[PATCH] hugetlbfs: move free_inodes accounting

Move hugetlbfs accounting into ->alloc_inode / ->destroy_inode.  This keeps
the code simpler, fixes a loeak where a failing inode allocation wouldn't
decrement the counter and moves hugetlbfs_delete_inode and
hugetlbfs_forget_inode closer to their generic counterparts.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index a826a8add5e30b55bbded97894a34cde027e5fe3..8e9d436333656a23b9aeab9b064f194ddeb10371 100644 (file)
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -224,8 +224,6 @@ static void truncate_hugepages(struct address_space *mapping, loff_t lstart)
 
 static void hugetlbfs_delete_inode(struct inode *inode)
 {
-       struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(inode->i_sb);
-
        hlist_del_init(&inode->i_hash);
        list_del_init(&inode->i_list);
        list_del_init(&inode->i_sb_list);
@@ -238,12 +236,6 @@ static void hugetlbfs_delete_inode(struct inode *inode)
 
        security_inode_delete(inode);
 
-       if (sbinfo->free_inodes >= 0) {
-               spin_lock(&sbinfo->stat_lock);
-               sbinfo->free_inodes++;
-               spin_unlock(&sbinfo->stat_lock);
-       }
-
        clear_inode(inode);
        destroy_inode(inode);
 }
@@ -251,7 +243,6 @@ static void hugetlbfs_delete_inode(struct inode *inode)
 static void hugetlbfs_forget_inode(struct inode *inode)
 {
        struct super_block *super_block = inode->i_sb;
-       struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(super_block);
 
        if (hlist_unhashed(&inode->i_hash))
                goto out_truncate;
@@ -278,12 +269,6 @@ out_truncate:
        if (inode->i_data.nrpages)
                truncate_hugepages(&inode->i_data, 0);
 
-       if (sbinfo->free_inodes >= 0) {
-               spin_lock(&sbinfo->stat_lock);
-               sbinfo->free_inodes++;
-               spin_unlock(&sbinfo->stat_lock);
-       }
-
        clear_inode(inode);
        destroy_inode(inode);
 }
@@ -375,17 +360,6 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid,
                                        gid_t gid, int mode, dev_t dev)
 {
        struct inode *inode;
-       struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
-
-       if (sbinfo->free_inodes >= 0) {
-               spin_lock(&sbinfo->stat_lock);
-               if (!sbinfo->free_inodes) {
-                       spin_unlock(&sbinfo->stat_lock);
-                       return NULL;
-               }
-               sbinfo->free_inodes--;
-               spin_unlock(&sbinfo->stat_lock);
-       }
 
        inode = new_inode(sb);
        if (inode) {
@@ -527,29 +501,51 @@ static void hugetlbfs_put_super(struct super_block *sb)
        }
 }
 
+static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo)
+{
+       if (sbinfo->free_inodes >= 0) {
+               spin_lock(&sbinfo->stat_lock);
+               if (unlikely(!sbinfo->free_inodes)) {
+                       spin_unlock(&sbinfo->stat_lock);
+                       return 0;
+               }
+               sbinfo->free_inodes--;
+               spin_unlock(&sbinfo->stat_lock);
+       }
+
+       return 1;
+}
+
+static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
+{
+       if (sbinfo->free_inodes >= 0) {
+               spin_lock(&sbinfo->stat_lock);
+               sbinfo->free_inodes++;
+               spin_unlock(&sbinfo->stat_lock);
+       }
+}
+
+
 static kmem_cache_t *hugetlbfs_inode_cachep;
 
 static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
 {
+       struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
        struct hugetlbfs_inode_info *p;
 
+       if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
+               return NULL;
        p = kmem_cache_alloc(hugetlbfs_inode_cachep, SLAB_KERNEL);
-       if (!p)
+       if (unlikely(!p)) {
+               hugetlbfs_inc_free_inodes(sbinfo);
                return NULL;
+       }
        return &p->vfs_inode;
 }
 
-static void init_once(void *foo, kmem_cache_t *cachep, unsigned long flags)
-{
-       struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
-
-       if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
-           SLAB_CTOR_CONSTRUCTOR)
-               inode_init_once(&ei->vfs_inode);
-}
-
 static void hugetlbfs_destroy_inode(struct inode *inode)
 {
+       hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
        mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
        kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
 }
@@ -561,6 +557,16 @@ static struct address_space_operations hugetlbfs_aops = {
        .set_page_dirty = hugetlbfs_set_page_dirty,
 };
 
+
+static void init_once(void *foo, kmem_cache_t *cachep, unsigned long flags)
+{
+       struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;
+
+       if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
+           SLAB_CTOR_CONSTRUCTOR)
+               inode_init_once(&ei->vfs_inode);
+}
+
 struct file_operations hugetlbfs_file_operations = {
        .mmap                   = hugetlbfs_file_mmap,
        .fsync                  = simple_sync_file,