The survival of ide-scsi in 2.6.x

PATCH Willem Riede 4 participants 6 messages Dec 26, 2003 – Jan 3, 2004 1 message not in the archive

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Willem Riede

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2003-12-26 18:13 UTC #0 lore raw

I know that many feel that ide-scsi is useless, and should go away. And you are probably tired of message threads talking about it. Yet I ask respectfully that you hear me out, and give me feedback.

I need ide-scsi to survive. Why? I maintain osst, a driver for OnStream tape drives, which need special handling. These drives exist in SCSI, ATAPI, USB and IEEE1394 versions.

One high-level driver, osst, handles all of them, and that's how it should be, right? For ATAPI, it relies on ide-scsi.

(By the way, ide-tape contains code for the ATAPI version, the DI-30, but that code is old and has serveral known problems - I'd like to see it removed - or at least deprecated - I will do that myself later if people want me to.)

So can we agree to keep ide-scsi? I know it is not desired any more for cd writers. To avoid the problem reports from people who don't realize that and select ide-scsi anyway, we can refuse to attach to a cd-type device (today it just warns). And/or make a new explicit module parameter to tell ide-scsi exactly which drives to attach to.

Today, ide-scsi is buggy, and that needs fixing. The underlying problem is that ide-scsi stands with one leg in the IDE world and one leg in the SCSI world, which creates the challenge to make the IDE error recovery work in sync with, and under the direction of the SCSI error handler.

Example bug reports are [1], [2], [3], [4], [5], and [6].

A recurring problem is scheduling while atomic, see [1], [5], [7]. Linus points bluntly to the problem in [7]. I plead guilty to having introduced that code segment in [8]. I later attempted to improve on the error handling in [9], but that patch was not accepted (and wouldn't have fixed that particular problem).

[6] is different, and has me baffled - what can evoke a page fault in idescsi_transfer_pc?

In the spirit of cleaning up one's own mess, I am working on a new patch, to hopefully alleviate the problems. I've made liberal use of the attachments to the osdl bug reports [1]-[4] created by Mike Christie and a patch from Philip Auld [10], to give credit where it is due. I've also looked at ide-cd to see what it does differently.

Please look at the attachment (looking past the touch-ups that I made while I was at it...). Am I moving in the right direction? Specific changes I need advise on:
1) timer expiry
attachments to [1]-[4] and [10] suggest using it. Is it useful to buy some more time? I don't see the point to wait longer. By returning 0, I let ide_timer_expiry do its thing to handle lost (dma) interrupts. By seeting the PC_TIMEDOUT flag, I tell our end_request function to return DID_TIME_OUT to the scsi system.
2) ide (atapi) abort/error
By providing ide-scsi's own error/abort functions, I defer all errror handling to the scsi error handlers. I have nagging doubts about totally removing ide_do_reset() calls from them though :-(
3) scsi (eh) abort/error
These take much inspiration from Mike Christie's work on [1]-[4] The eh_abort gets called first, and takes an opportunistic approach (if the problem resolves itslf, great). The eh_error pulls the carpet from under the request, and does the ide_do_reset(). I hope I've not introduced any new locking/scheduling issues :-)

I've tested the patched ide-scsi with 2.6.0 - and it works fine. Too good actually, meaning the new error routines have not been adequately exercised. Any hints as to how to simulate errors at the ide subsystem level? Something like Stephen Tweedie's testdrive
[11] perhaps (if applicable to char device), but for 2.6?

Linus states in [7] that ide-scsi needs a maintainer. I haven't seen anyone step forward, so that leads me to believe I may be the only person that depends enough on ide-scsi to be motivated?

If people will have me, I am prepared to take on that responsibility. I am just concerned that I may not have enough of a variety of devices to be able to thoroughly test it (unless the DI-30 is the only one :-)). What do people see as the requirements to be able to maintain ide-scsi?

OK, let me have it... Thanks, Willem Riede.

