sysfs: implement new features

index a74ca4a..d50d3ac 100644
@@ -245,6 +245,10 @@ static void sysfs_deactivate(struct sysfs_dirent *sd)
 	 */
 	v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active);
 
+	/* file is dying, notify pollers */
+	if (sysfs_type(sd) == SYSFS_FILE)
+		sysfs_notify_file(sd);
+
 	if (v != SD_DEACTIVATED_BIAS)
 		wait_for_completion(&wait);
 

index d50d3ac..b042a2e 100644
@@ -295,6 +295,9 @@ void release_sysfs_dirent(struct sysfs_dirent * sd)
 		sysfs_put(sd->s_link.target);
 	if (sd->s_flags & SYSFS_FLAG_NAME_COPIED)
 		kfree(sd->s_name);
+	if (sd->s_flags & SYSFS_FLAG_LINK_NAME_FMT_COPIED)
+		kfree(sd->s_link.name_fmt);
+
 	kfree(sd->s_iattr);
 	sysfs_free_ino(sd->s_ino);
 	kmem_cache_free(sysfs_dir_cachep, sd);

index 16e10de..7ea9186 100644
@@ -425,7 +425,7 @@ int sysfs_create_link(struct kobject *kobj, struct kobject *target,
 	if (!target_sd)
 		return -ENOENT;
 
-	sd = sysfs_add_link(parent_sd, name, SYSFS_COPY_NAME, target_sd);
+	sd = __sysfs_add_link(parent_sd, name, SYSFS_COPY_NAME, target_sd, 0);
 
 	sysfs_put(target_sd);
 

283 lines not on this page · raw message

index 732b292..9167032 100644
@@ -9,6 +9,7 @@ struct sysfs_elem_dir {
 
 struct sysfs_elem_link {
 	struct sysfs_dirent	*target;
+	const char		*name_fmt;
 };
 
 struct sysfs_elem_file {

@@ -62,6 +63,7 @@ struct sysfs_dirent {
 #define SYSFS_FLAG_MASK			~SYSFS_TYPE_MASK
 #define SYSFS_FLAG_REMOVED		0x0200
 #define SYSFS_FLAG_NAME_COPIED		0x0400
+#define SYSFS_FLAG_LINK_NAME_FMT_COPIED	0x0800
 
 static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
 {

@@ -152,4 +154,11 @@ extern const struct file_operations sysfs_bin_file_operations;
 /*
  * symlink.c
  */
+struct sysfs_dirent *__sysfs_add_link(struct sysfs_dirent *parent,
+				      const char *name, mode_t mode,
+				      struct sysfs_dirent *target, int format);
+int sysfs_link_name(const char *fmt, struct sysfs_dirent *target,
+		    const char **link_name, struct sysfs_dirent *renamed_sd,
+		    struct sysfs_dirent *new_parent, const char *new_name);
+
 extern const struct inode_operations sysfs_link_inode_operations;

index f0279a7..5afe3bd 100644
@@ -29,7 +29,7 @@ struct vm_area_struct;
  * specific flags.
  */
 #define SYSFS_DIR_MODE		(S_IRWXU | S_IRUGO | S_IXUGO)
-#define SYSFS_COPY_NAME		010000	/* copy passed @name */
+#define SYSFS_COPY_NAME		010000	/* copy passed @name[_fmt] */
 
 /* collection of all flags for verification */
 #define SYSFS_MODE_FLAGS	SYSFS_COPY_NAME

@@ -61,7 +61,7 @@ struct sysfs_dirent *sysfs_add_bin(struct sysfs_dirent *parent,
 			const char *name, mode_t mode, size_t size,
 			const struct sysfs_bin_ops *bops, void *data);
 struct sysfs_dirent *sysfs_add_link(struct sysfs_dirent *parent,
-			const char *name, mode_t mode,
+			const char *name_fmt, mode_t mode,
 			struct sysfs_dirent *target);
 
 struct sysfs_dirent *sysfs_find_child(struct sysfs_dirent *parent,

@@ -100,7 +100,7 @@ static inline struct sysfs_dirent *sysfs_add_bin(struct sysfs_dirent *parent,
 }
 
