SCSI scanning for PQ3 devs
cover SCSI scanning for PQ3 devs
Hi,
solving some SCSI scanning problems that have been reported to us, I came up with the followin patch set.
The trouble is that there are devices that report a LUN with peripheral qualifier on LUN0.
We currently don't handle this well yet:
- Blacklist flags are not used to do special handling if needed.
- If the device does NOT support the REPORT_LUNS scan, we won't see any LUN at all, as we don't even look for LUN 1 then.
Yes, such devices do exist, actually, see PATCH3 ..
The patches do:
- Unconditionally at least look for LUN 1 if LUN 0 was a PQ3 device (but abort scanning there is SPARSELUN is not set and no device can be attached to LUN 1)
- Return the blacklist flags for further usage even if LUN 0 was a PQ3 device.
- Improve the scsi logging information for the the user about the PQ3 issue.
- Introduce a blacklist flag BLIST_ATTACH_PQ3 that allows a PQ3 device to be registered with the OS and thus sg can attach to it. Add two devices to the list.
(One could argue that this should be default, but who knows
what virtual scsi driver will break then ...)
Patches are agains 2.6.16, please consider merging for 2.6.17 or shoot back feedback to me.
Best,
Signature · 1 line
Kurt Garloff, Head Architect Linux R&D, Novell Inc.
PATCH 1/3 Try LUN 1 and use bflags
From: Kurt Garloff <[email protected]>
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:
drivers/scsi/scsi_scan.c +7 -5
@@ -860,6 +860,8 @@ static int scsi_probe_and_add_lun(structif (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
Signature · 1 line
Kurt Garloff, Head Architect Linux R&D, Novell Inc.
Re: [PATCH 1/3] Try LUN 1 and use bflags
Quoted 4 lines · Kurt Garloff
drivers/scsi/scsi_scan.c +0
-0@@ -945,11 +945,13 @@ static void scsi_sequential_lun_scan(str sparse_lun =0 ;/*
drivers/scsi/scsi_scan.c static void scsi_sequential_lun_scan(str · line 954
Quoted 10 lines
drivers/scsi/scsi_scan.c +5
-3-* 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; +*/
Just delete all that, and get rid of lun0_res.
-- Patrick Mansfield
PATCH 1/3 Try LUN 1 and use bflags
In reply to Kurt GarloffHi,
patch redone, incorporating Pat Mansfield's suggestion to remove the lun0_res variable, as it was unused after patching.
From: Kurt Garloff <[email protected]>
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:
drivers/scsi/scsi_scan.c +4 -13
@@ -859,8 +859,10 @@ static int scsi_probe_and_add_lun(structif (scsi_probe_lun (sdev, result, result_len, &bflags)) goto out_free_result; +if (bflagsp) + *bflagsp = bflags;/* * result contains valid SCSI INQUIRY data. */ if ((result[0 ] >>5 ) ==3 ) {
@@ -886,10 +888,8 @@ static int scsi_probe_and_add_lun(structif (bflags &BLIST_KEY ) { sdev->lockable =0 ;scsi_unlock_floptical (sdev, result); } -if (bflagsp) - *bflagsp = bflags; } out_free_result:kfree (result);
@@ -912,9 +912,8 @@ static int scsi_probe_and_add_lun(struct/** * scsi_sequential_lun_scan - sequentially scan a SCSI target * @starget: pointer to target structure to scan * @bflags: black/white list flag for LUN 0 -* @lun0_res: result of scanning LUN 0 * * Description: * Generally, scan from LUN 1 (LUN 0 is assumed to already have been * scanned) to some maximum lun until a LUN is found with no device
@@ -922,10 +921,9 @@ static int scsi_probe_and_add_lun(struct* * Modifies sdevscan->lun. **/ static void scsi_sequential_lun_scan (struct scsi_target *starget, -int bflags,int lun0_res,int scsi_level, -int rescan) +int bflags,int scsi_level,int rescan) {unsigned int sparse_lun, lun, max_dev_lun;struct Scsi_Host *shost =dev_to_shost (starget->dev.parent);
@@ -944,15 +942,8 @@ static void scsi_sequential_lun_scan(str }else sparse_lun =0 ;/* -* If not sparse lun and no device attached at LUN 0 do not scan -* any further. -*/ -if (!sparse_lun && (lun0_res !=SCSI_SCAN_LUN_PRESENT )) -return ; - -/* * If less than SCSI_1_CSS, and no special lun scaning, stop * scanning; this matches 2.4 behaviour, but could just be a bug * (to continue scanning a SCSI_1_CSS device). *
@@ -1363,9 +1354,9 @@ static void __scsi_scan_target(struct de* The REPORT LUN did not scan the target, * do a sequential scan. */ scsi_sequential_lun_scan (starget, bflags, - res, starget->scsi_level, rescan); + starget->scsi_level, rescan); } out_reap:/* now determine if the target has any children at all
Signature · 1 line
Kurt Garloff, Head Architect Linux R&D, Novell Inc.
