X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=fs%2Fsysfs%2Finode.c;h=1be853706e9991b0b4f270479acde63f5cff527a;hb=608e266a2d4e62c1b98c1c573064b6afe8c06a58;hp=617d10cea07d3af1f26aec8fae65906fca924bc3;hpb=3e5190380ebef77f2b015c9e7a4ca225a3d75021;p=powerpc.git

diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
index 617d10cea0..1be853706e 100644
--- a/fs/sysfs/inode.c
+++ b/fs/sysfs/inode.c
@@ -133,89 +133,94 @@ static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
  */
 static struct lock_class_key sysfs_inode_imutex_key;
 
-struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent * sd)
+void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode)
 {
-	struct inode * inode = new_inode(sysfs_sb);
-	if (inode) {
-		inode->i_blocks = 0;
-		inode->i_mapping->a_ops = &sysfs_aops;
-		inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
-		inode->i_op = &sysfs_inode_operations;
-		inode->i_ino = sd->s_ino;
-		lockdep_set_class(&inode->i_mutex, &sysfs_inode_imutex_key);
-
-		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;
+	inode->i_blocks = 0;
+	inode->i_mapping->a_ops = &sysfs_aops;
+	inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
+	inode->i_op = &sysfs_inode_operations;
+	inode->i_ino = sd->s_ino;
+	lockdep_set_class(&inode->i_mutex, &sysfs_inode_imutex_key);
+
+	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, sd->s_mode);
 }
 
-int sysfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *))
+/**
+ *	sysfs_get_inode - get inode for sysfs_dirent
+ *	@sd: sysfs_dirent to allocate inode for
+ *
+ *	Get inode for @sd.  If such inode doesn't exist, a new inode
+ *	is allocated and basics are initialized.  New inode is
+ *	returned locked.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).
+ *
+ *	RETURNS:
+ *	Pointer to allocated inode on success, NULL on failure.
+ */
+struct inode * sysfs_get_inode(struct sysfs_dirent *sd)
 {
-	int error = 0;
-	struct inode * inode = NULL;
-	if (dentry) {
-		if (!dentry->d_inode) {
-			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;
-				}
-				goto Proceed;
-			}
-			else 
-				error = -ENOMEM;
-		} else
-			error = -EEXIST;
-	} else 
-		error = -ENOENT;
-	goto Done;
-
- Proceed:
-	if (init)
-		error = init(inode);
-	if (!error) {
-		d_instantiate(dentry, inode);
-		if (S_ISDIR(mode))
-			dget(dentry);  /* pin only directory dentry in core */
-	} else
-		iput(inode);
- Done:
-	return error;
+	struct inode *inode;
+
+	inode = iget_locked(sysfs_sb, sd->s_ino);
+	if (inode && (inode->i_state & I_NEW))
+		sysfs_init_inode(sd, inode);
+
+	return inode;
 }
 
-static inline void orphan_all_buffers(struct inode *node)
+/**
+ *	sysfs_instantiate - instantiate dentry
+ *	@dentry: dentry to be instantiated
+ *	@inode: inode associated with @sd
+ *
+ *	Unlock @inode if locked and instantiate @dentry with @inode.
+ *
+ *	LOCKING:
+ *	None.
+ */
+void sysfs_instantiate(struct dentry *dentry, struct inode *inode)
 {
-	struct sysfs_buffer_collection *set;
-	struct sysfs_buffer *buf;
-
-	mutex_lock_nested(&node->i_mutex, I_MUTEX_CHILD);
-	set = node->i_private;
-	if (set) {
-		list_for_each_entry(buf, &set->associates, associates) {
-			down(&buf->sem);
-			buf->orphaned = 1;
-			up(&buf->sem);
+	BUG_ON(!dentry || dentry->d_inode);
+
+	if (inode->i_state & I_NEW) {
+		unlock_new_inode(inode);
+
+		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;
 		}
 	}
-	mutex_unlock(&node->i_mutex);
-}
 
+	d_instantiate(dentry, inode);
+}
 
-/*
- * Unhashes the dentry corresponding to given sysfs_dirent
- * Called with parent inode's i_mutex held.
+/**
+ *	sysfs_drop_dentry - drop dentry for the specified sysfs_dirent
+ *	@sd: target sysfs_dirent
+ *
+ *	Drop dentry for @sd.  @sd must have been unlinked from its
+ *	parent on entry to this function such that it can't be looked
+ *	up anymore.
+ *
+ *	@sd->s_dentry which is protected with sysfs_lock points to the
+ *	currently associated dentry but we're not holding a reference
+ *	to it and racing with dput().  Grab dcache_lock and verify
+ *	dentry before dropping it.  If @sd->s_dentry is NULL or dput()
+ *	beats us, no need to bother.
  */
-void sysfs_drop_dentry(struct sysfs_dirent * sd, struct dentry * parent)
+void sysfs_drop_dentry(struct sysfs_dirent *sd)
 {
 	struct dentry *dentry = NULL;
+	struct timespec curtime;
 	struct inode *inode;
 
