[PATCH] erofs: get rid of `buf->kmap_type`

[Gao Xiang]

After commit 927e5010ff5b ("erofs: use kmap_local_page() only for
erofs_bread()"), `buf->kmap_type` actually has no use at all.

Let's get rid of `buf->kmap_type` now.

Suggested-by: Al Viro <v...@zeniv.linux.org.uk>
Signed-off-by: Gao Xiang <hsiang...@linux.alibaba.com>
---
 fs/erofs/data.c     | 18 +++++-------------
 fs/erofs/internal.h |  1 -
 2 files changed, 5 insertions(+), 14 deletions(-)

diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index f741c3847ff2..d53979174aff 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -10,10 +10,10 @@
 
 void erofs_unmap_metabuf(struct erofs_buf *buf)
 {
-       if (buf->kmap_type == EROFS_KMAP)
-               kunmap_local(buf->base);
+       if (!buf->base)
+               return;
+       kunmap_local(buf->base);
        buf->base = NULL;
-       buf->kmap_type = EROFS_NO_KMAP;
 }
 
 void erofs_put_metabuf(struct erofs_buf *buf)
@@ -45,15 +45,8 @@ void *erofs_bread(struct erofs_buf *buf, erofs_off_t offset,
                        return folio;
        }
        buf->page = folio_file_page(folio, index);
-
-       if (buf->kmap_type == EROFS_NO_KMAP) {
-               if (type == EROFS_KMAP)
-                       buf->base = kmap_local_page(buf->page);
-               buf->kmap_type = type;
-       } else if (buf->kmap_type != type) {
-               DBG_BUGON(1);
-               return ERR_PTR(-EFAULT);
-       }
+       if (!buf->base && type == EROFS_KMAP)
+               buf->base = kmap_local_page(buf->page);
        if (type == EROFS_NO_KMAP)
                return NULL;
        return buf->base + (offset & ~PAGE_MASK);
@@ -352,7 +345,6 @@ static int erofs_iomap_end(struct inode *inode, loff_t pos, 
loff_t length,
                struct erofs_buf buf = {
                        .page = kmap_to_page(ptr),
                        .base = ptr,
-                       .kmap_type = EROFS_KMAP,
                };
 
                DBG_BUGON(iomap->type != IOMAP_INLINE);
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 9844ee8a07e5..01bbbd32b6b9 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -212,7 +212,6 @@ struct erofs_buf {
        struct file *file;
        struct page *page;
        void *base;
-       enum erofs_kmap_type kmap_type;
 };
 #define __EROFS_BUF_INITIALIZER        ((struct erofs_buf){ .page = NULL })
 
-- 
2.43.5