipe, &spd); |
| 679 | if (res > 0) |
| 680 | *ppos += res; |
| 681 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 682 | shrink_ret: |
| 683 | if (vec != __vec) |
| 684 | kfree(vec); |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 685 | splice_shrink_spd(&spd); |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 686 | return res; |
| 687 | |
| 688 | err: |
Jens Axboe | 4f23122 | 2009-05-13 08:35:35 +0200 | [diff] [blame] | 689 | for (i = 0; i < spd.nr_pages; i++) |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 690 | __free_page(spd.pages[i]); |
Jens Axboe | 4f23122 | 2009-05-13 08:35:35 +0200 | [diff] [blame] | 691 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 692 | res = error; |
| 693 | goto shrink_ret; |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 694 | } |
| 695 | EXPORT_SYMBOL(default_file_splice_read); |
| 696 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 697 | /* |
Jens Axboe | 4f6f0bd | 2006-04-02 23:04:46 +0200 | [diff] [blame] | 698 | * Send 'sd->len' bytes to socket from 'sd->file' at position 'sd->pos' |
Jens Axboe | 016b661 | 2006-04-25 15:42:00 +0200 | [diff] [blame] | 699 | * using sendpage(). Return the number of bytes sent. |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 700 | */ |
Jens Axboe | 76ad4d1 | 2006-05-03 10:41:33 +0200 | [diff] [blame] | 701 | static int pipe_to_sendpage(struct pipe_inode_info *pipe, |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 702 | struct pipe_buffer *buf, struct splice_desc *sd) |
| 703 | { |
Jens Axboe | 6a14b90 | 2007-06-14 13:08:55 +0200 | [diff] [blame] | 704 | struct file *file = sd->u.file; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 705 | loff_t pos = sd->pos; |
Michał Mirosław | a8adbe3 | 2010-12-17 08:56:44 +0100 | [diff] [blame] | 706 | int more; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 707 | |
Al Viro | 72c2d53 | 2013-09-22 16:27:52 -0400 | [diff] [blame] | 708 | if (!likely(file->f_op->sendpage)) |
Michał Mirosław | a8adbe3 | 2010-12-17 08:56:44 +0100 | [diff] [blame] | 709 | return -EINVAL; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 710 | |
Eric Dumazet | 35f9c09 | 2012-04-05 03:05:35 +0000 | [diff] [blame] | 711 | more = (sd->flags & SPLICE_F_MORE) ? MSG_MORE : 0; |
Eric Dumazet | ae62ca7 | 2013-01-06 18:21:49 +0000 | [diff] [blame] | 712 | |
| 713 | if (sd->len < sd->total_len && pipe->nrbufs > 1) |
Eric Dumazet | 35f9c09 | 2012-04-05 03:05:35 +0000 | [diff] [blame] | 714 | more |= MSG_SENDPAGE_NOTLAST; |
Eric Dumazet | ae62ca7 | 2013-01-06 18:21:49 +0000 | [diff] [blame] | 715 | |
Michał Mirosław | a8adbe3 | 2010-12-17 08:56:44 +0100 | [diff] [blame] | 716 | return file->f_op->sendpage(file, buf->page, buf->offset, |
| 717 | sd->len, &pos, more); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 718 | } |
| 719 | |
| 720 | /* |
| 721 | * This is a little more tricky than the file -> pipe splicing. There are |
| 722 | * basically three cases: |
| 723 | * |
| 724 | * - Destination page already exists in the address space and there |
| 725 | * are users of it. For that case we have no other option that |
| 726 | * copying the data. Tough luck. |
| 727 | * - Destination page already exists in the address space, but there |
| 728 | * are no users of it. Make sure it's uptodate, then drop it. Fall |
| 729 | * through to last case. |
| 730 | * - Destination page does not exist, we can add the pipe page to |
| 731 | * the page cache and avoid the copy. |
| 732 | * |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 733 | * If asked to move pages to the output file (SPLICE_F_MOVE is set in |
| 734 | * sd->flags), we attempt to migrate pages from the pipe to the output |
| 735 | * file address space page cache. This is possible if no one else has |
| 736 | * the pipe page referenced outside of the pipe and page cache. If |
| 737 | * SPLICE_F_MOVE isn't set, or we cannot move the page, we simply create |
| 738 | * a new page in the output file page cache and fill/dirty that. |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 739 | */ |
Miklos Szeredi | 328eaab | 2009-04-14 19:48:39 +0200 | [diff] [blame] | 740 | int pipe_to_file(struct pipe_inode_info *pipe, struct pipe_buffer *buf, |
| 741 | struct splice_desc *sd) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 742 | { |
Jens Axboe | 6a14b90 | 2007-06-14 13:08:55 +0200 | [diff] [blame] | 743 | struct file *file = sd->u.file; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 744 | struct address_space *mapping = file->f_mapping; |
Jens Axboe | 016b661 | 2006-04-25 15:42:00 +0200 | [diff] [blame] | 745 | unsigned int offset, this_len; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 746 | struct page *page; |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 747 | void *fsdata; |
Jens Axboe | 3e7ee3e | 2006-04-02 23:11:04 +0200 | [diff] [blame] | 748 | int ret; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 749 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 750 | offset = sd->pos & ~PAGE_CACHE_MASK; |
| 751 | |
Jens Axboe | 016b661 | 2006-04-25 15:42:00 +0200 | [diff] [blame] | 752 | this_len = sd->len; |
| 753 | if (this_len + offset > PAGE_CACHE_SIZE) |
| 754 | this_len = PAGE_CACHE_SIZE - offset; |
| 755 | |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 756 | ret = pagecache_write_begin(file, mapping, sd->pos, this_len, |
| 757 | AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata); |
| 758 | if (unlikely(ret)) |
| 759 | goto out; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 760 | |
Jens Axboe | 0568b40 | 2006-05-01 19:50:48 +0200 | [diff] [blame] | 761 | if (buf->page != page) { |
Al Viro | fbb3275 | 2014-02-02 21:09:54 -0500 | [diff] [blame] | 762 | char *src = kmap_atomic(buf->page); |
Cong Wang | e8e3c3d | 2011-11-25 23:14:27 +0800 | [diff] [blame] | 763 | char *dst = kmap_atomic(page); |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 764 | |
Jens Axboe | 016b661 | 2006-04-25 15:42:00 +0200 | [diff] [blame] | 765 | memcpy(dst + offset, src + buf->offset, this_len); |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 766 | flush_dcache_page(page); |
Cong Wang | e8e3c3d | 2011-11-25 23:14:27 +0800 | [diff] [blame] | 767 | kunmap_atomic(dst); |
Al Viro | fbb3275 | 2014-02-02 21:09:54 -0500 | [diff] [blame] | 768 | kunmap_atomic(src); |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 769 | } |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 770 | ret = pagecache_write_end(file, mapping, sd->pos, this_len, this_len, |
| 771 | page, fsdata); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 772 | out: |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 773 | return ret; |
| 774 | } |
Miklos Szeredi | 328eaab | 2009-04-14 19:48:39 +0200 | [diff] [blame] | 775 | EXPORT_SYMBOL(pipe_to_file); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 776 | |
Miklos Szeredi | b3c2d2d | 2009-04-14 19:48:36 +0200 | [diff] [blame] | 777 | static void wakeup_pipe_writers(struct pipe_inode_info *pipe) |
| 778 | { |
| 779 | smp_mb(); |
| 780 | if (waitqueue_active(&pipe->wait)) |
| 781 | wake_up_interruptible(&pipe->wait); |
| 782 | kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); |
| 783 | } |
| 784 | |
| 785 | /** |
| 786 | * splice_from_pipe_feed - feed available data from a pipe to a file |
| 787 | * @pipe: pipe to splice from |
| 788 | * @sd: information to @actor |
| 789 | * @actor: handler that splices the data |
| 790 | * |
| 791 | * Description: |
Miklos Szeredi | b3c2d2d | 2009-04-14 19:48:36 +0200 | [diff] [blame] | 792 | * This function loops over the pipe and calls @actor to do the |
| 793 | * actual moving of a single struct pipe_buffer to the desired |
| 794 | * destination. It returns when there's no more buffers left in |
| 795 | * the pipe or if the requested number of bytes (@sd->total_len) |
| 796 | * have been copied. It returns a positive number (one) if the |
| 797 | * pipe needs to be filled with more data, zero if the required |
| 798 | * number of bytes have been copied and -errno on error. |
| 799 | * |
| 800 | * This, together with splice_from_pipe_{begin,end,next}, may be |
| 801 | * used to implement the functionality of __splice_from_pipe() when |
| 802 | * locking is required around copying the pipe buffers to the |
| 803 | * destination. |
| 804 | */ |
| 805 | int splice_from_pipe_feed(struct pipe_inode_info *pipe, struct splice_desc *sd, |
| 806 | splice_actor *actor) |
| 807 | { |
| 808 | int ret; |
| 809 | |
| 810 | while (pipe->nrbufs) { |
| 811 | struct pipe_buffer *buf = pipe->bufs + pipe->curbuf; |
| 812 | const struct pipe_buf_operations *ops = buf->ops; |
| 813 | |
| 814 | sd->len = buf->len; |
| 815 | if (sd->len > sd->total_len) |
| 816 | sd->len = sd->total_len; |
| 817 | |
Michał Mirosław | a8adbe3 | 2010-12-17 08:56:44 +0100 | [diff] [blame] | 818 | ret = buf->ops->confirm(pipe, buf); |
| 819 | if (unlikely(ret)) { |
