• Brian Foster's avatar
    xfs: skip bmbt block ino validation during owner change · 1e4239ec
    Brian Foster authored
    commit 99c794c6 upstream.
    
    Extent swap uses xfs_btree_visit_blocks() to fix up bmbt block
    owners on v5 (!rmapbt) filesystems. The bmbt scan uses
    xfs_btree_lookup_get_block() to read bmbt blocks which verifies the
    current owner of the block against the parent inode of the bmbt.
    This works during extent swap because the bmbt owners are updated to
    the opposite inode number before the inode extent forks are swapped.
    
    The modified bmbt blocks are marked as ordered buffers which allows
    everything to commit in a single transaction. If the transaction
    commits to the log and the system crashes such that recovery of the
    extent swap is required, log recovery restarts the bmbt scan to fix
    up any bmbt blocks that may have not been written back before the
    crash. The log recovery bmbt scan occurs after the inode forks have
    been swapped, however. This causes the bmbt block owner verification
    to fail, leads to log recovery failure and requires xfs_repair to
    zap the log to recover.
    
    Define a new invalid inode owner flag to inform the btree block
    lookup mechanism that the current inode may be invalid with respect
    to the current owner of the bmbt block. Set this flag on the cursor
    used for change owner scans to allow this operation to work at
    runtime and during log recovery.
    Signed-off-by: default avatarBrian Foster <bfoster@redhat.com>
    Fixes: bb3be7e7 ("xfs: check for bogus values in btree block headers")
    Cc: stable@vger.kernel.org
    Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
    Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
    Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    1e4239ec
xfs_btree.h 16.4 KB