References:

[1]  http://bugme.osdl.org/show_bug.cgi?id=393
[2]  http://bugme.osdl.org/show_bug.cgi?id=829
[3]  http://bugme.osdl.org/show_bug.cgi?id=1335
[4]  http://bugme.osdl.org/show_bug.cgi?id=1381
[5]  http://marc.theaimsgroup.com/?l=linux-kernel&m=107103475609592&w=2
[6]  http://marc.theaimsgroup.com/?l=linux-scsi&m=105334942001271&w=2
[7]  http://marc.theaimsgroup.com/?l=linux-kernel&m=107150176124047&w=2
[8]  http://marc.theaimsgroup.com/?l=linux-scsi&m=104051080518591&w=2
[9]  http://marc.theaimsgroup.com/?l=linux-scsi&m=104361480527780&w=2

[10] http://marc.theaimsgroup.com/?l=linux-scsi&m=107115248030218&w=2
[11] http://people.redhat.com/sct/patches/testdrive/

ide-scsi.c renamed from ide-scsi.c-l260 +298 ~~-102~~

@@ -29,9 +29,11 @@
  * Ver 0.9   Jul 04 99   Fix a bug in SG_SET_TRANSFORM.
  * Ver 0.91  Jun 10 02   Fix "off by one" error in transforms
  * Ver 0.92  Dec 31 02   Implement new SCSI mid level API
+ * Ver 0.93  Sep 25 03   New error handling implementation.
+ * Ver 0.94  Dec xx 03   Improvements on error handling.
  */
 
-#define IDESCSI_VERSION "0.92"
+#define IDESCSI_VERSION "0.94WR"
 
 #include <linux/module.h>
 #include <linux/config.h>

@@ -54,7 +56,9 @@
 #include "hosts.h"
 #include <scsi/sg.h>
 
-#define IDESCSI_DEBUG_LOG		0
+#define IDESCSI_DEBUG_LOG	0
+#define IDESCSI_DEBUG		KERN_NOTICE
+#define IDESCSI_LOG		KERN_INFO
 
 typedef struct idescsi_pc_s {
 	u8 c[12];				/* Actual packet bytes */

@@ -78,6 +82,7 @@
 #define PC_DMA_IN_PROGRESS		0	/* 1 while DMA in progress */
 #define PC_WRITING			1	/* Data direction */
 #define PC_TRANSFORM			2	/* transform SCSI commands */
+#define PC_TIMEDOUT			3	/* FIXME - WR command timed out */
 #define PC_DMA_OK			4	/* Use DMA */
 
 /*

@@ -270,7 +275,7 @@
 	printk("]\n");
 }
 
-static int idescsi_check_condition(ide_drive_t *drive, struct request *failed_command)
+static int idescsi_check_condition(ide_drive_t *drive, idescsi_pc_t *failed_command)
 {
 	idescsi_scsi_t *scsi = drive_to_idescsi(drive);
 	idescsi_pc_t   *pc;

@@ -298,34 +303,119 @@
 	rq->flags = REQ_SENSE;
 	pc->timeout = jiffies + WAIT_READY;
 	/* NOTE! Save the failed packet command in "rq->buffer" */
-	rq->buffer = (void *) failed_command->special;
-	pc->scsi_cmd = ((idescsi_pc_t *) failed_command->special)->scsi_cmd;
+	rq->buffer = (void *) failed_command;
+	pc->scsi_cmd = failed_command->scsi_cmd;
 	if (test_bit(IDESCSI_LOG_CMD, &scsi->log)) {
-		printk ("ide-scsi: %s: queue cmd = ", drive->name);
+		printk (IDESCSI_LOG "ide-scsi: %s: queue cmd = ", drive->name);
 		hexdump(pc->c, 6);
 	}
 	return ide_do_drive_cmd(drive, rq, ide_preempt);
 }
 
+/* FIXME - WR - code derived from ide_cdrom_error()/abort() -- see ide-cd.c */
+
+/*
+ * Error reporting, in human readable form (luxurious, but a memory hog).
+ */
+byte idescsi_dump_status (ide_drive_t *drive, const char *msg, byte stat)
+{
+	unsigned long flags;
+
+	atapi_status_t status;
+	atapi_error_t error;
+
+	status.all = stat;
+	local_irq_set(flags);
+	printk(KERN_WARNING "ide-scsi: %s: %s: status=0x%02x", drive->name, msg, stat);
+#if IDESCSI_DEBUG_LOG
+	printk(" { ");
+	if (status.b.bsy)
+	       printk("Busy ");
+	else {
+	       if (status.b.drdy)      printk("DriveReady ");
+	       if (status.b.df)        printk("DeviceFault ");
+	       if (status.b.dsc)       printk("SeekComplete ");
+	       if (status.b.drq)       printk("DataRequest ");
+	       if (status.b.corr)      printk("CorrectedError ");
+	       if (status.b.idx)       printk("Index ");
+	       if (status.b.check)     printk("Error ");
+	}
+	printk("}");
+#endif  /* IDESCSI_DEBUG_LOG */
+	printk("\n");
+	if ((status.all & (status.b.bsy|status.b.check)) == status.b.check) {
+	       error.all = HWIF(drive)->INB(IDE_ERROR_REG);
+	       printk(KERN_WARNING "ide-scsi: %s: %s: error=0x%02x", drive->name, msg, error.all);
+#if IDESCSI_DEBUG_LOG
+	       if (error.b.ili)        printk("IllegalLengthIndication ");
+	       if (error.b.eom)        printk("EndOfMedia ");
+	       if (error.b.abrt)       printk("Aborted Command ");
+	       if (error.b.mcr)        printk("MediaChangeRequested ");
+	       if (error.b.sense_key)  printk("LastFailedSense 0x%02x ",
+					   error.b.sense_key);
+#endif  /* IDESCSI_DEBUG_LOG */
+	       printk("\n");
+	}
+	local_irq_restore(flags);
+	return error.all;
+}
+
+ide_startstop_t idescsi_atapi_error (ide_drive_t *drive, const char *msg, byte stat)
+{
+	struct request *rq;
+	byte err;
+
+	err = idescsi_dump_status(drive, msg, stat);
+
+	if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
+		return ide_stopped;
+
+	if (HWIF(drive)->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
+		/* force an abort */
+		HWIF(drive)->OUTB(WIN_IDLEIMMEDIATE,IDE_COMMAND_REG);
+
+	rq->errors++;
+	DRIVER(drive)->end_request(drive, 0, 0);
+	return ide_stopped;
+}
+ 
+ide_startstop_t idescsi_atapi_abort (ide_drive_t *drive, const char *msg)
+{
+	struct request *rq;
+ 
+	if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
+	       return ide_stopped;
+
+#if IDESCSI_DEBUG_LOG
+	printk(IDESCSI_DEBUG "idescsi_atapi_abort called for %lu\n",
+			((idescsi_pc_t *) rq->special)->scsi_cmd->serial_number);
+#endif
+	rq->errors |= ERROR_MAX;
+	DRIVER(drive)->end_request(drive, 0, 0);
+	return ide_stopped;
+}
+
 static int idescsi_end_request (ide_drive_t *drive, int uptodate, int nrsecs)
 {
-	idescsi_scsi_t *scsi = drive_to_idescsi(drive);
-	struct request *rq = HWGROUP(drive)->rq;
-	idescsi_pc_t *pc = (idescsi_pc_t *) rq->special;
-	int log = test_bit(IDESCSI_LOG_CMD, &scsi->log);
+	idescsi_scsi_t   *scsi = drive_to_idescsi(drive);
+	struct request   *rq  = HWGROUP(drive)->rq;
+	idescsi_pc_t     *pc  = (idescsi_pc_t *) rq->special;
+	int               log = test_bit(IDESCSI_LOG_CMD, &scsi->log);
 	struct Scsi_Host *host;
-	u8 *scsi_buf;
-	unsigned long flags;
+	u8               *scsi_buf;
+	unsigned long     flags;
 
 	if (!(rq->flags & (REQ_SPECIAL|REQ_SENSE))) {
 		ide_end_request(drive, uptodate, nrsecs);
 		return 0;
 	}
 	ide_end_drive_cmd (drive, 0, 0);
+
 	if (rq->flags & REQ_SENSE) {
 		idescsi_pc_t *opc = (idescsi_pc_t *) rq->buffer;
 		if (log) {
-			printk ("ide-scsi: %s: wrap up check %lu, rst = ", drive->name, opc->scsi_cmd->serial_number);
+			printk (IDESCSI_LOG "ide-scsi: %s: wrap up check %lu, rst = ",
+					drive->name, opc->scsi_cmd->serial_number);
 			hexdump(pc->buffer,16);
 		}
 		memcpy((void *) opc->scsi_cmd->sense_buffer, pc->buffer, SCSI_SENSE_BUFFERSIZE);

