[Ocfs2-tools-devel] [PATCH 2/2] o2image: allocate bitmap blocks only for metadata blocks when installing image file

[piaojun]

We should only allocate bitmap blocks for metadata blocks, as user data
blocks won't be accessed during installing image file.

Signed-off-by: Jun Piao <piaojun at huawei.com>
---
 libocfs2/image.c | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/libocfs2/image.c b/libocfs2/image.c
index 68f4fda..8814a56 100644
--- a/libocfs2/image.c
+++ b/libocfs2/image.c
@@ -114,7 +114,7 @@ errcode_t ocfs2_image_load_bitmap(ocfs2_filesys *ofs)
 	int i, j, fd;
 	ssize_t count;
 	errcode_t ret;
-	char *blk = NULL;
+	char *blk = NULL, *buf = NULL;

 	ret = ocfs2_malloc0(sizeof(struct ocfs2_image_state), &ofs->ost);
 	if (ret)
@@ -125,6 +125,10 @@ errcode_t ocfs2_image_load_bitmap(ocfs2_filesys *ofs)
 	if (ret)
 		goto out;

+	ret = ocfs2_malloc0(ost->ost_bmpblksz, &buf);
+	if (ret)
+		goto out;
+
 	/* read ocfs2 image header */
 	ret = io_read_block(ofs->fs_io, 0, 1, blk);
 	if (ret)
@@ -165,6 +169,13 @@ errcode_t ocfs2_image_load_bitmap(ocfs2_filesys *ofs)
 		 * we don't use io_read_block as ocfs2 image bitmap block size
 		 * could be different from filesystem block size
 		 */
+		ret = posix_memalign((void **)&ost->ost_bmparr[i].arr_map,
+				OCFS2_MAX_BLOCKSIZE, ost->ost_bmpblksz);
+		if (ret) {
+			ret = OCFS2_ET_NO_MEMORY;
+			goto out;
+		}
+
 		count = pread64(fd, ost->ost_bmparr[i].arr_map,
 				ost->ost_bmpblksz, blk_off);
 		if (count < 0) {
@@ -172,6 +183,16 @@ errcode_t ocfs2_image_load_bitmap(ocfs2_filesys *ofs)
 			goto out;
 		}

+		/*
+		 * we do not need 'arr_map' which none bit is set,
+		 * so free it to save memory.
+		 */
+		if (!memcmp(ost->ost_bmparr[i].arr_map, buf,
+				ost->ost_bmpblksz)) {
+			ocfs2_free(&ost->ost_bmparr[i].arr_map);
+			continue;
+		}
+
 		/* add bits set in this bitmap */
 		for (j = 0; j < (ost->ost_bmpblksz * 8); j++)
 			if (ocfs2_test_bit(j, ost->ost_bmparr[i].arr_map))
@@ -183,6 +204,8 @@ errcode_t ocfs2_image_load_bitmap(ocfs2_filesys *ofs)
 out:
 	if (blk)
 		ocfs2_free(&blk);
+	if (buf)
+		ocfs2_free(&buf);
 	if (ret) {
 		ocfs2_image_free_bitmap(ofs);
 		ocfs2_free(&ofs->ost);
--