Merge branch 'linux-2.6'

4 files changed, 79 insertions, 115 deletions

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index f281cc6584b0..4948d9bc405d 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -440,7 +440,7 @@ int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
 /**
  *	sysfs_remove_one - remove sysfs_dirent from parent
  *	@acxt: addrm context to use
- *	@sd: sysfs_dirent to be added
+ *	@sd: sysfs_dirent to be removed
  *
  *	Mark @sd removed and drop nlink of parent inode if @sd is a
  *	directory.  @sd is unlinked from the children list.
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 4045bdcc4b33..a271c87c4472 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -20,43 +20,6 @@
 
 #include "sysfs.h"
 
-#define to_sattr(a) container_of(a,struct subsys_attribute, attr)
-
-/*
- * Subsystem file operations.
- * These operations allow subsystems to have files that can be 
- * read/written. 
- */
-static ssize_t 
-subsys_attr_show(struct kobject * kobj, struct attribute * attr, char * page)
-{
-	struct kset *kset = to_kset(kobj);
-	struct subsys_attribute * sattr = to_sattr(attr);
-	ssize_t ret = -EIO;
-
-	if (sattr->show)
-		ret = sattr->show(kset, page);
-	return ret;
-}
-
-static ssize_t 
-subsys_attr_store(struct kobject * kobj, struct attribute * attr, 
-		  const char * page, size_t count)
-{
-	struct kset *kset = to_kset(kobj);
-	struct subsys_attribute * sattr = to_sattr(attr);
-	ssize_t ret = -EIO;
-
-	if (sattr->store)
-		ret = sattr->store(kset, page, count);
-	return ret;
-}
-
-static struct sysfs_ops subsys_sysfs_ops = {
-	.show	= subsys_attr_show,
-	.store	= subsys_attr_store,
-};
-
 /*
  * There's one sysfs_buffer for each open file and one
  * sysfs_open_dirent for each sysfs_dirent with one or more open
@@ -66,7 +29,7 @@ static struct sysfs_ops subsys_sysfs_ops = {
  * sysfs_dirent->s_attr.open points to sysfs_open_dirent.  s_attr.open
  * is protected by sysfs_open_dirent_lock.
  */
-static spinlock_t sysfs_open_dirent_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(sysfs_open_dirent_lock);
 
 struct sysfs_open_dirent {
 	atomic_t		refcnt;
@@ -354,31 +317,23 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
 {
 	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
 	struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
-	struct sysfs_buffer * buffer;
-	struct sysfs_ops * ops = NULL;
-	int error;
+	struct sysfs_buffer *buffer;
+	struct sysfs_ops *ops;
+	int error = -EACCES;
 
 	/* need attr_sd for attr and ops, its parent for kobj */
 	if (!sysfs_get_active_two(attr_sd))
 		return -ENODEV;
 
-	/* if the kobject has no ktype, then we assume that it is a subsystem
-	 * itself, and use ops for it.
-	 */
-	if (kobj->kset && kobj->kset->ktype)
-		ops = kobj->kset->ktype->sysfs_ops;
-	else if (kobj->ktype)
+	/* every kobject with an attribute needs a ktype assigned */
+	if (kobj->ktype && kobj->ktype->sysfs_ops)
 		ops = kobj->ktype->sysfs_ops;
-	else
-		ops = &subsys_sysfs_ops;
-
-	error = -EACCES;
-
-	/* No sysfs operations, either from having no subsystem,
-	 * or the subsystem have no operations.
-	 */
-	if (!ops)
+	else {
+		printk(KERN_ERR "missing sysfs attribute operations for "
+		       "kobject: %s\n", kobject_name(kobj));
+		WARN_ON(1);
 		goto err_out;
+	}
 
 	/* File needs write support.
 	 * The inode's perms must say it's ok, 
@@ -568,7 +523,11 @@ int sysfs_add_file_to_group(struct kobject *kobj,
 	struct sysfs_dirent *dir_sd;
 	int error;
 
-	dir_sd = sysfs_get_dirent(kobj->sd, group);
+	if (group)
+		dir_sd = sysfs_get_dirent(kobj->sd, group);
+	else
+		dir_sd = sysfs_get(kobj->sd);
+
 	if (!dir_sd)
 		return -ENOENT;
 
@@ -656,7 +615,10 @@ void sysfs_remove_file_from_group(struct kobject *kobj,
 {
 	struct sysfs_dirent *dir_sd;
 
-	dir_sd = sysfs_get_dirent(kobj->sd, group);
+	if (group)
+		dir_sd = sysfs_get_dirent(kobj->sd, group);
+	else
+		dir_sd = sysfs_get(kobj->sd);
 	if (dir_sd) {
 		sysfs_hash_and_remove(dir_sd, attr->name);
 		sysfs_put(dir_sd);
diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c
index d1972374655a..0871c3dadce1 100644
--- a/fs/sysfs/group.c
+++ b/fs/sysfs/group.c
@@ -16,25 +16,31 @@
 #include "sysfs.h"
 
 
-static void remove_files(struct sysfs_dirent *dir_sd,
+static void remove_files(struct sysfs_dirent *dir_sd, struct kobject *kobj,
 			 const struct attribute_group *grp)
 {
 	struct attribute *const* attr;
+	int i;
 
