Re: [PATCH v3 04/15] fanotify: Split superblock marks out to a new cache

---
Changes since v2:
  - Move mark initialization to fanotify_alloc_mark (Amir)

Changes since v1:
  - Only extend superblock marks (Amir)
---
 fs/notify/fanotify/fanotify.c      | 10 ++++++--
 fs/notify/fanotify/fanotify.h      | 13 ++++++++++
 fs/notify/fanotify/fanotify_user.c | 38 ++++++++++++++++++++++++++++--
 include/linux/fsnotify_backend.h   |  1 +
 4 files changed, 58 insertions(+), 4 deletions(-)

diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 310246f8d3f1..0f760770d4c9 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c

@@ -869,9 +869,15 @@ static void fanotify_freeing_mark(struct fsnotify_mark *mark,
                dec_ucount(group->fanotify_data.ucounts, UCOUNT_FANOTIFY_MARKS);
 }

-static void fanotify_free_mark(struct fsnotify_mark *fsn_mark)
+static void fanotify_free_mark(struct fsnotify_mark *mark)
 {
-       kmem_cache_free(fanotify_mark_cache, fsn_mark);
+       if (mark->flags & FSNOTIFY_MARK_FLAG_SB) {
+               struct fanotify_sb_mark *fa_mark = FANOTIFY_SB_MARK(mark);

+
+               kmem_cache_free(fanotify_sb_mark_cache, fa_mark);
+       } else {
+               kmem_cache_free(fanotify_mark_cache, mark);
+       }
 }

 const struct fsnotify_ops fanotify_fsnotify_ops = {

diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index 4a5e555dc3d2..fd125a949187 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h

@@ -6,6 +6,7 @@
 #include <linux/hashtable.h>

 extern struct kmem_cache *fanotify_mark_cache;
+extern struct kmem_cache *fanotify_sb_mark_cache;
 extern struct kmem_cache *fanotify_fid_event_cachep;
 extern struct kmem_cache *fanotify_path_event_cachep;
 extern struct kmem_cache *fanotify_perm_event_cachep;

@@ -129,6 +130,18 @@ static inline void fanotify_info_copy_name(struct fanotify_info *info,
               name->name);
 }

+struct fanotify_sb_mark {
+       struct fsnotify_mark fsn_mark;
+};
+
+static inline
+struct fanotify_sb_mark *FANOTIFY_SB_MARK(struct fsnotify_mark *mark)
+{
+       WARN_ON(!(mark->flags & FSNOTIFY_MARK_FLAG_SB));
+
+       return container_of(mark, struct fanotify_sb_mark, fsn_mark);
+}
+
 /*
  * Common structure for fanotify events. Concrete structs are allocated in
  * fanotify_handle_event() and freed when the information is retrieved by

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 67b18dfe0025..a42521e140e6 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c

@@ -99,6 +99,7 @@ struct ctl_table fanotify_table[] = {
 extern const struct fsnotify_ops fanotify_fsnotify_ops;

 struct kmem_cache *fanotify_mark_cache __read_mostly;
+struct kmem_cache *fanotify_sb_mark_cache __read_mostly;
 struct kmem_cache *fanotify_fid_event_cachep __read_mostly;
 struct kmem_cache *fanotify_path_event_cachep __read_mostly;
 struct kmem_cache *fanotify_perm_event_cachep __read_mostly;

@@ -915,6 +916,38 @@ static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark,
        return mask & ~oldmask;
 }

+static struct fsnotify_mark *fanotify_alloc_mark(struct fsnotify_group *group,
+                                                unsigned int type)
+{
+       struct fanotify_sb_mark *sb_mark;
+       struct fsnotify_mark *mark;
+
+       switch (type) {
+       case FSNOTIFY_OBJ_TYPE_SB:
+               sb_mark = kmem_cache_zalloc(fanotify_sb_mark_cache, GFP_KERNEL);
+               if (!sb_mark)
+                       return NULL;
+               mark = &sb_mark->fsn_mark;
+               break;
+
+       case FSNOTIFY_OBJ_TYPE_INODE:
+       case FSNOTIFY_OBJ_TYPE_PARENT:
+       case FSNOTIFY_OBJ_TYPE_VFSMOUNT:
+               mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
+               break;
+       default:
+               WARN_ON(1);
+               return NULL;
+       }
+
+       fsnotify_init_mark(mark, group);
+
+       if (type == FSNOTIFY_OBJ_TYPE_SB)
+               mark->flags |= FSNOTIFY_MARK_FLAG_SB;
+
+       return mark;
+}
+
 static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group,
                                                   fsnotify_connp_t *connp,
                                                   unsigned int type,

@@ -933,13 +966,12 @@ static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group,
            !inc_ucount(ucounts->ns, ucounts->uid, UCOUNT_FANOTIFY_MARKS))
                return ERR_PTR(-ENOSPC);

-       mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
+       mark = fanotify_alloc_mark(group, type);
        if (!mark) {
                ret = -ENOMEM;
                goto out_dec_ucounts;
        }

-       fsnotify_init_mark(mark, group);
        ret = fsnotify_add_mark_locked(mark, connp, type, 0, fsid);
        if (ret) {
                fsnotify_put_mark(mark);

@@ -1497,6 +1529,8 @@ static int __init fanotify_user_setup(void)

        fanotify_mark_cache = KMEM_CACHE(fsnotify_mark,
                                         SLAB_PANIC|SLAB_ACCOUNT);
+       fanotify_sb_mark_cache = KMEM_CACHE(fanotify_sb_mark,
+                                           SLAB_PANIC|SLAB_ACCOUNT);
        fanotify_fid_event_cachep = KMEM_CACHE(fanotify_fid_event,
                                               SLAB_PANIC);
        fanotify_path_event_cachep = KMEM_CACHE(fanotify_path_event,

diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 1ce66748a2d2..c4473b467c28 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h

@@ -401,6 +401,7 @@ struct fsnotify_mark {
 #define FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY 0x01
 #define FSNOTIFY_MARK_FLAG_ALIVE               0x02
 #define FSNOTIFY_MARK_FLAG_ATTACHED            0x04
+#define FSNOTIFY_MARK_FLAG_SB                  0x08
        unsigned int flags;             /* flags [mark->lock] */
 };

--

2.32.0