From: David Howells <dhowells@redhat.com>
To: viro@zeniv.linux.org.uk
Cc: torvalds@linux-foundation.org, dhowells@redhat.com,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 17/33] proc: Add fs_context support to procfs [ver #11]
Date: Wed, 01 Aug 2018 16:26:01 +0100 [thread overview]
Message-ID: <153313716142.13253.11610581914208571409.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <153313703562.13253.5766498657900728120.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 | 209 +++++++++++++++++++++++++++++++++++-----------------
3 files changed, 141 insertions(+), 72 deletions(-)
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index c5e7bbf81e10..38155bec4a54 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -127,7 +127,7 @@ 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 bfe2bea2c71d..ea8c5468eafc 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -273,7 +273,7 @@ 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 15da85cefd3f..1d6e5bfa30cc 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -19,74 +19,98 @@
#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/fs_parser.h>
#include <linux/cred.h>
#include <linux/magic.h>
+#include <linux/slab.h>
#include "internal.h"
-enum {
- Opt_gid, Opt_hidepid, Opt_err,
+struct proc_fs_context {
+ struct pid_namespace *pid_ns;
+ unsigned long mask;
+ int hidepid;
+ int gid;
};
-static const match_table_t tokens = {
- {Opt_hidepid, "hidepid=%u"},
- {Opt_gid, "gid=%u"},
- {Opt_err, NULL},
+enum proc_param {
+ Opt_gid,
+ Opt_hidepid,
+ nr__proc_params
};
-static int proc_parse_options(char *options, struct pid_namespace *pid)
+static const struct fs_parameter_spec proc_param_specs[nr__proc_params] = {
+ [Opt_gid] = { fs_param_is_u32 },
+ [Opt_hidepid] = { fs_param_is_u32 },
+};
+
+static const struct constant_table proc_param_keys[] = {
+ { "gid", Opt_gid },
+ { "hidepid", Opt_hidepid },
+};
+
+static const struct fs_parameter_description proc_fs_parameters = {
+ .name = "proc",
+ .nr_params = nr__proc_params,
+ .nr_keys = ARRAY_SIZE(proc_param_keys),
+ .keys = proc_param_keys,
+ .specs = proc_param_specs,
+ .no_source = true,
+};
+
+static int proc_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
- char *p;
- 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;
- }
+ struct proc_fs_context *ctx = fc->fs_private;
+ struct fs_parse_result result;
+ int ret;
+
+ ret = fs_parse(fc, &proc_fs_parameters, param, &result);
+ if (ret <= 0)
+ return ret;
+
+ switch (result.key) {
+ case Opt_gid:
+ ctx->gid = result.uint_32;
+ break;
+
+ case Opt_hidepid:
+ ctx->hidepid = result.uint_32;
+ if (ctx->hidepid < HIDEPID_OFF ||
+ ctx->hidepid > HIDEPID_INVISIBLE)
+ return invalf(fc, "proc: hidepid value must be between 0 and 2.\n");
+ break;
+
+ default:
+ return -EINVAL;
}
- return 1;
+ ctx->mask |= 1 << result.key;
+ return 0;
}
-static int proc_fill_super(struct super_block *s, void *data, size_t data_size, int silent)
+static void proc_apply_options(struct super_block *s,
+ struct fs_context *fc,
+ struct pid_namespace *pid_ns,
+ struct user_namespace *user_ns)
{
- struct pid_namespace *ns = get_pid_ns(s->s_fs_info);
+ 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, struct fs_context *fc)
+{
+ 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_apply_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 +127,7 @@ 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 +148,52 @@ 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_apply_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);
