From cbb7e577e732f576b9f399bc2600bdc0626c68dc Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 11 Apr 2006 14:57:50 +0200 Subject: [PATCH] splice: pass offset around for ->splice_read() and ->splice_write() We need not use ->f_pos as the offset for the file input/output. If the user passed an offset pointer in through sys_splice(), just use that and leave ->f_pos alone. Signed-off-by: Jens Axboe --- fs/splice.c | 86 ++++++++++++++++++++++---------------------- fs/xfs/linux-2.6/xfs_file.c | 12 ++++--- fs/xfs/linux-2.6/xfs_lrw.c | 14 ++++---- fs/xfs/linux-2.6/xfs_lrw.h | 4 +-- fs/xfs/linux-2.6/xfs_vnode.h | 12 +++---- 5 files changed, 68 insertions(+), 60 deletions(-) (limited to 'fs') diff --git a/fs/splice.c b/fs/splice.c index e50a460..5d3eda6 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -231,8 +231,9 @@ static ssize_t move_to_pipe(struct pipe_inode_info *pipe, struct page **pages, } static int -__generic_file_splice_read(struct file *in, struct pipe_inode_info *pipe, - size_t len, unsigned int flags) +__generic_file_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags) { struct address_space *mapping = in->f_mapping; unsigned int offset, nr_pages; @@ -241,8 +242,8 @@ __generic_file_splice_read(struct file *in, struct pipe_inode_info *pipe, pgoff_t index; int i, error; - index = in->f_pos >> PAGE_CACHE_SHIFT; - offset = in->f_pos & ~PAGE_CACHE_MASK; + index = *ppos >> PAGE_CACHE_SHIFT; + offset = *ppos & ~PAGE_CACHE_MASK; nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; if (nr_pages > PIPE_BUFFERS) @@ -348,8 +349,9 @@ fill_it: * * Will read pages from given file and fill them into a pipe. */ -ssize_t generic_file_splice_read(struct file *in, struct pipe_inode_info *pipe, - size_t len, unsigned int flags) +ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags) { ssize_t spliced; int ret; @@ -358,12 +360,12 @@ ssize_t generic_file_splice_read(struct file *in, struct pipe_inode_info *pipe, spliced = 0; while (len) { - ret = __generic_file_splice_read(in, pipe, len, flags); + ret = __generic_file_splice_read(in, ppos, pipe, len, flags); if (ret <= 0) break; - in->f_pos += ret; + *ppos += ret; len -= ret; spliced += ret; @@ -561,7 +563,7 @@ typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *, * to the wanted destination. See pipe_to_file/pipe_to_sendpage above. */ static ssize_t move_from_pipe(struct pipe_inode_info *pipe, struct file *out, - size_t len, unsigned int flags, + loff_t *ppos, size_t len, unsigned int flags, splice_actor *actor) { int ret, do_wakeup, err; @@ -573,7 +575,7 @@ static ssize_t move_from_pipe(struct pipe_inode_info *pipe, struct file *out, sd.total_len = len; sd.flags = flags; sd.file = out; - sd.pos = out->f_pos; + sd.pos = *ppos; if (pipe->inode) mutex_lock(&pipe->inode->i_mutex); @@ -656,9 +658,7 @@ static ssize_t move_from_pipe(struct pipe_inode_info *pipe, struct file *out, kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); } - out->f_pos = sd.pos; return ret; - } /** @@ -674,12 +674,12 @@ static ssize_t move_from_pipe(struct pipe_inode_info *pipe, struct file *out, */ ssize_t generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out, - size_t len, unsigned int flags) + loff_t *ppos, size_t len, unsigned int flags) { struct address_space *mapping = out->f_mapping; ssize_t