7 files changed, 127 insertions, 27 deletions

diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c
index d4aaa88d0214..78899eeab974 100644
--- a/fs/sysfs/bin.c
+++ b/fs/sysfs/bin.c
@@ -25,7 +25,7 @@ fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count)
         struct kobject * kobj = to_kobj(dentry->d_parent);
 
         if (!attr->read)
-                return -EINVAL;
+                return -EIO;
 
         return attr->read(kobj, buffer, off, count);
 }
@@ -71,7 +71,7 @@ flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count)
         struct kobject *kobj = to_kobj(dentry->d_parent);
 
         if (!attr->write)
-                return -EINVAL;
+                return -EIO;
 
         return attr->write(kobj, buffer, offset, count);
 }
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index fe198210bc2d..37d7a6875d86 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -101,18 +101,19 @@ static int create_dir(struct kobject * k, struct dentry * p,
         down(&p->d_inode->i_sem);
         *d = sysfs_get_dentry(p,n);
         if (!IS_ERR(*d)) {
-                error = sysfs_create(*d, mode, init_dir);
+                error = sysfs_make_dirent(p->d_fsdata, *d, k, mode, SYSFS_DIR);
                 if (!error) {
-                        error = sysfs_make_dirent(p->d_fsdata, *d, k, mode,
-                                                SYSFS_DIR);
+                        error = sysfs_create(*d, mode, init_dir);
                         if (!error) {
                                 p->d_inode->i_nlink++;
                                 (*d)->d_op = &sysfs_dentry_ops;
                                 d_rehash(*d);
                         }
                 }
-                if (error && (error != -EEXIST))
+                if (error && (error != -EEXIST)) {
+                        sysfs_put((*d)->d_fsdata);
                         d_drop(*d);
+                }
                 dput(*d);
         } else
                 error = PTR_ERR(*d);
@@ -171,17 +172,19 @@ static int sysfs_attach_attr(struct sysfs_dirent * sd, struct dentry * dentry)
                 init = init_file;
         }
 
+        dentry->d_fsdata = sysfs_get(sd);
+        sd->s_dentry = dentry;
         error = sysfs_create(dentry, (attr->mode & S_IALLUGO) | S_IFREG, init);
-        if (error)
+        if (error) {
+                sysfs_put(sd);
                 return error;
+        }
 
         if (bin_attr) {
                 dentry->d_inode->i_size = bin_attr->size;
                 dentry->d_inode->i_fop = &bin_fops;
         }
         dentry->d_op = &sysfs_dentry_ops;
-        dentry->d_fsdata = sysfs_get(sd);
-        sd->s_dentry = dentry;
         d_rehash(dentry);
 
         return 0;
@@ -191,13 +194,15 @@ static int sysfs_attach_link(struct sysfs_dirent * sd, struct dentry * dentry)
 {
         int err = 0;
 
+        dentry->d_fsdata = sysfs_get(sd);
+        sd->s_dentry = dentry;
         err = sysfs_create(dentry, S_IFLNK|S_IRWXUGO, init_symlink);
         if (!err) {
                 dentry->d_op = &sysfs_dentry_ops;
-                dentry->d_fsdata = sysfs_get(sd);
-                sd->s_dentry = dentry;
                 d_rehash(dentry);
-        }
+        } else
+                sysfs_put(sd);
+
         return err;
 }
 
@@ -228,6 +233,7 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
 
 struct inode_operations sysfs_dir_inode_operations = {
         .lookup         = sysfs_lookup,
+        .setattr        = sysfs_setattr,
 };
 
 static void remove_dir(struct dentry * d)
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 364208071e17..849aac115460 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -23,7 +23,7 @@ subsys_attr_show(struct kobject * kobj, struct attribute * attr, char * page)
 {
         struct subsystem * s = to_subsys(kobj);
         struct subsys_attribute * sattr = to_sattr(attr);
-        ssize_t ret = 0;
+        ssize_t ret = -EIO;
 
         if (sattr->show)
                 ret = sattr->show(s,page);
@@ -36,7 +36,7 @@ subsys_attr_store(struct kobject * kobj, struct attribute * attr,
 {
         struct subsystem * s = to_subsys(kobj);
         struct subsys_attribute * sattr = to_sattr(attr);
-        ssize_t ret = 0;
+        ssize_t ret = -EIO;
 
         if (sattr->store)
                 ret = sattr->store(s,page,count);
@@ -182,7 +182,7 @@ fill_write_buffer(struct sysfs_buffer * buffer, const char __user * buf, size_t
                 return -ENOMEM;
 
         if (count >= PAGE_SIZE)
-                count = PAGE_SIZE - 1;
+                count = PAGE_SIZE;
         error = copy_from_user(buffer->page,buf,count);
         buffer->needs_read_fill = 1;
         return error ? -EFAULT : count;
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;
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index 5c805bb1a4b7..f1117e885bd6 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -28,6 +28,7 @@ static struct sysfs_dirent sysfs_root = {
         .s_children     = LIST_HEAD_INIT(sysfs_root.s_children),
         .s_element      = NULL,
         .s_type         = SYSFS_ROOT,
+        .s_iattr        = NULL,
 };
 
 static int sysfs_fill_super(struct super_block *sb, void *data, int silent)
@@ -42,7 +43,8 @@ static int sysfs_fill_super(struct super_block *sb, void *data, int silent)
         sb->s_time_gran = 1;
         sysfs_sb = sb;
 
-        inode = sysfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO);
+        inode = sysfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
+                                 &sysfs_root);
         if (inode) {
                 inode->i_op = &sysfs_dir_inode_operations;
                 inode->i_fop = &sysfs_dir_operations;
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index dfdf70174354..fae57c83a722 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -43,7 +43,7 @@ static void fill_object_path(struct kobject * kobj, char * buffer, int length)
         }
 }
 
-static int sysfs_add_link(struct dentry * parent, char * name, struct kobject * target)
+static int sysfs_add_link(struct dentry * parent, const char * name, struct kobject * target)
 {
         struct sysfs_dirent * parent_sd = parent->d_fsdata;
         struct sysfs_symlink * sl;
@@ -79,7 +79,7 @@ exit1:
  *      @target:        object we're pointing to.
  *      @name:          name of the symlink.
  */
-int sysfs_create_link(struct kobject * kobj, struct kobject * target, char * name)
+int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char * name)
 {
         struct dentry * dentry = kobj->dentry;
         int error = 0;
@@ -99,13 +99,13 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, char * nam
  *      @name:  name of the symlink to remove.
  */
 
-void sysfs_remove_link(struct kobject * kobj, char * name)
+void sysfs_remove_link(struct kobject * kobj, const char * name)
 {
         sysfs_hash_and_remove(kobj->dentry,name);
 }
 
 static int sysfs_get_target_path(struct kobject * kobj, struct kobject * target,
-                                   char *path)
+                                 char *path)
 {
         char * s;
         int depth, size;
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index a8a24a0c0b3b..29da6f5f07c8 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -2,7 +2,7 @@
 extern struct vfsmount * sysfs_mount;
 extern kmem_cache_t *sysfs_dir_cachep;
 
-extern struct inode * sysfs_new_inode(mode_t mode);
+extern struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent *);
 extern int sysfs_create(struct dentry *, int mode, int (*init)(struct inode *));
 
 extern int sysfs_make_dirent(struct sysfs_dirent *, struct dentry *, void *,
@@ -17,6 +17,7 @@ extern void sysfs_remove_subdir(struct dentry *);
 
 extern const unsigned char * sysfs_get_name(struct sysfs_dirent *sd);
 extern void sysfs_drop_dentry(struct sysfs_dirent *sd, struct dentry *parent);
+extern int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
 
 extern struct rw_semaphore sysfs_rename_sem;
 extern struct super_block * sysfs_sb;
@@ -75,6 +76,7 @@ static inline void release_sysfs_dirent(struct sysfs_dirent * sd)
                 kobject_put(sl->target_kobj);
                 kfree(sl);
         }
+        kfree(sd->s_iattr);
         kmem_cache_free(sysfs_dir_cachep, sd);
 }