15274f052SJens Axboe /* 25274f052SJens Axboe * "splice": joining two ropes together by interweaving their strands. 35274f052SJens Axboe * 45274f052SJens Axboe * This is the "extended pipe" functionality, where a pipe is used as 55274f052SJens Axboe * an arbitrary in-memory buffer. Think of a pipe as a small kernel 65274f052SJens Axboe * buffer that you can use to transfer data from one end to the other. 75274f052SJens Axboe * 85274f052SJens Axboe * The traditional unix read/write is extended with a "splice()" operation 95274f052SJens Axboe * that transfers data buffers to or from a pipe buffer. 105274f052SJens Axboe * 115274f052SJens Axboe * Named by Larry McVoy, original implementation from Linus, extended by 12c2058e06SJens Axboe * Jens to support splicing to files, network, direct splicing, etc and 13c2058e06SJens Axboe * fixing lots of bugs. 145274f052SJens Axboe * 150fe23479SJens Axboe * Copyright (C) 2005-2006 Jens Axboe <axboe@kernel.dk> 16c2058e06SJens Axboe * Copyright (C) 2005-2006 Linus Torvalds <torvalds@osdl.org> 17c2058e06SJens Axboe * Copyright (C) 2006 Ingo Molnar <mingo@elte.hu> 185274f052SJens Axboe * 195274f052SJens Axboe */ 205274f052SJens Axboe #include <linux/fs.h> 215274f052SJens Axboe #include <linux/file.h> 225274f052SJens Axboe #include <linux/pagemap.h> 23d6b29d7cSJens Axboe #include <linux/splice.h> 245274f052SJens Axboe #include <linux/mm_inline.h> 255abc97aaSJens Axboe #include <linux/swap.h> 264f6f0bd2SJens Axboe #include <linux/writeback.h> 274f6f0bd2SJens Axboe #include <linux/buffer_head.h> 28a0f06780SJeff Garzik #include <linux/module.h> 294f6f0bd2SJens Axboe #include <linux/syscalls.h> 30912d35f8SJens Axboe #include <linux/uio.h> 315274f052SJens Axboe 3283f9135bSJens Axboe /* 3383f9135bSJens Axboe * Attempt to steal a page from a pipe buffer. This should perhaps go into 3483f9135bSJens Axboe * a vm helper function, it's already simplified quite a bit by the 3583f9135bSJens Axboe * addition of remove_mapping(). If success is returned, the caller may 3683f9135bSJens Axboe * attempt to reuse this page for another destination. 3783f9135bSJens Axboe */ 3876ad4d11SJens Axboe static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe, 395abc97aaSJens Axboe struct pipe_buffer *buf) 405abc97aaSJens Axboe { 415abc97aaSJens Axboe struct page *page = buf->page; 429e94cd4fSJens Axboe struct address_space *mapping; 435abc97aaSJens Axboe 449e0267c2SJens Axboe lock_page(page); 459e0267c2SJens Axboe 469e94cd4fSJens Axboe mapping = page_mapping(page); 479e94cd4fSJens Axboe if (mapping) { 485abc97aaSJens Axboe WARN_ON(!PageUptodate(page)); 495abc97aaSJens Axboe 50ad8d6f0aSJens Axboe /* 519e94cd4fSJens Axboe * At least for ext2 with nobh option, we need to wait on 529e94cd4fSJens Axboe * writeback completing on this page, since we'll remove it 539e94cd4fSJens Axboe * from the pagecache. Otherwise truncate wont wait on the 549e94cd4fSJens Axboe * page, allowing the disk blocks to be reused by someone else 559e94cd4fSJens Axboe * before we actually wrote our data to them. fs corruption 569e94cd4fSJens Axboe * ensues. 57ad8d6f0aSJens Axboe */ 58ad8d6f0aSJens Axboe wait_on_page_writeback(page); 59ad8d6f0aSJens Axboe 604f6f0bd2SJens Axboe if (PagePrivate(page)) 612ae88149SNick Piggin try_to_release_page(page, GFP_KERNEL); 624f6f0bd2SJens Axboe 639e94cd4fSJens Axboe /* 649e94cd4fSJens Axboe * If we succeeded in removing the mapping, set LRU flag 659e94cd4fSJens Axboe * and return good. 669e94cd4fSJens Axboe */ 679e94cd4fSJens Axboe if (remove_mapping(mapping, page)) { 681432873aSJens Axboe buf->flags |= PIPE_BUF_FLAG_LRU; 695abc97aaSJens Axboe return 0; 705abc97aaSJens Axboe } 719e94cd4fSJens Axboe } 729e94cd4fSJens Axboe 739e94cd4fSJens Axboe /* 749e94cd4fSJens Axboe * Raced with truncate or failed to remove page from current 759e94cd4fSJens Axboe * address space, unlock and return failure. 769e94cd4fSJens Axboe */ 779e94cd4fSJens Axboe unlock_page(page); 789e94cd4fSJens Axboe return 1; 799e94cd4fSJens Axboe } 805abc97aaSJens Axboe 8176ad4d11SJens Axboe static void page_cache_pipe_buf_release(struct pipe_inode_info *pipe, 825274f052SJens Axboe struct pipe_buffer *buf) 835274f052SJens Axboe { 845274f052SJens Axboe page_cache_release(buf->page); 851432873aSJens Axboe buf->flags &= ~PIPE_BUF_FLAG_LRU; 865274f052SJens Axboe } 875274f052SJens Axboe 8876ad4d11SJens Axboe static int page_cache_pipe_buf_pin(struct pipe_inode_info *pipe, 895274f052SJens Axboe struct pipe_buffer *buf) 905274f052SJens Axboe { 915274f052SJens Axboe struct page *page = buf->page; 9249d0b21bSJens Axboe int err; 935274f052SJens Axboe 945274f052SJens Axboe if (!PageUptodate(page)) { 9549d0b21bSJens Axboe lock_page(page); 965274f052SJens Axboe 9749d0b21bSJens Axboe /* 9849d0b21bSJens Axboe * Page got truncated/unhashed. This will cause a 0-byte 9973d62d83SIngo Molnar * splice, if this is the first page. 10049d0b21bSJens Axboe */ 1015274f052SJens Axboe if (!page->mapping) { 10249d0b21bSJens Axboe err = -ENODATA; 10349d0b21bSJens Axboe goto error; 1045274f052SJens Axboe } 1055274f052SJens Axboe 10649d0b21bSJens Axboe /* 10773d62d83SIngo Molnar * Uh oh, read-error from disk. 10849d0b21bSJens Axboe */ 10949d0b21bSJens Axboe if (!PageUptodate(page)) { 11049d0b21bSJens Axboe err = -EIO; 11149d0b21bSJens Axboe goto error; 11249d0b21bSJens Axboe } 11349d0b21bSJens Axboe 11449d0b21bSJens Axboe /* 115f84d7519SJens Axboe * Page is ok afterall, we are done. 11649d0b21bSJens Axboe */ 11749d0b21bSJens Axboe unlock_page(page); 11849d0b21bSJens Axboe } 11949d0b21bSJens Axboe 120f84d7519SJens Axboe return 0; 12149d0b21bSJens Axboe error: 12249d0b21bSJens Axboe unlock_page(page); 123f84d7519SJens Axboe return err; 12470524490SJens Axboe } 12570524490SJens Axboe 126d4c3cca9SEric Dumazet static const struct pipe_buf_operations page_cache_pipe_buf_ops = { 1275274f052SJens Axboe .can_merge = 0, 128f84d7519SJens Axboe .map = generic_pipe_buf_map, 129f84d7519SJens Axboe .unmap = generic_pipe_buf_unmap, 130f84d7519SJens Axboe .pin = page_cache_pipe_buf_pin, 1315274f052SJens Axboe .release = page_cache_pipe_buf_release, 1325abc97aaSJens Axboe .steal = page_cache_pipe_buf_steal, 133f84d7519SJens Axboe .get = generic_pipe_buf_get, 1345274f052SJens Axboe }; 1355274f052SJens Axboe 136912d35f8SJens Axboe static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe, 137912d35f8SJens Axboe struct pipe_buffer *buf) 138912d35f8SJens Axboe { 1397afa6fd0SJens Axboe if (!(buf->flags & PIPE_BUF_FLAG_GIFT)) 140912d35f8SJens Axboe return 1; 1417afa6fd0SJens Axboe 1421432873aSJens Axboe buf->flags |= PIPE_BUF_FLAG_LRU; 143330ab716SJens Axboe return generic_pipe_buf_steal(pipe, buf); 144912d35f8SJens Axboe } 145912d35f8SJens Axboe 146d4c3cca9SEric Dumazet static const struct pipe_buf_operations user_page_pipe_buf_ops = { 147912d35f8SJens Axboe .can_merge = 0, 148f84d7519SJens Axboe .map = generic_pipe_buf_map, 149f84d7519SJens Axboe .unmap = generic_pipe_buf_unmap, 150f84d7519SJens Axboe .pin = generic_pipe_buf_pin, 151912d35f8SJens Axboe .release = page_cache_pipe_buf_release, 152912d35f8SJens Axboe .steal = user_page_pipe_buf_steal, 153f84d7519SJens Axboe .get = generic_pipe_buf_get, 154912d35f8SJens Axboe }; 155912d35f8SJens Axboe 15683f9135bSJens Axboe /* 157d6b29d7cSJens Axboe * Pipe output worker. This fills a pipe with the information contained 158d6b29d7cSJens Axboe * from splice_pipe_desc(). 15983f9135bSJens Axboe */ 160d6b29d7cSJens Axboe ssize_t splice_to_pipe(struct pipe_inode_info *pipe, 161912d35f8SJens Axboe struct splice_pipe_desc *spd) 1625274f052SJens Axboe { 16300de00bdSJens Axboe unsigned int spd_pages = spd->nr_pages; 164912d35f8SJens Axboe int ret, do_wakeup, page_nr; 1655274f052SJens Axboe 1665274f052SJens Axboe ret = 0; 1675274f052SJens Axboe do_wakeup = 0; 168912d35f8SJens Axboe page_nr = 0; 1695274f052SJens Axboe 1703a326a2cSIngo Molnar if (pipe->inode) 1713a326a2cSIngo Molnar mutex_lock(&pipe->inode->i_mutex); 1725274f052SJens Axboe 1735274f052SJens Axboe for (;;) { 1743a326a2cSIngo Molnar if (!pipe->readers) { 1755274f052SJens Axboe send_sig(SIGPIPE, current, 0); 1765274f052SJens Axboe if (!ret) 1775274f052SJens Axboe ret = -EPIPE; 1785274f052SJens Axboe break; 1795274f052SJens Axboe } 1805274f052SJens Axboe 1816f767b04SJens Axboe if (pipe->nrbufs < PIPE_BUFFERS) { 1826f767b04SJens Axboe int newbuf = (pipe->curbuf + pipe->nrbufs) & (PIPE_BUFFERS - 1); 1833a326a2cSIngo Molnar struct pipe_buffer *buf = pipe->bufs + newbuf; 1845274f052SJens Axboe 185912d35f8SJens Axboe buf->page = spd->pages[page_nr]; 186912d35f8SJens Axboe buf->offset = spd->partial[page_nr].offset; 187912d35f8SJens Axboe buf->len = spd->partial[page_nr].len; 188912d35f8SJens Axboe buf->ops = spd->ops; 1897afa6fd0SJens Axboe if (spd->flags & SPLICE_F_GIFT) 1907afa6fd0SJens Axboe buf->flags |= PIPE_BUF_FLAG_GIFT; 1917afa6fd0SJens Axboe 1926f767b04SJens Axboe pipe->nrbufs++; 193912d35f8SJens Axboe page_nr++; 194912d35f8SJens Axboe ret += buf->len; 195912d35f8SJens Axboe 1966f767b04SJens Axboe if (pipe->inode) 1975274f052SJens Axboe do_wakeup = 1; 1985274f052SJens Axboe 199912d35f8SJens Axboe if (!