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 | c2058e0 | 2006-04-11 13:56:34 +0200 | [diff] [blame] | 15 | * Copyright (C) 2005-2006 Jens Axboe <axboe@suse.de> |
| 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> |
| 23 | #include <linux/pipe_fs_i.h> |
| 24 | #include <linux/mm_inline.h> |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 25 | #include <linux/swap.h> |
Jens Axboe | 4f6f0bd | 2006-04-02 23:04:46 +0200 | [diff] [blame] | 26 | #include <linux/writeback.h> |
| 27 | #include <linux/buffer_head.h> |
Jeff Garzik | a0f0678 | 2006-03-30 23:06:13 -0500 | [diff] [blame] | 28 | #include <linux/module.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> |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 31 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 32 | struct partial_page { |
| 33 | unsigned int offset; |
| 34 | unsigned int len; |
| 35 | }; |
| 36 | |
| 37 | /* |
Jens Axboe | 00522fb | 2006-04-26 14:39:29 +0200 | [diff] [blame^] | 38 | * Passed to splice_to_pipe |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 39 | */ |
| 40 | struct splice_pipe_desc { |
| 41 | struct page **pages; /* page map */ |
| 42 | struct partial_page *partial; /* pages[] may not be contig */ |
| 43 | int nr_pages; /* number of pages in map */ |
| 44 | unsigned int flags; /* splice flags */ |
| 45 | struct pipe_buf_operations *ops;/* ops associated with output pipe */ |
| 46 | }; |
| 47 | |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 48 | /* |
| 49 | * Attempt to steal a page from a pipe buffer. This should perhaps go into |
| 50 | * a vm helper function, it's already simplified quite a bit by the |
| 51 | * addition of remove_mapping(). If success is returned, the caller may |
| 52 | * attempt to reuse this page for another destination. |
| 53 | */ |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 54 | static int page_cache_pipe_buf_steal(struct pipe_inode_info *info, |
| 55 | struct pipe_buffer *buf) |
| 56 | { |
| 57 | struct page *page = buf->page; |
Jens Axboe | 4f6f0bd | 2006-04-02 23:04:46 +0200 | [diff] [blame] | 58 | struct address_space *mapping = page_mapping(page); |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 59 | |
Jens Axboe | 9e0267c | 2006-04-19 15:57:31 +0200 | [diff] [blame] | 60 | lock_page(page); |
| 61 | |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 62 | WARN_ON(!PageUptodate(page)); |
| 63 | |
Jens Axboe | ad8d6f0 | 2006-04-02 23:10:32 +0200 | [diff] [blame] | 64 | /* |
| 65 | * At least for ext2 with nobh option, we need to wait on writeback |
| 66 | * completing on this page, since we'll remove it from the pagecache. |
| 67 | * Otherwise truncate wont wait on the page, allowing the disk |
| 68 | * blocks to be reused by someone else before we actually wrote our |
| 69 | * data to them. fs corruption ensues. |
| 70 | */ |
| 71 | wait_on_page_writeback(page); |
| 72 | |
Jens Axboe | 4f6f0bd | 2006-04-02 23:04:46 +0200 | [diff] [blame] | 73 | if (PagePrivate(page)) |
| 74 | try_to_release_page(page, mapping_gfp_mask(mapping)); |
| 75 | |
Jens Axboe | 9e0267c | 2006-04-19 15:57:31 +0200 | [diff] [blame] | 76 | if (!remove_mapping(mapping, page)) { |
| 77 | unlock_page(page); |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 78 | return 1; |
Jens Axboe | 9e0267c | 2006-04-19 15:57:31 +0200 | [diff] [blame] | 79 | } |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 80 | |
Jens Axboe | 3e7ee3e | 2006-04-02 23:11:04 +0200 | [diff] [blame] | 81 | buf->flags |= PIPE_BUF_FLAG_STOLEN | PIPE_BUF_FLAG_LRU; |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 82 | return 0; |
| 83 | } |
| 84 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 85 | static void page_cache_pipe_buf_release(struct pipe_inode_info *info, |
| 86 | struct pipe_buffer *buf) |
| 87 | { |
| 88 | page_cache_release(buf->page); |
| 89 | buf->page = NULL; |
Jens Axboe | 3e7ee3e | 2006-04-02 23:11:04 +0200 | [diff] [blame] | 90 | buf->flags &= ~(PIPE_BUF_FLAG_STOLEN | PIPE_BUF_FLAG_LRU); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 91 | } |
| 92 | |
| 93 | static void *page_cache_pipe_buf_map(struct file *file, |
| 94 | struct pipe_inode_info *info, |
| 95 | struct pipe_buffer *buf) |
| 96 | { |
| 97 | struct page *page = buf->page; |
Jens Axboe | 49d0b21 | 2006-04-10 09:04:41 +0200 | [diff] [blame] | 98 | int err; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 99 | |
| 100 | if (!PageUptodate(page)) { |
Jens Axboe | 49d0b21 | 2006-04-10 09:04:41 +0200 | [diff] [blame] | 101 | lock_page(page); |
| 102 | |
| 103 | /* |
| 104 | * Page got truncated/unhashed. This will cause a 0-byte |
Ingo Molnar | 73d62d8 | 2006-04-11 13:57:21 +0200 | [diff] [blame] | 105 | * splice, if this is the first page. |
Jens Axboe | 49d0b21 | 2006-04-10 09:04:41 +0200 | [diff] [blame] | 106 | */ |
| 107 | if (!page->mapping) { |
| 108 | err = -ENODATA; |
| 109 | goto error; |
| 110 | } |
| 111 | |
| 112 | /* |
Ingo Molnar | 73d62d8 | 2006-04-11 13:57:21 +0200 | [diff] [blame] | 113 | * Uh oh, read-error from disk. |
Jens Axboe | 49d0b21 | 2006-04-10 09:04:41 +0200 | [diff] [blame] | 114 | */ |
| 115 | if (!PageUptodate(page)) { |
| 116 | err = -EIO; |
| 117 | goto error; |
| 118 | } |
| 119 | |
| 120 | /* |
Ingo Molnar | 73d62d8 | 2006-04-11 13:57:21 +0200 | [diff] [blame] | 121 | * Page is ok afterall, fall through to mapping. |
Jens Axboe | 49d0b21 | 2006-04-10 09:04:41 +0200 | [diff] [blame] | 122 | */ |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 123 | unlock_page(page); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 124 | } |
| 125 | |
Jens Axboe | 49d0b21 | 2006-04-10 09:04:41 +0200 | [diff] [blame] | 126 | return kmap(page); |
| 127 | error: |
| 128 | unlock_page(page); |
| 129 | return ERR_PTR(err); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 130 | } |
| 131 | |
| 132 | static void page_cache_pipe_buf_unmap(struct pipe_inode_info *info, |
| 133 | struct pipe_buffer *buf) |
| 134 | { |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 135 | kunmap(buf->page); |
| 136 | } |
| 137 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 138 | static void *user_page_pipe_buf_map(struct file *file, |
| 139 | struct pipe_inode_info *pipe, |
| 140 | struct pipe_buffer *buf) |
| 141 | { |
| 142 | return kmap(buf->page); |
| 143 | } |
| 144 | |
| 145 | static void user_page_pipe_buf_unmap(struct pipe_inode_info *pipe, |
| 146 | struct pipe_buffer *buf) |
| 147 | { |
| 148 | kunmap(buf->page); |
| 149 | } |
| 150 | |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 151 | static void page_cache_pipe_buf_get(struct pipe_inode_info *info, |
| 152 | struct pipe_buffer *buf) |
| 153 | { |
| 154 | page_cache_get(buf->page); |
| 155 | } |
| 156 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 157 | static struct pipe_buf_operations page_cache_pipe_buf_ops = { |
| 158 | .can_merge = 0, |
| 159 | .map = page_cache_pipe_buf_map, |
| 160 | .unmap = page_cache_pipe_buf_unmap, |
| 161 | .release = page_cache_pipe_buf_release, |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 162 | .steal = page_cache_pipe_buf_steal, |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 163 | .get = page_cache_pipe_buf_get, |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 164 | }; |
| 165 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 166 | static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe, |
| 167 | struct pipe_buffer *buf) |
| 168 | { |
| 169 | return 1; |
| 170 | } |
| 171 | |
| 172 | static struct pipe_buf_operations user_page_pipe_buf_ops = { |
| 173 | .can_merge = 0, |
| 174 | .map = user_page_pipe_buf_map, |
| 175 | .unmap = user_page_pipe_buf_unmap, |
| 176 | .release = page_cache_pipe_buf_release, |
| 177 | .steal = user_page_pipe_buf_steal, |
| 178 | .get = page_cache_pipe_buf_get, |
| 179 | }; |
| 180 | |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 181 | /* |
| 182 | * Pipe output worker. This sets up our pipe format with the page cache |
| 183 | * pipe buffer operations. Otherwise very similar to the regular pipe_writev(). |
| 184 | */ |
Jens Axboe | 00522fb | 2006-04-26 14:39:29 +0200 | [diff] [blame^] | 185 | static ssize_t splice_to_pipe(struct pipe_inode_info *pipe, |
