This is a forward port to 2.6.34 of this patch from Jens: http://git.kernel.dk/?p=linux-2.6-block.git;a=commitdiff_plain;h=24547ac4d97bebb58caf9ce58bd507a95c812a3f One issue I see is that it's possible to grow pipes indefinitely. Should this be restricted to privileged users? Thanks, Miklos From: Jens Axboe <jens.axboe@xxxxxxxxxx> This patch adds F_GETPIPE_SZ and F_SETPIPE_SZ fcntl() actions for growing and shrinking the size of a pipe and adjusts pipe.c and splice.c (and relay and network splice) usage to work with these larger (or smaller) pipes. Signed-off-by: Jens Axboe <jens.axboe@xxxxxxxxxx> Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx> --- fs/fcntl.c | 5 + fs/pipe.c | 107 ++++++++++++++++++++++++++--- fs/splice.c | 160 +++++++++++++++++++++++++++++--------------- include/asm-generic/fcntl.h | 7 + include/linux/pipe_fs_i.h | 11 +-- include/linux/splice.h | 7 + kernel/relay.c | 19 +++-- kernel/trace/trace.c | 60 +++++++++------- net/core/skbuff.c | 39 ++++++---- 9 files changed, 299 insertions(+), 116 deletions(-) Index: linux-2.6/fs/fcntl.c =================================================================== --- linux-2.6.orig/fs/fcntl.c 2010-05-14 18:23:05.000000000 +0200 +++ linux-2.6/fs/fcntl.c 2010-05-14 18:23:06.000000000 +0200 @@ -14,6 +14,7 @@ #include <linux/dnotify.h> #include <linux/slab.h> #include <linux/module.h> +#include <linux/pipe_fs_i.h> #include <linux/security.h> #include <linux/ptrace.h> #include <linux/signal.h> @@ -412,6 +413,10 @@ static long do_fcntl(int fd, unsigned in case F_NOTIFY: err = fcntl_dirnotify(fd, filp, arg); break; + case F_SETPIPE_SZ: + case F_GETPIPE_SZ: + err = pipe_fcntl(filp, cmd, arg); + break; default: break; } Index: linux-2.6/fs/pipe.c =================================================================== --- linux-2.6.orig/fs/pipe.c 2010-05-14 18:23:05.000000000 +0200 +++ linux-2.6/fs/pipe.c 2010-05-14 18:23:06.000000000 +0200 @@ -11,6 +11,7 @@ #include <linux/module.h> #include <linux/init.h> #include <linux/fs.h> +#include <linux/log2.h> #include <linux/mount.h> #include <linux/pipe_fs_i.h> #include <linux/uio.h> @@ -390,7 +391,7 @@ redo: if (!buf->len) { buf->ops = NULL; ops->release(pipe, buf); - curbuf = (curbuf + 1) & (PIPE_BUFFERS-1); + curbuf = (curbuf + 1) & (pipe->buffers - 1); pipe->curbuf = curbuf; pipe->nrbufs = --bufs; do_wakeup = 1; @@ -472,7 +473,7 @@ pipe_write(struct kiocb *iocb, const str chars = total_len & (PAGE_SIZE-1); /* size of the last buffer */ if (pipe->nrbufs && chars != 0) { int lastbuf = (pipe->curbuf + pipe->nrbufs - 1) & - (PIPE_BUFFERS-1); + (pipe->buffers - 1); struct pipe_buffer *buf = pipe->bufs + lastbuf; const struct pipe_buf_operations *ops = buf->ops; int offset = buf->offset + buf->len; @@ -518,8 +519,8 @@ redo1: break; } bufs = pipe->nrbufs; - if (bufs < PIPE_BUFFERS) { - int newbuf = (pipe->curbuf + bufs) & (PIPE_BUFFERS-1); + if (bufs < pipe->buffers) { + int newbuf = (pipe->curbuf + bufs) & (pipe->buffers-1); struct pipe_buffer *buf = pipe->bufs + newbuf; struct page *page = pipe->tmp_page; char *src; @@ -580,7 +581,7 @@ redo2: if (!total_len) break; } - if (bufs < PIPE_BUFFERS) + if (bufs < pipe->buffers) continue; if (filp->f_flags & O_NONBLOCK) { if (!ret) @@ -640,7 +641,7 @@ static long pipe_ioctl(struct file *filp nrbufs = pipe->nrbufs; while (--nrbufs >= 0) { count += pipe->bufs[buf].len; - buf = (buf+1) & (PIPE_BUFFERS-1); + buf = (buf+1) & (pipe->buffers - 1); } mutex_unlock(&inode->i_mutex); @@ -671,7 +672,7 @@ pipe_poll(struct file *filp, poll_table } if (filp->f_mode & FMODE_WRITE) { - mask |= (nrbufs < PIPE_BUFFERS) ? POLLOUT | POLLWRNORM : 0; + mask |= (nrbufs < pipe->buffers) ? POLLOUT | POLLWRNORM : 0; /* * Most Unices do not set POLLERR for FIFOs but on Linux they * behave exactly like pipes for poll(). @@ -877,25 +878,32 @@ struct pipe_inode_info * alloc_pipe_info pipe = kzalloc(sizeof(struct pipe_inode_info), GFP_KERNEL); if (pipe) { - init_waitqueue_head(&pipe->wait); - pipe->r_counter = pipe->w_counter = 1; - pipe->inode = inode; + pipe->bufs = kzalloc(sizeof(struct pipe_buffer) * PIPE_DEF_BUFFERS, GFP_KERNEL); + if (pipe->bufs) { + init_waitqueue_head(&pipe->wait); + pipe->r_counter = pipe->w_counter = 1; + pipe->inode = inode; + pipe->buffers = PIPE_DEF_BUFFERS; + return pipe; + } + kfree(pipe); } - return pipe; + return NULL; } void __free_pipe_info(struct pipe_inode_info *pipe) { int i; - for (i = 0; i < PIPE_BUFFERS; i++) { + for (i = 0; i < pipe->buffers; i++) { struct pipe_buffer *buf = pipe->bufs + i; if (buf->ops) buf->ops->release(pipe, buf); } if (pipe->tmp_page) __free_page(pipe->tmp_page); + kfree(pipe->bufs); kfree(pipe); } @@ -1094,6 +1102,81 @@ SYSCALL_DEFINE1(pipe, int __user *, fild } /* + * Allocate a new array of pipe buffers and copy the info over. Returns the + * pipe size if successful, or return -ERROR on error. + */ +static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long arg) +{ + struct pipe_buffer *bufs; + + /* + * Must be a power-of-2 currently + */ + if (!is_power_of_2(arg)) + return -EINVAL; + + /* + * We can shrink the pipe, if arg >= pipe->nrbufs. Since we don't + * expect a lot of shrink+grow operations, just free and allocate + * again like we would do for growing. If the pipe currently + * contains more buffers than arg, then return busy. + */ + if (arg < pipe->nrbufs) + return -EBUSY; + + bufs = kcalloc(arg, sizeof(struct pipe_buffer), GFP_KERNEL); + if (unlikely(!bufs)) + return -ENOMEM; + + /* + * The pipe array wraps around, so just start the new one at zero + * and adjust the indexes. + */ + if (pipe->nrbufs) { + const unsigned int tail = pipe->nrbufs & (pipe->buffers - 1); + const unsigned int head = pipe->nrbufs - tail; + + if (head) + memcpy(bufs, pipe->bufs + pipe->curbuf, head * sizeof(struct pipe_buffer)); + if (tail) + memcpy(bufs + head, pipe->bufs + pipe->curbuf, tail * sizeof(struct pipe_buffer)); + } + + pipe->curbuf = 0; + kfree(pipe->bufs); + pipe->bufs = bufs; + pipe->buffers = arg; + return arg; +} + +long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct pipe_inode_info *pipe; + long ret; + + pipe = file->f_path.dentry->d_inode->i_pipe; + if (!pipe) + return -EBADF; + + mutex_lock(&pipe->inode->i_mutex); + + switch (cmd) { + case F_SETPIPE_SZ: + ret = pipe_set_size(pipe, arg); + break; + case F_GETPIPE_SZ: + ret = pipe->buffers; + break; + default: + ret = -EINVAL; + break; + } + + mutex_unlock(&pipe->inode->i_mutex); + return ret; +} + +/* * pipefs should _never_ be mounted by userland - too much of security hassle, * no real gain from having the whole whorehouse mounted. So we don't need * any operations on the root directory. However, we need a non-trivial Index: linux-2.6/fs/splice.c =================================================================== --- linux-2.6.orig/fs/splice.c 2010-05-14 18:23:05.000000000 +0200 +++ linux-2.6/fs/splice.c 2010-05-14 18:23:06.000000000 +0200 @@ -193,8 +193,8 @@ ssize_t splice_to_pipe(struct pipe_inode break; } - if (pipe->nrbufs < PIPE_BUFFERS) { - int newbuf = (pipe->curbuf + pipe->nrbufs) & (PIPE_BUFFERS - 1); + if (pipe->nrbufs < pipe->buffers) { + int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); struct pipe_buffer *buf = pipe->bufs + newbuf; buf->page = spd->pages[page_nr]; @@ -214,7 +214,7 @@ ssize_t splice_to_pipe(struct pipe_inode if (!