--spd->nr_pages) 2005274f052SJens Axboe break; 2016f767b04SJens Axboe if (pipe->nrbufs < PIPE_BUFFERS) 2025274f052SJens Axboe continue; 2035274f052SJens Axboe 2045274f052SJens Axboe break; 2055274f052SJens Axboe } 2065274f052SJens Axboe 207912d35f8SJens Axboe if (spd->flags & SPLICE_F_NONBLOCK) { 20829e35094SLinus Torvalds if (!ret) 20929e35094SLinus Torvalds ret = -EAGAIN; 21029e35094SLinus Torvalds break; 21129e35094SLinus Torvalds } 21229e35094SLinus Torvalds 2135274f052SJens Axboe if (signal_pending(current)) { 2145274f052SJens Axboe if (!ret) 2155274f052SJens Axboe ret = -ERESTARTSYS; 2165274f052SJens Axboe break; 2175274f052SJens Axboe } 2185274f052SJens Axboe 2195274f052SJens Axboe if (do_wakeup) { 220c0bd1f65SJens Axboe smp_mb(); 2213a326a2cSIngo Molnar if (waitqueue_active(&pipe->wait)) 2223a326a2cSIngo Molnar wake_up_interruptible_sync(&pipe->wait); 2233a326a2cSIngo Molnar kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); 2245274f052SJens Axboe do_wakeup = 0; 2255274f052SJens Axboe } 2265274f052SJens Axboe 2273a326a2cSIngo Molnar pipe->waiting_writers++; 2283a326a2cSIngo Molnar pipe_wait(pipe); 2293a326a2cSIngo Molnar pipe->waiting_writers--; 2305274f052SJens Axboe } 2315274f052SJens Axboe 23202676e5aSJens Axboe if (pipe->inode) { 2333a326a2cSIngo Molnar mutex_unlock(&pipe->inode->i_mutex); 2345274f052SJens Axboe 2355274f052SJens Axboe if (do_wakeup) { 236c0bd1f65SJens Axboe smp_mb(); 2373a326a2cSIngo Molnar if (waitqueue_active(&pipe->wait)) 2383a326a2cSIngo Molnar wake_up_interruptible(&pipe->wait); 2393a326a2cSIngo Molnar kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); 2405274f052SJens Axboe } 24102676e5aSJens Axboe } 2425274f052SJens Axboe 24300de00bdSJens Axboe while (page_nr < spd_pages) 244912d35f8SJens Axboe page_cache_release(spd->pages[page_nr++]); 2455274f052SJens Axboe 2465274f052SJens Axboe return ret; 2475274f052SJens Axboe } 2485274f052SJens Axboe 2493a326a2cSIngo Molnar static int 250cbb7e577SJens Axboe __generic_file_splice_read(struct file *in, loff_t *ppos, 251cbb7e577SJens Axboe struct pipe_inode_info *pipe, size_t len, 252cbb7e577SJens Axboe unsigned int flags) 2535274f052SJens Axboe { 2545274f052SJens Axboe struct address_space *mapping = in->f_mapping; 255912d35f8SJens Axboe unsigned int loff, nr_pages; 25616c523ddSJens Axboe struct page *pages[PIPE_BUFFERS]; 257912d35f8SJens Axboe struct partial_page partial[PIPE_BUFFERS]; 2585274f052SJens Axboe struct page *page; 25991ad66efSJens Axboe pgoff_t index, end_index; 26091ad66efSJens Axboe loff_t isize; 261eb20796bSJens Axboe int error, page_nr; 262912d35f8SJens Axboe struct splice_pipe_desc spd = { 263912d35f8SJens Axboe .pages = pages, 264912d35f8SJens Axboe .partial = partial, 265912d35f8SJens Axboe .flags = flags, 266912d35f8SJens Axboe .ops = &page_cache_pipe_buf_ops, 267912d35f8SJens Axboe }; 2685274f052SJens Axboe 269cbb7e577SJens Axboe index = *ppos >> PAGE_CACHE_SHIFT; 270912d35f8SJens Axboe loff = *ppos & ~PAGE_CACHE_MASK; 271912d35f8SJens Axboe nr_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; 2725274f052SJens Axboe 2735274f052SJens Axboe if (nr_pages > PIPE_BUFFERS) 2745274f052SJens Axboe nr_pages = PIPE_BUFFERS; 2755274f052SJens Axboe 2765274f052SJens Axboe /* 27786aa5ac5SJens Axboe * Don't try to 2nd guess the read-ahead logic, call into 27886aa5ac5SJens Axboe * page_cache_readahead() like the page cache reads would do. 2795274f052SJens Axboe */ 280eb645a24SJens Axboe page_cache_readahead(mapping, &in->f_ra, in, index, nr_pages); 2815274f052SJens Axboe 2825274f052SJens Axboe /* 28373d62d83SIngo Molnar * Now fill in the holes: 2845274f052SJens Axboe */ 2857480a904SJens Axboe error = 0; 28682aa5d61SJens Axboe 28782aa5d61SJens Axboe /* 288eb20796bSJens Axboe * Lookup the (hopefully) full range of pages we need. 28982aa5d61SJens Axboe */ 290eb20796bSJens Axboe spd.nr_pages = find_get_pages_contig(mapping, index, nr_pages, pages); 291eb20796bSJens Axboe 2925274f052SJens Axboe /* 293eb20796bSJens Axboe * If find_get_pages_contig() returned fewer pages than we needed, 294eb20796bSJens Axboe * allocate the rest. 295eb20796bSJens Axboe */ 296eb20796bSJens Axboe index += spd.nr_pages; 297eb20796bSJens Axboe while (spd.nr_pages < nr_pages) { 298eb20796bSJens Axboe /* 299eb20796bSJens Axboe * Page could be there, find_get_pages_contig() breaks on 300eb20796bSJens Axboe * the first hole. 3015274f052SJens Axboe */ 3027480a904SJens Axboe page = find_get_page(mapping, index); 3037480a904SJens Axboe if (!page) { 3047480a904SJens Axboe /* 305e27dedd8SJens Axboe * Make sure the read-ahead engine is notified 306e27dedd8SJens Axboe * about this failure. 307e27dedd8SJens Axboe */ 308e27dedd8SJens Axboe handle_ra_miss(mapping, &in->f_ra, index); 309e27dedd8SJens Axboe 310e27dedd8SJens Axboe /* 311eb20796bSJens Axboe * page didn't exist, allocate one. 3127480a904SJens Axboe */ 3137480a904SJens Axboe page = page_cache_alloc_cold(mapping); 3145274f052SJens Axboe if (!page) 3155274f052SJens Axboe break; 3165274f052SJens Axboe 3177480a904SJens Axboe error = add_to_page_cache_lru(page, mapping, index, 3182ae88149SNick Piggin GFP_KERNEL); 3195274f052SJens Axboe if (unlikely(error)) { 3205274f052SJens Axboe page_cache_release(page); 321a0548871SJens Axboe if (error == -EEXIST) 322a0548871SJens Axboe continue; 3235274f052SJens Axboe break; 3245274f052SJens Axboe } 325eb20796bSJens Axboe /* 326eb20796bSJens Axboe * add_to_page_cache() locks the page, unlock it 327eb20796bSJens Axboe * to avoid convoluting the logic below even more. 328eb20796bSJens Axboe */ 329eb20796bSJens Axboe unlock_page(page); 3305274f052SJens Axboe } 3317480a904SJens Axboe 332eb20796bSJens Axboe pages[spd.nr_pages++] = page; 333eb20796bSJens Axboe index++; 334eb20796bSJens Axboe } 335eb20796bSJens Axboe 336eb20796bSJens Axboe /* 337eb20796bSJens Axboe * Now loop over the map and see if we need to start IO on any 338eb20796bSJens Axboe * pages, fill in the partial map, etc. 339eb20796bSJens Axboe */ 340eb20796bSJens Axboe index = *ppos >> PAGE_CACHE_SHIFT; 341eb20796bSJens Axboe nr_pages = spd.nr_pages; 342eb20796bSJens Axboe spd.nr_pages = 0; 343eb20796bSJens Axboe for (page_nr = 0; page_nr < nr_pages; page_nr++) { 344eb20796bSJens Axboe unsigned int this_len; 345eb20796bSJens Axboe 346eb20796bSJens Axboe if (!len) 347eb20796bSJens Axboe break; 348eb20796bSJens Axboe 349eb20796bSJens Axboe /* 350eb20796bSJens Axboe * this_len is the max we'll use from this page 351eb20796bSJens Axboe */ 352eb20796bSJens Axboe this_len = min_t(unsigned long, len, PAGE_CACHE_SIZE - loff); 353eb20796bSJens Axboe page = pages[page_nr]; 354eb20796bSJens Axboe 3557480a904SJens Axboe /* 3567480a904SJens Axboe * If the page isn't uptodate, we may need to start io on it 3577480a904SJens Axboe */ 3587480a904SJens Axboe if (!PageUptodate(page)) { 359c4f895cbSJens Axboe /* 360c4f895cbSJens Axboe * If in nonblock mode then dont block on waiting 361c4f895cbSJens Axboe * for an in-flight io page 362c4f895cbSJens Axboe */ 3639ae9d68cSFengguang Wu if (flags & SPLICE_F_NONBLOCK) { 3649ae9d68cSFengguang Wu if (TestSetPageLocked(page)) 365c4f895cbSJens Axboe break; 3669ae9d68cSFengguang Wu } else 3677480a904SJens Axboe lock_page(page); 3687480a904SJens Axboe 3697480a904SJens Axboe /* 3707480a904SJens Axboe * page was truncated, stop here. if this isn't the 3717480a904SJens Axboe * first page, we'll just complete what we already 3727480a904SJens Axboe * added 3737480a904SJens Axboe */ 3747480a904SJens Axboe if (!page->mapping) { 3757480a904SJens Axboe unlock_page(page); 3767480a904SJens Axboe break; 3777480a904SJens Axboe } 3787480a904SJens Axboe /* 3797480a904SJens Axboe * page was already under io and is now done, great 3807480a904SJens Axboe */ 3817480a904SJens Axboe if (PageUptodate(page)) { 3827480a904SJens Axboe unlock_page(page); 3837480a904SJens Axboe goto fill_it; 3847480a904SJens Axboe } 3857480a904SJens Axboe 3867480a904SJens Axboe /* 3877480a904SJens Axboe * need to read in the page 3887480a904SJens Axboe */ 3897480a904SJens Axboe error = mapping->a_ops->readpage(in, page); 3907480a904SJens Axboe if (unlikely(error)) { 391eb20796bSJens Axboe /* 392eb20796bSJens Axboe * We really should re-lookup the page here, 393eb20796bSJens Axboe * but it complicates things a lot. Instead 394eb20796bSJens Axboe * lets just do what we already stored, and 395eb20796bSJens Axboe * we'll get it the next time we are called. 396eb20796bSJens Axboe */ 3977480a904SJens Axboe if (error == AOP_TRUNCATED_PAGE) 398eb20796bSJens Axboe error = 0; 399eb20796bSJens Axboe 4007480a904SJens Axboe break; 4017480a904SJens Axboe } 402620a324bSJens Axboe } 403620a324bSJens Axboe fill_it: 40491ad66efSJens Axboe /* 405620a324bSJens Axboe * i_size must be checked after PageUptodate. 40691ad66efSJens Axboe */ 40791ad66efSJens Axboe isize = i_size_read(mapping->host); 40891ad66efSJens Axboe end_index = (isize - 1) >> PAGE_CACHE_SHIFT; 409eb20796bSJens Axboe if (unlikely(!isize || index > end_index)) 41091ad66efSJens Axboe break; 41191ad66efSJens Axboe 41291ad66efSJens Axboe /* 41391ad66efSJens Axboe * if this is the last page, see if we need to shrink 41491ad66efSJens Axboe * the length and stop 41591ad66efSJens Axboe */ 41691ad66efSJens Axboe if (end_index == index) { 417475ecadeSHugh Dickins unsigned int plen; 418475ecadeSHugh Dickins 419475ecadeSHugh Dickins /* 420475ecadeSHugh Dickins * max good bytes in this page 421475ecadeSHugh Dickins */ 422475ecadeSHugh Dickins plen = ((isize - 1) & ~PAGE_CACHE_MASK) + 1; 423475ecadeSHugh Dickins if (plen <= loff) 42491ad66efSJens Axboe break; 425475ecadeSHugh Dickins 42691ad66efSJens Axboe /* 42791ad66efSJens Axboe * force quit after adding this page 42891ad66efSJens Axboe */ 429475ecadeSHugh Dickins this_len = min(this_len, plen - loff); 430eb20796bSJens Axboe len = this_len; 43191ad66efSJens Axboe } 432620a324bSJens Axboe 433eb20796bSJens Axboe partial[page_nr].offset = loff; 434eb20796bSJens Axboe partial[page_nr].len = this_len; 43582aa5d61SJens Axboe len -= this_len; 43691ad66efSJens Axboe loff = 0; 437eb20796bSJens Axboe spd.nr_pages++; 438eb20796bSJens Axboe index++; 4395274f052SJens Axboe } 4405274f052SJens Axboe 441eb20796bSJens Axboe /* 442475ecadeSHugh Dickins * Release any pages at the end, if we quit early. 