diff options
| -rw-r--r-- | fs/sysfs/dir.c | 2 | ||||
| -rw-r--r-- | fs/sysfs/symlink.c | 88 | ||||
| -rw-r--r-- | fs/sysfs/sysfs.h | 9 |
3 files changed, 53 insertions, 46 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index e9fddcc59447..2a94dc36d166 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -54,7 +54,7 @@ void release_sysfs_dirent(struct sysfs_dirent * sd) parent_sd = sd->s_parent; if (sd->s_type & SYSFS_KOBJ_LINK) - kobject_put(sd->s_elem.symlink.target_kobj); + sysfs_put(sd->s_elem.symlink.target_sd); if (sd->s_type & SYSFS_COPY_NAME) kfree(sd->s_name); kfree(sd->s_iattr); diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index 27df635b786a..ff605d3f4d33 100644 --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -11,50 +11,49 @@ #include "sysfs.h" -static int object_depth(struct kobject * kobj) +static int object_depth(struct sysfs_dirent *sd) { - struct kobject * p = kobj; int depth = 0; - do { depth++; } while ((p = p->parent)); + + for (; sd->s_parent; sd = sd->s_parent) + depth++; + return depth; } -static int object_path_length(struct kobject * kobj) +static int object_path_length(struct sysfs_dirent * sd) { - struct kobject * p = kobj; int length = 1; - do { - length += strlen(kobject_name(p)) + 1; - p = p->parent; - } while (p); + + for (; sd->s_parent; sd = sd->s_parent) + length += strlen(sd->s_name) + 1; + return length; } -static void fill_object_path(struct kobject * kobj, char * buffer, int length) +static void fill_object_path(struct sysfs_dirent *sd, char *buffer, int length) { - struct kobject * p; - --length; - for (p = kobj; p; p = p->parent) { - int cur = strlen(kobject_name(p)); + 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,kobject_name(p),cur); + strncpy(buffer + length, sd->s_name, cur); *(buffer + --length) = '/'; } } -static int sysfs_add_link(struct dentry * parent, const char * name, struct kobject * target) +static int sysfs_add_link(struct sysfs_dirent * parent_sd, const char * name, + struct sysfs_dirent * target_sd) { - struct sysfs_dirent * parent_sd = parent->d_fsdata; struct sysfs_dirent * sd; sd = sysfs_new_dirent(name, S_IFLNK|S_IRWXUGO, SYSFS_KOBJ_LINK); if (!sd) return -ENOMEM; - sd->s_elem.symlink.target_kobj = kobject_get(target); + sd->s_elem.symlink.target_sd = target_sd; sysfs_attach_dirent(sd, parent_sd, NULL); return 0; } @@ -68,6 +67,8 @@ static int sysfs_add_link(struct dentry * parent, const char * name, struct kobj int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char * name) { struct dentry *dentry = NULL; + struct sysfs_dirent *parent_sd = NULL; + struct sysfs_dirent *target_sd = NULL; int error = -EEXIST; BUG_ON(!name); @@ -80,11 +81,27 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char if (!dentry) return -EFAULT; + parent_sd = dentry->d_fsdata; + + /* target->dentry can go away beneath us but is protected with + * kobj_sysfs_assoc_lock. Fetch target_sd from it. + */ + spin_lock(&kobj_sysfs_assoc_lock); + if (target->dentry) + target_sd = sysfs_get(target->dentry->d_fsdata); + spin_unlock(&kobj_sysfs_assoc_lock); + + if (!target_sd) + return -ENOENT; mutex_lock(&dentry->d_inode->i_mutex); if (!sysfs_dirent_exist(dentry->d_fsdata, name)) - error = sysfs_add_link(dentry, name, target); + error = sysfs_add_link(parent_sd, name, target_sd); mutex_unlock(&dentry->d_inode->i_mutex); + + if (error) + sysfs_put(target_sd); + return error; } @@ -100,14 +117,14 @@ 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) +static int sysfs_get_target_path(struct sysfs_dirent * parent_sd, + struct sysfs_dirent * target_sd, char *path) { char * s; int depth, size; - depth = object_depth(kobj); - size = object_path_length(target) + depth * 3 - 1; + depth = object_depth(parent_sd); + size = object_path_length(target_sd) + depth * 3 - 1; if (size > PATH_MAX) return -ENAMETOOLONG; @@ -116,7 +133,7 @@ static int sysfs_get_target_path(struct kobject * kobj, struct kobject * target, for (s = path; depth--; s += 3) strcpy(s,"../"); - fill_object_path(target, path, size); + fill_object_path(target_sd, path, size); pr_debug("%s: path = '%s'\n", __FUNCTION__, path); return 0; @@ -124,27 +141,16 @@ static int sysfs_get_target_path(struct kobject * kobj, struct kobject * target, static int sysfs_getlink(struct dentry *dentry, char * path) { - struct kobject *kobj, *target_kobj; - int error = 0; - - kobj = sysfs_get_kobject(dentry->d_parent); - if (!kobj) - return -EINVAL; - - target_kobj = sysfs_get_kobject(dentry); - if (!target_kobj) { - kobject_put(kobj); - return -EINVAL; - } + struct sysfs_dirent *sd = dentry->d_fsdata; + struct sysfs_dirent *parent_sd = sd->s_parent; + struct sysfs_dirent *target_sd = sd->s_elem.symlink.target_sd; + int error; down_read(&sysfs_rename_sem); - error = sysfs_get_target_path(kobj, target_kobj, path); + error = sysfs_get_target_path(parent_sd, target_sd, path); up_read(&sysfs_rename_sem); - - kobject_put(kobj); - kobject_put(target_kobj); - return error; + return error; } static void *sysfs_follow_link(struct dentry *dentry, struct nameidata *nd) diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 718e2e123fae..60717660ac55 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -3,7 +3,7 @@ struct sysfs_elem_dir { }; struct sysfs_elem_symlink { - struct kobject * target_kobj; + struct sysfs_dirent * target_sd; }; struct sysfs_elem_attr { @@ -100,10 +100,11 @@ static inline struct kobject *sysfs_get_kobject(struct dentry *dentry) spin_lock(&dcache_lock); if (!d_unhashed(dentry)) { struct sysfs_dirent * sd = dentry->d_fsdata; + if (sd->s_type & SYSFS_KOBJ_LINK) - kobj = kobject_get(sd->s_elem.symlink.target_kobj); - else - kobj = kobject_get(sd->s_elem.dir.kobj); + sd = sd->s_elem.symlink.target_sd; + + kobj = kobject_get(sd->s_elem.dir.kobj); } spin_unlock(&dcache_lock); |