 static inline struct sysfs_dirent *sysfs_add_link(struct sysfs_dirent *parent,
-			const char *name, mode_t mode,
+			const char *name_fmt, mode_t mode,
 			struct sysfs_dirent *target)
 {
 	return NULL;

index b042a2e..bb9e87e 100644
@@ -495,7 +495,8 @@ static struct inode *sysfs_addrm_get_parent_inode(struct sysfs_addrm_cxt *acxt,
  *
  *	Get @parent and set sd->s_parent to it and increment nlink of
  *	parent inode if @sd is a directory and link into the children
- *	list of the parent.
+ *	list of the parent.  If LINK_CHAINED flag is set, @sd is also
+ *	chained into the parent's s_dir.links list.
  *
  *	This function should be called between calls to
  *	sysfs_addrm_start() and sysfs_addrm_finish() and should be

@@ -522,6 +523,11 @@ int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *parent,
 
 	sysfs_link_sibling(sd);
 
+	if (sd->s_flags & SYSFS_FLAG_LINK_CHAINED) {
+		sd->s_link.next = sd->s_link.target->s_dir.links;
+		sd->s_link.target->s_dir.links = sd;
+	}
+
 	if (parent_inode) {
 		parent_inode->i_ctime = parent_inode->i_mtime = CURRENT_TIME;
 		if (sysfs_type(sd) == SYSFS_DIR)

@@ -537,7 +543,8 @@ int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *parent,
  *	@sd: sysfs_dirent to be added
  *
  *	Mark @sd removed and drop nlink of parent inode if @sd is a
- *	directory.  @sd is unlinked from the children list.
+ *	directory.  @sd is unlinked from the children list and the
+ *	s_dir.links list if applicable.
  *
  *	This function should be called between calls to
  *	sysfs_addrm_start() and sysfs_addrm_finish() and should be

@@ -554,6 +561,21 @@ void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
 
 	parent_inode = sysfs_addrm_get_parent_inode(acxt, sd->s_parent);
 
+	if (sd->s_flags & SYSFS_FLAG_LINK_CHAINED) {
+		struct sysfs_dirent *target = sd->s_link.target;
+		struct sysfs_dirent **p;
+		int removed = 0;
+
+		for (p = &target->s_dir.links; *p; p = &(*p)->s_link.next) {
+			if (*p == sd) {
+				*p = sd->s_link.next;
+				removed = 1;
+				break;
+			}
+		}
+		BUG_ON(!removed);
+	}
+
 	sysfs_unlink_sibling(sd);
 
 	sd->s_flags |= SYSFS_FLAG_REMOVED;

index 296fef5..53cc8a6 100644
@@ -231,6 +231,9 @@ struct sysfs_dirent *__sysfs_add_link(struct sysfs_dirent *parent,
 		goto err;
 
 	if (format) {
+		/* chain into the target's links list */
+		flags |= SYSFS_FLAG_LINK_CHAINED;
+
 		/* SYSFS_COPY_NAME means 'copy the format string' */
 		rc = -ENOMEM;
 		if (mode & SYSFS_COPY_NAME) {

index 9167032..f704279 100644
@@ -5,10 +5,13 @@ struct sysfs_elem_dir {
 	void			*data;
 	/* children list starts here and goes through sd->s_sibling */
 	struct sysfs_dirent	*children;
+	/* symlinks list starts here and goes through sd->s_link.next */
+	struct sysfs_dirent	*links;
 };
 
 struct sysfs_elem_link {
 	struct sysfs_dirent	*target;
+	struct sysfs_dirent	*next;
 	const char		*name_fmt;
 };
 

@@ -64,6 +67,7 @@ struct sysfs_dirent {
 #define SYSFS_FLAG_REMOVED		0x0200
 #define SYSFS_FLAG_NAME_COPIED		0x0400
 #define SYSFS_FLAG_LINK_NAME_FMT_COPIED	0x0800
+#define SYSFS_FLAG_LINK_CHAINED		0x1000
 
 static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
 {

index bb9e87e..4a04cb4 100644
@@ -956,6 +956,12 @@ void __sysfs_remove(struct sysfs_dirent *sd, int recurse)
 		    (sysfs_type(cur) == SYSFS_DIR || cur->s_parent != sd))
 			continue;
 
