Adding following function to eventfs to add files: eventfs_add_top_file() adds the information of top file to eventfs and dynamically creates these files as and when required. eventfs_add_file() adds the information of nested files to eventfs and dynamically creates these dir as and when required. 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> Link: https://lore.kernel.org/oe-lkp/202305051619.9a469a9a-yujie.liu@xxxxxxxxx --- fs/tracefs/event_inode.c | 94 ++++++++++++++++++++++++++++++++++++++++ include/linux/tracefs.h | 8 ++++ 2 files changed, 102 insertions(+) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index a48ce23c0..17afb7476 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -270,3 +270,97 @@ struct eventfs_file *eventfs_add_dir(const char *name, eventfs_up_write(eventfs_rwsem); return ef; } + +/** + * eventfs_add_top_file - add event top file to list to create later + * @name: a pointer to a string containing the name of the file to create. + * @mode: the permission that the file should have. + * @parent: a pointer to the parent dentry for this file. This should be a + * directory dentry if set. If this parameter is NULL, then the + * file will be created in the root of the tracefs filesystem. + * @data: a pointer to something that the caller will want to get to later + * on. The inode.i_private pointer will point to this value on + * the open() call. + * @fop: a pointer to a struct file_operations that should be used for + * this file. + * + * This function adds top files of event dir to list. + * And all these files are created on the fly when they are looked up, + * and the dentry and inodes will be removed when they are done. + */ +int eventfs_add_top_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; + struct rw_semaphore *eventfs_rwsem; + + 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; + + eventfs_rwsem = (struct rw_semaphore *) parent->d_inode->i_private; + eventfs_down_write(eventfs_rwsem); + list_add_tail(&ef->list, &ei->e_top_files); + ef->d_parent = parent; + eventfs_up_write(eventfs_rwsem); + return 0; +} + +/** + * eventfs_add_file - add eventfs file to list to create later + * @name: a pointer to a string containing the name of the file to create. + * @mode: the permission that the file should have. + * @ef_parent: a pointer to the parent eventfs_file for this file. + * @data: a pointer to something that the caller will want to get to later + * on. The inode.i_private pointer will point to this value on + * the open() call. + * @fop: a pointer to a struct file_operations that should be used for + * this file. + * + * This function adds top files of event dir to list. + * And all these files are created on the fly when they are looked up, + * and the dentry and inodes will be removed when they are done. + */ +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; + struct rw_semaphore *eventfs_rwsem; + + 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; + + eventfs_rwsem = (struct rw_semaphore *) ef_parent->data; + eventfs_down_write(eventfs_rwsem); + list_add_tail(&ef->list, &ef_parent->ei->e_top_files); + ef->d_parent = ef_parent->dentry; + eventfs_up_write(eventfs_rwsem); + return 0; +} diff --git a/include/linux/tracefs.h b/include/linux/tracefs.h index aeca6761f..1e1780a61 100644 --- a/include/linux/tracefs.h +++ b/include/linux/tracefs.h @@ -50,6 +50,14 @@ struct eventfs_file *eventfs_add_dir(const char *name, struct eventfs_file *ef_parent, struct rw_semaphore *eventfs_rwsem); +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_top_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); -- 2.40.0
