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 <sivanich@sgi.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

5 files changed, 14 insertions, 12 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index 16a53cc2cc02..fe19ac13f75f 100644
--- 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
index fb10d86ffad7..d3ebdbe723d0 100644
--- 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
index ce8e00deaccb..9f08dfabaf13 100644
--- 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
index d2186ecb36f7..a13ded1938f0 100644
--- 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
index 37755ccc0e96..22ef5f9fd2ff 100644
--- 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);