1 files changed, 96 insertions, 6 deletions

diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
index aff7b2dfa8ee..565cac1d4200 100644
--- a/fs/sysfs/inode.c
+++ b/fs/sysfs/inode.c
@@ -26,18 +26,107 @@ static struct backing_dev_info sysfs_backing_dev_info = {
         .capabilities   = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
 };
 
-struct inode * sysfs_new_inode(mode_t mode)
+static struct inode_operations sysfs_inode_operations ={
+        .setattr        = sysfs_setattr,
+};
+
+int sysfs_setattr(struct dentry * dentry, struct iattr * iattr)
+{
+        struct inode * inode = dentry->d_inode;
+        struct sysfs_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 = 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 * sysfs_new_inode(mode_t mode, struct sysfs_dirent * sd)
 {
         struct inode * inode = new_inode(sysfs_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 = &sysfs_aops;
                 inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
+                inode->i_op = &sysfs_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;
 }
@@ -48,7 +137,8 @@ int sysfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *))
         struct inode * inode = NULL;
         if (dentry) {
                 if (!dentry->d_inode) {
-                        if ((inode = sysfs_new_inode(mode))) {
+                        struct sysfs_dirent * sd = dentry->d_fsdata;
+                        if ((inode = sysfs_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;