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 +++++++++++++++++++++++++++++++------------------------------ 1 file changed, 44 insertions(+), 42 deletions(-) (limited to 'fs/splice.c') diff --git a/fs/splice.c b/fs/splice.c index e50a460239dd..5d3eda64703b 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; -- cgit v1.2.3-55-g7522