| 186 | struct splice_pipe_desc *spd) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 187 | { |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 188 | int ret, do_wakeup, page_nr; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 189 | |
| 190 | ret = 0; |
| 191 | do_wakeup = 0; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 192 | page_nr = 0; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 193 | |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 194 | if (pipe->inode) |
| 195 | mutex_lock(&pipe->inode->i_mutex); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 196 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 197 | for (;;) { |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 198 | if (!pipe->readers) { |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 199 | send_sig(SIGPIPE, current, 0); |
| 200 | if (!ret) |
| 201 | ret = -EPIPE; |
| 202 | break; |
| 203 | } |
| 204 | |
Jens Axboe | 6f767b0 | 2006-04-11 13:53:56 +0200 | [diff] [blame] | 205 | if (pipe->nrbufs < PIPE_BUFFERS) { |
| 206 | int newbuf = (pipe->curbuf + pipe->nrbufs) & (PIPE_BUFFERS - 1); |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 207 | struct pipe_buffer *buf = pipe->bufs + newbuf; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 208 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 209 | buf->page = spd->pages[page_nr]; |
| 210 | buf->offset = spd->partial[page_nr].offset; |
| 211 | buf->len = spd->partial[page_nr].len; |
| 212 | buf->ops = spd->ops; |
Jens Axboe | 6f767b0 | 2006-04-11 13:53:56 +0200 | [diff] [blame] | 213 | pipe->nrbufs++; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 214 | page_nr++; |
| 215 | ret += buf->len; |
| 216 | |
Jens Axboe | 6f767b0 | 2006-04-11 13:53:56 +0200 | [diff] [blame] | 217 | if (pipe->inode) |
| 218 | do_wakeup = 1; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 219 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 220 | if (!--spd->nr_pages) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 221 | break; |
Jens Axboe | 6f767b0 | 2006-04-11 13:53:56 +0200 | [diff] [blame] | 222 | if (pipe->nrbufs < PIPE_BUFFERS) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 223 | continue; |
| 224 | |
| 225 | break; |
| 226 | } |
| 227 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 228 | if (spd->flags & SPLICE_F_NONBLOCK) { |
Linus Torvalds | 29e3509 | 2006-04-02 12:46:35 -0700 | [diff] [blame] | 229 | if (!ret) |
| 230 | ret = -EAGAIN; |
| 231 | break; |
| 232 | } |
| 233 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 234 | if (signal_pending(current)) { |
| 235 | if (!ret) |
| 236 | ret = -ERESTARTSYS; |
| 237 | break; |
| 238 | } |
| 239 | |
| 240 | if (do_wakeup) { |
Jens Axboe | c0bd1f6 | 2006-04-10 09:03:32 +0200 | [diff] [blame] | 241 | smp_mb(); |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 242 | if (waitqueue_active(&pipe->wait)) |
| 243 | wake_up_interruptible_sync(&pipe->wait); |
| 244 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 245 | do_wakeup = 0; |
| 246 | } |
| 247 | |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 248 | pipe->waiting_writers++; |
| 249 | pipe_wait(pipe); |
| 250 | pipe->waiting_writers--; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 251 | } |
| 252 | |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 253 | if (pipe->inode) |
| 254 | mutex_unlock(&pipe->inode->i_mutex); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 255 | |
| 256 | if (do_wakeup) { |
Jens Axboe | c0bd1f6 | 2006-04-10 09:03:32 +0200 | [diff] [blame] | 257 | smp_mb(); |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 258 | if (waitqueue_active(&pipe->wait)) |
| 259 | wake_up_interruptible(&pipe->wait); |
| 260 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 261 | } |
| 262 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 263 | while (page_nr < spd->nr_pages) |
| 264 | page_cache_release(spd->pages[page_nr++]); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 265 | |
| 266 | return ret; |
| 267 | } |
| 268 | |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 269 | static int |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 270 | __generic_file_splice_read(struct file *in, loff_t *ppos, |
| 271 | struct pipe_inode_info *pipe, size_t len, |
| 272 | unsigned int flags) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 273 | { |
| 274 | struct address_space *mapping = in->f_mapping; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 275 | unsigned int loff, nr_pages; |
Jens Axboe | 16c523d | 2006-04-10 09:03:58 +0200 | [diff] [blame] | 276 | struct page *pages[PIPE_BUFFERS]; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 277 | struct partial_page partial[PIPE_BUFFERS]; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 278 | struct page *page; |
Jens Axboe | 91ad66e | 2006-04-19 15:55:10 +0200 | [diff] [blame] | 279 | pgoff_t index, end_index; |
| 280 | loff_t isize; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 281 | size_t total_len; |
| 282 | int error; |
| 283 | struct splice_pipe_desc spd = { |
| 284 | .pages = pages, |
| 285 | .partial = partial, |
| 286 | .flags = flags, |
| 287 | .ops = &page_cache_pipe_buf_ops, |
| 288 | }; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 289 | |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 290 | index = *ppos >> PAGE_CACHE_SHIFT; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 291 | loff = *ppos & ~PAGE_CACHE_MASK; |
| 292 | nr_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 293 | |
| 294 | if (nr_pages > PIPE_BUFFERS) |
| 295 | nr_pages = PIPE_BUFFERS; |
| 296 | |
| 297 | /* |
Ingo Molnar | 73d62d8 | 2006-04-11 13:57:21 +0200 | [diff] [blame] | 298 | * Initiate read-ahead on this page range. however, don't call into |
Jens Axboe | 0b749ce | 2006-04-10 09:05:04 +0200 | [diff] [blame] | 299 | * read-ahead if this is a non-zero offset (we are likely doing small |
| 300 | * chunk splice and the page is already there) for a single page. |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 301 | */ |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 302 | if (!loff || spd.nr_pages > 1) |
| 303 | do_page_cache_readahead(mapping, in, index, spd.nr_pages); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 304 | |
| 305 | /* |
Ingo Molnar | 73d62d8 | 2006-04-11 13:57:21 +0200 | [diff] [blame] | 306 | * Now fill in the holes: |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 307 | */ |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 308 | error = 0; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 309 | total_len = 0; |
| 310 | for (spd.nr_pages = 0; spd.nr_pages < nr_pages; spd.nr_pages++, index++) { |
Jens Axboe | 82aa5d6 | 2006-04-20 13:05:48 +0200 | [diff] [blame] | 311 | unsigned int this_len; |
| 312 | |
| 313 | if (!len) |
| 314 | break; |
| 315 | |
| 316 | /* |
| 317 | * this_len is the max we'll use from this page |
| 318 | */ |
Andrew Morton | ba5f5d9 | 2006-04-25 15:33:34 +0200 | [diff] [blame] | 319 | this_len = min_t(unsigned long, len, PAGE_CACHE_SIZE - loff); |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 320 | find_page: |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 321 | /* |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 322 | * lookup the page for this index |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 323 | */ |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 324 | page = find_get_page(mapping, index); |
| 325 | if (!page) { |
| 326 | /* |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 327 | * page didn't exist, allocate one |
| 328 | */ |
| 329 | page = page_cache_alloc_cold(mapping); |
| 330 | if (!page) |
| 331 | break; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 332 | |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 333 | error = add_to_page_cache_lru(page, mapping, index, |
| 334 | mapping_gfp_mask(mapping)); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 335 | if (unlikely(error)) { |
| 336 | page_cache_release(page); |
| 337 | break; |
| 338 | } |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 339 | |