+		/* kill all symlinks pointing to @cur */
+		if (sysfs_type(cur) == SYSFS_DIR)
+			while (cur->s_dir.links)
+				sysfs_remove_one(&acxt, cur->s_dir.links);
+
+		/* kill @cur */
 		sysfs_remove_one(&acxt, cur);
 	} while ((cur = next));
 

index 4a04cb4..eac8fef 100644
@@ -1196,6 +1196,7 @@ static int sysfs_prep_rename(struct sysfs_rename_context *rcxt,
 {
 	struct sysfs_rcxt_rename_ent *rent;
 	struct sysfs_rcxt_mutex_ent *ment;
+	struct sysfs_dirent *cur;
 	int rc;
 
 	INIT_LIST_HEAD(&rcxt->mutexes);

@@ -1220,6 +1221,50 @@ static int sysfs_prep_rename(struct sysfs_rename_context *rcxt,
 		goto err;
 
 	/*
+	 * prep links pointing to @sd and its children
+	 */
+	cur = NULL;
+	while ((cur = sysfs_tree_walk_next(sd, cur))) {
+		struct sysfs_dirent *link;
+
+		if (sysfs_type(cur) != SYSFS_DIR)
+			continue;
+
+		for (link = cur->s_dir.links; link; link = link->s_link.next) {
+			const char *link_new_name;
+			int copied;
+
+			rc = sysfs_link_name(link->s_link.name_fmt,
+					     link->s_link.target,
+					     &link_new_name,
+					     sd, new_parent, new_name);
+			if (rc < 0)
+				goto err;
+			copied = rc;
+
+			if (!strcmp(link->s_name, link_new_name)) {
+				if (copied)
+					kfree(link_new_name);
+				continue;
+			}
+
+			rc = -ENOMEM;
+			rent = sysfs_rcxt_add(rcxt, link, link->s_parent);
+			if (!rent) {
+				mutex_unlock(&sysfs_mutex);
+				goto err;
+			}
+
+			rent->new_name = link_new_name;
+			rent->new_name_copied = copied;
+
+			rc = sysfs_rcxt_get_dentries(rcxt, rent);
+			if (rc)
+				goto err;
+		}
+	}
+
+	/*
 	 * lock all i_mutexes
 	 */
  try_lock:

index eac8fef..88ec749 100644
@@ -118,8 +118,15 @@ struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd)
 		/* look it up */
 		parent = dentry;
 		mutex_lock(&parent->d_inode->i_mutex);
+
 		dentry = lookup_one_len_kern(cur->s_name, parent,
 					     strlen(cur->s_name));
+		/* negative dentry means @sd is plugged, return -ENOENT */
+		if (!dentry->d_inode) {
+			dput(dentry);
+			dentry = ERR_PTR(-ENOENT);
+		}
+
 		mutex_unlock(&parent->d_inode->i_mutex);
 		dput(parent);
 

@@ -322,12 +329,13 @@ static struct dentry_operations sysfs_dentry_ops = {
 /**
  *	sysfs_new_dirent - allocate and initialize sysfs_dirent
  *	@name: name for the new sysfs_dirent
- *	@mode: mask of bits from S_IRWXUGO | SYSFS_COPY_NAME
+ *	@mode: mask of bits from S_IRWXUGO | SYSFS_COPY_NAME | SYSFS_PLUGGED
  *	@type: one of SYSFS_{DIR|FILE|BIN|LINK}
  *
  *	Allocate and initialize a sysfs_dirent with the specified
  *	parameters.  If SYSFS_COPY_NAME is specified in @mode, @name
- *	is duplicated.
+ *	is duplicated.  If SYSFS_PLUGGED is set, the node is
+ *	initialized into plugged state.
  *
  *	LOCKING:
  *	Kernel thread context (may sleep).

