f2fs: compress: fix to assign cc.cluster_idx correctly

In f2fs_destroy_compress_ctx(), after f2fs_destroy_compress_ctx(),
cc.cluster_idx will be cleared w/ NULL_CLUSTER, f2fs_cluster_blocks()
may check wrong cluster metadata, fix it.

Fixes: 4c8ff709 ("f2fs: support data compression")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/compress.c

@@ -145,13 +145,14 @@ int f2fs_init_compress_ctx(struct compress_ctx *cc)
 	return cc->rpages ? 0 : -ENOMEM;
 }
 
-void f2fs_destroy_compress_ctx(struct compress_ctx *cc)
+void f2fs_destroy_compress_ctx(struct compress_ctx *cc, bool reuse)
 {
 	page_array_free(cc->inode, cc->rpages, cc->cluster_size);
 	cc->rpages = NULL;
 	cc->nr_rpages = 0;
 	cc->nr_cpages = 0;
-	cc->cluster_idx = NULL_CLUSTER;
+	if (!reuse)
+		cc->cluster_idx = NULL_CLUSTER;
 }
 
 void f2fs_compress_ctx_add_page(struct compress_ctx *cc, struct page *page)
@@ -1034,7 +1035,7 @@ static int prepare_compress_overwrite(struct compress_ctx *cc,
 		ret = f2fs_read_multi_pages(cc, &bio, cc->cluster_size,
 					&last_block_in_bio, false, true);
 		f2fs_put_rpages(cc);
-		f2fs_destroy_compress_ctx(cc);
+		f2fs_destroy_compress_ctx(cc, true);
 		if (ret)
 			goto out;
 		if (bio)
@@ -1061,7 +1062,7 @@ static int prepare_compress_overwrite(struct compress_ctx *cc,
 release_and_retry:
 			f2fs_put_rpages(cc);
 			f2fs_unlock_rpages(cc, i + 1);
-			f2fs_destroy_compress_ctx(cc);
+			f2fs_destroy_compress_ctx(cc, true);
 			goto retry;
 		}
 	}
@@ -1094,7 +1095,7 @@ static int prepare_compress_overwrite(struct compress_ctx *cc,
 unlock_pages:
 	f2fs_put_rpages(cc);
 	f2fs_unlock_rpages(cc, i);
-	f2fs_destroy_compress_ctx(cc);
+	f2fs_destroy_compress_ctx(cc, true);
 out:
 	return ret;
 }
@@ -1130,7 +1131,7 @@ bool f2fs_compress_write_end(struct inode *inode, void *fsdata,
 		set_cluster_dirty(&cc);
 
 	f2fs_put_rpages_wbc(&cc, NULL, false, 1);
-	f2fs_destroy_compress_ctx(&cc);
+	f2fs_destroy_compress_ctx(&cc, false);
 
 	return first_index;
 }
@@ -1350,7 +1351,7 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc,
 	f2fs_put_rpages(cc);
 	page_array_free(cc->inode, cc->cpages, cc->nr_cpages);
 	cc->cpages = NULL;
-	f2fs_destroy_compress_ctx(cc);
+	f2fs_destroy_compress_ctx(cc, false);
 	return 0;
 
 out_destroy_crypt:
@@ -1512,7 +1513,7 @@ int f2fs_write_multi_pages(struct compress_ctx *cc,
 	err = f2fs_write_raw_pages(cc, submitted, wbc, io_type);
 	f2fs_put_rpages_wbc(cc, wbc, false, 0);
 destroy_out:
-	f2fs_destroy_compress_ctx(cc);
+	f2fs_destroy_compress_ctx(cc, false);
 	return err;
 }
 

fs/f2fs/data.c

@@ -2287,7 +2287,7 @@ static int f2fs_mpage_readpages(struct inode *inode,
 							max_nr_pages,
 							&last_block_in_bio,
 							rac != NULL, false);
-				f2fs_destroy_compress_ctx(&cc);
+				f2fs_destroy_compress_ctx(&cc, false);
 				if (ret)
 					goto set_error_page;
 			}
@@ -2332,7 +2332,7 @@ static int f2fs_mpage_readpages(struct inode *inode,
 							max_nr_pages,
 							&last_block_in_bio,
 							rac != NULL, false);
-				f2fs_destroy_compress_ctx(&cc);
+				f2fs_destroy_compress_ctx(&cc, false);
 			}
 		}
 #endif
@@ -3033,7 +3033,7 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
 		}
 	}
 	if (f2fs_compressed_file(inode))
-		f2fs_destroy_compress_ctx(&cc);
+		f2fs_destroy_compress_ctx(&cc, false);
 #endif
 	if (retry) {
 		index = 0;

fs/f2fs/f2fs.h

@@ -3956,7 +3956,7 @@ struct decompress_io_ctx *f2fs_alloc_dic(struct compress_ctx *cc);
 void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed);
 void f2fs_put_page_dic(struct page *page);
 int f2fs_init_compress_ctx(struct compress_ctx *cc);
-void f2fs_destroy_compress_ctx(struct compress_ctx *cc);
+void f2fs_destroy_compress_ctx(struct compress_ctx *cc, bool reuse);
 void f2fs_init_compress_info(struct f2fs_sb_info *sbi);
 int f2fs_init_page_array_cache(struct f2fs_sb_info *sbi);
 void f2fs_destroy_page_array_cache(struct f2fs_sb_info *sbi);