Commit 6acf7860 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

zloop: advertise a volatile write cache 



Zloop is file system backed and thus needs to sync the underlying file
system to persist data.  Set BLK_FEAT_WRITE_CACHE so that the block
layer actually send flush commands, and fix the flush implementation
as sync_filesystem requires s_umount to be held and the code currently
misses that.

Fixes: eb0570c7 ("block: new zoned loop block device driver")
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 0d195d3b

drivers/block/zloop.c

+18 −6
Original line number Diff line number Diff line
@@ -542,6 +542,21 @@ static void zloop_rw(struct zloop_cmd *cmd) 
	zloop_put_cmd(cmd);

}



/*

 * Sync the entire FS containing the zone files instead of walking all files.

 */

static int zloop_flush(struct zloop_device *zlo)

{

	struct super_block *sb = file_inode(zlo->data_dir)->i_sb;

	int ret;



	down_read(&sb->s_umount);

	ret = sync_filesystem(sb);

	up_read(&sb->s_umount);



	return ret;

}



static void zloop_handle_cmd(struct zloop_cmd *cmd)

{

	struct request *rq = blk_mq_rq_from_pdu(cmd);
@@ -562,11 +577,7 @@ static void zloop_handle_cmd(struct zloop_cmd *cmd) 
		zloop_rw(cmd);

		return;

	case REQ_OP_FLUSH:

		/*

		 * Sync the entire FS containing the zone files instead of

		 * walking all files

		 */

		cmd->ret = sync_filesystem(file_inode(zlo->data_dir)->i_sb);

		cmd->ret = zloop_flush(zlo);

		break;

	case REQ_OP_ZONE_RESET:

		cmd->ret = zloop_reset_zone(zlo, rq_zone_no(rq));
@@ -981,7 +992,8 @@ static int zloop_ctl_add(struct zloop_options *opts) 
	struct queue_limits lim = {

		.max_hw_sectors		= SZ_1M >> SECTOR_SHIFT,

		.chunk_sectors		= opts->zone_size,

		.features		= BLK_FEAT_ZONED,

		.features		= BLK_FEAT_ZONED | BLK_FEAT_WRITE_CACHE,



	};

	unsigned int nr_zones, i, j;

	struct zloop_device *zlo;