[1/2] btrfs-progs: dump-super: improve error log

Commit Message

Anand Jain June 21, 2023, 3:41 p.m. UTC

Add more error info to help debug.

  $ ./btrfs inspect-internal dump-super -Ffa /dev/vdb10

  Before:
  ERROR: failed to read the superblock on /dev/vdb10 at 274877906944

  After:
  ERROR: failed to read the superblock on /dev/vdb10 at 274877906944
  read 0/4096 bytes

Signed-off-by: Anand Jain <[e-mail]>
---
 cmds/inspect-dump-super.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Patch

diff --git a/cmds/inspect-dump-super.c b/cmds/inspect-dump-super.c
index d62c3a85d9ca..4529b2308d7e 100644
--- a/cmds/inspect-dump-super.c
+++ b/cmds/inspect-dump-super.c
@@ -41,7 +41,8 @@  static int load_and_dump_sb(char *filename, int fd, u64 sb_bytenr, int full,
 		if (ret == 0 && errno == 0)
 			return 0;
 
-		error("failed to read the superblock on %s at %llu", filename, sb_bytenr);
+		error("Failed to read the superblock on %s at %llu read %llu/%d bytes",
+		       filename, sb_bytenr, ret, BTRFS_SUPER_INFO_SIZE);
 		error("error = '%m', errno = %d", errno);
 		return 1;
 	}