diff mbox series

[v5,06/18] fanotify: pass optional file access range in pre-content event

Message ID 87325af81514d7bd0b2236e14c613b7160651bda.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, 8:27 p.m. UTC 
From: Amir Goldstein <amir73il@gmail.com>

We would like to add file range information to pre-content events.

Pass a struct file_range with optional offset and length to event handler
along with pre-content permission event.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
 fs/notify/fanotify/fanotify.c    | 10 ++++++++--
 fs/notify/fanotify/fanotify.h    |  2 ++
 include/linux/fsnotify.h         | 17 ++++++++++++++++-
 include/linux/fsnotify_backend.h | 32 ++++++++++++++++++++++++++++++++
 4 files changed, 58 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index b163594843f5..4e8dce39fa8f 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -549,9 +549,13 @@  static struct fanotify_event *fanotify_alloc_path_event(const struct path *path,
 	return &pevent->fae;
 }
 
-static struct fanotify_event *fanotify_alloc_perm_event(const struct path *path,
+static struct fanotify_event *fanotify_alloc_perm_event(const void *data,
+							int data_type,
 							gfp_t gfp)
 {
+	const struct path *path = fsnotify_data_path(data, data_type);
+	const struct file_range *range =
+			    fsnotify_data_file_range(data, data_type);
 	struct fanotify_perm_event *pevent;
 
 	pevent = kmem_cache_alloc(fanotify_perm_event_cachep, gfp);
@@ -565,6 +569,8 @@  static struct fanotify_event *fanotify_alloc_perm_event(const struct path *path,
 	pevent->hdr.len = 0;
 	pevent->state = FAN_EVENT_INIT;
 	pevent->path = *path;
+	pevent->ppos = range ? range->ppos : NULL;
+	pevent->count = range ? range->count : 0;
 	path_get(path);
 
 	return &pevent->fae;
@@ -802,7 +808,7 @@  static struct fanotify_event *fanotify_alloc_event(
 	old_memcg = set_active_memcg(group->memcg);
 
 	if (fanotify_is_perm_event(mask)) {
-		event = fanotify_alloc_perm_event(path, gfp);
+		event = fanotify_alloc_perm_event(data, data_type, gfp);
 	} else if (fanotify_is_error_event(mask)) {
 		event = fanotify_alloc_error_event(group, fsid, data,
 						   data_type, &hash);
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index e5ab33cae6a7..93598b7d5952 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -425,6 +425,8 @@  FANOTIFY_PE(struct fanotify_event *event)
 struct fanotify_perm_event {
 	struct fanotify_event fae;
 	struct path path;
+	const loff_t *ppos;		/* optional file range info */
+	size_t count;
 	u32 response;			/* userspace answer to the event */
 	unsigned short state;		/* state of the event */
 	int fd;		/* fd we passed to userspace for this event */
diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
index fb3837b8de4c..9d001d328619 100644
--- a/include/linux/fsnotify.h
+++ b/include/linux/fsnotify.h
@@ -132,6 +132,21 @@  static inline int fsnotify_file(struct file *file, __u32 mask)
 }
 
 #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+static inline int fsnotify_file_range(struct file *file, __u32 mask,
+				      const loff_t *ppos, size_t count)
+{
+	struct file_range range;
+
+	if (file->f_mode & FMODE_NONOTIFY)
+		return 0;
+
+	range.path = &file->f_path;
+	range.ppos = ppos;
+	range.count = count;
+	return fsnotify_parent(range.path->dentry, mask, &range,
+			       FSNOTIFY_EVENT_FILE_RANGE);
+}
+
 /*
  * fsnotify_file_area_perm - permission hook before access/modify of file range
  */
@@ -175,7 +190,7 @@  static inline int fsnotify_file_area_perm(struct file *file, int perm_mask,
 	else
 		return 0;
 
-	return fsnotify_file(file, fsnotify_mask);
+	return fsnotify_file_range(file, fsnotify_mask, ppos, count);
 }
 
 /*
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 200a5e3b1cd4..276320846bfd 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -298,6 +298,7 @@  static inline void fsnotify_group_assert_locked(struct fsnotify_group *group)
 /* When calling fsnotify tell it if the data is a path or inode */
 enum fsnotify_data_type {
 	FSNOTIFY_EVENT_NONE,
+	FSNOTIFY_EVENT_FILE_RANGE,
 	FSNOTIFY_EVENT_PATH,
 	FSNOTIFY_EVENT_INODE,
 	FSNOTIFY_EVENT_DENTRY,
@@ -310,6 +311,17 @@  struct fs_error_report {
 	struct super_block *sb;
 };
 
+struct file_range {
+	const struct path *path;
+	const loff_t *ppos;
+	size_t count;
+};
+
+static inline const struct path *file_range_path(const struct file_range *range)
+{
+	return range->path;
+}
+
 static inline struct inode *fsnotify_data_inode(const void *data, int data_type)
 {
 	switch (data_type) {
@@ -319,6 +331,8 @@  static inline struct inode *fsnotify_data_inode(const void *data, int data_type)
 		return d_inode(data);
 	case FSNOTIFY_EVENT_PATH:
 		return d_inode(((const struct path *)data)->dentry);
+	case FSNOTIFY_EVENT_FILE_RANGE:
+		return d_inode(file_range_path(data)->dentry);
 	case FSNOTIFY_EVENT_ERROR:
 		return ((struct fs_error_report *)data)->inode;
 	default:
@@ -334,6 +348,8 @@  static inline struct dentry *fsnotify_data_dentry(const void *data, int data_typ
 		return (struct dentry *)data;
 	case FSNOTIFY_EVENT_PATH:
 		return ((const struct path *)data)->dentry;
+	case FSNOTIFY_EVENT_FILE_RANGE:
+		return file_range_path(data)->dentry;
 	default:
 		return NULL;
 	}
@@ -345,6 +361,8 @@  static inline const struct path *fsnotify_data_path(const void *data,
 	switch (data_type) {
 	case FSNOTIFY_EVENT_PATH:
 		return data;
+	case FSNOTIFY_EVENT_FILE_RANGE:
+		return file_range_path(data);
 	default:
 		return NULL;
 	}
@@ -360,6 +378,8 @@  static inline struct super_block *fsnotify_data_sb(const void *data,
 		return ((struct dentry *)data)->d_sb;
 	case FSNOTIFY_EVENT_PATH:
 		return ((const struct path *)data)->dentry->d_sb;
+	case FSNOTIFY_EVENT_FILE_RANGE:
+		return file_range_path(data)->dentry->d_sb;
 	case FSNOTIFY_EVENT_ERROR:
 		return ((struct fs_error_report *) data)->sb;
 	default:
@@ -379,6 +399,18 @@  static inline struct fs_error_report *fsnotify_data_error_report(
 	}
 }
 
+static inline const struct file_range *fsnotify_data_file_range(
+							const void *data,
+							int data_type)
+{
+	switch (data_type) {
+	case FSNOTIFY_EVENT_FILE_RANGE:
+		return (struct file_range *)data;
+	default:
+		return NULL;
+	}
+}
+
 /*
  * Index to merged marks iterator array that correlates to a type of watch.
  * The type of watched object can be deduced from the iterator type, but not