From 46d1c03c82a717735dddc7a47f321abaccbcec78 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Jan=20H=C3=B6ppner?= Date: Wed, 14 Oct 2015 17:01:04 +0200 Subject: [PATCH] s390/dasd: Improve dasd format code MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit - Make sure a calling function can rely on data in fdata by resetting to its initial values - Move special treatment for track 0 and 1 to dasd_eckd_build_format - Replace dangerous backward goto with a loop logic - Add define for number that specifies the maximum amount of CCWs per request and is used for format_step calculation - Remove unused variable Signed-off-by: Jan Höppner Signed-off-by: Martin Schwidefsky --- drivers/s390/block/dasd_eckd.c | 110 ++++++++++++++++----------------- drivers/s390/block/dasd_int.h | 7 +++ 2 files changed, 59 insertions(+), 58 deletions(-) diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c index 9083247f55a8..8181d6724942 100644 --- a/drivers/s390/block/dasd_eckd.c +++ b/drivers/s390/block/dasd_eckd.c @@ -2349,14 +2349,14 @@ dasd_eckd_build_format(struct dasd_device *base, * when formatting CDL */ if ((intensity & 0x08) && - fdata->start_unit == 0) { + address.cyl == 0 && address.head == 0) { if (i < 3) { ect->kl = 4; ect->dl = sizes_trk0[i] - 4; } } if ((intensity & 0x08) && - fdata->start_unit == 1) { + address.cyl == 0 && address.head == 1) { ect->kl = 44; ect->dl = LABEL_SIZE - 44; } @@ -2392,14 +2392,13 @@ dasd_eckd_format_device(struct dasd_device *base, int enable_pav) { struct dasd_ccw_req *cqr, *n; - struct dasd_block *block; struct dasd_eckd_private *private; struct list_head format_queue; struct dasd_device *device; - int old_stop, format_step; - int step, rc = 0, sleep_rc; + int old_start, old_stop, format_step; + int step, retry; + int rc = 0; - block = base->block; private = (struct dasd_eckd_private *) base->private; /* Sanity checks. */ @@ -2432,68 +2431,63 @@ dasd_eckd_format_device(struct dasd_device *base, INIT_LIST_HEAD(&format_queue); + old_start = fdata->start_unit; old_stop = fdata->stop_unit; - while (fdata->start_unit <= 1) { - fdata->stop_unit = fdata->start_unit; - cqr = dasd_eckd_build_format(base, fdata, enable_pav); - list_add(&cqr->blocklist, &format_queue); - - fdata->stop_unit = old_stop; - fdata->start_unit++; - if (fdata->start_unit > fdata->stop_unit) - goto sleep; - } + format_step = DASD_CQR_MAX_CCW / recs_per_track(&private->rdc_data, 0, + fdata->blksize); + do { + retry = 0; + while (fdata->start_unit <= old_stop) { + step = fdata->stop_unit - fdata->start_unit + 1; + if (step > format_step) { + fdata->stop_unit = + fdata->start_unit + format_step - 1; + } -retry: - format_step = 255 / recs_per_track(&private->rdc_data, 0, - fdata->blksize); - while (fdata->start_unit <= old_stop) { - step = fdata->stop_unit - fdata->start_unit + 1; - if (step > format_step) - fdata->stop_unit = fdata->start_unit + format_step - 1; + cqr = dasd_eckd_build_format(base, fdata, enable_pav); + if (IS_ERR(cqr)) { + rc = PTR_ERR(cqr); + if (rc == -ENOMEM) { + if (list_empty(&format_queue)) + goto out; + /* + * not enough memory available, start + * requests retry after first requests + * were finished + */ + retry = 1; + break; + } + goto out_err; + } + list_add_tail(&cqr->blocklist, &format_queue); - cqr = dasd_eckd_build_format(base, fdata, enable_pav); - if (IS_ERR(cqr)) { - if (PTR_ERR(cqr) == -ENOMEM) { - /* - * not enough memory available - * go to out and start requests - * retry after first requests were finished - */ - fdata->stop_unit = old_stop; - goto sleep; - } else - return PTR_ERR(cqr); + fdata->start_unit = fdata->stop_unit + 1; + fdata->stop_unit = old_stop; } - list_add(&cqr->blocklist, &format_queue); - fdata->start_unit = fdata->stop_unit + 1; - fdata->stop_unit = old_stop; - } + rc = dasd_sleep_on_queue(&format_queue); -sleep: - sleep_rc = dasd_sleep_on_queue(&format_queue); +out_err: + list_for_each_entry_safe(cqr, n, &format_queue, blocklist) { + device = cqr->startdev; + private = (struct dasd_eckd_private *) device->private; + if (cqr->status == DASD_CQR_FAILED) + rc = -EIO; + list_del_init(&cqr->blocklist); + dasd_sfree_request(cqr, device); + private->count--; + } - list_for_each_entry_safe(cqr, n, &format_queue, blocklist) { - device = cqr->startdev; - private = (struct dasd_eckd_private *) device->private; - if (cqr->status == DASD_CQR_FAILED) - rc = -EIO; - list_del_init(&cqr->blocklist); - dasd_sfree_request(cqr, device); - private->count--; - } + if (rc) + goto out; - if (sleep_rc) - return sleep_rc; + } while (retry); - /* - * in case of ENOMEM we need to retry after - * first requests are finished - */ - if (fdata->start_unit <= fdata->stop_unit) - goto retry; +out: + fdata->start_unit = old_start; + fdata->stop_unit = old_stop; return rc; } diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h index 4aed5ed70836..ffd77230dce9 100644 --- a/drivers/s390/block/dasd_int.h +++ b/drivers/s390/block/dasd_int.h @@ -240,6 +240,13 @@ struct dasd_ccw_req { /* Signature for error recovery functions. */ typedef struct dasd_ccw_req *(*dasd_erp_fn_t) (struct dasd_ccw_req *); +/* + * A single CQR can only contain a maximum of 255 CCWs. It is limited by + * the locate record and locate record extended count value which can only hold + * 1 Byte max. + */ +#define DASD_CQR_MAX_CCW 255 + /* * Unique identifier for dasd device. */ -- 2.45.2