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sendfile(): check f_op.splice_write() rather than f_op.sendpage()

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sendfile(2) was reworked with the splice infrastructure, but it still
checks f_op.sendpage() instead of f_op.splice_write() wrongly.  Although
if f_op.sendpage() exists, f_op.splice_write() always exists at the same
time currently, the assumption will be broken in future silently.  This
patch also brings a side effect: sendfile(2) can work with any output
file.  Some security checks related to f_op are added too.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Changli Gao 2009-11-04 09:09:52 +01:00 committed by Jens Axboe
parent f21121cde6
commit cc56f7de7f
2 changed files with 15 additions and 11 deletions
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2
fs/read_write.c
View file

@ -826,8 +826,6 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
if (!(out_file->f_mode & FMODE_WRITE))
goto fput_out;
retval = -EINVAL;
if (!out_file->f_op || !out_file->f_op->sendpage)
goto fput_out;
in_inode = in_file->f_path.dentry->d_inode;
out_inode = out_file->f_path.dentry->d_inode;
retval = rw_verify_area(WRITE, out_file, &out_file->f_pos, count);

24
fs/splice.c
View file

@ -648,9 +648,11 @@ static int pipe_to_sendpage(struct pipe_inode_info *pipe,
ret = buf->ops->confirm(pipe, buf);
if (!ret) {
more = (sd->flags & SPLICE_F_MORE) || sd->len < sd->total_len;
ret = file->f_op->sendpage(file, buf->page, buf->offset,
sd->len, &pos, more);
if (file->f_op && file->f_op->sendpage)
ret = file->f_op->sendpage(file, buf->page, buf->offset,
sd->len, &pos, more);
else
ret = -EINVAL;
}
return ret;
@ -1068,8 +1070,9 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
if (unlikely(ret < 0))
return ret;
splice_write = out->f_op->splice_write;
if (!splice_write)
if (out->f_op && out->f_op->splice_write)
splice_write = out->f_op->splice_write;
else
splice_write = default_file_splice_write;
return splice_write(pipe, out, ppos, len, flags);
@ -1093,8 +1096,9 @@ static long do_splice_to(struct file *in, loff_t *ppos,
if (unlikely(ret < 0))
return ret;
splice_read = in->f_op->splice_read;
if (!splice_read)
if (in->f_op && in->f_op->splice_read)
splice_read = in->f_op->splice_read;
else
splice_read = default_file_splice_read;
return splice_read(in, ppos, pipe, len, flags);
@ -1316,7 +1320,8 @@ static long do_splice(struct file *in, loff_t __user *off_in,
if (off_in)
return -ESPIPE;
if (off_out) {
if (out->f_op->llseek == no_llseek)
if (!out->f_op || !out->f_op->llseek ||
out->f_op->llseek == no_llseek)
return -EINVAL;
if (copy_from_user(&offset, off_out, sizeof(loff_t)))
return -EFAULT;
@ -1336,7 +1341,8 @@ static long do_splice(struct file *in, loff_t __user *off_in,
if (off_out)
return -ESPIPE;
if (off_in) {
if (in->f_op->llseek == no_llseek)
if (!in->f_op || !in->f_op->llseek ||
in->f_op->llseek == no_llseek)
return -EINVAL;
if (copy_from_user(&offset, off_in, sizeof(loff_t)))
return -EFAULT;