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authordave wysochanski <davidw@netapp.com>2006-08-09 14:56:32 -0400
committerJames Bottomley <jejb@mulgrave.il.steeleye.com>2006-08-19 16:37:40 -0400
commit84961f28e9d13a4b193d0c8545f3c060c1890ff3 (patch)
tree11ad36484d5a891a2455d876dfd9cf6fd82f51f3 /drivers
parent8c867b257d159ca04602d7087fa29f846785f9ea (diff)
[SCSI] Don't add scsi_device for devices that return PQ=1, PDT=0x1f
Some targets may return slight variations of PQ and PDT to indicate no LUN mapped. USB UFI setting PDT=0x1f but having reserved bits for PQ is one example, and NetApp targets returning PQ=1 and PDT=0x1f is another. Both instances seem like reasonable responses according to SPC-3 and UFI specs. The current scsi_probe_and_add_lun() code adds a scsi_device for targets that return PQ=1 and PDT=0x1f. This causes LUNs of type "UNKNOWN" to show up in /proc/scsi/scsi when no LUNs are mapped. In addition, subsequent rescans fail to recognize LUNs that may be added on the target, unless preceded by a write to the delete attribute of the "UNKNOWN" LUN. This patch addresses this problem by skipping over the scsi_add_lun() when PQ=1,PDT=0x1f is encountered, and just returns SCSI_SCAN_TARGET_PRESENT. Signed-off-by: Dave Wysochanski <davidw@netapp.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/scsi/scsi_scan.c23
1 files changed, 19 insertions, 4 deletions
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 114e2067dce5..a24d3461fc78 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -893,11 +893,26 @@ static int scsi_probe_and_add_lun(struct scsi_target *starget,
893 } 893 }
894 894
895 /* 895 /*
896 * Non-standard SCSI targets may set the PDT to 0x1f (unknown or 896 * Some targets may set slight variations of PQ and PDT to signal
897 * no device type) instead of using the Peripheral Qualifier to 897 * that no LUN is present, so don't add sdev in these cases.
898 * indicate that no LUN is present. For example, USB UFI does this. 898 * Two specific examples are:
899 * 1) NetApp targets: return PQ=1, PDT=0x1f
900 * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved"
901 * in the UFI 1.0 spec (we cannot rely on reserved bits).
902 *
903 * References:
904 * 1) SCSI SPC-3, pp. 145-146
905 * PQ=1: "A peripheral device having the specified peripheral
906 * device type is not connected to this logical unit. However, the
907 * device server is capable of supporting the specified peripheral
908 * device type on this logical unit."
909 * PDT=0x1f: "Unknown or no device type"
910 * 2) USB UFI 1.0, p. 20
911 * PDT=00h Direct-access device (floppy)
912 * PDT=1Fh none (no FDD connected to the requested logical unit)
899 */ 913 */
900 if (starget->pdt_1f_for_no_lun && (result[0] & 0x1f) == 0x1f) { 914 if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) &&
915 (result[0] & 0x1f) == 0x1f) {
901 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO 916 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
902 "scsi scan: peripheral device type" 917 "scsi scan: peripheral device type"
903 " of 31, no device added\n")); 918 " of 31, no device added\n"));