 	/* We're not holding a reference to ->s_dentry dentry but the
@@ -224,65 +229,89 @@ void sysfs_drop_dentry(struct sysfs_dirent * sd, struct dentry * parent)
 	spin_lock(&sysfs_lock);
 	spin_lock(&dcache_lock);
 
-	/* dget dentry if it's still alive */
-	if (sd->s_dentry && sd->s_dentry->d_inode)
+	/* drop dentry if it's there and dput() didn't kill it yet */
+	if (sd->s_dentry && sd->s_dentry->d_inode) {
 		dentry = dget_locked(sd->s_dentry);
+		spin_lock(&dentry->d_lock);
+		__d_drop(dentry);
+		spin_unlock(&dentry->d_lock);
+	}
 
 	spin_unlock(&dcache_lock);
 	spin_unlock(&sysfs_lock);
 
-	/* drop dentry */
-	if (dentry) {
-		spin_lock(&dcache_lock);
-		spin_lock(&dentry->d_lock);
-		if (!d_unhashed(dentry) && dentry->d_inode) {
-			inode = dentry->d_inode;
-			spin_lock(&inode->i_lock);
-			__iget(inode);
-			spin_unlock(&inode->i_lock);
-			dget_locked(dentry);
-			__d_drop(dentry);
-			spin_unlock(&dentry->d_lock);
-			spin_unlock(&dcache_lock);
-			simple_unlink(parent->d_inode, dentry);
-			orphan_all_buffers(inode);
-			iput(inode);
-		} else {
-			spin_unlock(&dentry->d_lock);
-			spin_unlock(&dcache_lock);
-		}
-
+	dput(dentry);
+	/* XXX: unpin if directory, this will go away soon */
+	if (sysfs_type(sd) == SYSFS_DIR)
 		dput(dentry);
+
+	/* adjust nlink and update timestamp */
+	curtime = CURRENT_TIME;
+
+	inode = ilookup(sysfs_sb, sd->s_ino);
+	if (inode) {
+		mutex_lock(&inode->i_mutex);
+
+		inode->i_ctime = curtime;
+		drop_nlink(inode);
+		if (sysfs_type(sd) == SYSFS_DIR)
+			drop_nlink(inode);
+
+		mutex_unlock(&inode->i_mutex);
+		iput(inode);
+	}
+
+	/* adjust nlink and udpate timestamp of the parent */
+	inode = ilookup(sysfs_sb, sd->s_parent->s_ino);
+	if (inode) {
+		mutex_lock(&inode->i_mutex);
+
+		inode->i_ctime = inode->i_mtime = curtime;
+		if (sysfs_type(sd) == SYSFS_DIR)
+			drop_nlink(inode);
+
+		mutex_unlock(&inode->i_mutex);
+		iput(inode);
 	}
 }
 
-int sysfs_hash_and_remove(struct dentry * dir, const char * name)
+int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name)
 {
-	struct sysfs_dirent * sd;
-	struct sysfs_dirent * parent_sd;
+	struct dentry *dir;
+	struct sysfs_dirent **pos, *sd;
 	int found = 0;
 
-	if (!dir)
+	if (!dir_sd)
 		return -ENOENT;
 
+	dir = dir_sd->s_dentry;
+
 	if (dir->d_inode == NULL)
 		/* no inode means this hasn't been made visible yet */
 		return -ENOENT;
 
-	parent_sd = dir->d_fsdata;
 	mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
-	list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
-		if (!sd->s_type)
+	for (pos = &dir_sd->s_children; *pos; pos = &(*pos)->s_sibling) {
+		sd = *pos;
+
+		if (!sysfs_type(sd))
 			continue;
 		if (!strcmp(sd->s_name, name)) {
-			list_del_init(&sd->s_sibling);
-			sysfs_drop_dentry(sd, dir);
-			sysfs_put(sd);
+			sd->s_flags |= SYSFS_FLAG_REMOVED;
+			*pos = sd->s_sibling;
+			sd->s_sibling = NULL;
 			found = 1;
 			break;
 		}
 	}
 	mutex_unlock(&dir->d_inode->i_mutex);
 
-	return found ? 0 : -ENOENT;
+	if (!found)
+		return -ENOENT;
+
+	sysfs_drop_dentry(sd);
+	sysfs_deactivate(sd);
+	sysfs_put(sd);
+
+	return 0;
 }