| 340 | goto readpage; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 341 | } |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 342 | |
| 343 | /* |
| 344 | * If the page isn't uptodate, we may need to start io on it |
| 345 | */ |
| 346 | if (!PageUptodate(page)) { |
Jens Axboe | c4f895c | 2006-04-19 15:56:12 +0200 | [diff] [blame] | 347 | /* |
| 348 | * If in nonblock mode then dont block on waiting |
| 349 | * for an in-flight io page |
| 350 | */ |
| 351 | if (flags & SPLICE_F_NONBLOCK) |
| 352 | break; |
| 353 | |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 354 | lock_page(page); |
| 355 | |
| 356 | /* |
| 357 | * page was truncated, stop here. if this isn't the |
| 358 | * first page, we'll just complete what we already |
| 359 | * added |
| 360 | */ |
| 361 | if (!page->mapping) { |
| 362 | unlock_page(page); |
| 363 | page_cache_release(page); |
| 364 | break; |
| 365 | } |
| 366 | /* |
| 367 | * page was already under io and is now done, great |
| 368 | */ |
| 369 | if (PageUptodate(page)) { |
| 370 | unlock_page(page); |
| 371 | goto fill_it; |
| 372 | } |
| 373 | |
| 374 | readpage: |
| 375 | /* |
| 376 | * need to read in the page |
| 377 | */ |
| 378 | error = mapping->a_ops->readpage(in, page); |
| 379 | |
| 380 | if (unlikely(error)) { |
| 381 | page_cache_release(page); |
| 382 | if (error == AOP_TRUNCATED_PAGE) |
| 383 | goto find_page; |
| 384 | break; |
| 385 | } |
Jens Axboe | 91ad66e | 2006-04-19 15:55:10 +0200 | [diff] [blame] | 386 | |
| 387 | /* |
| 388 | * i_size must be checked after ->readpage(). |
| 389 | */ |
| 390 | isize = i_size_read(mapping->host); |
| 391 | end_index = (isize - 1) >> PAGE_CACHE_SHIFT; |
| 392 | if (unlikely(!isize || index > end_index)) { |
| 393 | page_cache_release(page); |
| 394 | break; |
| 395 | } |
| 396 | |
| 397 | /* |
| 398 | * if this is the last page, see if we need to shrink |
| 399 | * the length and stop |
| 400 | */ |
| 401 | if (end_index == index) { |
| 402 | loff = PAGE_CACHE_SIZE - (isize & ~PAGE_CACHE_MASK); |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 403 | if (total_len + loff > isize) { |
Jens Axboe | 91ad66e | 2006-04-19 15:55:10 +0200 | [diff] [blame] | 404 | page_cache_release(page); |
| 405 | break; |
| 406 | } |
| 407 | /* |
| 408 | * force quit after adding this page |
| 409 | */ |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 410 | nr_pages = spd.nr_pages; |
Jens Axboe | 82aa5d6 | 2006-04-20 13:05:48 +0200 | [diff] [blame] | 411 | this_len = min(this_len, loff); |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 412 | loff = 0; |
Jens Axboe | 91ad66e | 2006-04-19 15:55:10 +0200 | [diff] [blame] | 413 | } |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 414 | } |
| 415 | fill_it: |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 416 | pages[spd.nr_pages] = page; |
| 417 | partial[spd.nr_pages].offset = loff; |
| 418 | partial[spd.nr_pages].len = this_len; |
Jens Axboe | 82aa5d6 | 2006-04-20 13:05:48 +0200 | [diff] [blame] | 419 | len -= this_len; |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 420 | total_len += this_len; |
Jens Axboe | 91ad66e | 2006-04-19 15:55:10 +0200 | [diff] [blame] | 421 | loff = 0; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 422 | } |
| 423 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 424 | if (spd.nr_pages) |
Jens Axboe | 00522fb | 2006-04-26 14:39:29 +0200 | [diff] [blame^] | 425 | return splice_to_pipe(pipe, &spd); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 426 | |
Jens Axboe | 7480a90 | 2006-04-11 13:52:47 +0200 | [diff] [blame] | 427 | return error; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 428 | } |
| 429 | |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 430 | /** |
| 431 | * generic_file_splice_read - splice data from file to a pipe |
| 432 | * @in: file to splice from |
| 433 | * @pipe: pipe to splice to |
| 434 | * @len: number of bytes to splice |
| 435 | * @flags: splice modifier flags |
| 436 | * |
| 437 | * Will read pages from given file and fill them into a pipe. |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 438 | */ |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 439 | ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, |
| 440 | struct pipe_inode_info *pipe, size_t len, |
| 441 | unsigned int flags) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 442 | { |
| 443 | ssize_t spliced; |
| 444 | int ret; |
| 445 | |
| 446 | ret = 0; |
| 447 | spliced = 0; |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 448 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 449 | while (len) { |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 450 | ret = __generic_file_splice_read(in, ppos, pipe, len, flags); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 451 | |
Jens Axboe | c4f895c | 2006-04-19 15:56:12 +0200 | [diff] [blame] | 452 | if (ret < 0) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 453 | break; |
Jens Axboe | c4f895c | 2006-04-19 15:56:12 +0200 | [diff] [blame] | 454 | else if (!ret) { |
| 455 | if (spliced) |
| 456 | break; |
| 457 | if (flags & SPLICE_F_NONBLOCK) { |
| 458 | ret = -EAGAIN; |
| 459 | break; |
| 460 | } |
| 461 | } |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 462 | |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 463 | *ppos += ret; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 464 | len -= ret; |
| 465 | spliced += ret; |
| 466 | } |
| 467 | |
| 468 | if (spliced) |
| 469 | return spliced; |
| 470 | |
| 471 | return ret; |
| 472 | } |
| 473 | |
Jens Axboe | 059a8f3 | 2006-04-02 23:06:05 +0200 | [diff] [blame] | 474 | EXPORT_SYMBOL(generic_file_splice_read); |
| 475 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 476 | /* |
Jens Axboe | 4f6f0bd | 2006-04-02 23:04:46 +0200 | [diff] [blame] | 477 | * 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] | 478 | * using sendpage(). Return the number of bytes sent. |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 479 | */ |
| 480 | static int pipe_to_sendpage(struct pipe_inode_info *info, |
| 481 | struct pipe_buffer *buf, struct splice_desc *sd) |
| 482 | { |
| 483 | struct file *file = sd->file; |
| 484 | loff_t pos = sd->pos; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 485 | ssize_t ret; |
| 486 | void *ptr; |
Jens Axboe | b2b39fa | 2006-04-02 23:05:41 +0200 | [diff] [blame] | 487 | int more; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 488 | |
| 489 | /* |
Ingo Molnar | 73d62d8 | 2006-04-11 13:57:21 +0200 | [diff] [blame] | 490 | * Sub-optimal, but we are limited by the pipe ->map. We don't |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 491 | * need a kmap'ed buffer here, we just want to make sure we |
| 492 | * have the page pinned if the pipe page originates from the |
Ingo Molnar | 73d62d8 | 2006-04-11 13:57:21 +0200 | [diff] [blame] | 493 | * page cache. |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 494 | */ |
| 495 | ptr = buf->ops->map(file, info, buf); |
| 496 | if (IS_ERR(ptr)) |
| 497 | return PTR_ERR(ptr); |
| 498 | |
Jens Axboe | b2b39fa | 2006-04-02 23:05:41 +0200 | [diff] [blame] | 499 | more = (sd->flags & SPLICE_F_MORE) || sd->len < sd->total_len; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 500 | |
Jens Axboe | 016b661 | 2006-04-25 15:42:00 +0200 | [diff] [blame] | 501 | ret = file->f_op->sendpage(file, buf->page, buf->offset, sd->len, |
| 502 | &pos, more); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 503 | |
| 504 | buf->ops->unmap(info, buf); |
Jens Axboe | 016b661 | 2006-04-25 15:42:00 +0200 | [diff] [blame] | 505 | return ret; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 506 | } |
| 507 | |
| 508 | /* |
| 509 | * This is a little more tricky than the file -> pipe splicing. There are |
| 510 | * basically three cases: |
| 511 | * |
| 512 | * - Destination page already exists in the address space and there |
| 513 | * are users of it. For that case we have no other option that |
| 514 | * copying the data. Tough luck. |
| 515 | * - Destination page already exists in the address space, but there |
| 516 | * are no users of it. Make sure it's uptodate, then drop it. Fall |
| 517 | * through to last case. |