Miklos Szeredi | b3c2d2d | 2009-04-14 19:48:36 +0200 | [diff] [blame] | 820 | if (ret == -ENODATA) |
| 821 | ret = 0; |
| 822 | return ret; |
| 823 | } |
Michał Mirosław | a8adbe3 | 2010-12-17 08:56:44 +0100 | [diff] [blame] | 824 | |
| 825 | ret = actor(pipe, buf, sd); |
| 826 | if (ret <= 0) |
| 827 | return ret; |
| 828 | |
Miklos Szeredi | b3c2d2d | 2009-04-14 19:48:36 +0200 | [diff] [blame] | 829 | buf->offset += ret; |
| 830 | buf->len -= ret; |
| 831 | |
| 832 | sd->num_spliced += ret; |
| 833 | sd->len -= ret; |
| 834 | sd->pos += ret; |
| 835 | sd->total_len -= ret; |
| 836 | |
| 837 | if (!buf->len) { |
| 838 | buf->ops = NULL; |
| 839 | ops->release(pipe, buf); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 840 | pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1); |
Miklos Szeredi | b3c2d2d | 2009-04-14 19:48:36 +0200 | [diff] [blame] | 841 | pipe->nrbufs--; |
Al Viro | 6447a3c | 2013-03-21 11:01:38 -0400 | [diff] [blame] | 842 | if (pipe->files) |
Miklos Szeredi | b3c2d2d | 2009-04-14 19:48:36 +0200 | [diff] [blame] | 843 | sd->need_wakeup = true; |
| 844 | } |
| 845 | |
| 846 | if (!sd->total_len) |
| 847 | return 0; |
| 848 | } |
| 849 | |
| 850 | return 1; |
| 851 | } |
| 852 | EXPORT_SYMBOL(splice_from_pipe_feed); |
| 853 | |
| 854 | /** |
| 855 | * splice_from_pipe_next - wait for some data to splice from |
| 856 | * @pipe: pipe to splice from |
| 857 | * @sd: information about the splice operation |
| 858 | * |
| 859 | * Description: |
| 860 | * This function will wait for some data and return a positive |
| 861 | * value (one) if pipe buffers are available. It will return zero |
| 862 | * or -errno if no more data needs to be spliced. |
| 863 | */ |
| 864 | int splice_from_pipe_next(struct pipe_inode_info *pipe, struct splice_desc *sd) |
| 865 | { |
| 866 | while (!pipe->nrbufs) { |
| 867 | if (!pipe->writers) |
| 868 | return 0; |
| 869 | |
| 870 | if (!pipe->waiting_writers && sd->num_spliced) |
| 871 | return 0; |
| 872 | |
| 873 | if (sd->flags & SPLICE_F_NONBLOCK) |
| 874 | return -EAGAIN; |
| 875 | |
| 876 | if (signal_pending(current)) |
| 877 | return -ERESTARTSYS; |
| 878 | |
| 879 | if (sd->need_wakeup) { |
| 880 | wakeup_pipe_writers(pipe); |
| 881 | sd->need_wakeup = false; |
| 882 | } |
| 883 | |
| 884 | pipe_wait(pipe); |
| 885 | } |
| 886 | |
| 887 | return 1; |
| 888 | } |
| 889 | EXPORT_SYMBOL(splice_from_pipe_next); |
| 890 | |
| 891 | /** |
| 892 | * splice_from_pipe_begin - start splicing from pipe |
Randy Dunlap | b80901b | 2009-04-16 19:09:55 -0700 | [diff] [blame] | 893 | * @sd: information about the splice operation |
Miklos Szeredi | b3c2d2d | 2009-04-14 19:48:36 +0200 | [diff] [blame] | 894 | * |
| 895 | * Description: |
| 896 | * This function should be called before a loop containing |
| 897 | * splice_from_pipe_next() and splice_from_pipe_feed() to |
| 898 | * initialize the necessary fields of @sd. |
| 899 | */ |
| 900 | void splice_from_pipe_begin(struct splice_desc *sd) |
| 901 | { |
| 902 | sd->num_spliced = 0; |
| 903 | sd->need_wakeup = false; |
| 904 | } |
| 905 | EXPORT_SYMBOL(splice_from_pipe_begin); |
| 906 | |
| 907 | /** |
| 908 | * splice_from_pipe_end - finish splicing from pipe |
| 909 | * @pipe: pipe to splice from |
| 910 | * @sd: information about the splice operation |
| 911 | * |
| 912 | * Description: |
| 913 | * This function will wake up pipe writers if necessary. It should |
| 914 | * be called after a loop containing splice_from_pipe_next() and |
| 915 | * splice_from_pipe_feed(). |
| 916 | */ |
| 917 | void splice_from_pipe_end(struct pipe_inode_info *pipe, struct splice_desc *sd) |
| 918 | { |
| 919 | if (sd->need_wakeup) |
| 920 | wakeup_pipe_writers(pipe); |
| 921 | } |
| 922 | EXPORT_SYMBOL(splice_from_pipe_end); |
| 923 | |
Jens Axboe | 932cc6d | 2007-06-21 13:10:21 +0200 | [diff] [blame] | 924 | /** |
| 925 | * __splice_from_pipe - splice data from a pipe to given actor |
| 926 | * @pipe: pipe to splice from |
| 927 | * @sd: information to @actor |
| 928 | * @actor: handler that splices the data |
| 929 | * |
| 930 | * Description: |
| 931 | * This function does little more than loop over the pipe and call |
| 932 | * @actor to do the actual moving of a single struct pipe_buffer to |
| 933 | * the desired destination. See pipe_to_file, pipe_to_sendpage, or |
| 934 | * pipe_to_user. |
| 935 | * |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 936 | */ |
Jens Axboe | c66ab6f | 2007-06-12 21:17:17 +0200 | [diff] [blame] | 937 | ssize_t __splice_from_pipe(struct pipe_inode_info *pipe, struct splice_desc *sd, |
| 938 | splice_actor *actor) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 939 | { |
Miklos Szeredi | b3c2d2d | 2009-04-14 19:48:36 +0200 | [diff] [blame] | 940 | int ret; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 941 | |
Miklos Szeredi | b3c2d2d | 2009-04-14 19:48:36 +0200 | [diff] [blame] | 942 | splice_from_pipe_begin(sd); |
| 943 | do { |
| 944 | ret = splice_from_pipe_next(pipe, sd); |
| 945 | if (ret > 0) |
| 946 | ret = splice_from_pipe_feed(pipe, sd, actor); |
| 947 | } while (ret > 0); |
| 948 | splice_from_pipe_end(pipe, sd); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 949 | |
Miklos Szeredi | b3c2d2d | 2009-04-14 19:48:36 +0200 | [diff] [blame] | 950 | return sd->num_spliced ? sd->num_spliced : ret; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 951 | } |
Mark Fasheh | 40bee44e | 2007-03-21 13:11:02 +0100 | [diff] [blame] | 952 | EXPORT_SYMBOL(__splice_from_pipe); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 953 | |
Jens Axboe | 932cc6d | 2007-06-21 13:10:21 +0200 | [diff] [blame] | 954 | /** |
| 955 | * splice_from_pipe - splice data from a pipe to a file |
| 956 | * @pipe: pipe to splice from |
| 957 | * @out: file to splice to |
| 958 | * @ppos: position in @out |
| 959 | * @len: how many bytes to splice |
| 960 | * @flags: splice modifier flags |
| 961 | * @actor: handler that splices the data |
| 962 | * |
| 963 | * Description: |
Miklos Szeredi | 2933970 | 2009-04-14 19:48:37 +0200 | [diff] [blame] | 964 | * See __splice_from_pipe. This function locks the pipe inode, |
Jens Axboe | 932cc6d | 2007-06-21 13:10:21 +0200 | [diff] [blame] | 965 | * otherwise it's identical to __splice_from_pipe(). |
| 966 | * |
| 967 | */ |
Mark Fasheh | 6da6180 | 2006-10-17 18:43:07 +0200 | [diff] [blame] | 968 | ssize_t splice_from_pipe(struct pipe_inode_info *pipe, struct file *out, |
| 969 | loff_t *ppos, size_t len, unsigned int flags, |
| 970 | splice_actor *actor) |
| 971 | { |
| 972 | ssize_t ret; |
Jens Axboe | c66ab6f | 2007-06-12 21:17:17 +0200 | [diff] [blame] | 973 | struct splice_desc sd = { |
| 974 | .total_len = len, |
| 975 | .flags = flags, |
| 976 | .pos = *ppos, |
Jens Axboe | 6a14b90 | 2007-06-14 13:08:55 +0200 | [diff] [blame] | 977 | .u.file = out, |
Jens Axboe | c66ab6f | 2007-06-12 21:17:17 +0200 | [diff] [blame] | 978 | }; |
Mark Fasheh | 6da6180 | 2006-10-17 18:43:07 +0200 | [diff] [blame] | 979 | |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 980 | pipe_lock(pipe); |
Jens Axboe | c66ab6f | 2007-06-12 21:17:17 +0200 | [diff] [blame] | 981 | ret = __splice_from_pipe(pipe, &sd, actor); |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 982 | pipe_unlock(pipe); |
Mark Fasheh | 6da6180 | 2006-10-17 18:43:07 +0200 | [diff] [blame] | 983 | |
| 984 | return ret; |
| 985 | } |
| 986 | |
| 987 | /** |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 988 | * generic_file_splice_write - splice data from a pipe to a file |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 989 | * @pipe: pipe info |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 990 | * @out: file to write to |
Jens Axboe | 932cc6d | 2007-06-21 13:10:21 +0200 | [diff] [blame] | 991 | * @ppos: position in @out |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 992 | * @len: number of bytes to splice |
| 993 | * @flags: splice modifier flags |
| 994 | * |
Jens Axboe | 932cc6d | 2007-06-21 13:10:21 +0200 | [diff] [blame] | 995 | * Description: |
| 996 | * Will either move or copy pages (determined by @flags options) from |
| 997 | * the given pipe inode to the given file. |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 998 | * |
| 999 | */ |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 1000 | ssize_t |
| 1001 | generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out, |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 1002 | loff_t *ppos, size_t len, unsigned int flags) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1003 | { |
Jens Axboe | 4f6f0bd | 2006-04-02 23:04:46 +0200 | [diff] [blame] | 1004 | struct address_space *mapping = out->f_mapping; |
Jens Axboe | 8c34e2d | 2006-10-17 19:43:22 +0200 | [diff] [blame] | 1005 | struct inode *inode = mapping->host; |
Miklos Szeredi | 7f3d4ee | 2008-05-07 09:22:39 +0200 | [diff] [blame] | 1006 | struct splice_desc sd = { |
| 1007 | .total_len = len, |
| 1008 | .flags = flags, |
| 1009 | .pos = *ppos, |
| 1010 | .u.file = out, |
| 1011 | }; |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 1012 | ssize_t ret; |
Jens Axboe | 8c34e2d | 2006-10-17 19:43:22 +0200 | [diff] [blame] | 1013 | |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 1014 | pipe_lock(pipe); |
Miklos Szeredi | eb443e5 | 2009-04-14 19:48:38 +0200 | [diff] [blame] | 1015 | |
| 1016 | splice_from_pipe_begin(&sd); |
| 1017 | do { |
| 1018 | ret = splice_from_pipe_next(pipe, &sd); |
| 1019 | if (ret <= 0) |
| 1020 | break; |
| 1021 | |
| 1022 | mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD); |
| 1023 | ret = file_remove_suid(out); |
Miklos Szeredi | 723590e | 2009-08-15 08:43:22 +0200 | [diff] [blame] | 1024 | if (!ret) { |
Josef Bacik | c3b2da3 | 2012-03-26 09:59:21 -0400 | [diff] [blame] | 1025 | ret = file_update_time(out); |
| 1026 | if (!ret) |
| 1027 | ret = splice_from_pipe_feed(pipe, &sd, |
| 1028 | pipe_to_file); |
Miklos Szeredi | 723590e | 2009-08-15 08:43:22 +0200 | [diff] [blame] | 1029 | } |
Miklos Szeredi | eb443e5 | 2009-04-14 19:48:38 +0200 | [diff] [blame] | 1030 | mutex_unlock(&inode->i_mutex); |
| 1031 | } while (ret > 0); |
| 1032 | splice_from_pipe_end(pipe, &sd); |
| 1033 | |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 1034 | pipe_unlock(pipe); |
Miklos Szeredi | eb443e5 | 2009-04-14 19:48:38 +0200 | [diff] [blame] | 1035 | |
| 1036 | if (sd.num_spliced) |
| 1037 | ret = sd.num_spliced; |
| 1038 | |
Jens Axboe | a4514eb | 2006-04-19 15:57:05 +0200 | [diff] [blame] | 1039 | if (ret > 0) { |
Jan Kara | 148f948 | 2009-08-17 19:52:36 +0200 | [diff] [blame] | 1040 | int err; |
Jens Axboe | 17ee4f4 | 2007-06-15 13:10:37 +0200 | [diff] [blame] | 1041 | |
Jan Kara | 148f948 | 2009-08-17 19:52:36 +0200 | [diff] [blame] | 1042 | err = generic_write_sync(out, *ppos, ret); |
| 1043 | if (err) |
| 1044 | ret = err; |
| 1045 | else |
| 1046 | *ppos += ret; |
Namjae Jeon | d0e1d66 | 2012-12-11 16:00:21 -0800 | [diff] [blame] | 1047 | balance_dirty_pages_ratelimited(mapping); |
Jens Axboe | 4f6f0bd | 2006-04-02 23:04:46 +0200 | [diff] [blame] | 1048 | } |
| 1049 | |
| 1050 | return ret; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1051 | } |
| 1052 | |
Jens Axboe | 059a8f3 | 2006-04-02 23:06:05 +0200 | [diff] [blame] | 1053 | EXPORT_SYMBOL(generic_file_splice_write); |
| 1054 | |
Miklos Szeredi | b2858d7 | 2009-05-19 11:37:46 +0200 | [diff] [blame] | 1055 | static int write_pipe_buf(struct pipe_inode_info *pipe, struct pipe_buffer *buf, |
| 1056 | struct splice_desc *sd) |
Miklos Szeredi | 0b0a47f | 2009-05-07 15:37:37 +0200 | [diff] [blame] | 1057 | { |
Miklos Szeredi | b2858d7 | 2009-05-19 11:37:46 +0200 | [diff] [blame] | 1058 | int ret; |
| 1059 | void *data; |
Al Viro | 06ae43f | 2013-03-20 13:19:30 -0400 | [diff] [blame] | 1060 | loff_t tmp = sd->pos; |
Miklos Szeredi | b2858d7 | 2009-05-19 11:37:46 +0200 | [diff] [blame] | 1061 | |
Al Viro | fbb3275 | 2014-02-02 21:09:54 -0500 | [diff] [blame] | 1062 | data = kmap(buf->page); |
Al Viro | 06ae43f | 2013-03-20 13:19:30 -0400 | [diff] [blame] | 1063 | ret = __kernel_write(sd->u.file, data + buf->offset, sd->len, &tmp); |
Al Viro | fbb3275 | 2014-02-02 21:09:54 -0500 | [diff] [blame] | 1064 | kunmap(buf->page); |
Miklos Szeredi | b2858d7 | 2009-05-19 11:37:46 +0200 | [diff] [blame] | 1065 | |
| 1066 | return ret; |
Miklos Szeredi | 0b0a47f | 2009-05-07 15:37:37 +0200 | [diff] [blame] | 1067 | } |
| 1068 | |
| 1069 | static ssize_t default_file_splice_write(struct pipe_inode_info *pipe, |
| 1070 | struct file *out, loff_t *ppos, |
| 1071 | size_t len, unsigned int flags) |
| 1072 | { |
Miklos Szeredi | b2858d7 | 2009-05-19 11:37:46 +0200 | [diff] [blame] | 1073 | ssize_t ret; |
Miklos Szeredi | 0b0a47f | 2009-05-07 15:37:37 +0200 | [diff] [blame] | 1074 | |
Miklos Szeredi | b2858d7 | 2009-05-19 11:37:46 +0200 | [diff] [blame] | 1075 | ret = splice_from_pipe(pipe, out, ppos, len, flags, write_pipe_buf); |
| 1076 | if (ret > 0) |
| 1077 | *ppos += ret; |
Miklos Szeredi | 0b0a47f | 2009-05-07 15:37:37 +0200 | [diff] [blame] | 1078 | |
Miklos Szeredi | b2858d7 | 2009-05-19 11:37:46 +0200 | [diff] [blame] | 1079 | return ret; |
Miklos Szeredi | 0b0a47f | 2009-05-07 15:37:37 +0200 | [diff] [blame] | 1080 | } |
| 1081 | |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 1082 | /** |
| 1083 | * generic_splice_sendpage - splice data from a pipe to a socket |
Jens Axboe | 932cc6d | 2007-06-21 13:10:21 +0200 | [diff] [blame] | 1084 | * @pipe: pipe to splice from |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 1085 | * @out: socket to write to |
Jens Axboe | 932cc6d | 2007-06-21 13:10:21 +0200 | [diff] [blame] | 1086 | * @ppos: position in @out |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 1087 | * @len: number of bytes to splice |
| 1088 | * @flags: splice modifier flags |
| 1089 | * |
Jens Axboe | 932cc6d | 2007-06-21 13:10:21 +0200 | [diff] [blame] | 1090 | * Description: |
| 1091 | * Will send @len bytes from the pipe to a network socket. No data copying |
| 1092 | * is involved. |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 1093 | * |
| 1094 | */ |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 1095 | ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, struct file *out, |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 1096 | loff_t *ppos, size_t len, unsigned int flags) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1097 | { |
Jens Axboe | 00522fb | 2006-04-26 14:39:29 +0200 | [diff] [blame] | 1098 | return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_sendpage); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1099 | } |
| 1100 | |
Jens Axboe | 059a8f3 | 2006-04-02 23:06:05 +0200 | [diff] [blame] | 1101 | EXPORT_SYMBOL(generic_splice_sendpage); |
Jeff Garzik | a0f0678 | 2006-03-30 23:06:13 -0500 | [diff] [blame] | 1102 | |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 1103 | /* |
| 1104 | * Attempt to initiate a splice from pipe to file. |
| 1105 | */ |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 1106 | static long do_splice_from(struct pipe_inode_info *pipe, struct file *out, |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 1107 | loff_t *ppos, size_t len, unsigned int flags) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1108 | { |
Miklos Szeredi | 0b0a47f | 2009-05-07 15:37:37 +0200 | [diff] [blame] | 1109 | ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, |
| 1110 | loff_t *, size_t, unsigned int); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1111 | |
Al Viro | 72c2d53 | 2013-09-22 16:27:52 -0400 | [diff] [blame] | 1112 | if (out->f_op->splice_write) |
Changli Gao | cc56f7d | 2009-11-04 09:09:52 +0100 | [diff] [blame] | 1113 | splice_write = out->f_op->splice_write; |
| 1114 | else |
Miklos Szeredi | 0b0a47f | 2009-05-07 15:37:37 +0200 | [diff] [blame] | 1115 | splice_write = default_file_splice_write; |
| 1116 | |
Al Viro | 500368f | 2013-05-23 20:07:11 -0400 | [diff] [blame] | 1117 | return splice_write(pipe, out, ppos, len, flags); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1118 | } |
| 1119 | |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 1120 | /* |
| 1121 | * Attempt to initiate a splice from a file to a pipe. |
| 1122 | */ |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 1123 | static long do_splice_to(struct file *in, loff_t *ppos, |
| 1124 | struct pipe_inode_info *pipe, size_t len, |
| 1125 | unsigned int flags) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1126 | { |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 1127 | ssize_t (*splice_read)(struct file *, loff_t *, |
| 1128 | struct pipe_inode_info *, size_t, unsigned int); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1129 | int ret; |
| 1130 | |
Jens Axboe | 49570e9 | 2006-04-11 13:56:09 +0200 | [diff] [blame] | 1131 | if (unlikely(!(in->f_mode & FMODE_READ))) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1132 | return -EBADF; |
| 1133 | |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 1134 | ret = rw_verify_area(READ, in, ppos, len); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1135 | if (unlikely(ret < 0)) |
| 1136 | return ret; |
| 1137 | |
Al Viro | 72c2d53 | 2013-09-22 16:27:52 -0400 | [diff] [blame] | 1138 | if (in->f_op->splice_read) |
Changli Gao | cc56f7d | 2009-11-04 09:09:52 +0100 | [diff] [blame] | 1139 | splice_read = in->f_op->splice_read; |
| 1140 | else |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 1141 | splice_read = default_file_splice_read; |
| 1142 | |
| 1143 | return splice_read(in, ppos, pipe, len, flags); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1144 | } |
| 1145 | |
Jens Axboe | 932cc6d | 2007-06-21 13:10:21 +0200 | [diff] [blame] | 1146 | /** |
| 1147 | * splice_direct_to_actor - splices data directly between two non-pipes |
| 1148 | * @in: file to splice from |
| 1149 | * @sd: actor information on where to splice to |
| 1150 | * @actor: handles the data splicing |
| 1151 | * |
| 1152 | * Description: |
| 1153 | * This is a special case helper to splice directly between two |
| 1154 | * points, without requiring an explicit pipe. Internally an allocated |
Randy Dunlap | 79685b8 | 2007-07-27 08:08:51 +0200 | [diff] [blame] | 1155 | * pipe is cached in the process, and reused during the lifetime of |
Jens Axboe | 932cc6d | 2007-06-21 13:10:21 +0200 | [diff] [blame] | 1156 | * that process. |
| 1157 | * |
Jens Axboe | c66ab6f | 2007-06-12 21:17:17 +0200 | [diff] [blame] | 1158 | */ |
| 1159 | ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd, |
| 1160 | splice_direct_actor *actor) |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1161 | { |
| 1162 | struct pipe_inode_info *pipe; |
| 1163 | long ret, bytes; |
| 1164 | umode_t i_mode; |
Jens Axboe | c66ab6f | 2007-06-12 21:17:17 +0200 | [diff] [blame] | 1165 | size_t len; |
| 1166 | int i, flags; |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1167 | |
| 1168 | /* |
| 1169 | * We require the input being a regular file, as we don't want to |
| 1170 | * randomly drop data for eg socket -> socket splicing. Use the |
| 1171 | * piped splicing for that! |
| 1172 | */ |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 1173 | i_mode = file_inode(in)->i_mode; |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1174 | if (unlikely(!S_ISREG(i_mode) && !S_ISBLK(i_mode))) |
| 1175 | return -EINVAL; |
| 1176 | |
| 1177 | /* |
| 1178 | * neither in nor out is a pipe, setup an internal pipe attached to |
| 1179 | * 'out' and transfer the wanted data from 'in' to 'out' through that |
| 1180 | */ |
| 1181 | pipe = current->splice_pipe; |
Jens Axboe | 49570e9 | 2006-04-11 13:56:09 +0200 | [diff] [blame] | 1182 | if (unlikely(!pipe)) { |
Al Viro | 7bee130 | 2013-03-21 11:04:15 -0400 | [diff] [blame] | 1183 | pipe = alloc_pipe_info(); |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1184 | if (!pipe) |
| 1185 | return -ENOMEM; |
| 1186 | |
| 1187 | /* |
| 1188 | * We don't have an immediate reader, but we'll read the stuff |
Jens Axboe | 00522fb | 2006-04-26 14:39:29 +0200 | [diff] [blame] | 1189 | * out of the pipe right after the splice_to_pipe(). So set |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1190 | * PIPE_READERS appropriately. |
| 1191 | */ |
| 1192 | pipe->readers = 1; |
| 1193 | |
| 1194 | current->splice_pipe = pipe; |
| 1195 | } |
| 1196 | |
| 1197 | /* |
Ingo Molnar | 73d62d8 | 2006-04-11 13:57:21 +0200 | [diff] [blame] | 1198 | * Do the splice. |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1199 | */ |
| 1200 | ret = 0; |
| 1201 | bytes = 0; |
Jens Axboe | c66ab6f | 2007-06-12 21:17:17 +0200 | [diff] [blame] | 1202 | len = sd->total_len; |
| 1203 | flags = sd->flags; |
| 1204 | |
| 1205 | /* |
| 1206 | * Don't block on output, we have to drain the direct pipe. |
| 1207 | */ |
| 1208 | sd->flags &= ~SPLICE_F_NONBLOCK; |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1209 | |
| 1210 | while (len) { |
Jens Axboe | 51a92c0 | 2007-07-13 14:11:43 +0200 | [diff] [blame] | 1211 | size_t read_len; |
Tom Zanussi | a82c53a | 2008-05-09 13:28:36 +0200 | [diff] [blame] | 1212 | loff_t pos = sd->pos, prev_pos = pos; |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1213 | |
Jens Axboe | bcd4f3a | 2007-07-16 14:41:49 +0200 | [diff] [blame] | 1214 | ret = do_splice_to(in, &pos, pipe, len, flags); |
Jens Axboe | 51a92c0 | 2007-07-13 14:11:43 +0200 | [diff] [blame] | 1215 | if (unlikely(ret <= 0)) |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1216 | goto out_release; |
| 1217 | |
| 1218 | read_len = ret; |
Jens Axboe | c66ab6f | 2007-06-12 21:17:17 +0200 | [diff] [blame] | 1219 | sd->total_len = read_len; |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1220 | |
| 1221 | /* |
| 1222 | * NOTE: nonblocking mode only applies to the input. We |
| 1223 | * must not do the output in nonblocking mode as then we |
| 1224 | * could get stuck data in the internal pipe: |
| 1225 | */ |
Jens Axboe | c66ab6f | 2007-06-12 21:17:17 +0200 | [diff] [blame] | 1226 | ret = actor(pipe, sd); |
Tom Zanussi | a82c53a | 2008-05-09 13:28:36 +0200 | [diff] [blame] | 1227 | if (unlikely(ret <= 0)) { |
| 1228 | sd->pos = prev_pos; |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1229 | goto out_release; |
Tom Zanussi | a82c53a | 2008-05-09 13:28:36 +0200 | [diff] [blame] | 1230 | } |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1231 | |
| 1232 | bytes += ret; |
| 1233 | len -= ret; |
Jens Axboe | bcd4f3a | 2007-07-16 14:41:49 +0200 | [diff] [blame] | 1234 | sd->pos = pos; |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1235 | |
Tom Zanussi | a82c53a | 2008-05-09 13:28:36 +0200 | [diff] [blame] | 1236 | if (ret < read_len) { |
| 1237 | sd->pos = prev_pos + ret; |
Jens Axboe | 51a92c0 | 2007-07-13 14:11:43 +0200 | [diff] [blame] | 1238 | goto out_release; |
Tom Zanussi | a82c53a | 2008-05-09 13:28:36 +0200 | [diff] [blame] | 1239 | } |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1240 | } |
| 1241 | |
Jens Axboe | 9e97198 | 2008-01-29 21:05:57 +0100 | [diff] [blame] | 1242 | done: |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1243 | pipe->nrbufs = pipe->curbuf = 0; |
Jens Axboe | 8084870 | 2008-01-30 12:24:48 +0100 | [diff] [blame] | 1244 | file_accessed(in); |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1245 | return bytes; |
| 1246 | |
| 1247 | out_release: |
| 1248 | /* |
| 1249 | * If we did an incomplete transfer we must release |
| 1250 | * the pipe buffers in question: |
| 1251 | */ |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1252 | for (i = 0; i < pipe->buffers; i++) { |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1253 | struct pipe_buffer *buf = pipe->bufs + i; |
| 1254 | |
| 1255 | if (buf->ops) { |
| 1256 | buf->ops->release(pipe, buf); |
| 1257 | buf->ops = NULL; |
| 1258 | } |
| 1259 | } |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1260 | |
Jens Axboe | 9e97198 | 2008-01-29 21:05:57 +0100 | [diff] [blame] | 1261 | if (!bytes) |
| 1262 | bytes = ret; |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1263 | |
Jens Axboe | 9e97198 | 2008-01-29 21:05:57 +0100 | [diff] [blame] | 1264 | goto done; |
Jens Axboe | c66ab6f | 2007-06-12 21:17:17 +0200 | [diff] [blame] | 1265 | } |
| 1266 | EXPORT_SYMBOL(splice_direct_to_actor); |
| 1267 | |
| 1268 | static int direct_splice_actor(struct pipe_inode_info *pipe, |
| 1269 | struct splice_desc *sd) |
| 1270 | { |
Jens Axboe | 6a14b90 | 2007-06-14 13:08:55 +0200 | [diff] [blame] | 1271 | struct file *file = sd->u.file; |
Jens Axboe | c66ab6f | 2007-06-12 21:17:17 +0200 | [diff] [blame] | 1272 | |
Al Viro | 7995bd2 | 2013-06-20 18:58:36 +0400 | [diff] [blame] | 1273 | return do_splice_from(pipe, file, sd->opos, sd->total_len, |
Changli Gao | 2cb4b05 | 2010-06-29 13:09:18 +0200 | [diff] [blame] | 1274 | sd->flags); |
Jens Axboe | c66ab6f | 2007-06-12 21:17:17 +0200 | [diff] [blame] | 1275 | } |
| 1276 | |
Jens Axboe | 932cc6d | 2007-06-21 13:10:21 +0200 | [diff] [blame] | 1277 | /** |
| 1278 | * do_splice_direct - splices data directly between two files |
| 1279 | * @in: file to splice from |
| 1280 | * @ppos: input file offset |
| 1281 | * @out: file to splice to |
Randy Dunlap | acdb37c | 2013-06-22 19:44:08 -0700 | [diff] [blame] | 1282 | * @opos: output file offset |
Jens Axboe | 932cc6d | 2007-06-21 13:10:21 +0200 | [diff] [blame] | 1283 | * @len: number of bytes to splice |
| 1284 | * @flags: splice modifier flags |
| 1285 | * |
| 1286 | * Description: |
| 1287 | * For use by do_sendfile(). splice can easily emulate sendfile, but |
| 1288 | * doing it in the application would incur an extra system call |
| 1289 | * (splice in + splice out, as compared to just sendfile()). So this helper |
| 1290 | * can splice directly through a process-private pipe. |
| 1291 | * |
| 1292 | */ |
Jens Axboe | c66ab6f | 2007-06-12 21:17:17 +0200 | [diff] [blame] | 1293 | long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, |
Al Viro | 7995bd2 | 2013-06-20 18:58:36 +0400 | [diff] [blame] | 1294 | loff_t *opos, size_t len, unsigned int flags) |
Jens Axboe | c66ab6f | 2007-06-12 21:17:17 +0200 | [diff] [blame] | 1295 | { |
| 1296 | struct splice_desc sd = { |
| 1297 | .len = len, |
| 1298 | .total_len = len, |
| 1299 | .flags = flags, |
| 1300 | .pos = *ppos, |
Jens Axboe | 6a14b90 | 2007-06-14 13:08:55 +0200 | [diff] [blame] | 1301 | .u.file = out, |
Al Viro | 7995bd2 | 2013-06-20 18:58:36 +0400 | [diff] [blame] | 1302 | .opos = opos, |
Jens Axboe | c66ab6f | 2007-06-12 21:17:17 +0200 | [diff] [blame] | 1303 | }; |
Jens Axboe | 51a92c0 | 2007-07-13 14:11:43 +0200 | [diff] [blame] | 1304 | long ret; |
Jens Axboe | c66ab6f | 2007-06-12 21:17:17 +0200 | [diff] [blame] | 1305 | |
Al Viro | 18c67cb | 2013-06-19 15:41:54 +0400 | [diff] [blame] | 1306 | if (unlikely(!(out->f_mode & FMODE_WRITE))) |
| 1307 | return -EBADF; |
| 1308 | |
| 1309 | if (unlikely(out->f_flags & O_APPEND)) |
| 1310 | return -EINVAL; |
| 1311 | |
| 1312 | ret = rw_verify_area(WRITE, out, opos, len); |
| 1313 | if (unlikely(ret < 0)) |
| 1314 | return ret; |
| 1315 | |
Jens Axboe | c66ab6f | 2007-06-12 21:17:17 +0200 | [diff] [blame] | 1316 | ret = splice_direct_to_actor(in, &sd, direct_splice_actor); |
Jens Axboe | 51a92c0 | 2007-07-13 14:11:43 +0200 | [diff] [blame] | 1317 | if (ret > 0) |
Tom Zanussi | a82c53a | 2008-05-09 13:28:36 +0200 | [diff] [blame] | 1318 | *ppos = sd.pos; |
Jens Axboe | 51a92c0 | 2007-07-13 14:11:43 +0200 | [diff] [blame] | 1319 | |
Jens Axboe | c66ab6f | 2007-06-12 21:17:17 +0200 | [diff] [blame] | 1320 | return ret; |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1321 | } |
| 1322 | |
Miklos Szeredi | 7c77f0b | 2009-05-07 15:37:35 +0200 | [diff] [blame] | 1323 | static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe, |
| 1324 | struct pipe_inode_info *opipe, |
| 1325 | size_t len, unsigned int flags); |
Jens Axboe | ddac0d3 | 2006-11-04 12:49:32 +0100 | [diff] [blame] | 1326 | |
| 1327 | /* |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 1328 | * Determine where to splice to/from. |
| 1329 | */ |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1330 | static long do_splice(struct file *in, loff_t __user *off_in, |
| 1331 | struct file *out, loff_t __user *off_out, |
| 1332 | size_t len, unsigned int flags) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1333 | { |
Miklos Szeredi | 7c77f0b | 2009-05-07 15:37:35 +0200 | [diff] [blame] | 1334 | struct pipe_inode_info *ipipe; |
| 1335 | struct pipe_inode_info *opipe; |
Al Viro | 7995bd2 | 2013-06-20 18:58:36 +0400 | [diff] [blame] | 1336 | loff_t offset; |
Jens Axboe | a4514eb | 2006-04-19 15:57:05 +0200 | [diff] [blame] | 1337 | long ret; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1338 | |
Linus Torvalds | 71993e6 | 2010-11-28 13:56:09 -0800 | [diff] [blame] | 1339 | ipipe = get_pipe_info(in); |
| 1340 | opipe = get_pipe_info(out); |
Miklos Szeredi | 7c77f0b | 2009-05-07 15:37:35 +0200 | [diff] [blame] | 1341 | |
| 1342 | if (ipipe && opipe) { |
| 1343 | if (off_in || off_out) |
| 1344 | return -ESPIPE; |
| 1345 | |
| 1346 | if (!(in->f_mode & FMODE_READ)) |
| 1347 | return -EBADF; |
| 1348 | |
| 1349 | if (!(out->f_mode & FMODE_WRITE)) |
| 1350 | return -EBADF; |
| 1351 | |
| 1352 | /* Splicing to self would be fun, but... */ |
| 1353 | if (ipipe == opipe) |
| 1354 | return -EINVAL; |
| 1355 | |
| 1356 | return splice_pipe_to_pipe(ipipe, opipe, len, flags); |
| 1357 | } |
| 1358 | |
| 1359 | if (ipipe) { |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1360 | if (off_in) |
| 1361 | return -ESPIPE; |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1362 | if (off_out) { |
Changli Gao | 19c9a49 | 2010-06-29 13:10:36 +0200 | [diff] [blame] | 1363 | if (!(out->f_mode & FMODE_PWRITE)) |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1364 | return -EINVAL; |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 1365 | if (copy_from_user(&offset, off_out, sizeof(loff_t))) |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1366 | return -EFAULT; |
Al Viro | 7995bd2 | 2013-06-20 18:58:36 +0400 | [diff] [blame] | 1367 | } else { |
| 1368 | offset = out->f_pos; |
| 1369 | } |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1370 | |
Al Viro | 18c67cb | 2013-06-19 15:41:54 +0400 | [diff] [blame] | 1371 | if (unlikely(!(out->f_mode & FMODE_WRITE))) |
| 1372 | return -EBADF; |
| 1373 | |
| 1374 | if (unlikely(out->f_flags & O_APPEND)) |
| 1375 | return -EINVAL; |
| 1376 | |
| 1377 | ret = rw_verify_area(WRITE, out, &offset, len); |
| 1378 | if (unlikely(ret < 0)) |
| 1379 | return ret; |
| 1380 | |
Al Viro | 500368f | 2013-05-23 20:07:11 -0400 | [diff] [blame] | 1381 | file_start_write(out); |
Al Viro | 7995bd2 | 2013-06-20 18:58:36 +0400 | [diff] [blame] | 1382 | ret = do_splice_from(ipipe, out, &offset, len, flags); |
Al Viro | 500368f | 2013-05-23 20:07:11 -0400 | [diff] [blame] | 1383 | file_end_write(out); |
Jens Axboe | a4514eb | 2006-04-19 15:57:05 +0200 | [diff] [blame] | 1384 | |
Al Viro | 7995bd2 | 2013-06-20 18:58:36 +0400 | [diff] [blame] | 1385 | if (!off_out) |
| 1386 | out->f_pos = offset; |
| 1387 | else if (copy_to_user(off_out, &offset, sizeof(loff_t))) |
Jens Axboe | a4514eb | 2006-04-19 15:57:05 +0200 | [diff] [blame] | 1388 | ret = -EFAULT; |
| 1389 | |
| 1390 | return ret; |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1391 | } |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1392 | |
Miklos Szeredi | 7c77f0b | 2009-05-07 15:37:35 +0200 | [diff] [blame] | 1393 | if (opipe) { |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1394 | if (off_out) |
| 1395 | return -ESPIPE; |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1396 | if (off_in) { |
Changli Gao | 19c9a49 | 2010-06-29 13:10:36 +0200 | [diff] [blame] | 1397 | if (!(in->f_mode & FMODE_PREAD)) |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1398 | return -EINVAL; |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 1399 | if (copy_from_user(&offset, off_in, sizeof(loff_t))) |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1400 | return -EFAULT; |
Al Viro | 7995bd2 | 2013-06-20 18:58:36 +0400 | [diff] [blame] | 1401 | } else { |
| 1402 | offset = in->f_pos; |
| 1403 | } |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1404 | |
Al Viro | 7995bd2 | 2013-06-20 18:58:36 +0400 | [diff] [blame] | 1405 | ret = do_splice_to(in, &offset, opipe, len, flags); |
Jens Axboe | a4514eb | 2006-04-19 15:57:05 +0200 | [diff] [blame] | 1406 | |
Al Viro | 7995bd2 | 2013-06-20 18:58:36 +0400 | [diff] [blame] | 1407 | if (!off_in) |
| 1408 | in->f_pos = offset; |
| 1409 | else if (copy_to_user(off_in, &offset, sizeof(loff_t))) |
Jens Axboe | a4514eb | 2006-04-19 15:57:05 +0200 | [diff] [blame] | 1410 | ret = -EFAULT; |
| 1411 | |
| 1412 | return ret; |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1413 | } |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1414 | |
| 1415 | return -EINVAL; |
| 1416 | } |
| 1417 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1418 | /* |
| 1419 | * Map an iov into an array of pages and offset/length tupples. With the |
| 1420 | * partial_page structure, we can map several non-contiguous ranges into |
| 1421 | * our ones pages[] map instead of splitting that operation into pieces. |
| 1422 | * Could easily be exported as a generic helper for other users, in which |
| 1423 | * case one would probably want to add a 'max_nr_pages' parameter as well. |
| 1424 | */ |
| 1425 | static int get_iovec_page_array(const struct iovec __user *iov, |
| 1426 | unsigned int nr_vecs, struct page **pages, |
Eric Dumazet | bd1a68b | 2012-04-04 11:08:51 +0200 | [diff] [blame] | 1427 | struct partial_page *partial, bool aligned, |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1428 | unsigned int pipe_buffers) |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1429 | { |
| 1430 | int buffers = 0, error = 0; |
| 1431 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1432 | while (nr_vecs) { |
| 1433 | unsigned long off, npages; |
Linus Torvalds | 7572395 | 2007-10-01 13:17:28 -0700 | [diff] [blame] | 1434 | struct iovec entry; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1435 | void __user *base; |
| 1436 | size_t len; |
| 1437 | int i; |
| 1438 | |
Linus Torvalds | 7572395 | 2007-10-01 13:17:28 -0700 | [diff] [blame] | 1439 | error = -EFAULT; |
Nick Piggin | bc40d73 | 2008-07-25 19:45:26 -0700 | [diff] [blame] | 1440 | if (copy_from_user(&entry, iov, sizeof(entry))) |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1441 | break; |
Linus Torvalds | 7572395 | 2007-10-01 13:17:28 -0700 | [diff] [blame] | 1442 | |
| 1443 | base = entry.iov_base; |
| 1444 | len = entry.iov_len; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1445 | |
| 1446 | /* |
| 1447 | * Sanity check this iovec. 0 read succeeds. |
| 1448 | */ |
Linus Torvalds | 7572395 | 2007-10-01 13:17:28 -0700 | [diff] [blame] | 1449 | error = 0; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1450 | if (unlikely(!len)) |
| 1451 | break; |
| 1452 | error = -EFAULT; |
Bastian Blank | 712a30e | 2008-02-10 16:47:57 +0200 | [diff] [blame] | 1453 | if (!access_ok(VERIFY_READ, base, len)) |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1454 | break; |
| 1455 | |
| 1456 | /* |
| 1457 | * Get this base offset and number of pages, then map |
| 1458 | * in the user pages. |
| 1459 | */ |
| 1460 | off = (unsigned long) base & ~PAGE_MASK; |
Jens Axboe | 7afa6fd | 2006-05-01 20:02:33 +0200 | [diff] [blame] | 1461 | |
| 1462 | /* |
| 1463 | * If asked for alignment, the offset must be zero and the |
| 1464 | * length a multiple of the PAGE_SIZE. |
| 1465 | */ |
| 1466 | error = -EINVAL; |
| 1467 | if (aligned && (off || len & ~PAGE_MASK)) |
| 1468 | break; |
| 1469 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1470 | npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1471 | if (npages > pipe_buffers - buffers) |
| 1472 | npages = pipe_buffers - buffers; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1473 | |
Nick Piggin | bc40d73 | 2008-07-25 19:45:26 -0700 | [diff] [blame] | 1474 | error = get_user_pages_fast((unsigned long)base, npages, |
| 1475 | 0, &pages[buffers]); |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1476 | |
| 1477 | if (unlikely(error <= 0)) |
| 1478 | break; |
| 1479 | |
| 1480 | /* |
| 1481 | * Fill this contiguous range into the partial page map. |
| 1482 | */ |
| 1483 | for (i = 0; i < error; i++) { |
Jens Axboe | 7591489 | 2006-05-02 12:57:18 +0200 | [diff] [blame] | 1484 | const int plen = min_t(size_t, len, PAGE_SIZE - off); |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1485 | |
| 1486 | partial[buffers].offset = off; |
| 1487 | partial[buffers].len = plen; |
| 1488 | |
| 1489 | off = 0; |
| 1490 | len -= plen; |
| 1491 | buffers++; |
| 1492 | } |
| 1493 | |
| 1494 | /* |
| 1495 | * We didn't complete this iov, stop here since it probably |
| 1496 | * means we have to move some of this into a pipe to |
| 1497 | * be able to continue. |
| 1498 | */ |
| 1499 | if (len) |
| 1500 | break; |
| 1501 | |
| 1502 | /* |
| 1503 | * Don't continue if we mapped fewer pages than we asked for, |
| 1504 | * or if we mapped the max number of pages that we have |
| 1505 | * room for. |
| 1506 | */ |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1507 | if (error < npages || buffers == pipe_buffers) |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1508 | break; |
| 1509 | |
| 1510 | nr_vecs--; |
| 1511 | iov++; |
| 1512 | } |
| 1513 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1514 | if (buffers) |
| 1515 | return buffers; |
| 1516 | |
| 1517 | return error; |
| 1518 | } |
| 1519 | |
Jens Axboe | 6a14b90 | 2007-06-14 13:08:55 +0200 | [diff] [blame] | 1520 | static int pipe_to_user(struct pipe_inode_info *pipe, struct pipe_buffer *buf, |
| 1521 | struct splice_desc *sd) |
| 1522 | { |
Al Viro | 6130f53 | 2014-02-03 18:19:51 -0500 | [diff] [blame] | 1523 | int n = copy_page_to_iter(buf->page, buf->offset, sd->len, sd->u.data); |
| 1524 | return n == sd->len ? n : -EFAULT; |
Jens Axboe | 6a14b90 | 2007-06-14 13:08:55 +0200 | [diff] [blame] | 1525 | } |
| 1526 | |
| 1527 | /* |
| 1528 | * For lack of a better implementation, implement vmsplice() to userspace |
| 1529 | * as a simple copy of the pipes pages to the user iov. |
| 1530 | */ |
Al Viro | 6130f53 | 2014-02-03 18:19:51 -0500 | [diff] [blame] | 1531 | static long vmsplice_to_user(struct file *file, const struct iovec __user *uiov, |
Jens Axboe | 6a14b90 | 2007-06-14 13:08:55 +0200 | [diff] [blame] | 1532 | unsigned long nr_segs, unsigned int flags) |
| 1533 | { |
| 1534 | struct pipe_inode_info *pipe; |
| 1535 | struct splice_desc sd; |
Jens Axboe | 6a14b90 | 2007-06-14 13:08:55 +0200 | [diff] [blame] | 1536 | long ret; |
Al Viro | 6130f53 | 2014-02-03 18:19:51 -0500 | [diff] [blame] | 1537 | struct iovec iovstack[UIO_FASTIOV]; |
| 1538 | struct iovec *iov = iovstack; |
| 1539 | struct iov_iter iter; |
Miklos Szeredi | b6dd6f4 | 2014-05-27 16:41:16 +0200 | [diff] [blame] | 1540 | ssize_t count; |
Jens Axboe | 6a14b90 | 2007-06-14 13:08:55 +0200 | [diff] [blame] | 1541 | |
Linus Torvalds | 71993e6 | 2010-11-28 13:56:09 -0800 | [diff] [blame] | 1542 | pipe = get_pipe_info(file); |
Jens Axboe | 6a14b90 | 2007-06-14 13:08:55 +0200 | [diff] [blame] | 1543 | if (!pipe) |
| 1544 | return -EBADF; |
| 1545 | |
Al Viro | 6130f53 | 2014-02-03 18:19:51 -0500 | [diff] [blame] | 1546 | ret = rw_copy_check_uvector(READ, uiov, nr_segs, |
| 1547 | ARRAY_SIZE(iovstack), iovstack, &iov); |
| 1548 | if (ret <= 0) |
Miklos Szeredi | b6dd6f4 | 2014-05-27 16:41:16 +0200 | [diff] [blame] | 1549 | goto out; |
Al Viro | 6130f53 | 2014-02-03 18:19:51 -0500 | [diff] [blame] | 1550 | |
Miklos Szeredi | b6dd6f4 | 2014-05-27 16:41:16 +0200 | [diff] [blame] | 1551 | count = ret; |
Al Viro | 6130f53 | 2014-02-03 18:19:51 -0500 | [diff] [blame] | 1552 | iov_iter_init(&iter, iov, nr_segs, count, 0); |
| 1553 | |
| 1554 | sd.len = 0; |
| 1555 | sd.total_len = count; |
| 1556 | sd.flags = flags; |
| 1557 | sd.u.data = &iter; |
| 1558 | sd.pos = 0; |
| 1559 | |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 1560 | pipe_lock(pipe); |
Al Viro | 6130f53 | 2014-02-03 18:19:51 -0500 | [diff] [blame] | 1561 | ret = __splice_from_pipe(pipe, &sd, pipe_to_user); |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 1562 | pipe_unlock(pipe); |
Jens Axboe | 6a14b90 | 2007-06-14 13:08:55 +0200 | [diff] [blame] | 1563 | |
Miklos Szeredi | b6dd6f4 | 2014-05-27 16:41:16 +0200 | [diff] [blame] | 1564 | out: |
Al Viro | 6130f53 | 2014-02-03 18:19:51 -0500 | [diff] [blame] | 1565 | if (iov != iovstack) |
| 1566 | kfree(iov); |
Jens Axboe | 6a14b90 | 2007-06-14 13:08:55 +0200 | [diff] [blame] | 1567 | |
| 1568 | return ret; |
| 1569 | } |
| 1570 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1571 | /* |
| 1572 | * vmsplice splices a user address range into a pipe. It can be thought of |
| 1573 | * as splice-from-memory, where the regular splice is splice-from-file (or |
| 1574 | * to file). In both cases the output is a pipe, naturally. |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1575 | */ |
Jens Axboe | 6a14b90 | 2007-06-14 13:08:55 +0200 | [diff] [blame] | 1576 | static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov, |
| 1577 | unsigned long nr_segs, unsigned int flags) |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1578 | { |
Jens Axboe | ddac0d3 | 2006-11-04 12:49:32 +0100 | [diff] [blame] | 1579 | struct pipe_inode_info *pipe; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1580 | struct page *pages[PIPE_DEF_BUFFERS]; |
| 1581 | struct partial_page partial[PIPE_DEF_BUFFERS]; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1582 | struct splice_pipe_desc spd = { |
| 1583 | .pages = pages, |
| 1584 | .partial = partial, |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 1585 | .nr_pages_max = PIPE_DEF_BUFFERS, |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1586 | .flags = flags, |
| 1587 | .ops = &user_page_pipe_buf_ops, |
Jens Axboe | bbdfc2f | 2007-11-06 23:29:47 -0800 | [diff] [blame] | 1588 | .spd_release = spd_release_page, |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1589 | }; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1590 | long ret; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1591 | |
Linus Torvalds | 71993e6 | 2010-11-28 13:56:09 -0800 | [diff] [blame] | 1592 | pipe = get_pipe_info(file); |
Jens Axboe | ddac0d3 | 2006-11-04 12:49:32 +0100 | [diff] [blame] | 1593 | if (!pipe) |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1594 | return -EBADF; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1595 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1596 | if (splice_grow_spd(pipe, &spd)) |
| 1597 | return -ENOMEM; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1598 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1599 | spd.nr_pages = get_iovec_page_array(iov, nr_segs, spd.pages, |
Eric Dumazet | bd1a68b | 2012-04-04 11:08:51 +0200 | [diff] [blame] | 1600 | spd.partial, false, |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 1601 | spd.nr_pages_max); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1602 | if (spd.nr_pages <= 0) |
| 1603 | ret = spd.nr_pages; |
| 1604 | else |
| 1605 | ret = splice_to_pipe(pipe, &spd); |
| 1606 | |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 1607 | splice_shrink_spd(&spd); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1608 | return ret; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1609 | } |
| 1610 | |
Jens Axboe | 6a14b90 | 2007-06-14 13:08:55 +0200 | [diff] [blame] | 1611 | /* |
| 1612 | * Note that vmsplice only really supports true splicing _from_ user memory |
| 1613 | * to a pipe, not the other way around. Splicing from user memory is a simple |
| 1614 | * operation that can be supported without any funky alignment restrictions |
| 1615 | * or nasty vm tricks. We simply map in the user memory and fill them into |
| 1616 | * a pipe. The reverse isn't quite as easy, though. There are two possible |
| 1617 | * solutions for that: |
| 1618 | * |
| 1619 | * - memcpy() the data internally, at which point we might as well just |
| 1620 | * do a regular read() on the buffer anyway. |
| 1621 | * - Lots of nasty vm tricks, that are neither fast nor flexible (it |
| 1622 | * has restriction limitations on both ends of the pipe). |
| 1623 | * |
| 1624 | * Currently we punt and implement it as a normal copy, see pipe_to_user(). |
| 1625 | * |
| 1626 | */ |
Heiko Carstens | 836f92a | 2009-01-14 14:14:33 +0100 | [diff] [blame] | 1627 | SYSCALL_DEFINE4(vmsplice, int, fd, const struct iovec __user *, iov, |
| 1628 | unsigned long, nr_segs, unsigned int, flags) |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1629 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1630 | struct fd f; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1631 | long error; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1632 | |
Jens Axboe | 6a14b90 | 2007-06-14 13:08:55 +0200 | [diff] [blame] | 1633 | if (unlikely(nr_segs > UIO_MAXIOV)) |
| 1634 | return -EINVAL; |
| 1635 | else if (unlikely(!nr_segs)) |
| 1636 | return 0; |
| 1637 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1638 | error = -EBADF; |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1639 | f = fdget(fd); |
| 1640 | if (f.file) { |
| 1641 | if (f.file->f_mode & FMODE_WRITE) |
| 1642 | error = vmsplice_to_pipe(f.file, iov, nr_segs, flags); |
| 1643 | else if (f.file->f_mode & FMODE_READ) |
| 1644 | error = vmsplice_to_user(f.file, iov, nr_segs, flags); |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1645 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1646 | fdput(f); |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1647 | } |
| 1648 | |
| 1649 | return error; |
| 1650 | } |
| 1651 | |
Al Viro | 76b021d | 2013-03-02 10:19:56 -0500 | [diff] [blame] | 1652 | #ifdef CONFIG_COMPAT |
| 1653 | COMPAT_SYSCALL_DEFINE4(vmsplice, int, fd, const struct compat_iovec __user *, iov32, |
| 1654 | unsigned int, nr_segs, unsigned int, flags) |
| 1655 | { |
| 1656 | unsigned i; |
| 1657 | struct iovec __user *iov; |
| 1658 | if (nr_segs > UIO_MAXIOV) |
| 1659 | return -EINVAL; |
| 1660 | iov = compat_alloc_user_space(nr_segs * sizeof(struct iovec)); |
| 1661 | for (i = 0; i < nr_segs; i++) { |
| 1662 | struct compat_iovec v; |
| 1663 | if (get_user(v.iov_base, &iov32[i].iov_base) || |
| 1664 | get_user(v.iov_len, &iov32[i].iov_len) || |
| 1665 | put_user(compat_ptr(v.iov_base), &iov[i].iov_base) || |
| 1666 | put_user(v.iov_len, &iov[i].iov_len)) |
| 1667 | return -EFAULT; |
| 1668 | } |
| 1669 | return sys_vmsplice(fd, iov, nr_segs, flags); |
| 1670 | } |
| 1671 | #endif |
| 1672 | |
Heiko Carstens | 836f92a | 2009-01-14 14:14:33 +0100 | [diff] [blame] | 1673 | SYSCALL_DEFINE6(splice, int, fd_in, loff_t __user *, off_in, |
| 1674 | int, fd_out, loff_t __user *, off_out, |
| 1675 | size_t, len, unsigned int, flags) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1676 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1677 | struct fd in, out; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1678 | long error; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1679 | |
| 1680 | if (unlikely(!len)) |
| 1681 | return 0; |
| 1682 | |
| 1683 | error = -EBADF; |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1684 | in = fdget(fd_in); |
| 1685 | if (in.file) { |
| 1686 | if (in.file->f_mode & FMODE_READ) { |
| 1687 | out = fdget(fd_out); |
| 1688 | if (out.file) { |
| 1689 | if (out.file->f_mode & FMODE_WRITE) |
| 1690 | error = do_splice(in.file, off_in, |
| 1691 | out.file, off_out, |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1692 | len, flags); |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1693 | fdput(out); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1694 | } |
| 1695 | } |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 1696 | fdput(in); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1697 | } |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1698 | return error; |
| 1699 | } |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1700 | |
| 1701 | /* |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1702 | * Make sure there's data to read. Wait for input if we can, otherwise |
| 1703 | * return an appropriate error. |
| 1704 | */ |
Miklos Szeredi | 7c77f0b | 2009-05-07 15:37:35 +0200 | [diff] [blame] | 1705 | static int ipipe_prep(struct pipe_inode_info *pipe, unsigned int flags) |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1706 | { |
| 1707 | int ret; |
| 1708 | |
| 1709 | /* |
| 1710 | * Check ->nrbufs without the inode lock first. This function |
| 1711 | * is speculative anyways, so missing one is ok. |
| 1712 | */ |
| 1713 | if (pipe->nrbufs) |
| 1714 | return 0; |
| 1715 | |
| 1716 | ret = 0; |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 1717 | pipe_lock(pipe); |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1718 | |
| 1719 | while (!pipe->nrbufs) { |
| 1720 | if (signal_pending(current)) { |
| 1721 | ret = -ERESTARTSYS; |
| 1722 | break; |
| 1723 | } |
| 1724 | if (!pipe->writers) |
| 1725 | break; |
| 1726 | if (!pipe->waiting_writers) { |
| 1727 | if (flags & SPLICE_F_NONBLOCK) { |
| 1728 | ret = -EAGAIN; |
| 1729 | break; |
| 1730 | } |
| 1731 | } |
| 1732 | pipe_wait(pipe); |
| 1733 | } |
| 1734 | |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 1735 | pipe_unlock(pipe); |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1736 | return ret; |
| 1737 | } |
| 1738 | |
| 1739 | /* |
| 1740 | * Make sure there's writeable room. Wait for room if we can, otherwise |
| 1741 | * return an appropriate error. |
| 1742 | */ |
Miklos Szeredi | 7c77f0b | 2009-05-07 15:37:35 +0200 | [diff] [blame] | 1743 | static int opipe_prep(struct pipe_inode_info *pipe, unsigned int flags) |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1744 | { |
| 1745 | int ret; |
| 1746 | |
| 1747 | /* |
| 1748 | * Check ->nrbufs without the inode lock first. This function |
| 1749 | * is speculative anyways, so missing one is ok. |
| 1750 | */ |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1751 | if (pipe->nrbufs < pipe->buffers) |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1752 | return 0; |
| 1753 | |
| 1754 | ret = 0; |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 1755 | pipe_lock(pipe); |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1756 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1757 | while (pipe->nrbufs >= pipe->buffers) { |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1758 | if (!pipe->readers) { |
| 1759 | send_sig(SIGPIPE, current, 0); |
| 1760 | ret = -EPIPE; |
| 1761 | break; |
| 1762 | } |
| 1763 | if (flags & SPLICE_F_NONBLOCK) { |
| 1764 | ret = -EAGAIN; |
| 1765 | break; |
| 1766 | } |
| 1767 | if (signal_pending(current)) { |
| 1768 | ret = -ERESTARTSYS; |
| 1769 | break; |
| 1770 | } |
| 1771 | pipe->waiting_writers++; |
| 1772 | pipe_wait(pipe); |
| 1773 | pipe->waiting_writers--; |
| 1774 | } |
| 1775 | |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 1776 | pipe_unlock(pipe); |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1777 | return ret; |
| 1778 | } |
| 1779 | |
| 1780 | /* |
Miklos Szeredi | 7c77f0b | 2009-05-07 15:37:35 +0200 | [diff] [blame] | 1781 | * Splice contents of ipipe to opipe. |
| 1782 | */ |
| 1783 | static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe, |
| 1784 | struct pipe_inode_info *opipe, |
| 1785 | size_t len, unsigned int flags) |
| 1786 | { |
| 1787 | struct pipe_buffer *ibuf, *obuf; |
| 1788 | int ret = 0, nbuf; |
| 1789 | bool input_wakeup = false; |
| 1790 | |
| 1791 | |
| 1792 | retry: |
| 1793 | ret = ipipe_prep(ipipe, flags); |
| 1794 | if (ret) |
| 1795 | return ret; |
| 1796 | |
| 1797 | ret = opipe_prep(opipe, flags); |
| 1798 | if (ret) |
| 1799 | return ret; |
| 1800 | |
| 1801 | /* |
| 1802 | * Potential ABBA deadlock, work around it by ordering lock |
| 1803 | * grabbing by pipe info address. Otherwise two different processes |
| 1804 | * could deadlock (one doing tee from A -> B, the other from B -> A). |
| 1805 | */ |
| 1806 | pipe_double_lock(ipipe, opipe); |
| 1807 | |
| 1808 | do { |
| 1809 | if (!opipe->readers) { |
| 1810 | send_sig(SIGPIPE, current, 0); |
| 1811 | if (!ret) |
| 1812 | ret = -EPIPE; |
| 1813 | break; |
| 1814 | } |
| 1815 | |
| 1816 | if (!ipipe->nrbufs && !ipipe->writers) |
| 1817 | break; |
| 1818 | |
| 1819 | /* |
| 1820 | * Cannot make any progress, because either the input |
| 1821 | * pipe is empty or the output pipe is full. |
| 1822 | */ |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1823 | if (!ipipe->nrbufs || opipe->nrbufs >= opipe->buffers) { |
Miklos Szeredi | 7c77f0b | 2009-05-07 15:37:35 +0200 | [diff] [blame] | 1824 | /* Already processed some buffers, break */ |
| 1825 | if (ret) |
| 1826 | break; |
| 1827 | |
| 1828 | if (flags & SPLICE_F_NONBLOCK) { |
| 1829 | ret = -EAGAIN; |
| 1830 | break; |
| 1831 | } |
| 1832 | |
| 1833 | /* |
| 1834 | * We raced with another reader/writer and haven't |
| 1835 | * managed to process any buffers. A zero return |
| 1836 | * value means EOF, so retry instead. |
| 1837 | */ |
| 1838 | pipe_unlock(ipipe); |
| 1839 | pipe_unlock(opipe); |
| 1840 | goto retry; |
| 1841 | } |
| 1842 | |
| 1843 | ibuf = ipipe->bufs + ipipe->curbuf; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1844 | nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1); |
