From: David Howells <dhowells@redhat.com>
To: viro@zeniv.linux.org.uk
Cc: dhowells@redhat.com, linux-fsdevel@vger.kernel.org,
linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH 13/32] proc: Add fs_context support to procfs [ver #8]
Date: Fri, 25 May 2018 01:06:48 +0100 [thread overview]
Message-ID: <152720680880.9073.13644233876944936872.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <152720672288.9073.9868393448836301272.stgit@warthog.procyon.org.uk>
Add fs_context support to procfs.
Signed-off-by: David Howells <dhowells@redhat.com>
---
fs/proc/inode.c | 2 -
fs/proc/internal.h | 2 -
fs/proc/root.c | 179 ++++++++++++++++++++++++++++++++++------------------
3 files changed, 120 insertions(+), 63 deletions(-)
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 0b13cf6eb6d7..7aa86dd65ba8 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -128,7 +128,7 @@ const struct super_operations proc_sops = {
.drop_inode = generic_delete_inode,
.evict_inode = proc_evict_inode,
.statfs = simple_statfs,
- .remount_fs = proc_remount,
+ .reconfigure = proc_reconfigure,
.show_options = proc_show_options,
};
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index c918ec4cc0d9..77254851327c 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -265,7 +265,7 @@ static inline void proc_tty_init(void) {}
extern struct proc_dir_entry proc_root;
extern void proc_self_init(void);
-extern int proc_remount(struct super_block *, int *, char *, size_t);
+extern int proc_reconfigure(struct super_block *, struct fs_context *);
/*
* task_[no]mmu.c
diff --git a/fs/proc/root.c b/fs/proc/root.c
index 2fbc177f37a8..a379edccd880 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -19,14 +19,23 @@
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/user_namespace.h>
+#include <linux/fs_context.h>
#include <linux/mount.h>
#include <linux/pid_namespace.h>
#include <linux/parser.h>
#include <linux/cred.h>
#include <linux/magic.h>
+#include <linux/slab.h>
#include "internal.h"
+struct proc_fs_context {
+ struct pid_namespace *pid_ns;
+ unsigned long mask;
+ int hidepid;
+ int gid;
+};
+
enum {
Opt_gid, Opt_hidepid, Opt_err,
};
@@ -37,56 +46,60 @@ static const match_table_t tokens = {
{Opt_err, NULL},
};
-static int proc_parse_options(char *options, struct pid_namespace *pid)
+static int proc_parse_option(struct fs_context *fc, char *opt, size_t len)
{
- char *p;
+ struct proc_fs_context *ctx = fc->fs_private;
substring_t args[MAX_OPT_ARGS];
- int option;
-
- if (!options)
- return 1;
-
- while ((p = strsep(&options, ",")) != NULL) {
- int token;
- if (!*p)
- continue;
-
- args[0].to = args[0].from = NULL;
- token = match_token(p, tokens, args);
- switch (token) {
- case Opt_gid:
- if (match_int(&args[0], &option))
- return 0;
- pid->pid_gid = make_kgid(current_user_ns(), option);
- break;
- case Opt_hidepid:
- if (match_int(&args[0], &option))
- return 0;
- if (option < HIDEPID_OFF ||
- option > HIDEPID_INVISIBLE) {
- pr_err("proc: hidepid value must be between 0 and 2.\n");
- return 0;
- }
- pid->hide_pid = option;
- break;
- default:
- pr_err("proc: unrecognized mount option \"%s\" "
- "or missing value\n", p);
- return 0;
+ int token;
+
+ args[0].to = args[0].from = NULL;
+ token = match_token(opt, tokens, args);
+ switch (token) {
+ case Opt_gid:
+ if (match_int(&args[0], &ctx->gid))
+ return -EINVAL;
+ break;
+
+ case Opt_hidepid:
+ if (match_int(&args[0], &ctx->hidepid))
+ return -EINVAL;
+ if (ctx->hidepid < HIDEPID_OFF ||
+ ctx->hidepid > HIDEPID_INVISIBLE) {
+ pr_err("proc: hidepid value must be between 0 and 2.\n");
+ return -EINVAL;
}
+ break;
+
+ default:
+ pr_err("proc: unrecognized mount option \"%s\" or missing value\n",
+ opt);
+ return -EINVAL;
}
- return 1;
+ ctx->mask |= 1 << token;
+ return 0;
+}
+
+static void proc_set_options(struct super_block *s,
+ struct fs_context *fc,
+ struct pid_namespace *pid_ns,
+ struct user_namespace *user_ns)
+{
+ struct proc_fs_context *ctx = fc->fs_private;
+
+ if (ctx->mask & (1 << Opt_gid))
+ pid_ns->pid_gid = make_kgid(user_ns, ctx->gid);
+ if (ctx->mask & (1 << Opt_hidepid))
+ pid_ns->hide_pid = ctx->hidepid;
}
-static int proc_fill_super(struct super_block *s, void *data, size_t data_size, int silent)
+static int proc_fill_super(struct super_block *s, struct fs_context *fc)
{
- struct pid_namespace *ns = get_pid_ns(s->s_fs_info);
+ struct pid_namespace *pid_ns = get_pid_ns(s->s_fs_info);
struct inode *root_inode;
int ret;
- if (!proc_parse_options(data, ns))
- return -EINVAL;
+ proc_set_options(s, fc, pid_ns, current_user_ns());
/* User space would break if executables or devices appear on proc */
s->s_iflags |= SB_I_USERNS_VISIBLE | SB_I_NOEXEC | SB_I_NODEV;
@@ -103,7 +116,7 @@ static int proc_fill_super(struct super_block *s, void *data, size_t data_size,
* top of it
*/
s->s_stack_depth = FILESYSTEM_MAX_STACK_DEPTH;
-
+
pde_get(&proc_root);
root_inode = proc_get_inode(s, &proc_root);
if (!root_inode) {
@@ -124,30 +137,52 @@ static int proc_fill_super(struct super_block *s, void *data, size_t data_size,
return proc_setup_thread_self(s);
}
-int proc_remount(struct super_block *sb, int *flags,
- char *data, size_t data_size)
+int proc_reconfigure(struct super_block *sb, struct fs_context *fc)
{
struct pid_namespace *pid = sb->s_fs_info;
sync_filesystem(sb);
- return !proc_parse_options(data, pid);
+
+ if (fc)
+ proc_set_options(sb, fc, pid, current_user_ns());
+ return 0;
}
-static struct dentry *proc_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name,
- void *data, size_t data_size)
+static int proc_get_tree(struct fs_context *fc)
{
- struct pid_namespace *ns;
+ struct proc_fs_context *ctx = fc->fs_private;
- if (flags & SB_KERNMOUNT) {
- ns = data;
- data = NULL;
- } else {
- ns = task_active_pid_ns(current);
- }
+ fc->s_fs_info = ctx->pid_ns;
+ return vfs_get_super(fc, vfs_get_keyed_super, proc_fill_super);
+}
+
+static void proc_fs_context_free(struct fs_context *fc)
+{
+ struct proc_fs_context *ctx = fc->fs_private;
+
+ if (ctx->pid_ns)
+ put_pid_ns(ctx->pid_ns);
+ kfree(ctx);
+}
+
+static const struct fs_context_operations proc_fs_context_ops = {
+ .free = proc_fs_context_free,
+ .parse_option = proc_parse_option,
+ .get_tree = proc_get_tree,
+};
- return mount_ns(fs_type, flags, data, data_size, ns, ns->user_ns,
- proc_fill_super);
+static int proc_init_fs_context(struct fs_context *fc, struct dentry *reference)
+{
+ struct proc_fs_context *ctx;
+
+ ctx = kzalloc(sizeof(struct proc_fs_context), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->pid_ns = get_pid_ns(task_active_pid_ns(current));
+ fc->fs_private = ctx;
