vfs: fix panic in __d_lookup() with high dentry hashtable counts

When the number of dentry cache hash table entries gets too high (2147483648 entries), as happens by default on a 16TB system, use of a signed integer in the dcache_init() initialization loop prevents the dentry_hashtable from getting initialized, causing a panic in __d_lookup(). Fix this in dcache_init() and similar areas. Signed-off-by: Dimitri Sivanich <[email protected]> Acked-by: David S. Miller <[email protected]> Cc: Al Viro <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Al Viro <[email protected]>
goeke · Feb 14, 2012 · 074b851 · 074b851
1 parent 1d6f209
commit 074b851
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Showing 5 changed files with 14 additions and 12 deletions.
diff --git a/fs/dcache.c b/fs/dcache.c
@@ -2968,7 +2968,7 @@ __setup("dhash_entries=", set_dhash_entries);
 
 static void __init dcache_init_early(void)
 {
-	int loop;
+	unsigned int loop;
 
 	/* If hashes are distributed across NUMA nodes, defer
 	 * hash allocation until vmalloc space is available.
@@ -2986,13 +2986,13 @@ static void __init dcache_init_early(void)
 					&d_hash_mask,
 					0);
 
-	for (loop = 0; loop < (1 << d_hash_shift); loop++)
+	for (loop = 0; loop < (1U << d_hash_shift); loop++)
 		INIT_HLIST_BL_HEAD(dentry_hashtable + loop);
 }
 
 static void __init dcache_init(void)
 {
-	int loop;
+	unsigned int loop;
 
 	/* 
 	 * A constructor could be added for stable state like the lists,
@@ -3016,7 +3016,7 @@ static void __init dcache_init(void)
 					&d_hash_mask,
 					0);
 
-	for (loop = 0; loop < (1 << d_hash_shift); loop++)
+	for (loop = 0; loop < (1U << d_hash_shift); loop++)
 		INIT_HLIST_BL_HEAD(dentry_hashtable + loop);
 }
 

diff --git a/fs/inode.c b/fs/inode.c
@@ -1651,7 +1651,7 @@ __setup("ihash_entries=", set_ihash_entries);
  */
 void __init inode_init_early(void)
 {
-	int loop;
+	unsigned int loop;
 
 	/* If hashes are distributed across NUMA nodes, defer
 	 * hash allocation until vmalloc space is available.
@@ -1669,13 +1669,13 @@ void __init inode_init_early(void)
 					&i_hash_mask,
 					0);
 
-	for (loop = 0; loop < (1 << i_hash_shift); loop++)
+	for (loop = 0; loop < (1U << i_hash_shift); loop++)
 		INIT_HLIST_HEAD(&inode_hashtable[loop]);
 }
 
 void __init inode_init(void)
 {
-	int loop;
+	unsigned int loop;
 
 	/* inode slab cache */
 	inode_cachep = kmem_cache_create("inode_cache",
@@ -1699,7 +1699,7 @@ void __init inode_init(void)
 					&i_hash_mask,
 					0);
 
-	for (loop = 0; loop < (1 << i_hash_shift); loop++)
+	for (loop = 0; loop < (1U << i_hash_shift); loop++)
 		INIT_HLIST_HEAD(&inode_hashtable[loop]);
 }
 

diff --git a/kernel/pid.c b/kernel/pid.c
@@ -543,12 +543,12 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns)
  */
 void __init pidhash_init(void)
 {
-	int i, pidhash_size;
+	unsigned int i, pidhash_size;
 
 	pid_hash = alloc_large_system_hash("PID", sizeof(*pid_hash), 0, 18,
 					   HASH_EARLY | HASH_SMALL,
 					   &pidhash_shift, NULL, 4096);
-	pidhash_size = 1 << pidhash_shift;
+	pidhash_size = 1U << pidhash_shift;
 
 	for (i = 0; i < pidhash_size; i++)
 		INIT_HLIST_HEAD(&pid_hash[i]);

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
@@ -5236,6 +5236,7 @@ void *__init alloc_large_system_hash(const char *tablename,
 		max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
 		do_div(max, bucketsize);
 	}
+	max = min(max, 0x80000000ULL);
 
 	if (numentries > max)
 		numentries = max;

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
@@ -3240,7 +3240,8 @@ void __init tcp_init(void)
 {
 	struct sk_buff *skb = NULL;
 	unsigned long limit;
-	int i, max_share, cnt;
+	int max_share, cnt;
+	unsigned int i;
 	unsigned long jiffy = jiffies;
 
 	BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
@@ -3283,7 +3284,7 @@ void __init tcp_init(void)
 					&tcp_hashinfo.bhash_size,
 					NULL,
 					64 * 1024);
-	tcp_hashinfo.bhash_size = 1 << tcp_hashinfo.bhash_size;
+	tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
 	for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
 		spin_lock_init(&tcp_hashinfo.bhash[i].lock);
 		INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);