@@ -334,24 +424,38 @@
 		kfree(rq);
 		pc = opc;
 		rq = pc->rq;
-		pc->scsi_cmd->result = (CHECK_CONDITION << 1) | (DID_OK << 16);
-	} else if (rq->errors >= ERROR_MAX) {
-		pc->scsi_cmd->result = DID_ERROR << 16;
+		pc->scsi_cmd->result = (CHECK_CONDITION << 1) |
+					 ((test_bit(PC_TIMEDOUT, &pc->flags)?DID_TIME_OUT:DID_OK) << 16);
+	}
+	else if (test_bit(PC_TIMEDOUT, &pc->flags)) {
+		if (log)
+			printk (IDESCSI_LOG "ide-scsi: %s: timed out for %lu\n",
+					drive->name, pc->scsi_cmd->serial_number);
+		pc->scsi_cmd->result = DID_TIME_OUT << 16;
+	}
+	else if (rq->errors >= ERROR_MAX) {
 		if (log)
-			printk ("ide-scsi: %s: I/O error for %lu\n", drive->name, pc->scsi_cmd->serial_number);
-	} else if (rq->errors) {
+			printk (IDESCSI_LOG "ide-scsi: %s: I/O error for %lu\n",
+					drive->name, pc->scsi_cmd->serial_number);
+		pc->scsi_cmd->result = DID_ERROR << 16;
+	}
+	else if (rq->errors) {
 		if (log)
-			printk ("ide-scsi: %s: check condition for %lu\n", drive->name, pc->scsi_cmd->serial_number);
-		if (!idescsi_check_condition(drive, rq))
+			printk (IDESCSI_LOG "ide-scsi: %s: check condition for %lu\n",
+					drive->name, pc->scsi_cmd->serial_number);
+		if (!idescsi_check_condition(drive, pc))
 			/* we started a request sense, so we'll be back, exit for now */
 			return 0;
 		pc->scsi_cmd->result = (CHECK_CONDITION << 1) | (DID_OK << 16);
-	} else {
+	}
+	else {
 		pc->scsi_cmd->result = DID_OK << 16;
 		idescsi_transform_pc2 (drive, pc);
 		if (log) {
-			printk ("ide-scsi: %s: suc %lu", drive->name, pc->scsi_cmd->serial_number);
-			if (!test_bit(PC_WRITING, &pc->flags) && pc->actually_transferred && pc->actually_transferred <= 1024 && pc->buffer) {
+			printk (IDESCSI_LOG "ide-scsi: %s: success %lu",
+					drive->name, pc->scsi_cmd->serial_number);
+			if (!test_bit(PC_WRITING, &pc->flags) && pc->actually_transferred &&
+			    pc->actually_transferred <= 1024 && pc->buffer) {
 				printk(", rst = ");
 				scsi_buf = pc->scsi_cmd->request_buffer;
 				hexdump(scsi_buf, IDE_MIN(16, pc->scsi_cmd->request_bufflen));

@@ -374,6 +478,19 @@
 	return IDE_MAX(WAIT_CMD, pc->timeout - jiffies);
 }
 
+static int idescsi_expiry(ide_drive_t *drive)
+{
+	idescsi_scsi_t *scsi = drive->driver_data;
+	idescsi_pc_t   *pc   = scsi->pc;
+
+#if IDESCSI_DEBUG_LOG
+	printk(IDESCSI_DEBUG "idescsi_expiry called for %lu at %lu\n", pc->scsi_cmd->serial_number, jiffies);
+#endif
+	set_bit(PC_TIMEDOUT, &pc->flags);
+
+	return 0;					/* we do not want the ide subsystem to retry */
+}
+
 /*
  *	Our interrupt handler.
  */

@@ -390,12 +507,21 @@
 	unsigned int temp;
 
 #if IDESCSI_DEBUG_LOG
-	printk (KERN_INFO "ide-scsi: Reached idescsi_pc_intr interrupt handler\n");
+	printk (IDESCSI_DEBUG "ide-scsi: Reached idescsi_pc_intr interrupt handler\n");
 #endif /* IDESCSI_DEBUG_LOG */
 
+	if (test_bit(PC_TIMEDOUT, &pc->flags)){
+#if IDESCSI_DEBUG_LOG
+		printk(IDESCSI_DEBUG "idescsi_pc_intr: got timed out packet %lu at %lu\n",
+				pc->scsi_cmd->serial_number, jiffies);
+#endif
+		/* end this request now - scsi should retry it*/
+		idescsi_end_request (drive, 1, 0);
+		return ide_stopped;
+	}
 	if (test_and_clear_bit (PC_DMA_IN_PROGRESS, &pc->flags)) {
 #if IDESCSI_DEBUG_LOG
-		printk ("ide-scsi: %s: DMA complete\n", drive->name);
+		printk (IDESCSI_DEBUG "ide-scsi: %s: DMA complete\n", drive->name);
 #endif /* IDESCSI_DEBUG_LOG */
 		pc->actually_transferred=pc->request_transfer;
 		(void) HWIF(drive)->ide_dma_end(drive);

