Re: [PATCH 05/11] xfs: factor out unmount record writing

Brian Foster
2020-03-05T18:07:08Z

On Wed, Mar 04, 2020 at 06:53:55PM +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> Separate out the unmount record writing from the rest of the
> ticket and log state futzing necessary to make it work. This is
> a no-op, just makes the code cleaner and places the unmount record
> formatting and writing alongside the commit record formatting and
> writing code.
>
> We can also get rid of the ticket flag clearing before the
> xlog_write() call because it no longer cares about the state of
> XLOG_TIC_INITED.
>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> ---

Reviewed-by: Brian Foster <bfoster@redhat.com>

> fs/xfs/xfs_log.c | 59 ++++++++++++++++++++++++++++--------------------
> 1 file changed, 35 insertions(+), 24 deletions(-)
>
> diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
> index 100eeaed4a7d..2e9f3baa7cc8 100644
> --- a/fs/xfs/xfs_log.c
> +++ b/fs/xfs/xfs_log.c
> @@ -485,6 +485,38 @@ xfs_log_reserve(
> * marked as with WANT_SYNC.
> */
>
> +/*
> + * Write out an unmount record using the ticket provided. We have to account for
> + * the data space used in the unmount ticket as this write is not done from a
> + * transaction context that has already done the accounting for us.
> + */
> +static int
> +xlog_write_unmount(
> + struct xlog *log,
> + struct xlog_ticket *ticket,
> + xfs_lsn_t *lsn,
> + uint flags)
> +{
> + /* the data section must be 32 bit size aligned */
> + struct xfs_unmount_log_format magic = {
> + .magic = XLOG_UNMOUNT_TYPE,
> + };
> + struct xfs_log_iovec reg = {
> + .i_addr = &magic,
> + .i_len = sizeof(magic),
> + .i_type = XLOG_REG_TYPE_UNMOUNT,
> + };
> + struct xfs_log_vec vec = {
> + .lv_niovecs = 1,
> + .lv_iovecp = &reg,
> + };
> +
> + /* account for space used by record data */
> + ticket->t_curr_res -= sizeof(magic);
> +
> + return xlog_write(log, &vec, ticket, lsn, NULL, flags);
> +}
> +
> /*
> * Write out the commit record of a transaction associated with the given
> * ticket to close off a running log write. Return the lsn of the commit record.
> @@ -843,31 +875,13 @@ xfs_log_mount_cancel(
> }
>
> /*
> - * Final log writes as part of unmount.
> - *
> - * Mark the filesystem clean as unmount happens. Note that during relocation
> - * this routine needs to be executed as part of source-bag while the
> - * deallocation must not be done until source-end.
> + * Mark the filesystem clean by writing an unmount record to the head of the
> + * log.
> */
> -
> -/* Actually write the unmount record to disk. */
> static void
> xfs_log_write_unmount_record(
> struct xfs_mount *mp)
> {
> - /* the data section must be 32 bit size aligned */
> - struct xfs_unmount_log_format magic = {
> - .magic = XLOG_UNMOUNT_TYPE,
> - };
> - struct xfs_log_iovec reg = {
> - .i_addr = &magic,
> - .i_len = sizeof(magic),
> - .i_type = XLOG_REG_TYPE_UNMOUNT,
> - };
> - struct xfs_log_vec vec = {
> - .lv_niovecs = 1,
> - .lv_iovecp = &reg,
> - };
> struct xlog *log = mp->m_log;
> struct xlog_in_core *iclog;
> struct xlog_ticket *tic = NULL;
> @@ -892,10 +906,7 @@ xfs_log_write_unmount_record(
> flags &= ~XLOG_UNMOUNT_TRANS;
> }
>
> - /* remove inited flag, and account for space used */
> - tic->t_flags = 0;
> - tic->t_curr_res -= sizeof(magic);
> - error = xlog_write(log, &vec, tic, &lsn, NULL, flags);
> + error = xlog_write_unmount(log, tic, &lsn, flags);
> /*
> * At this point, we're umounting anyway, so there's no point in
> * transitioning log state to IOERROR. Just continue...
> --
> 2.24.0.rc0
>