xfs: Decouple XFS_IBULK flags from XFS_IWALK flags

A future commit will add a new XFS_IBULK flag which will not have a
corresponding XFS_IWALK flag. In preparation for the change, this commit
separates XFS_IBULK_* flags from XFS_IWALK_* flags.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>

xfs: remove all *_ITER_CONTINUE values

Iterator functions already use 0 to signal "continue iterating", so get
rid of the #defines and just do it directly.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: remove all *_ITER_ABORT values

Use -ECANCELED to signal "stop iterating" instead of these magical
*_ITER_ABORT values, since it's duplicative.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: specify AG in bulk req

Add a new xfs_bulk_ireq flag to constrain the iteration to a single AG.
If the passed-in startino value is zero then we start with the first
inode in the AG that the user passes in; otherwise, we iterate only
within the same AG as the passed-in inode.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: poll waiting for quotacheck

Create a pwork destroy function that uses polling instead of
uninterruptible sleep to wait for work items to finish so that we can
touch the softlockup watchdog. IOWs, gross hack.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: multithreaded iwalk implementation

Create a parallel iwalk implementation and switch quotacheck to use it.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: refactor iwalk code to handle walking inobt records

Refactor xfs_iwalk_ag_start and xfs_iwalk_ag so that the bits that are
particular to bulkstat (trimming the start irec, starting inode
readahead, and skipping empty groups) can be controlled via flags in the
iwag structure.

This enables us to add a new function to walk all inobt records which
will be used for the new INUMBERS implementation in the next patch.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: create simplified inode walk function

Create a new iterator function to simplify walking inodes in an XFS
filesystem. This new iterator will replace the existing open-coded
walking that goes on in various places.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>