Merge branch 'ida-4.19' of git://git.infradead.org/users/willy/linux-dax

Pull IDA updates from Matthew Wilcox:
 "A better IDA API:

      id = ida_alloc(ida, GFP_xxx);
      ida_free(ida, id);

  rather than the cumbersome ida_simple_get(), ida_simple_remove().

  The new IDA API is similar to ida_simple_get() but better named.  The
  internal restructuring of the IDA code removes the bitmap
  preallocation nonsense.

  I hope the net -200 lines of code is convincing"

* 'ida-4.19' of git://git.infradead.org/users/willy/linux-dax: (29 commits)
  ida: Change ida_get_new_above to return the id
  ida: Remove old API
  test_ida: check_ida_destroy and check_ida_alloc
  test_ida: Convert check_ida_conv to new API
  test_ida: Move ida_check_max
  test_ida: Move ida_check_leaf
  idr-test: Convert ida_check_nomem to new API
  ida: Start new test_ida module
  target/iscsi: Allocate session IDs from an IDA
  iscsi target: fix session creation failure handling
  drm/vmwgfx: Convert to new IDA API
  dmaengine: Convert to new IDA API
  ppc: Convert vas ID allocation to new IDA API
  media: Convert entity ID allocation to new IDA API
  ppc: Convert mmu context allocation to new IDA API
  Convert net_namespace to new IDA API
  cb710: Convert to new IDA API
  rsxx: Convert to new IDA API
  osd: Convert to new IDA API
  sd: Convert to new IDA API
  ...

1 files changed, 12 insertions, 38 deletions

diff --git a/fs/namespace.c b/fs/namespace.c
index 725d6935fab9f..99186556f8d34 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -61,9 +61,6 @@ __setup("mphash_entries=", set_mphash_entries);
 static u64 event;
 static DEFINE_IDA(mnt_id_ida);
 static DEFINE_IDA(mnt_group_ida);
-static DEFINE_SPINLOCK(mnt_id_lock);
-static int mnt_id_start = 0;
-static int mnt_group_start = 1;
 
 static struct hlist_head *mount_hashtable __read_mostly;
 static struct hlist_head *mountpoint_hashtable __read_mostly;
@@ -101,50 +98,30 @@ static inline struct hlist_head *mp_hash(struct dentry *dentry)
 
 static int mnt_alloc_id(struct mount *mnt)
 {
-	int res;
+	int res = ida_alloc(&mnt_id_ida, GFP_KERNEL);
 
-retry:
-	ida_pre_get(&mnt_id_ida, GFP_KERNEL);
-	spin_lock(&mnt_id_lock);
-	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(&mnt_id_lock);
-	if (res == -EAGAIN)
-		goto retry;
-
-	return res;
+	if (res < 0)
+		return res;
+	mnt->mnt_id = res;
+	return 0;
 }
 
 static void mnt_free_id(struct mount *mnt)
 {
-	int id = mnt->mnt_id;
-	spin_lock(&mnt_id_lock);
-	ida_remove(&mnt_id_ida, id);
-	if (mnt_id_start > id)
-		mnt_id_start = id;
-	spin_unlock(&mnt_id_lock);
+	ida_free(&mnt_id_ida, mnt->mnt_id);
 }
 
 /*
  * Allocate a new peer group ID
- *
- * mnt_group_ida is protected by namespace_sem
  */
 static int mnt_alloc_group_id(struct mount *mnt)
 {
-	int res;
+	int res = ida_alloc_min(&mnt_group_ida, 1, GFP_KERNEL);
 
-	if (!ida_pre_get(&mnt_group_ida, GFP_KERNEL))
-		return -ENOMEM;
-
-	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;
+	if (res < 0)
+		return res;
+	mnt->mnt_group_id = res;
+	return 0;
 }
 
 /*
@@ -152,10 +129,7 @@ static int mnt_alloc_group_id(struct mount *mnt)
  */
 void mnt_release_group_id(struct mount *mnt)
 {
-	int id = mnt->mnt_group_id;
-	ida_remove(&mnt_group_ida, id);
-	if (mnt_group_start > id)
-		mnt_group_start = id;
+	ida_free(&mnt_group_ida, mnt->mnt_group_id);
 	mnt->mnt_group_id = 0;
 }