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Diffstat (limited to 'fs/notify/fanotify/fanotify.h')
-rw-r--r--fs/notify/fanotify/fanotify.h116
1 files changed, 102 insertions, 14 deletions
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index ea05b8a401e7..68b30504284c 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -2,26 +2,112 @@
#include <linux/fsnotify_backend.h>
#include <linux/path.h>
#include <linux/slab.h>
+#include <linux/exportfs.h>
extern struct kmem_cache *fanotify_mark_cache;
extern struct kmem_cache *fanotify_event_cachep;
extern struct kmem_cache *fanotify_perm_event_cachep;
+/* Possible states of the permission event */
+enum {
+ FAN_EVENT_INIT,
+ FAN_EVENT_REPORTED,
+ FAN_EVENT_ANSWERED,
+ FAN_EVENT_CANCELED,
+};
+
+/*
+ * 3 dwords are sufficient for most local fs (64bit ino, 32bit generation).
+ * For 32bit arch, fid increases the size of fanotify_event by 12 bytes and
+ * fh_* fields increase the size of fanotify_event by another 4 bytes.
+ * For 64bit arch, fid increases the size of fanotify_fid by 8 bytes and
+ * fh_* fields are packed in a hole after mask.
+ */
+#if BITS_PER_LONG == 32
+#define FANOTIFY_INLINE_FH_LEN (3 << 2)
+#else
+#define FANOTIFY_INLINE_FH_LEN (4 << 2)
+#endif
+
+struct fanotify_fid {
+ __kernel_fsid_t fsid;
+ union {
+ unsigned char fh[FANOTIFY_INLINE_FH_LEN];
+ unsigned char *ext_fh;
+ };
+};
+
+static inline void *fanotify_fid_fh(struct fanotify_fid *fid,
+ unsigned int fh_len)
+{
+ return fh_len <= FANOTIFY_INLINE_FH_LEN ? fid->fh : fid->ext_fh;
+}
+
+static inline bool fanotify_fid_equal(struct fanotify_fid *fid1,
+ struct fanotify_fid *fid2,
+ unsigned int fh_len)
+{
+ return fid1->fsid.val[0] == fid2->fsid.val[0] &&
+ fid1->fsid.val[1] == fid2->fsid.val[1] &&
+ !memcmp(fanotify_fid_fh(fid1, fh_len),
+ fanotify_fid_fh(fid2, fh_len), fh_len);
+}
+
/*
* Structure for normal fanotify events. It gets allocated in
* fanotify_handle_event() and freed when the information is retrieved by
* userspace
*/
-struct fanotify_event_info {
+struct fanotify_event {
struct fsnotify_event fse;
+ u32 mask;
/*
- * We hold ref to this path so it may be dereferenced at any point
- * during this object's lifetime
+ * Those fields are outside fanotify_fid to pack fanotify_event nicely
+ * on 64bit arch and to use fh_type as an indication of whether path
+ * or fid are used in the union:
+ * FILEID_ROOT (0) for path, > 0 for fid, FILEID_INVALID for neither.
*/
- struct path path;
+ u8 fh_type;
+ u8 fh_len;
+ u16 pad;
+ union {
+ /*
+ * We hold ref to this path so it may be dereferenced at any
+ * point during this object's lifetime
+ */
+ struct path path;
+ /*
+ * With FAN_REPORT_FID, we do not hold any reference on the
+ * victim object. Instead we store its NFS file handle and its
+ * filesystem's fsid as a unique identifier.
+ */
+ struct fanotify_fid fid;
+ };
struct pid *pid;
};
+static inline bool fanotify_event_has_path(struct fanotify_event *event)
+{
+ return event->fh_type == FILEID_ROOT;
+}
+
+static inline bool fanotify_event_has_fid(struct fanotify_event *event)
+{
+ return event->fh_type != FILEID_ROOT &&
+ event->fh_type != FILEID_INVALID;
+}
+
+static inline bool fanotify_event_has_ext_fh(struct fanotify_event *event)
+{
+ return fanotify_event_has_fid(event) &&
+ event->fh_len > FANOTIFY_INLINE_FH_LEN;
+}
+
+static inline void *fanotify_event_fh(struct fanotify_event *event)
+{
+ return fanotify_fid_fh(&event->fid, event->fh_len);
+}
+
/*
* Structure for permission fanotify events. It gets allocated and freed in
* fanotify_handle_event() since we wait there for user response. When the
@@ -29,16 +115,17 @@ struct fanotify_event_info {
* group->notification_list to group->fanotify_data.access_list to wait for
* user response.
*/
-struct fanotify_perm_event_info {
- struct fanotify_event_info fae;
- int response; /* userspace answer to question */
+struct fanotify_perm_event {
+ struct fanotify_event fae;
+ unsigned short response; /* userspace answer to the event */
+ unsigned short state; /* state of the event */
int fd; /* fd we passed to userspace for this event */
};
-static inline struct fanotify_perm_event_info *
+static inline struct fanotify_perm_event *
FANOTIFY_PE(struct fsnotify_event *fse)
{
- return container_of(fse, struct fanotify_perm_event_info, fae.fse);
+ return container_of(fse, struct fanotify_perm_event, fae.fse);
}
static inline bool fanotify_is_perm_event(u32 mask)
@@ -47,11 +134,12 @@ static inline bool fanotify_is_perm_event(u32 mask)
mask & FANOTIFY_PERM_EVENTS;
}
-static inline struct fanotify_event_info *FANOTIFY_E(struct fsnotify_event *fse)
+static inline struct fanotify_event *FANOTIFY_E(struct fsnotify_event *fse)
{
- return container_of(fse, struct fanotify_event_info, fse);
+ return container_of(fse, struct fanotify_event, fse);
}
-struct fanotify_event_info *fanotify_alloc_event(struct fsnotify_group *group,
- struct inode *inode, u32 mask,
- const struct path *path);
+struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
+ struct inode *inode, u32 mask,
+ const void *data, int data_type,
+ __kernel_fsid_t *fsid);