'page_nr' is how far 443eb20796bSJens Axboe * we got, 'nr_pages' is how many pages are in the map. 444eb20796bSJens Axboe */ 445eb20796bSJens Axboe while (page_nr < nr_pages) 446eb20796bSJens Axboe page_cache_release(pages[page_nr++]); 447eb20796bSJens Axboe 448912d35f8SJens Axboe if (spd.nr_pages) 44900522fb4SJens Axboe return splice_to_pipe(pipe, &spd); 45016c523ddSJens Axboe 4517480a904SJens Axboe return error; 4525274f052SJens Axboe } 4535274f052SJens Axboe 45483f9135bSJens Axboe /** 45583f9135bSJens Axboe * generic_file_splice_read - splice data from file to a pipe 45683f9135bSJens Axboe * @in: file to splice from 45783f9135bSJens Axboe * @pipe: pipe to splice to 45883f9135bSJens Axboe * @len: number of bytes to splice 45983f9135bSJens Axboe * @flags: splice modifier flags 46083f9135bSJens Axboe * 46183f9135bSJens Axboe * Will read pages from given file and fill them into a pipe. 46283f9135bSJens Axboe */ 463cbb7e577SJens Axboe ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, 464cbb7e577SJens Axboe struct pipe_inode_info *pipe, size_t len, 465cbb7e577SJens Axboe unsigned int flags) 4665274f052SJens Axboe { 4675274f052SJens Axboe ssize_t spliced; 4685274f052SJens Axboe int ret; 469d366d398SJens Axboe loff_t isize, left; 470d366d398SJens Axboe 471d366d398SJens Axboe isize = i_size_read(in->f_mapping->host); 472d366d398SJens Axboe if (unlikely(*ppos >= isize)) 473d366d398SJens Axboe return 0; 474d366d398SJens Axboe 475d366d398SJens Axboe left = isize - *ppos; 476d366d398SJens Axboe if (unlikely(left < len)) 477d366d398SJens Axboe len = left; 4785274f052SJens Axboe 4795274f052SJens Axboe ret = 0; 4805274f052SJens Axboe spliced = 0; 4815274f052SJens Axboe while (len) { 482cbb7e577SJens Axboe ret = __generic_file_splice_read(in, ppos, pipe, len, flags); 4835274f052SJens Axboe 484c4f895cbSJens Axboe if (ret < 0) 4855274f052SJens Axboe break; 486c4f895cbSJens Axboe else if (!ret) { 487c4f895cbSJens Axboe if (spliced) 488c4f895cbSJens Axboe break; 489c4f895cbSJens Axboe if (flags & SPLICE_F_NONBLOCK) { 490c4f895cbSJens Axboe ret = -EAGAIN; 491c4f895cbSJens Axboe break; 492c4f895cbSJens Axboe } 493c4f895cbSJens Axboe } 4945274f052SJens Axboe 495cbb7e577SJens Axboe *ppos += ret; 4965274f052SJens Axboe len -= ret; 4975274f052SJens Axboe spliced += ret; 4985274f052SJens Axboe } 4995274f052SJens Axboe 5005274f052SJens Axboe if (spliced) 5015274f052SJens Axboe return spliced; 5025274f052SJens Axboe 5035274f052SJens Axboe return ret; 5045274f052SJens Axboe } 5055274f052SJens Axboe 506059a8f37SJens Axboe EXPORT_SYMBOL(generic_file_splice_read); 507059a8f37SJens Axboe 5085274f052SJens Axboe /* 5094f6f0bd2SJens Axboe * Send 'sd->len' bytes to socket from 'sd->file' at position 'sd->pos' 510016b661eSJens Axboe * using sendpage(). Return the number of bytes sent. 5115274f052SJens Axboe */ 51276ad4d11SJens Axboe static int pipe_to_sendpage(struct pipe_inode_info *pipe, 5135274f052SJens Axboe struct pipe_buffer *buf, struct splice_desc *sd) 5145274f052SJens Axboe { 5156a14b90bSJens Axboe struct file *file = sd->u.file; 5165274f052SJens Axboe loff_t pos = sd->pos; 517f84d7519SJens Axboe int ret, more; 5185274f052SJens Axboe 51976ad4d11SJens Axboe ret = buf->ops->pin(pipe, buf); 520f84d7519SJens Axboe if (!ret) { 521b2b39fa4SJens Axboe more = (sd->flags & SPLICE_F_MORE) || sd->len < sd->total_len; 5225274f052SJens Axboe 523f84d7519SJens Axboe ret = file->f_op->sendpage(file, buf->page, buf->offset, 524f84d7519SJens Axboe sd->len, &pos, more); 525f84d7519SJens Axboe } 5265274f052SJens Axboe 527016b661eSJens Axboe return ret; 5285274f052SJens Axboe } 5295274f052SJens Axboe 5305274f052SJens Axboe /* 5315274f052SJens Axboe * This is a little more tricky than the file -> pipe splicing. There are 5325274f052SJens Axboe * basically three cases: 5335274f052SJens Axboe * 5345274f052SJens Axboe * - Destination page already exists in the address space and there 5355274f052SJens Axboe * are users of it. For that case we have no other option that 5365274f052SJens Axboe * copying the data. Tough luck. 5375274f052SJens Axboe * - Destination page already exists in the address space, but there 5385274f052SJens Axboe * are no users of it. Make sure it's uptodate, then drop it. Fall 5395274f052SJens Axboe * through to last case. 5405274f052SJens Axboe * - Destination page does not exist, we can add the pipe page to 5415274f052SJens Axboe * the page cache and avoid the copy. 5425274f052SJens Axboe * 54383f9135bSJens Axboe * If asked to move pages to the output file (SPLICE_F_MOVE is set in 54483f9135bSJens Axboe * sd->flags), we attempt to migrate pages from the pipe to the output 54583f9135bSJens Axboe * file address space page cache. This is possible if no one else has 54683f9135bSJens Axboe * the pipe page referenced outside of the pipe and page cache. If 54783f9135bSJens Axboe * SPLICE_F_MOVE isn't set, or we cannot move the page, we simply create 54883f9135bSJens Axboe * a new page in the output file page cache and fill/dirty that. 5495274f052SJens Axboe */ 55076ad4d11SJens Axboe static int pipe_to_file(struct pipe_inode_info *pipe, struct pipe_buffer *buf, 5515274f052SJens Axboe struct splice_desc *sd) 5525274f052SJens Axboe { 5536a14b90bSJens Axboe struct file *file = sd->u.file; 5545274f052SJens Axboe struct address_space *mapping = file->f_mapping; 555016b661eSJens Axboe unsigned int offset, this_len; 5565274f052SJens Axboe struct page *page; 5575274f052SJens Axboe pgoff_t index; 5583e7ee3e7SJens Axboe int ret; 5595274f052SJens Axboe 5605274f052SJens Axboe /* 56149d0b21bSJens Axboe * make sure the data in this buffer is uptodate 5625274f052SJens Axboe */ 56376ad4d11SJens Axboe ret = buf->ops->pin(pipe, buf); 564f84d7519SJens Axboe if (unlikely(ret)) 565f84d7519SJens Axboe return ret; 5665274f052SJens Axboe 5675274f052SJens Axboe index = sd->pos >> PAGE_CACHE_SHIFT; 5685274f052SJens Axboe offset = sd->pos & ~PAGE_CACHE_MASK; 5695274f052SJens Axboe 570016b661eSJens Axboe this_len = sd->len; 571016b661eSJens Axboe if (this_len + offset > PAGE_CACHE_SIZE) 572016b661eSJens Axboe this_len = PAGE_CACHE_SIZE - offset; 573016b661eSJens Axboe 5745274f052SJens Axboe find_page: 5759e0267c2SJens Axboe page = find_lock_page(mapping, index); 5769e0267c2SJens Axboe if (!page) { 5775274f052SJens Axboe ret = -ENOMEM; 5789e0267c2SJens Axboe page = page_cache_alloc_cold(mapping); 5799e0267c2SJens Axboe if (unlikely(!page)) 580e6e80f29SJens Axboe goto out_ret; 5815274f052SJens Axboe 5825274f052SJens Axboe /* 5839e0267c2SJens Axboe * This will also lock the page 5849e0267c2SJens Axboe */ 5859e0267c2SJens Axboe ret = add_to_page_cache_lru(page, mapping, index, 5862ae88149SNick Piggin GFP_KERNEL); 5879e0267c2SJens Axboe if (unlikely(ret)) 5889e0267c2SJens Axboe goto out; 5899e0267c2SJens Axboe } 5909e0267c2SJens Axboe 591016b661eSJens Axboe ret = mapping->a_ops->prepare_write(file, page, offset, offset+this_len); 592bfc4ee39SJens Axboe if (unlikely(ret)) { 593bfc4ee39SJens Axboe loff_t isize = i_size_read(mapping->host); 594bfc4ee39SJens Axboe 595bfc4ee39SJens Axboe if (ret != AOP_TRUNCATED_PAGE) 596bfc4ee39SJens Axboe unlock_page(page); 5974f6f0bd2SJens Axboe page_cache_release(page); 598bfc4ee39SJens Axboe if (ret == AOP_TRUNCATED_PAGE) 5994f6f0bd2SJens Axboe goto find_page; 600bfc4ee39SJens Axboe 601bfc4ee39SJens Axboe /* 602bfc4ee39SJens Axboe * prepare_write() may have instantiated a few blocks 603bfc4ee39SJens Axboe * outside i_size. Trim these off again. 604bfc4ee39SJens Axboe */ 605bfc4ee39SJens Axboe if (sd->pos + this_len > isize) 606bfc4ee39SJens Axboe vmtruncate(mapping->host, isize); 607bfc4ee39SJens Axboe 608e6e80f29SJens Axboe goto out_ret; 609bfc4ee39SJens Axboe } 6105274f052SJens Axboe 6110568b409SJens Axboe if (buf->page != page) { 612f84d7519SJens Axboe /* 613f84d7519SJens Axboe * Careful, ->map() uses KM_USER0! 614f84d7519SJens Axboe */ 61576ad4d11SJens Axboe char *src = buf->ops->map(pipe, buf, 1); 616f84d7519SJens Axboe char *dst = kmap_atomic(page, KM_USER1); 6175abc97aaSJens Axboe 618016b661eSJens Axboe memcpy(dst + offset, src + buf->offset, this_len); 6195274f052SJens Axboe flush_dcache_page(page); 620f84d7519SJens Axboe kunmap_atomic(dst, KM_USER1); 62176ad4d11SJens Axboe buf->ops->unmap(pipe, buf, src); 6225abc97aaSJens Axboe } 6235274f052SJens Axboe 624016b661eSJens Axboe ret = mapping->a_ops->commit_write(file, page, offset, offset+this_len); 625d9993c37SDmitriy Monakhov if (ret) { 626d9993c37SDmitriy Monakhov if (ret == AOP_TRUNCATED_PAGE) { 627d9993c37SDmitriy Monakhov page_cache_release(page); 628d9993c37SDmitriy Monakhov goto find_page; 629d9993c37SDmitriy Monakhov } 630d9993c37SDmitriy Monakhov if (ret < 0) 631d9993c37SDmitriy Monakhov goto out; 632d9993c37SDmitriy Monakhov /* 633d9993c37SDmitriy Monakhov * Partial write has happened, so 'ret' already initialized by 634d9993c37SDmitriy Monakhov * number of bytes written, Where is nothing we have to do here. 635d9993c37SDmitriy Monakhov */ 636d9993c37SDmitriy Monakhov } else 637d9993c37SDmitriy Monakhov ret = this_len; 638016b661eSJens Axboe /* 6390568b409SJens Axboe * Return the number of bytes written and mark page as 6400568b409SJens Axboe * accessed, we are now done! 641016b661eSJens Axboe */ 642c7f21e4fSJens Axboe mark_page_accessed(page); 6430568b409SJens Axboe out: 6440568b409SJens Axboe page_cache_release(page); 6454f6f0bd2SJens Axboe unlock_page(page); 646e6e80f29SJens Axboe out_ret: 6475274f052SJens Axboe return ret; 6485274f052SJens Axboe } 6495274f052SJens Axboe 65083f9135bSJens Axboe /* 65183f9135bSJens Axboe * Pipe input worker. Most of this logic works like a regular pipe, the 65283f9135bSJens Axboe * key here is the 'actor' worker passed in that actually moves the data 65383f9135bSJens Axboe * to the wanted destination. See pipe_to_file/pipe_to_sendpage above. 