Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux...

[linux-2.6] / fs / proc / base.c

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 634355e169869c3369959acbe5261542bb4cacb6..6afff725a8c922b08bb3b6bbd52bf044ecc42e6c 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>
@@ -103,6 +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,
@@ -143,6 +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,
@@ -200,6 +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
@@ -293,16 +297,20 @@ static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsm
 
        files = get_files_struct(task);
        if (files) {
-               rcu_read_lock();
+               /*
+                * We are not taking a ref to the file structure, so we must
+                * hold ->file_lock.
+                */
+               spin_lock(&files->file_lock);
                file = fcheck_files(files, fd);
                if (file) {
                        *mnt = mntget(file->f_vfsmnt);
                        *dentry = dget(file->f_dentry);
-                       rcu_read_unlock();
+                       spin_unlock(&files->file_lock);
                        put_files_struct(files);
                        return 0;
                }
-               rcu_read_unlock();
+               spin_unlock(&files->file_lock);
                put_files_struct(files);
        }
        return -ENOENT;
@@ -530,12 +538,15 @@ 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);
@@ -545,11 +556,11 @@ 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))
@@ -560,7 +571,7 @@ exit:
        dput(base);
        mntput(our_vfsmnt);
        dput(root);
-       mntput(mnt);
+       mntput(vfsmnt);
        return res;
 out:
        spin_unlock(&vfsmount_lock);
@@ -731,6 +742,38 @@ static struct file_operations proc_mounts_operations = {
        .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;
+               struct namespace *namespace;
+               task_lock(task);
+               namespace = task->namespace;
+               if (namespace)
+                       get_namespace(namespace);
+               task_unlock(task);
+
+               if (namespace)
+                       m->private = namespace;
+               else {
+                       seq_release(inode, file);
+                       ret = -EINVAL;
+               }
+       }
+       return ret;
+}
+
+static struct file_operations proc_mountstats_operations = {
+       .open           = mountstats_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = mounts_release,
+};
+
 #define PROC_BLOCK_SIZE        (3*1024)                /* 4K page size but our output routines use some slack for overruns */
 
 static ssize_t proc_info_read(struct file * file, char __user * buf,
@@ -976,8 +1019,8 @@ static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
        if (current != task)
                return -EPERM;
 
-       if (count > PAGE_SIZE)
-               count = PAGE_SIZE;
+       if (count >= PAGE_SIZE)
+               count = PAGE_SIZE - 1;
 
        if (*ppos != 0) {
                /* No partial writes. */
@@ -990,6 +1033,7 @@ static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
        if (copy_from_user(page, buf, count))
                goto out_free_page;
 
+       page[count] = '\0';
        loginuid = simple_strtoul(page, &tmp, 10);
        if (tmp == page) {
                length = -EINVAL;
@@ -1484,7 +1528,12 @@ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry,
        if (!files)
                goto out_unlock;
        inode->i_mode = S_IFLNK;
-       rcu_read_lock();
+
+       /*
+        * We are not taking a ref to the file structure, so we must
+        * hold ->file_lock.
+        */
+       spin_lock(&files->file_lock);
        file = fcheck_files(files, fd);
        if (!file)
                goto out_unlock2;
@@ -1492,7 +1541,7 @@ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry,
                inode->i_mode |= S_IRUSR | S_IXUSR;
        if (file->f_mode & 2)
                inode->i_mode |= S_IWUSR | S_IXUSR;
-       rcu_read_unlock();
+       spin_unlock(&files->file_lock);
        put_files_struct(files);
        inode->i_op = &proc_pid_link_inode_operations;
        inode->i_size = 64;
@@ -1502,7 +1551,7 @@ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry,
        return NULL;
 
 out_unlock2:
-       rcu_read_unlock();
+       spin_unlock(&files->file_lock);
        put_files_struct(files);
 out_unlock:
        iput(inode);
@@ -1729,6 +1778,10 @@ 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;