+}
- return mount_ns(fs_type, flags, data, data_size, ns, ns->user_ns,
- 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_param = proc_parse_param,
+ .get_tree = proc_get_tree,
+};
+
+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 +210,11 @@ 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,
+ .parameters = &proc_fs_parameters,
+ .kill_sb = proc_kill_sb,
+ .fs_flags = FS_USERNS_MOUNT,
};
void __init proc_root_init(void)
@@ -205,7 +252,7 @@ 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);
}
@@ -258,9 +305,31 @@ 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:[~2018-08-01 15:26 UTC|newest]
Thread overview: 116+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-01 15:23 [PATCH 00/33] VFS: Introduce filesystem context [ver #11] David Howells
2018-08-01 15:24 ` [PATCH 01/33] vfs: syscall: Add open_tree(2) to reference or clone a mount " David Howells
2018-08-02 17:31 ` Alan Jenkins
2018-08-02 21:29 ` Al Viro
2018-08-02 21:51 ` David Howells
2018-08-02 23:46 ` Alan Jenkins
2018-08-01 15:24 ` [PATCH 02/33] vfs: syscall: Add move_mount(2) to move mounts around " David Howells
2018-08-01 15:24 ` [PATCH 03/33] teach move_mount(2) to work with OPEN_TREE_CLONE " David Howells
2018-10-12 14:25 ` Alan Jenkins
2018-08-01 15:24 ` [PATCH 04/33] vfs: Suppress MS_* flag defs within the kernel unless explicitly enabled " David Howells
2018-08-01 15:24 ` [PATCH 05/33] vfs: Introduce the basic header for the new mount API's filesystem context " David Howells
2018-08-01 15:24 ` [PATCH 06/33] vfs: Introduce logging functions " David Howells
2018-08-01 15:24 ` [PATCH 07/33] vfs: Add configuration parser helpers " David Howells
2018-08-01 15:24 ` [PATCH 08/33] vfs: Add LSM hooks for the new mount API " David Howells
2018-08-01 20:50 ` James Morris
2018-08-01 22:53 ` David Howells
2018-08-01 15:25 ` [PATCH 09/33] selinux: Implement the new mount API LSM hooks " David Howells
2018-08-01 15:25 ` [PATCH 10/33] smack: Implement filesystem context security " David Howells
2018-08-01 15:25 ` [PATCH 11/33] apparmor: Implement security hooks for the new mount API " David Howells
2018-08-01 15:25 ` [PATCH 12/33] tomoyo: " David Howells
2018-08-01 15:25 ` [PATCH 13/33] vfs: Separate changing mount flags full remount " David Howells
2018-08-01 15:25 ` [PATCH 14/33] vfs: Implement a filesystem superblock creation/configuration context " David Howells
2018-09-11 17:46 ` Guenter Roeck
2018-09-11 21:52 ` David Howells
2018-09-11 22:07 ` Guenter Roeck
2018-09-11 23:17 ` David Howells
2018-09-11 23:54 ` Guenter Roeck
2018-09-18 9:07 ` Sergey Senozhatsky
2018-09-18 9:40 ` Sergey Senozhatsky
2018-09-18 14:06 ` Guenter Roeck
2018-09-19 1:12 ` Sergey Senozhatsky
2018-09-19 1:26 ` Sergey Senozhatsky
2018-09-18 15:34 ` David Howells
2018-09-18 16:39 ` David Howells
2018-09-19 1:15 ` Sergey Senozhatsky
2018-09-18 17:43 ` David Howells
2018-09-18 9:54 ` Sergey Senozhatsky
2018-09-18 15:28 ` David Howells
2018-08-01 15:25 ` [PATCH 15/33] vfs: Remove unused code after filesystem context changes " David Howells
2018-08-01 15:25 ` [PATCH 16/33] procfs: Move proc_fill_super() to fs/proc/root.c " David Howells
2018-08-01 15:26 ` David Howells [this message]
2018-08-01 15:26 ` [PATCH 18/33] ipc: Convert mqueue fs to fs_context " David Howells
2018-08-01 15:26 ` [PATCH 19/33] cpuset: Use " David Howells
