From 29b8dd9d4274bca6526e4bb8d4f46dec1f4c15c9 Mon Sep 17 00:00:00 2001 From: Stefan Haberland Date: Fri, 18 Jul 2014 14:26:01 +0200 Subject: [PATCH] dasd: fix error recovery for alias devices during format Kernel panic or a hanging device during format if an alias device is set offline or I/O errors occur. Omit the error recovery procedure for alias devices and do retries on the base device with full erp. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky --- drivers/s390/block/dasd.c | 22 ++++++++++++++++------ drivers/s390/block/dasd_eckd.c | 26 +++++++++++++++++--------- drivers/s390/block/dasd_int.h | 3 ++- drivers/s390/block/dasd_ioctl.c | 33 +++++++++++++++++++++++++++------ 4 files changed, 62 insertions(+), 22 deletions(-) diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c index 925b056dc2b3..5df05f26b7d9 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -2307,17 +2307,27 @@ retry: rc = 0; list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) { - if (__dasd_sleep_on_erp(cqr)) { - if (!cqr->status == DASD_CQR_TERMINATED && - !cqr->status == DASD_CQR_NEED_ERP) - break; - rc = 1; + /* + * for alias devices simplify error recovery and + * return to upper layer + */ + if (cqr->startdev != cqr->basedev && + (cqr->status == DASD_CQR_TERMINATED || + cqr->status == DASD_CQR_NEED_ERP)) + return -EAGAIN; + else { + /* normal recovery for basedev IO */ + if (__dasd_sleep_on_erp(cqr)) { + if (!cqr->status == DASD_CQR_TERMINATED && + !cqr->status == DASD_CQR_NEED_ERP) + break; + rc = 1; + } } } if (rc) goto retry; - return 0; } diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c index 39748fda6e1f..e74e5f7b431d 100644 --- a/drivers/s390/block/dasd_eckd.c +++ b/drivers/s390/block/dasd_eckd.c @@ -2061,11 +2061,12 @@ dasd_eckd_fill_geometry(struct dasd_block *block, struct hd_geometry *geo) static struct dasd_ccw_req * dasd_eckd_build_format(struct dasd_device *base, - struct format_data_t *fdata) + struct format_data_t *fdata, + int enable_PAV) { struct dasd_eckd_private *base_priv; struct dasd_eckd_private *start_priv; - struct dasd_device *startdev; + struct dasd_device *startdev = NULL; struct dasd_ccw_req *fcp; struct eckd_count *ect; struct ch_t address; @@ -2079,7 +2080,9 @@ dasd_eckd_build_format(struct dasd_device *base, int nr_tracks; int use_prefix; - startdev = dasd_alias_get_start_dev(base); + if (enable_PAV) + startdev = dasd_alias_get_start_dev(base); + if (!startdev) startdev = base; @@ -2309,6 +2312,7 @@ dasd_eckd_build_format(struct dasd_device *base, fcp->startdev = startdev; fcp->memdev = startdev; + fcp->basedev = base; fcp->retries = 256; fcp->expires = startdev->default_expires * HZ; fcp->buildclk = get_tod_clock(); @@ -2319,7 +2323,8 @@ dasd_eckd_build_format(struct dasd_device *base, static int dasd_eckd_format_device(struct dasd_device *base, - struct format_data_t *fdata) + struct format_data_t *fdata, + int enable_PAV) { struct dasd_ccw_req *cqr, *n; struct dasd_block *block; @@ -2327,7 +2332,7 @@ dasd_eckd_format_device(struct dasd_device *base, struct list_head format_queue; struct dasd_device *device; int old_stop, format_step; - int step, rc = 0; + int step, rc = 0, sleep_rc; block = base->block; private = (struct dasd_eckd_private *) base->private; @@ -2361,11 +2366,11 @@ dasd_eckd_format_device(struct dasd_device *base, } INIT_LIST_HEAD(&format_queue); - old_stop = fdata->stop_unit; + old_stop = fdata->stop_unit; while (fdata->start_unit <= 1) { fdata->stop_unit = fdata->start_unit; - cqr = dasd_eckd_build_format(base, fdata); + cqr = dasd_eckd_build_format(base, fdata, enable_PAV); list_add(&cqr->blocklist, &format_queue); fdata->stop_unit = old_stop; @@ -2383,7 +2388,7 @@ retry: if (step > format_step) fdata->stop_unit = fdata->start_unit + format_step - 1; - cqr = dasd_eckd_build_format(base, fdata); + cqr = dasd_eckd_build_format(base, fdata, enable_PAV); if (IS_ERR(cqr)) { if (PTR_ERR(cqr) == -ENOMEM) { /* @@ -2403,7 +2408,7 @@ retry: } sleep: - dasd_sleep_on_queue(&format_queue); + sleep_rc = dasd_sleep_on_queue(&format_queue); list_for_each_entry_safe(cqr, n, &format_queue, blocklist) { device = cqr->startdev; @@ -2415,6 +2420,9 @@ sleep: private->count--; } + if (sleep_rc) + return sleep_rc; + /* * in case of ENOMEM we need to retry after * first requests are finished diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h index 7a14582dc8a4..2cc188c8203f 100644 --- a/drivers/s390/block/dasd_int.h +++ b/drivers/s390/block/dasd_int.h @@ -175,6 +175,7 @@ struct dasd_ccw_req { struct dasd_block *block; /* the originating block device */ struct dasd_device *memdev; /* the device used to allocate this */ struct dasd_device *startdev; /* device the request is started on */ + struct dasd_device *basedev; /* base device if no block->base */ void *cpaddr; /* address of ccw or tcw */ unsigned char cpmode; /* 0 = cmd mode, 1 = itcw */ char status; /* status of this request */ @@ -321,7 +322,7 @@ struct dasd_discipline { int (*term_IO) (struct dasd_ccw_req *); void (*handle_terminated_request) (struct dasd_ccw_req *); int (*format_device) (struct dasd_device *, - struct format_data_t *); + struct format_data_t *, int enable_PAV); int (*free_cp) (struct dasd_ccw_req *, struct request *); /* diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c index 25a0f2f8b0b9..ad62608e4175 100644 --- a/drivers/s390/block/dasd_ioctl.c +++ b/drivers/s390/block/dasd_ioctl.c @@ -203,7 +203,9 @@ static int dasd_format(struct dasd_block *block, struct format_data_t *fdata) { struct dasd_device *base; - int rc; + int enable_PAV = 1; + int rc, retries; + int start, stop; base = block->base; if (base->discipline->format_device == NULL) @@ -231,11 +233,30 @@ dasd_format(struct dasd_block *block, struct format_data_t *fdata) bdput(bdev); } - rc = base->discipline->format_device(base, fdata); - if (rc) - return rc; - - return 0; + retries = 255; + /* backup start- and endtrack for retries */ + start = fdata->start_unit; + stop = fdata->stop_unit; + do { + rc = base->discipline->format_device(base, fdata, enable_PAV); + if (rc) { + if (rc == -EAGAIN) { + retries--; + /* disable PAV in case of errors */ + enable_PAV = 0; + fdata->start_unit = start; + fdata->stop_unit = stop; + } else + return rc; + } else + /* success */ + break; + } while (retries); + + if (!retries) + return -EIO; + else + return 0; } /* -- 2.20.1