fsnotify: replace inode pointer with an object id

The event inode field is used only for comparison in queue merges and
cannot be dereferenced after handle_event(), because it does not hold a
refcount on the inode.

Replace it with an abstract id to do the same thing.

Link: https://lore.kernel.org/r/20200319151022.31456-8-amir73il@gmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Amir Goldstein 2020-03-19 17:10:15 +02:00 committed by Jan Kara
parent 017de65fe5
commit dfc2d2594e
4 changed files with 8 additions and 9 deletions

View File

@ -26,7 +26,7 @@ static bool should_merge(struct fsnotify_event *old_fsn,
old = FANOTIFY_E(old_fsn);
new = FANOTIFY_E(new_fsn);
if (old_fsn->inode != new_fsn->inode || old->pid != new->pid ||
if (old_fsn->objectid != new_fsn->objectid || old->pid != new->pid ||
old->fh_type != new->fh_type || old->fh_len != new->fh_len)
return false;
@ -312,7 +312,7 @@ struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
if (!event)
goto out;
init: __maybe_unused
fsnotify_init_event(&event->fse, inode);
fsnotify_init_event(&event->fse, (unsigned long)inode);
event->mask = mask;
if (FAN_GROUP_FLAG(group, FAN_REPORT_TID))
event->pid = get_pid(task_pid(current));

View File

@ -39,7 +39,7 @@ static bool event_compare(struct fsnotify_event *old_fsn,
if (old->mask & FS_IN_IGNORED)
return false;
if ((old->mask == new->mask) &&
(old_fsn->inode == new_fsn->inode) &&
(old_fsn->objectid == new_fsn->objectid) &&
(old->name_len == new->name_len) &&
(!old->name_len || !strcmp(old->name, new->name)))
return true;
@ -116,7 +116,7 @@ int inotify_handle_event(struct fsnotify_group *group,
mask &= ~IN_ISDIR;
fsn_event = &event->fse;
fsnotify_init_event(fsn_event, inode);
fsnotify_init_event(fsn_event, (unsigned long)inode);
event->mask = mask;
event->wd = i_mark->wd;
event->sync_cookie = cookie;

View File

@ -635,7 +635,7 @@ static struct fsnotify_group *inotify_new_group(unsigned int max_events)
return ERR_PTR(-ENOMEM);
}
group->overflow_event = &oevent->fse;
fsnotify_init_event(group->overflow_event, NULL);
fsnotify_init_event(group->overflow_event, 0);
oevent->mask = FS_Q_OVERFLOW;
oevent->wd = -1;
oevent->sync_cookie = 0;

View File

@ -132,8 +132,7 @@ struct fsnotify_ops {
*/
struct fsnotify_event {
struct list_head list;
/* inode may ONLY be dereferenced during handle_event(). */
struct inode *inode; /* either the inode the event happened to or its parent */
unsigned long objectid; /* identifier for queue merges */
};
/*
@ -526,10 +525,10 @@ extern void fsnotify_finish_user_wait(struct fsnotify_iter_info *iter_info);
extern bool fsnotify_prepare_user_wait(struct fsnotify_iter_info *iter_info);
static inline void fsnotify_init_event(struct fsnotify_event *event,
struct inode *inode)
unsigned long objectid)
{
INIT_LIST_HEAD(&event->list);
event->inode = inode;
event->objectid = objectid;
}
#else