2018-08-01 15:26 ` [PATCH 20/33] kernfs, sysfs, cgroup, intel_rdt: Support " David Howells
2018-08-01 15:26 ` [PATCH 21/33] hugetlbfs: Convert to " David Howells
2018-08-01 15:26 ` [PATCH 22/33] vfs: Remove kern_mount_data() " David Howells
2018-08-01 15:26 ` [PATCH 23/33] vfs: Provide documentation for new mount API " David Howells
2018-08-01 15:26 ` [PATCH 24/33] Make anon_inodes unconditional " David Howells
2018-08-01 15:26 ` [PATCH 25/33] vfs: syscall: Add fsopen() to prepare for superblock creation " David Howells
2018-08-01 15:27 ` [PATCH 26/33] vfs: Implement logging through fs_context " David Howells
2018-08-01 15:27 ` [PATCH 27/33] vfs: Add some logging to the core users of the fs_context log " David Howells
2018-08-01 15:27 ` [PATCH 28/33] vfs: syscall: Add fsconfig() for configuring and managing a context " David Howells
2018-08-06 17:28 ` Eric W. Biederman
2018-08-09 14:14 ` David Howells
2018-08-09 14:24 ` David Howells
2018-08-09 14:35 ` Miklos Szeredi
2018-08-09 15:32 ` Eric W. Biederman
2018-08-09 16:33 ` David Howells
2018-08-11 20:20 ` David Howells
2018-08-11 23:26 ` Andy Lutomirski
2018-08-01 15:27 ` [PATCH 29/33] vfs: syscall: Add fsmount() to create a mount for a superblock " David Howells
2018-08-01 15:27 ` [PATCH 30/33] vfs: syscall: Add fspick() to select a superblock for reconfiguration " David Howells
2018-08-24 14:51 ` Miklos Szeredi
2018-08-24 14:54 ` Andy Lutomirski
2018-08-01 15:27 ` [PATCH 31/33] afs: Add fs_context support " David Howells
2018-08-01 15:27 ` [PATCH 32/33] afs: Use fs_context to pass parameters over automount " David Howells
2018-08-01 15:27 ` [PATCH 33/33] vfs: Add a sample program for the new mount API " David Howells
2018-08-10 14:05 ` BUG: Mount ignores mount options Eric W. Biederman
2018-08-10 14:36 ` Andy Lutomirski
2018-08-10 15:17 ` Eric W. Biederman
2018-08-10 15:24 ` Al Viro
2018-08-10 15:11 ` Tetsuo Handa
2018-08-10 15:13 ` David Howells
2018-08-10 15:16 ` Al Viro
2018-08-11 1:05 ` Eric W. Biederman
2018-08-11 1:46 ` Theodore Y. Ts'o
2018-08-11 4:48 ` Eric W. Biederman
2018-08-11 17:47 ` Casey Schaufler
2018-08-15 4:03 ` Eric W. Biederman
2018-08-11 1:58 ` Al Viro
2018-08-11 2:17 ` Al Viro
2018-08-11 4:43 ` Eric W. Biederman
2018-08-13 12:54 ` Miklos Szeredi
2018-08-10 15:11 ` David Howells
2018-08-10 15:39 ` Theodore Y. Ts'o
2018-08-10 15:55 ` Casey Schaufler
2018-08-10 16:11 ` David Howells
2018-08-10 18:00 ` Eric W. Biederman
2018-08-10 15:53 ` David Howells
2018-08-10 16:14 ` Theodore Y. Ts'o
2018-08-10 20:06 ` Andy Lutomirski
2018-08-10 20:46 ` Theodore Y. Ts'o
2018-08-10 22:12 ` Darrick J. Wong
2018-08-10 23:54 ` Theodore Y. Ts'o
2018-08-11 0:38 ` Darrick J. Wong
2018-08-11 1:32 ` Eric W. Biederman
2018-08-13 16:35 ` Alan Cox
2018-08-13 16:48 ` Andy Lutomirski
2018-08-13 17:29 ` Al Viro
2018-08-13 19:00 ` James Morris
2018-08-13 19:20 ` Casey Schaufler
2018-08-15 23:29 ` Serge E. Hallyn
2018-08-11 0:28 ` Eric W. Biederman
2018-08-11 1:19 ` Eric W. Biederman
2018-08-11 7:29 ` David Howells
2018-08-11 16:31 ` Andy Lutomirski
2018-08-11 16:51 ` Al Viro
2018-08-15 16:31 ` Should we split the network filesystem setup into two phases? David Howells
2018-08-15 16:51 ` Andy Lutomirski
2018-08-16 3:51 ` Steve French
2018-08-16 5:06 ` Eric W. Biederman
2018-08-16 16:24 ` Steve French
2018-08-16 17:21 ` Eric W. Biederman
2018-08-16 17:23 ` Aurélien Aptel
2018-08-16 18:36 ` Steve French
2018-08-17 23:11 ` Al Viro
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