summaryrefslogtreecommitdiff
path: root/fs/pipe.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/pipe.c')
-rw-r--r--fs/pipe.c35
1 files changed, 20 insertions, 15 deletions
diff --git a/fs/pipe.c b/fs/pipe.c
index db6eaaba0dd8..541d6626f9d9 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -1118,26 +1118,20 @@ SYSCALL_DEFINE1(pipe, int __user *, fildes)
* Allocate a new array of pipe buffers and copy the info over. Returns the
* pipe size if successful, or return -ERROR on error.
*/
-static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long arg)
+static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long nr_pages)
{
struct pipe_buffer *bufs;
/*
- * Must be a power-of-2 currently
- */
- if (!is_power_of_2(arg))
- return -EINVAL;
-
- /*
* We can shrink the pipe, if arg >= pipe->nrbufs. Since we don't
* expect a lot of shrink+grow operations, just free and allocate
* again like we would do for growing. If the pipe currently
* contains more buffers than arg, then return busy.
*/
- if (arg < pipe->nrbufs)
+ if (nr_pages < pipe->nrbufs)
return -EBUSY;
- bufs = kcalloc(arg, sizeof(struct pipe_buffer), GFP_KERNEL);
+ bufs = kcalloc(nr_pages, sizeof(struct pipe_buffer), GFP_KERNEL);
if (unlikely(!bufs))
return -ENOMEM;
@@ -1158,8 +1152,8 @@ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long arg)
pipe->curbuf = 0;
kfree(pipe->bufs);
pipe->bufs = bufs;
- pipe->buffers = arg;
- return arg;
+ pipe->buffers = nr_pages;
+ return nr_pages * PAGE_SIZE;
}
long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg)
@@ -1174,11 +1168,21 @@ long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg)
mutex_lock(&pipe->inode->i_mutex);
switch (cmd) {
- case F_SETPIPE_SZ:
- if (!capable(CAP_SYS_ADMIN) && arg > pipe_max_pages) {
- ret = -EINVAL;
+ case F_SETPIPE_SZ: {
+ unsigned long nr_pages;
+
+ /*
+ * Currently the array must be a power-of-2 size, so adjust
+ * upwards if needed.
+ */
+ nr_pages = (arg + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ nr_pages = roundup_pow_of_two(nr_pages);
+
+ if (!capable(CAP_SYS_ADMIN) && nr_pages > pipe_max_pages) {
+ ret = -EPERM;
goto out;
}
+
/*
* The pipe needs to be at least 2 pages large to
* guarantee POSIX behaviour.
@@ -1189,8 +1193,9 @@ long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg)
}
ret = pipe_set_size(pipe, arg);
break;
+ }
case F_GETPIPE_SZ:
- ret = pipe->buffers;
+ ret = pipe->buffers * PAGE_SIZE;
break;
default:
ret = -EINVAL;