@@ -10,6 +10,9 @@ extern struct kmem_cache *fanotify_perm_event_cachep;
/* The size of the variable length buffer storing fsid and file handle */
#define FANOTIFY_FID_LEN(handle_bytes) \
(sizeof(struct fanotify_event_fid) + (handle_bytes))
+#define FANOTIFY_FID_INFO_LEN(event) \
+ (sizeof(struct fanotify_event_info) + \
+ FANOTIFY_FID_LEN((event)->info.fid->handle_bytes))
struct fanotify_info {
struct fanotify_event_fid *fid;
@@ -47,6 +47,16 @@ struct kmem_cache *fanotify_mark_cache __read_mostly;
struct kmem_cache *fanotify_event_cachep __read_mostly;
struct kmem_cache *fanotify_perm_event_cachep __read_mostly;
+static int round_event_fid_len(struct fsnotify_event *fsn_event)
+{
+ struct fanotify_event *event = FANOTIFY_E(fsn_event);
+
+ if (!FANOTIFY_HAS_FID(event))
+ return 0;
+
+ return roundup(FANOTIFY_FID_INFO_LEN(event), FAN_EVENT_METADATA_LEN);
+}
+
/*
* Get an fsnotify notification event if one exists and is small
* enough to fit in "count". Return an error pointer if the count
@@ -57,6 +67,9 @@ struct kmem_cache *fanotify_perm_event_cachep __read_mostly;
static struct fsnotify_event *get_one_event(struct fsnotify_group *group,
size_t count)
{
+ size_t event_size = FAN_EVENT_METADATA_LEN;
+ struct fsnotify_event *event;
+
assert_spin_locked(&group->notification_lock);
pr_debug("%s: group=%p count=%zd\n", __func__, group, count);
@@ -64,11 +77,18 @@ static struct fsnotify_event *get_one_event(struct fsnotify_group *group,
if (fsnotify_notify_queue_is_empty(group))
return NULL;
- if (FAN_EVENT_METADATA_LEN > count)
+ if (FAN_GROUP_FLAG(group, FAN_REPORT_FID)) {
+ event = fsnotify_peek_first_event(group);
+ event_size += round_event_fid_len(event);
+ }
+
+ if (event_size > count)
return ERR_PTR(-EINVAL);
- /* held the notification_lock the whole time, so this is the
- * same event we peeked above */
+ /*
+ * Held the notification_lock the whole time, so this is the
+ * same event we peeked above
+ */
return fsnotify_remove_first_event(group);
}
@@ -129,7 +149,7 @@ static int fill_event_metadata(struct fsnotify_group *group,
group, metadata, fsn_event);
*file = NULL;
- event = container_of(fsn_event, struct fanotify_event, fse);
+ event = FANOTIFY_E(fsn_event);
metadata->event_len = FAN_EVENT_METADATA_LEN;
metadata->metadata_len = FAN_EVENT_METADATA_LEN;
metadata->vers = FANOTIFY_METADATA_VERSION;
@@ -139,6 +159,7 @@ static int fill_event_metadata(struct fsnotify_group *group,
if (FAN_GROUP_FLAG(group, FAN_REPORT_FID) ||
unlikely(fsn_event->mask & FAN_Q_OVERFLOW)) {
metadata->fd = FAN_NOFD;
+ metadata->event_len += round_event_fid_len(fsn_event);
} else {
metadata->fd = create_fd(group, event, file);
if (metadata->fd < 0)
@@ -208,6 +229,38 @@ static int process_access_response(struct fsnotify_group *group,
return 0;
}
+static int copy_fid_to_user(struct fsnotify_event *fsn_event, char __user *buf)
+{
+ struct fanotify_event *event = FANOTIFY_E(fsn_event);
+ struct fanotify_event_info ei;
+ size_t fid_len;
+ size_t pad_len = round_event_fid_len(fsn_event);
+
+ if (!pad_len)
+ return 0;
+
+ /* Copy event info header followed by fid buffer */
+ fid_len = FANOTIFY_FID_INFO_LEN(event);
+ pad_len -= fid_len;
+ ei.info_type = FAN_EVENT_INFO_TYPE_FID;
+ ei.reserved = 0;
+ ei.info_len = fid_len;
+ if (copy_to_user(buf, &ei, sizeof(ei)))
+ return -EFAULT;
+
+ buf += sizeof(ei);
+ fid_len -= sizeof(ei);
+ if (copy_to_user(buf, event->info.fid, fid_len))
+ return -EFAULT;
+
+ /* Pad with 0's */
+ buf += fid_len;
+ if (pad_len && clear_user(buf, pad_len))
+ return -EFAULT;
+
+ return 0;
+}
+
static ssize_t copy_event_to_user(struct fsnotify_group *group,
struct fsnotify_event *event,
char __user *buf)
@@ -224,15 +277,20 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
fd = fanotify_event_metadata.fd;
ret = -EFAULT;
- if (copy_to_user(buf, &fanotify_event_metadata,
- fanotify_event_metadata.event_len))
+ if (copy_to_user(buf, &fanotify_event_metadata, FAN_EVENT_METADATA_LEN))
goto out_close_fd;
if (fanotify_is_perm_event(event->mask))
FANOTIFY_PE(event)->fd = fd;
- if (fd != FAN_NOFD)
+ if (fd != FAN_NOFD) {
fd_install(fd, f);
+ } else if (FAN_GROUP_FLAG(group, FAN_REPORT_FID)) {
+ ret = copy_fid_to_user(event, buf + FAN_EVENT_METADATA_LEN);
+ if (ret < 0)
+ return ret;
+ }
+
return fanotify_event_metadata.event_len;
out_close_fd:
If group requested FAN_REPORT_FID and event has file identifier copy that information to user reading the event after reading event metadata. metadata->event_len includes the length of the fid information. Signed-off-by: Amir Goldstein <amir73il@gmail.com> --- fs/notify/fanotify/fanotify.h | 3 ++ fs/notify/fanotify/fanotify_user.c | 72 +++++++++++++++++++++++++++--- 2 files changed, 68 insertions(+), 7 deletions(-)