From patchwork Mon Apr 8 01:41:13 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Damien Le Moal X-Patchwork-Id: 13620397 X-Patchwork-Delegate: snitzer@redhat.com Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 12DA61DFED; Mon, 8 Apr 2024 01:41:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712540516; cv=none; b=FATN6fwwnV+9icGSZYT4K9bTRmB1z+ADB8tMMlI6zhGeq1i1jjYn+YRb9r31qeKlJJnz/Wjzu1qwj268KFOz1RJ/oxsNwHl70UhTvGcX5vCkT9dZ3Q7JjnYzCPsflsrUQ6dIzEuV8+nlcQ1DqyOFxOtG4g8+g9QGu/TwHOvaptE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712540516; c=relaxed/simple; bh=aRHhPTGLIm/zdnNcbaI5GdZADpSFi9+YnikD24h7e+A=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OJotYFRPMQJwpEH8abR3XHq9Me7s52Kvc5Uw4Y4i/NNcvnm2kV5sxNSQLLFPccF0PZgcjtDOQlzbuYcEh+ozJ1qPAmXM8Xv6F4tC/UTf+suyei0ceKXCXm99zI9lOSVyFL45S/9zUSle/ui3TpFVST9swSfO/LnJg1SDlp8Z3FY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YRncQiEG; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="YRncQiEG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90D62C433C7; Mon, 8 Apr 2024 01:41:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1712540515; bh=aRHhPTGLIm/zdnNcbaI5GdZADpSFi9+YnikD24h7e+A=; h=From:To:Subject:Date:In-Reply-To:References:From; b=YRncQiEGpEPGDtFA6JEOyz0pB2UerBzUP9yClPjfM49gd/sMBn4+PYfmxdkCvqKUO v377r2KdnN17GunOkMhqgF3Vbxy/DHJyM3rz/WAMdrZdxPRH21W8zGnEMdvnt1x4Nr Tj2F2y26dFmsEQMj7JPE1RvrYC0TdKCdxN8Dq6cko2ImPbg04wEA2/7d6tXyqiqucn eL2pl3F5l4oBJRlbPuS8uPePnVpCOs9icvOFwoXaXl8D8WoVhpPtH1vpvkEsiCCqtv 15D3BSGGl9LjuXKSMnrkKx905aasW4o4TxkamWMXw6jXaI1FYmcor8ZsfMT0h+7lU5 rOIrv5Fr5qeAA== From: Damien Le Moal To: linux-block@vger.kernel.org, Jens Axboe , linux-scsi@vger.kernel.org, "Martin K . Petersen" , dm-devel@lists.linux.dev, Mike Snitzer , linux-nvme@lists.infradead.org, Keith Busch , Christoph Hellwig Subject: [PATCH v7 13/28] scsi: sd: Use the block layer zone append emulation Date: Mon, 8 Apr 2024 10:41:13 +0900 Message-ID: <20240408014128.205141-14-dlemoal@kernel.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240408014128.205141-1-dlemoal@kernel.org> References: <20240408014128.205141-1-dlemoal@kernel.org> Precedence: bulk X-Mailing-List: dm-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Set the request queue of a TYPE_ZBC device as needing zone append emulation by setting the device queue max_zone_append_sectors limit to 0. This enables the block layer generic implementation provided by zone write plugging. With this, the sd driver will never see a REQ_OP_ZONE_APPEND request and the zone append emulation code implemented in sd_zbc.c can be removed. Signed-off-by: Damien Le Moal Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Bart Van Assche Tested-by: Hans Holmberg Tested-by: Dennis Maisenbacher Reviewed-by: Martin K. Petersen --- drivers/scsi/sd.c | 8 - drivers/scsi/sd.h | 19 --- drivers/scsi/sd_zbc.c | 335 ++---------------------------------------- 3 files changed, 10 insertions(+), 352 deletions(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 58fdf679341d..03ec24c8bd77 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -1260,12 +1260,6 @@ static blk_status_t sd_setup_read_write_cmnd(struct scsi_cmnd *cmd) } } - if (req_op(rq) == REQ_OP_ZONE_APPEND) { - ret = sd_zbc_prepare_zone_append(cmd, &lba, nr_blocks); - if (ret) - goto fail; - } - fua = rq->cmd_flags & REQ_FUA ? 