Add the following functions to add files to evenfs: eventfs_add_events_file() to add the data needed to create a specific file located at the top level events directory. The dentry/inode will be created when the events directory is scanned. eventfs_add_file() to add the data needed for files within the directories below the top level events directory. The dentry/inode of the file will be created when the directory that the file is in is scanned. Signed-off-by: Ajay Kaher <akaher@xxxxxxxxxx> Co-developed-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Tested-by: Ching-lin Yu <chinglinyu@xxxxxxxxxx> Reported-by: kernel test robot <lkp@xxxxxxxxx> Closes: https://lore.kernel.org/oe-lkp/202305051619.9a469a9a-yujie.liu@xxxxxxxxx --- fs/tracefs/event_inode.c | 86 ++++++++++++++++++++++++++++++++++++++++ include/linux/tracefs.h | 8 ++++ 2 files changed, 94 insertions(+) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 8f334b122e46..9e4843be9dc9 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -209,3 +209,89 @@ struct eventfs_file *eventfs_add_dir(const char *name, mutex_unlock(&eventfs_mutex); return ef; } + +/** + * eventfs_add_events_file - add the data needed to create a file for later reference + * @name: the name of the file to create. + * @mode: the permission that the file should have. + * @parent: parent dentry for this file. + * @data: something that the caller will want to get to later on. + * @fop: struct file_operations that should be used for this file. + * + * This function is used to add the information needed to create a + * dentry/inode within the top level events directory. The file created + * will have the @mode permissions. The @data will be used to fill the + * inode.i_private when the open() call is done. The dentry and inodes are + * all created when they are referenced, and removed when they are no + * longer referenced. + */ +int eventfs_add_events_file(const char *name, umode_t mode, + struct dentry *parent, void *data, + const struct file_operations *fop) +{ + struct tracefs_inode *ti; + struct eventfs_inode *ei; + struct eventfs_file *ef; + + if (!parent) + return -EINVAL; + + if (!(mode & S_IFMT)) + mode |= S_IFREG; + + if (!parent->d_inode) + return -EINVAL; + + ti = get_tracefs(parent->d_inode); + if (!(ti->flags & TRACEFS_EVENT_INODE)) + return -EINVAL; + + ei = ti->private; + ef = eventfs_prepare_ef(name, mode, fop, NULL, data); + + if (IS_ERR(ef)) + return -ENOMEM; + + mutex_lock(&eventfs_mutex); + list_add_tail(&ef->list, &ei->e_top_files); + mutex_unlock(&eventfs_mutex); + return 0; +} + +/** + * eventfs_add_file - add eventfs file to list to create later + * @name: the name of the file to create. + * @mode: the permission that the file should have. + * @ef_parent: parent eventfs_file for this file. + * @data: something that the caller will want to get to later on. + * @fop: struct file_operations that should be used for this file. + * + * This function is used to add the information needed to create a + * file within a subdirectory of the events directory. The file created + * will have the @mode permissions. The @data will be used to fill the + * inode.i_private when the open() call is done. The dentry and inodes are + * all created when they are referenced, and removed when they are no + * longer referenced. + */ +int eventfs_add_file(const char *name, umode_t mode, + struct eventfs_file *ef_parent, + void *data, + const struct file_operations *fop) +{ + struct eventfs_file *ef; + + if (!ef_parent) + return -EINVAL; + + if (!(mode & S_IFMT)) + mode |= S_IFREG; + + ef = eventfs_prepare_ef(name, mode, fop, NULL, data); + if (IS_ERR(ef)) + return -ENOMEM; + + mutex_lock(&eventfs_mutex); + list_add_tail(&ef->list, &ef_parent->ei->e_top_files); + mutex_unlock(&eventfs_mutex); + return 0; +} diff --git a/include/linux/tracefs.h b/include/linux/tracefs.h index 432e5e6f7901..54c9cbd0389b 100644 --- a/include/linux/tracefs.h +++ b/include/linux/tracefs.h @@ -32,6 +32,14 @@ struct eventfs_file *eventfs_add_subsystem_dir(const char *name, struct eventfs_file *eventfs_add_dir(const char *name, struct eventfs_file *ef_parent); +int eventfs_add_file(const char *name, umode_t mode, + struct eventfs_file *ef_parent, void *data, + const struct file_operations *fops); + +int eventfs_add_events_file(const char *name, umode_t mode, + struct dentry *parent, void *data, + const struct file_operations *fops); + struct dentry *tracefs_create_file(const char *name, umode_t mode, struct dentry *parent, void *data, const struct file_operations *fops); -- 2.39.0
