fs: move pipe sysctls to is own file

kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.

To help with this maintenance let's start by moving sysctls to places
where they actually belong.  The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we
just care about the core logic.

So move the pipe sysctls to its own file.

Link: https://lkml.kernel.org/r/20211129205548.605569-10-mcgrof@kernel.org
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Antti Palosaari <crope@iki.fi>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Lukas Middendorf <kernel@tuxforce.de>
Cc: Stephen Kitt <steve@sk2.org>
Cc: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/pipe.c b/fs/pipe.c
index 6d4342bad9f15b258134fec2374955588f901de4..cc28623a67b61422472d05b9b040e88e640c99d8 100644 (file)
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -25,6 +25,7 @@
 #include <linux/fcntl.h>
 #include <linux/memcontrol.h>
 #include <linux/watch_queue.h>
+#include <linux/sysctl.h>
 
 #include <linux/uaccess.h>
 #include <asm/ioctls.h>
@@ -50,13 +51,13 @@
  * The max size that a non-root user is allowed to grow the pipe. Can
  * be set by root in /proc/sys/fs/pipe-max-size
  */
-unsigned int pipe_max_size = 1048576;
+static unsigned int pipe_max_size = 1048576;
 
 /* Maximum allocatable pages per user. Hard limit is unset by default, soft
  * matches default values.
  */
-unsigned long pipe_user_pages_hard;
-unsigned long pipe_user_pages_soft = PIPE_DEF_BUFFERS * INR_OPEN_CUR;
+static unsigned long pipe_user_pages_hard;
+static unsigned long pipe_user_pages_soft = PIPE_DEF_BUFFERS * INR_OPEN_CUR;
 
 /*
  * We use head and tail indices that aren't masked off, except at the point of
@@ -1428,6 +1429,60 @@ static struct file_system_type pipe_fs_type = {
        .kill_sb        = kill_anon_super,
 };
 
+#ifdef CONFIG_SYSCTL
+static int do_proc_dopipe_max_size_conv(unsigned long *lvalp,
+                                       unsigned int *valp,
+                                       int write, void *data)
+{
+       if (write) {
+               unsigned int val;
+
+               val = round_pipe_size(*lvalp);
+               if (val == 0)
+                       return -EINVAL;
+
+               *valp = val;
+       } else {
+               unsigned int val = *valp;
+               *lvalp = (unsigned long) val;
+       }
+
+       return 0;
+}
+
+static int proc_dopipe_max_size(struct ctl_table *table, int write,
+                               void *buffer, size_t *lenp, loff_t *ppos)
+{
+       return do_proc_douintvec(table, write, buffer, lenp, ppos,
+                                do_proc_dopipe_max_size_conv, NULL);
+}
+
+static struct ctl_table fs_pipe_sysctls[] = {
+       {
+               .procname       = "pipe-max-size",
+               .data           = &pipe_max_size,
+               .maxlen         = sizeof(pipe_max_size),
+               .mode           = 0644,
+               .proc_handler   = proc_dopipe_max_size,
+       },
+       {
+               .procname       = "pipe-user-pages-hard",
+               .data           = &pipe_user_pages_hard,
+               .maxlen         = sizeof(pipe_user_pages_hard),
+               .mode           = 0644,
+               .proc_handler   = proc_doulongvec_minmax,
+       },
+       {
+               .procname       = "pipe-user-pages-soft",
+               .data           = &pipe_user_pages_soft,
+               .maxlen         = sizeof(pipe_user_pages_soft),
+               .mode           = 0644,
+               .proc_handler   = proc_doulongvec_minmax,
+       },
+       { }
+};
+#endif
+
 static int __init init_pipe_fs(void)
 {
        int err = register_filesystem(&pipe_fs_type);
@@ -1439,6 +1494,9 @@ static int __init init_pipe_fs(void)
                        unregister_filesystem(&pipe_fs_type);
                }
        }
+#ifdef CONFIG_SYSCTL
+       register_sysctl_init("fs", fs_pipe_sysctls);
+#endif
        return err;
 }
 

diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index fc5642431b923cd8c1bf33d884ad348a43924377..c00c618ef290d726874d18c00c174e71d215a4ae 100644 (file)
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -238,10 +238,6 @@ void pipe_lock(struct pipe_inode_info *);
 void pipe_unlock(struct pipe_inode_info *);
 void pipe_double_lock(struct pipe_inode_info *, struct pipe_inode_info *);
 