+ fc->ops = &proc_fs_context_ops;
+ return 0;
}
static void proc_kill_sb(struct super_block *sb)
@@ -164,10 +199,10 @@ static void proc_kill_sb(struct super_block *sb)
}
static struct file_system_type proc_fs_type = {
- .name = "proc",
- .mount = proc_mount,
- .kill_sb = proc_kill_sb,
- .fs_flags = FS_USERNS_MOUNT,
+ .name = "proc",
+ .init_fs_context = proc_init_fs_context,
+ .kill_sb = proc_kill_sb,
+ .fs_flags = FS_USERNS_MOUNT,
};
void __init proc_root_init(void)
@@ -205,7 +240,7 @@ static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentr
{
if (!proc_pid_lookup(dir, dentry, flags))
return NULL;
-
+
return proc_lookup(dir, dentry, flags);
}
@@ -259,9 +294,31 @@ struct proc_dir_entry proc_root = {
int pid_ns_prepare_proc(struct pid_namespace *ns)
{
+ struct proc_fs_context *ctx;
+ struct fs_context *fc;
struct vfsmount *mnt;
+ int ret;
+
+ fc = vfs_new_fs_context(&proc_fs_type, NULL, 0,
+ FS_CONTEXT_FOR_KERNEL_MOUNT);
+ if (IS_ERR(fc))
+ return PTR_ERR(fc);
+
+ ctx = fc->fs_private;
+ if (ctx->pid_ns != ns) {
+ put_pid_ns(ctx->pid_ns);
+ get_pid_ns(ns);
+ ctx->pid_ns = ns;
+ }
+
+ ret = vfs_get_tree(fc);
+ if (ret < 0) {
+ put_fs_context(fc);
+ return ret;
+ }
- mnt = kern_mount_data(&proc_fs_type, ns, 0);
+ mnt = vfs_create_mount(fc, 0);
+ put_fs_context(fc);
if (IS_ERR(mnt))
return PTR_ERR(mnt);
next prev parent reply other threads:[~2018-05-25 0:06 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-25 0:05 [PATCH 00/32] VFS: Introduce filesystem context [ver #8] David Howells
2018-05-25 0:05 ` [PATCH 01/32] VFS: Suppress MS_* flag defs within the kernel unless explicitly enabled " David Howells
2018-05-25 0:05 ` [PATCH 02/32] vfs: Provide documentation for new mount API " David Howells
2018-05-25 0:05 ` [PATCH 03/32] VFS: Introduce the basic header for the new mount API's filesystem context " David Howells
2018-05-31 23:11 ` Al Viro
2018-05-31 23:13 ` Al Viro
2018-05-25 0:05 ` [PATCH 04/32] VFS: Add LSM hooks for the new mount API " David Howells
2018-05-25 0:05 ` [PATCH 05/32] selinux: Implement the new mount API LSM hooks " David Howells
2018-05-25 0:06 ` [PATCH 06/32] smack: Implement filesystem context security " David Howells
2018-05-25 0:06 ` [PATCH 07/32] apparmor: Implement security hooks for the new mount API " David Howells
2018-05-25 0:06 ` [PATCH 08/32] tomoyo: " David Howells
2018-05-25 0:06 ` [PATCH 09/32] VFS: Require specification of size of mount data for internal mounts " David Howells
2018-05-25 0:06 ` [PATCH 10/32] VFS: Implement a filesystem superblock creation/configuration context " David Howells
2018-06-07 19:50 ` Miklos Szeredi
2018-07-03 18:33 ` Eric Biggers
2018-07-03 21:53 ` David Howells
2018-07-03 21:58 ` Al Viro
2018-07-03 22:06 ` David Howells
2018-05-25 0:06 ` [PATCH 11/32] VFS: Remove unused code after filesystem context changes " David Howells
2018-05-25 0:06 ` [PATCH 12/32] procfs: Move proc_fill_super() to fs/proc/root.c " David Howells
2018-05-25 0:06 ` David Howells [this message]
2018-05-25 0:06 ` [PATCH 14/32] ipc: Convert mqueue fs to fs_context " David Howells
2018-05-25 0:07 ` [PATCH 15/32] cpuset: Use " David Howells
2018-05-25 0:07 ` [PATCH 16/32] kernfs, sysfs, cgroup, intel_rdt: Support " David Howells
2018-06-21 18:47 ` [16/32] " Andrei Vagin
2018-06-22 12:52 ` David Howells
2018-06-22 15:30 ` Andrei Vagin
