configfs: Add permission and ownership to configfs objects.
configfs always made item and attribute ownership root.root and
permissions based on a umask of 022. Add ->setattr() to allow
chown(2)/chmod(2), and persist the changes for the lifetime of the
items and attributes.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c
index 6577c58..737842f 100644
--- a/fs/configfs/inode.c
+++ b/fs/configfs/inode.c
@@ -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 @@
.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 @@
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 @@
*/
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 @@
if (sd->s_type & CONFIGFS_ITEM_ATTR) {
attr = sd->s_element;
- return attr->name;
+ return attr->ca_name;
}
return NULL;
}
@@ -130,13 +221,17 @@
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 @@
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)