d_path: Make proc_get_link() use a struct path argument

proc_get_link() is always called with a dentry and a vfsmount from a struct
path.  Make proc_get_link() take it directly as an argument.

Signed-off-by: Jan Blunck <jblunck@suse.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 34 insertions, 42 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 080f1f6eda61..47338d92db51 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -153,7 +153,7 @@ static int get_nr_threads(struct task_struct *tsk)
         return count;
 }
 
-static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
+static int proc_cwd_link(struct inode *inode, struct path *path)
 {
         struct task_struct *task = get_proc_task(inode);
         struct fs_struct *fs = NULL;
@@ -165,8 +165,8 @@ static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfs
         }
         if (fs) {
                 read_lock(&fs->lock);
-                *mnt = mntget(fs->pwd.mnt);
-                *dentry = dget(fs->pwd.dentry);
+                *path = fs->pwd;
+                path_get(&fs->pwd);
                 read_unlock(&fs->lock);
                 result = 0;
                 put_fs_struct(fs);
@@ -174,7 +174,7 @@ static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfs
         return result;
 }
 
-static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
+static int proc_root_link(struct inode *inode, struct path *path)
 {
         struct task_struct *task = get_proc_task(inode);
         struct fs_struct *fs = NULL;
@@ -186,8 +186,8 @@ static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vf
         }
         if (fs) {
                 read_lock(&fs->lock);
-                *mnt = mntget(fs->root.mnt);
-                *dentry = dget(fs->root.dentry);
+                *path = fs->root;
+                path_get(&fs->root);
                 read_unlock(&fs->lock);
                 result = 0;
                 put_fs_struct(fs);
@@ -1170,34 +1170,30 @@ static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
         if (!proc_fd_access_allowed(inode))
                 goto out;
 
-        error = PROC_I(inode)->op.proc_get_link(inode, &nd->path.dentry,
-                                                &nd->path.mnt);
+        error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
         nd->last_type = LAST_BIND;
 out:
         return ERR_PTR(error);
 }
 
-static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt,
-                            char __user *buffer, int buflen)
+static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
 {
-        struct inode * inode;
         char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
-        char *path;
+        char *pathname;
         int len;
 
         if (!tmp)
                 return -ENOMEM;
 
-        inode = dentry->d_inode;
-        path = d_path(dentry, mnt, tmp, PAGE_SIZE);
-        len = PTR_ERR(path);
-        if (IS_ERR(path))
+        pathname = d_path(path->dentry, path->mnt, tmp, PAGE_SIZE);
+        len = PTR_ERR(pathname);
+        if (IS_ERR(pathname))
                 goto out;
-        len = tmp + PAGE_SIZE - 1 - path;
+        len = tmp + PAGE_SIZE - 1 - pathname;
 
         if (len > buflen)
                 len = buflen;
-        if (copy_to_user(buffer, path, len))
+        if (copy_to_user(buffer, pathname, len))
                 len = -EFAULT;
  out:
         free_page((unsigned long)tmp);
@@ -1208,20 +1204,18 @@ static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int b
 {
         int error = -EACCES;
         struct inode *inode = dentry->d_inode;
-        struct dentry *de;
-        struct vfsmount *mnt = NULL;
+        struct path path;
 
         /* Are we allowed to snoop on the tasks file descriptors? */
         if (!proc_fd_access_allowed(inode))
                 goto out;
 
-        error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt);
+        error = PROC_I(inode)->op.proc_get_link(inode, &path);
         if (error)
                 goto out;
 
-        error = do_proc_readlink(de, mnt, buffer, buflen);
-        dput(de);
-        mntput(mnt);
+        error = do_proc_readlink(&path, buffer, buflen);
+        path_put(&path);
 out:
         return error;
 }
@@ -1448,8 +1442,7 @@ out:
 