PATCH 2/3 Better log messages for PQ3 devs
In reply to Kurt GarloffFrom: Kurt Garloff <[email protected]>
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 patch 2/3:
If a PQ3 device is found, log a message that describes the device (INQUIRY DATA and C:B:T:U tuple) and make a suggestion for blacklisting it.
Acked-by:
drivers/scsi/scsi_scan.c +34 -3
@@ -795,8 +795,31 @@ static inline void scsi_destroy_sdev(strtransport_destroy_device (&sdev->sdev_gendev);put_device (&sdev->sdev_gendev); } +/** +* scsi_inq_str - print INQUIRY data from min to max index, +* strip trailing whitespace +* @buf: Output buffer with at least end-first+1 bytes of space +* @inq: Inquiry buffer (input) +* @first: Offset of string into inq +* @end: Index after last character in inq +*/ +static unsigned char *scsi_inq_str (unsigned char * buf,unsigned char *inq, +unsigned first,unsigned end) +{ +unsigned term =0 , idx; +for (idx =0 ; idx+first < end && idx+first < inq[4 ]+5 ; ++idx) { +if (inq[idx+first] >0x20 ) { + buf[idx] = inq[idx+first]; + term = idx+1 ; + }else { + buf[idx] =' ' ; + } + } + buf[term] =0 ; +return buf; +}/** * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it * @starget: pointer to target device structure
@@ -873,11 +896,19 @@ static int scsi_probe_and_add_lun(struct* For disks, this implies that there is no * logical disk configured at sdev->lun, but there * is a target id responding. */ -SCSI_LOG_SCAN_BUS (3 ,printk (KERN_INFO -"scsi scan: peripheral qualifier of 3," -" no device added\n" )); +SCSI_LOG_SCAN_BUS (2 ,printk (KERN_INFO "scsi scan: periph.qual. of 3," +" device %s not added\n" , + sdev->sdev_gendev.bus_id)); +if (lun ==0 ) { +unsigned char vend[9 ], mod[17 ]; +SCSI_LOG_SCAN_BUS (1 ,printk (KERN_INFO "scsi scan: consider passing " +"scsi_mod.dev_flags=%s:%s:0x240 or 0x800240\n" , +scsi_inq_str (vend, result,8 ,16 ), +scsi_inq_str (mod, result,16 ,32 ))); + } + res =SCSI_SCAN_TARGET_PRESENT ; goto out_free_result; }
Signature · 1 line
Kurt Garloff, Head Architect Linux R&D, Novell Inc.
Re: [PATCH 2/3] Better log messages for PQ3 devs
drivers/scsi/scsi_scan.c static int scsi_probe_and_add_lun(struct · line 902
Quoted 7 lines · Kurt Garloff
drivers/scsi/scsi_scan.c +3
-3*/ -SCSI_LOG_SCAN_BUS (3 ,printk (KERN_INFO -"scsi scan: peripheral qualifier of 3," -" no device added\n" )); +SCSI_LOG_SCAN_BUS (2 ,printk (KERN_INFO "scsi scan: periph.qual. of 3," +" device %s not added\n" , + sdev->sdev_gendev.bus_id));
You seem to be suffering from long-line-itis, probably as a result of too much exposure to ia64 code. How about:
SCSI_LOG_SCAN_BUS(2, printk(KERN_INFO "scsi scan: peripheral "
"qualifier of 3, device %s not added\n", sdev->sdev_gendev.bus_id));
drivers/scsi/scsi_scan.c static int scsi_probe_and_add_lun(struct · line 906
Quoted 4 lines
drivers/scsi/scsi_scan.c +4
-0+if (lun ==0 ) { +unsigned char vend[9 ], mod[17 ]; + SCSI_LOG_SCAN_BUS(1, printk(KERN_INFO "scsi scan: consider passing " + "scsi_mod.dev_flags=%s:%s:0x240 or 0x800240\n",
Likewise:
SCSI_LOG_SCAN_BUS(1, printk(KERN_INFO "scsi scan: "
"consider passing scsi_mod.dev_flags=" "%s:%s:0x240 or 0x800240\n",
Quoted 10 lines
drivers/scsi/scsi_scan.c +4
-0+scsi_inq_str (vend, result,8 ,16 ), + scsi_inq_str(mod, result, 16, 32))); + } + res =SCSI_SCAN_TARGET_PRESENT ; goto out_free_result; }Signature · 2 lines
-- Kurt Garloff, Head Architect Linux R&D, Novell Inc.
