From htejun@gmail.com Thu Aug 2 14:30:25 2007 From: Tejun Heo Date: Thu, 2 Aug 2007 21:38:03 +0900 Subject: [PATCH 3/5] sysfs: make sysfs_add/remove_one() call link/unlink_sibling() implictly To: ebiederm@xmission.com, gregkh@suse.de, linux-kernel@vger.kernel.org, satyam@infradead.org, cornelia.huck@de.ibm.com, stern@rowland.harvard.edu, htejun@gmail.com Cc: Tejun Heo Message-ID: <11860582831967-git-send-email-htejun@gmail.com> When adding or removing a sysfs_dirent, the user used to be required to call link/unlink separately. It was for two reasons - code looked like that before sysfs_addrm_cxt conversion and to avoid looping through parent_sd->children list twice during removal. Performance optimization during removal just isn't worth it. Make sysfs_add/remove_one() call sysfs_link/unlink_sibing() implicitly. This makes code simpler albeit slightly less efficient. This change doesn't introduce any noticeable behavior change. Signed-off-by: Tejun Heo Acked-by: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 21 ++++++++++----------- fs/sysfs/file.c | 4 +--- fs/sysfs/inode.c | 17 ++++------------- fs/sysfs/symlink.c | 4 +--- fs/sysfs/sysfs.h | 2 -- 5 files changed, 16 insertions(+), 32 deletions(-) --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -30,7 +30,7 @@ static DEFINE_IDA(sysfs_ino_ida); * Locking: * mutex_lock(sysfs_mutex) */ -void sysfs_link_sibling(struct sysfs_dirent *sd) +static void sysfs_link_sibling(struct sysfs_dirent *sd) { struct sysfs_dirent *parent_sd = sd->s_parent; @@ -49,7 +49,7 @@ void sysfs_link_sibling(struct sysfs_dir * Locking: * mutex_lock(sysfs_mutex) */ -void sysfs_unlink_sibling(struct sysfs_dirent *sd) +static void sysfs_unlink_sibling(struct sysfs_dirent *sd) { struct sysfs_dirent **pos; @@ -500,6 +500,8 @@ void sysfs_add_one(struct sysfs_addrm_cx inc_nlink(acxt->parent_inode); acxt->cnt++; + + sysfs_link_sibling(sd); } /** @@ -521,7 +523,9 @@ void sysfs_add_one(struct sysfs_addrm_cx */ void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) { - BUG_ON(sd->s_sibling || (sd->s_flags & SYSFS_FLAG_REMOVED)); + BUG_ON(sd->s_flags & SYSFS_FLAG_REMOVED); + + sysfs_unlink_sibling(sd); sd->s_flags |= SYSFS_FLAG_REMOVED; sd->s_sibling = acxt->removed; @@ -697,10 +701,8 @@ static int create_dir(struct kobject *ko /* link in */ sysfs_addrm_start(&acxt, parent_sd); - if (!sysfs_find_dirent(parent_sd, name)) { + if (!sysfs_find_dirent(parent_sd, name)) sysfs_add_one(&acxt, sd); - sysfs_link_sibling(sd); - } if (!sysfs_addrm_finish(&acxt)) { sysfs_put(sd); @@ -821,7 +823,6 @@ static void remove_dir(struct sysfs_dire struct sysfs_addrm_cxt acxt; sysfs_addrm_start(&acxt, sd->s_parent); - sysfs_unlink_sibling(sd); sysfs_remove_one(&acxt, sd); sysfs_addrm_finish(&acxt); } @@ -846,11 +847,9 @@ static void __sysfs_remove_dir(struct sy while (*pos) { struct sysfs_dirent *sd = *pos; - if (sysfs_type(sd) && sysfs_type(sd) != SYSFS_DIR) { - *pos = sd->s_sibling; - sd->s_sibling = NULL; + if (sysfs_type(sd) && sysfs_type(sd) != SYSFS_DIR) sysfs_remove_one(&acxt, sd); - } else + else pos = &(*pos)->s_sibling; } sysfs_addrm_finish(&acxt); --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -405,10 +405,8 @@ int sysfs_add_file(struct sysfs_dirent * sysfs_addrm_start(&acxt, dir_sd); - if (!sysfs_find_dirent(dir_sd, attr->name)) { + if (!sysfs_find_dirent(dir_sd, attr->name)) sysfs_add_one(&acxt, sd); - sysfs_link_sibling(sd); - } if (!sysfs_addrm_finish(&acxt)) { sysfs_put(sd); --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -189,25 +189,16 @@ void sysfs_instantiate(struct dentry *de int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name) { struct sysfs_addrm_cxt acxt; - struct sysfs_dirent **pos, *sd; + struct sysfs_dirent *sd; if (!dir_sd) return -ENOENT; sysfs_addrm_start(&acxt, dir_sd); - for (pos = &dir_sd->s_children; *pos; pos = &(*pos)->s_sibling) { - sd = *pos; - - if (!sysfs_type(sd)) - continue; - if (!strcmp(sd->s_name, name)) { - *pos = sd->s_sibling; - sd->s_sibling = NULL; - sysfs_remove_one(&acxt, sd); - break; - } - } + sd = sysfs_find_dirent(dir_sd, name); + if (sd) + sysfs_remove_one(&acxt, sd); if (sysfs_addrm_finish(&acxt)) return 0; --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -92,10 +92,8 @@ int sysfs_create_link(struct kobject * k sysfs_addrm_start(&acxt, parent_sd); - if (!sysfs_find_dirent(parent_sd, name)) { + if (!sysfs_find_dirent(parent_sd, name)) sysfs_add_one(&acxt, sd); - sysfs_link_sibling(sd); - } if (!sysfs_addrm_finish(&acxt)) { error = -EEXIST; --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -56,8 +56,6 @@ extern struct sysfs_dirent sysfs_root; extern struct kmem_cache *sysfs_dir_cachep; extern struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd); -extern void sysfs_link_sibling(struct sysfs_dirent *sd); -extern void sysfs_unlink_sibling(struct sysfs_dirent *sd); extern struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd); extern void sysfs_put_active(struct sysfs_dirent *sd); extern struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd);