Merge master.kernel.org:/pub/scm/linux/kernel/git/brodo/pcmcia-2.6

[cascardo/linux.git] / fs / proc / base.c

diff --git a/fs/proc/base.c b/fs/proc/base.c
index a170450..a3a3eec 100644 (file)
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -55,6 +55,7 @@
 #include <linux/proc_fs.h>
 #include <linux/stat.h>
 #include <linux/init.h>
+#include <linux/capability.h>
 #include <linux/file.h>
 #include <linux/string.h>
 #include <linux/seq_file.h>
@@ -70,6 +71,7 @@
 #include <linux/seccomp.h>
 #include <linux/cpuset.h>
 #include <linux/audit.h>
+#include <linux/poll.h>
 #include "internal.h"
 
 /*
@@ -102,6 +104,7 @@ enum pid_directory_inos {
        PROC_TGID_MAPS,
        PROC_TGID_NUMA_MAPS,
        PROC_TGID_MOUNTS,
+       PROC_TGID_MOUNTSTATS,
        PROC_TGID_WCHAN,
 #ifdef CONFIG_MMU
        PROC_TGID_SMAPS,
@@ -142,6 +145,7 @@ enum pid_directory_inos {
        PROC_TID_MAPS,
        PROC_TID_NUMA_MAPS,
        PROC_TID_MOUNTS,
+       PROC_TID_MOUNTSTATS,
        PROC_TID_WCHAN,
 #ifdef CONFIG_MMU
        PROC_TID_SMAPS,
@@ -199,6 +203,7 @@ static struct pid_entry tgid_base_stuff[] = {
        E(PROC_TGID_ROOT,      "root",    S_IFLNK|S_IRWXUGO),
        E(PROC_TGID_EXE,       "exe",     S_IFLNK|S_IRWXUGO),
        E(PROC_TGID_MOUNTS,    "mounts",  S_IFREG|S_IRUGO),
+       E(PROC_TGID_MOUNTSTATS, "mountstats", S_IFREG|S_IRUSR),
 #ifdef CONFIG_MMU
        E(PROC_TGID_SMAPS,     "smaps",   S_IFREG|S_IRUGO),
 #endif
@@ -529,12 +534,15 @@ static int proc_oom_score(struct task_struct *task, char *buffer)
 
 /* If the process being read is separated by chroot from the reading process,
  * don't let the reader access the threads.
+ *
+ * note: this does dput(root) and mntput(vfsmnt) on exit.
  */
 static int proc_check_chroot(struct dentry *root, struct vfsmount *vfsmnt)
 {
        struct dentry *de, *base;
        struct vfsmount *our_vfsmnt, *mnt;
        int res = 0;
+
        read_lock(&current->fs->lock);
        our_vfsmnt = mntget(current->fs->rootmnt);
        base = dget(current->fs->root);
@@ -544,11 +552,11 @@ static int proc_check_chroot(struct dentry *root, struct vfsmount *vfsmnt)
        de = root;
        mnt = vfsmnt;
 
-       while (vfsmnt != our_vfsmnt) {
-               if (vfsmnt == vfsmnt->mnt_parent)
+       while (mnt != our_vfsmnt) {
+               if (mnt == mnt->mnt_parent)
                        goto out;
-               de = vfsmnt->mnt_mountpoint;
-               vfsmnt = vfsmnt->mnt_parent;
+               de = mnt->mnt_mountpoint;
+               mnt = mnt->mnt_parent;
        }
 
        if (!is_subdir(de, base))
@@ -559,7 +567,7 @@ exit:
        dput(base);
        mntput(our_vfsmnt);
        dput(root);
-       mntput(mnt);
+       mntput(vfsmnt);
        return res;
 out:
        spin_unlock(&vfsmount_lock);
@@ -660,10 +668,81 @@ static struct file_operations proc_smaps_operations = {
 #endif
 
 extern struct seq_operations mounts_op;
+struct proc_mounts {
+       struct seq_file m;
+       int event;
+};
+
 static int mounts_open(struct inode *inode, struct file *file)
 {
        struct task_struct *task = proc_task(inode);
-       int ret = seq_open(file, &mounts_op);
+       struct namespace *namespace;
+       struct proc_mounts *p;
+       int ret = -EINVAL;
+
+       task_lock(task);
+       namespace = task->namespace;
+       if (namespace)
+               get_namespace(namespace);
+       task_unlock(task);
+
+       if (namespace) {
+               ret = -ENOMEM;
+               p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
+               if (p) {
+                       file->private_data = &p->m;
+                       ret = seq_open(file, &mounts_op);
+                       if (!ret) {
+                               p->m.private = namespace;
+                               p->event = namespace->event;
+                               return 0;
+                       }
+                       kfree(p);
+               }
+               put_namespace(namespace);
+       }
+       return ret;
+}
+
+static int mounts_release(struct inode *inode, struct file *file)
+{
+       struct seq_file *m = file->private_data;
+       struct namespace *namespace = m->private;
+       put_namespace(namespace);
+       return seq_release(inode, file);
+}
+
+static unsigned mounts_poll(struct file *file, poll_table *wait)
+{
+       struct proc_mounts *p = file->private_data;
+       struct namespace *ns = p->m.private;
+       unsigned res = 0;
+
+       poll_wait(file, &ns->poll, wait);
+
+       spin_lock(&vfsmount_lock);
+       if (p->event != ns->event) {
+               p->event = ns->event;
+               res = POLLERR;
+       }
+       spin_unlock(&vfsmount_lock);
+
+       return res;
+}
+
+static struct file_operations proc_mounts_operations = {
+       .open           = mounts_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = mounts_release,
+       .poll           = mounts_poll,
+};
+
+extern struct seq_operations mountstats_op;
+static int mountstats_open(struct inode *inode, struct file *file)
+{
+       struct task_struct *task = proc_task(inode);
+       int ret = seq_open(file, &mountstats_op);
 
        if (!ret) {
                struct seq_file *m = file->private_data;
@@ -684,16 +763,8 @@ static int mounts_open(struct inode *inode, struct file *file)
        return ret;
 }
 
-static int mounts_release(struct inode *inode, struct file *file)
-{
-       struct seq_file *m = file->private_data;
-       struct namespace *namespace = m->private;
-       put_namespace(namespace);
-       return seq_release(inode, file);
-}
-
-static struct file_operations proc_mounts_operations = {
-       .open           = mounts_open,
+static struct file_operations proc_mountstats_operations = {
+       .open           = mountstats_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = mounts_release,
@@ -1697,6 +1768,10 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
                        inode->i_fop = &proc_smaps_operations;
                        break;
 #endif
+               case PROC_TID_MOUNTSTATS:
+               case PROC_TGID_MOUNTSTATS:
+                       inode->i_fop = &proc_mountstats_operations;
+                       break;
 #ifdef CONFIG_SECURITY
                case PROC_TID_ATTR:
                        inode->i_nlink = 2;