Re: [PATCH 2/3] Better log messages for PQ3 devs
Hi Matthew,
Quoted 11 lines · Matthew Wilcox
drivers/scsi/scsi_scan.c static int scsi_probe_and_add_lun(struct · line 902
Quoted 7 lines · Kurt Garloff
drivers/scsi/scsi_scan.c +3
-3*/ -SCSI_LOG_SCAN_BUS (3 ,printk (KERN_INFO -"scsi scan: peripheral qualifier of 3," -" no device added\n" )); +SCSI_LOG_SCAN_BUS (2 ,printk (KERN_INFO "scsi scan: periph.qual. of 3," +" device %s not added\n" , + sdev->sdev_gendev.bus_id));You seem to be suffering from long-line-itis, probably as a result of too much exposure to ia64 code. How about:a
Indeed, my terminals are all more than 80 chars wide these days :-) If that's the only concern, I'm happy to address it.
Thx,
Signature · 1 line
Kurt Garloff, Head Architect Linux R&D, Novell Inc.
Re: [PATCH 2/3] Better log messages for PQ3 devs
Quoted 2 lines · Kurt Garloff
Indeed, my terminals are all more than 80 chars wide these days :-) If that's the only concern, I'm happy to address it.
Actually, if you're going to re-roll, please use the sdev_printk() macro instead of printk on the device bus_id.
James
PATCH 2/3 Better log messages for PQ3 devs
In reply to Kurt GarloffHi,
wrapped the lines at column 80 as suggested by Matthew and used sedv_printk as suggested by James.
From: Kurt Garloff <[email protected]>
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 patch 2/3:
If a PQ3 device is found, log a message that describes the device (INQUIRY DATA and C:B:T:U tuple) and make a suggestion for blacklisting it.
Acked-by:
drivers/scsi/scsi_scan.c +35 -3
@@ -795,8 +795,31 @@ static inline void scsi_destroy_sdev(strtransport_destroy_device (&sdev->sdev_gendev);put_device (&sdev->sdev_gendev); } +/** +* scsi_inq_str - print INQUIRY data from min to max index, +* strip trailing whitespace +* @buf: Output buffer with at least end-first+1 bytes of space +* @inq: Inquiry buffer (input) +* @first: Offset of string into inq +* @end: Index after last character in inq +*/ +static unsigned char *scsi_inq_str (unsigned char * buf,unsigned char *inq, +unsigned first,unsigned end) +{ +unsigned term =0 , idx; +for (idx =0 ; idx+first < end && idx+first < inq[4 ]+5 ; ++idx) { +if (inq[idx+first] >0x20 ) { + buf[idx] = inq[idx+first]; + term = idx+1 ; + }else { + buf[idx] =' ' ; + } + } + buf[term] =0 ; +return buf; +}/** * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it * @starget: pointer to target device structure
@@ -875,11 +898,20 @@ static int scsi_probe_and_add_lun(struct* For disks, this implies that there is no * logical disk configured at sdev->lun, but there * is a target id responding. */ -SCSI_LOG_SCAN_BUS (3 ,printk (KERN_INFO -"scsi scan: peripheral qualifier of 3," -" no device added\n" )); +SCSI_LOG_SCAN_BUS (2 ,sdev_printk (KERN_INFO , sdev,"scsi scan:" +" peripheral qualifier of 3, device not" + " added\n")) +if (lun ==0 ) { +unsigned char vend[9 ], mod[17 ]; +SCSI_LOG_SCAN_BUS (1 ,sdev_printk (KERN_INFO , sdev, +"scsi scan: consider passing scsi_mod." +"dev_flags=%s:%s:0x240 or 0x800240\n" , +scsi_inq_str (vend, result,8 ,16 ), +scsi_inq_str (mod, result,16 ,32 ))); + } + res =SCSI_SCAN_TARGET_PRESENT ; goto out_free_result; }
Signature · 1 line
Kurt Garloff, Head Architect Linux R&D, Novell Inc.
PATCH 3/3 BLIST_ATTACH_PQ3 flags
In reply to Kurt GarloffFrom: Kurt Garloff <[email protected]>
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 3/3:
3. Implement the blacklist flag BLIST_ATTACH_PQ3 that makes the scsi scanning code register PQ3 devices and continues scanning; only sg will attach thanks to scsi_bus_match().