@@ -408,7 +534,8 @@
 	if (!status.b.drq) {
 		/* No more interrupts */
 		if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
-			printk (KERN_INFO "Packet command completed, %d bytes transferred\n", pc->actually_transferred);
+			printk (IDESCSI_LOG "Packet command completed, %d bytes transferred\n",
+					pc->actually_transferred);
 		local_irq_enable();
 		if (status.b.check)
 			rq->errors++;

@@ -442,11 +569,12 @@
 				pc->actually_transferred += temp;
 				pc->current_position += temp;
 				idescsi_discard_data(drive, bcount.all - temp);
-				ide_set_handler(drive, &idescsi_pc_intr, get_timeout(pc), NULL);
+				ide_set_handler(drive, &idescsi_pc_intr, get_timeout(pc), idescsi_expiry);
 				return ide_started;
 			}
 #if IDESCSI_DEBUG_LOG
-			printk (KERN_NOTICE "ide-scsi: The scsi wants to send us more data than expected - allowing transfer\n");
+			printk (IDESCSI_LOG
+				"ide-scsi: The scsi wants to send us more data than expected - allowing transfer\n");
 #endif /* IDESCSI_DEBUG_LOG */
 		}
 	}

@@ -467,7 +595,8 @@
 	pc->actually_transferred += bcount.all;
 	pc->current_position += bcount.all;
 
-	ide_set_handler(drive, &idescsi_pc_intr, get_timeout(pc), NULL);	/* And set the interrupt handler again */
+	/* And set the interrupt handler again */
+	ide_set_handler(drive, &idescsi_pc_intr, get_timeout(pc), idescsi_expiry);
 	return ide_started;
 }

@@ -480,10 +609,10 @@
 
 	if (ide_wait_stat(&startstop,drive,DRQ_STAT,BUSY_STAT,WAIT_READY)) {
 		printk(KERN_ERR "ide-scsi: Strange, packet command "
-			"initiated yet DRQ isn't asserted\n");
+				"initiated yet DRQ isn't asserted\n");
 		return startstop;
 	}
-	ireason.all	= HWIF(drive)->INB(IDE_IREASON_REG);
+	ireason.all = HWIF(drive)->INB(IDE_IREASON_REG);
 	if (!ireason.b.cod || ireason.b.io) {
 		printk(KERN_ERR "ide-scsi: (IO,CoD) != (0,1) while "
 				"issuing a packet command\n");

@@ -492,7 +621,7 @@
 	if (HWGROUP(drive)->handler != NULL)
 		BUG();
 	/* Set the interrupt routine */
-	ide_set_handler(drive, &idescsi_pc_intr, get_timeout(pc), NULL);
+	ide_set_handler(drive, &idescsi_pc_intr, get_timeout(pc), idescsi_expiry);
 	/* Send the actual packet */
 	atapi_output_bytes(drive, scsi->pc->c, 12);
 	if (test_bit (PC_DMA_OK, &pc->flags)) {

@@ -537,12 +666,7 @@
 		set_bit(PC_DMA_OK, &pc->flags);
 
 	if (test_bit(IDESCSI_DRQ_INTERRUPT, &scsi->flags)) {
-		if (HWGROUP(drive)->handler != NULL)
-			BUG();
-		ide_set_handler(drive, &idescsi_transfer_pc,
-				get_timeout(pc), NULL);
-		/* Issue the packet command */
-		HWIF(drive)->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG);
+		ide_execute_command(drive, WIN_PACKETCMD, &idescsi_transfer_pc, get_timeout(pc), idescsi_expiry);
 		return ide_started;
 	} else {
 		/* Issue the packet command */

