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From: Jan Kara <jack@suse.cz>
To: Amir Goldstein <amir73il@gmail.com>
Cc: Jan Kara <jack@suse.cz>, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 6/9] fsnotify: pass dir and inode arguments to fsnotify()
Date: Mon, 27 Jul 2020 23:26:34 +0200	[thread overview]
Message-ID: <20200727212634.GI5284@quack2.suse.cz> (raw)
In-Reply-To: <20200722125849.17418-7-amir73il@gmail.com>

On Wed 22-07-20 15:58:46, Amir Goldstein wrote:
> The arguments of fsnotify() are overloaded and mean different things
> for different event types.
> 
> Replace the to_tell argument with separate arguments @dir and @inode,
> because we may be sending to both dir and child.  Using the @data
> argument to pass the child is not enough, because dirent events pass
> this argument (for audit), but we do not report to child.
> 
> Document the new fsnotify() function argumenets.
> 
> Signed-off-by: Amir Goldstein <amir73il@gmail.com>

Thanks, applied!

								Honza

> ---
>  fs/kernfs/file.c                 |  5 +--
>  fs/notify/fsnotify.c             | 54 ++++++++++++++++++++++----------
>  include/linux/fsnotify.h         |  9 +++---
>  include/linux/fsnotify_backend.h | 10 +++---
>  4 files changed, 52 insertions(+), 26 deletions(-)
> 
> diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c
> index 1d185bffc52f..f277d023ebcd 100644
> --- a/fs/kernfs/file.c
> +++ b/fs/kernfs/file.c
> @@ -902,8 +902,9 @@ static void kernfs_notify_workfn(struct work_struct *work)
>  		if (parent) {
>  			p_inode = ilookup(info->sb, kernfs_ino(parent));
>  			if (p_inode) {
> -				fsnotify(p_inode, FS_MODIFY | FS_EVENT_ON_CHILD,
> -					 inode, FSNOTIFY_EVENT_INODE, &name, 0);
> +				fsnotify(FS_MODIFY | FS_EVENT_ON_CHILD,
> +					 inode, FSNOTIFY_EVENT_INODE,
> +					 p_inode, &name, inode, 0);
>  				iput(p_inode);
>  			}
>  
> diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
> index 834775f61f6b..3b805e05c02d 100644
> --- a/fs/notify/fsnotify.c
> +++ b/fs/notify/fsnotify.c
> @@ -179,7 +179,7 @@ int __fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data,
>  	struct dentry *parent;
>  	bool parent_watched = dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED;
>  	__u32 p_mask;
> -	struct inode *p_inode;
> +	struct inode *p_inode = NULL;
>  	struct name_snapshot name;
>  	struct qstr *file_name = NULL;
>  	int ret = 0;
> @@ -213,14 +213,13 @@ int __fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data,
>  		WARN_ON_ONCE(inode != fsnotify_data_inode(data, data_type));
>  
>  		/* Notify both parent and child with child name info */
> -		inode = p_inode;
>  		take_dentry_name_snapshot(&name, dentry);
>  		file_name = &name.name;
>  		mask |= FS_EVENT_ON_CHILD;
>  	}
>  
>  notify:
> -	ret = fsnotify(inode, mask, data, data_type, file_name, 0);
> +	ret = fsnotify(mask, data, data_type, p_inode, file_name, inode, 0);
>  
>  	if (file_name)
>  		release_dentry_name_snapshot(&name);
> @@ -354,18 +353,31 @@ static void fsnotify_iter_next(struct fsnotify_iter_info *iter_info)
>  }
>  
>  /*
> - * This is the main call to fsnotify.  The VFS calls into hook specific functions
> - * in linux/fsnotify.h.  Those functions then in turn call here.  Here will call
> - * out to all of the registered fsnotify_group.  Those groups can then use the
> - * notification event in whatever means they feel necessary.
> + * fsnotify - This is the main call to fsnotify.
> + *
> + * The VFS calls into hook specific functions in linux/fsnotify.h.
> + * Those functions then in turn call here.  Here will call out to all of the
> + * registered fsnotify_group.  Those groups can then use the notification event
> + * in whatever means they feel necessary.
> + *
> + * @mask:	event type and flags
> + * @data:	object that event happened on
> + * @data_type:	type of object for fanotify_data_XXX() accessors
> + * @dir:	optional directory associated with event -
> + *		if @file_name is not NULL, this is the directory that
> + *		@file_name is relative to
> + * @file_name:	optional file name associated with event
> + * @inode:	optional inode associated with event -
> + *		either @dir or @inode must be non-NULL.
> + *		if both are non-NULL event may be reported to both.
> + * @cookie:	inotify rename cookie
>   */
> -int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_type,
> -	     const struct qstr *file_name, u32 cookie)
> +int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir,
> +	     const struct qstr *file_name, struct inode *inode, u32 cookie)
>  {
>  	const struct path *path = fsnotify_data_path(data, data_type);
>  	struct fsnotify_iter_info iter_info = {};
> -	struct super_block *sb = to_tell->i_sb;
> -	struct inode *dir = file_name ? to_tell : NULL;
> +	struct super_block *sb;
>  	struct mount *mnt = NULL;
>  	struct inode *child = NULL;
>  	int ret = 0;
> @@ -374,8 +386,18 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_type,
>  	if (path)
>  		mnt = real_mount(path->mnt);
>  
> -	if (mask & FS_EVENT_ON_CHILD)
> -		child = fsnotify_data_inode(data, data_type);
> +	if (!inode) {
> +		/* Dirent event - report on TYPE_INODE to dir */
> +		inode = dir;
> +	} else if (mask & FS_EVENT_ON_CHILD) {
> +		/*
> +		 * Event on child - report on TYPE_INODE to dir
> +		 * and on TYPE_CHILD to child.
> +		 */
> +		child = inode;
> +		inode = dir;
> +	}
> +	sb = inode->i_sb;
>  
>  	/*
>  	 * Optimization: srcu_read_lock() has a memory barrier which can
> @@ -384,12 +406,12 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_type,
>  	 * SRCU because we have no references to any objects and do not
>  	 * need SRCU to keep them "alive".
>  	 */
> -	if (!to_tell->i_fsnotify_marks && !sb->s_fsnotify_marks &&
> +	if (!inode->i_fsnotify_marks && !sb->s_fsnotify_marks &&
>  	    (!mnt || !mnt->mnt_fsnotify_marks) &&
>  	    (!child || !child->i_fsnotify_marks))
>  		return 0;
>  
> -	marks_mask = to_tell->i_fsnotify_mask | sb->s_fsnotify_mask;
> +	marks_mask = inode->i_fsnotify_mask | sb->s_fsnotify_mask;
>  	if (mnt)
>  		marks_mask |= mnt->mnt_fsnotify_mask;
>  	if (child)
> @@ -407,7 +429,7 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_type,
>  	iter_info.srcu_idx = srcu_read_lock(&fsnotify_mark_srcu);
>  
>  	iter_info.marks[FSNOTIFY_OBJ_TYPE_INODE] =
> -		fsnotify_first_mark(&to_tell->i_fsnotify_marks);
> +		fsnotify_first_mark(&inode->i_fsnotify_marks);
>  	iter_info.marks[FSNOTIFY_OBJ_TYPE_SB] =
>  		fsnotify_first_mark(&sb->s_fsnotify_marks);
>  	if (mnt) {
> diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
> index 01b71ad91339..d9b26c6552ee 100644
> --- a/include/linux/fsnotify.h
> +++ b/include/linux/fsnotify.h
> @@ -23,13 +23,14 @@
>   * have changed (i.e. renamed over).
>   *
>   * Unlike fsnotify_parent(), the event will be reported regardless of the
> - * FS_EVENT_ON_CHILD mask on the parent inode.
> + * FS_EVENT_ON_CHILD mask on the parent inode and will not be reported if only
> + * the child is interested and not the parent.
>   */
>  static inline void fsnotify_name(struct inode *dir, __u32 mask,
>  				 struct inode *child,
>  				 const struct qstr *name, u32 cookie)
>  {
> -	fsnotify(dir, mask, child, FSNOTIFY_EVENT_INODE, name, cookie);
> +	fsnotify(mask, child, FSNOTIFY_EVENT_INODE, dir, name, NULL, cookie);
>  }
>  
>  static inline void fsnotify_dirent(struct inode *dir, struct dentry *dentry,
> @@ -43,7 +44,7 @@ static inline void fsnotify_inode(struct inode *inode, __u32 mask)
>  	if (S_ISDIR(inode->i_mode))
>  		mask |= FS_ISDIR;
>  
> -	fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
> +	fsnotify(mask, inode, FSNOTIFY_EVENT_INODE, NULL, NULL, inode, 0);
>  }
>  
>  /* Notify this dentry's parent about a child's events. */
> @@ -67,7 +68,7 @@ static inline int fsnotify_parent(struct dentry *dentry, __u32 mask,
>  	return __fsnotify_parent(dentry, mask, data, data_type);
>  
>  notify_child:
> -	return fsnotify(inode, mask, data, data_type, NULL, 0);
> +	return fsnotify(mask, data, data_type, NULL, NULL, inode, 0);
>  }
>  
>  /*
> diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
> index d94a50e0445a..32104cfc27a5 100644
> --- a/include/linux/fsnotify_backend.h
> +++ b/include/linux/fsnotify_backend.h
> @@ -398,8 +398,9 @@ struct fsnotify_mark {
>  /* called from the vfs helpers */
>  
>  /* main fsnotify call to send events */
> -extern int fsnotify(struct inode *to_tell, __u32 mask, const void *data,
> -		    int data_type, const struct qstr *name, u32 cookie);
> +extern int fsnotify(__u32 mask, const void *data, int data_type,
> +		    struct inode *dir, const struct qstr *name,
> +		    struct inode *inode, u32 cookie);
>  extern int __fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data,
>  			   int data_type);
>  extern void __fsnotify_inode_delete(struct inode *inode);
> @@ -569,8 +570,9 @@ static inline void fsnotify_init_event(struct fsnotify_event *event,
>  
>  #else
>  
> -static inline int fsnotify(struct inode *to_tell, __u32 mask, const void *data,
> -			   int data_type, const struct qstr *name, u32 cookie)
> +static inline int fsnotify(__u32 mask, const void *data, int data_type,
> +			   struct inode *dir, const struct qstr *name,
> +			   struct inode *inode, u32 cookie)
>  {
>  	return 0;
>  }
> -- 
> 2.17.1
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

  reply	other threads:[~2020-07-27 21:26 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-22 12:58 [PATCH 0/9] Fixes for fanotify name events Amir Goldstein
2020-07-22 12:58 ` [PATCH 1/9] fanotify: fix reporting event to sb/mount marks Amir Goldstein
2020-07-27 15:17   ` Jan Kara
2020-07-22 12:58 ` [PATCH 2/9] inotify: do not set FS_EVENT_ON_CHILD in non-dir mark mask Amir Goldstein
2020-07-27 15:33   ` Jan Kara
2020-07-22 12:58 ` [PATCH 3/9] audit: do not set FS_EVENT_ON_CHILD in audit marks mask Amir Goldstein
2020-07-27 15:33   ` Jan Kara
2020-07-22 12:58 ` [PATCH 4/9] fsnotify: create helper fsnotify_inode() Amir Goldstein
2020-07-27 16:26   ` Jan Kara
2020-07-22 12:58 ` [PATCH 5/9] fsnotify: simplify dir argument to handle_event() Amir Goldstein
2020-07-27 19:32   ` Jan Kara
2020-07-22 12:58 ` [PATCH 6/9] fsnotify: pass dir and inode arguments to fsnotify() Amir Goldstein
2020-07-27 21:26   ` Jan Kara [this message]
2020-07-22 12:58 ` [PATCH 7/9] fsnotify: fix merge with parent mark masks Amir Goldstein
2020-07-27 21:27   ` Jan Kara
2020-07-22 12:58 ` [PATCH 8/9] fsnotify: create method handle_inode_event() in fsnotify_operations Amir Goldstein
2020-07-27 21:27   ` Jan Kara
2020-07-22 12:58 ` [PATCH 9/9] fsnotify: pass inode to fsnotify_parent() Amir Goldstein
2020-07-27 21:29   ` Jan Kara
2020-07-27 21:57 ` [PATCH 0/9] Fixes for fanotify name events Jan Kara

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