0x8 : 0; dix = scsi_prot_sg_count(cmd); dif = scsi_host_dif_capable(cmd->device->host, sdkp->protection_type); @@ -1348,7 +1342,6 @@ static blk_status_t sd_init_command(struct scsi_cmnd *cmd) return sd_setup_flush_cmnd(cmd); case REQ_OP_READ: case REQ_OP_WRITE: - case REQ_OP_ZONE_APPEND: return sd_setup_read_write_cmnd(cmd); case REQ_OP_ZONE_RESET: return sd_zbc_setup_zone_mgmt_cmnd(cmd, ZO_RESET_WRITE_POINTER, @@ -3979,7 +3972,6 @@ static void scsi_disk_release(struct device *dev) struct scsi_disk *sdkp = to_scsi_disk(dev); ida_free(&sd_index_ida, sdkp->index); - sd_zbc_free_zone_info(sdkp); put_device(&sdkp->device->sdev_gendev); free_opal_dev(sdkp->opal_dev); diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h index 5c4285a582b2..49dd600bfa48 100644 --- a/drivers/scsi/sd.h +++ b/drivers/scsi/sd.h @@ -104,12 +104,6 @@ struct scsi_disk { * between zone starting LBAs is constant. */ u32 zone_starting_lba_gran; - u32 *zones_wp_offset; - spinlock_t zones_wp_offset_lock; - u32 *rev_wp_offset; - struct mutex rev_mutex; - struct work_struct zone_wp_offset_work; - char *zone_wp_update_buf; #endif atomic_t openers; sector_t capacity; /* size in logical blocks */ @@ -245,7 +239,6 @@ static inline int sd_is_zoned(struct scsi_disk *sdkp) #ifdef CONFIG_BLK_DEV_ZONED -void sd_zbc_free_zone_info(struct scsi_disk *sdkp); int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 buf[SD_BUF_SIZE]); int sd_zbc_revalidate_zones(struct scsi_disk *sdkp); blk_status_t sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd *cmd, @@ -255,13 +248,8 @@ unsigned int sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes, int sd_zbc_report_zones(struct gendisk *disk, sector_t sector, unsigned int nr_zones, report_zones_cb cb, void *data); -blk_status_t sd_zbc_prepare_zone_append(struct scsi_cmnd *cmd, sector_t *lba, - unsigned int nr_blocks); - #else /* CONFIG_BLK_DEV_ZONED */ -static inline void sd_zbc_free_zone_info(struct scsi_disk *sdkp) {} - static inline int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 buf[SD_BUF_SIZE]) { return 0; @@ -285,13 +273,6 @@ static inline unsigned int sd_zbc_complete(struct scsi_cmnd *cmd, return good_bytes; } -static inline blk_status_t sd_zbc_prepare_zone_append(struct scsi_cmnd *cmd, - sector_t *lba, - unsigned int nr_blocks) -{ - return BLK_STS_TARGET; -} - #define sd_zbc_report_zones NULL #endif /* CONFIG_BLK_DEV_ZONED */ diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c index 26af5ab7d7c1..d0ead9858954 100644 --- a/drivers/scsi/sd_zbc.c +++ b/drivers/scsi/sd_zbc.c @@ -23,36 +23,6 @@ #define CREATE_TRACE_POINTS #include "sd_trace.h" -/** - * sd_zbc_get_zone_wp_offset - Get zone write pointer offset. - * @zone: Zone for which to return the write pointer offset. - * - * Return: offset of the write pointer from the start of the zone. - */ -static unsigned int sd_zbc_get_zone_wp_offset(struct blk_zone *zone) -{ - if (zone->type == ZBC_ZONE_TYPE_CONV) - return 0; - - switch (zone->cond) { - case BLK_ZONE_COND_IMP_OPEN: - case BLK_ZONE_COND_EXP_OPEN: - case BLK_ZONE_COND_CLOSED: - return zone->wp - zone->start; - case BLK_ZONE_COND_FULL: - return zone->len; - case BLK_ZONE_COND_EMPTY: - case BLK_ZONE_COND_OFFLINE: - case BLK_ZONE_COND_READONLY: - default: - /* - * Offline and read-only zones do not have a valid - * write pointer. Use 0 as for an empty zone. - */ - return 0; - } -} - /* Whether or not a SCSI zone descriptor describes a gap zone. */ static bool sd_zbc_is_gap_zone(const u8 buf[64]) { @@ -121,9 +91,6 @@ static int sd_zbc_parse_report(struct scsi_disk *sdkp, const u8 buf[64], if (ret) return ret; - if (sdkp->rev_wp_offset) - sdkp->rev_wp_offset[idx] = sd_zbc_get_zone_wp_offset(&zone); - return 0; } @@ -347,123 +314,6 @@ static blk_status_t sd_zbc_cmnd_checks(struct