@@ -557,8 +681,10 @@
 static ide_startstop_t idescsi_do_request (ide_drive_t *drive, struct request *rq, sector_t block)
 {
 #if IDESCSI_DEBUG_LOG
-	printk (KERN_INFO "rq_status: %d, dev: %s, cmd: %x, errors: %d\n",rq->rq_status, rq->rq_disk->disk_name,rq->cmd[0],rq->errors);
-	printk (KERN_INFO "sector: %ld, nr_sectors: %ld, current_nr_sectors: %d\n",rq->sector,rq->nr_sectors,rq->current_nr_sectors);
+	printk (IDESCSI_DEBUG "rq_status: %d, dev: %s, cmd: %x, errors: %d\n",
+			rq->rq_status, rq->rq_disk->disk_name,rq->cmd[0],rq->errors);
+	printk (IDESCSI_DEBUG "sector: %ld, nr_sectors: %ld, current_nr_sectors: %d\n",
+			rq->sector,rq->nr_sectors,rq->current_nr_sectors);
 #endif /* IDESCSI_DEBUG_LOG */
 
 	if (rq->flags & (REQ_SPECIAL|REQ_SENSE)) {

@@ -633,6 +759,8 @@
 	.cleanup		= idescsi_cleanup,
 	.do_request		= idescsi_do_request,
 	.end_request		= idescsi_end_request,
+	.error                  = idescsi_atapi_error,
+	.abort                  = idescsi_atapi_abort,
 	.drives			= LIST_HEAD_INIT(idescsi_driver.drives),
 };

@@ -744,7 +872,8 @@
 		if ((first_bh = bh = idescsi_kmalloc_bio (segments)) == NULL)
 			return NULL;
 #if IDESCSI_DEBUG_LOG
-		printk ("ide-scsi: %s: building DMA table, %d segments, %dkB total\n", drive->name, segments, pc->request_transfer >> 10);
+		printk (IDESCSI_DEBUG "ide-scsi: %s: building DMA table, %d segments, %dkB total\n",
+				drive->name, segments, pc->request_transfer >> 10);
 #endif /* IDESCSI_DEBUG_LOG */
 		while (segments--) {
 			bh->bi_io_vec[0].bv_page = sg->page;

@@ -758,7 +887,8 @@
 		if ((first_bh = bh = idescsi_kmalloc_bio (1)) == NULL)
 			return NULL;
 #if IDESCSI_DEBUG_LOG
-		printk ("ide-scsi: %s: building DMA table for a single buffer (%dkB)\n", drive->name, pc->request_transfer >> 10);
+		printk (IDESCSI_DEBUG "ide-scsi: %s: building DMA table for a single buffer (%dkB)\n",
+				drive->name, pc->request_transfer >> 10);
 #endif /* IDESCSI_DEBUG_LOG */
 		bh->bi_io_vec[0].bv_page = virt_to_page(pc->scsi_cmd->request_buffer);
 		bh->bi_io_vec[0].bv_offset = offset_in_page(pc->scsi_cmd->request_buffer);

@@ -788,16 +918,16 @@
 
 static int idescsi_queue (Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *))
 {
-	idescsi_scsi_t *scsi = scsihost_to_idescsi(cmd->device->host);
-	ide_drive_t *drive = scsi->drive;
-	struct request *rq = NULL;
-	idescsi_pc_t *pc = NULL;
+	idescsi_scsi_t *scsi  = scsihost_to_idescsi(cmd->device->host);
+	ide_drive_t    *drive = scsi->drive;
+	struct request *rq    = NULL;
+	idescsi_pc_t   *pc    = NULL;
 
 	if (!drive) {
 		printk (KERN_ERR "ide-scsi: drive id %d not present\n", cmd->device->id);
 		goto abort;
 	}
-	scsi = drive_to_idescsi(drive);
+//	scsi = drive_to_idescsi(drive);				scsi already initialized above!
 	pc = kmalloc (sizeof (idescsi_pc_t), GFP_ATOMIC);
 	rq = kmalloc (sizeof (struct request), GFP_ATOMIC);
 	if (rq == NULL || pc == NULL) {

@@ -827,10 +957,10 @@
 	idescsi_transform_pc1 (drive, pc);
 
 	if (test_bit(IDESCSI_LOG_CMD, &scsi->log)) {
-		printk ("ide-scsi: %s: que %lu, cmd = ", drive->name, cmd->serial_number);
+		printk (IDESCSI_LOG "ide-scsi: %s: que %lu, cmd = ", drive->name, cmd->serial_number);
 		hexdump(cmd->cmnd, cmd->cmd_len);
 		if (memcmp(pc->c, cmd->cmnd, cmd->cmd_len)) {
-			printk ("ide-scsi: %s: que %lu, tsl = ", drive->name, cmd->serial_number);
+			printk (IDESCSI_LOG "ide-scsi: %s: que %lu, tsl = ", drive->name, cmd->serial_number);
 			hexdump(pc->c, 12);
 		}
 	}