--spd->nr_pages) break; - if (pipe->nrbufs < PIPE_BUFFERS) + if (pipe->nrbufs < pipe->buffers) continue; break; @@ -265,6 +265,36 @@ static void spd_release_page(struct spli page_cache_release(spd->pages[i]); } +/* + * Check if we need to grow the arrays holding pages and partial page + * descriptions. + */ +int splice_grow_spd(struct pipe_inode_info *pipe, struct splice_pipe_desc *spd) +{ + if (pipe->buffers <= PIPE_DEF_BUFFERS) + return 0; + + spd->pages = kmalloc(pipe->buffers * sizeof(struct page *), GFP_KERNEL); + spd->partial = kmalloc(pipe->buffers * sizeof(struct partial_page), GFP_KERNEL); + + if (spd->pages && spd->partial) + return 0; + + kfree(spd->pages); + kfree(spd->partial); + return -ENOMEM; +} + +void splice_shrink_spd(struct pipe_inode_info *pipe, + struct splice_pipe_desc *spd) +{ + if (pipe->buffers <= PIPE_DEF_BUFFERS) + return; + + kfree(spd->pages); + kfree(spd->partial); +} + static int __generic_file_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, @@ -272,29 +302,32 @@ __generic_file_splice_read(struct file * { struct address_space *mapping = in->f_mapping; unsigned int loff, nr_pages, req_pages; - struct page *pages[PIPE_BUFFERS]; - struct partial_page partial[PIPE_BUFFERS]; + struct page *pages_def[PIPE_DEF_BUFFERS]; + struct partial_page partial_def[PIPE_DEF_BUFFERS]; struct page *page; pgoff_t index, end_index; loff_t isize; int error, page_nr; struct splice_pipe_desc spd = { - .pages = pages, - .partial = partial, + .pages = pages_def, + .partial = partial_def, .flags = flags, .ops = &page_cache_pipe_buf_ops, .spd_release = spd_release_page, }; + if (splice_grow_spd(pipe, &spd)) + return -ENOMEM; + index = *ppos >> PAGE_CACHE_SHIFT; loff = *ppos & ~PAGE_CACHE_MASK; req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; - nr_pages = min(req_pages, (unsigned)PIPE_BUFFERS); + nr_pages = min(req_pages, pipe->buffers); /* * Lookup the (hopefully) full range of pages we need. */ - spd.nr_pages = find_get_pages_contig(mapping, index, nr_pages, pages); + spd.nr_pages = find_get_pages_contig(mapping, index, nr_pages, spd.pages); index += spd.nr_pages; /* @@ -335,7 +368,7 @@ __generic_file_splice_read(struct file * unlock_page(page); } - pages[spd.nr_pages++] = page; + spd.pages[spd.nr_pages++] = page; index++; } @@ -356,7 +389,7 @@ __generic_file_splice_read(struct file * * this_len is the max we'll use from this page */ this_len = min_t(unsigned long, len, PAGE_CACHE_SIZE - loff); - page = pages[page_nr]; + page = spd.pages[page_nr]; if (PageReadahead(page)) page_cache_async_readahead(mapping, &in->f_ra, in, @@ -393,8 +426,8 @@ __generic_file_splice_read(struct file * error = -ENOMEM; break; } - page_cache_release(pages[page_nr]); - pages[page_nr] = page; + page_cache_release(spd.pages[page_nr]); + spd.pages[page_nr] = page; } /* * page was already under io and is now done, great @@ -451,8 +484,8 @@ fill_it: len = this_len; } - partial[page_nr].offset = loff; - partial[page_nr].len = this_len; + spd.partial[page_nr].offset = loff; + spd.partial[page_nr].len = this_len; len -= this_len; loff = 0; spd.nr_pages++; @@ -464,12 +497,13 @@ fill_it: * we got, 'nr_pages' is how many pages are in the map. */ while (page_nr < nr_pages) - page_cache_release(pages[page_nr++]); + page_cache_release(spd.pages[page_nr++]); in->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT; if (spd.nr_pages) - return splice_to_pipe(pipe, &spd); + error = splice_to_pipe(pipe, &spd); + splice_shrink_spd(pipe, &spd); return error; } @@ -560,27 +594,36 @@ ssize_t default_file_splice_read(struct unsigned int