@@ -351,6 +359,10 @@ struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
 		flags |= SYSFS_FLAG_NAME_COPIED;
 	}
 
+	/* start plugged? */
+	if (mode & SYSFS_PLUGGED)
+		flags |= SYSFS_FLAG_PLUGGED;
+
 	/* normalize mode */
 	mode &= S_IALLUGO;
 

@@ -512,12 +524,14 @@ static struct inode *sysfs_addrm_get_parent_inode(struct sysfs_addrm_cxt *acxt,
 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *parent,
 		  struct sysfs_dirent *sd)
 {
-	struct inode *parent_inode;
+	struct inode *parent_inode = NULL;
 
 	if (sysfs_find_dirent(parent, sd->s_name))
 		return -EEXIST;
 
-	parent_inode = sysfs_addrm_get_parent_inode(acxt, parent);
+	/* if plugged, don't update parent inode, will be updated on unplug */
+	if (!(sd->s_flags & SYSFS_FLAG_PLUGGED))
+		parent_inode = sysfs_addrm_get_parent_inode(acxt, parent);
 
 	sd->s_parent = sysfs_get(parent);
 

@@ -555,11 +569,13 @@ int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *parent,
  */
 void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
 {
-	struct inode *parent_inode;
+	struct inode *parent_inode = NULL;
 
 	BUG_ON(sd->s_flags & SYSFS_FLAG_REMOVED);
 
-	parent_inode = sysfs_addrm_get_parent_inode(acxt, sd->s_parent);
+	/* if plugged, don't update parent inode, will be updated on unplug */
+	if (!(sd->s_flags & SYSFS_FLAG_PLUGGED))
+		parent_inode = sysfs_addrm_get_parent_inode(acxt, sd->s_parent);
 
 	if (sd->s_flags & SYSFS_FLAG_LINK_CHAINED) {
 		struct sysfs_dirent *target = sd->s_link.target;

@@ -805,7 +821,9 @@ EXPORT_SYMBOL_GPL(sysfs_find_child);
  *
  *	Add a new directory under @parent with the specified
  *	parameters.  If SYSFS_COPY_NAME is set in @mode, @name is
- *	copied before being used.
+ *	copied before being used.  If SYSFS_PLUGGED is set in @mode,
+ *	the new directory will start plugged (won't be visible till
+ *	unplugged).
  *
  *	LOCKING:
  *	Kernel thread context (may sleep).

@@ -830,6 +848,84 @@ struct sysfs_dirent *sysfs_add_dir(struct sysfs_dirent *parent,
 }
 EXPORT_SYMBOL_GPL(sysfs_add_dir);
 
+/**
+ *	sysfs_unplug - unplug a plugged sysfs_dirent
+ *	@sd: sysfs_dirent to unplug
+ *
+ *	A plugged sysfs_dirent isn't visible to userland.  As are all
+ *	its children and symlinks point to the sysfs_dirent or its
+ *	children.  This function unplugs @sd and makes it visible to
+ *	userland.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep).  Uses sysfs_mutex.
+ */
+void sysfs_unplug(struct sysfs_dirent *sd)
+{
+	struct sysfs_addrm_cxt acxt;
+
+	/* Unplugging performs parent inode update delayed from
+	 * add/removal.  Also, sysfs_op_mutex grabbed by addrm_start
+	 * guarantees renaming to see consistent plugged status.
+	 */
+	sysfs_addrm_start(&acxt);
+
+	if (sd->s_flags & SYSFS_FLAG_PLUGGED) {
+		struct inode *parent_inode =
+			sysfs_addrm_get_parent_inode(&acxt, sd->s_parent);
+
+		sd->s_flags &= ~SYSFS_FLAG_PLUGGED;
+
+		if (parent_inode) {
+			parent_inode->i_ctime =
+			parent_inode->i_mtime = CURRENT_TIME;
+
+			if (sysfs_type(sd) == SYSFS_DIR)
+				inc_nlink(parent_inode);
+		}
+	}
+
+	sysfs_addrm_finish(&acxt);
+}
+EXPORT_SYMBOL_GPL(sysfs_unplug);
+
+static int sysfs_plugged(struct sysfs_dirent *sd,
+			 struct sysfs_dirent *new_parent)
+{
+	struct sysfs_dirent *cur;
+
+	/* @sd itself is plugged? */
+	if (sd->s_flags & SYSFS_FLAG_PLUGGED)
+		return 1;
+
+	/* Parent override for renaming.  This is used to determine
+	 * whether @sd will be plugged when moved under @new_parent.
+	 */
+	if (!new_parent)
+		new_parent = sd->s_parent;
+
+	/* is one of @sd's acnestors plugged? */
+	for (cur = new_parent; cur; cur = cur->s_parent)
+		if (cur->s_flags & SYSFS_FLAG_PLUGGED)
+			return 1;
+
+	/* A symlink is plugged if its target is plugged.  Check
+	 * whether the target is plugged unless the symlink is known
+	 * to be unplugged.
+	 */
+	if (sysfs_type(sd) != SYSFS_LINK ||
+	    (sd->s_flags & SYSFS_FLAG_LINK_UNPLUGGED))
+		return 0;
+
+	for (cur = sd->s_link.target; cur; cur = cur->s_parent)
+		if (cur->s_flags & SYSFS_FLAG_PLUGGED)
+			return 1;
+
+	/* if unplugged, mark it to accelerate future plugged test */
+	sd->s_flags |= SYSFS_FLAG_LINK_UNPLUGGED;
+	return 0;
+}
+
 static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
 				struct nameidata *nd)
 {