scsi_cmnd *cmd) return BLK_STS_OK; } -#define SD_ZBC_INVALID_WP_OFST (~0u) -#define SD_ZBC_UPDATING_WP_OFST (SD_ZBC_INVALID_WP_OFST - 1) - -static int sd_zbc_update_wp_offset_cb(struct blk_zone *zone, unsigned int idx, - void *data) -{ - struct scsi_disk *sdkp = data; - - lockdep_assert_held(&sdkp->zones_wp_offset_lock); - - sdkp->zones_wp_offset[idx] = sd_zbc_get_zone_wp_offset(zone); - - return 0; -} - -/* - * An attempt to append a zone triggered an invalid write pointer error. - * Reread the write pointer of the zone(s) in which the append failed. - */ -static void sd_zbc_update_wp_offset_workfn(struct work_struct *work) -{ - struct scsi_disk *sdkp; - unsigned long flags; - sector_t zno; - int ret; - - sdkp = container_of(work, struct scsi_disk, zone_wp_offset_work); - - spin_lock_irqsave(&sdkp->zones_wp_offset_lock, flags); - for (zno = 0; zno < sdkp->zone_info.nr_zones; zno++) { - if (sdkp->zones_wp_offset[zno] != SD_ZBC_UPDATING_WP_OFST) - continue; - - spin_unlock_irqrestore(&sdkp->zones_wp_offset_lock, flags); - ret = sd_zbc_do_report_zones(sdkp, sdkp->zone_wp_update_buf, - SD_BUF_SIZE, - zno * sdkp->zone_info.zone_blocks, true); - spin_lock_irqsave(&sdkp->zones_wp_offset_lock, flags); - if (!ret) - sd_zbc_parse_report(sdkp, sdkp->zone_wp_update_buf + 64, - zno, sd_zbc_update_wp_offset_cb, - sdkp); - } - spin_unlock_irqrestore(&sdkp->zones_wp_offset_lock, flags); - - scsi_device_put(sdkp->device); -} - -/** - * sd_zbc_prepare_zone_append() - Prepare an emulated ZONE_APPEND command. - * @cmd: the command to setup - * @lba: the LBA to patch - * @nr_blocks: the number of LBAs to be written - * - * Called from sd_setup_read_write_cmnd() for REQ_OP_ZONE_APPEND. - * @sd_zbc_prepare_zone_append() handles the necessary zone wrote locking and - * patching of the lba for an emulated ZONE_APPEND command. - * - * In case the cached write pointer offset is %SD_ZBC_INVALID_WP_OFST it will - * schedule a REPORT ZONES command and return BLK_STS_IOERR. - */ -blk_status_t sd_zbc_prepare_zone_append(struct scsi_cmnd *cmd, sector_t *lba, - unsigned int nr_blocks) -{ - struct request *rq = scsi_cmd_to_rq(cmd); - struct scsi_disk *sdkp = scsi_disk(rq->q->disk); - unsigned int wp_offset, zno = blk_rq_zone_no(rq); - unsigned long flags; - blk_status_t ret; - - ret = sd_zbc_cmnd_checks(cmd); - if (ret != BLK_STS_OK) - return ret; - - if (!blk_rq_zone_is_seq(rq)) - return BLK_STS_IOERR; - - /* Unlock of the write lock will happen in sd_zbc_complete() */ - if (!blk_req_zone_write_trylock(rq)) - return BLK_STS_ZONE_RESOURCE; - - spin_lock_irqsave(&sdkp->zones_wp_offset_lock, flags); - wp_offset = sdkp->zones_wp_offset[zno]; - switch (wp_offset) { - case SD_ZBC_INVALID_WP_OFST: - /* - * We are about to schedule work to update a zone write pointer - * offset, which will cause the zone append command to be - * requeued. So make sure that the scsi device does not go away - * while the work is being processed. - */ - if (scsi_device_get(sdkp->device)) { - ret = BLK_STS_IOERR; - break; - } - sdkp->zones_wp_offset[zno] = SD_ZBC_UPDATING_WP_OFST; - schedule_work(&sdkp->zone_wp_offset_work); - fallthrough; - case SD_ZBC_UPDATING_WP_OFST: - ret = BLK_STS_DEV_RESOURCE; - break; - default: - wp_offset = sectors_to_logical(sdkp->device, wp_offset); - if (wp_offset + nr_blocks > sdkp->zone_info.zone_blocks) { - ret = BLK_STS_IOERR; - break; - } - - trace_scsi_prepare_zone_append(cmd, *lba, wp_offset); - *lba += wp_offset; - } - spin_unlock_irqrestore(&sdkp->zones_wp_offset_lock, flags); - if (ret) - blk_req_zone_write_unlock(rq); - return