[RFC PATCH 09/19] mm: hugetlb: Use restore_reserve_on_error directly in filesystems

[Ackerley Tng <ackerleytng@google.com>]

Expose inode_resv_map() so that hugetlbfs can access its own resv_map.

Hide restore_reserve_on_error_vma(), that function is now only used
within mm/hugetlb.c.

Signed-off-by: Ackerley Tng <ackerleytng@google.com>
---
 fs/hugetlbfs/inode.c    |  2 +-
 include/linux/hugetlb.h | 21 +++++++++++++++++++--
 mm/hugetlb.c            | 13 -------------
 3 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 44e6ee9a856d..53f6a421499d 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -868,7 +868,7 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
 		__folio_mark_uptodate(folio);
 		error = hugetlb_add_to_page_cache(folio, mapping, index);
 		if (unlikely(error)) {
-			restore_reserve_on_error_vma(h, &pseudo_vma, addr, folio);
+			restore_reserve_on_error(inode_resv_map(inode), index, true, folio);
 			folio_put(folio);
 			mutex_unlock(&hugetlb_fault_mutex_table[hash]);
 			goto out;
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 02a2766d89a4..5fe9643826d7 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -568,6 +568,20 @@ static inline struct hugepage_subpool *subpool_inode(struct inode *inode)
 	return HUGETLBFS_SB(inode->i_sb)->spool;
 }
 
+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)->private_data;
+}
+
+
 #else /* !CONFIG_HUGETLBFS */
 
 #define is_file_hugepages(file)			false
@@ -588,6 +602,11 @@ static inline struct hugepage_subpool *subpool_inode(struct inode *inode)
 	return NULL;
 }
 
+static inline struct resv_map *inode_resv_map(struct inode *inode)
+{
+	return NULL;
+}
+
 #endif /* !CONFIG_HUGETLBFS */
 
 #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
@@ -762,8 +781,6 @@ int hugetlb_add_to_page_cache(struct folio *folio, struct address_space *mapping
 			pgoff_t idx);
 void restore_reserve_on_error(struct resv_map *resv, pgoff_t resv_index,
 			      bool may_share, struct folio *folio);
-void restore_reserve_on_error_vma(struct hstate *h, struct vm_area_struct *vma,
-				  unsigned long address, struct folio *folio);
 
 /* arch callback */
 int __init __alloc_bootmem_huge_page(struct hstate *h, int nid);
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 4675f9efeba4..540634aec181 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1091,19 +1091,6 @@ void resv_map_release(struct kref *ref)
 	kfree(resv_map);
 }
 
-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)->private_data;
-}
-
 static struct resv_map *vma_resv_map(struct vm_area_struct *vma)
 {
 	VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma);
-- 
2.41.0.rc0.172.g3f132b7071-goog