65483f9135bSJens Axboe */ 655c66ab6faSJens Axboe ssize_t __splice_from_pipe(struct pipe_inode_info *pipe, struct splice_desc *sd, 656c66ab6faSJens Axboe splice_actor *actor) 6575274f052SJens Axboe { 6585274f052SJens Axboe int ret, do_wakeup, err; 6595274f052SJens Axboe 6605274f052SJens Axboe ret = 0; 6615274f052SJens Axboe do_wakeup = 0; 6625274f052SJens Axboe 6635274f052SJens Axboe for (;;) { 6646f767b04SJens Axboe if (pipe->nrbufs) { 6656f767b04SJens Axboe struct pipe_buffer *buf = pipe->bufs + pipe->curbuf; 666d4c3cca9SEric Dumazet const struct pipe_buf_operations *ops = buf->ops; 6675274f052SJens Axboe 668c66ab6faSJens Axboe sd->len = buf->len; 669c66ab6faSJens Axboe if (sd->len > sd->total_len) 670c66ab6faSJens Axboe sd->len = sd->total_len; 6715274f052SJens Axboe 672c66ab6faSJens Axboe err = actor(pipe, buf, sd); 673016b661eSJens Axboe if (err <= 0) { 6745274f052SJens Axboe if (!ret && err != -ENODATA) 6755274f052SJens Axboe ret = err; 6765274f052SJens Axboe 6775274f052SJens Axboe break; 6785274f052SJens Axboe } 6795274f052SJens Axboe 680016b661eSJens Axboe ret += err; 681016b661eSJens Axboe buf->offset += err; 682016b661eSJens Axboe buf->len -= err; 683016b661eSJens Axboe 684c66ab6faSJens Axboe sd->len -= err; 685c66ab6faSJens Axboe sd->pos += err; 686c66ab6faSJens Axboe sd->total_len -= err; 687c66ab6faSJens Axboe if (sd->len) 688016b661eSJens Axboe continue; 68973d62d83SIngo Molnar 6905274f052SJens Axboe if (!buf->len) { 6915274f052SJens Axboe buf->ops = NULL; 6923a326a2cSIngo Molnar ops->release(pipe, buf); 6936f767b04SJens Axboe pipe->curbuf = (pipe->curbuf + 1) & (PIPE_BUFFERS - 1); 6946f767b04SJens Axboe pipe->nrbufs--; 6956f767b04SJens Axboe if (pipe->inode) 6965274f052SJens Axboe do_wakeup = 1; 6975274f052SJens Axboe } 6985274f052SJens Axboe 699c66ab6faSJens Axboe if (!sd->total_len) 7005274f052SJens Axboe break; 7015274f052SJens Axboe } 7025274f052SJens Axboe 7036f767b04SJens Axboe if (pipe->nrbufs) 7045274f052SJens Axboe continue; 7053a326a2cSIngo Molnar if (!pipe->writers) 7065274f052SJens Axboe break; 7073a326a2cSIngo Molnar if (!pipe->waiting_writers) { 7085274f052SJens Axboe if (ret) 7095274f052SJens Axboe break; 7105274f052SJens Axboe } 7115274f052SJens Axboe 712c66ab6faSJens Axboe if (sd->flags & SPLICE_F_NONBLOCK) { 71329e35094SLinus Torvalds if (!ret) 71429e35094SLinus Torvalds ret = -EAGAIN; 71529e35094SLinus Torvalds break; 71629e35094SLinus Torvalds } 71729e35094SLinus Torvalds 7185274f052SJens Axboe if (signal_pending(current)) { 7195274f052SJens Axboe if (!ret) 7205274f052SJens Axboe ret = -ERESTARTSYS; 7215274f052SJens Axboe break; 7225274f052SJens Axboe } 7235274f052SJens Axboe 7245274f052SJens Axboe if (do_wakeup) { 725c0bd1f65SJens Axboe smp_mb(); 7263a326a2cSIngo Molnar if (waitqueue_active(&pipe->wait)) 7273a326a2cSIngo Molnar wake_up_interruptible_sync(&pipe->wait); 7283a326a2cSIngo Molnar kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); 7295274f052SJens Axboe do_wakeup = 0; 7305274f052SJens Axboe } 7315274f052SJens Axboe 7323a326a2cSIngo Molnar pipe_wait(pipe); 7335274f052SJens Axboe } 7345274f052SJens Axboe 7355274f052SJens Axboe if (do_wakeup) { 736c0bd1f65SJens Axboe smp_mb(); 7373a326a2cSIngo Molnar if (waitqueue_active(&pipe->wait)) 7383a326a2cSIngo Molnar wake_up_interruptible(&pipe->wait); 7393a326a2cSIngo Molnar kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); 7405274f052SJens Axboe } 7415274f052SJens Axboe 7425274f052SJens Axboe return ret; 7435274f052SJens Axboe } 74440bee44eSMark Fasheh EXPORT_SYMBOL(__splice_from_pipe); 7455274f052SJens Axboe 7466da61809SMark Fasheh ssize_t splice_from_pipe(struct pipe_inode_info *pipe, struct file *out, 7476da61809SMark Fasheh loff_t *ppos, size_t len, unsigned int flags, 7486da61809SMark Fasheh splice_actor *actor) 7496da61809SMark Fasheh { 7506da61809SMark Fasheh ssize_t ret; 7516da61809SMark Fasheh struct inode *inode = out->f_mapping->host; 752c66ab6faSJens Axboe struct splice_desc sd = { 753c66ab6faSJens Axboe .total_len = len, 754c66ab6faSJens Axboe .flags = flags, 755c66ab6faSJens Axboe .pos = *ppos, 7566a14b90bSJens Axboe .u.file = out, 757c66ab6faSJens Axboe }; 7586da61809SMark Fasheh 7596da61809SMark Fasheh /* 7606da61809SMark Fasheh * The actor worker might be calling ->prepare_write and 7616da61809SMark Fasheh * ->commit_write. Most of the time, these expect i_mutex to 7626da61809SMark Fasheh * be held. Since this may result in an ABBA deadlock with 7636da61809SMark Fasheh * pipe->inode, we have to order lock acquiry here. 7646da61809SMark Fasheh */ 7656da61809SMark Fasheh inode_double_lock(inode, pipe->inode); 766c66ab6faSJens Axboe ret = __splice_from_pipe(pipe, &sd, actor); 7676da61809SMark Fasheh inode_double_unlock(inode, pipe->inode); 7686da61809SMark Fasheh 7696da61809SMark Fasheh return ret; 7706da61809SMark Fasheh } 7716da61809SMark Fasheh 7726da61809SMark Fasheh /** 7736da61809SMark Fasheh * generic_file_splice_write_nolock - generic_file_splice_write without mutexes 7746da61809SMark Fasheh * @pipe: pipe info 7756da61809SMark Fasheh * @out: file to write to 7766da61809SMark Fasheh * @len: number of bytes to splice 7776da61809SMark Fasheh * @flags: splice modifier flags 7786da61809SMark Fasheh * 7796da61809SMark Fasheh * Will either move or copy pages (determined by @flags options) from 7806da61809SMark Fasheh * the given pipe inode to the given file. The caller is responsible 7816da61809SMark Fasheh * for acquiring i_mutex on both inodes. 7826da61809SMark Fasheh * 7836da61809SMark Fasheh */ 7846da61809SMark Fasheh ssize_t 7856da61809SMark Fasheh generic_file_splice_write_nolock(struct pipe_inode_info *pipe, struct file *out, 7866da61809SMark Fasheh loff_t *ppos, size_t len, unsigned int flags) 7876da61809SMark Fasheh { 7886da61809SMark Fasheh struct address_space *mapping = out->f_mapping; 7896da61809SMark Fasheh struct inode *inode = mapping->host; 790c66ab6faSJens Axboe struct splice_desc sd = { 791c66ab6faSJens Axboe .total_len = len, 792c66ab6faSJens Axboe .flags = flags, 793c66ab6faSJens Axboe .pos = *ppos, 7946a14b90bSJens Axboe .u.file = out, 795c66ab6faSJens Axboe }; 7966da61809SMark Fasheh ssize_t ret; 7976da61809SMark Fasheh int err; 7986da61809SMark Fasheh 7990f7fc9e4SJosef "Jeff" Sipek err = remove_suid(out->f_path.dentry); 8008c34e2d6SJens Axboe if (unlikely(err)) 8018c34e2d6SJens Axboe return err; 8028c34e2d6SJens Axboe 803c66ab6faSJens Axboe ret = __splice_from_pipe(pipe, &sd, pipe_to_file); 8046da61809SMark Fasheh if (ret > 0) { 80517ee4f49SJens Axboe unsigned long nr_pages; 80617ee4f49SJens Axboe 8076da61809SMark Fasheh *ppos += ret; 80817ee4f49SJens Axboe nr_pages = (ret + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; 8096da61809SMark Fasheh 8106da61809SMark Fasheh /* 8116da61809SMark Fasheh * If file or inode is SYNC and we actually wrote some data, 8126da61809SMark Fasheh * sync it. 8136da61809SMark Fasheh */ 8146da61809SMark Fasheh if (unlikely((out->f_flags & O_SYNC) || IS_SYNC(inode))) { 8156da61809SMark Fasheh err = generic_osync_inode(inode, mapping, 8166da61809SMark Fasheh OSYNC_METADATA|OSYNC_DATA); 8176da61809SMark Fasheh 8186da61809SMark Fasheh if (err) 8196da61809SMark Fasheh ret = err; 8206da61809SMark Fasheh } 82117ee4f49SJens Axboe balance_dirty_pages_ratelimited_nr(mapping, nr_pages); 8226da61809SMark Fasheh } 8236da61809SMark Fasheh 8246da61809SMark Fasheh return ret; 8256da61809SMark Fasheh } 8266da61809SMark Fasheh 8276da61809SMark Fasheh EXPORT_SYMBOL(generic_file_splice_write_nolock); 8286da61809SMark Fasheh 82983f9135bSJens Axboe /** 83083f9135bSJens Axboe * generic_file_splice_write - splice data from a pipe to a file 8313a326a2cSIngo Molnar * @pipe: pipe info 83283f9135bSJens Axboe * @out: file to write to 83383f9135bSJens Axboe * @len: number of bytes to splice 83483f9135bSJens Axboe * @flags: splice modifier flags 83583f9135bSJens Axboe * 83683f9135bSJens Axboe * Will either move or copy pages (determined by @flags options) from 83783f9135bSJens Axboe * the given pipe inode to the given file. 83883f9135bSJens Axboe * 83983f9135bSJens Axboe */ 8403a326a2cSIngo Molnar ssize_t 8413a326a2cSIngo Molnar generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out, 842cbb7e577SJens Axboe loff_t *ppos, size_t len, unsigned int flags) 8435274f052SJens Axboe { 8444f6f0bd2SJens Axboe struct address_space *mapping = out->f_mapping; 8458c34e2d6SJens Axboe struct inode *inode = mapping->host; 8463a326a2cSIngo Molnar ssize_t ret; 8478c34e2d6SJens Axboe int err; 8488c34e2d6SJens Axboe 8490f7fc9e4SJosef "Jeff" Sipek err = should_remove_suid(out->f_path.dentry); 8508c34e2d6SJens Axboe if (unlikely(err)) { 8518c34e2d6SJens Axboe mutex_lock(&inode->i_mutex); 8520f7fc9e4SJosef "Jeff" Sipek err = __remove_suid(out->f_path.dentry, err); 8538c34e2d6SJens Axboe mutex_unlock(&inode->i_mutex); 8548c34e2d6SJens Axboe if (err) 8558c34e2d6SJens Axboe return err; 8568c34e2d6SJens