Commit 8f1d4983 authored by Chao Yu's avatar Chao Yu Committed by Jaegeuk Kim
Browse files

f2fs: compress: remove unneeded preallocation 



We will reserve iblocks for compression saved, so during compressed
cluster overwrite, we don't need to preallocate blocks for later
write.

In addition, it adds a bug_on to detect wrong reserved iblock number
in __f2fs_cluster_blocks().

Bug fix in the original patch by Jaegeuk:
If we released compressed blocks having an immutable bit, we can see less
number of compressed block addresses. Let's fix wrong BUG_ON.

Signed-off-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 8939a848

fs/f2fs/compress.c

+3 −24
Original line number Diff line number Diff line
@@ -926,6 +926,9 @@ static int __f2fs_cluster_blocks(struct inode *inode, 
					ret++;

			}

		}



		f2fs_bug_on(F2FS_I_SB(inode),

			!compr && ret != cluster_size && !IS_IMMUTABLE(inode));

	}

fail:

	f2fs_put_dnode(&dn);
@@ -984,21 +987,16 @@ static int prepare_compress_overwrite(struct compress_ctx *cc, 
	struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);

	struct address_space *mapping = cc->inode->i_mapping;

	struct page *page;

	struct dnode_of_data dn;

	sector_t last_block_in_bio;

	unsigned fgp_flag = FGP_LOCK | FGP_WRITE | FGP_CREAT;

	pgoff_t start_idx = start_idx_of_cluster(cc);

	int i, ret;

	bool prealloc;



retry:

	ret = f2fs_is_compressed_cluster(cc->inode, start_idx);

	if (ret <= 0)

		return ret;



	/* compressed case */

	prealloc = (ret < cc->cluster_size);



	ret = f2fs_init_compress_ctx(cc);

	if (ret)

		return ret;
@@ -1056,25 +1054,6 @@ static int prepare_compress_overwrite(struct compress_ctx *cc, 
		}

	}



	if (prealloc) {

		f2fs_do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, true);



		set_new_dnode(&dn, cc->inode, NULL, NULL, 0);



		for (i = cc->cluster_size - 1; i > 0; i--) {

			ret = f2fs_get_block(&dn, start_idx + i);

			if (ret) {

				i = cc->cluster_size;

				break;

			}



			if (dn.data_blkaddr != NEW_ADDR)

				break;

		}



		f2fs_do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, false);

	}



	if (likely(!ret)) {

		*fsdata = cc->rpages;

		*pagep = cc->rpages[offset_in_cluster(cc, index)];

fs/f2fs/file.c

+0 −4
Original line number Diff line number Diff line
@@ -85,10 +85,6 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf) 
			err = ret;

			goto err;

		} else if (ret) {

			if (ret < F2FS_I(inode)->i_cluster_size) {

				err = -EAGAIN;

				goto err;

			}

			need_alloc = false;

		}

	}