ret; - ret = move_from_pipe(pipe, out, len, flags, pipe_to_file); + ret = move_from_pipe(pipe, out, ppos, len, flags, pipe_to_file); /* * If file or inode is SYNC and we actually wrote some data, sync it. @@ -715,9 +715,9 @@ EXPORT_SYMBOL(generic_file_splice_write); * */ ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, struct file *out, - size_t len, unsigned int flags) + loff_t *ppos, size_t len, unsigned int flags) { - return move_from_pipe(pipe, out, len, flags, pipe_to_sendpage); + return move_from_pipe(pipe, out, ppos, len, flags, pipe_to_sendpage); } EXPORT_SYMBOL(generic_splice_sendpage); @@ -726,9 +726,8 @@ EXPORT_SYMBOL(generic_splice_sendpage); * Attempt to initiate a splice from pipe to file. */ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out, - size_t len, unsigned int flags) + loff_t *ppos, size_t len, unsigned int flags) { - loff_t pos; int ret; if (unlikely(!out->f_op || !out->f_op->splice_write)) @@ -737,22 +736,21 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out, if (unlikely(!(out->f_mode & FMODE_WRITE))) return -EBADF; - pos = out->f_pos; - - ret = rw_verify_area(WRITE, out, &pos, len); + ret = rw_verify_area(WRITE, out, ppos, len); if (unlikely(ret < 0)) return ret; - return out->f_op->splice_write(pipe, out, len, flags); + return out->f_op->splice_write(pipe, out, ppos, len, flags); } /* * Attempt to initiate a splice from a file to a pipe. */ -static long do_splice_to(struct file *in, struct pipe_inode_info *pipe, - size_t len, unsigned int flags) +static long do_splice_to(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags) { - loff_t pos, isize, left; + loff_t isize, left; int ret; if (unlikely(!in->f_op || !in->f_op->splice_read)) @@ -761,28 +759,27 @@ static long do_splice_to(struct file *in, struct pipe_inode_info *pipe, if (unlikely(!(in->f_mode & FMODE_READ))) return -EBADF; - pos = in->f_pos; - - ret = rw_verify_area(READ, in, &pos, len); + ret = rw_verify_area(READ, in, ppos, len); if (unlikely(ret < 0)) return ret; isize = i_size_read(in->f_mapping->host); - if (unlikely(in->f_pos >= isize)) + if (unlikely(*ppos >= isize)) return 0; - left = isize - in->f_pos; + left = isize - *ppos; if (unlikely(left < len)) len = left; - return in->f_op->splice_read(in, pipe, len, flags); + return in->f_op->splice_read(in, ppos, pipe, len, flags); } -long do_splice_direct(struct file *in, struct file *out, size_t len, - unsigned int flags) +long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, + size_t len, unsigned int flags) { struct pipe_inode_info *pipe; long ret, bytes; + loff_t out_off; umode_t i_mode; int i; @@ -820,6 +817,7 @@ long do_splice_direct(struct file *in, struct file *out, size_t len, */ ret = 0; bytes = 0; + out_off = 0; while (len) { size_t read_len, max_read_len; @@ -829,7 +827,7 @@ long do_splice_direct(struct file *in, struct file *out, size_t len, */ max_read_len = min(len, (size_t)(PIPE_BUFFERS*PAGE_SIZE)); - ret = do_splice_to(in, pipe, max_read_len, flags); + ret = do_splice_to(in, ppos, pipe, max_read_len, flags); if (unlikely(ret < 0)) goto out_release; @@ -840,7 +838,7 @@ long do_splice_direct(struct file *in, struct file *out, size_t len, * must not do the output in nonblocking mode as then we * could get stuck data in the internal pipe: */ - ret = do_splice_from(pipe, out, read_len, + ret = do_splice_from(pipe, out, &out_off, read_len, flags & ~SPLICE_F_NONBLOCK); if (unlikely(ret < 0)) goto out_release; @@ -898,6 +896,7 @@ static long do_splice(struct file *in, loff_t __user *off_in, size_t len, unsigned int flags) { struct pipe_inode_info *pipe; + loff_t offset, *off; pipe = in->f_dentry->d_inode->i_pipe; if (pipe) { @@ -906,12 +905,13 @@ static long do_splice(struct file *in, loff_t __user *off_in, if (off_out) { if (out->f_op->llseek == no_llseek) return -EINVAL; - if (copy_from_user(&out->f_pos, off_out, - sizeof(loff_t))) + if (copy_from_user(&offset, off_out, sizeof(loff_t))) return -EFAULT; - } + off = &offset; + } else + off = &out->f_pos; - return do_splice_from(pipe, out, len, flags); + return do_splice_from(pipe, out, off, len, flags); } pipe = out->f_dentry->d_inode->i_pipe; @@ -921,11 +921,13 @@ static long do_splice(struct file *in, loff_t __user *off_in, if (off_in) { if (in->f_op->llseek == no_llseek) return -EINVAL; - if (copy_from_user(&in->f_pos, off_in, sizeof(loff_t))) + if (copy_from_user(&offset, off_in, sizeof(loff_t))) return -EFAULT; - } + off = &offset; + } else + off = &in->f_pos; - return do_splice_to(in, pipe, len, flags); + return do_splice_to(in, off, pipe, len, flags); } return -EINVAL; diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c index 269721a..c847416 100644 --- a/fs/xfs/linux-2.6/xfs_file.c +++ b/fs/xfs/linux-2.6/xfs_file.c @@ -252,6 +252,7 @@ xfs_file_sendfile_invis( STATIC ssize_t xfs_file_splice_read( struct file *infilp, + loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags) @@ -259,13 +260,14 @@ xfs_file_splice_read( vnode_t *vp = vn_from_inode(infilp->f_dentry->d_inode); ssize_t rval; - VOP_SPLICE_READ(vp, infilp, pipe, len, flags, 0, NULL, rval); + VOP_SPLICE_READ(vp, infilp, ppos, pipe, len, flags, 0, NULL, rval); return rval; } STATIC ssize_t xfs_file_splice_read_invis( struct file *infilp, + loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags) @@ -273,7 +275,7 @@ xfs_file_splice_read_invis( vnode_t *vp = vn_from_inode(infilp->f_dentry->d_inode); ssize_t rval; - VOP_SPLICE_READ(vp, infilp, pipe, len, flags, IO_INVIS, NULL, rval); + VOP_SPLICE_READ(vp, infilp, ppos, pipe, len, flags, IO_INVIS, NULL, rval); return rval; } @@ -281,13 +283,14 @@ STATIC ssize_t xfs_file_splice_write( struct pipe_inode_info *pipe, struct file *outfilp, + loff_t *ppos, size_t len, unsigned int flags) { vnode_t *vp = vn_from_inode(outfilp->f_dentry->d_inode); ssize_t rval; - VOP_SPLICE_WRITE(vp, pipe, outfilp, len, flags, 0, NULL, rval); + VOP_SPLICE_WRITE(vp, pipe, outfilp, ppos, len, flags, 0, NULL, rval); return rval; } @@ -295,13 +298,14 @@ STATIC ssize_t xfs_file_splice_write_invis( struct pipe_inode_info *pipe, struct file *outfilp, + loff_t *ppos, size_t len, unsigned int flags) { vnode_t *vp = vn_from_inode(outfilp->f_dentry->d_inode); ssize_t rval; - VOP_SPLICE_WRITE(vp, pipe, outfilp, len, flags, IO_INVIS, NULL, rval); + VOP_SPLICE_WRITE(vp, pipe, outfilp, ppos, len, flags, IO_INVIS, NULL, rval); return rval; } diff --git a/fs/xfs/linux-2.6/xfs_lrw.c b/fs/xfs/linux-2.6/xfs_lrw.c index 74a52937..67efe33 100644 --- a/fs/xfs/linux-2.6/xfs_lrw.c +++ b/fs/xfs/linux-2.6/xfs_lrw.c @@ -338,6 +338,7 @@ ssize_t