Axboe } 8573a326a2cSIngo Molnar 85800522fb4SJens Axboe ret = splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_file); 859a4514ebdSJens Axboe if (ret > 0) { 86017ee4f49SJens Axboe unsigned long nr_pages; 86117ee4f49SJens Axboe 862a4514ebdSJens Axboe *ppos += ret; 86317ee4f49SJens Axboe nr_pages = (ret + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; 8644f6f0bd2SJens Axboe 8654f6f0bd2SJens Axboe /* 866a4514ebdSJens Axboe * If file or inode is SYNC and we actually wrote some data, 867a4514ebdSJens Axboe * sync it. 8684f6f0bd2SJens Axboe */ 869a4514ebdSJens Axboe if (unlikely((out->f_flags & O_SYNC) || IS_SYNC(inode))) { 8704f6f0bd2SJens Axboe mutex_lock(&inode->i_mutex); 871a4514ebdSJens Axboe err = generic_osync_inode(inode, mapping, 8724f6f0bd2SJens Axboe OSYNC_METADATA|OSYNC_DATA); 8734f6f0bd2SJens Axboe mutex_unlock(&inode->i_mutex); 8744f6f0bd2SJens Axboe 8754f6f0bd2SJens Axboe if (err) 8764f6f0bd2SJens Axboe ret = err; 8774f6f0bd2SJens Axboe } 87817ee4f49SJens Axboe balance_dirty_pages_ratelimited_nr(mapping, nr_pages); 879a4514ebdSJens Axboe } 8804f6f0bd2SJens Axboe 8814f6f0bd2SJens Axboe return ret; 8825274f052SJens Axboe } 8835274f052SJens Axboe 884059a8f37SJens Axboe EXPORT_SYMBOL(generic_file_splice_write); 885059a8f37SJens Axboe 88683f9135bSJens Axboe /** 88783f9135bSJens Axboe * generic_splice_sendpage - splice data from a pipe to a socket 88883f9135bSJens Axboe * @inode: pipe inode 88983f9135bSJens Axboe * @out: socket to write to 89083f9135bSJens Axboe * @len: number of bytes to splice 89183f9135bSJens Axboe * @flags: splice modifier flags 89283f9135bSJens Axboe * 89383f9135bSJens Axboe * Will send @len bytes from the pipe to a network socket. No data copying 89483f9135bSJens Axboe * is involved. 89583f9135bSJens Axboe * 89683f9135bSJens Axboe */ 8973a326a2cSIngo Molnar ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, struct file *out, 898cbb7e577SJens Axboe loff_t *ppos, size_t len, unsigned int flags) 8995274f052SJens Axboe { 90000522fb4SJens Axboe return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_sendpage); 9015274f052SJens Axboe } 9025274f052SJens Axboe 903059a8f37SJens Axboe EXPORT_SYMBOL(generic_splice_sendpage); 904a0f06780SJeff Garzik 90583f9135bSJens Axboe /* 90683f9135bSJens Axboe * Attempt to initiate a splice from pipe to file. 90783f9135bSJens Axboe */ 9083a326a2cSIngo Molnar static long do_splice_from(struct pipe_inode_info *pipe, struct file *out, 909cbb7e577SJens Axboe loff_t *ppos, size_t len, unsigned int flags) 9105274f052SJens Axboe { 9115274f052SJens Axboe int ret; 9125274f052SJens Axboe 91349570e9bSJens Axboe if (unlikely(!out->f_op || !out->f_op->splice_write)) 9145274f052SJens Axboe return -EINVAL; 9155274f052SJens Axboe 91649570e9bSJens Axboe if (unlikely(!(out->f_mode & FMODE_WRITE))) 9175274f052SJens Axboe return -EBADF; 9185274f052SJens Axboe 919cbb7e577SJens Axboe ret = rw_verify_area(WRITE, out, ppos, len); 9205274f052SJens Axboe if (unlikely(ret < 0)) 9215274f052SJens Axboe return ret; 9225274f052SJens Axboe 923cbb7e577SJens Axboe return out->f_op->splice_write(pipe, out, ppos, len, flags); 9245274f052SJens Axboe } 9255274f052SJens Axboe 92683f9135bSJens Axboe /* 92783f9135bSJens Axboe * Attempt to initiate a splice from a file to a pipe. 92883f9135bSJens Axboe */ 929cbb7e577SJens Axboe static long do_splice_to(struct file *in, loff_t *ppos, 930cbb7e577SJens Axboe struct pipe_inode_info *pipe, size_t len, 931cbb7e577SJens Axboe unsigned int flags) 9325274f052SJens Axboe { 9335274f052SJens Axboe int ret; 9345274f052SJens Axboe 93549570e9bSJens Axboe if (unlikely(!in->f_op || !in->f_op->splice_read)) 9365274f052SJens Axboe return -EINVAL; 9375274f052SJens Axboe 93849570e9bSJens Axboe if (unlikely(!(in->f_mode & FMODE_READ))) 9395274f052SJens Axboe return -EBADF; 9405274f052SJens Axboe 941cbb7e577SJens Axboe ret = rw_verify_area(READ, in, ppos, len); 9425274f052SJens Axboe if (unlikely(ret < 0)) 9435274f052SJens Axboe return ret; 9445274f052SJens Axboe 945cbb7e577SJens Axboe return in->f_op->splice_read(in, ppos, pipe, len, flags); 9465274f052SJens Axboe } 9475274f052SJens Axboe 948c66ab6faSJens Axboe /* 949c66ab6faSJens Axboe * Splices from an input file to an actor, using a 'direct' pipe. 950c66ab6faSJens Axboe */ 951c66ab6faSJens Axboe ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd, 952c66ab6faSJens Axboe splice_direct_actor *actor) 953b92ce558SJens Axboe { 954b92ce558SJens Axboe struct pipe_inode_info *pipe; 955b92ce558SJens Axboe long ret, bytes; 956b92ce558SJens Axboe umode_t i_mode; 957c66ab6faSJens Axboe size_t len; 958c66ab6faSJens Axboe int i, flags; 959b92ce558SJens Axboe 960b92ce558SJens Axboe /* 961b92ce558SJens Axboe * We require the input being a regular file, as we don't want to 962b92ce558SJens Axboe * randomly drop data for eg socket -> socket splicing. Use the 963b92ce558SJens Axboe * piped splicing for that! 964b92ce558SJens Axboe */ 9650f7fc9e4SJosef "Jeff" Sipek i_mode = in->f_path.dentry->d_inode->i_mode; 966b92ce558SJens Axboe if (unlikely(!S_ISREG(i_mode) && !S_ISBLK(i_mode))) 967b92ce558SJens Axboe return -EINVAL; 968b92ce558SJens Axboe 969b92ce558SJens Axboe /* 970b92ce558SJens Axboe * neither in nor out is a pipe, setup an internal pipe attached to 971b92ce558SJens Axboe * 'out' and transfer the wanted data from 'in' to 'out' through that 972b92ce558SJens Axboe */ 973b92ce558SJens Axboe pipe = current->splice_pipe; 97449570e9bSJens Axboe if (unlikely(!pipe)) { 975b92ce558SJens Axboe pipe = alloc_pipe_info(NULL); 976b92ce558SJens Axboe if (!pipe) 977b92ce558SJens Axboe return -ENOMEM; 978b92ce558SJens Axboe 979b92ce558SJens Axboe /* 980b92ce558SJens Axboe * We don't have an immediate reader, but we'll read the stuff 98100522fb4SJens Axboe * out of the pipe right after the splice_to_pipe(). So set 982b92ce558SJens Axboe * PIPE_READERS appropriately. 983b92ce558SJens Axboe */ 984b92ce558SJens Axboe pipe->readers = 1; 985b92ce558SJens Axboe 986b92ce558SJens Axboe current->splice_pipe = pipe; 987b92ce558SJens Axboe } 988b92ce558SJens Axboe 989b92ce558SJens Axboe /* 99073d62d83SIngo Molnar * Do the splice. 991b92ce558SJens Axboe */ 992b92ce558SJens Axboe ret = 0; 993b92ce558SJens Axboe bytes = 0; 994c66ab6faSJens Axboe len = sd->total_len; 995c66ab6faSJens Axboe flags = sd->flags; 996c66ab6faSJens Axboe 997c66ab6faSJens Axboe /* 998c66ab6faSJens Axboe * Don't block on output, we have to drain the direct pipe. 999c66ab6faSJens Axboe */ 1000c66ab6faSJens Axboe sd->flags &= ~SPLICE_F_NONBLOCK; 1001b92ce558SJens Axboe 1002b92ce558SJens Axboe while (len) { 1003b92ce558SJens Axboe size_t read_len, max_read_len; 1004b92ce558SJens Axboe 1005b92ce558SJens Axboe /* 1006b92ce558SJens Axboe * Do at most PIPE_BUFFERS pages worth of transfer: 1007b92ce558SJens Axboe */ 1008b92ce558SJens Axboe max_read_len = min(len, (size_t)(PIPE_BUFFERS*PAGE_SIZE)); 1009b92ce558SJens Axboe 1010c66ab6faSJens Axboe ret = do_splice_to(in, &sd->pos, pipe, max_read_len, flags); 1011b92ce558SJens Axboe if (unlikely(ret < 0)) 1012b92ce558SJens Axboe goto out_release; 1013b92ce558SJens Axboe 1014b92ce558SJens Axboe read_len = ret; 1015c66ab6faSJens Axboe sd->total_len = read_len; 1016b92ce558SJens Axboe 1017b92ce558SJens Axboe /* 1018b92ce558SJens Axboe * NOTE: nonblocking mode only applies to the input. We 1019b92ce558SJens Axboe * must not do the output in nonblocking mode as then we 1020b92ce558SJens Axboe * could get stuck data in the internal pipe: 1021b92ce558SJens Axboe */ 1022c66ab6faSJens Axboe ret = actor(pipe, sd); 1023b92ce558SJens Axboe if (unlikely(ret < 0)) 1024b92ce558SJens Axboe goto out_release; 1025b92ce558SJens Axboe 1026b92ce558SJens Axboe bytes += ret; 1027b92ce558SJens Axboe len -= ret; 1028b92ce558SJens Axboe 1029b92ce558SJens Axboe /* 1030b92ce558SJens Axboe * In nonblocking mode, if we got back a short read then 1031b92ce558SJens Axboe * that was due to either an IO error or due to the 1032b92ce558SJens Axboe * pagecache entry not being there. In the IO error case 1033b92ce558SJens Axboe * the _next_ splice attempt will produce a clean IO error 1034b92ce558SJens Axboe * return value (not a short read), so in both cases it's 1035b92ce558SJens Axboe * correct to break out of the loop here: 1036b92ce558SJens Axboe */ 1037b92ce558SJens Axboe if ((flags & SPLICE_F_NONBLOCK) && (read_len < max_read_len)) 1038b92ce558SJens Axboe break; 1039b92ce558SJens Axboe } 1040b92ce558SJens Axboe 1041b92ce558SJens Axboe pipe->nrbufs = pipe->curbuf = 0; 1042b92ce558SJens Axboe 1043b92ce558SJens Axboe return bytes; 1044b92ce558SJens Axboe 1045b92ce558SJens Axboe out_release: 1046b92ce558SJens Axboe /* 1047b92ce558SJens Axboe * If we did an incomplete transfer we must release 1048b92ce558SJens Axboe * the pipe buffers in question: 1049b92ce558SJens Axboe */ 1050b92ce558SJens Axboe for (i = 0; i < PIPE_BUFFERS; i++) { 1051b92ce558SJens Axboe struct pipe_buffer *buf = pipe->bufs + i; 1052b92ce558SJens Axboe 1053b92ce558SJens Axboe if (buf->ops) { 1054b92ce558SJens Axboe buf->ops->release(pipe, buf); 1055b92ce558SJens Axboe buf->ops = NULL; 1056b92ce558SJens Axboe } 1057b92ce558SJens Axboe } 1058b92ce558SJens Axboe pipe->nrbufs = pipe->curbuf = 0; 1059b92ce558SJens Axboe 1060b92ce558SJens Axboe /* 1061b92ce558SJens Axboe * If we transferred some data, return the number of bytes: 1062b92ce558SJens Axboe */ 1063b92ce558SJens Axboe if (bytes > 0) 1064b92ce558SJens Axboe return bytes; 1065b92ce558SJens Axboe 1066b92ce558SJens Axboe return ret; 1067c66ab6faSJens