[Ocfs2-tools-devel] [PATCH] o2image: return error if pread64 failed in ocfs2_image_load_bitmap()

[piaojun]

In ocfs2_image_load_bitmap(), if pread64 failed, we need catch the
errno and return errno to upper callers. otherwise we may get the
incorrect 'arr_map' but 'o2image -I' execute successfully.

Signed-off-by: Jun Piao <piaojun at huawei.com>
---
 libocfs2/image.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/libocfs2/image.c b/libocfs2/image.c
index fe95530..460616d 100644
--- a/libocfs2/image.c
+++ b/libocfs2/image.c
@@ -163,7 +163,7 @@ errcode_t ocfs2_image_load_bitmap(ocfs2_filesys *ofs)
 	struct ocfs2_image_state *ost;
 	struct ocfs2_image_hdr *hdr;
 	uint64_t blk_off, bits_set;
-	int count, i, j, fd;
+	int count = 0, tmp, i, j, fd;
 	errcode_t ret;
 	char *blk;
 
@@ -216,10 +216,15 @@ 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
 		 */
-		count = pread64(fd, ost->ost_bmparr[i].arr_map,
-				ost->ost_bmpblksz, blk_off);
-		if (count < ost->ost_bmpblksz)
-			goto out;
+		while (count < ost->ost_bmpblksz) {
+			tmp = pread64(fd, ost->ost_bmparr[i].arr_map + count,
+				ost->ost_bmpblksz - count, blk_off + count);
+			if (tmp <= 0) {
+				ret = OCFS2_ET_IO;
+				goto out;
+			}
+			count += tmp;
+		}
 
 		/* add bits set in this bitmap */
 		for (j = 0; j < (ost->ost_bmpblksz * 8); j++)
-- 
1.9.5.msysgit.1