staging: erofs: complete error handing of z_erofs_map_blocks_iter

This patch completes error handing of z_erofs_map_blocks_iter
and vle_get_logical_extent_head, including no memory and
io error cases.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index 1e89ff6..94c35b8 100644 (file)
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -1500,7 +1500,11 @@ vle_get_logical_extent_head(const struct vle_map_blocks_iter_ctx *ctx,
                unlock_page(mpage);
                put_page(mpage);
 
-               mpage = erofs_get_meta_page_nofail(ctx->sb, mblk, false);
+               mpage = erofs_get_meta_page(ctx->sb, mblk, false);
+               if (IS_ERR(mpage)) {
+                       *ctx->mpage_ret = NULL;
+                       return PTR_ERR(mpage);
+               }
                *ctx->mpage_ret = mpage;
                *ctx->kaddr_ret = kmap_atomic(mpage);
        }
@@ -1511,9 +1515,12 @@ vle_get_logical_extent_head(const struct vle_map_blocks_iter_ctx *ctx,
        switch (cluster_type) {
        case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
                delta0 = le16_to_cpu(di->di_u.delta[0]);
-               DBG_BUGON(!delta0);
-               DBG_BUGON(lcn < delta0);
-
+               if (unlikely(!delta0 || delta0 > lcn)) {
+                       errln("invalid NONHEAD dl0 %u at lcn %u of nid %llu",
+                             delta0, lcn, EROFS_V(ctx->inode)->nid);
+                       DBG_BUGON(1);
+                       return -EIO;
+               }
                return vle_get_logical_extent_head(ctx,
                        lcn - delta0, ofs, pblk, flags);
        case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
@@ -1526,7 +1533,10 @@ vle_get_logical_extent_head(const struct vle_map_blocks_iter_ctx *ctx,
                *pblk = le32_to_cpu(di->di_u.blkaddr);
                break;
        default:
-               BUG_ON(1);
+               errln("unknown cluster type %u at lcn %u of nid %llu",
+                     cluster_type, lcn, EROFS_V(ctx->inode)->nid);
+               DBG_BUGON(1);
+               return -EIO;
        }
        return 0;
 }
@@ -1583,7 +1593,11 @@ int z_erofs_map_blocks_iter(struct inode *inode,
                if (mpage != NULL)
                        put_page(mpage);
 
-               mpage = erofs_get_meta_page_nofail(ctx.sb, mblk, false);
+               mpage = erofs_get_meta_page(ctx.sb, mblk, false);
+               if (IS_ERR(mpage)) {
+                       err = PTR_ERR(mpage);
+                       goto out;
+               }
                *mpage_ret = mpage;
        } else {
                lock_page(mpage);
@@ -1646,8 +1660,11 @@ int z_erofs_map_blocks_iter(struct inode *inode,
                                                  &pblk, &map->m_flags);
                mpage = *mpage_ret;
 
-               if (unlikely(err))
-                       goto unmap_out;
+               if (unlikely(err)) {
+                       if (mpage)
+                               goto unmap_out;
+                       goto out;
+               }
                break;
        default:
                errln("unknown cluster type %u at offset %llu of nid %llu",
@@ -1671,7 +1688,7 @@ out:
                map->m_llen, map->m_plen, map->m_flags);
 
        /* aggressively BUG_ON iff CONFIG_EROFS_FS_DEBUG is on */
-       DBG_BUGON(err < 0);
+       DBG_BUGON(err < 0 && err != -ENOMEM);
        return err;
 }