xfs_splice_read( bhv_desc_t *bdp, struct file *infilp, + loff_t *ppos, struct pipe_inode_info *pipe, size_t count, int flags, @@ -360,7 +361,7 @@ xfs_splice_read( int error; error = XFS_SEND_DATA(mp, DM_EVENT_READ, BHV_TO_VNODE(bdp), - infilp->f_pos, count, + *ppos, count, FILP_DELAY_FLAG(infilp), &locktype); if (error) { xfs_iunlock(ip, XFS_IOLOCK_SHARED); @@ -368,8 +369,8 @@ xfs_splice_read( } } xfs_rw_enter_trace(XFS_SPLICE_READ_ENTER, &ip->i_iocore, - pipe, count, infilp->f_pos, ioflags); - ret = generic_file_splice_read(infilp, pipe, count, flags); + pipe, count, *ppos, ioflags); + ret = generic_file_splice_read(infilp, ppos, pipe, count, flags); if (ret > 0) XFS_STATS_ADD(xs_read_bytes, ret); @@ -382,6 +383,7 @@ xfs_splice_write( bhv_desc_t *bdp, struct pipe_inode_info *pipe, struct file *outfilp, + loff_t *ppos, size_t count, int flags, int ioflags, @@ -403,7 +405,7 @@ xfs_splice_write( int error; error = XFS_SEND_DATA(mp, DM_EVENT_WRITE, BHV_TO_VNODE(bdp), - outfilp->f_pos, count, + *ppos, count, FILP_DELAY_FLAG(outfilp), &locktype); if (error) { xfs_iunlock(ip, XFS_IOLOCK_EXCL); @@ -411,8 +413,8 @@ xfs_splice_write( } } xfs_rw_enter_trace(XFS_SPLICE_WRITE_ENTER, &ip->i_iocore, - pipe, count, outfilp->f_pos, ioflags); - ret = generic_file_splice_write(pipe, outfilp, count, flags); + pipe, count, *ppos, ioflags); + ret = generic_file_splice_write(pipe, outfilp, ppos, count, flags); if (ret > 0) XFS_STATS_ADD(xs_write_bytes, ret); diff --git a/fs/xfs/linux-2.6/xfs_lrw.h b/fs/xfs/linux-2.6/xfs_lrw.h index 55c689a..8f45399 100644 --- a/fs/xfs/linux-2.6/xfs_lrw.h +++ b/fs/xfs/linux-2.6/xfs_lrw.h @@ -93,11 +93,11 @@ extern ssize_t xfs_write(struct bhv_desc *, struct kiocb *, extern ssize_t xfs_sendfile(struct bhv_desc *, struct file *, loff_t *, int, size_t, read_actor_t, void *, struct cred *); -extern ssize_t xfs_splice_read(struct bhv_desc *, struct file *, +extern ssize_t xfs_splice_read(struct bhv_desc *, struct file *, loff_t *, struct pipe_inode_info *, size_t, int, int, struct cred *); extern ssize_t xfs_splice_write(struct bhv_desc *, struct pipe_inode_info *, - struct file *, size_t, int, int, + struct file *, loff_t *, size_t, int, int, struct cred *); #endif /* __XFS_LRW_H__ */ diff --git a/fs/xfs/linux-2.6/xfs_vnode.h b/fs/xfs/linux-2.6/xfs_vnode.h index 88b09f1..2a8e16c 100644 --- a/fs/xfs/linux-2.6/xfs_vnode.h +++ b/fs/xfs/linux-2.6/xfs_vnode.h @@ -173,11 +173,11 @@ typedef ssize_t (*vop_write_t)(bhv_desc_t *, struct kiocb *, typedef ssize_t (*vop_sendfile_t)(bhv_desc_t *, struct file *, loff_t *, int, size_t, read_actor_t, void *, struct cred *); -typedef ssize_t (*vop_splice_read_t)(bhv_desc_t *, struct file *, +typedef ssize_t (*vop_splice_read_t)(bhv_desc_t *, struct file *, loff_t *, struct pipe_inode_info *, size_t, int, int, struct cred *); typedef ssize_t (*vop_splice_write_t)(bhv_desc_t *, struct pipe_inode_info *, - struct file *, size_t, int, int, + struct file *, loff_t *, size_t, int, int, struct cred *); typedef int (*vop_ioctl_t)(bhv_desc_t *, struct inode *, struct file *, int, unsigned int, void __user *); @@ -284,10 +284,10 @@ typedef struct vnodeops { rv = _VOP_(vop_write, vp)((vp)->v_fbhv,file,iov,segs,offset,ioflags,cr) #define VOP_SENDFILE(vp,f,off,ioflags,cnt,act,targ,cr,rv) \ rv = _VOP_(vop_sendfile, vp)((vp)->v_fbhv,f,off,ioflags,cnt,act,targ,cr) -#define VOP_SPLICE_READ(vp,f,pipe,cnt,fl,iofl,cr,rv) \ - rv = _VOP_(vop_splice_read, vp)((vp)->v_fbhv,f,pipe,cnt,fl,iofl,cr) -#define VOP_SPLICE_WRITE(vp,f,pipe,cnt,fl,iofl,cr,rv) \ - rv = _VOP_(vop_splice_write, vp)((vp)->v_fbhv,f,pipe,cnt,fl,iofl,cr) +#define VOP_SPLICE_READ(vp,f,o,pipe,cnt,fl,iofl,cr,rv) \ + rv = _VOP_(vop_splice_read, vp)((vp)->v_fbhv,f,o,pipe,cnt,fl,iofl,cr) +#define VOP_SPLICE_WRITE(vp,f,o,pipe,cnt,fl,iofl,cr,rv) \ + rv = _VOP_(vop_splice_write, vp)((vp)->v_fbhv,f,o,pipe,cnt,fl,iofl,cr) #define VOP_BMAP(vp,of,sz,rw,b,n,rv) \ rv = _VOP_(vop_bmap, vp)((vp)->v_fbhv,of,sz,rw,b,n) #define VOP_OPEN(vp, cr, rv) \ -- cgit v1.1 From 70524490ee2ea1bbf6cee6c106597b3ac25a3fc2 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 11 Apr 2006 15:51:17 +0200 Subject: [PATCH] splice: add support for sys_tee() Basically an in-kernel implementation of tee, which uses splice and the pipe buffers as an intelligent way to pass data around by reference. Where the user space tee consumes the input and produces a stdout and file output, this syscall merely duplicates the data inside a pipe to another pipe. No data is copied, the output just grabs a reference to the input pipe data. Signed-off-by: Jens Axboe --- fs/pipe.c | 7 +++ fs/splice.c | 186 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 193 insertions(+) (limited to 'fs') diff --git a/fs/pipe.c b/fs/pipe.c index e984beb..7fefb10 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -131,12 +131,19 @@ static int anon_pipe_buf_steal(struct pipe_inode_info *pipe, return 0; } +static void anon_pipe_buf_get(struct pipe_inode_info *info, + struct pipe_buffer *buf) +{ + page_cache_get(buf->page); +} + static struct pipe_buf_operations anon_pipe_buf_ops = { .can_merge = 1, .map = anon_pipe_buf_map, .unmap = anon_pipe_buf_unmap, .release = anon_pipe_buf_release, .steal = anon_pipe_buf_steal, + .get = anon_pipe_buf_get, }; static ssize_t diff --git a/fs/splice.c b/fs/splice.c index 5d3eda6..8d57e89 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -125,12 +125,19 @@ static void page_cache_pipe_buf_unmap(struct pipe_inode_info *info, kunmap(buf->page); } +static void page_cache_pipe_buf_get(struct pipe_inode_info *info, + struct pipe_buffer *buf) +{ + page_cache_get(buf->page); +} + static struct pipe_buf_operations page_cache_pipe_buf_ops = { .can_merge = 0, .map = page_cache_pipe_buf_map, .unmap = page_cache_pipe_buf_unmap, .release = page_cache_pipe_buf_release, .steal = page_cache_pipe_buf_steal, + .get = page_cache_pipe_buf_get, }; /* @@ -963,3 +970,182 @@ asmlinkage long sys_splice(int fd_in, loff_t __user *off_in, return error; } + +/* + * Link contents of ipipe to opipe. + */ +static int link_pipe(struct pipe_inode_info *ipipe, + struct pipe_inode_info *opipe, + size_t len, unsigned int flags) +{ + struct pipe_buffer *ibuf, *obuf; + int ret = 0, do_wakeup = 0, i; + + /* + * Potential ABBA deadlock, work around it by ordering lock + * grabbing by inode address. Otherwise two different processes + * could deadlock (one doing tee from A -> B, the other from B -> A). + */ + if (ipipe->inode < opipe->inode) { + mutex_lock(&ipipe->inode->i_mutex); + mutex_lock(&opipe->inode->i_mutex); + } else { + mutex_lock(&opipe->inode->i_mutex); + mutex_lock(&ipipe->inode->i_mutex); + } + + for (i = 0;; i++) { + if (!opipe->readers) { + send_sig(SIGPIPE, current, 0); + if (!ret) + ret = -EPIPE; + break; + } + if (ipipe->nrbufs - i) { + ibuf = ipipe->bufs + ((ipipe->curbuf + i) & (PIPE_BUFFERS - 1)); + + /* + * If we have room, fill this buffer + */ + if (opipe->nrbufs < PIPE_BUFFERS) { + int nbuf = (opipe->curbuf + opipe->nrbufs) & (PIPE_BUFFERS - 1); + + /* + * Get a reference to this pipe buffer, + * so we can copy the contents over. + */ + ibuf->ops->get(ipipe, ibuf); + + obuf = opipe->bufs + nbuf; + *obuf = *ibuf; + + if (obuf->len > len) + obuf->len = len; + + opipe->nrbufs++; + do_wakeup = 1; + ret += obuf->len; + len -= obuf->len; + + if (!len) + break; + if (opipe->nrbufs < PIPE_BUFFERS) + continue; + } + + /* + * We have input available, but no output room. + * If we already copied data, return that. + */ + if (flags & SPLICE_F_NONBLOCK) { + if (!ret) + ret = -EAGAIN; + break; + } + if (signal_pending(current)) { + if (!ret) + ret = -ERESTARTSYS; + break; + } + if (do_wakeup) { + smp_mb(); + if (waitqueue_active(&opipe->wait)) + wake_up_interruptible(&opipe->wait); + kill_fasync(&opipe->fasync_readers, SIGIO, POLL_IN); + do_wakeup = 0; + } + + opipe->waiting_writers++; + pipe_wait(opipe); + opipe->waiting_writers--; + continue; + } + + /* + * No input buffers, do the usual checks for available + * writers and blocking and wait if necessary + */ + if (!ipipe->writers) + break; + if (!ipipe->waiting_writers) { + if (ret) + break; + } + if (flags & SPLICE_F_NONBLOCK) { + if (!ret) + ret = -EAGAIN; + break; + } + if (signal_pending(current)) { + if (!ret) + ret = -ERESTARTSYS; + break; + } + + if (waitqueue_active(&ipipe->wait)) + wake_up_interruptible_sync(&ipipe->wait); + kill_fasync(&ipipe->fasync_writers, SIGIO, POLL_OUT); + + pipe_wait(ipipe); + } + + mutex_unlock(&ipipe->inode->i_mutex); + mutex_unlock(&opipe->inode->i_mutex); + + if (do_wakeup) { + smp_mb(); + if (waitqueue_active(&opipe->wait)) + wake_up_interruptible(&opipe->wait); + kill_fasync(&opipe->fasync_readers, SIGIO, POLL_IN); + } + + return ret; +} + +/* + * This is a tee(1) implementation that works on pipes. It doesn't copy + * any data, it simply references the 'in' pages on the 'out' pipe. + * The 'flags' used are the SPLICE_F_* variants, currently the only + * applicable one is SPLICE_F_NONBLOCK. + */ +static long do_tee(struct file *in, struct file *out, size_t len, + unsigned int flags) +{ + struct pipe_inode_info *ipipe = in->f_dentry->d_inode->i_pipe; + struct pipe_inode_info *opipe = out->f_dentry->d_inode->i_pipe; + + /* + * Link ipipe to the two output pipes, consuming as we go along. + */ + if (ipipe && opipe) + return link_pipe(ipipe, opipe, len, flags); + + return -EINVAL; +} + +asmlinkage long sys_tee(int fdin, int fdout, size_t len, unsigned int flags) +{ + struct file *in; + int error, fput_in; + + if (unlikely(!len)) + return 0; + + error = -EBADF; + in = fget_light(fdin, &fput_in); + if (in) { + if (in->f_mode & FMODE_READ) { + int fput_out; + struct file *out = fget_light(fdout, &fput_out); + + if (out) { + if (out->f_mode & FMODE_WRITE) + error = do_tee(in, out, len, flags); + fput_light(out, fput_out); + } + } + fput_light(in, fput_in); + } + + return error; +} -- cgit v1.1