Amir Goldstein <amir73il@xxxxxxxxx> writes:
> On Fri, Oct 15, 2021 at 12:39 AM Gabriel Krisman Bertazi
> <krisman@xxxxxxxxxxxxx> wrote:
>>
>> Error events (FAN_FS_ERROR) against the same file system can be merged
>> by simply iterating the error count. The hash is taken from the fsid,
>> without considering the FH. This means that only the first error object
>> is reported.
>>
>> Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
>> ---
>> fs/notify/fanotify/fanotify.c | 39 ++++++++++++++++++++++++++++++++---
>> fs/notify/fanotify/fanotify.h | 4 +++-
>> 2 files changed, 39 insertions(+), 4 deletions(-)
>>
>> diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
>> index 9b970359570a..7032083df62a 100644
>> --- a/fs/notify/fanotify/fanotify.c
>> +++ b/fs/notify/fanotify/fanotify.c
>> @@ -111,6 +111,16 @@ static bool fanotify_name_event_equal(struct fanotify_name_event *fne1,
>> return fanotify_info_equal(info1, info2);
>> }
>>
>> +static bool fanotify_error_event_equal(struct fanotify_error_event *fee1,
>> + struct fanotify_error_event *fee2)
>> +{
>> + /* Error events against the same file system are always merged. */
>> + if (!fanotify_fsid_equal(&fee1->fsid, &fee2->fsid))
>> + return false;
>> +
>> + return true;
>> +}
>> +
>> static bool fanotify_should_merge(struct fanotify_event *old,
>> struct fanotify_event *new)
>> {
>> @@ -141,6 +151,9 @@ static bool fanotify_should_merge(struct fanotify_event *old,
>> case FANOTIFY_EVENT_TYPE_FID_NAME:
>> return fanotify_name_event_equal(FANOTIFY_NE(old),
>> FANOTIFY_NE(new));
>> + case FANOTIFY_EVENT_TYPE_FS_ERROR:
>> + return fanotify_error_event_equal(FANOTIFY_EE(old),
>> + FANOTIFY_EE(new));
>> default:
>> WARN_ON_ONCE(1);
>> }
>> @@ -148,6 +161,22 @@ static bool fanotify_should_merge(struct fanotify_event *old,
>> return false;
>> }
>>
>> +static void fanotify_merge_error_event(struct fanotify_error_event *dest,
>> + struct fanotify_error_event *origin)
>> +{
>> + dest->err_count++;
>> +}
>> +
>> +static void fanotify_merge_event(struct fanotify_event *dest,
>> + struct fanotify_event *origin)
>> +{
>> + dest->mask |= origin->mask;
>> +
>> + if (origin->type == FANOTIFY_EVENT_TYPE_FS_ERROR)
>> + fanotify_merge_error_event(FANOTIFY_EE(dest),
>> + FANOTIFY_EE(origin));
>> +}
>> +
>> /* Limit event merges to limit CPU overhead per event */
>> #define FANOTIFY_MAX_MERGE_EVENTS 128
>>
>> @@ -175,7 +204,7 @@ static int fanotify_merge(struct fsnotify_group *group,
>> if (++i > FANOTIFY_MAX_MERGE_EVENTS)
>> break;
>> if (fanotify_should_merge(old, new)) {
>> - old->mask |= new->mask;
>> + fanotify_merge_event(old, new);
>> return 1;
>> }
>> }
>> @@ -577,7 +606,8 @@ static struct fanotify_event *fanotify_alloc_name_event(struct inode *id,
>> static struct fanotify_event *fanotify_alloc_error_event(
>> struct fsnotify_group *group,
>> __kernel_fsid_t *fsid,
>> - const void *data, int data_type)
>> + const void *data, int data_type,
>> + unsigned int *hash)
>> {
>> struct fs_error_report *report =
>> fsnotify_data_error_report(data, data_type);
>> @@ -591,6 +621,9 @@ static struct fanotify_event *fanotify_alloc_error_event(
>> return NULL;
>>
>> fee->fae.type = FANOTIFY_EVENT_TYPE_FS_ERROR;
>> + fee->err_count = 1;
>> +
>> + *hash ^= fanotify_hash_fsid(fsid);
>>
>> return &fee->fae;
>> }
>
> Forgot to store fee->fsid?
Not really. this is part of the FID info record support, which is done
in patch 23.
--
Gabriel Krisman Bertazi