| 518 | * - Destination page does not exist, we can add the pipe page to |
| 519 | * the page cache and avoid the copy. |
| 520 | * |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 521 | * If asked to move pages to the output file (SPLICE_F_MOVE is set in |
| 522 | * sd->flags), we attempt to migrate pages from the pipe to the output |
| 523 | * file address space page cache. This is possible if no one else has |
| 524 | * the pipe page referenced outside of the pipe and page cache. If |
| 525 | * SPLICE_F_MOVE isn't set, or we cannot move the page, we simply create |
| 526 | * 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] | 527 | */ |
| 528 | static int pipe_to_file(struct pipe_inode_info *info, struct pipe_buffer *buf, |
| 529 | struct splice_desc *sd) |
| 530 | { |
| 531 | struct file *file = sd->file; |
| 532 | struct address_space *mapping = file->f_mapping; |
Jens Axboe | 3e7ee3e | 2006-04-02 23:11:04 +0200 | [diff] [blame] | 533 | gfp_t gfp_mask = mapping_gfp_mask(mapping); |
Jens Axboe | 016b661 | 2006-04-25 15:42:00 +0200 | [diff] [blame] | 534 | unsigned int offset, this_len; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 535 | struct page *page; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 536 | pgoff_t index; |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 537 | char *src; |
Jens Axboe | 3e7ee3e | 2006-04-02 23:11:04 +0200 | [diff] [blame] | 538 | int ret; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 539 | |
| 540 | /* |
Jens Axboe | 49d0b21 | 2006-04-10 09:04:41 +0200 | [diff] [blame] | 541 | * make sure the data in this buffer is uptodate |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 542 | */ |
| 543 | src = buf->ops->map(file, info, buf); |
| 544 | if (IS_ERR(src)) |
| 545 | return PTR_ERR(src); |
| 546 | |
| 547 | index = sd->pos >> PAGE_CACHE_SHIFT; |
| 548 | offset = sd->pos & ~PAGE_CACHE_MASK; |
| 549 | |
Jens Axboe | 016b661 | 2006-04-25 15:42:00 +0200 | [diff] [blame] | 550 | this_len = sd->len; |
| 551 | if (this_len + offset > PAGE_CACHE_SIZE) |
| 552 | this_len = PAGE_CACHE_SIZE - offset; |
| 553 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 554 | /* |
Ingo Molnar | 73d62d8 | 2006-04-11 13:57:21 +0200 | [diff] [blame] | 555 | * Reuse buf page, if SPLICE_F_MOVE is set. |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 556 | */ |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 557 | if (sd->flags & SPLICE_F_MOVE) { |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 558 | /* |
| 559 | * If steal succeeds, buf->page is now pruned from the vm |
Jens Axboe | 9e0267c | 2006-04-19 15:57:31 +0200 | [diff] [blame] | 560 | * side (LRU and page cache) and we can reuse it. The page |
| 561 | * will also be looked on successful return. |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 562 | */ |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 563 | if (buf->ops->steal(info, buf)) |
| 564 | goto find_page; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 565 | |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 566 | page = buf->page; |
Jens Axboe | 3e7ee3e | 2006-04-02 23:11:04 +0200 | [diff] [blame] | 567 | if (add_to_page_cache(page, mapping, index, gfp_mask)) |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 568 | goto find_page; |
Jens Axboe | 3e7ee3e | 2006-04-02 23:11:04 +0200 | [diff] [blame] | 569 | |
| 570 | if (!(buf->flags & PIPE_BUF_FLAG_LRU)) |
| 571 | lru_cache_add(page); |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 572 | } else { |
| 573 | find_page: |
Jens Axboe | 9e0267c | 2006-04-19 15:57:31 +0200 | [diff] [blame] | 574 | page = find_lock_page(mapping, index); |
| 575 | if (!page) { |
| 576 | ret = -ENOMEM; |
| 577 | page = page_cache_alloc_cold(mapping); |
| 578 | if (unlikely(!page)) |
| 579 | goto out_nomem; |
| 580 | |
| 581 | /* |
| 582 | * This will also lock the page |
| 583 | */ |
| 584 | ret = add_to_page_cache_lru(page, mapping, index, |
| 585 | gfp_mask); |
| 586 | if (unlikely(ret)) |
| 587 | goto out; |
| 588 | } |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 589 | |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 590 | /* |
Jens Axboe | 9e0267c | 2006-04-19 15:57:31 +0200 | [diff] [blame] | 591 | * We get here with the page locked. If the page is also |
| 592 | * uptodate, we don't need to do more. If it isn't, we |
| 593 | * may need to bring it in if we are not going to overwrite |
| 594 | * the full page. |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 595 | */ |
| 596 | if (!PageUptodate(page)) { |
Jens Axboe | 016b661 | 2006-04-25 15:42:00 +0200 | [diff] [blame] | 597 | if (this_len < PAGE_CACHE_SIZE) { |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 598 | ret = mapping->a_ops->readpage(file, page); |
| 599 | if (unlikely(ret)) |
| 600 | goto out; |
| 601 | |
| 602 | lock_page(page); |
| 603 | |
| 604 | if (!PageUptodate(page)) { |
| 605 | /* |
Ingo Molnar | 73d62d8 | 2006-04-11 13:57:21 +0200 | [diff] [blame] | 606 | * Page got invalidated, repeat. |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 607 | */ |
| 608 | if (!page->mapping) { |
| 609 | unlock_page(page); |
| 610 | page_cache_release(page); |
| 611 | goto find_page; |
| 612 | } |
| 613 | ret = -EIO; |
| 614 | goto out; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 615 | } |
Jens Axboe | 9e0267c | 2006-04-19 15:57:31 +0200 | [diff] [blame] | 616 | } else |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 617 | SetPageUptodate(page); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 618 | } |
| 619 | } |
| 620 | |
Jens Axboe | 016b661 | 2006-04-25 15:42:00 +0200 | [diff] [blame] | 621 | ret = mapping->a_ops->prepare_write(file, page, offset, offset+this_len); |
Jens Axboe | 4f6f0bd | 2006-04-02 23:04:46 +0200 | [diff] [blame] | 622 | if (ret == AOP_TRUNCATED_PAGE) { |
| 623 | page_cache_release(page); |
| 624 | goto find_page; |
| 625 | } else if (ret) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 626 | goto out; |
| 627 | |
Jens Axboe | 3e7ee3e | 2006-04-02 23:11:04 +0200 | [diff] [blame] | 628 | if (!(buf->flags & PIPE_BUF_FLAG_STOLEN)) { |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 629 | char *dst = kmap_atomic(page, KM_USER0); |
| 630 | |
Jens Axboe | 016b661 | 2006-04-25 15:42:00 +0200 | [diff] [blame] | 631 | memcpy(dst + offset, src + buf->offset, this_len); |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 632 | flush_dcache_page(page); |
| 633 | kunmap_atomic(dst, KM_USER0); |
| 634 | } |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 635 | |
Jens Axboe | 016b661 | 2006-04-25 15:42:00 +0200 | [diff] [blame] | 636 | ret = mapping->a_ops->commit_write(file, page, offset, offset+this_len); |
Jens Axboe | 4f6f0bd | 2006-04-02 23:04:46 +0200 | [diff] [blame] | 637 | if (ret == AOP_TRUNCATED_PAGE) { |
| 638 | page_cache_release(page); |
| 639 | goto find_page; |
| 640 | } else if (ret) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 641 | goto out; |
| 642 | |
Jens Axboe | 016b661 | 2006-04-25 15:42:00 +0200 | [diff] [blame] | 643 | /* |
| 644 | * Return the number of bytes written. |
| 645 | */ |
| 646 | ret = this_len; |
Jens Axboe | c7f21e4 | 2006-04-10 09:01:01 +0200 | [diff] [blame] | 647 | mark_page_accessed(page); |
Jens Axboe | 4f6f0bd | 2006-04-02 23:04:46 +0200 | [diff] [blame] | 648 | balance_dirty_pages_ratelimited(mapping); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 649 | out: |
Jens Axboe | 9e0267c | 2006-04-19 15:57:31 +0200 | [diff] [blame] | 650 | if (!(buf->flags & PIPE_BUF_FLAG_STOLEN)) |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 651 | page_cache_release(page); |
Jens Axboe | 9e0267c | 2006-04-19 15:57:31 +0200 | [diff] [blame] | 652 | |
| 653 | unlock_page(page); |
Dave Jones | 9aefe43 | 2006-04-10 09:02:40 +0200 | [diff] [blame] | 654 | out_nomem: |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 655 | buf->ops->unmap(info, buf); |
| 656 | return ret; |
| 657 | } |
| 658 | |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 659 | /* |
| 660 | * Pipe input worker. Most of this logic works like a regular pipe, the |
| 661 | * key here is the 'actor' worker passed in that actually moves the data |
| 662 | * to the wanted destination. See pipe_to_file/pipe_to_sendpage above. |
| 663 | */ |
Jens Axboe | 00522fb | 2006-04-26 14:39:29 +0200 | [diff] [blame^] | 664 | ssize_t splice_from_pipe(struct pipe_inode_info *pipe, struct file *out, |
| 665 | loff_t *ppos, size_t len, unsigned int flags, |
| 666 | splice_actor *actor) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 667 | { |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 668 | int ret, do_wakeup, err; |
| 669 | struct splice_desc sd; |
| 670 | |
| 671 | ret = 0; |
| 672 | do_wakeup = 0; |
| 673 | |
| 674 | sd.total_len = len; |
| 675 | sd.flags = flags; |
| 676 | sd.file = out; |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 677 | sd.pos = *ppos; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 678 | |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 679 | if (pipe->inode) |
| 680 | mutex_lock(&pipe->inode->i_mutex); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 681 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 682 | for (;;) { |
Jens Axboe | 6f767b0 | 2006-04-11 13:53:56 +0200 | [diff] [blame] | 683 | if (pipe->nrbufs) { |
| 684 | struct pipe_buffer *buf = pipe->bufs + pipe->curbuf; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 685 | struct pipe_buf_operations *ops = buf->ops; |
| 686 | |
| 687 | sd.len = buf->len; |
| 688 | if (sd.len > sd.total_len) |
| 689 | sd.len = sd.total_len; |
| 690 | |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 691 | err = actor(pipe, buf, &sd); |
Jens Axboe | 016b661 | 2006-04-25 15:42:00 +0200 | [diff] [blame] | 692 | if (err <= 0) { |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 693 | if (!ret && err != -ENODATA) |
| 694 | ret = err; |
| 695 | |
| 696 | break; |
| 697 | } |
| 698 | |
Jens Axboe | 016b661 | 2006-04-25 15:42:00 +0200 | [diff] [blame] | 699 | ret += err; |
| 700 | buf->offset += err; |
| 701 | buf->len -= err; |
| 702 | |
| 703 | sd.len -= err; |
| 704 | sd.pos += err; |
| 705 | sd.total_len -= err; |
| 706 | if (sd.len) |
| 707 | continue; |
Ingo Molnar | 73d62d8 | 2006-04-11 13:57:21 +0200 | [diff] [blame] | 708 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 709 | if (!buf->len) { |
| 710 | buf->ops = NULL; |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 711 | ops->release(pipe, buf); |
Jens Axboe | 6f767b0 | 2006-04-11 13:53:56 +0200 | [diff] [blame] | 712 | pipe->curbuf = (pipe->curbuf + 1) & (PIPE_BUFFERS - 1); |
| 713 | pipe->nrbufs--; |
| 714 | if (pipe->inode) |
| 715 | do_wakeup = 1; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 716 | } |
| 717 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 718 | if (!sd.total_len) |
| 719 | break; |
| 720 | } |
| 721 | |
Jens Axboe | 6f767b0 | 2006-04-11 13:53:56 +0200 | [diff] [blame] | 722 | if (pipe->nrbufs) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 723 | continue; |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 724 | if (!pipe->writers) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 725 | break; |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 726 | if (!pipe->waiting_writers) { |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 727 | if (ret) |
| 728 | break; |
| 729 | } |
| 730 | |
Linus Torvalds | 29e3509 | 2006-04-02 12:46:35 -0700 | [diff] [blame] | 731 | if (flags & SPLICE_F_NONBLOCK) { |
| 732 | if (!ret) |
| 733 | ret = -EAGAIN; |
| 734 | break; |
| 735 | } |
| 736 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 737 | if (signal_pending(current)) { |
| 738 | if (!ret) |
| 739 | ret = -ERESTARTSYS; |
| 740 | break; |
| 741 | } |
| 742 | |
| 743 | if (do_wakeup) { |
Jens Axboe | c0bd1f6 | 2006-04-10 09:03:32 +0200 | [diff] [blame] | 744 | smp_mb(); |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 745 | if (waitqueue_active(&pipe->wait)) |
| 746 | wake_up_interruptible_sync(&pipe->wait); |
| 747 | kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 748 | do_wakeup = 0; |
| 749 | } |
| 750 | |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 751 | pipe_wait(pipe); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 752 | } |
| 753 | |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 754 | if (pipe->inode) |
| 755 | mutex_unlock(&pipe->inode->i_mutex); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 756 | |
| 757 | if (do_wakeup) { |
Jens Axboe | c0bd1f6 | 2006-04-10 09:03:32 +0200 | [diff] [blame] | 758 | smp_mb(); |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 759 | if (waitqueue_active(&pipe->wait)) |
| 760 | wake_up_interruptible(&pipe->wait); |
| 761 | kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 762 | } |
| 763 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 764 | return ret; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 765 | } |
| 766 | |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 767 | /** |
| 768 | * generic_file_splice_write - splice data from a pipe to a file |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 769 | * @pipe: pipe info |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 770 | * @out: file to write to |
| 771 | * @len: number of bytes to splice |
| 772 | * @flags: splice modifier flags |
| 773 | * |
| 774 | * Will either move or copy pages (determined by @flags options) from |
| 775 | * the given pipe inode to the given file. |
| 776 | * |
| 777 | */ |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 778 | ssize_t |
| 779 | generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out, |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 780 | loff_t *ppos, size_t len, unsigned int flags) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 781 | { |
Jens Axboe | 4f6f0bd | 2006-04-02 23:04:46 +0200 | [diff] [blame] | 782 | struct address_space *mapping = out->f_mapping; |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 783 | ssize_t ret; |
| 784 | |
Jens Axboe | 00522fb | 2006-04-26 14:39:29 +0200 | [diff] [blame^] | 785 | ret = splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_file); |
Jens Axboe | a4514eb | 2006-04-19 15:57:05 +0200 | [diff] [blame] | 786 | if (ret > 0) { |
Jens Axboe | 4f6f0bd | 2006-04-02 23:04:46 +0200 | [diff] [blame] | 787 | struct inode *inode = mapping->host; |
Jens Axboe | 4f6f0bd | 2006-04-02 23:04:46 +0200 | [diff] [blame] | 788 | |
Jens Axboe | a4514eb | 2006-04-19 15:57:05 +0200 | [diff] [blame] | 789 | *ppos += ret; |
Jens Axboe | 4f6f0bd | 2006-04-02 23:04:46 +0200 | [diff] [blame] | 790 | |
Jens Axboe | a4514eb | 2006-04-19 15:57:05 +0200 | [diff] [blame] | 791 | /* |
| 792 | * If file or inode is SYNC and we actually wrote some data, |
| 793 | * sync it. |
| 794 | */ |
| 795 | if (unlikely((out->f_flags & O_SYNC) || IS_SYNC(inode))) { |
| 796 | int err; |
| 797 | |
| 798 | mutex_lock(&inode->i_mutex); |
| 799 | err = generic_osync_inode(inode, mapping, |
| 800 | OSYNC_METADATA|OSYNC_DATA); |
| 801 | mutex_unlock(&inode->i_mutex); |
| 802 | |
| 803 | if (err) |
| 804 | ret = err; |
| 805 | } |
Jens Axboe | 4f6f0bd | 2006-04-02 23:04:46 +0200 | [diff] [blame] | 806 | } |
| 807 | |
| 808 | return ret; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 809 | } |
| 810 | |
Jens Axboe | 059a8f3 | 2006-04-02 23:06:05 +0200 | [diff] [blame] | 811 | EXPORT_SYMBOL(generic_file_splice_write); |
| 812 | |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 813 | /** |
| 814 | * generic_splice_sendpage - splice data from a pipe to a socket |
| 815 | * @inode: pipe inode |
| 816 | * @out: socket to write to |
| 817 | * @len: number of bytes to splice |
| 818 | * @flags: splice modifier flags |
| 819 | * |
| 820 | * Will send @len bytes from the pipe to a network socket. No data copying |
| 821 | * is involved. |
| 822 | * |
| 823 | */ |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 824 | 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] | 825 | loff_t *ppos, size_t len, unsigned int flags) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 826 | { |
Jens Axboe | 00522fb | 2006-04-26 14:39:29 +0200 | [diff] [blame^] | 827 | return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_sendpage); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 828 | } |
| 829 | |
