Merge patch series "vfs: follow-on fixes for i_ino widening"

Jeff Layton <jlayton@kernel.org> says:

Just some patches to fix follow-on issues reported after the
inode->i_ino widening series.

* patches from https://patch.msgid.link/20260316-iino-u64-v3-0-d1076b8f7a20@kernel.org:
  nilfs2: fix 64-bit division operations in nilfs_bmap_find_target_in_group()
  EVM: add comment describing why ino field is still unsigned long

Link: https://patch.msgid.link/20260316-iino-u64-v3-0-d1076b8f7a20@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

2 files changed, 17 insertions, 4 deletions

diff --git a/fs/nilfs2/bmap.c b/fs/nilfs2/bmap.c
index 824f2bd91c16..5f0f1f283af0 100644
--- a/fs/nilfs2/bmap.c
+++ b/fs/nilfs2/bmap.c
@@ -450,18 +450,25 @@ __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *bmap, __u64 key)
 		return NILFS_BMAP_INVALID_PTR;
 }
 
-#define NILFS_BMAP_GROUP_DIV	8
+#define NILFS_BMAP_GROUP_DIV	8	/* must be power of 2 */
+
 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *bmap)
 {
 	struct inode *dat = nilfs_bmap_get_dat(bmap);
 	unsigned long entries_per_group = nilfs_palloc_entries_per_group(dat);
-	unsigned long group = bmap->b_inode->i_ino / entries_per_group;
+	unsigned long group;
+	u32 index;
+
+	BUILD_BUG_ON_NOT_POWER_OF_2(NILFS_BMAP_GROUP_DIV);
+
+	group = div_u64(bmap->b_inode->i_ino, entries_per_group);
+	index = bmap->b_inode->i_ino & (NILFS_BMAP_GROUP_DIV - 1);
 
 	return group * entries_per_group +
-		(bmap->b_inode->i_ino % NILFS_BMAP_GROUP_DIV) *
-		(entries_per_group / NILFS_BMAP_GROUP_DIV);
+	       index * (entries_per_group / NILFS_BMAP_GROUP_DIV);
 }
 
+
 static struct lock_class_key nilfs_bmap_dat_lock_key;
 static struct lock_class_key nilfs_bmap_mdt_lock_key;
 
diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
index c0ca4eedb0fe..1c41af2f91a6 100644
--- a/security/integrity/evm/evm_crypto.c
+++ b/security/integrity/evm/evm_crypto.c
@@ -144,6 +144,12 @@ static void hmac_add_misc(struct shash_desc *desc, struct inode *inode,
 			  char type, char *digest)
 {
 	struct h_misc {
+		/*
+		 * Although inode->i_ino is now u64, this field remains
+		 * unsigned long to allow existing HMAC and signatures from
+		 * 32-bit hosts to continue working when i_ino hasn't changed
+		 * and fits in a u32.
+		 */
 		unsigned long ino;
 		__u32 generation;
 		uid_t uid;