1 files changed, 42 insertions, 25 deletions

diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 6e8724958116..2cf3b74391ca 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -54,6 +54,7 @@ static void proc_evict_inode(struct inode *inode)
 }
 
 static struct kmem_cache *proc_inode_cachep __ro_after_init;
+static struct kmem_cache *pde_opener_cache __ro_after_init;
 
 static struct inode *proc_alloc_inode(struct super_block *sb)
 {
@@ -92,7 +93,7 @@ static void init_once(void *foo)
 	inode_init_once(&ei->vfs_inode);
 }
 
-void __init proc_init_inodecache(void)
+void __init proc_init_kmemcache(void)
 {
 	proc_inode_cachep = kmem_cache_create("proc_inode_cache",
 					     sizeof(struct proc_inode),
@@ -100,6 +101,13 @@ void __init proc_init_inodecache(void)
 						SLAB_MEM_SPREAD|SLAB_ACCOUNT|
 						SLAB_PANIC),
 					     init_once);
+	pde_opener_cache =
+		kmem_cache_create("pde_opener", sizeof(struct pde_opener), 0,
+				  SLAB_ACCOUNT|SLAB_PANIC, NULL);
+	proc_dir_entry_cache = kmem_cache_create_usercopy(
+		"proc_dir_entry", sizeof(struct proc_dir_entry), 0, SLAB_PANIC,
+		offsetof(struct proc_dir_entry, inline_name),
+		sizeof_field(struct proc_dir_entry, inline_name), NULL);
 }
 
 static int proc_show_options(struct seq_file *seq, struct dentry *root)
@@ -138,7 +146,7 @@ static void unuse_pde(struct proc_dir_entry *pde)
 		complete(pde->pde_unload_completion);
 }
 
-/* pde is locked */
+/* pde is locked on entry, unlocked on exit */
 static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo)
 {
 	/*
@@ -157,9 +165,10 @@ static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo)
 		pdeo->c = &c;
 		spin_unlock(&pde->pde_unload_lock);
 		wait_for_completion(&c);
-		spin_lock(&pde->pde_unload_lock);
 	} else {
 		struct file *file;
+		struct completion *c;
+
 		pdeo->closing = true;
 		spin_unlock(&pde->pde_unload_lock);
 		file = pdeo->file;
@@ -167,9 +176,11 @@ static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo)
 		spin_lock(&pde->pde_unload_lock);
 		/* After ->release. */
 		list_del(&pdeo->lh);
-		if (unlikely(pdeo->c))
-			complete(pdeo->c);
-		kfree(pdeo);
+		c = pdeo->c;
+		spin_unlock(&pde->pde_unload_lock);
+		if (unlikely(c))
+			complete(c);
+		kmem_cache_free(pde_opener_cache, pdeo);
 	}
 }
 
@@ -188,6 +199,7 @@ void proc_entry_rundown(struct proc_dir_entry *de)
 		struct pde_opener *pdeo;
 		pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh);
 		close_pdeo(de, pdeo);
+		spin_lock(&de->pde_unload_lock);
 	}
 	spin_unlock(&de->pde_unload_lock);
 }
@@ -338,31 +350,36 @@ static int proc_reg_open(struct inode *inode, struct file *file)
 	 *
 	 * Save every "struct file" with custom ->release hook.
 	 */
-	pdeo = kmalloc(sizeof(struct pde_opener), GFP_KERNEL);
-	if (!pdeo)
-		return -ENOMEM;
-
-	if (!use_pde(pde)) {
-		kfree(pdeo);
+	if (!use_pde(pde))
 		return -ENOENT;
-	}
-	open = pde->proc_fops->open;
+
 	release = pde->proc_fops->release;
+	if (release) {
+		pdeo = kmem_cache_alloc(pde_opener_cache, GFP_KERNEL);
+		if (!pdeo) {
+			rv = -ENOMEM;
+			goto out_unuse;
+		}
+	}
 
+	open = pde->proc_fops->open;
 	if (open)
 		rv = open(inode, file);
 
-	if (rv == 0 && release) {
-		/* To know what to release. */
-		pdeo->file = file;
-		pdeo->closing = false;
-		pdeo->c = NULL;
-		spin_lock(&pde->pde_unload_lock);
-		list_add(&pdeo->lh, &pde->pde_openers);
-		spin_unlock(&pde->pde_unload_lock);
-	} else
-		kfree(pdeo);
+	if (release) {
+		if (rv == 0) {
+			/* To know what to release. */
+			pdeo->file = file;
+			pdeo->closing = false;
+			pdeo->c = NULL;
+			spin_lock(&pde->pde_unload_lock);
+			list_add(&pdeo->lh, &pde->pde_openers);
+			spin_unlock(&pde->pde_unload_lock);
+		} else
+			kmem_cache_free(pde_opener_cache, pdeo);
+	}
 
+out_unuse:
 	unuse_pde(pde);
 	return rv;
 }
@@ -375,7 +392,7 @@ static int proc_reg_release(struct inode *inode, struct file *file)
 	list_for_each_entry(pdeo, &pde->pde_openers, lh) {
 		if (pdeo->file == file) {
 			close_pdeo(pde, pdeo);
-			break;
+			return 0;
 		}
 	}
 	spin_unlock(&pde->pde_unload_lock);