From 50c8c995eace63599ee956980b8e525fbe6a089b Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Mon, 26 Sep 2016 12:54:26 +0800 Subject: btrfs-progs: Return more meaningful value for btrfs_read_deve_super 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 Signed-off-by: David Sterba --- disk-io.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/disk-io.c b/disk-io.c index 854c2855..2052bb3d 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 -ENOENT 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; } -- cgit v1.2.3