Commit ffa04c1f authored by Dave Chinner's avatar Dave Chinner Committed by Dave Chinner
Browse files

xfs: embed the xlog_op_header in the unmount record 



Remove another case where xlog_write() has to prepend an opheader to
a log transaction. The unmount record + ophdr is smaller than the
minimum amount of space guaranteed to be free in an iclog (2 *
sizeof(ophdr)) and so we don't have to care about an unmount record
being split across 2 iclogs.

Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarChandan Babu R <chandan.babu@oracle.com>
Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
parent 6eaed95e

fs/xfs/xfs_log.c

+28 −11
Original line number Diff line number Diff line
@@ -901,12 +901,22 @@ xlog_write_unmount_record( 
	struct xlog		*log,

	struct xlog_ticket	*ticket)

{

	struct xfs_unmount_log_format ulf = {

	struct  {

		struct xlog_op_header ophdr;

		struct xfs_unmount_log_format ulf;

	} unmount_rec = {

		.ophdr = {

			.oh_clientid = XFS_LOG,

			.oh_tid = cpu_to_be32(ticket->t_tid),

			.oh_flags = XLOG_UNMOUNT_TRANS,

		},

		.ulf = {

			.magic = XLOG_UNMOUNT_TYPE,

		},

	};

	struct xfs_log_iovec reg = {

		.i_addr = &ulf,

		.i_len = sizeof(ulf),

		.i_addr = &unmount_rec,

		.i_len = sizeof(unmount_rec),

		.i_type = XLOG_REG_TYPE_UNMOUNT,

	};

	struct xfs_log_vec vec = {
@@ -914,8 +924,12 @@ xlog_write_unmount_record( 
		.lv_iovecp = &reg,

	};



	BUILD_BUG_ON((sizeof(struct xlog_op_header) +

		      sizeof(struct xfs_unmount_log_format)) !=

							sizeof(unmount_rec));



	/* account for space used by record data */

	ticket->t_curr_res -= sizeof(ulf);

	ticket->t_curr_res -= sizeof(unmount_rec);



	return xlog_write(log, NULL, &vec, ticket, XLOG_UNMOUNT_TRANS);

}
@@ -2253,6 +2267,8 @@ xlog_write_calc_vec_length( 


	/* Don't account for regions with embedded ophdrs */

	if (optype && headers > 0) {

		if (optype & XLOG_UNMOUNT_TRANS)

			headers--;

		if (optype & XLOG_START_TRANS) {

			ASSERT(headers >= 2);

			headers -= 2;
@@ -2458,12 +2474,11 @@ xlog_write( 


	/*

	 * If this is a commit or unmount transaction, we don't need a start

	 * record to be written.  We do, however, have to account for the

	 * commit or unmount header that gets written. Hence we always have

	 * to account for an extra xlog_op_header here for commit and unmount

	 * records.

	 * record to be written.  We do, however, have to account for the commit

	 * header that gets written. Hence we always have to account for an

	 * extra xlog_op_header here for commit records.

	 */

	if (optype & (XLOG_COMMIT_TRANS | XLOG_UNMOUNT_TRANS))

	if (optype & XLOG_COMMIT_TRANS)

		ticket->t_curr_res -= sizeof(struct xlog_op_header);

	if (ticket->t_curr_res < 0) {

		xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
@@ -2527,6 +2542,8 @@ xlog_write( 
				ophdr = reg->i_addr;

				if (index)

					optype &= ~XLOG_START_TRANS;

			} else if (optype & XLOG_UNMOUNT_TRANS) {

				ophdr = reg->i_addr;

			} else {

				ophdr = xlog_write_setup_ophdr(log, ptr,

							ticket, optype);
@@ -2557,7 +2574,7 @@ xlog_write( 
			/*

			 * Copy region.

			 *

			 * Commit and unmount records just log an opheader, so

			 * Commit records just log an opheader, so

			 * we can have empty payloads with no data region to

			 * copy.  Hence we only copy the payload if the vector

			 * says it has data to copy.