@@ -842,8 +938,8 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
 
 	sd = sysfs_find_dirent(parent_sd, dentry->d_name.name);
 
-	/* no such entry */
-	if (!sd)
+	/* no such entry or plugged */
+	if (unlikely(!sd || sysfs_plugged(sd, NULL)))
 		goto out_unlock;
 
 	/* attach dentry and inode */

@@ -1021,6 +1117,10 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
 			const char * name;
 			int len;
 
+			/* skip plugged nodes */
+			if (unlikely(sysfs_plugged(pos, NULL)))
+				continue;
+
 			name = pos->s_name;
 			len = strlen(name);
 			filp->f_pos = ino = pos->s_ino;

@@ -1398,33 +1498,44 @@ EXPORT_SYMBOL_GPL(sysfs_rename);
  */
 int sysfs_chmod(struct sysfs_dirent *sd, mode_t mode)
 {
-	struct dentry *dentry;
-	struct inode *inode;
-	struct iattr newattrs;
-	int rc;
+	mode_t new_mode = (mode & S_IALLUGO) | (sd->s_mode & ~S_IALLUGO);
+	struct dentry *dentry = NULL;
+	struct inode *inode = NULL;
+	int rc = 0;
 
 	mutex_lock(&sysfs_op_mutex);
-	dentry = sysfs_get_dentry(sd);
-	mutex_unlock(&sysfs_op_mutex);
-	if (IS_ERR(dentry))
-		return PTR_ERR(dentry);
 
-	inode = dentry->d_inode;
+	/* If @sd is plugged, dentry and inode aren't there and can't
+	 * be looked up.  Just update @sd->s_mode.
+	 */
+	if (!sysfs_plugged(sd, NULL)) {
+		struct iattr newattrs;
 
-	mutex_lock(&inode->i_mutex);
+		dentry = sysfs_get_dentry(sd);
+		if (IS_ERR(dentry)) {
+			rc = PTR_ERR(dentry);
+			goto out_unlock_op;
+		}
+		inode = dentry->d_inode;
 
-	newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
-	newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
-	rc = notify_change(dentry, &newattrs);
+		mutex_lock(&inode->i_mutex);
 
-	if (rc == 0) {
-		mutex_lock(&sysfs_mutex);
-		sd->s_mode = newattrs.ia_mode;
-		mutex_unlock(&sysfs_mutex);
+		newattrs.ia_mode = new_mode;
+		newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
+		rc = notify_change(dentry, &newattrs);
+		if (rc)
+			goto out_unlock_inode;
 	}
 
-	mutex_unlock(&inode->i_mutex);
+	mutex_lock(&sysfs_mutex);
+	sd->s_mode = new_mode;
+	mutex_unlock(&sysfs_mutex);
 
+ out_unlock_inode:
+	if (inode)
+		mutex_unlock(&inode->i_mutex);
+ out_unlock_op:
+	mutex_unlock(&sysfs_op_mutex);
 	dput(dentry);
 	return rc;
 }

index 0aeea4b..bd61cca 100644
@@ -128,7 +128,8 @@ static int sysfs_count_nlink(struct sysfs_dirent *sd)
 	int nr = 0;
 
 	for (child = sd->s_dir.children; child; child = child->s_sibling)
-		if (sysfs_type(child) == SYSFS_DIR)
+		if (sysfs_type(child) == SYSFS_DIR &&
+		    !(child->s_flags & SYSFS_FLAG_PLUGGED))
 			nr++;
 
 	return nr + 2;

index f704279..51f346d 100644
@@ -64,10 +64,12 @@ struct sysfs_dirent {
 #define SYSFS_LINK			0x0008
 
