From f21f62208a6f60e2e05440b2e438d9541822dc4d Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 24 Jun 2009 03:12:00 -0400
Subject: [PATCH] ... and the same for vfsmount id/mount group id
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/namespace.c | 26 ++++++++++++++++++++++----
fs/super.c | 6 ++++--
2 files changed, 26 insertions(+), 6 deletions(-)
diff --git a/fs/namespace.c b/fs/namespace.c
index 4a86b85951645..3dc283fd4716b 100644
--- 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 808ffd59e01bc..2761d3e22ed92 100644
--- 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;
}
--
2.30.2