diff options
| -rw-r--r-- | fs/pipe.c | 10 | ||||
| -rw-r--r-- | fs/splice.c | 148 | ||||
| -rw-r--r-- | include/linux/fs.h | 2 | ||||
| -rw-r--r-- | include/linux/pipe_fs_i.h | 1 | ||||
| -rw-r--r-- | include/linux/sched.h | 6 | ||||
| -rw-r--r-- | kernel/exit.c | 4 |
6 files changed, 150 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; diff --git a/include/linux/fs.h b/include/linux/fs.h index 7e6454454fb..9e8e2ee353b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1613,6 +1613,8 @@ extern void do_generic_mapping_read(struct address_space *mapping, loff_t *, read_descriptor_t *, read_actor_t); extern ssize_t generic_file_splice_read(struct file *, struct pipe_inode_info *, size_t, unsigned int); extern ssize_t generic_file_splice_write(struct pipe_inode_info *, struct file *, size_t, unsigned int); +extern long do_splice_direct(struct file *in, struct file *out, + size_t len, unsigned int flags); extern void file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping); extern ssize_t generic_file_readv(struct file *filp, const struct iovec *iov, diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h index 9cf99cb34c1..660e9d866e5 100644 --- a/include/linux/pipe_fs_i.h +++ b/include/linux/pipe_fs_i.h @@ -58,6 +58,7 @@ void pipe_wait(struct pipe_inode_info *pipe); struct pipe_inode_info * alloc_pipe_info(struct inode * inode); void free_pipe_info(struct inode * inode); +void __free_pipe_info(struct pipe_inode_info *); /* * splice is tied to pipes as a transport (at least for now), so we'll just diff --git a/include/linux/sched.h b/include/linux/sched.h index 541f4828f5e..e194ec75833 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -684,6 +684,7 @@ static inline void prefetch_stack(struct task_struct *t) { } struct audit_context; /* See audit.c */ struct mempolicy; +struct pipe_inode_info; enum sleep_type { SLEEP_NORMAL, @@ -882,6 +883,11 @@ struct task_struct { atomic_t fs_excl; /* holding fs exclusive resources */ struct rcu_head rcu; + + /* + * cache last used pipe for splice + */ + struct pipe_inode_info *splice_pipe; }; static inline pid_t process_group(struct task_struct *tsk) diff --git a/kernel/exit.c b/kernel/exit.c index 6c2eeb8f639..1a9787ac617 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -34,6 +34,7 @@ #include <linux/mutex.h> #include <linux/futex.h> #include <linux/compat.h> +#include <linux/pipe_fs_i.h> #include <asm/uaccess.h> #include <asm/unistd.h> @@ -941,6 +942,9 @@ fastcall NORET_TYPE void do_exit(long code) if (tsk->io_context) exit_io_context(); + if (tsk->splice_pipe) + __free_pipe_info(tsk->splice_pipe); + /* PF_DEAD causes final put_task_struct after we schedule. */ preempt_disable(); BUG_ON(tsk->flags & PF_DEAD); |