 #define SYSFS_FLAG_MASK			~SYSFS_TYPE_MASK
+#define SYSFS_FLAG_PLUGGED		0x0100
 #define SYSFS_FLAG_REMOVED		0x0200
 #define SYSFS_FLAG_NAME_COPIED		0x0400
 #define SYSFS_FLAG_LINK_NAME_FMT_COPIED	0x0800
 #define SYSFS_FLAG_LINK_CHAINED		0x1000
+#define SYSFS_FLAG_LINK_UNPLUGGED	0x2000
 
 static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
 {

index 5afe3bd..5a8c9f1 100644
@@ -30,9 +30,10 @@ struct vm_area_struct;
  */
 #define SYSFS_DIR_MODE		(S_IRWXU | S_IRUGO | S_IXUGO)
 #define SYSFS_COPY_NAME		010000	/* copy passed @name[_fmt] */
+#define SYSFS_PLUGGED		020000	/* plug the node on creation */
 
 /* collection of all flags for verification */
-#define SYSFS_MODE_FLAGS	SYSFS_COPY_NAME
+#define SYSFS_MODE_FLAGS	(SYSFS_COPY_NAME | SYSFS_PLUGGED)
 
 struct sysfs_file_ops {
 	ssize_t (*show)(char *page, void *data, void *parent_data);

@@ -63,6 +64,7 @@ struct sysfs_dirent *sysfs_add_bin(struct sysfs_dirent *parent,
 struct sysfs_dirent *sysfs_add_link(struct sysfs_dirent *parent,
 			const char *name_fmt, mode_t mode,
 			struct sysfs_dirent *target);
+void sysfs_unplug(struct sysfs_dirent *sd);
 
 struct sysfs_dirent *sysfs_find_child(struct sysfs_dirent *parent,
 				      const char *name);

@@ -106,6 +108,10 @@ static inline struct sysfs_dirent *sysfs_add_link(struct sysfs_dirent *parent,
 	return NULL;
 }
 
+static inline void sysfs_unplug(struct sysfs_dirent *sd)
+{
+}
+
 static inline struct sysfs_dirent *sysfs_find_child(struct sysfs_dirent *parent,
 						    const char *name)
 {

index d6cc7b3..1f705d2 100644
@@ -231,10 +231,16 @@ struct sysfs_dirent *sysfs_add_bin(struct sysfs_dirent *parent,
 {
 	struct sysfs_dirent *sd;
 
+	/* for batch error handling */
+	if (IS_ERR(parent))
+		return ERR_PTR(-EBADF);
+
 	/* allocate and initialize */
 	sd = sysfs_new_dirent(name, mode, SYSFS_BIN);
-	if (!sd)
+	if (!sd) {
+		sysfs_set_batch_error(parent, -ENOMEM);
 		return ERR_PTR(-ENOMEM);
+	}
 
 	sd->s_bin.ops = bops;
 	sd->s_bin.size = size;

233 lines not on this page · raw message

index 1d93940..3412732 100644
@@ -498,6 +498,10 @@ void sysfs_notify_file(struct sysfs_dirent *sd)
 {
 	struct sysfs_open_dirent *od;
 
+	/* for batch error handling */
+	if (IS_ERR(sd))
+		return;
+
 	BUG_ON(sysfs_type(sd) != SYSFS_FILE);
 
 	spin_lock(&sysfs_open_dirent_lock);

@@ -545,10 +549,16 @@ struct sysfs_dirent *sysfs_add_file(struct sysfs_dirent *parent,
 {
 	struct sysfs_dirent *sd;
 
+	/* for batch error handling */
+	if (IS_ERR(parent))
+		return ERR_PTR(-EBADF);
+
 	/* allocate and initialize */
 	sd = sysfs_new_dirent(name, mode, SYSFS_FILE);
-	if (!sd)
+	if (!sd) {
+		sysfs_set_batch_error(parent, -ENOMEM);
 		return ERR_PTR(-ENOMEM);
+	}
 
 	sd->s_file.ops = fops;
 	sd->s_file.data = data;

index 53cc8a6..7e0fd89 100644
@@ -217,6 +217,10 @@ struct sysfs_dirent *__sysfs_add_link(struct sysfs_dirent *parent,
 	struct sysfs_addrm_cxt acxt;
 	int rc;
 