 #define PROC_FDINFO_MAX 64
 
-static int proc_fd_info(struct inode *inode, struct dentry **dentry,
-                        struct vfsmount **mnt, char *info)
+static int proc_fd_info(struct inode *inode, struct path *path, char *info)
 {
         struct task_struct *task = get_proc_task(inode);
         struct files_struct *files = NULL;
@@ -1468,10 +1461,10 @@ static int proc_fd_info(struct inode *inode, struct dentry **dentry,
                 spin_lock(&files->file_lock);
                 file = fcheck_files(files, fd);
                 if (file) {
-                        if (mnt)
-                                *mnt = mntget(file->f_path.mnt);
-                        if (dentry)
-                                *dentry = dget(file->f_path.dentry);
+                        if (path) {
+                                *path = file->f_path;
+                                path_get(&file->f_path);
+                        }
                         if (info)
                                 snprintf(info, PROC_FDINFO_MAX,
                                          "pos:\t%lli\n"
@@ -1488,10 +1481,9 @@ static int proc_fd_info(struct inode *inode, struct dentry **dentry,
         return -ENOENT;
 }
 
-static int proc_fd_link(struct inode *inode, struct dentry **dentry,
-                        struct vfsmount **mnt)
+static int proc_fd_link(struct inode *inode, struct path *path)
 {
-        return proc_fd_info(inode, dentry, mnt, NULL);
+        return proc_fd_info(inode, path, NULL);
 }
 
 static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
@@ -1685,7 +1677,7 @@ static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
                                       size_t len, loff_t *ppos)
 {
         char tmp[PROC_FDINFO_MAX];
-        int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, NULL, tmp);
+        int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
         if (!err)
                 err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
         return err;
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index ea496ffeabe7..1c81c8f1aeed 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -48,7 +48,7 @@ extern int maps_protect;
 
 extern void create_seq_entry(char *name, mode_t mode,
                                 const struct file_operations *f);
-extern int proc_exe_link(struct inode *, struct dentry **, struct vfsmount **);
+extern int proc_exe_link(struct inode *, struct path *);
 extern int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns,
                                 struct pid *pid, struct task_struct *task);
 extern int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns,
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index ae4d3f2c8cb2..4c4f99fb1bfc 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -75,7 +75,7 @@ int task_statm(struct mm_struct *mm, int *shared, int *text,
         return mm->total_vm;
 }
 
-int proc_exe_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
+int proc_exe_link(struct inode *inode, struct path *path)
 {
         struct vm_area_struct * vma;
         int result = -ENOENT;
@@ -98,8 +98,8 @@ int proc_exe_link(struct inode *inode, struct dentry **dentry, struct vfsmount *
         }
 
         if (vma) {
-                *mnt = mntget(vma->vm_file->f_path.mnt);
-                *dentry = dget(vma->vm_file->f_path.dentry);
+                *path = vma->vm_file->f_path;
+                path_get(&vma->vm_file->f_path);
                 result = 0;
         }
 
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index abfc6f5e56ca..8011528518bd 100644
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -103,7 +103,7 @@ int task_statm(struct mm_struct *mm, int *shared, int *text,
         return size;
 }
 
-int proc_exe_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
+int proc_exe_link(struct inode *inode, struct path *path)
 {
         struct vm_list_struct *vml;
         struct vm_area_struct *vma;
@@ -126,8 +126,8 @@ int proc_exe_link(struct inode *inode, struct dentry **dentry, struct vfsmount *
         }
 
         if (vma) {
-                *mnt = mntget(vma->vm_file->f_path.mnt);
-                *dentry = dget(vma->vm_file->f_path.dentry);
+                *path = vma->vm_file->f_path;
+                path_get(&vma->vm_file->f_path);
                 result = 0;
         }
 
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index d6a4f69bdc92..d9a9e718ad19 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -269,7 +269,7 @@ extern void kclist_add(struct kcore_list *, void *, size_t);
 #endif
 
 union proc_op {
-        int (*proc_get_link)(struct inode *, struct dentry **, struct vfsmount **);
+        int (*proc_get_link)(struct inode *, struct path *);
         int (*proc_read)(struct task_struct *task, char *page);
         int (*proc_show)(struct seq_file *m,
                 struct pid_namespace *ns, struct pid *pid,