Jens Axboe | 059a8f3 | 2006-04-02 23:06:05 +0200 | [diff] [blame] | 830 | EXPORT_SYMBOL(generic_splice_sendpage); |
Jeff Garzik | a0f0678 | 2006-03-30 23:06:13 -0500 | [diff] [blame] | 831 | |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 832 | /* |
| 833 | * Attempt to initiate a splice from pipe to file. |
| 834 | */ |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 835 | 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] | 836 | loff_t *ppos, size_t len, unsigned int flags) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 837 | { |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 838 | int ret; |
| 839 | |
Jens Axboe | 49570e9 | 2006-04-11 13:56:09 +0200 | [diff] [blame] | 840 | if (unlikely(!out->f_op || !out->f_op->splice_write)) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 841 | return -EINVAL; |
| 842 | |
Jens Axboe | 49570e9 | 2006-04-11 13:56:09 +0200 | [diff] [blame] | 843 | if (unlikely(!(out->f_mode & FMODE_WRITE))) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 844 | return -EBADF; |
| 845 | |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 846 | ret = rw_verify_area(WRITE, out, ppos, len); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 847 | if (unlikely(ret < 0)) |
| 848 | return ret; |
| 849 | |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 850 | return out->f_op->splice_write(pipe, out, ppos, len, flags); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 851 | } |
| 852 | |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 853 | /* |
| 854 | * Attempt to initiate a splice from a file to a pipe. |
| 855 | */ |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 856 | static long do_splice_to(struct file *in, loff_t *ppos, |
| 857 | struct pipe_inode_info *pipe, size_t len, |
| 858 | unsigned int flags) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 859 | { |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 860 | loff_t isize, left; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 861 | int ret; |
| 862 | |
Jens Axboe | 49570e9 | 2006-04-11 13:56:09 +0200 | [diff] [blame] | 863 | if (unlikely(!in->f_op || !in->f_op->splice_read)) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 864 | return -EINVAL; |
| 865 | |
Jens Axboe | 49570e9 | 2006-04-11 13:56:09 +0200 | [diff] [blame] | 866 | if (unlikely(!(in->f_mode & FMODE_READ))) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 867 | return -EBADF; |
| 868 | |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 869 | ret = rw_verify_area(READ, in, ppos, len); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 870 | if (unlikely(ret < 0)) |
| 871 | return ret; |
| 872 | |
| 873 | isize = i_size_read(in->f_mapping->host); |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 874 | if (unlikely(*ppos >= isize)) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 875 | return 0; |
| 876 | |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 877 | left = isize - *ppos; |
Jens Axboe | 49570e9 | 2006-04-11 13:56:09 +0200 | [diff] [blame] | 878 | if (unlikely(left < len)) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 879 | len = left; |
| 880 | |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 881 | return in->f_op->splice_read(in, ppos, pipe, len, flags); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 882 | } |
| 883 | |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 884 | long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, |
| 885 | size_t len, unsigned int flags) |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 886 | { |
| 887 | struct pipe_inode_info *pipe; |
| 888 | long ret, bytes; |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 889 | loff_t out_off; |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 890 | umode_t i_mode; |
| 891 | int i; |
| 892 | |
| 893 | /* |
| 894 | * We require the input being a regular file, as we don't want to |
| 895 | * randomly drop data for eg socket -> socket splicing. Use the |
| 896 | * piped splicing for that! |
| 897 | */ |
| 898 | i_mode = in->f_dentry->d_inode->i_mode; |
| 899 | if (unlikely(!S_ISREG(i_mode) && !S_ISBLK(i_mode))) |
| 900 | return -EINVAL; |
| 901 | |
| 902 | /* |
| 903 | * neither in nor out is a pipe, setup an internal pipe attached to |
| 904 | * 'out' and transfer the wanted data from 'in' to 'out' through that |
| 905 | */ |
| 906 | pipe = current->splice_pipe; |
Jens Axboe | 49570e9 | 2006-04-11 13:56:09 +0200 | [diff] [blame] | 907 | if (unlikely(!pipe)) { |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 908 | pipe = alloc_pipe_info(NULL); |
| 909 | if (!pipe) |
| 910 | return -ENOMEM; |
| 911 | |
| 912 | /* |
| 913 | * 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^] | 914 | * out of the pipe right after the splice_to_pipe(). So set |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 915 | * PIPE_READERS appropriately. |
| 916 | */ |
| 917 | pipe->readers = 1; |
| 918 | |
| 919 | current->splice_pipe = pipe; |
| 920 | } |
| 921 | |
| 922 | /* |
Ingo Molnar | 73d62d8 | 2006-04-11 13:57:21 +0200 | [diff] [blame] | 923 | * Do the splice. |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 924 | */ |
| 925 | ret = 0; |
| 926 | bytes = 0; |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 927 | out_off = 0; |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 928 | |
| 929 | while (len) { |
| 930 | size_t read_len, max_read_len; |
| 931 | |
| 932 | /* |
| 933 | * Do at most PIPE_BUFFERS pages worth of transfer: |
| 934 | */ |
| 935 | max_read_len = min(len, (size_t)(PIPE_BUFFERS*PAGE_SIZE)); |
| 936 | |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 937 | ret = do_splice_to(in, ppos, pipe, max_read_len, flags); |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 938 | if (unlikely(ret < 0)) |
| 939 | goto out_release; |
| 940 | |
| 941 | read_len = ret; |
| 942 | |
| 943 | /* |
| 944 | * NOTE: nonblocking mode only applies to the input. We |
| 945 | * must not do the output in nonblocking mode as then we |
| 946 | * could get stuck data in the internal pipe: |
| 947 | */ |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 948 | ret = do_splice_from(pipe, out, &out_off, read_len, |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 949 | flags & ~SPLICE_F_NONBLOCK); |
| 950 | if (unlikely(ret < 0)) |
| 951 | goto out_release; |
| 952 | |
| 953 | bytes += ret; |
| 954 | len -= ret; |
| 955 | |
| 956 | /* |
| 957 | * In nonblocking mode, if we got back a short read then |
| 958 | * that was due to either an IO error or due to the |
| 959 | * pagecache entry not being there. In the IO error case |
| 960 | * the _next_ splice attempt will produce a clean IO error |
| 961 | * return value (not a short read), so in both cases it's |
| 962 | * correct to break out of the loop here: |
| 963 | */ |
| 964 | if ((flags & SPLICE_F_NONBLOCK) && (read_len < max_read_len)) |
| 965 | break; |
| 966 | } |
| 967 | |
| 968 | pipe->nrbufs = pipe->curbuf = 0; |
| 969 | |
| 970 | return bytes; |
| 971 | |
| 972 | out_release: |
| 973 | /* |
| 974 | * If we did an incomplete transfer we must release |
| 975 | * the pipe buffers in question: |
| 976 | */ |
| 977 | for (i = 0; i < PIPE_BUFFERS; i++) { |
| 978 | struct pipe_buffer *buf = pipe->bufs + i; |
| 979 | |
| 980 | if (buf->ops) { |
| 981 | buf->ops->release(pipe, buf); |
| 982 | buf->ops = NULL; |
| 983 | } |
| 984 | } |
| 985 | pipe->nrbufs = pipe->curbuf = 0; |
| 986 | |
| 987 | /* |
| 988 | * If we transferred some data, return the number of bytes: |
| 989 | */ |
| 990 | if (bytes > 0) |
| 991 | return bytes; |
| 992 | |
| 993 | return ret; |
| 994 | } |
| 995 | |
| 996 | EXPORT_SYMBOL(do_splice_direct); |
| 997 | |
Jens Axboe | 83f9135 | 2006-04-02 23:05:09 +0200 | [diff] [blame] | 998 | /* |
| 999 | * Determine where to splice to/from. |
| 1000 | */ |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1001 | static long do_splice(struct file *in, loff_t __user *off_in, |
| 1002 | struct file *out, loff_t __user *off_out, |
| 1003 | size_t len, unsigned int flags) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1004 | { |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 1005 | struct pipe_inode_info *pipe; |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 1006 | loff_t offset, *off; |