+	/* for batch error handling */
+	if (IS_ERR(parent) || IS_ERR(target))
+		return ERR_PTR(-EBADF);
+
 	/* acquire locks early for link name formatting */
 	sysfs_addrm_start(&acxt);
 

@@ -280,6 +284,9 @@ struct sysfs_dirent *__sysfs_add_link(struct sysfs_dirent *parent,
 		kfree(name_fmt);
 	if (flags & SYSFS_FLAG_NAME_COPIED)
 		kfree(name);
+
+	sysfs_set_batch_error(parent, rc);
+	sysfs_set_batch_error(target, rc);
 	return ERR_PTR(rc);
 }
 

index 51f346d..ec0b308 100644
@@ -52,7 +52,15 @@ struct sysfs_dirent {
 	unsigned int		s_flags;
 	ino_t			s_ino;
 	umode_t			s_mode;
-	struct iattr		*s_iattr;
+
+	/* Make s_iattr and s_batch_error share the room.  This is
+	 * okay because s_iattr is used only after a node is unplugged
+	 * while s_batch_error is used only while a node is plugged.
+	 */
+	union {
+		struct iattr		*s_iattr;
+		int			s_batch_error;
+	};
 };
 
 #define SD_DEACTIVATED_BIAS		INT_MIN

@@ -120,6 +128,8 @@ struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
 				      const unsigned char *name);
 struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
 
+void sysfs_set_batch_error(struct sysfs_dirent *sd, int error);
+
 void __sysfs_remove(struct sysfs_dirent *sd, int recurse);
 
 void release_sysfs_dirent(struct sysfs_dirent *sd);

index 5a8c9f1..a8dfc6b 100644
@@ -64,6 +64,7 @@ struct sysfs_dirent *sysfs_add_bin(struct sysfs_dirent *parent,
 struct sysfs_dirent *sysfs_add_link(struct sysfs_dirent *parent,
 			const char *name_fmt, mode_t mode,
 			struct sysfs_dirent *target);
+int sysfs_check_batch_error(struct sysfs_dirent *sd);
 void sysfs_unplug(struct sysfs_dirent *sd);
 
 struct sysfs_dirent *sysfs_find_child(struct sysfs_dirent *parent,

@@ -108,6 +109,11 @@ static inline struct sysfs_dirent *sysfs_add_link(struct sysfs_dirent *parent,
 	return NULL;
 }
 
+static inline int sysfs_check_batch_error(struct sysfs_dirent *sd)
+{
+	return 0;
+}
+
 static inline void sysfs_unplug(struct sysfs_dirent *sd)
 {
 }

index 1f705d2..ae6986d 100644
@@ -1,9 +1,15 @@
 /*
- * bin.c - binary file operations for sysfs.
+ * fs/sysfs/bin.c - sysfs binary file implementation
  *
  * Copyright (c) 2003 Patrick Mochel
  * Copyright (c) 2003 Matthew Wilcox
  * Copyright (c) 2004 Silicon Graphics, Inc.
+ * Copyright (c) 2007 SUSE Linux Products GmbH
+ * Copyright (c) 2007 Tejun Heo <[email protected]>
+ *
+ * This file is released under the GPLv2.
+ *
+ * Please see Documentation/filesystems/sysfs.txt for more information.
  */
 
 #undef DEBUG

index f18da1b..a8571f4 100644
@@ -1,5 +1,13 @@
 /*
- * dir.c - Operations for sysfs directories.
+ * fs/sysfs/dir.c - sysfs core and dir operation implementation
+ *
+ * Copyright (c) 2001-3 Patrick Mochel
+ * Copyright (c) 2007 SUSE Linux Products GmbH
+ * Copyright (c) 2007 Tejun Heo <[email protected]>
+ *
+ * This file is released under the GPLv2.
+ *
+ * Please see Documentation/filesystems/sysfs.txt for more information.
  */
 
