1 files changed, 182 insertions, 49 deletions

diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c
index 6577c588de9..5946ad98053 100644
--- a/fs/configfs/inode.c
+++ b/fs/configfs/inode.c
@@ -23,7 +23,8 @@
  *
  * configfs Copyright (C) 2005 Oracle.  All rights reserved.
  *
- * Please see Documentation/filesystems/configfs.txt for more information.
+ * Please see Documentation/filesystems/configfs/configfs.txt for more
+ * information.
  */
 
 #undef DEBUG
@@ -31,70 +32,189 @@
 #include <linux/pagemap.h>
 #include <linux/namei.h>
 #include <linux/backing-dev.h>
+#include <linux/capability.h>
+#include <linux/sched.h>
+#include <linux/lockdep.h>
+#include <linux/slab.h>
 
 #include <linux/configfs.h>
 #include "configfs_internal.h"
 
-extern struct super_block * configfs_sb;
+#ifdef CONFIG_LOCKDEP
+static struct lock_class_key default_group_class[MAX_LOCK_DEPTH];
+#endif
 
-static struct address_space_operations configfs_aops = {
+static const struct address_space_operations configfs_aops = {
 	.readpage	= simple_readpage,
-	.prepare_write	= simple_prepare_write,
-	.commit_write	= simple_commit_write
+	.write_begin	= simple_write_begin,
+	.write_end	= simple_write_end,
 };
 
 static struct backing_dev_info configfs_backing_dev_info = {
+	.name		= "configfs",
 	.ra_pages	= 0,	/* No readahead */
-	.capabilities	= BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
+	.capabilities	= BDI_CAP_NO_ACCT_AND_WRITEBACK,
 };
 
-struct inode * configfs_new_inode(mode_t mode)
+static const 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;
+	if (!sd_iattr) {
+		/* setting attributes for the first time, allocate now */
+		sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL);
+		if (!sd_iattr)
+			return -ENOMEM;
+		/* assign default attributes */
+		sd_iattr->ia_mode = sd->s_mode;
+		sd_iattr->ia_uid = GLOBAL_ROOT_UID;
+		sd_iattr->ia_gid = GLOBAL_ROOT_GID;
+		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 */
+
+	error = simple_setattr(dentry, iattr);
+	if (error)
+		return error;
+
+	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, umode_t mode)
+{
+	inode->i_mode = mode;
+	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(umode_t mode, struct configfs_dirent *sd,
+				 struct super_block *s)
 {
-	struct inode * inode = new_inode(configfs_sb);
+	struct inode * inode = new_inode(s);
 	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_ino = get_next_ino();
 		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;
 }
 
-int configfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *))
+#ifdef CONFIG_LOCKDEP
+
+static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
+					  struct inode *inode)
+{
+	int depth = sd->s_depth;
+
+	if (depth > 0) {
+		if (depth <= ARRAY_SIZE(default_group_class)) {
+			lockdep_set_class(&inode->i_mutex,
+					  &default_group_class[depth - 1]);
+		} else {
+			/*
+			 * In practice the maximum level of locking depth is
+			 * already reached. Just inform about possible reasons.
+			 */
+			pr_info("Too many levels of inodes for the locking correctness validator.\n");
+			pr_info("Spurious warnings may appear.\n");
+		}
+	}
+}
+
+#else /* CONFIG_LOCKDEP */
+
+static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
+					  struct inode *inode)
+{
+}
+
+#endif /* CONFIG_LOCKDEP */
+
+int configfs_create(struct dentry * dentry, umode_t mode, int (*init)(struct inode *))
 {
 	int error = 0;
-	struct inode * inode = NULL;
-	if (dentry) {
-		if (!dentry->d_inode) {
-			if ((inode = configfs_new_inode(mode))) {
-				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;
-				}
-				goto Proceed;
-			}
-			else
-				error = -ENOMEM;
-		} else
-			error = -EEXIST;
-	} else
-		error = -ENOENT;
-	goto Done;
+	struct inode *inode = NULL;
+	struct configfs_dirent *sd;
+	struct inode *p_inode;
 
- Proceed:
-	if (init)
+	if (!dentry)
+		return -ENOENT;
+
+	if (dentry->d_inode)
+		return -EEXIST;
+
+	sd = dentry->d_fsdata;
+	inode = configfs_new_inode(mode, sd, dentry->d_sb);
+	if (!inode)
+		return -ENOMEM;
+
+	p_inode = dentry->d_parent->d_inode;
+	p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME;
+	configfs_set_inode_lock_class(sd, inode);
+
+	if (init) {
 		error = init(inode);
-	if (!error) {
-		d_instantiate(dentry, inode);
-		if (S_ISDIR(mode) || S_ISLNK(mode))
-			dget(dentry);  /* pin link and directory dentries in core */
-	} else
-		iput(inode);
- Done:
+		if (error) {
+			iput(inode);
+			return error;
+		}
+	}
+	d_instantiate(dentry, inode);
+	if (S_ISDIR(mode) || S_ISLNK(mode))
+		dget(dentry);  /* pin link and directory dentries in core */
 	return error;
 }
 
@@ -103,10 +223,9 @@ 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();
+	BUG_ON(!sd || !sd->s_element);
 
 	/* These always have a dentry, so use that */
 	if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK))
@@ -114,7 +233,7 @@ 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;
 }
@@ -129,14 +248,14 @@ void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
 	struct dentry * dentry = sd->s_dentry;
 
 	if (dentry) {
-		spin_lock(&dcache_lock);
+		spin_lock(&dentry->d_lock);
 		if (!(d_unhashed(dentry) && dentry->d_inode)) {
-			dget_locked(dentry);
+			dget_dlock(dentry);
 			__d_drop(dentry);
-			spin_unlock(&dcache_lock);
+			spin_unlock(&dentry->d_lock);
 			simple_unlink(parent->d_inode, dentry);
 		} else
-			spin_unlock(&dcache_lock);
+			spin_unlock(&dentry->d_lock);
 	}
 }
 
@@ -145,12 +264,18 @@ 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)
 			continue;
 		if (!strcmp(configfs_get_name(sd), name)) {
+			spin_lock(&configfs_dirent_lock);
 			list_del_init(&sd->s_sibling);
+			spin_unlock(&configfs_dirent_lock);
 			configfs_drop_dentry(sd, dir);
 			configfs_put(sd);
 			break;
@@ -159,4 +284,12 @@ void configfs_hash_and_remove(struct dentry * dir, const char * name)
 	mutex_unlock(&dir->d_inode->i_mutex);
 }
 
+int __init configfs_inode_init(void)
+{
+	return bdi_init(&configfs_backing_dev_info);
+}
 
+void configfs_inode_exit(void)
+{
+	bdi_destroy(&configfs_backing_dev_info);
+}