ret; -} - /** * sd_zbc_setup_zone_mgmt_cmnd - Prepare a zone ZBC_OUT command. The operations * can be RESET WRITE POINTER, OPEN, CLOSE or FINISH. @@ -504,96 +354,6 @@ blk_status_t sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd *cmd, return BLK_STS_OK; } -static bool sd_zbc_need_zone_wp_update(struct request *rq) -{ - switch (req_op(rq)) { - case REQ_OP_ZONE_APPEND: - case REQ_OP_ZONE_FINISH: - case REQ_OP_ZONE_RESET: - case REQ_OP_ZONE_RESET_ALL: - return true; - case REQ_OP_WRITE: - case REQ_OP_WRITE_ZEROES: - return blk_rq_zone_is_seq(rq); - default: - return false; - } -} - -/** - * sd_zbc_zone_wp_update - Update cached zone write pointer upon cmd completion - * @cmd: Completed command - * @good_bytes: Command reply bytes - * - * Called from sd_zbc_complete() to handle the update of the cached zone write - * pointer value in case an update is needed. - */ -static unsigned int sd_zbc_zone_wp_update(struct scsi_cmnd *cmd, - unsigned int good_bytes) -{ - int result = cmd->result; - struct request *rq = scsi_cmd_to_rq(cmd); - struct scsi_disk *sdkp = scsi_disk(rq->q->disk); - unsigned int zno = blk_rq_zone_no(rq); - enum req_op op = req_op(rq); - unsigned long flags; - - /* - * If we got an error for a command that needs updating the write - * pointer offset cache, we must mark the zone wp offset entry as - * invalid to force an update from disk the next time a zone append - * command is issued. - */ - spin_lock_irqsave(&sdkp->zones_wp_offset_lock, flags); - - if (result && op != REQ_OP_ZONE_RESET_ALL) { - if (op == REQ_OP_ZONE_APPEND) { - /* Force complete completion (no retry) */ - good_bytes = 0; - scsi_set_resid(cmd, blk_rq_bytes(rq)); - } - - /* - * Force an update of the zone write pointer offset on - * the next zone append access. - */ - if (sdkp->zones_wp_offset[zno] != SD_ZBC_UPDATING_WP_OFST) - sdkp->zones_wp_offset[zno] = SD_ZBC_INVALID_WP_OFST; - goto unlock_wp_offset; - } - - switch (op) { - case REQ_OP_ZONE_APPEND: - trace_scsi_zone_wp_update(cmd, rq->__sector, - sdkp->zones_wp_offset[zno], good_bytes); - rq->__sector += sdkp->zones_wp_offset[zno]; - fallthrough; - case REQ_OP_WRITE_ZEROES: - case REQ_OP_WRITE: - if (sdkp->zones_wp_offset[zno] < sd_zbc_zone_sectors(sdkp)) - sdkp->zones_wp_offset[zno] += - good_bytes >> SECTOR_SHIFT; - break; - case REQ_OP_ZONE_RESET: - sdkp->zones_wp_offset[zno] = 0; - break; - case REQ_OP_ZONE_FINISH: - sdkp->zones_wp_offset[zno] = sd_zbc_zone_sectors(sdkp); - break; - case REQ_OP_ZONE_RESET_ALL: - memset(sdkp->zones_wp_offset, 0, - sdkp->zone_info.nr_zones * sizeof(unsigned int)); - break; - default: - break; - } - -unlock_wp_offset: - spin_unlock_irqrestore(&sdkp->zones_wp_offset_lock, flags); - - return good_bytes; -} - /** * sd_zbc_complete - ZBC command post processing. * @cmd: Completed command @@ -619,11 +379,7 @@ unsigned int sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes, * so be quiet about the error. */ rq->rq_flags |= RQF_QUIET; - } else if (sd_zbc_need_zone_wp_update(rq)) - good_bytes = sd_zbc_zone_wp_update(cmd, good_bytes); - - if (req_op(rq) == REQ_OP_ZONE_APPEND) - blk_req_zone_write_unlock(rq); + } return good_bytes; } @@ -780,46 +536,6 @@ static void sd_zbc_print_zones(struct scsi_disk *sdkp) sdkp->zone_info.zone_blocks); } -static int sd_zbc_init_disk(struct scsi_disk *sdkp) -{ - sdkp->zones_wp_offset = NULL; - spin_lock_init(&sdkp->zones_wp_offset_lock); - sdkp->rev_wp_offset = NULL; - mutex_init(&sdkp->rev_mutex); - INIT_WORK(&sdkp->zone_wp_offset_work, sd_zbc_update_wp_offset_workfn); - sdkp->zone_wp_update_buf = kzalloc(SD_BUF_SIZE, GFP_KERNEL); - if (!sdkp->zone_wp_update_buf) - return -ENOMEM; - - return 0; -} - -void sd_zbc_free_zone_info(struct scsi_disk *sdkp) -{ - if (!sdkp->zone_wp_update_buf) - return; - - /* Serialize against revalidate zones */ - mutex_lock(&sdkp->rev_mutex); - - kvfree(sdkp->zones_wp_offset); - sdkp->zones_wp_offset = NULL; - kfree(sdkp->zone_wp_update_buf); - sdkp->zone_wp_update_buf = NULL; - - sdkp->early_zone_info = (struct zoned_disk_info){ }; - sdkp->zone_info = (struct zoned_disk_info){ }; - - mutex_unlock(&sdkp->rev_mutex); -} - -static void sd_zbc_revalidate_zones_cb(struct gendisk *disk) -{ - struct scsi_disk *sdkp = scsi_disk(disk); - - swap(sdkp->zones_wp_offset, sdkp->rev_wp_offset); -} - /* * Call blk_revalidate_disk_zones() if any of the zoned disk properties have * changed that make it necessary to call that function. Called by @@ -831,18 +547,8 @@ int sd_zbc_revalidate_zones(struct scsi_disk *sdkp) struct request_queue *q = disk->queue; u32 zone_blocks = sdkp->early_zone_info.zone_blocks; unsigned int nr_zones = sdkp->early_zone_info.nr_zones; - int ret = 0; unsigned int flags; - - /* - * For all zoned disks, initialize zone append emulation data if not - * already done. - */ - if (sd_is_zoned(sdkp) && !sdkp->zone_wp_update_buf) { - ret = sd_zbc_init_disk(sdkp); - if (ret) - return ret; - } + int ret; /* * There is nothing to do for regular disks, including host-aware disks @@ -851,50 +557,32 @@ int sd_zbc_revalidate_zones(struct scsi_disk *sdkp) if (!blk_queue_is_zoned(q)) return 0; - /* - * Make sure revalidate zones are serialized to ensure exclusive - * updates of the scsi disk data. - */ - mutex_lock(&sdkp->rev_mutex); - if (sdkp->zone_info.zone_blocks == zone_blocks && sdkp->zone_info.nr_zones == nr_zones && disk->nr_zones == nr_zones) - goto unlock; + return 0; - flags = memalloc_noio_save(); sdkp->zone_info.zone_blocks = zone_blocks; sdkp->zone_info.nr_zones = nr_zones; - sdkp->rev_wp_offset = kvcalloc(nr_zones, sizeof(u32), GFP_KERNEL); - if (!sdkp->rev_wp_offset) { - ret = -ENOMEM; - memalloc_noio_restore(flags); - goto unlock; - } blk_queue_chunk_sectors(q, logical_to_sectors(sdkp->device, zone_blocks)); - blk_queue_max_zone_append_sectors(q, - q->limits.max_segments << PAGE_SECTORS_SHIFT); - ret = blk_revalidate_disk_zones(disk, sd_zbc_revalidate_zones_cb); + /* Enable block layer zone append emulation */ + blk_queue_max_zone_append_sectors(q, 0); + flags = memalloc_noio_save(); + ret = blk_revalidate_disk_zones(disk, NULL); memalloc_noio_restore(flags); - kvfree(sdkp->rev_wp_offset); - sdkp->rev_wp_offset = NULL; - if (ret) { sdkp->zone_info = (struct zoned_disk_info){ }; sdkp->capacity = 0; - goto unlock; + return ret; } sd_zbc_print_zones(sdkp); -unlock: - mutex_unlock(&sdkp->rev_mutex); - - return ret; + return 0; } /** @@ -917,10 +605,8 @@ int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 buf[SD_BUF_SIZE]) if (!sd_is_zoned(sdkp)) { /* * Device managed or normal SCSI disk, no special handling - * required. Nevertheless, free the disk zone information in - * case the device type changed. + * required. */ - sd_zbc_free_zone_info(sdkp); return 0; } @@ -941,7 +627,6 @@ int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 buf[SD_BUF_SIZE]) /* The drive satisfies the kernel restrictions: set it up */ blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q); - blk_queue_required_elevator_features(q, ELEVATOR_F_ZBD_SEQ_WRITE); if (sdkp->zones_max_open == U32_MAX) disk_set_max_open_zones(disk, 0); else