btrfs_read_dev_super() only returns 0 or -1, which doesn't really help,
caller won't know if it's caused by bad superblock or superblock out of
range.
Return -errno if pread64() return -1, and return -EOF if none or part of
the super is read out, and return what check_super() returned.
So caller can get -EIO to catch real corrupted super blocks.
Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com>
---
changelog:
v2:
Use better return values from pread64() and check_super().
---
disk-io.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/disk-io.c b/disk-io.c
index 854c285..4c5be08 100644
--- a/disk-io.c
+++ b/disk-io.c
@@ -1590,14 +1590,20 @@ int btrfs_read_dev_super(int fd, struct
btrfs_super_block *sb, u64 sb_bytenr,
if (sb_bytenr != BTRFS_SUPER_INFO_OFFSET) {
ret = pread64(fd, buf, BTRFS_SUPER_INFO_SIZE, sb_bytenr);
+ /* real error */
+ if (ret < 0)
+ return -errno;
+
+ /* Not large enough sb, return EOF instead of normal -EIO */
if (ret < BTRFS_SUPER_INFO_SIZE)
- return -1;
+ return -ENOENT;
if (btrfs_super_bytenr(buf) != sb_bytenr)
- return -1;
+ return -EIO;
- if (check_super(buf, sbflags))
- return -1;
+ ret = check_super(buf, sbflags);
+ if (ret < 0)
+ return ret;
memcpy(sb, buf, BTRFS_SUPER_INFO_SIZE);
return 0;
}
--
2.10.0
--
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