Miklos Szeredi | 7c77f0b | 2009-05-07 15:37:35 +0200 | [diff] [blame] | 1845 | obuf = opipe->bufs + nbuf; |
| 1846 | |
| 1847 | if (len >= ibuf->len) { |
| 1848 | /* |
| 1849 | * Simply move the whole buffer from ipipe to opipe |
| 1850 | */ |
| 1851 | *obuf = *ibuf; |
| 1852 | ibuf->ops = NULL; |
| 1853 | opipe->nrbufs++; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1854 | ipipe->curbuf = (ipipe->curbuf + 1) & (ipipe->buffers - 1); |
Miklos Szeredi | 7c77f0b | 2009-05-07 15:37:35 +0200 | [diff] [blame] | 1855 | ipipe->nrbufs--; |
| 1856 | input_wakeup = true; |
| 1857 | } else { |
| 1858 | /* |
| 1859 | * Get a reference to this pipe buffer, |
| 1860 | * so we can copy the contents over. |
| 1861 | */ |
| 1862 | ibuf->ops->get(ipipe, ibuf); |
| 1863 | *obuf = *ibuf; |
| 1864 | |
| 1865 | /* |
| 1866 | * Don't inherit the gift flag, we need to |
| 1867 | * prevent multiple steals of this page. |
| 1868 | */ |
| 1869 | obuf->flags &= ~PIPE_BUF_FLAG_GIFT; |
| 1870 | |
| 1871 | obuf->len = len; |
| 1872 | opipe->nrbufs++; |
| 1873 | ibuf->offset += obuf->len; |
| 1874 | ibuf->len -= obuf->len; |
| 1875 | } |
| 1876 | ret += obuf->len; |
| 1877 | len -= obuf->len; |
| 1878 | } while (len); |
| 1879 | |
| 1880 | pipe_unlock(ipipe); |
| 1881 | pipe_unlock(opipe); |
| 1882 | |
| 1883 | /* |
| 1884 | * If we put data in the output pipe, wakeup any potential readers. |
| 1885 | */ |
Namhyung Kim | 825cdcb | 2011-05-23 19:58:53 +0200 | [diff] [blame] | 1886 | if (ret > 0) |
| 1887 | wakeup_pipe_readers(opipe); |
| 1888 | |
Miklos Szeredi | 7c77f0b | 2009-05-07 15:37:35 +0200 | [diff] [blame] | 1889 | if (input_wakeup) |
| 1890 | wakeup_pipe_writers(ipipe); |
| 1891 | |
| 1892 | return ret; |
| 1893 | } |
| 1894 | |
| 1895 | /* |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1896 | * Link contents of ipipe to opipe. |
| 1897 | */ |
| 1898 | static int link_pipe(struct pipe_inode_info *ipipe, |
| 1899 | struct pipe_inode_info *opipe, |
| 1900 | size_t len, unsigned int flags) |
| 1901 | { |
| 1902 | struct pipe_buffer *ibuf, *obuf; |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1903 | int ret = 0, i = 0, nbuf; |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1904 | |
| 1905 | /* |
| 1906 | * Potential ABBA deadlock, work around it by ordering lock |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 1907 | * grabbing by pipe info address. Otherwise two different processes |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1908 | * could deadlock (one doing tee from A -> B, the other from B -> A). |
| 1909 | */ |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 1910 | pipe_double_lock(ipipe, opipe); |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1911 | |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1912 | do { |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1913 | if (!opipe->readers) { |
| 1914 | send_sig(SIGPIPE, current, 0); |
| 1915 | if (!ret) |
| 1916 | ret = -EPIPE; |
| 1917 | break; |
| 1918 | } |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1919 | |
| 1920 | /* |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1921 | * If we have iterated all input buffers or ran out of |
| 1922 | * output room, break. |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1923 | */ |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1924 | if (i >= ipipe->nrbufs || opipe->nrbufs >= opipe->buffers) |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1925 | break; |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1926 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1927 | ibuf = ipipe->bufs + ((ipipe->curbuf + i) & (ipipe->buffers-1)); |
| 1928 | nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1); |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1929 | |
Jens Axboe | 2a27250e | 2006-04-19 15:56:40 +0200 | [diff] [blame] | 1930 | /* |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1931 | * Get a reference to this pipe buffer, |
| 1932 | * so we can copy the contents over. |
Jens Axboe | 2a27250e | 2006-04-19 15:56:40 +0200 | [diff] [blame] | 1933 | */ |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1934 | ibuf->ops->get(ipipe, ibuf); |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1935 | |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1936 | obuf = opipe->bufs + nbuf; |
| 1937 | *obuf = *ibuf; |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1938 | |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1939 | /* |
| 1940 | * Don't inherit the gift flag, we need to |
| 1941 | * prevent multiple steals of this page. |
| 1942 | */ |
| 1943 | obuf->flags &= ~PIPE_BUF_FLAG_GIFT; |
| 1944 | |
| 1945 | if (obuf->len > len) |
| 1946 | obuf->len = len; |
| 1947 | |
| 1948 | opipe->nrbufs++; |
| 1949 | ret += obuf->len; |
| 1950 | len -= obuf->len; |
| 1951 | i++; |
| 1952 | } while (len); |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1953 | |
Jens Axboe | 02cf01a | 2008-02-20 10:34:51 +0100 | [diff] [blame] | 1954 | /* |
| 1955 | * return EAGAIN if we have the potential of some data in the |
| 1956 | * future, otherwise just return 0 |
| 1957 | */ |
| 1958 | if (!ret && ipipe->waiting_writers && (flags & SPLICE_F_NONBLOCK)) |
| 1959 | ret = -EAGAIN; |
| 1960 | |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 1961 | pipe_unlock(ipipe); |
| 1962 | pipe_unlock(opipe); |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1963 | |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1964 | /* |
| 1965 | * If we put data in the output pipe, wakeup any potential readers. |
| 1966 | */ |
Namhyung Kim | 825cdcb | 2011-05-23 19:58:53 +0200 | [diff] [blame] | 1967 | if (ret > 0) |
| 1968 | wakeup_pipe_readers(opipe); |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1969 | |
| 1970 | return ret; |
| 1971 | } |
| 1972 | |
| 1973 | /* |
| 1974 | * This is a tee(1) implementation that works on pipes. It doesn't copy |
| 1975 | * any data, it simply references the 'in' pages on the 'out' pipe. |
| 1976 | * The 'flags' used are the SPLICE_F_* variants, currently the only |
| 1977 | * applicable one is SPLICE_F_NONBLOCK. |
| 1978 | */ |
| 1979 | static long do_tee(struct file *in, struct file *out, size_t len, |
| 1980 | unsigned int flags) |
| 1981 | { |
Linus Torvalds | 71993e6 | 2010-11-28 13:56:09 -0800 | [diff] [blame] | 1982 | struct pipe_inode_info *ipipe = get_pipe_info(in); |
| 1983 | struct pipe_inode_info *opipe = get_pipe_info(out); |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1984 | int ret = -EINVAL; |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1985 | |
| 1986 | /* |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1987 | * Duplicate the contents of ipipe to opipe without actually |
| 1988 | * copying the data. |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1989 | */ |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1990 | if (ipipe && opipe && ipipe != opipe) { |
| 1991 | /* |
| 1992 | * Keep going, unless we encounter an error. The ipipe/opipe |
| 1993 | * ordering doesn't really matter. |
| 1994 | */ |
Miklos Szeredi | 7c77f0b | 2009-05-07 15:37:35 +0200 | [diff] [blame] | 1995 | ret = ipipe_prep(ipipe, flags); |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1996 | if (!ret) { |
Miklos Szeredi | 7c77f0b | 2009-05-07 15:37:35 +0200 | [diff] [blame] | 1997 | ret = opipe_prep(opipe, flags); |
Jens Axboe | 02cf01a | 2008-02-20 10:34:51 +0100 | [diff] [blame] | 1998 | if (!ret) |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 1999 | ret = link_pipe(ipipe, opipe, len, flags); |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 2000 | } |
| 2001 | } |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 2002 | |
Jens Axboe | aadd06e | 2006-07-10 11:00:01 +0200 | [diff] [blame] | 2003 | return ret; |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 2004 | } |
| 2005 | |
Heiko Carstens | 836f92a | 2009-01-14 14:14:33 +0100 | [diff] [blame] | 2006 | SYSCALL_DEFINE4(tee, int, fdin, int, fdout, size_t, len, unsigned int, flags) |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 2007 | { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 2008 | struct fd in; |
| 2009 | int error; |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 2010 | |
| 2011 | if (unlikely(!len)) |
| 2012 | return 0; |
| 2013 | |
| 2014 | error = -EBADF; |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 2015 | in = fdget(fdin); |
| 2016 | if (in.file) { |
| 2017 | if (in.file->f_mode & FMODE_READ) { |
| 2018 | struct fd out = fdget(fdout); |
| 2019 | if (out.file) { |
| 2020 | if (out.file->f_mode & FMODE_WRITE) |
| 2021 | error = do_tee(in.file, out.file, |
| 2022 | len, flags); |
| 2023 | fdput(out); |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 2024 | } |
| 2025 | } |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 2026 | fdput(in); |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 2027 | } |
| 2028 | |
| 2029 | return error; |
| 2030 | } |