2018-06-22 16:57 ` Andrei Vagin
2018-06-23 23:34 ` David Howells
2018-05-25 0:07 ` [PATCH 17/32] hugetlbfs: Convert to " David Howells
2018-05-25 0:07 ` [PATCH 18/32] VFS: Remove kern_mount_data() " David Howells
2018-05-25 0:07 ` [PATCH 19/32] VFS: Implement fsopen() to prepare for a mount " David Howells
2018-05-31 21:25 ` Al Viro
2018-05-25 0:07 ` [PATCH 20/32] vfs: Make close() unmount the attached mount if so flagged " David Howells
2018-05-31 19:19 ` Al Viro
2018-05-31 19:26 ` Al Viro
2018-06-01 1:52 ` Al Viro
2018-06-01 3:18 ` Al Viro
2018-06-01 5:16 ` Al Viro
2018-05-25 0:07 ` [PATCH 21/32] VFS: Implement fsmount() to effect a pre-configured mount " David Howells
2018-06-04 15:05 ` Arnd Bergmann
2018-06-04 15:24 ` David Howells
2018-05-25 0:07 ` [PATCH 22/32] vfs: Provide an fspick() system call " David Howells
2018-05-25 0:07 ` [PATCH 23/32] VFS: Implement logging through fs_context " David Howells
2018-05-25 1:48 ` Joe Perches
2018-05-25 0:07 ` [PATCH 24/32] vfs: Add some logging to the core users of the fs_context log " David Howells
2018-05-25 0:08 ` [PATCH 25/32] afs: Add fs_context support " David Howells
2018-05-25 0:08 ` [PATCH 26/32] afs: Use fs_context to pass parameters over automount " David Howells
2018-06-07 1:58 ` Goldwyn Rodrigues
2018-06-07 20:45 ` David Howells
2018-05-25 0:08 ` [PATCH 27/32] vfs: Use a 'struct fd_cookie *' type for light fd handling " David Howells
2018-05-25 0:08 ` [PATCH 28/32] vfs: Store the fd_cookie in nameidata, not the dfd int " David Howells
2018-05-25 0:08 ` [PATCH 29/32] vfs: Don't mix FMODE_* flags with O_* flags " David Howells
2018-05-25 0:08 ` [PATCH 30/32] vfs: Allow cloning of a mount tree with open(O_PATH|O_CLONE_MOUNT) " David Howells
2018-06-01 6:26 ` Christoph Hellwig
2018-06-01 6:39 ` Al Viro
2018-06-01 8:27 ` David Howells
2018-06-02 3:09 ` Al Viro
2018-06-02 3:42 ` Al Viro
2018-06-02 4:04 ` Al Viro
2018-06-02 15:45 ` David Howells
2018-06-02 17:49 ` Al Viro
2018-06-03 0:55 ` [PATCH][RFC] open_tree(2) (was Re: [PATCH 30/32] vfs: Allow cloning of a mount tree with open(O_PATH|O_CLONE_MOUNT) [ver #8]) Al Viro
2018-06-04 10:34 ` Miklos Szeredi
2018-06-04 15:52 ` Al Viro
2018-06-04 15:59 ` Al Viro
2018-06-04 19:27 ` Miklos Szeredi
2018-06-04 15:27 ` David Howells
2018-06-04 17:16 ` Matthew Wilcox
2018-06-04 17:35 ` Al Viro
2018-06-04 19:38 ` Miklos Szeredi
2018-06-01 8:02 ` [PATCH 30/32] vfs: Allow cloning of a mount tree with open(O_PATH|O_CLONE_MOUNT) [ver #8] Amir Goldstein
2018-06-01 8:42 ` David Howells
2018-05-25 0:08 ` [PATCH 31/32] [RFC] fs: Add a move_mount() system call " David Howells
2018-05-31 21:20 ` Al Viro
2018-05-25 0:08 ` [PATCH 32/32] [RFC] fsinfo: Add a system call to allow querying of filesystem information " David Howells
2018-06-04 13:10 ` Arnd Bergmann
2018-06-04 15:01 ` David Howells
2018-06-04 16:00 ` Arnd Bergmann
2018-06-04 19:03 ` David Howells
2018-06-04 20:45 ` Arnd Bergmann
2018-05-31 20:56 ` Test program for move_mount() David Howells
2018-05-31 20:57 ` fsinfo test program David Howells
2018-06-15 4:18 ` [PATCH 00/32] VFS: Introduce filesystem context [ver #8] Eric W. Biederman
2018-06-18 20:30 ` David Howells
2018-06-18 21:33 ` Eric W. Biederman
2018-06-18 23:33 ` Theodore Y. Ts'o
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