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author | Ingo Molnar <mingo@elte.hu> | 2006-04-10 15:18:58 +0200 |
---|---|---|
committer | Jens Axboe <axboe@suse.de> | 2006-04-10 15:18:58 +0200 |
commit | 529565dcb1581c9a1e3f6df1c1763ca3e0f0d512 (patch) | |
tree | e8069cc17f887ad86f8dee0d96640a2f19bf4112 /fs/splice.c | |
parent | 3a326a2ce88e71d00ac0d133e314a3342a7709f8 (diff) | |
download | op-kernel-dev-529565dcb1581c9a1e3f6df1c1763ca3e0f0d512.zip op-kernel-dev-529565dcb1581c9a1e3f6df1c1763ca3e0f0d512.tar.gz |
[PATCH] splice: add optional input and output offsets
add optional input and output offsets to sys_splice(), for seekable file
descriptors:
asmlinkage long sys_splice(int fd_in, loff_t __user *off_in,
int fd_out, loff_t __user *off_out,
size_t len, unsigned int flags);
semantics are straightforward: f_pos will be updated with the offset
provided by user-space, before the splice transfer is about to begin.
Providing a NULL offset pointer means the existing f_pos will be used
(and updated in situ). Providing an offset for a pipe results in
-ESPIPE. Providing an invalid offset pointer results in -EFAULT.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jens Axboe <axboe@suse.de>
Diffstat (limited to 'fs/splice.c')
-rw-r--r-- | fs/splice.c | 54 |
1 files changed, 41 insertions, 13 deletions
diff --git a/fs/splice.c b/fs/splice.c index ed91a62..a532612 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -680,7 +680,8 @@ 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 __user *off_out, size_t len, + unsigned int flags) { loff_t pos; int ret; @@ -691,7 +692,11 @@ 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); if (unlikely(ret < 0)) return ret; @@ -702,8 +707,9 @@ 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, struct pipe_inode_info *pipe, - size_t len, unsigned int flags) +static long do_splice_to(struct file *in, loff_t __user *off_in, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags) { loff_t pos, isize, left; int ret; @@ -714,7 +720,11 @@ static long do_splice_to(struct file *in, struct pipe_inode_info *pipe, 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); if (unlikely(ret < 0)) return ret; @@ -733,23 +743,39 @@ static long do_splice_to(struct file *in, struct pipe_inode_info *pipe, /* * Determine where to splice to/from. */ -static long do_splice(struct file *in, struct file *out, size_t len, - unsigned int flags) +static long do_splice(struct file *in, loff_t __user *off_in, + struct file *out, loff_t __user *off_out, + size_t len, unsigned int flags) { 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) - return do_splice_from(pipe, out, len, flags); + if (pipe) { + if (off_in) + return -ESPIPE; + + return do_splice_from(pipe, out, off_out, len, flags); + } pipe = out->f_dentry->d_inode->i_pipe; - if (pipe) - return do_splice_to(in, pipe, len, flags); + if (pipe) { + if (off_out) + return -ESPIPE; + + return do_splice_to(in, off_in, pipe, len, flags); + } return -EINVAL; } -asmlinkage long sys_splice(int fdin, int fdout, size_t len, unsigned int flags) +asmlinkage long sys_splice(int fd_in, loff_t __user *off_in, + int fd_out, loff_t __user *off_out, + size_t len, unsigned int flags) { long error; struct file *in, *out; @@ -759,13 +785,15 @@ asmlinkage long sys_splice(int fdin, int fdout, size_t len, unsigned int flags) return 0; error = -EBADF; - in = fget_light(fdin, &fput_in); + in = fget_light(fd_in, &fput_in); if (in) { if (in->f_mode & FMODE_READ) { - out = fget_light(fdout, &fput_out); + out = fget_light(fd_out, &fput_out); if (out) { if (out->f_mode & FMODE_WRITE) - error = do_splice(in, out, len, flags); + error = do_splice(in, off_in, + out, off_out, + len, flags); fput_light(out, fput_out); } } |