Jens Axboe | a4514eb | 2006-04-19 15:57:05 +0200 | [diff] [blame] | 1007 | long ret; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1008 | |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 1009 | pipe = in->f_dentry->d_inode->i_pipe; |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1010 | if (pipe) { |
| 1011 | if (off_in) |
| 1012 | return -ESPIPE; |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1013 | if (off_out) { |
| 1014 | if (out->f_op->llseek == no_llseek) |
| 1015 | return -EINVAL; |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 1016 | if (copy_from_user(&offset, off_out, sizeof(loff_t))) |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1017 | return -EFAULT; |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 1018 | off = &offset; |
| 1019 | } else |
| 1020 | off = &out->f_pos; |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1021 | |
Jens Axboe | a4514eb | 2006-04-19 15:57:05 +0200 | [diff] [blame] | 1022 | ret = do_splice_from(pipe, out, off, len, flags); |
| 1023 | |
| 1024 | if (off_out && copy_to_user(off_out, off, sizeof(loff_t))) |
| 1025 | ret = -EFAULT; |
| 1026 | |
| 1027 | return ret; |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1028 | } |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1029 | |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 1030 | pipe = out->f_dentry->d_inode->i_pipe; |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1031 | if (pipe) { |
| 1032 | if (off_out) |
| 1033 | return -ESPIPE; |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1034 | if (off_in) { |
| 1035 | if (in->f_op->llseek == no_llseek) |
| 1036 | return -EINVAL; |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 1037 | if (copy_from_user(&offset, off_in, sizeof(loff_t))) |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 1038 | return -EFAULT; |
Jens Axboe | cbb7e57 | 2006-04-11 14:57:50 +0200 | [diff] [blame] | 1039 | off = &offset; |
| 1040 | } else |
| 1041 | off = &in->f_pos; |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1042 | |
Jens Axboe | a4514eb | 2006-04-19 15:57:05 +0200 | [diff] [blame] | 1043 | ret = do_splice_to(in, off, pipe, len, flags); |
| 1044 | |
| 1045 | if (off_in && copy_to_user(off_in, off, sizeof(loff_t))) |
| 1046 | ret = -EFAULT; |
| 1047 | |
| 1048 | return ret; |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1049 | } |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1050 | |
| 1051 | return -EINVAL; |
| 1052 | } |
| 1053 | |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1054 | /* |
| 1055 | * Map an iov into an array of pages and offset/length tupples. With the |
| 1056 | * partial_page structure, we can map several non-contiguous ranges into |
| 1057 | * our ones pages[] map instead of splitting that operation into pieces. |
| 1058 | * Could easily be exported as a generic helper for other users, in which |
| 1059 | * case one would probably want to add a 'max_nr_pages' parameter as well. |
| 1060 | */ |
| 1061 | static int get_iovec_page_array(const struct iovec __user *iov, |
| 1062 | unsigned int nr_vecs, struct page **pages, |
| 1063 | struct partial_page *partial) |
| 1064 | { |
| 1065 | int buffers = 0, error = 0; |
| 1066 | |
| 1067 | /* |
| 1068 | * It's ok to take the mmap_sem for reading, even |
| 1069 | * across a "get_user()". |
| 1070 | */ |
| 1071 | down_read(¤t->mm->mmap_sem); |
| 1072 | |
| 1073 | while (nr_vecs) { |
| 1074 | unsigned long off, npages; |
| 1075 | void __user *base; |
| 1076 | size_t len; |
| 1077 | int i; |
| 1078 | |
| 1079 | /* |
| 1080 | * Get user address base and length for this iovec. |
| 1081 | */ |
| 1082 | error = get_user(base, &iov->iov_base); |
| 1083 | if (unlikely(error)) |
| 1084 | break; |
| 1085 | error = get_user(len, &iov->iov_len); |
| 1086 | if (unlikely(error)) |
| 1087 | break; |
| 1088 | |
| 1089 | /* |
| 1090 | * Sanity check this iovec. 0 read succeeds. |
| 1091 | */ |
| 1092 | if (unlikely(!len)) |
| 1093 | break; |
| 1094 | error = -EFAULT; |
| 1095 | if (unlikely(!base)) |
| 1096 | break; |
| 1097 | |
| 1098 | /* |
| 1099 | * Get this base offset and number of pages, then map |
| 1100 | * in the user pages. |
| 1101 | */ |
| 1102 | off = (unsigned long) base & ~PAGE_MASK; |
| 1103 | npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 1104 | if (npages > PIPE_BUFFERS - buffers) |
| 1105 | npages = PIPE_BUFFERS - buffers; |
| 1106 | |
| 1107 | error = get_user_pages(current, current->mm, |
| 1108 | (unsigned long) base, npages, 0, 0, |
| 1109 | &pages[buffers], NULL); |
| 1110 | |
| 1111 | if (unlikely(error <= 0)) |
| 1112 | break; |
| 1113 | |
| 1114 | /* |
| 1115 | * Fill this contiguous range into the partial page map. |
| 1116 | */ |
| 1117 | for (i = 0; i < error; i++) { |
| 1118 | const int plen = min_t(size_t, len, PAGE_SIZE) - off; |
| 1119 | |
| 1120 | partial[buffers].offset = off; |
| 1121 | partial[buffers].len = plen; |
| 1122 | |
| 1123 | off = 0; |
| 1124 | len -= plen; |
| 1125 | buffers++; |
| 1126 | } |
| 1127 | |
| 1128 | /* |
| 1129 | * We didn't complete this iov, stop here since it probably |
| 1130 | * means we have to move some of this into a pipe to |
| 1131 | * be able to continue. |
| 1132 | */ |
| 1133 | if (len) |
| 1134 | break; |
| 1135 | |
| 1136 | /* |
| 1137 | * Don't continue if we mapped fewer pages than we asked for, |
| 1138 | * or if we mapped the max number of pages that we have |
| 1139 | * room for. |
| 1140 | */ |
| 1141 | if (error < npages || buffers == PIPE_BUFFERS) |
| 1142 | break; |
| 1143 | |
| 1144 | nr_vecs--; |
| 1145 | iov++; |
| 1146 | } |
| 1147 | |
| 1148 | up_read(¤t->mm->mmap_sem); |
| 1149 | |
| 1150 | if (buffers) |
| 1151 | return buffers; |
| 1152 | |
| 1153 | return error; |
| 1154 | } |
| 1155 | |
| 1156 | /* |
| 1157 | * vmsplice splices a user address range into a pipe. It can be thought of |
| 1158 | * as splice-from-memory, where the regular splice is splice-from-file (or |
| 1159 | * to file). In both cases the output is a pipe, naturally. |
| 1160 | * |
| 1161 | * Note that vmsplice only supports splicing _from_ user memory to a pipe, |
| 1162 | * not the other way around. Splicing from user memory is a simple operation |
| 1163 | * that can be supported without any funky alignment restrictions or nasty |
| 1164 | * vm tricks. We simply map in the user memory and fill them into a pipe. |
| 1165 | * The reverse isn't quite as easy, though. There are two possible solutions |
| 1166 | * for that: |
| 1167 | * |
| 1168 | * - memcpy() the data internally, at which point we might as well just |
| 1169 | * do a regular read() on the buffer anyway. |
| 1170 | * - Lots of nasty vm tricks, that are neither fast nor flexible (it |
| 1171 | * has restriction limitations on both ends of the pipe). |
| 1172 | * |
| 1173 | * Alas, it isn't here. |
| 1174 | * |
| 1175 | */ |
| 1176 | static long do_vmsplice(struct file *file, const struct iovec __user *iov, |
| 1177 | unsigned long nr_segs, unsigned int flags) |
| 1178 | { |
| 1179 | struct pipe_inode_info *pipe = file->f_dentry->d_inode->i_pipe; |
| 1180 | struct page *pages[PIPE_BUFFERS]; |
| 1181 | struct partial_page partial[PIPE_BUFFERS]; |
| 1182 | struct splice_pipe_desc spd = { |
| 1183 | .pages = pages, |
| 1184 | .partial = partial, |
| 1185 | .flags = flags, |
| 1186 | .ops = &user_page_pipe_buf_ops, |
| 1187 | }; |
| 1188 | |
| 1189 | if (unlikely(!pipe)) |
| 1190 | return -EBADF; |
| 1191 | if (unlikely(nr_segs > UIO_MAXIOV)) |
| 1192 | return -EINVAL; |
| 1193 | else if (unlikely(!nr_segs)) |
| 1194 | return 0; |
| 1195 | |
| 1196 | spd.nr_pages = get_iovec_page_array(iov, nr_segs, pages, partial); |
| 1197 | if (spd.nr_pages <= 0) |
| 1198 | return spd.nr_pages; |
| 1199 | |
Jens Axboe | 00522fb | 2006-04-26 14:39:29 +0200 | [diff] [blame^] | 1200 | return splice_to_pipe(pipe, &spd); |
Jens Axboe | 912d35f | 2006-04-26 10:59:21 +0200 | [diff] [blame] | 1201 | } |
| 1202 | |
| 1203 | asmlinkage long sys_vmsplice(int fd, const struct iovec __user *iov, |
| 1204 | unsigned long nr_segs, unsigned int flags) |
| 1205 | { |
| 1206 | struct file *file; |
| 1207 | long error; |