 #undef DEBUG

index 3412732..68ec732 100644
@@ -1,5 +1,13 @@
 /*
- * file.c - operations for regular (text) files.
+ * fs/sysfs/file.c - sysfs regular (text) file implementation
+ *
+ * Copyright (c) 2001-3 Patrick Mochel
+ * Copyright (c) 2007 SUSE Linux Products GmbH
+ * Copyright (c) 2007 Tejun Heo <[email protected]>
+ *
+ * This file is released under the GPLv2.
+ *
+ * Please see Documentation/filesystems/sysfs.txt for more information.
  */
 
 #include <linux/module.h>

index bd61cca..6834a11 100644
@@ -1,7 +1,11 @@
 /*
- * inode.c - basic inode and dentry operations.
+ * fs/sysfs/inode.c - basic sysfs inode and dentry operations
  *
- * sysfs is Copyright (c) 2001-3 Patrick Mochel
+ * Copyright (c) 2001-3 Patrick Mochel
+ * Copyright (c) 2007 SUSE Linux Products GmbH
+ * Copyright (c) 2007 Tejun Heo <[email protected]>
+ *
+ * This file is released under the GPLv2.
  *
  * Please see Documentation/filesystems/sysfs.txt for more information.
  */

index 7ea9186..c0bc77d 100644
@@ -3,6 +3,8 @@
  *
  * Copyright (c) 2001,2002 Patrick Mochel
  * Copyright (c) 2004 Silicon Graphics, Inc.
+ * Copyright (c) 2007 SUSE Linux Products GmbH
+ * Copyright (c) 2007 Tejun Heo <[email protected]>
  *
  * This is compatibility interface which wraps the primary interface
  * defined in linux/sysfs.h to remain compatible with the original

index d61eb08..642988f 100644
@@ -1,5 +1,13 @@
 /*
- * mount.c - operations for initializing and mounting sysfs.
+ * fs/sysfs/symlink.c - operations for initializing and mounting sysfs
+ *
+ * Copyright (c) 2001-3 Patrick Mochel
+ * Copyright (c) 2007 SUSE Linux Products GmbH
+ * Copyright (c) 2007 Tejun Heo <[email protected]>
+ *
+ * This file is released under the GPLv2.
+ *
+ * Please see Documentation/filesystems/sysfs.txt for more information.
  */
 
 #define DEBUG 

index 7e0fd89..ed2550c 100644
@@ -1,5 +1,13 @@
 /*
- * symlink.c - operations for sysfs symlinks.
+ * fs/sysfs/symlink.c - sysfs symlink implementation
+ *
+ * Copyright (c) 2001-3 Patrick Mochel
+ * Copyright (c) 2007 SUSE Linux Products GmbH
+ * Copyright (c) 2007 Tejun Heo <[email protected]>
+ *
+ * This file is released under the GPLv2.
+ *
+ * Please see Documentation/filesystems/sysfs.txt for more information.
  */
 
 #include <linux/fs.h>

index ec0b308..a92a95d 100644
@@ -1,3 +1,13 @@
+/*
+ * fs/sysfs/sysfs.h - sysfs internal header file
+ *
+ * Copyright (c) 2001-3 Patrick Mochel
+ * Copyright (c) 2007 SUSE Linux Products GmbH
+ * Copyright (c) 2007 Tejun Heo <[email protected]>
+ *
+ * This file is released under the GPLv2.
+ */
+
 struct sysfs_open_dirent;
 
 /* type-specific structures for sysfs_dirent->s_* union members */

index 4c821c2..dbbad99 100644
@@ -3,6 +3,8 @@
  *
  * Copyright (c) 2001,2002 Patrick Mochel
  * Copyright (c) 2004 Silicon Graphics, Inc.
+ * Copyright (c) 2007 SUSE Linux Products GmbH
+ * Copyright (c) 2007 Tejun Heo <[email protected]>
  *
  * This is compatibility interface which wraps the primary interface
  * defined in linux/sysfs.h to remain compatible with the original

index a8dfc6b..22cdbf4 100644
@@ -1,6 +1,10 @@
 /*
  * sysfs.h - definitions for the device driver filesystem
  *
+ * Copyright (c) 2001-3 Patrick Mochel
+ * Copyright (c) 2007 SUSE Linux Products GmbH
+ * Copyright (c) 2007 Tejun Heo <[email protected]>
+ *
  * Primary sysfs interface based on sysfs_dirent
  *
  * If you're using sysfs directly instead of via driver model, please