From: Kurt Garloff <garloff@xxxxxxx> Subject: Tolerate PQ 3 at LUN 0 for scanning Patch-mainline: References: 158532 Some devices report a peripheral qualifier of 3 for LUN 0; with the original code, we would still try a REPORT_LUNS scan (if SCSI level is >= 3 or if we have the BLIST_REPORTLUNS2 passed in), but NOT any sequential scan. Also, the device at LUN 0 (which is not connected according to the PQ) is not registered with the OS. Unfortunately, SANs exist that are SCSI-2 and do NOT support REPORT_LUNS, but report a unknown device with PQ 3 on LUN 0. We still need to scan them, and most probably we even need BLIST_SPARSELUN (and BLIST_LARGELUN). See the bug reference for an infamous example. This is patch 1/3: If we end up in sequential scan, at least try LUN 1 for devices that reported a PQ of 3 for LUN 0. Also return blacklist flags, even for PQ3 devices. Acked-by: Signed-off-by: Kurt Garloff <garloff@xxxxxxx> Index: linux-2.6.16/drivers/scsi/scsi_scan.c =================================================================== --- linux-2.6.16.orig/drivers/scsi/scsi_scan.c +++ linux-2.6.16/drivers/scsi/scsi_scan.c @@ -860,6 +860,8 @@ static int scsi_probe_and_add_lun(struct if (scsi_probe_lun(sdev, result, result_len, &bflags)) goto out_free_result; + if (bflagsp) + *bflagsp = bflags; /* * result contains valid SCSI INQUIRY data. */ @@ -887,8 +889,6 @@ static int scsi_probe_and_add_lun(struct sdev->lockable = 0; scsi_unlock_floptical(sdev, result); } - if (bflagsp) - *bflagsp = bflags; } out_free_result: @@ -945,11 +945,13 @@ static void scsi_sequential_lun_scan(str sparse_lun = 0; /* - * If not sparse lun and no device attached at LUN 0 do not scan - * any further. - */ + * If LUN0 did respond, but did not have an attachable LUN (PQ=3), + * we do NOT abort the sequential scan yet, let's try one more + * LUN and only abort the scan if we don't find anything there. + * if (!sparse_lun && (lun0_res != SCSI_SCAN_LUN_PRESENT)) return; + */ /* * If less than SCSI_1_CSS, and no special lun scaning, stop -- Kurt Garloff, Head Architect Linux R&D, Novell Inc.
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