@@ -851,73 +981,139 @@
 	return 1;
 }
 
-static int idescsi_abort (Scsi_Cmnd *cmd)
+static int idescsi_eh_abort (Scsi_Cmnd *cmd)
 {
-	int countdown = 8;
-	unsigned long flags;
-	idescsi_scsi_t *scsi = scsihost_to_idescsi(cmd->device->host);
-	ide_drive_t *drive = scsi->drive;
+	idescsi_scsi_t *scsi  = scsihost_to_idescsi(cmd->device->host);
+	ide_drive_t    *drive = scsi->drive;
+	int		busy;
+	int             ret   = FAILED;
 
-	printk (KERN_ERR "ide-scsi: abort called for %lu\n", cmd->serial_number);
-	while (countdown--) {
-		/* is cmd active?
-		 *  need to lock so this stuff doesn't change under us */
-		spin_lock_irqsave(&ide_lock, flags);
-		if (scsi->pc && scsi->pc->scsi_cmd && 
-				scsi->pc->scsi_cmd->serial_number == cmd->serial_number) {
-			/* yep - let's give it some more time - 
-			 * we can do that, we're in _our_ error kernel thread */
-			spin_unlock_irqrestore(&ide_lock, flags);
-			scsi_sleep(HZ);
-			continue;
-		}
-		/* no, but is it queued in the ide subsystem? */
-		if (elv_queue_empty(drive->queue)) {
-			spin_unlock_irqrestore(&ide_lock, flags);
-			return SUCCESS;
-		}
-		spin_unlock_irqrestore(&ide_lock, flags);
-		schedule_timeout(HZ/10);
+	/* In idescsi_eh_abort we try to gently pry our command from the ide subsystem */
+
+	if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
+		printk (IDESCSI_LOG "ide-scsi: abort called for %lu\n", cmd->serial_number);
+
+	if (!drive) {
+		BUG();
+		goto no_drive;
+	}
+
+	/* First give it some more time, how much is "right" is hard to say :-( */
+
+	busy = ide_wait_not_busy(HWIF(drive), 100);	/* FIXME - uses mdelay which causes latency? */
+	if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
+		printk (IDESCSI_LOG "ide-scsi: drive did%s become ready\n", busy?" not":"");
+
+	spin_lock_irq(&ide_lock);
+
+	/* If there is no pc running we're done (our interrupt took care of it) */
+	if (!scsi->pc) {
+		ret = SUCCESS;
+		goto ide_unlock;
+	}
+
+	/* It's somewhere in flight. Does ide subsystem agree? */
+	if (scsi->pc->scsi_cmd->serial_number == cmd->serial_number && !busy &&
+	    elv_queue_empty(drive->queue) && HWGROUP(drive)->rq != scsi->pc->rq) {
+		/*
+		 * FIXME - not sure this condition can ever occur 
+		 */
+		printk (KERN_ERR "ide-scsi: cmd aborted!\n");
+
+		idescsi_free_bio(scsi->pc->rq->bio);
+		if (scsi->pc->rq->flags & REQ_SENSE)
+			kfree(scsi->pc->buffer);
+		kfree(scsi->pc->rq);
+		kfree(scsi->pc);
+		scsi->pc = NULL;
+
+		ret = SUCCESS;
 	}
-	return FAILED;
+
+ide_unlock:
+	spin_unlock_irq(&ide_lock);
+no_drive:
+	if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
+		printk (IDESCSI_LOG "ide-scsi: abort returns %s\n", ret == SUCCESS?"success":"failed");
+
+	return ret;
 }
 
-static int idescsi_reset (Scsi_Cmnd *cmd)
+static int idescsi_eh_reset (Scsi_Cmnd *cmd)
 {
-	unsigned long flags;
 	struct request *req;
-	idescsi_scsi_t *idescsi = scsihost_to_idescsi(cmd->device->host);
-	ide_drive_t *drive = idescsi->drive;
+	idescsi_scsi_t *scsi  = scsihost_to_idescsi(cmd->device->host);
+	ide_drive_t    *drive = scsi->drive;
+	int             ready = 0;
+	int             ret   = SUCCESS;
+
+	/* In idescsi_eh_reset we forcefully remove the command from the ide subsystem and reset the device. */
+
+	if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
+		printk (IDESCSI_DEBUG "ide-scsi: reset called for %lu\n", cmd->serial_number);
+
+	if (!drive) {
+		BUG();
+		return FAILED;
+	}
 
