Commit d37d4166 authored by Michael Kerrisk (man-pages)'s avatar Michael Kerrisk (man-pages) Committed by Linus Torvalds

pipe: move limit checking logic into pipe_set_size()

This is a preparatory patch for following work. Move the F_SETPIPE_SZ
limit-checking logic from pipe_fcntl() into pipe_set_size().  This
simplifies the code a little, and allows for reworking required in
a later patch that fixes the limit checking in pipe_set_size()

Link: http://lkml.kernel.org/r/3701b2c5-2c52-2c3e-226d-29b9deb29b50@gmail.comSigned-off-by: default avatarMichael Kerrisk <mtk.manpages@gmail.com>
Reviewed-by: default avatarVegard Nossum <vegard.nossum@oracle.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: <socketpair@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Jens Axboe <axboe@fb.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f491bd71
...@@ -1023,9 +1023,24 @@ static inline unsigned int round_pipe_size(unsigned int size) ...@@ -1023,9 +1023,24 @@ static inline unsigned int round_pipe_size(unsigned int size)
* Allocate a new array of pipe buffers and copy the info over. Returns the * Allocate a new array of pipe buffers and copy the info over. Returns the
* pipe size if successful, or return -ERROR on error. * pipe size if successful, or return -ERROR on error.
*/ */
static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long nr_pages) static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long arg)
{ {
struct pipe_buffer *bufs; struct pipe_buffer *bufs;
unsigned int size, nr_pages;
size = round_pipe_size(arg);
nr_pages = size >> PAGE_SHIFT;
if (!nr_pages)
return -EINVAL;
if (!capable(CAP_SYS_RESOURCE) && size > pipe_max_size)
return -EPERM;
if ((too_many_pipe_buffers_hard(pipe->user) ||
too_many_pipe_buffers_soft(pipe->user)) &&
!capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN))
return -EPERM;
/* /*
* We can shrink the pipe, if arg >= pipe->nrbufs. Since we don't * We can shrink the pipe, if arg >= pipe->nrbufs. Since we don't
...@@ -1109,28 +1124,9 @@ long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg) ...@@ -1109,28 +1124,9 @@ long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg)
__pipe_lock(pipe); __pipe_lock(pipe);
switch (cmd) { switch (cmd) {
case F_SETPIPE_SZ: { case F_SETPIPE_SZ:
unsigned int size, nr_pages; ret = pipe_set_size(pipe, arg);
size = round_pipe_size(arg);
nr_pages = size >> PAGE_SHIFT;
ret = -EINVAL;
if (!nr_pages)
goto out;
if (!capable(CAP_SYS_RESOURCE) && size > pipe_max_size) {
ret = -EPERM;
goto out;
} else if ((too_many_pipe_buffers_hard(pipe->user) ||
too_many_pipe_buffers_soft(pipe->user)) &&
!capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN)) {
ret = -EPERM;
goto out;
}
ret = pipe_set_size(pipe, nr_pages);
break; break;
}
case F_GETPIPE_SZ: case F_GETPIPE_SZ:
ret = pipe->buffers * PAGE_SIZE; ret = pipe->buffers * PAGE_SIZE;
break; break;
...@@ -1139,7 +1135,6 @@ long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg) ...@@ -1139,7 +1135,6 @@ long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg)
break; break;
} }
out:
__pipe_unlock(pipe); __pipe_unlock(pipe);
return ret; return ret;
} }
......
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