static int sysfs_do_create_link(struct kobject *kobj, struct kobject *target, const char *name, int warn) { struct sysfs_dirent *parent_sd = NULL; struct sysfs_dirent *target_sd = NULL; struct sysfs_dirent *sd = NULL; struct sysfs_addrm_cxt acxt; int error; BUG_ON(!name); if (!kobj) parent_sd = &sysfs_root; else parent_sd = kobj->sd; error = -EFAULT; if (!parent_sd) goto out_put; /* target->sd can go away beneath us but is protected with * sysfs_assoc_lock. Fetch target_sd from it. */ spin_lock(&sysfs_assoc_lock); if (target->sd) target_sd = sysfs_get(target->sd); spin_unlock(&sysfs_assoc_lock); error = -ENOENT; if (!target_sd) goto out_put; error = -ENOMEM; sd = sysfs_new_dirent(name, S_IFLNK|S_IRWXUGO, SYSFS_KOBJ_LINK); if (!sd) goto out_put; sd->s_symlink.target_sd = target_sd; target_sd = NULL; /* reference is now owned by the symlink */ sysfs_addrm_start(&acxt, parent_sd); if (warn) error = sysfs_add_one(&acxt, sd); else error = __sysfs_add_one(&acxt, sd); sysfs_addrm_finish(&acxt); if (error) goto out_put; return 0; out_put: sysfs_put(target_sd); sysfs_put(sd); return error; }
/** * sysfs_add_one - add sysfs_dirent to parent * @acxt: addrm context to use * @sd: sysfs_dirent to be added * @parent_sd: the parent sysfs_dirent to add @sd to * * Get @parent_sd and set @sd->s_parent to it and increment nlink of * the parent inode if @sd is a directory and link into the children * list of the parent. * * This function should be called between calls to * sysfs_addrm_start() and sysfs_addrm_finish() and should be * passed the same @acxt as passed to sysfs_addrm_start(). * * LOCKING: * Determined by sysfs_addrm_start(). * * RETURNS: * 0 on success, -EEXIST if entry with the given name already * exists. */ int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd, struct sysfs_dirent *parent_sd) { int ret; ret = __sysfs_add_one(acxt, sd, parent_sd); if (ret == -EEXIST) sysfs_warn_dup(parent_sd, sd->s_name); return ret; }
/** * sysfs_add_one - add sysfs_dirent to parent * @acxt: addrm context to use * @sd: sysfs_dirent to be added * * Get @acxt->parent_sd 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. * * This function should be called between calls to * sysfs_addrm_start() and sysfs_addrm_finish() and should be * passed the same @acxt as passed to sysfs_addrm_start(). * * LOCKING: * Determined by sysfs_addrm_start(). * * RETURNS: * 0 on success, -EEXIST if entry with the given name already * exists. */ int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) { int ret; ret = __sysfs_add_one(acxt, sd); if (ret == -EEXIST) { char *path = kzalloc(PATH_MAX, GFP_KERNEL); WARN(1, KERN_WARNING "sysfs: cannot create duplicate filename '%s'\n", (path == NULL) ? sd->s_name : strcat(strcat(sysfs_pathname(acxt->parent_sd, path), "/"), sd->s_name)); kfree(path); } return ret; }