[PATCH] r/o bind mount prepwork: inc_nlink() helper

[safe/jmp/linux-2.6] / fs / configfs / dir.c

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index df02545..8a3b6a1 100644 (file)
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -86,6 +86,32 @@ static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent * pare
        return sd;
 }
 
+/*
+ *
+ * Return -EEXIST if there is already a configfs element with the same
+ * name for the same parent.
+ *
+ * called with parent inode's i_mutex held
+ */
+int configfs_dirent_exists(struct configfs_dirent *parent_sd,
+                          const unsigned char *new)
+{
+       struct configfs_dirent * sd;
+
+       list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
+               if (sd->s_element) {
+                       const unsigned char *existing = configfs_get_name(sd);
+                       if (strcmp(existing, new))
+                               continue;
+                       else
+                               return -EEXIST;
+               }
+       }
+
+       return 0;
+}
+
+
 int configfs_make_dirent(struct configfs_dirent * parent_sd,
                         struct dentry * dentry, void * element,
                         umode_t mode, int type)
@@ -113,7 +139,7 @@ static int init_dir(struct inode * inode)
        inode->i_fop = &configfs_dir_operations;
 
        /* directory inodes start off with i_nlink == 2 (for "." entry) */
-       inode->i_nlink++;
+       inc_nlink(inode);
        return 0;
 }
 
@@ -136,12 +162,14 @@ static int create_dir(struct config_item * k, struct dentry * p,
        int error;
        umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
 
-       error = configfs_make_dirent(p->d_fsdata, d, k, mode,
-                                    CONFIGFS_DIR);
+       error = configfs_dirent_exists(p->d_fsdata, d->d_name.name);
+       if (!error)
+               error = configfs_make_dirent(p->d_fsdata, d, k, mode,
+                                            CONFIGFS_DIR);
        if (!error) {
                error = configfs_create(d, mode, init_dir);
                if (!error) {
-                       p->d_inode->i_nlink++;
+                       inc_nlink(p->d_inode);
                        (d)->d_op = &configfs_dentry_ops;
                } else {
                        struct configfs_dirent *sd = d->d_fsdata;