Acked-by:
drivers/scsi/scsi_scan.c +1 -1
@@ -888,7 +888,7 @@ static int scsi_probe_and_add_lun(struct/* * result contains valid SCSI INQUIRY data. */ -if ((result[0 ] >>5 ) ==3 ) { +if (((result[0 ] >>5 ) ==3 ) && !(bflags &BLIST_ATTACH_PQ3 )) {/* * For a Peripheral qualifier 3 (011b), the SCSI * spec says: The device server is not capable of
drivers/scsi/scsi_devinfo.c +2 -0
@@ -155,6 +155,8 @@ static struct { {"HITACHI", "DF400", "*", BLIST_SPARSELUN}, {"HITACHI", "DF500", "*", BLIST_SPARSELUN}, {"HITACHI", "DF600", "*", BLIST_SPARSELUN}, + {"HITACHI", "DISK-SUBSYSTEM", "*", BLIST_ATTACH_PQ3 | BLIST_SPARSELUN | BLIST_LARGELUN}, + {"HITACHI", "OPEN-E", "*", BLIST_ATTACH_PQ3 | BLIST_SPARSELUN | BLIST_LARGELUN}, {"HP", "A6189A", NULL, BLIST_SPARSELUN | BLIST_LARGELUN}, /* HP VA7400 */ {"HP", "OPEN-", "*", BLIST_SPARSELUN | BLIST_LARGELUN}, /* HP XP Arrays */ {"HP", "NetRAID-4M", NULL, BLIST_FORCELUN},
include/scsi/scsi_devinfo.h +1 -0
@@ -28,4 +28,5 @@#define BLIST_NO_ULD_ATTACH 0x100000/* device is actually for RAID config */ #define BLIST_SELECT_NO_ATN 0x200000/* select without ATN */ #define BLIST_RETRY_HWERROR 0x400000/* retry HARDWARE_ERROR */ +#define BLIST_ATTACH_PQ3 0x800000/* Scan: Attach to PQ3 devices */ #endif
Signature · 1 line
Kurt Garloff, Head Architect Linux R&D, Novell Inc.
PATCH 3/3 BLIST_ATTACH_PQ3 flags
In reply to Kurt GarloffHi,
rediff, just for completeness. (Unchanged from old patch that still applies with minimal offset.)
From: Kurt Garloff <[email protected]>
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 3/3:
3. Implement the blacklist flag BLIST_ATTACH_PQ3 that makes the scsi scanning code register PQ3 devices and continues scanning; only sg will attach thanks to scsi_bus_match().
Acked-by:
drivers/scsi/scsi_scan.c +1 -1
@@ -887,9 +887,9 @@ static int scsi_probe_and_add_lun(struct *bflagsp = bflags;/* * result contains valid SCSI INQUIRY data. */ -if ((result[0 ] >>5 ) ==3 ) { +if (((result[0 ] >>5 ) ==3 ) && !(bflags &BLIST_ATTACH_PQ3 )) {/* * For a Peripheral qualifier 3 (011b), the SCSI * spec says: The device server is not capable of * supporting a physical device on this logical
drivers/scsi/scsi_devinfo.c +2 -0
@@ -154,8 +154,10 @@ static struct { {"Generic", "USB Storage-SMC", "0207", BLIST_FORCELUN | BLIST_INQUIRY_36}, {"HITACHI", "DF400", "*", BLIST_SPARSELUN}, {"HITACHI", "DF500", "*", BLIST_SPARSELUN}, {"HITACHI", "DF600", "*", BLIST_SPARSELUN}, + {"HITACHI", "DISK-SUBSYSTEM", "*", BLIST_ATTACH_PQ3 | BLIST_SPARSELUN | BLIST_LARGELUN}, + {"HITACHI", "OPEN-E", "*", BLIST_ATTACH_PQ3 | BLIST_SPARSELUN | BLIST_LARGELUN}, {"HP", "A6189A", NULL, BLIST_SPARSELUN | BLIST_LARGELUN}, /* HP VA7400 */ {"HP", "OPEN-", "*", BLIST_SPARSELUN | BLIST_LARGELUN}, /* HP XP Arrays */ {"HP", "NetRAID-4M", NULL, BLIST_FORCELUN}, {"HP", "HSV100", NULL, BLIST_REPORTLUN2 | BLIST_NOSTARTONADD},
include/scsi/scsi_devinfo.h +1 -0
@@ -27,5 +27,6 @@#define BLIST_NOT_LOCKABLE 0x80000/* don't use PREVENT-ALLOW commands */ #define BLIST_NO_ULD_ATTACH 0x100000/* device is actually for RAID config */ #define BLIST_SELECT_NO_ATN 0x200000/* select without ATN */ #define BLIST_RETRY_HWERROR 0x400000/* retry HARDWARE_ERROR */ +#define BLIST_ATTACH_PQ3 0x800000/* Scan: Attach to PQ3 devices */ #endif
Signature · 1 line
Kurt Garloff, Head Architect Linux R&D, Novell Inc.