Adding following functions to eventfs: eventfs_set_ef_status_free() eventfs_post_create_dir() eventfs_root_lookup() eventfs_release() dcache_dir_open_wrapper()
Signed-off-by: Ajay Kaher akaher@vmware.com Co-developed-by: Steven Rostedt (VMware) rostedt@goodmis.org Signed-off-by: Steven Rostedt (VMware) rostedt@goodmis.org Tested-by: Ching-lin Yu chinglinyu@google.com --- fs/tracefs/event_inode.c | 188 +++++++++++++++++++++++++++++++++++++++ include/linux/tracefs.h | 2 + 2 files changed, 190 insertions(+)
diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 0ee27f7c8..f047e45ed 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -208,10 +208,198 @@ static struct dentry *eventfs_create_dir(const char *name, umode_t mode, return eventfs_end_creating(dentry); }
+/** + * eventfs_set_ef_status_free - set the ef->status to free + * @dentry: dentry who's status to be freed + * + * eventfs_set_ef_status_free will be called if no more + * reference remains + */ +void eventfs_set_ef_status_free(struct dentry *dentry) +{ + struct tracefs_inode *ti_parent; + struct eventfs_file *ef; + + ti_parent = get_tracefs(dentry->d_parent->d_inode); + if (!ti_parent || !(ti_parent->flags & TRACEFS_EVENT_INODE)) + return; + + ef = dentry->d_fsdata; + if (!ef) + return; + ef->created = false; + ef->dentry = NULL; +} + +/** + * eventfs_post_create_dir - post create dir routine + * @ef: eventfs_file of recently created dir + * + * Files with-in eventfs dir should know dentry of parent dir + */ +static void eventfs_post_create_dir(struct eventfs_file *ef) +{ + struct eventfs_file *ef_child; + struct tracefs_inode *ti; + + eventfs_down_read((struct rw_semaphore *) ef->data); + /* fill parent-child relation */ + list_for_each_entry(ef_child, &ef->ei->e_top_files, list) { + ef_child->d_parent = ef->dentry; + } + eventfs_up_read((struct rw_semaphore *) ef->data); + + ti = get_tracefs(ef->dentry->d_inode); + ti->private = ef->ei; +} + +/** + * eventfs_root_lookup - lookup routine to create file/dir + * @dir: directory in which lookup to be done + * @dentry: file/dir dentry + * @flags: + * + * Used to create dynamic file/dir with-in @dir, search with-in ei + * list, if @dentry found go ahead and create the file/dir + */ + +static struct dentry *eventfs_root_lookup(struct inode *dir, + struct dentry *dentry, + unsigned int flags) +{ + struct tracefs_inode *ti; + struct eventfs_inode *ei; + struct eventfs_file *ef; + struct dentry *ret = NULL; + struct rw_semaphore *eventfs_rwsem; + + ti = get_tracefs(dir); + if (!(ti->flags & TRACEFS_EVENT_INODE)) + return NULL; + + ei = ti->private; + eventfs_rwsem = (struct rw_semaphore *) dir->i_private; + eventfs_down_read(eventfs_rwsem); + list_for_each_entry(ef, &ei->e_top_files, list) { + if (strcmp(ef->name, dentry->d_name.name)) + continue; + ret = simple_lookup(dir, dentry, flags); + if (ef->created) + continue; + ef->created = true; + if (ef->ei) + ef->dentry = eventfs_create_dir(ef->name, ef->mode, ef->d_parent, + ef->data, ef->fop, ef->iop); + else + ef->dentry = eventfs_create_file(ef->name, ef->mode, ef->d_parent, + ef->data, ef->fop); + + if (IS_ERR_OR_NULL(ef->dentry)) { + ef->created = false; + } else { + if (ef->ei) + eventfs_post_create_dir(ef); + ef->dentry->d_fsdata = ef; + dput(ef->dentry); + } + break; + } + eventfs_up_read(eventfs_rwsem); + return ret; +} + +/** + * eventfs_release - called to release eventfs file/dir + * @inode: inode to be released + * @file: file to be released (not used) + */ +static int eventfs_release(struct inode *inode, struct file *file) +{ + struct tracefs_inode *ti; + struct eventfs_inode *ei; + struct eventfs_file *ef; + struct dentry *dentry = file_dentry(file); + struct rw_semaphore *eventfs_rwsem; + + ti = get_tracefs(inode); + if (!(ti->flags & TRACEFS_EVENT_INODE)) + return -EINVAL; + + ei = ti->private; + eventfs_rwsem = eventfs_dentry_to_rwsem(dentry); + eventfs_down_read(eventfs_rwsem); + list_for_each_entry(ef, &ei->e_top_files, list) { + if (ef->created) + dput(ef->dentry); + } + eventfs_up_read(eventfs_rwsem); + return dcache_dir_close(inode, file); +} + +/** + * dcache_dir_open_wrapper - eventfs open wrapper + * @inode: not used + * @file: dir to be opened (to create it's child) + * + * Used to dynamic create file/dir with-in @file, all the + * file/dir will be created. If already created then reference + * will be increased + */ +static int dcache_dir_open_wrapper(struct inode *inode, struct file *file) +{ + struct tracefs_inode *ti; + struct eventfs_inode *ei; + struct eventfs_file *ef; + struct inode *f_inode = file_inode(file); + struct dentry *dentry = file_dentry(file); + struct rw_semaphore *eventfs_rwsem; + + ti = get_tracefs(f_inode); + if (!(ti->flags & TRACEFS_EVENT_INODE)) + return -EINVAL; + + ei = ti->private; + eventfs_rwsem = eventfs_dentry_to_rwsem(dentry); + eventfs_down_read(eventfs_rwsem); + list_for_each_entry(ef, &ei->e_top_files, list) { + if (ef->created) { + dget(ef->dentry); + continue; + } + + ef->created = true; + + inode_lock(dentry->d_inode); + if (ef->ei) + ef->dentry = eventfs_create_dir(ef->name, ef->mode, dentry, + ef->data, ef->fop, ef->iop); + else + ef->dentry = eventfs_create_file(ef->name, ef->mode, dentry, + ef->data, ef->fop); + inode_unlock(dentry->d_inode); + + if (IS_ERR_OR_NULL(ef->dentry)) { + ef->created = false; + } else { + if (ef->ei) + eventfs_post_create_dir(ef); + ef->dentry->d_fsdata = ef; + } + } + eventfs_up_read(eventfs_rwsem); + return dcache_dir_open(inode, file); +} + static const struct file_operations eventfs_file_operations = { + .open = dcache_dir_open_wrapper, + .read = generic_read_dir, + .iterate_shared = dcache_readdir, + .llseek = generic_file_llseek, + .release = eventfs_release, };
static const struct inode_operations eventfs_root_dir_inode_operations = { + .lookup = eventfs_root_lookup, };
/** diff --git a/include/linux/tracefs.h b/include/linux/tracefs.h index 57bfd1322..268450d60 100644 --- a/include/linux/tracefs.h +++ b/include/linux/tracefs.h @@ -68,6 +68,8 @@ void eventfs_remove(struct eventfs_file *ef);
void eventfs_remove_events_dir(struct dentry *dentry);
+void eventfs_set_ef_status_free(struct dentry *dentry); + struct dentry *tracefs_create_file(const char *name, umode_t mode, struct dentry *parent, void *data, const struct file_operations *fops);