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authorGabriel Krisman Bertazi <krisman@collabora.com>2021-10-25 21:27:34 +0200
committerJan Kara <jack@suse.cz>2021-10-27 12:35:05 +0200
commit734a1a5eccc5f7473002b0669f788e135f1f64aa (patch)
tree9a2bf10a36c11cd378181c3cefba5440391715a5 /fs/notify
parentfanotify: Reserve UAPI bits for FAN_FS_ERROR (diff)
downloadlinux-734a1a5eccc5f7473002b0669f788e135f1f64aa.tar.xz
linux-734a1a5eccc5f7473002b0669f788e135f1f64aa.zip
fanotify: Pre-allocate pool of error events
Pre-allocate slots for file system errors to have greater chances of succeeding, since error events can happen in GFP_NOFS context. This patch introduces a group-wide mempool of error events, shared by all FAN_FS_ERROR marks in this group. Link: https://lore.kernel.org/r/20211025192746.66445-20-krisman@collabora.com Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/notify')
-rw-r--r--fs/notify/fanotify/fanotify.c3
-rw-r--r--fs/notify/fanotify/fanotify.h11
-rw-r--r--fs/notify/fanotify/fanotify_user.c26
3 files changed, 39 insertions, 1 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 8f152445d75c..01d68dfc74aa 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -819,6 +819,9 @@ static void fanotify_free_group_priv(struct fsnotify_group *group)
if (group->fanotify_data.ucounts)
dec_ucount(group->fanotify_data.ucounts,
UCOUNT_FANOTIFY_GROUPS);
+
+ if (mempool_initialized(&group->fanotify_data.error_events_pool))
+ mempool_exit(&group->fanotify_data.error_events_pool);
}
static void fanotify_free_path_event(struct fanotify_event *event)
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index c42cf8fd7d79..a577e87fac2b 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -141,6 +141,7 @@ enum fanotify_event_type {
FANOTIFY_EVENT_TYPE_PATH,
FANOTIFY_EVENT_TYPE_PATH_PERM,
FANOTIFY_EVENT_TYPE_OVERFLOW, /* struct fanotify_event */
+ FANOTIFY_EVENT_TYPE_FS_ERROR, /* struct fanotify_error_event */
__FANOTIFY_EVENT_TYPE_NUM
};
@@ -196,6 +197,16 @@ FANOTIFY_NE(struct fanotify_event *event)
return container_of(event, struct fanotify_name_event, fae);
}
+struct fanotify_error_event {
+ struct fanotify_event fae;
+};
+
+static inline struct fanotify_error_event *
+FANOTIFY_EE(struct fanotify_event *event)
+{
+ return container_of(event, struct fanotify_error_event, fae);
+}
+
static inline __kernel_fsid_t *fanotify_event_fsid(struct fanotify_event *event)
{
if (event->type == FANOTIFY_EVENT_TYPE_FID)
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 66ee3c2805c7..2f4182b754b2 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -30,6 +30,7 @@
#define FANOTIFY_DEFAULT_MAX_EVENTS 16384
#define FANOTIFY_OLD_DEFAULT_MAX_MARKS 8192
#define FANOTIFY_DEFAULT_MAX_GROUPS 128
+#define FANOTIFY_DEFAULT_FEE_POOL_SIZE 32
/*
* Legacy fanotify marks limits (8192) is per group and we introduced a tunable
@@ -1054,6 +1055,15 @@ out_dec_ucounts:
return ERR_PTR(ret);
}
+static int fanotify_group_init_error_pool(struct fsnotify_group *group)
+{
+ if (mempool_initialized(&group->fanotify_data.error_events_pool))
+ return 0;
+
+ return mempool_init_kmalloc_pool(&group->fanotify_data.error_events_pool,
+ FANOTIFY_DEFAULT_FEE_POOL_SIZE,
+ sizeof(struct fanotify_error_event));
+}
static int fanotify_add_mark(struct fsnotify_group *group,
fsnotify_connp_t *connp, unsigned int type,
@@ -1062,6 +1072,7 @@ static int fanotify_add_mark(struct fsnotify_group *group,
{
struct fsnotify_mark *fsn_mark;
__u32 added;
+ int ret = 0;
mutex_lock(&group->mark_mutex);
fsn_mark = fsnotify_find_mark(connp, group);
@@ -1072,13 +1083,26 @@ static int fanotify_add_mark(struct fsnotify_group *group,
return PTR_ERR(fsn_mark);
}
}
+
+ /*
+ * Error events are pre-allocated per group, only if strictly
+ * needed (i.e. FAN_FS_ERROR was requested).
+ */
+ if (!(flags & FAN_MARK_IGNORED_MASK) && (mask & FAN_FS_ERROR)) {
+ ret = fanotify_group_init_error_pool(group);
+ if (ret)
+ goto out;
+ }
+
added = fanotify_mark_add_to_mask(fsn_mark, mask, flags);
if (added & ~fsnotify_conn_mask(fsn_mark->connector))
fsnotify_recalc_mask(fsn_mark->connector);
+
+out:
mutex_unlock(&group->mark_mutex);
fsnotify_put_mark(fsn_mark);
- return 0;
+ return ret;
}
static int fanotify_add_vfsmount_mark(struct fsnotify_group *group,