| Message ID | 20160926045426.14340-1-quwenruo@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Mon, Sep 26, 2016 at 12:54:26PM +0800, Qu Wenruo wrote: > 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 <quwenruo@cn.fujitsu.com> Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/disk-io.c b/disk-io.c index 854c285..2052bb3 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; }
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 <quwenruo@cn.fujitsu.com> --- changelog: v2: Use better return values from pread64() and check_super(). v3: Fix wrong comment --- disk-io.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)