1 files changed, 26 insertions, 46 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 0c9de19a1633..e0afd326b688 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -146,15 +146,22 @@ static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
 	return count;
 }
 
-static struct fs_struct *get_fs_struct(struct task_struct *task)
+static int get_fs_path(struct task_struct *task, struct path *path, bool root)
 {
 	struct fs_struct *fs;
+	int result = -ENOENT;
+
 	task_lock(task);
 	fs = task->fs;
-	if(fs)
-		atomic_inc(&fs->count);
+	if (fs) {
+		read_lock(&fs->lock);
+		*path = root ? fs->root : fs->pwd;
+		path_get(path);
+		read_unlock(&fs->lock);
+		result = 0;
+	}
 	task_unlock(task);
-	return fs;
+	return result;
 }
 
 static int get_nr_threads(struct task_struct *tsk)
@@ -172,42 +179,24 @@ static int get_nr_threads(struct task_struct *tsk)
 static int proc_cwd_link(struct inode *inode, struct path *path)
 {
 	struct task_struct *task = get_proc_task(inode);
-	struct fs_struct *fs = NULL;
 	int result = -ENOENT;
 
 	if (task) {
-		fs = get_fs_struct(task);
+		result = get_fs_path(task, path, 0);
 		put_task_struct(task);
 	}
-	if (fs) {
-		read_lock(&fs->lock);
-		*path = fs->pwd;
-		path_get(&fs->pwd);
-		read_unlock(&fs->lock);
-		result = 0;
-		put_fs_struct(fs);
-	}
 	return result;
 }
 
 static int proc_root_link(struct inode *inode, struct path *path)
 {
 	struct task_struct *task = get_proc_task(inode);
-	struct fs_struct *fs = NULL;
 	int result = -ENOENT;
 
 	if (task) {
-		fs = get_fs_struct(task);
+		result = get_fs_path(task, path, 1);
 		put_task_struct(task);
 	}
-	if (fs) {
-		read_lock(&fs->lock);
-		*path = fs->root;
-		path_get(&fs->root);
-		read_unlock(&fs->lock);
-		result = 0;
-		put_fs_struct(fs);
-	}
 	return result;
 }
 
@@ -596,7 +585,6 @@ static int mounts_open_common(struct inode *inode, struct file *file,
 	struct task_struct *task = get_proc_task(inode);
 	struct nsproxy *nsp;
 	struct mnt_namespace *ns = NULL;
-	struct fs_struct *fs = NULL;
 	struct path root;
 	struct proc_mounts *p;
 	int ret = -EINVAL;
@@ -610,22 +598,16 @@ static int mounts_open_common(struct inode *inode, struct file *file,
 				get_mnt_ns(ns);
 		}
 		rcu_read_unlock();
-		if (ns)
-			fs = get_fs_struct(task);
+		if (ns && get_fs_path(task, &root, 1) == 0)
+			ret = 0;
 		put_task_struct(task);
 	}
 
 	if (!ns)
 		goto err;
-	if (!fs)
+	if (ret)
 		goto err_put_ns;
 
-	read_lock(&fs->lock);
-	root = fs->root;
-	path_get(&root);
-	read_unlock(&fs->lock);
-	put_fs_struct(fs);
-
 	ret = -ENOMEM;
 	p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
 	if (!p)
@@ -1545,7 +1527,7 @@ static int pid_delete_dentry(struct dentry * dentry)
 	return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
 }
 
-static struct dentry_operations pid_dentry_operations =
+static const struct dentry_operations pid_dentry_operations =
 {
 	.d_revalidate	= pid_revalidate,
 	.d_delete	= pid_delete_dentry,
@@ -1717,7 +1699,7 @@ static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
 	return 0;
 }
 
-static struct dentry_operations tid_fd_dentry_operations =
+static const struct dentry_operations tid_fd_dentry_operations =
 {
 	.d_revalidate	= tid_fd_revalidate,
 	.d_delete	= pid_delete_dentry,
@@ -2339,7 +2321,7 @@ static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd)
 	return 0;
 }
 
-static struct dentry_operations proc_base_dentry_operations =
+static const struct dentry_operations proc_base_dentry_operations =
 {
 	.d_revalidate	= proc_base_revalidate,
 	.d_delete	= pid_delete_dentry,
@@ -3066,7 +3048,6 @@ static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldi
 	int retval = -ENOENT;
 	ino_t ino;
 	int tid;
-	unsigned long pos = filp->f_pos;  /* avoiding "long long" filp->f_pos */
 	struct pid_namespace *ns;
 
 	task = get_proc_task(inode);
@@ -3083,18 +3064,18 @@ static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldi
 		goto out_no_task;
 	retval = 0;
 
-	switch (pos) {
+	switch ((unsigned long)filp->f_pos) {
 	case 0:
 		ino = inode->i_ino;
-		if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0)
+		if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
 			goto out;
-		pos++;
+		filp->f_pos++;
 		/* fall through */
 	case 1:
 		ino = parent_ino(dentry);
-		if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0)
+		if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
 			goto out;
-		pos++;
+		filp->f_pos++;
 		/* fall through */
 	}
 
@@ -3104,9 +3085,9 @@ static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldi
 	ns = filp->f_dentry->d_sb->s_fs_info;
 	tid = (int)filp->f_version;
 	filp->f_version = 0;
-	for (task = first_tid(leader, tid, pos - 2, ns);
+	for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
 	     task;
-	     task = next_tid(task), pos++) {
+	     task = next_tid(task), filp->f_pos++) {
 		tid = task_pid_nr_ns(task, ns);
 		if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
 			/* returning this tgid failed, save it as the first
@@ -3117,7 +3098,6 @@ static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldi
 		}
 	}
 out:
-	filp->f_pos = pos;
 	put_task_struct(leader);
 out_no_task:
 	return retval;