Instead of using i_private_data for resv_map pointer add the pointer
into hugetlbfs private part of the inode.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/hugetlbfs/inode.c    | 11 +++--------
 include/linux/hugetlb.h |  1 +
 mm/hugetlb.c            | 10 +---------
 3 files changed, 5 insertions(+), 17 deletions(-)

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 3f70c47981de..6ad02493adfd 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -622,13 +622,7 @@ static void hugetlbfs_evict_inode(struct inode *inode)
 	trace_hugetlbfs_evict_inode(inode);
 	remove_inode_hugepages(inode, 0, LLONG_MAX);
 
-	/*
-	 * Get the resv_map from the address space embedded in the inode.
-	 * This is the address space which points to any resv_map allocated
-	 * at inode creation time.  If this is a device special inode,
-	 * i_mapping may not point to the original address space.
-	 */
-	resv_map = (struct resv_map *)(&inode->i_data)->i_private_data;
+	resv_map = HUGETLBFS_I(inode)->resv_map;
 	/* Only regular and link inodes have associated reserve maps */
 	if (resv_map)
 		resv_map_release(&resv_map->refs);
@@ -907,6 +901,7 @@ static struct inode *hugetlbfs_get_root(struct super_block *sb,
 		simple_inode_init_ts(inode);
 		inode->i_op = &hugetlbfs_dir_inode_operations;
 		inode->i_fop = &simple_dir_operations;
+		HUGETLBFS_I(inode)->resv_map = NULL;
 		/* directory inodes start off with i_nlink == 2 (for "." entry) */
 		inc_nlink(inode);
 		lockdep_annotate_inode_mutex_key(inode);
@@ -950,7 +945,7 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
 				&hugetlbfs_i_mmap_rwsem_key);
 		inode->i_mapping->a_ops = &hugetlbfs_aops;
 		simple_inode_init_ts(inode);
-		inode->i_mapping->i_private_data = resv_map;
+		info->resv_map = resv_map;
 		info->seals = F_SEAL_SEAL;
 		switch (mode & S_IFMT) {
 		default:
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 65910437be1c..fc5462fe943f 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -518,6 +518,7 @@ static inline struct hugetlbfs_sb_info *HUGETLBFS_SB(struct super_block *sb)
 
 struct hugetlbfs_inode_info {
 	struct inode vfs_inode;
+	struct resv_map *resv_map;
 	unsigned int seals;
 };
 
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 327eaa4074d3..2ced2c8633d8 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1157,15 +1157,7 @@ void resv_map_release(struct kref *ref)
 
 static inline struct resv_map *inode_resv_map(struct inode *inode)
 {
-	/*
-	 * At inode evict time, i_mapping may not point to the original
-	 * address space within the inode.  This original address space
-	 * contains the pointer to the resv_map.  So, always use the
-	 * address space embedded within the inode.
-	 * The VERY common case is inode->mapping == &inode->i_data but,
-	 * this may not be true for device special inodes.
-	 */
-	return (struct resv_map *)(&inode->i_data)->i_private_data;
+	return HUGETLBFS_I(inode)->resv_map;
 }
 
 static struct resv_map *vma_resv_map(struct vm_area_struct *vma)
-- 
2.51.0