| 1208 | int fput; |
| 1209 | |
| 1210 | error = -EBADF; |
| 1211 | file = fget_light(fd, &fput); |
| 1212 | if (file) { |
| 1213 | if (file->f_mode & FMODE_WRITE) |
| 1214 | error = do_vmsplice(file, iov, nr_segs, flags); |
| 1215 | |
| 1216 | fput_light(file, fput); |
| 1217 | } |
| 1218 | |
| 1219 | return error; |
| 1220 | } |
| 1221 | |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1222 | asmlinkage long sys_splice(int fd_in, loff_t __user *off_in, |
| 1223 | int fd_out, loff_t __user *off_out, |
| 1224 | size_t len, unsigned int flags) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1225 | { |
| 1226 | long error; |
| 1227 | struct file *in, *out; |
| 1228 | int fput_in, fput_out; |
| 1229 | |
| 1230 | if (unlikely(!len)) |
| 1231 | return 0; |
| 1232 | |
| 1233 | error = -EBADF; |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1234 | in = fget_light(fd_in, &fput_in); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1235 | if (in) { |
| 1236 | if (in->f_mode & FMODE_READ) { |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1237 | out = fget_light(fd_out, &fput_out); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1238 | if (out) { |
| 1239 | if (out->f_mode & FMODE_WRITE) |
Ingo Molnar | 529565d | 2006-04-10 15:18:58 +0200 | [diff] [blame] | 1240 | error = do_splice(in, off_in, |
| 1241 | out, off_out, |
| 1242 | len, flags); |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 1243 | fput_light(out, fput_out); |
| 1244 | } |
| 1245 | } |
| 1246 | |
| 1247 | fput_light(in, fput_in); |
| 1248 | } |
| 1249 | |
| 1250 | return error; |
| 1251 | } |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1252 | |
| 1253 | /* |
| 1254 | * Link contents of ipipe to opipe. |
| 1255 | */ |
| 1256 | static int link_pipe(struct pipe_inode_info *ipipe, |
| 1257 | struct pipe_inode_info *opipe, |
| 1258 | size_t len, unsigned int flags) |
| 1259 | { |
| 1260 | struct pipe_buffer *ibuf, *obuf; |
Jens Axboe | 2a27250 | 2006-04-19 15:56:40 +0200 | [diff] [blame] | 1261 | int ret, do_wakeup, i, ipipe_first; |
| 1262 | |
| 1263 | ret = do_wakeup = ipipe_first = 0; |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1264 | |
| 1265 | /* |
| 1266 | * Potential ABBA deadlock, work around it by ordering lock |
| 1267 | * grabbing by inode address. Otherwise two different processes |
| 1268 | * could deadlock (one doing tee from A -> B, the other from B -> A). |
| 1269 | */ |
| 1270 | if (ipipe->inode < opipe->inode) { |
Jens Axboe | 2a27250 | 2006-04-19 15:56:40 +0200 | [diff] [blame] | 1271 | ipipe_first = 1; |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1272 | mutex_lock(&ipipe->inode->i_mutex); |
| 1273 | mutex_lock(&opipe->inode->i_mutex); |
| 1274 | } else { |
| 1275 | mutex_lock(&opipe->inode->i_mutex); |
| 1276 | mutex_lock(&ipipe->inode->i_mutex); |
| 1277 | } |
| 1278 | |
| 1279 | for (i = 0;; i++) { |
| 1280 | if (!opipe->readers) { |
| 1281 | send_sig(SIGPIPE, current, 0); |
| 1282 | if (!ret) |
| 1283 | ret = -EPIPE; |
| 1284 | break; |
| 1285 | } |
| 1286 | if (ipipe->nrbufs - i) { |
| 1287 | ibuf = ipipe->bufs + ((ipipe->curbuf + i) & (PIPE_BUFFERS - 1)); |
| 1288 | |
| 1289 | /* |
| 1290 | * If we have room, fill this buffer |
| 1291 | */ |
| 1292 | if (opipe->nrbufs < PIPE_BUFFERS) { |
| 1293 | int nbuf = (opipe->curbuf + opipe->nrbufs) & (PIPE_BUFFERS - 1); |
| 1294 | |
| 1295 | /* |
| 1296 | * Get a reference to this pipe buffer, |
| 1297 | * so we can copy the contents over. |
| 1298 | */ |
| 1299 | ibuf->ops->get(ipipe, ibuf); |
| 1300 | |
| 1301 | obuf = opipe->bufs + nbuf; |
| 1302 | *obuf = *ibuf; |
| 1303 | |
| 1304 | if (obuf->len > len) |
| 1305 | obuf->len = len; |
| 1306 | |
| 1307 | opipe->nrbufs++; |
| 1308 | do_wakeup = 1; |
| 1309 | ret += obuf->len; |
| 1310 | len -= obuf->len; |
| 1311 | |
| 1312 | if (!len) |
| 1313 | break; |
| 1314 | if (opipe->nrbufs < PIPE_BUFFERS) |
| 1315 | continue; |
| 1316 | } |
| 1317 | |
| 1318 | /* |
| 1319 | * We have input available, but no output room. |
Jens Axboe | 2a27250 | 2006-04-19 15:56:40 +0200 | [diff] [blame] | 1320 | * If we already copied data, return that. If we |
| 1321 | * need to drop the opipe lock, it must be ordered |
| 1322 | * last to avoid deadlocks. |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1323 | */ |
Jens Axboe | 2a27250 | 2006-04-19 15:56:40 +0200 | [diff] [blame] | 1324 | if ((flags & SPLICE_F_NONBLOCK) || !ipipe_first) { |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1325 | if (!ret) |
| 1326 | ret = -EAGAIN; |
| 1327 | break; |
| 1328 | } |
| 1329 | if (signal_pending(current)) { |
| 1330 | if (!ret) |
| 1331 | ret = -ERESTARTSYS; |
| 1332 | break; |
| 1333 | } |
| 1334 | if (do_wakeup) { |
| 1335 | smp_mb(); |
| 1336 | if (waitqueue_active(&opipe->wait)) |
| 1337 | wake_up_interruptible(&opipe->wait); |
| 1338 | kill_fasync(&opipe->fasync_readers, SIGIO, POLL_IN); |
| 1339 | do_wakeup = 0; |
| 1340 | } |
| 1341 | |
| 1342 | opipe->waiting_writers++; |
| 1343 | pipe_wait(opipe); |
| 1344 | opipe->waiting_writers--; |
| 1345 | continue; |
| 1346 | } |
| 1347 | |
| 1348 | /* |
| 1349 | * No input buffers, do the usual checks for available |
| 1350 | * writers and blocking and wait if necessary |
| 1351 | */ |
| 1352 | if (!ipipe->writers) |
| 1353 | break; |
| 1354 | if (!ipipe->waiting_writers) { |
| 1355 | if (ret) |
| 1356 | break; |
| 1357 | } |
Jens Axboe | 2a27250 | 2006-04-19 15:56:40 +0200 | [diff] [blame] | 1358 | /* |
| 1359 | * pipe_wait() drops the ipipe mutex. To avoid deadlocks |
| 1360 | * with another process, we can only safely do that if |
| 1361 | * the ipipe lock is ordered last. |
| 1362 | */ |
| 1363 | if ((flags & SPLICE_F_NONBLOCK) || ipipe_first) { |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 1364 | if (!ret) |
| 1365 | ret = -EAGAIN; |
| 1366 | break; |
| 1367 | } |
| 1368 | if (signal_pending(current)) { |
| 1369 | if (!ret) |
| 1370 | ret = -ERESTARTSYS; |
| 1371 | break; |
| 1372 | } |
| 1373 | |
| 1374 | if (waitqueue_active(&ipipe->wait)) |
| 1375 | wake_up_interruptible_sync(&ipipe->wait); |
| 1376 | kill_fasync(&ipipe->fasync_writers, SIGIO, POLL_OUT); |
| 1377 | |
| 1378 | pipe_wait(ipipe); |
| 1379 | } |
| 1380 | |
| 1381 | mutex_unlock(&ipipe->inode->i_mutex); |
| 1382 | mutex_unlock(&opipe->inode->i_mutex); |
| 1383 | |
| 1384 | if (do_wakeup) { |
| 1385 | smp_mb(); |
| 1386 | if (waitqueue_active(&opipe->wait)) |
| 1387 | wake_up_interruptible(&opipe->wait); |
| 1388 | kill_fasync(&opipe->fasync_readers, SIGIO, POLL_IN); |
| 1389 | } |
| 1390 | |
| 1391 | return ret; |
| 1392 | } |
| 1393 | |
| 1394 | /* |
| 1395 | * This is a tee(1) implementation that works on pipes. It doesn't copy |
| 1396 | * any data, it simply references the 'in' pages on the 'out' pipe. |
| 1397 | * The 'flags' used are the SPLICE_F_* variants, currently the only |
| 1398 | * applicable one is SPLICE_F_NONBLOCK. |
| 1399 | */ |
| 1400 | static long do_tee(struct file *in, struct file *out, size_t len, |
| 1401 | unsigned int flags) |
| 1402 | { |
| 1403 | struct pipe_inode_info *ipipe = in->f_dentry->d_inode->i_pipe; |
| 1404 | struct pipe_inode_info *opipe = out->f_dentry->d_inode->i_pipe; |
| 1405 | |
| 1406 | /* |
| 1407 | * Link ipipe to the two output pipes, consuming as we go along. |
| 1408 | */ |
| 1409 | if (ipipe && opipe) |
| 1410 | return link_pipe(ipipe, opipe, len, flags); |
| 1411 | |
| 1412 | return -EINVAL; |
| 1413 | } |
| 1414 | |
| 1415 | asmlinkage long sys_tee(int fdin, int fdout, size_t len, unsigned int flags) |
| 1416 | { |
| 1417 | struct file *in; |
| 1418 | int error, fput_in; |
| 1419 | |
| 1420 | if (unlikely(!len)) |
| 1421 | return 0; |
| 1422 | |
| 1423 | error = -EBADF; |
| 1424 | in = fget_light(fdin, &fput_in); |
| 1425 | if (in) { |
| 1426 | if (in->f_mode & FMODE_READ) { |
| 1427 | int fput_out; |
| 1428 | struct file *out = fget_light(fdout, &fput_out); |
| 1429 | |
| 1430 | if (out) { |
| 1431 | if (out->f_mode & FMODE_WRITE) |
| 1432 | error = do_tee(in, out, len, flags); |
| 1433 | fput_light(out, fput_out); |
| 1434 | } |
| 1435 | } |
| 1436 | fput_light(in, fput_in); |
| 1437 | } |
| 1438 | |
| 1439 | return error; |
| 1440 | } |