Axboe 1068c66ab6faSJens Axboe } 1069c66ab6faSJens Axboe EXPORT_SYMBOL(splice_direct_to_actor); 1070c66ab6faSJens Axboe 1071c66ab6faSJens Axboe static int direct_splice_actor(struct pipe_inode_info *pipe, 1072c66ab6faSJens Axboe struct splice_desc *sd) 1073c66ab6faSJens Axboe { 10746a14b90bSJens Axboe struct file *file = sd->u.file; 1075c66ab6faSJens Axboe 1076c66ab6faSJens Axboe return do_splice_from(pipe, file, &sd->pos, sd->total_len, sd->flags); 1077c66ab6faSJens Axboe } 1078c66ab6faSJens Axboe 1079c66ab6faSJens Axboe long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, 1080c66ab6faSJens Axboe size_t len, unsigned int flags) 1081c66ab6faSJens Axboe { 1082c66ab6faSJens Axboe struct splice_desc sd = { 1083c66ab6faSJens Axboe .len = len, 1084c66ab6faSJens Axboe .total_len = len, 1085c66ab6faSJens Axboe .flags = flags, 1086c66ab6faSJens Axboe .pos = *ppos, 10876a14b90bSJens Axboe .u.file = out, 1088c66ab6faSJens Axboe }; 1089c66ab6faSJens Axboe size_t ret; 1090c66ab6faSJens Axboe 1091c66ab6faSJens Axboe ret = splice_direct_to_actor(in, &sd, direct_splice_actor); 1092c66ab6faSJens Axboe *ppos = sd.pos; 1093c66ab6faSJens Axboe return ret; 1094b92ce558SJens Axboe } 1095b92ce558SJens Axboe 109683f9135bSJens Axboe /* 1097ddac0d39SJens Axboe * After the inode slimming patch, i_pipe/i_bdev/i_cdev share the same 1098ddac0d39SJens Axboe * location, so checking ->i_pipe is not enough to verify that this is a 1099ddac0d39SJens Axboe * pipe. 1100ddac0d39SJens Axboe */ 1101ddac0d39SJens Axboe static inline struct pipe_inode_info *pipe_info(struct inode *inode) 1102ddac0d39SJens Axboe { 1103ddac0d39SJens Axboe if (S_ISFIFO(inode->i_mode)) 1104ddac0d39SJens Axboe return inode->i_pipe; 1105ddac0d39SJens Axboe 1106ddac0d39SJens Axboe return NULL; 1107ddac0d39SJens Axboe } 1108ddac0d39SJens Axboe 1109ddac0d39SJens Axboe /* 111083f9135bSJens Axboe * Determine where to splice to/from. 111183f9135bSJens Axboe */ 1112529565dcSIngo Molnar static long do_splice(struct file *in, loff_t __user *off_in, 1113529565dcSIngo Molnar struct file *out, loff_t __user *off_out, 1114529565dcSIngo Molnar size_t len, unsigned int flags) 11155274f052SJens Axboe { 11163a326a2cSIngo Molnar struct pipe_inode_info *pipe; 1117cbb7e577SJens Axboe loff_t offset, *off; 1118a4514ebdSJens Axboe long ret; 11195274f052SJens Axboe 11200f7fc9e4SJosef "Jeff" Sipek pipe = pipe_info(in->f_path.dentry->d_inode); 1121529565dcSIngo Molnar if (pipe) { 1122529565dcSIngo Molnar if (off_in) 1123529565dcSIngo Molnar return -ESPIPE; 1124b92ce558SJens Axboe if (off_out) { 1125b92ce558SJens Axboe if (out->f_op->llseek == no_llseek) 1126b92ce558SJens Axboe return -EINVAL; 1127cbb7e577SJens Axboe if (copy_from_user(&offset, off_out, sizeof(loff_t))) 1128b92ce558SJens Axboe return -EFAULT; 1129cbb7e577SJens Axboe off = &offset; 1130cbb7e577SJens Axboe } else 1131cbb7e577SJens Axboe off = &out->f_pos; 1132529565dcSIngo Molnar 1133a4514ebdSJens Axboe ret = do_splice_from(pipe, out, off, len, flags); 1134a4514ebdSJens Axboe 1135a4514ebdSJens Axboe if (off_out && copy_to_user(off_out, off, sizeof(loff_t))) 1136a4514ebdSJens Axboe ret = -EFAULT; 1137a4514ebdSJens Axboe 1138a4514ebdSJens Axboe return ret; 1139529565dcSIngo Molnar } 11405274f052SJens Axboe 11410f7fc9e4SJosef "Jeff" Sipek pipe = pipe_info(out->f_path.dentry->d_inode); 1142529565dcSIngo Molnar if (pipe) { 1143529565dcSIngo Molnar if (off_out) 1144529565dcSIngo Molnar return -ESPIPE; 1145b92ce558SJens Axboe if (off_in) { 1146b92ce558SJens Axboe if (in->f_op->llseek == no_llseek) 1147b92ce558SJens Axboe return -EINVAL; 1148cbb7e577SJens Axboe if (copy_from_user(&offset, off_in, sizeof(loff_t))) 1149b92ce558SJens Axboe return -EFAULT; 1150cbb7e577SJens Axboe off = &offset; 1151cbb7e577SJens Axboe } else 1152cbb7e577SJens Axboe off = &in->f_pos; 1153529565dcSIngo Molnar 1154a4514ebdSJens Axboe ret = do_splice_to(in, off, pipe, len, flags); 1155a4514ebdSJens Axboe 1156a4514ebdSJens Axboe if (off_in && copy_to_user(off_in, off, sizeof(loff_t))) 1157a4514ebdSJens Axboe ret = -EFAULT; 1158a4514ebdSJens Axboe 1159a4514ebdSJens Axboe return ret; 1160529565dcSIngo Molnar } 11615274f052SJens Axboe 11625274f052SJens Axboe return -EINVAL; 11635274f052SJens Axboe } 11645274f052SJens Axboe 1165912d35f8SJens Axboe /* 1166912d35f8SJens Axboe * Map an iov into an array of pages and offset/length tupples. With the 1167912d35f8SJens Axboe * partial_page structure, we can map several non-contiguous ranges into 1168912d35f8SJens Axboe * our ones pages[] map instead of splitting that operation into pieces. 1169912d35f8SJens Axboe * Could easily be exported as a generic helper for other users, in which 1170912d35f8SJens Axboe * case one would probably want to add a 'max_nr_pages' parameter as well. 1171912d35f8SJens Axboe */ 1172912d35f8SJens Axboe static int get_iovec_page_array(const struct iovec __user *iov, 1173912d35f8SJens Axboe unsigned int nr_vecs, struct page **pages, 11747afa6fd0SJens Axboe struct partial_page *partial, int aligned) 1175912d35f8SJens Axboe { 1176912d35f8SJens Axboe int buffers = 0, error = 0; 1177912d35f8SJens Axboe 1178912d35f8SJens Axboe /* 1179912d35f8SJens Axboe * It's ok to take the mmap_sem for reading, even 1180912d35f8SJens Axboe * across a "get_user()". 1181912d35f8SJens Axboe */ 1182912d35f8SJens Axboe down_read(¤t->mm->mmap_sem); 1183912d35f8SJens Axboe 1184912d35f8SJens Axboe while (nr_vecs) { 1185912d35f8SJens Axboe unsigned long off, npages; 1186912d35f8SJens Axboe void __user *base; 1187912d35f8SJens Axboe size_t len; 1188912d35f8SJens Axboe int i; 1189912d35f8SJens Axboe 1190912d35f8SJens Axboe /* 1191912d35f8SJens Axboe * Get user address base and length for this iovec. 1192912d35f8SJens Axboe */ 1193912d35f8SJens Axboe error = get_user(base, &iov->iov_base); 1194912d35f8SJens Axboe if (unlikely(error)) 1195912d35f8SJens Axboe break; 1196912d35f8SJens Axboe error = get_user(len, &iov->iov_len); 1197912d35f8SJens Axboe if (unlikely(error)) 1198912d35f8SJens Axboe break; 1199912d35f8SJens Axboe 1200912d35f8SJens Axboe /* 1201912d35f8SJens Axboe * Sanity check this iovec. 0 read succeeds. 1202912d35f8SJens Axboe */ 1203912d35f8SJens Axboe if (unlikely(!len)) 1204912d35f8SJens Axboe break; 1205912d35f8SJens Axboe error = -EFAULT; 1206912d35f8SJens Axboe if (unlikely(!base)) 1207912d35f8SJens Axboe break; 1208912d35f8SJens Axboe 1209912d35f8SJens Axboe /* 1210912d35f8SJens Axboe * Get this base offset and number of pages, then map 1211912d35f8SJens Axboe * in the user pages. 1212912d35f8SJens Axboe */ 1213912d35f8SJens Axboe off = (unsigned long) base & ~PAGE_MASK; 12147afa6fd0SJens Axboe 12157afa6fd0SJens Axboe /* 12167afa6fd0SJens Axboe * If asked for alignment, the offset must be zero and the 12177afa6fd0SJens Axboe * length a multiple of the PAGE_SIZE. 12187afa6fd0SJens Axboe */ 12197afa6fd0SJens Axboe error = -EINVAL; 12207afa6fd0SJens Axboe if (aligned && (off || len & ~PAGE_MASK)) 12217afa6fd0SJens Axboe break; 12227afa6fd0SJens Axboe 1223912d35f8SJens Axboe npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT; 1224912d35f8SJens Axboe if (npages > PIPE_BUFFERS - buffers) 1225912d35f8SJens Axboe npages = PIPE_BUFFERS - buffers; 1226912d35f8SJens Axboe 1227912d35f8SJens Axboe error = get_user_pages(current, current->mm, 1228912d35f8SJens Axboe (unsigned long) base, npages, 0, 0, 1229912d35f8SJens Axboe &pages[buffers], NULL); 1230912d35f8SJens Axboe 1231912d35f8SJens Axboe if (unlikely(error <= 0)) 1232912d35f8SJens Axboe break; 1233912d35f8SJens Axboe 1234912d35f8SJens Axboe /* 1235912d35f8SJens Axboe * Fill this contiguous range into the partial page map. 1236912d35f8SJens Axboe */ 1237912d35f8SJens Axboe for (i = 0; i < error; i++) { 12387591489aSJens Axboe const int plen = min_t(size_t, len, PAGE_SIZE - off); 1239912d35f8SJens Axboe 1240912d35f8SJens Axboe partial[buffers].offset = off; 1241912d35f8SJens Axboe partial[buffers].len = plen; 1242912d35f8SJens Axboe 1243912d35f8SJens Axboe off = 0; 1244912d35f8SJens Axboe len -= plen; 1245912d35f8SJens Axboe buffers++; 1246912d35f8SJens Axboe } 1247912d35f8SJens Axboe 1248912d35f8SJens Axboe /* 1249912d35f8SJens Axboe * We didn't complete this iov, stop here since it probably 1250912d35f8SJens Axboe * means we have to move some of this into a pipe to 1251912d35f8SJens Axboe * be able to continue. 1252912d35f8SJens Axboe */ 1253912d35f8SJens Axboe if (len) 1254912d35f8SJens Axboe break; 1255912d35f8SJens Axboe 1256912d35f8SJens Axboe /* 1257912d35f8SJens Axboe * Don't continue if we mapped fewer pages than we asked for, 1258912d35f8SJens Axboe * or if we mapped the max number of pages that we have 1259912d35f8SJens Axboe * room for. 1260912d35f8SJens Axboe */ 1261912d35f8SJens Axboe if (error < npages || buffers == PIPE_BUFFERS) 1262912d35f8SJens Axboe break; 1263912d35f8SJens Axboe 1264912d35f8SJens Axboe nr_vecs--; 1265912d35f8SJens Axboe iov++; 1266912d35f8SJens Axboe } 1267912d35f8SJens Axboe 1268912d35f8SJens Axboe up_read(¤t->mm->mmap_sem); 1269912d35f8SJens Axboe 1270912d35f8SJens Axboe if (buffers) 1271912d35f8SJens Axboe return buffers; 1272912d35f8SJens Axboe 1273912d35f8SJens Axboe return error; 1274912d35f8SJens Axboe } 1275912d35f8SJens Axboe 12766a14b90bSJens Axboe static int pipe_to_user(struct pipe_inode_info *pipe, struct pipe_buffer *buf, 12776a14b90bSJens Axboe struct splice_desc *sd) 12786a14b90bSJens Axboe { 12796a14b90bSJens Axboe char *src; 12806a14b90bSJens Axboe int ret; 12816a14b90bSJens Axboe 12826a14b90bSJens Axboe ret = buf->ops->pin(pipe, buf); 12836a14b90bSJens Axboe if (unlikely(ret)) 12846a14b90bSJens Axboe return ret; 12856a14b90bSJens Axboe 12866a14b90bSJens Axboe /* 12876a14b90bSJens Axboe * See if we can use the atomic maps, by prefaulting in the 12886a14b90bSJens Axboe * pages and doing an atomic copy 12896a14b90bSJens Axboe */ 12906a14b90bSJens Axboe if (!fault_in_pages_writeable(sd->u.userptr, sd->len)) { 12916a14b90bSJens Axboe src = buf->ops->map(pipe, buf, 1); 12926a14b90bSJens Axboe ret = __copy_to_user_inatomic(sd->u.userptr, src + buf->offset, 12936a14b90bSJens Axboe sd->len); 12946a14b90bSJens Axboe buf->ops->unmap(pipe, buf, src); 12956a14b90bSJens Axboe if (!ret) { 12966a14b90bSJens Axboe ret = sd->len; 12976a14b90bSJens Axboe goto out; 12986a14b90bSJens Axboe } 12996a14b90bSJens Axboe } 13006a14b90bSJens Axboe 13016a14b90bSJens Axboe /* 13026a14b90bSJens Axboe * No dice, use slow non-atomic map and copy 13036a14b90bSJens Axboe */ 13046a14b90bSJens Axboe src = buf->ops->map(pipe, buf, 0); 13056a14b90bSJens Axboe 13066a14b90bSJens Axboe ret = sd->len; 13076a14b90bSJens Axboe if (copy_to_user(sd->u.userptr, src + buf->offset, sd->len)) 13086a14b90bSJens Axboe ret = -EFAULT; 13096a14b90bSJens Axboe 13106a14b90bSJens Axboe out: 13116a14b90bSJens Axboe if (ret > 0) 13126a14b90bSJens Axboe sd->u.userptr += ret; 13136a14b90bSJens Axboe buf->ops->unmap(pipe, buf, src); 13146a14b90bSJens Axboe return ret; 13156a14b90bSJens Axboe } 13166a14b90bSJens Axboe 13176a14b90bSJens Axboe /* 13186a14b90bSJens Axboe * For lack of a better implementation, implement vmsplice() to userspace 13196a14b90bSJens Axboe * as a simple copy of the pipes pages to the user iov. 13206a14b90bSJens Axboe */ 13216a14b90bSJens Axboe static long vmsplice_to_user(struct file *file, const struct iovec __user *iov, 13226a14b90bSJens Axboe unsigned long nr_segs, unsigned int flags) 13236a14b90bSJens Axboe { 13246a14b90bSJens Axboe struct pipe_inode_info *pipe; 13256a14b90bSJens Axboe struct splice_desc sd; 13266a14b90bSJens Axboe ssize_t size; 13276a14b90bSJens Axboe int error; 13286a14b90bSJens Axboe long ret; 13296a14b90bSJens Axboe 13306a14b90bSJens Axboe pipe = pipe_info(file->f_path.dentry->d_inode); 13316a14b90bSJens Axboe if (!pipe) 13326a14b90bSJens Axboe return -EBADF; 13336a14b90bSJens Axboe 13346a14b90bSJens Axboe if (pipe->inode) 13356a14b90bSJens Axboe mutex_lock(&pipe->inode->i_mutex); 13366a14b90bSJens Axboe 13376a14b90bSJens Axboe error = ret = 0; 13386a14b90bSJens Axboe while (nr_segs) { 13396a14b90bSJens Axboe void __user *base; 13406a14b90bSJens Axboe size_t len; 13416a14b90bSJens Axboe 13426a14b90bSJens Axboe /* 13436a14b90bSJens Axboe * Get user address base and length for this iovec. 13446a14b90bSJens Axboe */ 13456a14b90bSJens Axboe error = get_user(base, &iov->iov_base); 13466a14b90bSJens Axboe if (unlikely(error)) 13476a14b90bSJens Axboe break; 13486a14b90bSJens Axboe error = get_user(len, &iov->iov_len); 13496a14b90bSJens Axboe if (unlikely(error)) 13506a14b90bSJens Axboe break; 13516a14b90bSJens Axboe 13526a14b90bSJens Axboe /* 13536a14b90bSJens Axboe * Sanity check this iovec. 0 read succeeds. 13546a14b90bSJens Axboe */ 13556a14b90bSJens Axboe if (unlikely(!len)) 13566a14b90bSJens Axboe break; 13576a14b90bSJens Axboe if (unlikely(!base)) { 13586a14b90bSJens Axboe error = -EFAULT; 13596a14b90bSJens Axboe break; 13606a14b90bSJens Axboe } 13616a14b90bSJens Axboe 13626a14b90bSJens Axboe sd.len = 0; 13636a14b90bSJens Axboe sd.total_len = len; 13646a14b90bSJens Axboe sd.flags = flags; 13656a14b90bSJens Axboe sd.u.userptr = base; 13666a14b90bSJens Axboe sd.pos = 0; 13676a14b90bSJens Axboe 13686a14b90bSJens Axboe size = __splice_from_pipe(pipe, &sd, pipe_to_user); 13696a14b90bSJens Axboe if (size < 0) { 13706a14b90bSJens Axboe if (!ret) 13716a14b90bSJens Axboe ret = size; 13726a14b90bSJens Axboe 13736a14b90bSJens Axboe break; 13746a14b90bSJens Axboe } 13756a14b90bSJens Axboe 13766a14b90bSJens Axboe ret += size; 13776a14b90bSJens Axboe 13786a14b90bSJens Axboe if (size < len) 13796a14b90bSJens Axboe break; 13806a14b90bSJens Axboe 13816a14b90bSJens Axboe nr_segs--; 13826a14b90bSJens Axboe iov++; 13836a14b90bSJens Axboe } 13846a14b90bSJens Axboe 13856a14b90bSJens Axboe if (pipe->inode) 13866a14b90bSJens Axboe mutex_unlock(&pipe->inode->i_mutex); 13876a14b90bSJens Axboe 13886a14b90bSJens Axboe if (!ret) 13896a14b90bSJens Axboe ret = error; 13906a14b90bSJens Axboe 13916a14b90bSJens Axboe return ret; 13926a14b90bSJens Axboe } 13936a14b90bSJens Axboe 1394912d35f8SJens Axboe /* 1395912d35f8SJens Axboe * vmsplice splices a user address range into a pipe. It can be thought of 1396912d35f8SJens Axboe * as splice-from-memory, where the regular splice is splice-from-file (or 1397912d35f8SJens Axboe * to file). In both cases the output is a pipe, naturally. 1398912d35f8SJens Axboe */ 13996a14b90bSJens Axboe static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov, 1400912d35f8SJens Axboe unsigned long nr_segs, unsigned int flags) 1401912d35f8SJens Axboe { 1402ddac0d39SJens Axboe struct pipe_inode_info *pipe; 1403912d35f8SJens Axboe struct page *pages[PIPE_BUFFERS]; 1404912d35f8SJens Axboe struct partial_page partial[PIPE_BUFFERS]; 1405912d35f8SJens Axboe struct splice_pipe_desc spd = { 1406912d35f8SJens Axboe .pages = pages, 1407912d35f8SJens Axboe .partial = partial, 1408912d35f8SJens Axboe .flags = flags, 1409912d35f8SJens Axboe .ops = &user_page_pipe_buf_ops, 1410912d35f8SJens Axboe }; 1411912d35f8SJens Axboe 14120f7fc9e4SJosef "Jeff" Sipek pipe = pipe_info(file->f_path.dentry->d_inode); 1413ddac0d39SJens Axboe if (!pipe) 1414912d35f8SJens Axboe return -EBADF; 1415912d35f8SJens Axboe 14167afa6fd0SJens Axboe spd.nr_pages = get_iovec_page_array(iov, nr_segs, pages, partial, 14177afa6fd0SJens Axboe flags & SPLICE_F_GIFT); 1418912d35f8SJens Axboe if (spd.nr_pages <= 0) 1419912d35f8SJens Axboe return spd.nr_pages; 1420912d35f8SJens Axboe 142100522fb4SJens Axboe return splice_to_pipe(pipe, &spd); 1422912d35f8SJens Axboe } 1423912d35f8SJens Axboe 14246a14b90bSJens Axboe /* 14256a14b90bSJens Axboe * Note that vmsplice only really supports true splicing _from_ user memory 14266a14b90bSJens Axboe * to a pipe, not the other way around. Splicing from user memory is a simple 14276a14b90bSJens Axboe * operation that can be supported without any funky alignment restrictions 14286a14b90bSJens Axboe * or nasty vm tricks. We simply map in the user memory and fill them into 14296a14b90bSJens Axboe * a pipe. The reverse isn't quite as easy, though. There are two possible 14306a14b90bSJens Axboe * solutions for that: 14316a14b90bSJens Axboe * 14326a14b90bSJens Axboe * - memcpy() the data internally, at which point we might as well just 14336a14b90bSJens Axboe * do a regular read() on the buffer anyway. 14346a14b90bSJens Axboe * - Lots of nasty vm tricks, that are neither fast nor flexible (it 14356a14b90bSJens Axboe * has restriction limitations on both ends of the pipe). 14366a14b90bSJens Axboe * 14376a14b90bSJens Axboe * Currently we punt and implement it as a normal copy, see pipe_to_user(). 14386a14b90bSJens Axboe * 14396a14b90bSJens Axboe */ 1440912d35f8SJens Axboe asmlinkage long sys_vmsplice(int fd, const struct iovec __user *iov, 1441912d35f8SJens Axboe unsigned long nr_segs, unsigned int flags) 1442912d35f8SJens Axboe { 1443912d35f8SJens Axboe struct file *file; 1444912d35f8SJens Axboe long error; 1445912d35f8SJens Axboe int fput; 1446912d35f8SJens Axboe 14476a14b90bSJens Axboe if (unlikely(nr_segs > UIO_MAXIOV)) 14486a14b90bSJens Axboe return -EINVAL; 14496a14b90bSJens Axboe else if (unlikely(!nr_segs)) 14506a14b90bSJens Axboe return 0; 14516a14b90bSJens Axboe 1452912d35f8SJens Axboe error = -EBADF; 1453912d35f8SJens Axboe file = fget_light(fd, &fput); 1454912d35f8SJens Axboe if (file) { 1455912d35f8SJens Axboe if (file->f_mode & FMODE_WRITE) 14566a14b90bSJens Axboe error = vmsplice_to_pipe(file, iov, nr_segs, flags); 14576a14b90bSJens Axboe else if (file->f_mode & FMODE_READ) 14586a14b90bSJens Axboe error = vmsplice_to_user(file, iov, nr_segs, flags); 1459912d35f8SJens Axboe 1460912d35f8SJens Axboe fput_light(file, fput); 1461912d35f8SJens Axboe } 1462912d35f8SJens Axboe 1463912d35f8SJens Axboe return error; 1464912d35f8SJens Axboe } 1465912d35f8SJens Axboe 1466529565dcSIngo Molnar asmlinkage long sys_splice(int fd_in, loff_t __user *off_in, 1467529565dcSIngo Molnar int fd_out, loff_t __user *off_out, 1468529565dcSIngo Molnar size_t len, unsigned int flags) 14695274f052SJens Axboe { 14705274f052SJens Axboe long error; 14715274f052SJens Axboe struct file *in, *out; 14725274f052SJens Axboe int fput_in, fput_out; 14735274f052SJens Axboe 14745274f052SJens Axboe if (unlikely(!len)) 14755274f052SJens Axboe return 0; 14765274f052SJens Axboe 14775274f052SJens Axboe error = -EBADF; 1478529565dcSIngo Molnar in = fget_light(fd_in, &fput_in); 14795274f052SJens Axboe if (in) { 14805274f052SJens Axboe if (in->f_mode & FMODE_READ) { 1481529565dcSIngo Molnar out = fget_light(fd_out, &fput_out); 14825274f052SJens Axboe if (out) { 14835274f052SJens Axboe if (out->f_mode & FMODE_WRITE) 1484529565dcSIngo Molnar error = do_splice(in, off_in, 1485529565dcSIngo Molnar out, off_out, 1486529565dcSIngo Molnar len, flags); 14875274f052SJens Axboe fput_light(out, fput_out); 14885274f052SJens Axboe } 14895274f052SJens Axboe } 14905274f052SJens Axboe 14915274f052SJens Axboe fput_light(in, fput_in); 14925274f052SJens Axboe } 14935274f052SJens Axboe 14945274f052SJens Axboe return error; 14955274f052SJens Axboe } 149670524490SJens Axboe 149770524490SJens Axboe /* 1498aadd06e5SJens Axboe * Make sure there's data to read. Wait for input if we can, otherwise 1499aadd06e5SJens Axboe * return an appropriate error. 