From htejun@gmail.com Wed Jun 13 12:27:32 2007 From: Tejun Heo Cc: Tejun Heo Subject: [PATCH 04/11] sysfs: implement sysfs_find_dirent() and sysfs_get_dirent() Date: Thu, 14 Jun 2007 04:27:22 +0900 Message-Id: <11817628422159-git-send-email-htejun@gmail.com> To: greg@kroah.com, dmitry.torokhov@gmail.com, cornelia.huck@de.ibm.com, oneukum@suse.de, rpurdie@rpsys.net, stern@rowland.harvard.edu, maneesh@in.ibm.com, linux-kernel@vger.kernel.org, htejun@gmail.com From: Tejun Heo Implement sysfs_find_dirent() and sysfs_get_dirent(). sysfs_dirent_exist() is replaced by sysfs_find_dirent(). These will be used to make directory entries reclamiable. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 61 ++++++++++++++++++++++++++++++++++++++--------------- fs/sysfs/file.c | 2 - fs/sysfs/symlink.c | 2 - fs/sysfs/sysfs.h | 5 +++- 4 files changed, 50 insertions(+), 20 deletions(-) --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -317,28 +317,55 @@ void sysfs_attach_dirent(struct sysfs_di } } -/* +/** + * sysfs_find_dirent - find sysfs_dirent with the given name + * @parent_sd: sysfs_dirent to search under + * @name: name to look for + * + * Look for sysfs_dirent with name @name under @parent_sd. * - * Return -EEXIST if there is already a sysfs element with the same name for - * the same parent. + * LOCKING: + * mutex_lock(parent->i_mutex) * - * called with parent inode's i_mutex held + * RETURNS: + * Pointer to sysfs_dirent if found, NULL if not. */ -int sysfs_dirent_exist(struct sysfs_dirent *parent_sd, - const unsigned char *new) +struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, + const unsigned char *name) { - struct sysfs_dirent * sd; + struct sysfs_dirent *sd; - for (sd = parent_sd->s_children; sd; sd = sd->s_sibling) { - if (sysfs_type(sd)) { - if (strcmp(sd->s_name, new)) - continue; - else - return -EEXIST; - } - } + for (sd = parent_sd->s_children; sd; sd = sd->s_sibling) + if (sysfs_type(sd) && !strcmp(sd->s_name, name)) + return sd; + return NULL; +} - return 0; +/** + * sysfs_get_dirent - find and get sysfs_dirent with the given name + * @parent_sd: sysfs_dirent to search under + * @name: name to look for + * + * Look for sysfs_dirent with name @name under @parent_sd and get + * it if found. + * + * LOCKING: + * Kernel thread context (may sleep) + * + * RETURNS: + * Pointer to sysfs_dirent if found, NULL if not. + */ +struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd, + const unsigned char *name) +{ + struct sysfs_dirent *sd; + + mutex_lock(&parent_sd->s_dentry->d_inode->i_mutex); + sd = sysfs_find_dirent(parent_sd, name); + sysfs_get(sd); + mutex_unlock(&parent_sd->s_dentry->d_inode->i_mutex); + + return sd; } static int create_dir(struct kobject *kobj, struct dentry *parent, @@ -382,7 +409,7 @@ static int create_dir(struct kobject *ko /* link in */ error = -EEXIST; - if (sysfs_dirent_exist(parent->d_fsdata, name)) + if (sysfs_find_dirent(parent->d_fsdata, name)) goto out_iput; sysfs_instantiate(dentry, inode); --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -421,7 +421,7 @@ int sysfs_add_file(struct dentry * dir, mutex_lock(&dir->d_inode->i_mutex); - if (sysfs_dirent_exist(parent_sd, attr->name)) { + if (sysfs_find_dirent(parent_sd, attr->name)) { error = -EEXIST; goto out_unlock; } --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -95,7 +95,7 @@ int sysfs_create_link(struct kobject * k return -ENOENT; mutex_lock(&dentry->d_inode->i_mutex); - if (!sysfs_dirent_exist(dentry->d_fsdata, name)) + if (!sysfs_find_dirent(dentry->d_fsdata, name)) error = sysfs_add_link(parent_sd, name, target_sd); mutex_unlock(&dentry->d_inode->i_mutex); --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -59,7 +59,10 @@ extern struct inode * sysfs_get_inode(st extern void sysfs_instantiate(struct dentry *dentry, struct inode *inode); extern void release_sysfs_dirent(struct sysfs_dirent * sd); -extern int sysfs_dirent_exist(struct sysfs_dirent *, const unsigned char *); +extern struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, + const unsigned char *name); +extern struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd, + const unsigned char *name); extern struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type); extern void sysfs_attach_dirent(struct sysfs_dirent *sd,