diff mbox series

[v5,11/18] fanotify: add a helper to check for pre content events

Message ID 288ff84b68a6b79a0526b6d53df2df5d184b5232.1725481503.git.josef@toxicpanda.com (mailing list archive)
State New, archived
Headers show
Series fanotify: add pre-content hooks | expand

Commit Message

Josef Bacik Sept. 4, 2024, 8:28 p.m. UTC 
We want to emit events during page fault, and calling into fanotify
could be expensive, so add a helper to allow us to skip calling into
fanotify from page fault.  This will also be used to disable readahead
for content watched files which will be handled in a subsequent patch.

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/notify/fsnotify.c             | 15 +++++++++++++++
 include/linux/fsnotify_backend.h | 14 ++++++++++++++
 2 files changed, 29 insertions(+)

Comments

Amir Goldstein Sept. 5, 2024, 8:09 a.m. UTC | #1 
On Wed, Sep 4, 2024 at 10:29 PM Josef Bacik <josef@toxicpanda.com> wrote:
>
> We want to emit events during page fault, and calling into fanotify
> could be expensive, so add a helper to allow us to skip calling into
> fanotify from page fault.  This will also be used to disable readahead
> for content watched files which will be handled in a subsequent patch.
>
> Reviewed-by: Christian Brauner <brauner@kernel.org>
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>

Reviewed-by: Amir Goldstein <amir73il@gmail.com>

Thanks,
Amir.

> ---
>  fs/notify/fsnotify.c             | 15 +++++++++++++++
>  include/linux/fsnotify_backend.h | 14 ++++++++++++++
>  2 files changed, 29 insertions(+)
>
> diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
> index 1ca4a8da7f29..30badf8ba36c 100644
> --- a/fs/notify/fsnotify.c
> +++ b/fs/notify/fsnotify.c
> @@ -201,6 +201,21 @@ static inline bool fsnotify_object_watched(struct inode *inode, __u32 mnt_mask,
>         return mask & marks_mask & ALL_FSNOTIFY_EVENTS;
>  }
>
> +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
> +bool fsnotify_file_has_pre_content_watches(struct file *file)
> +{
> +       struct inode *inode = file_inode(file);
> +       __u32 mnt_mask = real_mount(file->f_path.mnt)->mnt_fsnotify_mask;
> +
> +       if (!(inode->i_sb->s_type->fs_flags & FS_ALLOW_HSM))
> +               return false;
> +
> +       return fsnotify_object_watched(inode, mnt_mask,
> +                                      FSNOTIFY_PRE_CONTENT_EVENTS);
> +}
> +#endif
> +
> +
>  /*
>   * Notify this dentry's parent about a child's events with child name info
>   * if parent is watching or if inode/sb/mount are interested in events with
> diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
> index 276320846bfd..b495a0676dd3 100644
> --- a/include/linux/fsnotify_backend.h
> +++ b/include/linux/fsnotify_backend.h
> @@ -900,6 +900,15 @@ static inline void fsnotify_init_event(struct fsnotify_event *event)
>         INIT_LIST_HEAD(&event->list);
>  }
>
> +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
> +bool fsnotify_file_has_pre_content_watches(struct file *file);
> +#else
> +static inline bool fsnotify_file_has_pre_content_watches(struct file *file)
> +{
> +       return false;
> +}
> +#endif /* CONFIG_FANOTIFY_ACCESS_PERMISSIONS */
> +
>  #else
>
>  static inline int fsnotify(__u32 mask, const void *data, int data_type,
> @@ -938,6 +947,11 @@ static inline u32 fsnotify_get_cookie(void)
>  static inline void fsnotify_unmount_inodes(struct super_block *sb)
>  {}
>
> +static inline bool fsnotify_file_has_pre_content_watches(struct file *file)
> +{
> +       return false;
> +}
> +
>  #endif /* CONFIG_FSNOTIFY */
>
>  #endif /* __KERNEL __ */
> --
> 2.43.0
>
diff mbox series

Patch

diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 1ca4a8da7f29..30badf8ba36c 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -201,6 +201,21 @@  static inline bool fsnotify_object_watched(struct inode *inode, __u32 mnt_mask,
 	return mask & marks_mask & ALL_FSNOTIFY_EVENTS;
 }
 
+#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+bool fsnotify_file_has_pre_content_watches(struct file *file)
+{
+	struct inode *inode = file_inode(file);
+	__u32 mnt_mask = real_mount(file->f_path.mnt)->mnt_fsnotify_mask;
+
+	if (!(inode->i_sb->s_type->fs_flags & FS_ALLOW_HSM))
+		return false;
+
+	return fsnotify_object_watched(inode, mnt_mask,
+				       FSNOTIFY_PRE_CONTENT_EVENTS);
+}
+#endif
+
+
 /*
  * Notify this dentry's parent about a child's events with child name info
  * if parent is watching or if inode/sb/mount are interested in events with
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 276320846bfd..b495a0676dd3 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -900,6 +900,15 @@  static inline void fsnotify_init_event(struct fsnotify_event *event)
 	INIT_LIST_HEAD(&event->list);
 }
 
+#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+bool fsnotify_file_has_pre_content_watches(struct file *file);
+#else
+static inline bool fsnotify_file_has_pre_content_watches(struct file *file)
+{
+	return false;
+}
+#endif /* CONFIG_FANOTIFY_ACCESS_PERMISSIONS */
+
 #else
 
 static inline int fsnotify(__u32 mask, const void *data, int data_type,
@@ -938,6 +947,11 @@  static inline u32 fsnotify_get_cookie(void)
 static inline void fsnotify_unmount_inodes(struct super_block *sb)
 {}
 
+static inline bool fsnotify_file_has_pre_content_watches(struct file *file)
+{
+	return false;
+}
+
 #endif	/* CONFIG_FSNOTIFY */
 
 #endif	/* __KERNEL __ */