nr_pages; unsigned int nr_freed; size_t offset; - struct page *pages[PIPE_BUFFERS]; - struct partial_page partial[PIPE_BUFFERS]; - struct iovec vec[PIPE_BUFFERS]; + struct page *pages_def[PIPE_DEF_BUFFERS]; + struct partial_page partial_def[PIPE_DEF_BUFFERS]; + struct iovec *vec; pgoff_t index; ssize_t res; size_t this_len; int error; int i; struct splice_pipe_desc spd = { - .pages = pages, - .partial = partial, + .pages = pages_def, + .partial = partial_def, .flags = flags, .ops = &default_pipe_buf_ops, .spd_release = spd_release_page, }; + if (splice_grow_spd(pipe, &spd)) + return -ENOMEM; + + vec = kmalloc(pipe->buffers * sizeof(struct iovec), GFP_KERNEL); + if (!vec) { + res = -ENOMEM; + goto out; + } + index = *ppos >> PAGE_CACHE_SHIFT; offset = *ppos & ~PAGE_CACHE_MASK; nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; - for (i = 0; i < nr_pages && i < PIPE_BUFFERS && len; i++) { + for (i = 0; i < nr_pages && i < pipe->buffers && len; i++) { struct page *page; page = alloc_page(GFP_USER); @@ -591,7 +634,7 @@ ssize_t default_file_splice_read(struct this_len = min_t(size_t, len, PAGE_CACHE_SIZE - offset); vec[i].iov_base = (void __user *) page_address(page); vec[i].iov_len = this_len; - pages[i] = page; + spd.pages[i] = page; spd.nr_pages++; len -= this_len; offset = 0; @@ -610,11 +653,11 @@ ssize_t default_file_splice_read(struct nr_freed = 0; for (i = 0; i < spd.nr_pages; i++) { this_len = min_t(size_t, vec[i].iov_len, res); - partial[i].offset = 0; - partial[i].len = this_len; + spd.partial[i].offset = 0; + spd.partial[i].len = this_len; if (!this_len) { - __free_page(pages[i]); - pages[i] = NULL; + __free_page(spd.pages[i]); + spd.pages[i] = NULL; nr_freed++; } res -= this_len; @@ -625,13 +668,17 @@ ssize_t default_file_splice_read(struct if (res > 0) *ppos += res; +out: + splice_shrink_spd(pipe, &spd); + kfree(vec); return res; err: for (i = 0; i < spd.nr_pages; i++) - __free_page(pages[i]); + __free_page(spd.pages[i]); - return error; + res = error; + goto out; } EXPORT_SYMBOL(default_file_splice_read); @@ -784,7 +831,7 @@ int splice_from_pipe_feed(struct pipe_in if (!buf->len) { buf->ops = NULL; ops->release(pipe, buf); - pipe->curbuf = (pipe->curbuf + 1) & (PIPE_BUFFERS - 1); + pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1); pipe->nrbufs--; if (pipe->inode) sd->need_wakeup = true; @@ -1211,7 +1258,7 @@ out_release: * If we did an incomplete transfer we must release * the pipe buffers in question: */ - for (i = 0; i < PIPE_BUFFERS; i++) { + for (i = 0; i < pipe->buffers; i++) { struct pipe_buffer *buf = pipe->bufs + i; if (buf->ops) { @@ -1371,7 +1418,8 @@ static long do_splice(struct file *in, l */ static int get_iovec_page_array(const struct iovec __user *iov, unsigned int nr_vecs, struct page **pages, - struct partial_page *partial, int aligned) + struct partial_page *partial, int aligned, + unsigned int pipe_buffers) { int buffers = 0, error = 0; @@ -1414,8 +1462,8 @@ static int get_iovec_page_array(const st break; npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT; - if (npages > PIPE_BUFFERS - buffers) - npages = PIPE_BUFFERS - buffers; + if (npages > pipe_buffers - buffers) + npages = pipe_buffers - buffers; error = get_user_pages_fast((unsigned long)base, npages, 0, &pages[buffers]); @@ -1450,7 +1498,7 @@ static int get_iovec_page_array(const st * or if we mapped the max number of pages that we have * room for. */ - if (error < npages || buffers == PIPE_BUFFERS) + if (error < npages || buffers == pipe_buffers) break; nr_vecs--; @@ -1593,26 +1641,34 @@ static long vmsplice_to_pipe(struct file unsigned long nr_segs, unsigned int