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inotify: add filter of notify options to reduce overload of system

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Signed-off-by: guohao15 <guohao15@xiaomi.com>
This commit is contained in:
guohao15 2024-05-31 16:30:53 +08:00 committed by Xiang Xiao
parent 8731368e45
commit a69d3d78fe
1 changed files with 61 additions and 4 deletions
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65
fs/notify/inotify.c
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@ -88,10 +88,12 @@ struct inotify_watch_s
struct inotify_global_s
{
mutex_t lock; /* Enforces global exclusive access */
int event_cookie; /* Event cookie */
int watch_cookie; /* Watch cookie */
struct hsearch_data hash; /* Hash table for watch lists */
mutex_t lock; /* Enforces global exclusive access */
int event_cookie; /* Event cookie */
int watch_cookie; /* Watch cookie */
uint32_t read_count; /* Number of read events */
uint32_t write_count; /* Number of write events */
struct hsearch_data hash; /* Hash table for watch lists */
};
/****************************************************************************
@ -145,6 +147,49 @@ static struct inotify_global_s g_inotify =
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: notify_add_count
*
* Description:
* Add the count.
*
****************************************************************************/
static void inotify_add_count(uint32_t mask)
{
g_inotify.read_count += (mask & IN_ACCESS) ? 1 : 0;
g_inotify.write_count += (mask & IN_MODIFY) ? 1 : 0;
}
/****************************************************************************
* Name: inotify_sub_count
*
* Description:
* Reduce the count.
*
****************************************************************************/
static void inotify_sub_count(uint32_t mask)
{
g_inotify.read_count -= (mask & IN_ACCESS) ? 1 : 0;
g_inotify.write_count -= (mask & IN_MODIFY) ? 1 : 0;
}
/****************************************************************************
* Name: notify_check_mask
*
* Description:
* Check if the count is valid.
*
****************************************************************************/
static int notify_check_mask(uint32_t mask)
{
return (((mask & IN_ACCESS) && g_inotify.read_count == 0) ||
((mask & IN_MODIFY) && g_inotify.write_count == 0)) ?
-EBADF : OK;
}
/****************************************************************************
* Name: inotify_alloc_event
*
@ -262,6 +307,7 @@ inotify_remove_watch_no_event(FAR struct inotify_watch_s *watch)
list_delete(&watch->d_node);
list_delete(&watch->l_node);
inotify_sub_count(watch->mask);
kmm_free(watch);
if (list_is_empty(&list->watches))
@ -931,6 +977,14 @@ static inline void notify_queue_filep_event(FAR struct file *filep,
return;
}
nxmutex_lock(&g_inotify.lock);
ret = notify_check_mask(mask);
nxmutex_unlock(&g_inotify.lock);
if (ret < 0)
{
return;
}
pathbuffer = lib_get_pathbuffer();
if (pathbuffer == NULL)
{
@ -1037,6 +1091,7 @@ int inotify_add_watch(int fd, FAR const char *pathname, uint32_t mask)
old = inotify_get_watch_from_list(dev, list);
if (old != NULL)
{
uint32_t tmpmask = old->mask;
if (mask & IN_MASK_CREATE)
{
ret = -EEXIST;
@ -1052,6 +1107,7 @@ int inotify_add_watch(int fd, FAR const char *pathname, uint32_t mask)
}
ret = old->wd;
inotify_add_count(tmpmask ^ old->mask);
}
else
{
@ -1066,6 +1122,7 @@ int inotify_add_watch(int fd, FAR const char *pathname, uint32_t mask)
}
ret = watch->wd;
inotify_add_count(mask);
}
out: