configfs: Add permission and ownership to configfs objects.
[linux-2.6.git] / fs / configfs / inode.c
index 6577c58..737842f 100644 (file)
@@ -31,6 +31,7 @@
 #include <linux/pagemap.h>
 #include <linux/namei.h>
 #include <linux/backing-dev.h>
+#include <linux/capability.h>
 
 #include <linux/configfs.h>
 #include "configfs_internal.h"
@@ -48,18 +49,107 @@ static struct backing_dev_info configfs_backing_dev_info = {
        .capabilities   = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
 };
 
-struct inode * configfs_new_inode(mode_t mode)
+static struct inode_operations configfs_inode_operations ={
+       .setattr        = configfs_setattr,
+};
+
+int configfs_setattr(struct dentry * dentry, struct iattr * iattr)
+{
+       struct inode * inode = dentry->d_inode;
+       struct configfs_dirent * sd = dentry->d_fsdata;
+       struct iattr * sd_iattr;
+       unsigned int ia_valid = iattr->ia_valid;
+       int error;
+
+       if (!sd)
+               return -EINVAL;
+
+       sd_iattr = sd->s_iattr;
+
+       error = inode_change_ok(inode, iattr);
+       if (error)
+               return error;
+
+       error = inode_setattr(inode, iattr);
+       if (error)
+               return error;
+
+       if (!sd_iattr) {
+               /* setting attributes for the first time, allocate now */
+               sd_iattr = kmalloc(sizeof(struct iattr), GFP_KERNEL);
+               if (!sd_iattr)
+                       return -ENOMEM;
+               /* assign default attributes */
+               memset(sd_iattr, 0, sizeof(struct iattr));
+               sd_iattr->ia_mode = sd->s_mode;
+               sd_iattr->ia_uid = 0;
+               sd_iattr->ia_gid = 0;
+               sd_iattr->ia_atime = sd_iattr->ia_mtime = sd_iattr->ia_ctime = CURRENT_TIME;
+               sd->s_iattr = sd_iattr;
+       }
+
+       /* attributes were changed atleast once in past */
+
+       if (ia_valid & ATTR_UID)
+               sd_iattr->ia_uid = iattr->ia_uid;
+       if (ia_valid & ATTR_GID)
+               sd_iattr->ia_gid = iattr->ia_gid;
+       if (ia_valid & ATTR_ATIME)
+               sd_iattr->ia_atime = timespec_trunc(iattr->ia_atime,
+                                               inode->i_sb->s_time_gran);
+       if (ia_valid & ATTR_MTIME)
+               sd_iattr->ia_mtime = timespec_trunc(iattr->ia_mtime,
+                                               inode->i_sb->s_time_gran);
+       if (ia_valid & ATTR_CTIME)
+               sd_iattr->ia_ctime = timespec_trunc(iattr->ia_ctime,
+                                               inode->i_sb->s_time_gran);
+       if (ia_valid & ATTR_MODE) {
+               umode_t mode = iattr->ia_mode;
+
+               if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
+                       mode &= ~S_ISGID;
+               sd_iattr->ia_mode = sd->s_mode = mode;
+       }
+
+       return error;
+}
+
+static inline void set_default_inode_attr(struct inode * inode, mode_t mode)
+{
+       inode->i_mode = mode;
+       inode->i_uid = 0;
+       inode->i_gid = 0;
+       inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+}
+
+static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
+{
+       inode->i_mode = iattr->ia_mode;
+       inode->i_uid = iattr->ia_uid;
+       inode->i_gid = iattr->ia_gid;
+       inode->i_atime = iattr->ia_atime;
+       inode->i_mtime = iattr->ia_mtime;
+       inode->i_ctime = iattr->ia_ctime;
+}
+
+struct inode * configfs_new_inode(mode_t mode, struct configfs_dirent * sd)
 {
        struct inode * inode = new_inode(configfs_sb);
        if (inode) {
-               inode->i_mode = mode;
-               inode->i_uid = 0;
-               inode->i_gid = 0;
                inode->i_blksize = PAGE_CACHE_SIZE;
                inode->i_blocks = 0;
-               inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
                inode->i_mapping->a_ops = &configfs_aops;
                inode->i_mapping->backing_dev_info = &configfs_backing_dev_info;
+               inode->i_op = &configfs_inode_operations;
+
+               if (sd->s_iattr) {
+                       /* sysfs_dirent has non-default attributes
+                        * get them for the new inode from persistent copy
+                        * in sysfs_dirent
+                        */
+                       set_inode_attr(inode, sd->s_iattr);
+               } else
+                       set_default_inode_attr(inode, mode);
        }
        return inode;
 }
@@ -70,7 +160,8 @@ int configfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *
        struct inode * inode = NULL;
        if (dentry) {
                if (!dentry->d_inode) {
-                       if ((inode = configfs_new_inode(mode))) {
+                       struct configfs_dirent *sd = dentry->d_fsdata;
+                       if ((inode = configfs_new_inode(mode, sd))) {
                                if (dentry->d_parent && dentry->d_parent->d_inode) {
                                        struct inode *p_inode = dentry->d_parent->d_inode;
                                        p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME;
@@ -103,7 +194,7 @@ int configfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *
  */
 const unsigned char * configfs_get_name(struct configfs_dirent *sd)
 {
-       struct attribute * attr;
+       struct configfs_attribute *attr;
 
        if (!sd || !sd->s_element)
                BUG();
@@ -114,7 +205,7 @@ const unsigned char * configfs_get_name(struct configfs_dirent *sd)
 
        if (sd->s_type & CONFIGFS_ITEM_ATTR) {
                attr = sd->s_element;
-               return attr->name;
+               return attr->ca_name;
        }
        return NULL;
 }
@@ -130,13 +221,17 @@ void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
 
        if (dentry) {
                spin_lock(&dcache_lock);
+               spin_lock(&dentry->d_lock);
                if (!(d_unhashed(dentry) && dentry->d_inode)) {
                        dget_locked(dentry);
                        __d_drop(dentry);
+                       spin_unlock(&dentry->d_lock);
                        spin_unlock(&dcache_lock);
                        simple_unlink(parent->d_inode, dentry);
-               } else
+               } else {
+                       spin_unlock(&dentry->d_lock);
                        spin_unlock(&dcache_lock);
+               }
        }
 }
 
@@ -145,6 +240,10 @@ void configfs_hash_and_remove(struct dentry * dir, const char * name)
        struct configfs_dirent * sd;
        struct configfs_dirent * parent_sd = dir->d_fsdata;
 
+       if (dir->d_inode == NULL)
+               /* no inode means this hasn't been made visible yet */
+               return;
+
        mutex_lock(&dir->d_inode->i_mutex);
        list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
                if (!sd->s_element)