flags) { struct pipe_inode_info *pipe; - struct page *pages[PIPE_BUFFERS]; - struct partial_page partial[PIPE_BUFFERS]; + struct page *pages_def[PIPE_DEF_BUFFERS]; + struct partial_page partial_def[PIPE_DEF_BUFFERS]; struct splice_pipe_desc spd = { - .pages = pages, - .partial = partial, + .pages = pages_def, + .partial = partial_def, .flags = flags, .ops = &user_page_pipe_buf_ops, .spd_release = spd_release_page, }; + long ret; pipe = pipe_info(file->f_path.dentry->d_inode); if (!pipe) return -EBADF; - spd.nr_pages = get_iovec_page_array(iov, nr_segs, pages, partial, - flags & SPLICE_F_GIFT); + if (splice_grow_spd(pipe, &spd)) + return -ENOMEM; + + spd.nr_pages = get_iovec_page_array(iov, nr_segs, spd.pages, + spd.partial, flags & SPLICE_F_GIFT, + pipe->buffers); if (spd.nr_pages <= 0) - return spd.nr_pages; + ret = spd.nr_pages; + else + ret = splice_to_pipe(pipe, &spd); - return splice_to_pipe(pipe, &spd); + splice_shrink_spd(pipe, &spd); + return ret; } /* @@ -1738,13 +1794,13 @@ static int opipe_prep(struct pipe_inode_ * Check ->nrbufs without the inode lock first. This function * is speculative anyways, so missing one is ok. */ - if (pipe->nrbufs < PIPE_BUFFERS) + if (pipe->nrbufs < pipe->buffers) return 0; ret = 0; pipe_lock(pipe); - while (pipe->nrbufs >= PIPE_BUFFERS) { + while (pipe->nrbufs >= pipe->buffers) { if (!pipe->readers) { send_sig(SIGPIPE, current, 0); ret = -EPIPE; @@ -1810,7 +1866,7 @@ retry: * Cannot make any progress, because either the input * pipe is empty or the output pipe is full. */ - if (!ipipe->nrbufs || opipe->nrbufs >= PIPE_BUFFERS) { + if (!ipipe->nrbufs || opipe->nrbufs >= opipe->buffers) { /* Already processed some buffers, break */ if (ret) break; @@ -1831,7 +1887,7 @@ retry: } ibuf = ipipe->bufs + ipipe->curbuf; - nbuf = (opipe->curbuf + opipe->nrbufs) % PIPE_BUFFERS; + nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1); obuf = opipe->bufs + nbuf; if (len >= ibuf->len) { @@ -1841,7 +1897,7 @@ retry: *obuf = *ibuf; ibuf->ops = NULL; opipe->nrbufs++; - ipipe->curbuf = (ipipe->curbuf + 1) % PIPE_BUFFERS; + ipipe->curbuf = (ipipe->curbuf + 1) & (ipipe->buffers - 1); ipipe->nrbufs--; input_wakeup = true; } else { @@ -1914,11 +1970,11 @@ static int link_pipe(struct pipe_inode_i * If we have iterated all input buffers or ran out of * output room, break. */ - if (i >= ipipe->nrbufs || opipe->nrbufs >= PIPE_BUFFERS) + if (i >= ipipe->nrbufs || opipe->nrbufs >= opipe->buffers) break; - ibuf = ipipe->bufs + ((ipipe->curbuf + i) & (PIPE_BUFFERS - 1)); - nbuf = (opipe->curbuf + opipe->nrbufs) & (PIPE_BUFFERS - 1); + ibuf = ipipe->bufs + ((ipipe->curbuf + i) & (ipipe->buffers-1)); + nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1); /* * Get a reference to this pipe buffer, Index: linux-2.6/include/asm-generic/fcntl.h =================================================================== --- linux-2.6.orig/include/asm-generic/fcntl.h 2010-05-14 18:23:05.000000000 +0200 +++ linux-2.6/include/asm-generic/fcntl.h 2010-05-14 18:23:06.000000000 +0200 @@ -104,6 +104,13 @@ #define F_GETOWN_EX 16 #endif +#ifndef F_SETPIPE_SZ /* for growing pipe sizes */ +#define F_SETPIPE_SZ 17 +#endif +#ifndef F_GETPIPE_SZ +#define F_GETPIPE_SZ 18 +#endif + #define F_OWNER_TID 0 #define F_OWNER_PID 1 #define F_OWNER_PGRP 2 Index: linux-2.6/include/linux/pipe_fs_i.h =================================================================== --- linux-2.6.orig/include/linux/pipe_fs_i.h 2010-05-14 18:23:05.000000000 +0200 +++ linux-2.6/include/linux/pipe_fs_i.h 2010-05-14 18:23:06.000000000 +0200 @@ -3,7 +3,7 @@ #define PIPEFS_MAGIC 0x50495045 -#define PIPE_BUFFERS (16) +#define