-	for (attr = grp->attrs; *attr; attr++)
-		sysfs_hash_and_remove(dir_sd, (*attr)->name);
+	for (i = 0, attr = grp->attrs; *attr; i++, attr++)
+		if (!grp->is_visible ||
+		    grp->is_visible(kobj, *attr, i))
+			sysfs_hash_and_remove(dir_sd, (*attr)->name);
 }
 
-static int create_files(struct sysfs_dirent *dir_sd,
+static int create_files(struct sysfs_dirent *dir_sd, struct kobject *kobj,
 			const struct attribute_group *grp)
 {
 	struct attribute *const* attr;
-	int error = 0;
+	int error = 0, i;
 
-	for (attr = grp->attrs; *attr && !error; attr++)
-		error = sysfs_add_file(dir_sd, *attr, SYSFS_KOBJ_ATTR);
+	for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++)
+		if (!grp->is_visible ||
+		    grp->is_visible(kobj, *attr, i))
+			error |=
+				sysfs_add_file(dir_sd, *attr, SYSFS_KOBJ_ATTR);
 	if (error)
-		remove_files(dir_sd, grp);
+		remove_files(dir_sd, kobj, grp);
 	return error;
 }
 
@@ -54,7 +60,7 @@ int sysfs_create_group(struct kobject * kobj,
 	} else
 		sd = kobj->sd;
 	sysfs_get(sd);
-	error = create_files(sd, grp);
+	error = create_files(sd, kobj, grp);
 	if (error) {
 		if (grp->name)
 			sysfs_remove_subdir(sd);
@@ -75,7 +81,7 @@ void sysfs_remove_group(struct kobject * kobj,
 	} else
 		sd = sysfs_get(dir_sd);
 
-	remove_files(sd, grp);
+	remove_files(sd, kobj, grp);
 	if (grp->name)
 		sysfs_remove_subdir(sd);
 
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index 3eac20c63c41..5f66c4466151 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -19,39 +19,6 @@
 
 #include "sysfs.h"
 
-static int object_depth(struct sysfs_dirent *sd)
-{
-	int depth = 0;
-
-	for (; sd->s_parent; sd = sd->s_parent)
-		depth++;
-
-	return depth;
-}
-
-static int object_path_length(struct sysfs_dirent * sd)
-{
-	int length = 1;
-
-	for (; sd->s_parent; sd = sd->s_parent)
-		length += strlen(sd->s_name) + 1;
-
-	return length;
-}
-
-static void fill_object_path(struct sysfs_dirent *sd, char *buffer, int length)
-{
-	--length;
-	for (; sd->s_parent; sd = sd->s_parent) {
-		int cur = strlen(sd->s_name);
-
-		/* back up enough to print this bus id with '/' */
-		length -= cur;
-		strncpy(buffer + length, sd->s_name, cur);
-		*(buffer + --length) = '/';
-	}
-}
-
 /**
  *	sysfs_create_link - create symlink between two objects.
  *	@kobj:	object whose directory we're creating the link in.
@@ -112,7 +79,6 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char
 	return error;
 }
 
-
 /**
  *	sysfs_remove_link - remove symlink in object's directory.
  *	@kobj:	object we're acting for.
@@ -124,24 +90,54 @@ void sysfs_remove_link(struct kobject * kobj, const char * name)
 	sysfs_hash_and_remove(kobj->sd, name);
 }
 
-static int sysfs_get_target_path(struct sysfs_dirent * parent_sd,
-				 struct sysfs_dirent * target_sd, char *path)
+static int sysfs_get_target_path(struct sysfs_dirent *parent_sd,
+				 struct sysfs_dirent *target_sd, char *path)
 {
-	char * s;
-	int depth, size;
+	struct sysfs_dirent *base, *sd;
+	char *s = path;
+	int len = 0;
+
+	/* go up to the root, stop at the base */
+	base = parent_sd;
+	while (base->s_parent) {
+		sd = target_sd->s_parent;
+		while (sd->s_parent && base != sd)
+			sd = sd->s_parent;
+
+		if (base == sd)
+			break;
+
+		strcpy(s, "../");
+		s += 3;
+		base = base->s_parent;
+	}
+
+	/* determine end of target string for reverse fillup */
+	sd = target_sd;
+	while (sd->s_parent && sd != base) {
+		len += strlen(sd->s_name) + 1;
+		sd = sd->s_parent;
+	}
 
-	depth = object_depth(parent_sd);
-	size = object_path_length(target_sd) + depth * 3 - 1;
-	if (size > PATH_MAX)
+	/* check limits */
+	if (len < 2)
+		return -EINVAL;
+	len--;
+	if ((s - path) + len > PATH_MAX)
 		return -ENAMETOOLONG;
 
-	pr_debug("%s: depth = %d, size = %d\n", __FUNCTION__, depth, size);
+	/* reverse fillup of target string from target to base */
+	sd = target_sd;
+	while (sd->s_parent && sd != base) {
+		int slen = strlen(sd->s_name);
 
-	for (s = path; depth--; s += 3)
-		strcpy(s,"../");
+		len -= slen;
+		strncpy(s + len, sd->s_name, slen);
+		if (len)
+			s[--len] = '/';
 
-	fill_object_path(target_sd, path, size);
-	pr_debug("%s: path = '%s'\n", __FUNCTION__, path);
+		sd = sd->s_parent;
+	}
 
 	return 0;
 }