-extern unsigned int pipe_max_size;
-extern unsigned long pipe_user_pages_hard;
-extern unsigned long pipe_user_pages_soft;
-
 /* Wait for a pipe to be readable/writable while dropping the pipe lock */
 void pipe_wait_readable(struct pipe_inode_info *);
 void pipe_wait_writable(struct pipe_inode_info *);

diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index bb921eb8a02d4ff62cb5c67b4dc4818b082cb967..4294e9668bd517739ebc7189b2d58ccbb6a6e43a 100644 (file)
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -221,6 +221,12 @@ extern void __register_sysctl_init(const char *path, struct ctl_table *table,
 extern struct ctl_table_header *register_sysctl_mount_point(const char *path);
 
 void do_sysctl_args(void);
+int do_proc_douintvec(struct ctl_table *table, int write,
+                     void *buffer, size_t *lenp, loff_t *ppos,
+                     int (*conv)(unsigned long *lvalp,
+                                 unsigned int *valp,
+                                 int write, void *data),
+                     void *data);
 
 extern int pwrsw_enabled;
 extern int unaligned_enabled;

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 8bab82aa0192392c910fabefe61bcb787fe1620f..f79ec2cf8721a7cffe69426e5b5df8c6cfb66aed 100644 (file)
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -57,7 +57,6 @@
 #include <linux/ftrace.h>
 #include <linux/perf_event.h>
 #include <linux/kprobes.h>
-#include <linux/pipe_fs_i.h>
 #include <linux/oom.h>
 #include <linux/kmod.h>
 #include <linux/capability.h>
@@ -761,12 +760,12 @@ static int __do_proc_douintvec(void *tbl_data, struct ctl_table *table,
        return do_proc_douintvec_r(i, buffer, lenp, ppos, conv, data);
 }
 
-static int do_proc_douintvec(struct ctl_table *table, int write,
-                            void *buffer, size_t *lenp, loff_t *ppos,
-                            int (*conv)(unsigned long *lvalp,
-                                        unsigned int *valp,
-                                        int write, void *data),
-                            void *data)
+int do_proc_douintvec(struct ctl_table *table, int write,
+                     void *buffer, size_t *lenp, loff_t *ppos,
+                     int (*conv)(unsigned long *lvalp,
+                                 unsigned int *valp,
+                                 int write, void *data),
+                     void *data)
 {
        return __do_proc_douintvec(table->data, table, write,
                                   buffer, lenp, ppos, conv, data);
@@ -1090,33 +1089,6 @@ int proc_dou8vec_minmax(struct ctl_table *table, int write,
 }
 EXPORT_SYMBOL_GPL(proc_dou8vec_minmax);
 
-static int do_proc_dopipe_max_size_conv(unsigned long *lvalp,
-                                       unsigned int *valp,
-                                       int write, void *data)
-{
-       if (write) {
-               unsigned int val;
-
-               val = round_pipe_size(*lvalp);
-               if (val == 0)
-                       return -EINVAL;
-
-               *valp = val;
-       } else {
-               unsigned int val = *valp;
-               *lvalp = (unsigned long) val;
-       }
-
-       return 0;
-}
-
-static int proc_dopipe_max_size(struct ctl_table *table, int write,
-                               void *buffer, size_t *lenp, loff_t *ppos)
-{
-       return do_proc_douintvec(table, write, buffer, lenp, ppos,
-                                do_proc_dopipe_max_size_conv, NULL);
-}
-
 #ifdef CONFIG_MAGIC_SYSRQ
 static int sysrq_sysctl_handler(struct ctl_table *table, int write,
                                void *buffer, size_t *lenp, loff_t *ppos)
@@ -2840,27 +2812,6 @@ static struct ctl_table vm_table[] = {
 };
 
 static struct ctl_table fs_table[] = {
-       {
-               .procname       = "pipe-max-size",
-               .data           = &pipe_max_size,
-               .maxlen         = sizeof(pipe_max_size),
-               .mode           = 0644,
-               .proc_handler   = proc_dopipe_max_size,
-       },
-       {
-               .procname       = "pipe-user-pages-hard",
-               .data           = &pipe_user_pages_hard,
-               .maxlen         = sizeof(pipe_user_pages_hard),
-               .mode           = 0644,
-               .proc_handler   = proc_doulongvec_minmax,
-       },
-       {
-               .procname       = "pipe-user-pages-soft",
-               .data           = &pipe_user_pages_soft,
-               .maxlen         = sizeof(pipe_user_pages_soft),
-               .mode           = 0644,
-               .proc_handler   = proc_doulongvec_minmax,
-       },
        {
                .procname       = "mount-max",
                .data           = &sysctl_mount_max,