diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/pipe.c | 10 | ||||
| -rw-r--r-- | fs/splice.c | 148 |
2 files changed, 137 insertions, 21 deletions
diff --git a/fs/pipe.c b/fs/pipe.c index 705b4869262..036536f072c 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -691,12 +691,10 @@ struct pipe_inode_info * alloc_pipe_info(struct inode *inode) return info; } -void free_pipe_info(struct inode *inode) +void __free_pipe_info(struct pipe_inode_info *info) { int i; - struct pipe_inode_info *info = inode->i_pipe; - inode->i_pipe = NULL; for (i = 0; i < PIPE_BUFFERS; i++) { struct pipe_buffer *buf = info->bufs + i; if (buf->ops) @@ -707,6 +705,12 @@ void free_pipe_info(struct inode *inode) kfree(info); } +void free_pipe_info(struct inode *inode) +{ + __free_pipe_info(inode->i_pipe); + inode->i_pipe = NULL; +} + static struct vfsmount *pipe_mnt __read_mostly; static int pipefs_delete_dentry(struct dentry *dentry) { diff --git a/fs/splice.c b/fs/splice.c index a5326127aad..c47b561edac 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -680,8 +680,7 @@ 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, - loff_t __user *off_out, size_t len, - unsigned int flags) + size_t len, unsigned int flags) { loff_t pos; int ret; @@ -692,9 +691,6 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out, if (!(out->f_mode & FMODE_WRITE)) return -EBADF; - if (off_out && copy_from_user(&out->f_pos, off_out, sizeof(loff_t))) - return -EFAULT; - pos = out->f_pos; ret = rw_verify_area(WRITE, out, &pos, len); @@ -707,9 +703,8 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out, /* * Attempt to initiate a splice from a file to a pipe. */ -static long do_splice_to(struct file *in, loff_t __user *off_in, - struct pipe_inode_info *pipe, size_t len, - unsigned int flags) +static long do_splice_to(struct file *in, struct pipe_inode_info *pipe, + size_t len, unsigned int flags) { loff_t pos, isize, left; int ret; @@ -720,9 +715,6 @@ static long do_splice_to(struct file *in, loff_t __user *off_in, if (!(in->f_mode & FMODE_READ)) return -EBADF; - if (off_in && copy_from_user(&in->f_pos, off_in, sizeof(loff_t))) - return -EFAULT; - pos = in->f_pos; ret = rw_verify_area(READ, in, &pos, len); @@ -740,6 +732,118 @@ static long do_splice_to(struct file *in, loff_t __user *off_in, return in->f_op->splice_read(in, pipe, len, flags); } +long do_splice_direct(struct file *in, struct file *out, size_t len, + unsigned int flags) +{ + struct pipe_inode_info *pipe; + long ret, bytes; + umode_t i_mode; + int i; + + /* + * We require the input being a regular file, as we don't want to + * randomly drop data for eg socket -> socket splicing. Use the + * piped splicing for that! + */ + i_mode = in->f_dentry->d_inode->i_mode; + if (unlikely(!S_ISREG(i_mode) && !S_ISBLK(i_mode))) + return -EINVAL; + + /* + * neither in nor out is a pipe, setup an internal pipe attached to + * 'out' and transfer the wanted data from 'in' to 'out' through that + */ + pipe = current->splice_pipe; + if (!pipe) { + pipe = alloc_pipe_info(NULL); + if (!pipe) + return -ENOMEM; + + /* + * We don't have an immediate reader, but we'll read the stuff + * out of the pipe right after the move_to_pipe(). So set + * PIPE_READERS appropriately. + */ + pipe->readers = 1; + + current->splice_pipe = pipe; + } + + /* + * do the splice + */ + ret = 0; + bytes = 0; + + while (len) { + size_t read_len, max_read_len; + + /* + * Do at most PIPE_BUFFERS pages worth of transfer: + */ + max_read_len = min(len, (size_t)(PIPE_BUFFERS*PAGE_SIZE)); + + ret = do_splice_to(in, pipe, max_read_len, flags); + if (unlikely(ret < 0)) + goto out_release; + + read_len = ret; + + /* + * NOTE: nonblocking mode only applies to the input. We + * 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, + flags & ~SPLICE_F_NONBLOCK); + if (unlikely(ret < 0)) + goto out_release; + + bytes += ret; + len -= ret; + + /* + * In nonblocking mode, if we got back a short read then + * that was due to either an IO error or due to the + * pagecache entry not being there. In the IO error case + * the _next_ splice attempt will produce a clean IO error + * return value (not a short read), so in both cases it's + * correct to break out of the loop here: + */ + if ((flags & SPLICE_F_NONBLOCK) && (read_len < max_read_len)) + break; + } + + pipe->nrbufs = pipe->curbuf = 0; + + return bytes; + +out_release: + /* + * If we did an incomplete transfer we must release + * the pipe buffers in question: + */ + for (i = 0; i < PIPE_BUFFERS; i++) { + struct pipe_buffer *buf = pipe->bufs + i; + + if (buf->ops) { + buf->ops->release(pipe, buf); + buf->ops = NULL; + } + } + pipe->nrbufs = pipe->curbuf = 0; + + /* + * If we transferred some data, return the number of bytes: + */ + if (bytes > 0) + return bytes; + + return ret; +} + +EXPORT_SYMBOL(do_splice_direct); + /* * Determine where to splice to/from. */ @@ -749,25 +853,33 @@ static long do_splice(struct file *in, loff_t __user *off_in, { struct pipe_inode_info *pipe; - if (off_out && out->f_op->llseek == no_llseek) - return -EINVAL; - if (off_in && in->f_op->llseek == no_llseek) - return -EINVAL; - pipe = in->f_dentry->d_inode->i_pipe; if (pipe) { if (off_in) return -ESPIPE; + if (off_out) { + if (out->f_op->llseek == no_llseek) + return -EINVAL; + if (copy_from_user(&out->f_pos, off_out, + sizeof(loff_t))) + return -EFAULT; + } - return do_splice_from(pipe, out, off_out, len, flags); + return do_splice_from(pipe, out, len, flags); } pipe = out->f_dentry->d_inode->i_pipe; if (pipe) { if (off_out) return -ESPIPE; + if (off_in) { + if (in->f_op->llseek == no_llseek) + return -EINVAL; + if (copy_from_user(&in->f_pos, off_in, sizeof(loff_t))) + return -EFAULT; + } - return do_splice_to(in, off_in, pipe, len, flags); + return do_splice_to(in, pipe, len, flags); } return -EINVAL; |