1500aadd06e5SJens Axboe */ 1501aadd06e5SJens Axboe static int link_ipipe_prep(struct pipe_inode_info *pipe, unsigned int flags) 1502aadd06e5SJens Axboe { 1503aadd06e5SJens Axboe int ret; 1504aadd06e5SJens Axboe 1505aadd06e5SJens Axboe /* 1506aadd06e5SJens Axboe * Check ->nrbufs without the inode lock first. This function 1507aadd06e5SJens Axboe * is speculative anyways, so missing one is ok. 1508aadd06e5SJens Axboe */ 1509aadd06e5SJens Axboe if (pipe->nrbufs) 1510aadd06e5SJens Axboe return 0; 1511aadd06e5SJens Axboe 1512aadd06e5SJens Axboe ret = 0; 1513aadd06e5SJens Axboe mutex_lock(&pipe->inode->i_mutex); 1514aadd06e5SJens Axboe 1515aadd06e5SJens Axboe while (!pipe->nrbufs) { 1516aadd06e5SJens Axboe if (signal_pending(current)) { 1517aadd06e5SJens Axboe ret = -ERESTARTSYS; 1518aadd06e5SJens Axboe break; 1519aadd06e5SJens Axboe } 1520aadd06e5SJens Axboe if (!pipe->writers) 1521aadd06e5SJens Axboe break; 1522aadd06e5SJens Axboe if (!pipe->waiting_writers) { 1523aadd06e5SJens Axboe if (flags & SPLICE_F_NONBLOCK) { 1524aadd06e5SJens Axboe ret = -EAGAIN; 1525aadd06e5SJens Axboe break; 1526aadd06e5SJens Axboe } 1527aadd06e5SJens Axboe } 1528aadd06e5SJens Axboe pipe_wait(pipe); 1529aadd06e5SJens Axboe } 1530aadd06e5SJens Axboe 1531aadd06e5SJens Axboe mutex_unlock(&pipe->inode->i_mutex); 1532aadd06e5SJens Axboe return ret; 1533aadd06e5SJens Axboe } 1534aadd06e5SJens Axboe 1535aadd06e5SJens Axboe /* 1536aadd06e5SJens Axboe * Make sure there's writeable room. Wait for room if we can, otherwise 1537aadd06e5SJens Axboe * return an appropriate error. 1538aadd06e5SJens Axboe */ 1539aadd06e5SJens Axboe static int link_opipe_prep(struct pipe_inode_info *pipe, unsigned int flags) 1540aadd06e5SJens Axboe { 1541aadd06e5SJens Axboe int ret; 1542aadd06e5SJens Axboe 1543aadd06e5SJens Axboe /* 1544aadd06e5SJens Axboe * Check ->nrbufs without the inode lock first. This function 1545aadd06e5SJens Axboe * is speculative anyways, so missing one is ok. 1546aadd06e5SJens Axboe */ 1547aadd06e5SJens Axboe if (pipe->nrbufs < PIPE_BUFFERS) 1548aadd06e5SJens Axboe return 0; 1549aadd06e5SJens Axboe 1550aadd06e5SJens Axboe ret = 0; 1551aadd06e5SJens Axboe mutex_lock(&pipe->inode->i_mutex); 1552aadd06e5SJens Axboe 1553aadd06e5SJens Axboe while (pipe->nrbufs >= PIPE_BUFFERS) { 1554aadd06e5SJens Axboe if (!pipe->readers) { 1555aadd06e5SJens Axboe send_sig(SIGPIPE, current, 0); 1556aadd06e5SJens Axboe ret = -EPIPE; 1557aadd06e5SJens Axboe break; 1558aadd06e5SJens Axboe } 1559aadd06e5SJens Axboe if (flags & SPLICE_F_NONBLOCK) { 1560aadd06e5SJens Axboe ret = -EAGAIN; 1561aadd06e5SJens Axboe break; 1562aadd06e5SJens Axboe } 1563aadd06e5SJens Axboe if (signal_pending(current)) { 1564aadd06e5SJens Axboe ret = -ERESTARTSYS; 1565aadd06e5SJens Axboe break; 1566aadd06e5SJens Axboe } 1567aadd06e5SJens Axboe pipe->waiting_writers++; 1568aadd06e5SJens Axboe pipe_wait(pipe); 1569aadd06e5SJens Axboe pipe->waiting_writers--; 1570aadd06e5SJens Axboe } 1571aadd06e5SJens Axboe 1572aadd06e5SJens Axboe mutex_unlock(&pipe->inode->i_mutex); 1573aadd06e5SJens Axboe return ret; 1574aadd06e5SJens Axboe } 1575aadd06e5SJens Axboe 1576aadd06e5SJens Axboe /* 157770524490SJens Axboe * Link contents of ipipe to opipe. 157870524490SJens Axboe */ 157970524490SJens Axboe static int link_pipe(struct pipe_inode_info *ipipe, 158070524490SJens Axboe struct pipe_inode_info *opipe, 158170524490SJens Axboe size_t len, unsigned int flags) 158270524490SJens Axboe { 158370524490SJens Axboe struct pipe_buffer *ibuf, *obuf; 1584aadd06e5SJens Axboe int ret = 0, i = 0, nbuf; 158570524490SJens Axboe 158670524490SJens Axboe /* 158770524490SJens Axboe * Potential ABBA deadlock, work around it by ordering lock 158870524490SJens Axboe * grabbing by inode address. Otherwise two different processes 158970524490SJens Axboe * could deadlock (one doing tee from A -> B, the other from B -> A). 159070524490SJens Axboe */ 159162752ee1SMark Fasheh inode_double_lock(ipipe->inode, opipe->inode); 159270524490SJens Axboe 1593aadd06e5SJens Axboe do { 159470524490SJens Axboe if (!opipe->readers) { 159570524490SJens Axboe send_sig(SIGPIPE, current, 0); 159670524490SJens Axboe if (!ret) 159770524490SJens Axboe ret = -EPIPE; 159870524490SJens Axboe break; 159970524490SJens Axboe } 160070524490SJens Axboe 160170524490SJens Axboe /* 1602aadd06e5SJens Axboe * If we have iterated all input buffers or ran out of 1603aadd06e5SJens Axboe * output room, break. 160470524490SJens Axboe */ 1605aadd06e5SJens Axboe if (i >= ipipe->nrbufs || opipe->nrbufs >= PIPE_BUFFERS) 1606aadd06e5SJens Axboe break; 1607aadd06e5SJens Axboe 1608aadd06e5SJens Axboe ibuf = ipipe->bufs + ((ipipe->curbuf + i) & (PIPE_BUFFERS - 1)); 1609aadd06e5SJens Axboe nbuf = (opipe->curbuf + opipe->nrbufs) & (PIPE_BUFFERS - 1); 161070524490SJens Axboe 161170524490SJens Axboe /* 161270524490SJens Axboe * Get a reference to this pipe buffer, 161370524490SJens Axboe * so we can copy the contents over. 161470524490SJens Axboe */ 161570524490SJens Axboe ibuf->ops->get(ipipe, ibuf); 161670524490SJens Axboe 161770524490SJens Axboe obuf = opipe->bufs + nbuf; 161870524490SJens Axboe *obuf = *ibuf; 161970524490SJens Axboe 16207afa6fd0SJens Axboe /* 16217afa6fd0SJens Axboe * Don't inherit the gift flag, we need to 16227afa6fd0SJens Axboe * prevent multiple steals of this page. 16237afa6fd0SJens Axboe */ 16247afa6fd0SJens Axboe obuf->flags &= ~PIPE_BUF_FLAG_GIFT; 16257afa6fd0SJens Axboe 162670524490SJens Axboe if (obuf->len > len) 162770524490SJens Axboe obuf->len = len; 162870524490SJens Axboe 162970524490SJens Axboe opipe->nrbufs++; 163070524490SJens Axboe ret += obuf->len; 163170524490SJens Axboe len -= obuf->len; 1632aadd06e5SJens Axboe i++; 1633aadd06e5SJens Axboe } while (len); 163470524490SJens Axboe 163562752ee1SMark Fasheh inode_double_unlock(ipipe->inode, opipe->inode); 163670524490SJens Axboe 1637aadd06e5SJens Axboe /* 1638aadd06e5SJens Axboe * If we put data in the output pipe, wakeup any potential readers. 1639aadd06e5SJens Axboe */ 1640aadd06e5SJens Axboe if (ret > 0) { 164170524490SJens Axboe smp_mb(); 164270524490SJens Axboe if (waitqueue_active(&opipe->wait)) 164370524490SJens Axboe wake_up_interruptible(&opipe->wait); 164470524490SJens Axboe kill_fasync(&opipe->fasync_readers, SIGIO, POLL_IN); 164570524490SJens Axboe } 164670524490SJens Axboe 164770524490SJens Axboe return ret; 164870524490SJens Axboe } 164970524490SJens Axboe 165070524490SJens Axboe /* 165170524490SJens Axboe * This is a tee(1) implementation that works on pipes. It doesn't copy 165270524490SJens Axboe * any data, it simply references the 'in' pages on the 'out' pipe. 165370524490SJens Axboe * The 'flags' used are the SPLICE_F_* variants, currently the only 165470524490SJens Axboe * applicable one is SPLICE_F_NONBLOCK. 165570524490SJens Axboe */ 165670524490SJens Axboe static long do_tee(struct file *in, struct file *out, size_t len, 165770524490SJens Axboe unsigned int flags) 165870524490SJens Axboe { 16590f7fc9e4SJosef "Jeff" Sipek struct pipe_inode_info *ipipe = pipe_info(in->f_path.dentry->d_inode); 16600f7fc9e4SJosef "Jeff" Sipek struct pipe_inode_info *opipe = pipe_info(out->f_path.dentry->d_inode); 1661aadd06e5SJens Axboe int ret = -EINVAL; 166270524490SJens Axboe 166370524490SJens Axboe /* 1664aadd06e5SJens Axboe * Duplicate the contents of ipipe to opipe without actually 1665aadd06e5SJens Axboe * copying the data. 166670524490SJens Axboe */ 1667aadd06e5SJens Axboe if (ipipe && opipe && ipipe != opipe) { 1668aadd06e5SJens Axboe /* 1669aadd06e5SJens Axboe * Keep going, unless we encounter an error. The ipipe/opipe 1670aadd06e5SJens Axboe * ordering doesn't really matter. 1671aadd06e5SJens Axboe */ 1672aadd06e5SJens Axboe ret = link_ipipe_prep(ipipe, flags); 1673aadd06e5SJens Axboe if (!ret) { 1674aadd06e5SJens Axboe ret = link_opipe_prep(opipe, flags); 1675aadd06e5SJens Axboe if (!ret) { 1676aadd06e5SJens Axboe ret = link_pipe(ipipe, opipe, len, flags); 1677aadd06e5SJens Axboe if (!ret && (flags & SPLICE_F_NONBLOCK)) 1678aadd06e5SJens Axboe ret = -EAGAIN; 1679aadd06e5SJens Axboe } 1680aadd06e5SJens Axboe } 1681aadd06e5SJens Axboe } 168270524490SJens Axboe 1683aadd06e5SJens Axboe return ret; 168470524490SJens Axboe } 168570524490SJens Axboe 168670524490SJens Axboe asmlinkage long sys_tee(int fdin, int fdout, size_t len, unsigned int flags) 168770524490SJens Axboe { 168870524490SJens Axboe struct file *in; 168970524490SJens Axboe int error, fput_in; 169070524490SJens Axboe 169170524490SJens Axboe if (unlikely(!len)) 169270524490SJens Axboe return 0; 169370524490SJens Axboe 169470524490SJens Axboe error = -EBADF; 169570524490SJens Axboe in = fget_light(fdin, &fput_in); 169670524490SJens Axboe if (in) { 169770524490SJens Axboe if (in->f_mode & FMODE_READ) { 169870524490SJens Axboe int fput_out; 169970524490SJens Axboe struct file *out = fget_light(fdout, &fput_out); 170070524490SJens Axboe 170170524490SJens Axboe if (out) { 170270524490SJens Axboe if (out->f_mode & FMODE_WRITE) 170370524490SJens Axboe error = do_tee(in, out, len, flags); 170470524490SJens Axboe fput_light(out, fput_out); 170570524490SJens Axboe } 170670524490SJens Axboe } 170770524490SJens Axboe fput_light(in, fput_in); 170870524490SJens Axboe } 170970524490SJens Axboe 171070524490SJens Axboe return error; 171170524490SJens Axboe } 1712