... and the same for vfsmount id/mount group id

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/namespace.c b/fs/namespace.c
index 4a86b85951645ffe2d23b7f00ecf5919725eec78..3dc283fd4716beacfe037839d2fc5fd5974c925d 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -42,6 +42,8 @@ __cacheline_aligned_in_smp DEFINE_SPINLOCK(vfsmount_lock);
 static int event;
 static DEFINE_IDA(mnt_id_ida);
 static DEFINE_IDA(mnt_group_ida);
+static int mnt_id_start = 0;
+static int mnt_group_start = 1;
 
 static struct list_head *mount_hashtable __read_mostly;
 static struct kmem_cache *mnt_cache __read_mostly;
@@ -69,7 +71,9 @@ static int mnt_alloc_id(struct vfsmount *mnt)
 retry:
        ida_pre_get(&mnt_id_ida, GFP_KERNEL);
        spin_lock(&vfsmount_lock);
-       res = ida_get_new(&mnt_id_ida, &mnt->mnt_id);
+       res = ida_get_new_above(&mnt_id_ida, mnt_id_start, &mnt->mnt_id);
+       if (!res)
+               mnt_id_start = mnt->mnt_id + 1;
        spin_unlock(&vfsmount_lock);
        if (res == -EAGAIN)
                goto retry;
@@ -79,8 +83,11 @@ retry:
 
 static void mnt_free_id(struct vfsmount *mnt)
 {
+       int id = mnt->mnt_id;
        spin_lock(&vfsmount_lock);
-       ida_remove(&mnt_id_ida, mnt->mnt_id);
+       ida_remove(&mnt_id_ida, id);
+       if (mnt_id_start > id)
+               mnt_id_start = id;
        spin_unlock(&vfsmount_lock);
 }
 
@@ -91,10 +98,18 @@ static void mnt_free_id(struct vfsmount *mnt)
  */
 static int mnt_alloc_group_id(struct vfsmount *mnt)
 {
+       int res;
+
        if (!ida_pre_get(&mnt_group_ida, GFP_KERNEL))
                return -ENOMEM;
 
-       return ida_get_new_above(&mnt_group_ida, 1, &mnt->mnt_group_id);
+       res = ida_get_new_above(&mnt_group_ida,
+                               mnt_group_start,
+                               &mnt->mnt_group_id);
+       if (!res)
+               mnt_group_start = mnt->mnt_group_id + 1;
+
+       return res;
 }
 
 /*
@@ -102,7 +117,10 @@ static int mnt_alloc_group_id(struct vfsmount *mnt)
  */
 void mnt_release_group_id(struct vfsmount *mnt)
 {
-       ida_remove(&mnt_group_ida, mnt->mnt_group_id);
+       int id = mnt->mnt_group_id;
+       ida_remove(&mnt_group_ida, id);
+       if (mnt_group_start > id)
+               mnt_group_start = id;
        mnt->mnt_group_id = 0;
 }
 

diff --git a/fs/super.c b/fs/super.c
index 808ffd59e01bc3262cb0c080808cefd09fb1dc95..2761d3e22ed92321f204a34f8de08491db6f3083 100644 (file)
--- a/fs/super.c
+++ b/fs/super.c
@@ -620,7 +620,8 @@ int set_anon_super(struct super_block *s, void *data)
                return -ENOMEM;
        spin_lock(&unnamed_dev_lock);
        error = ida_get_new_above(&unnamed_dev_ida, unnamed_dev_start, &dev);
-       unnamed_dev_start = dev + 1;
+       if (!error)
+               unnamed_dev_start = dev + 1;
        spin_unlock(&unnamed_dev_lock);
        if (error == -EAGAIN)
                /* We raced and lost with another CPU. */
@@ -631,7 +632,8 @@ int set_anon_super(struct super_block *s, void *data)
        if ((dev & MAX_ID_MASK) == (1 << MINORBITS)) {
                spin_lock(&unnamed_dev_lock);
                ida_remove(&unnamed_dev_ida, dev);
-               unnamed_dev_start = dev;
+               if (unnamed_dev_start > dev)
+                       unnamed_dev_start = dev;
                spin_unlock(&unnamed_dev_lock);
                return -EMFILE;
        }