procfs: switch /proc/self away from proc_dir_entry
Just have it pinned in dcache all along and let procfs ->kill_sb()
drop it before kill_anon_super().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 69078c7..593e7c5 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2794,7 +2794,7 @@
return iter;
}
-#define TGID_OFFSET (FIRST_PROCESS_ENTRY)
+#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 1)
static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
struct tgid_iter iter)
@@ -2817,13 +2817,21 @@
struct tgid_iter iter;
struct pid_namespace *ns;
filldir_t __filldir;
+ loff_t pos = filp->f_pos;
- if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
+ if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
goto out;
- ns = filp->f_dentry->d_sb->s_fs_info;
+ if (pos == TGID_OFFSET - 1) {
+ if (proc_fill_cache(filp, dirent, filldir, "self", 4,
+ NULL, NULL, NULL) < 0)
+ goto out;
+ iter.tgid = 0;
+ } else {
+ iter.tgid = pos - TGID_OFFSET;
+ }
iter.task = NULL;
- iter.tgid = filp->f_pos - TGID_OFFSET;
+ ns = filp->f_dentry->d_sb->s_fs_info;
for (iter = next_tgid(ns, iter);
iter.task;
iter.tgid += 1, iter = next_tgid(ns, iter)) {
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 869116c..908e974 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -506,5 +506,5 @@
return -ENOMEM;
}
- return 0;
+ return proc_setup_self(s);
}
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 85ff3a4..9c93a53 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -205,3 +205,4 @@
extern const struct inode_operations proc_ns_dir_inode_operations;
extern const struct file_operations proc_ns_dir_operations;
+extern int proc_setup_self(struct super_block *);
diff --git a/fs/proc/root.c b/fs/proc/root.c
index c6e9fac..20834b3 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -137,6 +137,8 @@
struct pid_namespace *ns;
ns = (struct pid_namespace *)sb->s_fs_info;
+ if (ns->proc_self)
+ dput(ns->proc_self);
kill_anon_super(sb);
put_pid_ns(ns);
}
diff --git a/fs/proc/self.c b/fs/proc/self.c
index d8a0252..21940d8 100644
--- a/fs/proc/self.c
+++ b/fs/proc/self.c
@@ -1,6 +1,7 @@
-#include <linux/proc_fs.h>
#include <linux/sched.h>
#include <linux/namei.h>
+#include <linux/pid_namespace.h>
+#include "internal.h"
/*
* /proc/self:
@@ -48,12 +49,43 @@
.put_link = proc_self_put_link,
};
+static unsigned self_inum;
+
+int proc_setup_self(struct super_block *s)
+{
+ struct inode *root_inode = s->s_root->d_inode;
+ struct pid_namespace *ns = s->s_fs_info;
+ struct dentry *self;
+
+ mutex_lock(&root_inode->i_mutex);
+ self = d_alloc_name(s->s_root, "self");
+ if (self) {
+ struct inode *inode = new_inode_pseudo(s);
+ if (inode) {
+ inode->i_ino = self_inum;
+ inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+ inode->i_mode = S_IFLNK | S_IRWXUGO;
+ inode->i_uid = GLOBAL_ROOT_UID;
+ inode->i_gid = GLOBAL_ROOT_GID;
+ inode->i_op = &proc_self_inode_operations;
+ d_add(self, inode);
+ } else {
+ dput(self);
+ self = ERR_PTR(-ENOMEM);
+ }
+ } else {
+ self = ERR_PTR(-ENOMEM);
+ }
+ mutex_unlock(&root_inode->i_mutex);
+ if (IS_ERR(self)) {
+ pr_err("proc_fill_super: can't allocate /proc/self\n");
+ return PTR_ERR(self);
+ }
+ ns->proc_self = self;
+ return 0;
+}
+
void __init proc_self_init(void)
{
- struct proc_dir_entry *proc_self_symlink;
- umode_t mode;
-
- mode = S_IFLNK | S_IRWXUGO;
- proc_self_symlink = proc_create("self", mode, NULL, NULL );
- proc_self_symlink->proc_iops = &proc_self_inode_operations;
+ proc_alloc_inum(&self_inum);
}