PIPE_DEF_BUFFERS 16 #define PIPE_BUF_FLAG_LRU 0x01 /* page is on the LRU */ #define PIPE_BUF_FLAG_ATOMIC 0x02 /* was atomically mapped */ @@ -44,17 +44,17 @@ struct pipe_buffer { **/ struct pipe_inode_info { wait_queue_head_t wait; - unsigned int nrbufs, curbuf; - struct page *tmp_page; + unsigned int nrbufs, curbuf, buffers; unsigned int readers; unsigned int writers; unsigned int waiting_writers; unsigned int r_counter; unsigned int w_counter; + struct page *tmp_page; struct fasync_struct *fasync_readers; struct fasync_struct *fasync_writers; struct inode *inode; - struct pipe_buffer bufs[PIPE_BUFFERS]; + struct pipe_buffer *bufs; }; /* @@ -154,4 +154,7 @@ int generic_pipe_buf_confirm(struct pipe int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *); void generic_pipe_buf_release(struct pipe_inode_info *, struct pipe_buffer *); +/* for F_SETPIPE_SZ and F_GETPIPE_SZ */ +long pipe_fcntl(struct file *, unsigned int, unsigned long arg); + #endif Index: linux-2.6/include/linux/splice.h =================================================================== --- linux-2.6.orig/include/linux/splice.h 2010-05-14 18:23:05.000000000 +0200 +++ linux-2.6/include/linux/splice.h 2010-05-14 18:23:06.000000000 +0200 @@ -82,4 +82,11 @@ extern ssize_t splice_to_pipe(struct pip extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *, splice_direct_actor *); +/* + * for dynamic pipe sizing + */ +extern int splice_grow_spd(struct pipe_inode_info *, struct splice_pipe_desc *); +extern void splice_shrink_spd(struct pipe_inode_info *, + struct splice_pipe_desc *); + #endif Index: linux-2.6/kernel/relay.c =================================================================== --- linux-2.6.orig/kernel/relay.c 2010-05-14 18:23:05.000000000 +0200 +++ linux-2.6/kernel/relay.c 2010-05-14 18:23:06.000000000 +0200 @@ -1231,12 +1231,12 @@ static ssize_t subbuf_splice_actor(struc size_t read_subbuf = read_start / subbuf_size; size_t padding = rbuf->padding[read_subbuf]; size_t nonpad_end = read_subbuf * subbuf_size + subbuf_size - padding; - struct page *pages[PIPE_BUFFERS]; - struct partial_page partial[PIPE_BUFFERS]; + struct page *pages_def[PIPE_DEF_BUFFERS]; + struct partial_page partial_def[PIPE_DEF_BUFFERS]; struct splice_pipe_desc spd = { - .pages = pages, + .pages = pages_def, .nr_pages = 0, - .partial = partial, + .partial = partial_def, .flags = flags, .ops = &relay_pipe_buf_ops, .spd_release = relay_page_release, @@ -1245,6 +1245,8 @@ static ssize_t subbuf_splice_actor(struc if (rbuf->subbufs_produced == rbuf->subbufs_consumed) return 0; + if (splice_grow_spd(pipe, &spd)) + return -ENOMEM; /* * Adjust read len, if longer than what is available @@ -1255,7 +1257,7 @@ static ssize_t subbuf_splice_actor(struc subbuf_pages = rbuf->chan->alloc_size >> PAGE_SHIFT; pidx = (read_start / PAGE_SIZE) % subbuf_pages; poff = read_start & ~PAGE_MASK; - nr_pages = min_t(unsigned int, subbuf_pages, PIPE_BUFFERS); + nr_pages = min_t(unsigned int, subbuf_pages, pipe->buffers); for (total_len = 0; spd.nr_pages < nr_pages; spd.nr_pages++) { unsigned int this_len, this_end, private; @@ -1289,16 +1291,19 @@ static ssize_t subbuf_splice_actor(struc } } + ret = 0; if (!spd.nr_pages) - return 0; + goto out; ret = *nonpad_ret = splice_to_pipe(pipe, &spd); if (ret < 0 || ret < total_len) - return ret; + goto out; if (read_start + ret == nonpad_end) ret += padding; +out: + splice_shrink_spd(pipe, &spd); return ret; } Index: linux-2.6/net/core/skbuff.c =================================================================== --- linux-2.6.orig/net/core/skbuff.c 2010-05-14 18:23:05.000000000 +0200 +++ linux-2.6/net/core/skbuff.c 