tree dc71999614e2041ef8a10f9ff797fd354823ccb6
parent e2bb92633615ad801c4ab56fdb3eba3c701b2a3c
author Brian Foster <bfoster@redhat.com> 1505682427 -0700
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1505888402 +0200

xfs: relog dirty buffers during swapext bmbt owner change

commit 2dd3d709fc4338681a3aa61658122fa8faa5a437 upstream.

The owner change bmbt scan that occurs during extent swap operations
does not handle ordered buffer failures. Buffers that cannot be
marked ordered must be physically logged so previously dirty ranges
of the buffer can be relogged in the transaction.

Since the bmbt scan may need to process and potentially log a large
number of blocks, we can't expect to complete this operation in a
single transaction. Update extent swap to use a permanent
transaction with enough log reservation to physically log a buffer.
Update the bmbt scan to physically log any buffers that cannot be
ordered and to terminate the scan with -EAGAIN. On -EAGAIN, the
caller rolls the transaction and restarts the scan. Finally, update
the bmbt scan helper function to skip bmbt blocks that already match
the expected owner so they are not reprocessed after scan restarts.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
[darrick: fix the xfs_trans_roll call]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>