2010-05-14 18:23:06.000000000 +0200 @@ -1417,12 +1417,13 @@ new_page: /* * Fill page/offset/length into spd, if it can hold more pages. */ -static inline int spd_fill_page(struct splice_pipe_desc *spd, struct page *page, +static inline int spd_fill_page(struct splice_pipe_desc *spd, + struct pipe_inode_info *pipe, struct page *page, unsigned int *len, unsigned int offset, struct sk_buff *skb, int linear, struct sock *sk) { - if (unlikely(spd->nr_pages == PIPE_BUFFERS)) + if (unlikely(spd->nr_pages == pipe->buffers)) return 1; if (linear) { @@ -1457,8 +1458,9 @@ static inline void __segment_seek(struct static inline int __splice_segment(struct page *page, unsigned int poff, unsigned int plen, unsigned int *off, unsigned int *len, struct sk_buff *skb, - struct splice_pipe_desc *spd, int linear, - struct sock *sk) + struct splice_pipe_desc *spd, + struct pipe_inode_info *pipe, + int linear, struct sock *sk) { if (!*len) return 1; @@ -1481,7 +1483,7 @@ static inline int __splice_segment(struc /* the linear region may spread across several pages */ flen = min_t(unsigned int, flen, PAGE_SIZE - poff); - if (spd_fill_page(spd, page, &flen, poff, skb, linear, sk)) + if (spd_fill_page(spd, pipe, page, &flen, poff, skb, linear, sk)) return 1; __segment_seek(&page, &poff, &plen, flen); @@ -1498,7 +1500,7 @@ static inline int __splice_segment(struc */ static int __skb_splice_bits(struct sk_buff *skb, unsigned int *offset, unsigned int *len, struct splice_pipe_desc *spd, - struct sock *sk) + struct pipe_inode_info *pipe, struct sock *sk) { int seg; @@ -1508,7 +1510,7 @@ static int __skb_splice_bits(struct sk_b if (__splice_segment(virt_to_page(skb->data), (unsigned long) skb->data & (PAGE_SIZE - 1), skb_headlen(skb), - offset, len, skb, spd, 1, sk)) + offset, len, skb, spd, pipe, 1, sk)) return 1; /* @@ -1518,7 +1520,7 @@ static int __skb_splice_bits(struct sk_b const skb_frag_t *f = &skb_shinfo(skb)->frags[seg]; if (__splice_segment(f->page, f->page_offset, f->size, - offset, len, skb, spd, 0, sk)) + offset, len, skb, spd, pipe, 0, sk)) return 1; } @@ -1535,23 +1537,27 @@ int skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe, unsigned int tlen, unsigned int flags) { - struct partial_page partial[PIPE_BUFFERS]; - struct page *pages[PIPE_BUFFERS]; + struct partial_page partial_def[PIPE_DEF_BUFFERS]; + struct page *pages_def[PIPE_DEF_BUFFERS]; struct splice_pipe_desc spd = { - .pages = pages, - .partial = partial, + .pages = pages_def, + .partial = partial_def, .flags = flags, .ops = &sock_pipe_buf_ops, .spd_release = sock_spd_release, }; struct sk_buff *frag_iter; struct sock *sk = skb->sk; + int ret = 0; + + if (splice_grow_spd(pipe, &spd)) + return -ENOMEM; /* * __skb_splice_bits() only fails if the output has no room left, * so no point in going over the frag_list for the error case. */ - if (__skb_splice_bits(skb, &offset, &tlen, &spd, sk)) + if (__skb_splice_bits(skb, &offset, &tlen, &spd, pipe, sk)) goto done; else if (!tlen) goto done; @@ -1562,13 +1568,12 @@ int skb_splice_bits(struct sk_buff *skb, skb_walk_frags(skb, frag_iter) { if (!tlen) break; - if (__skb_splice_bits(frag_iter, &offset, &tlen, &spd, sk)) + if (__skb_splice_bits(frag_iter, &offset, &tlen, &spd, pipe, sk)) break; } done: if (spd.nr_pages) { - int ret; /* * Drop the socket lock, otherwise we have reverse @@ -1582,10 +1587,10 @@ done: release_sock(sk); ret = splice_to_pipe(pipe, &spd); lock_sock(sk); - return ret; } - return 0; + splice_shrink_spd(pipe, &spd); + return ret; } /** Index: linux-2.6/kernel/trace/trace.c =================================================================== --- linux-2.6.orig/kernel/trace/trace.c 2010-05-12 11:19:25.000000000 +0200 +++ linux-2.6/kernel/trace/trace.c 2010-05-14 18:27:42.000000000 +0200 @@ -3269,12 +3269,12 @@ static ssize_t tracing_splice_read_pipe( size_t len, unsigned int flags) { - struct page *pages[PIPE_BUFFERS]; - struct partial_page partial[PIPE_BUFFERS]; + struct page *pages_def[PIPE_DEF_BUFFERS]; + struct partial_page partial_def[PIPE_DEF_BUFFERS]; struct trace_iterator *iter = filp->private_data; struct splice_pipe_desc spd = { - .pages = pages, - .partial = partial, + .pages = pages_def, + .partial = partial_def, .nr_pages = 0, /* This gets updated below. */ .flags = flags, .ops = &tracing_pipe_buf_ops, @@ -3285,6 +3285,9 @@ static ssize_t tracing_splice_read_pipe( size_t rem; unsigned int i; + if (splice_grow_spd(pipe, &spd)) + return -ENOMEM; + /* copy the tracer to avoid using a global lock all around */ mutex_lock(&trace_types_lock); if (unlikely(old_tracer != current_trace && current_trace)) { @@ -3315,23 +3318,23 @@ static ssize_t tracing_splice_read_pipe( trace_access_lock(iter->cpu_file); /* Fill as many pages as possible. */ - for (i = 0, rem = len; i < PIPE_BUFFERS && rem; i++) { - pages[i] = alloc_page(GFP_KERNEL); - if (!pages[i]) + for (i = 0, rem = len; i < pipe->buffers && rem; i++) { + spd.pages[i] = alloc_page(GFP_KERNEL); + if (!spd.pages[i]) break; rem = tracing_fill_pipe_page(rem, iter); /* Copy the data into the page, so we can start over. */ ret = trace_seq_to_buffer(&iter->seq, - page_address(pages[i]), + page_address(spd.pages[i]), iter->seq.len); if (ret < 0) { - __free_page(pages[i]); + __free_page(spd.pages[i]); break; } - partial[i].offset = 0; - partial[i].len = iter->seq.len; + spd.partial[i].offset = 0; + spd.partial[i].len = iter->seq.len; trace_seq_init(&iter->seq); } @@ -3342,12 +3345,14 @@ static ssize_t tracing_splice_read_pipe( spd.nr_pages = i; - return splice_to_pipe(pipe, &spd); + ret = splice_to_pipe(pipe, &spd); +out: + splice_shrink_spd(pipe, &spd); + return ret; out_err: mutex_unlock(&iter->mutex); - - return ret; + goto out; } static ssize_t @@ -3746,11 +3751,11 @@ tracing_buffers_splice_read(struct file unsigned int flags) { struct ftrace_buffer_info *info = file->private_data; - struct partial_page partial[PIPE_BUFFERS]; - struct page *pages[PIPE_BUFFERS]; + struct partial_page partial_def[PIPE_DEF_BUFFERS]; + struct page *pages_def[PIPE_DEF_BUFFERS]; struct splice_pipe_desc spd = { - .pages = pages, - .partial = partial, + .pages = pages_def, + .partial = partial_def, .flags = flags, .ops = &buffer_pipe_buf_ops, .spd_release = buffer_spd_release, @@ -3759,22 +3764,28 @@ tracing_buffers_splice_read(struct file int entries, size, i; size_t ret; + if (splice_grow_spd(pipe, &spd)) + return -ENOMEM; + if (*ppos & (PAGE_SIZE - 1)) { WARN_ONCE(1, "Ftrace: previous read must page-align\n"); - return -EINVAL; + ret = -EINVAL; + goto out; } if (len & (PAGE_SIZE - 1)) { WARN_ONCE(1, "Ftrace: splice_read should page-align\n"); - if (len < PAGE_SIZE) - return -EINVAL; + if (len < PAGE_SIZE) { + ret = -EINVAL; + goto out; + } len &= PAGE_MASK; } trace_access_lock(info->cpu); entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu); - for (i = 0; i < PIPE_BUFFERS && len && entries; i++, len -= PAGE_SIZE) { + for (i = 0; i < pipe->buffers && len && entries; i++, len -= PAGE_SIZE) { struct page *page; int r; @@ -3829,11 +3840,12 @@ tracing_buffers_splice_read(struct file else ret = 0; /* TODO: block */ - return ret; + goto out; } ret = splice_to_pipe(pipe, &spd); - + splice_shrink_spd(pipe, &spd); +out: return ret; } -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