-	printk (KERN_ERR "ide-scsi: reset called for %lu\n", cmd->serial_number);
-	/* first null the handler for the drive and let any process
-	 * doing IO (on another CPU) run to (partial) completion
-	 * the lock prevents processing new requests */
-	spin_lock_irqsave(&ide_lock, flags);
-	while (HWGROUP(drive)->handler) {
-		HWGROUP(drive)->handler = NULL;
-		schedule_timeout(1);
+	spin_lock_irq(&ide_lock);
+
+	if (!scsi->pc || (req = scsi->pc->rq) != HWGROUP(drive)->rq || !HWGROUP(drive)->handler) {
+		BUG();
+		spin_unlock(&ide_lock);
+		return FAILED;
 	}
+
+	/* kill current request */
+	blkdev_dequeue_request(req);
+	end_that_request_last(req);
+	idescsi_free_bio(req->bio);
+	if (req->flags & REQ_SENSE)
+		kfree(scsi->pc->buffer);
+	kfree(scsi->pc);
+	scsi->pc = NULL;
+	kfree(req);
+
 	/* now nuke the drive queue */
 	while ((req = elv_next_request(drive->queue))) {
 		blkdev_dequeue_request(req);
 		end_that_request_last(req);
 	}
-	/* FIXME - this will probably leak memory */
+
 	HWGROUP(drive)->rq = NULL;
-	if (drive_to_idescsi(drive))
-		drive_to_idescsi(drive)->pc = NULL;
-	spin_unlock_irqrestore(&ide_lock, flags);
-	/* finally, reset the drive (and its partner on the bus...) */
-	ide_do_reset (drive);	
-	return SUCCESS;
+	HWGROUP(drive)->handler = NULL;
+	HWGROUP(drive)->busy = 1;		/* will set this to zero when ide reset finished */
+	spin_unlock_irq(&ide_lock);
+
+	ide_do_reset(drive);
+
+	spin_unlock_irq(cmd->device->host->host_lock);
+
+	/* ide_do_reset starts a polling handler which restarts itself every 50ms until the reset finishes */
+
+	do
+		/* There should be no locks taken at this point */
+		schedule_timeout(HZ/20);
+	while ( HWGROUP(drive)->handler );
+
+	ready = drive_is_ready(drive);
+	HWGROUP(drive)->busy--;
+	if (!ready) {
+		printk (KERN_ERR "ide-scsi: reset failed!\n");
+		ret = FAILED;
+	}
+		
+	spin_lock_irq(cmd->device->host->host_lock);
+
+	return ret;
 }
 
 static int idescsi_bios(struct scsi_device *sdev, struct block_device *bdev,
 		sector_t capacity, int *parm)
 {
-	idescsi_scsi_t *idescsi = scsihost_to_idescsi(sdev->host);
-	ide_drive_t *drive = idescsi->drive;
+	idescsi_scsi_t *scsi = scsihost_to_idescsi(sdev->host);
+	ide_drive_t *drive = scsi->drive;
 
 	if (drive->bios_cyl && drive->bios_head && drive->bios_sect) {
 		parm[0] = drive->bios_head;

@@ -934,8 +1130,8 @@
 	.slave_configure        = idescsi_slave_configure,
 	.ioctl			= idescsi_ioctl,
 	.queuecommand		= idescsi_queue,
-	.eh_abort_handler	= idescsi_abort,
-	.eh_device_reset_handler = idescsi_reset,
+	.eh_abort_handler	= idescsi_eh_abort,
+	.eh_host_reset_handler  = idescsi_eh_reset,
 	.bios_param		= idescsi_bios,
 	.can_queue		= 40,
 	.this_id		= -1,

@@ -949,7 +1145,7 @@
 
 static int idescsi_attach(ide_drive_t *drive)
 {
-	idescsi_scsi_t *idescsi;
+	idescsi_scsi_t *scsi;
 	struct Scsi_Host *host;
 	static int warned;
 	int err;

@@ -968,12 +1164,12 @@
 	host->max_id = 1;
 	host->max_lun = 1;
 	drive->driver_data = host;
-	idescsi = scsihost_to_idescsi(host);
-	idescsi->drive = drive;
+	scsi = scsihost_to_idescsi(host);
+	scsi->drive = drive;
 	err = ide_register_subdriver (drive, &idescsi_driver,
 				      IDE_SUBDRIVER_VERSION);
 	if (!err) {
-		idescsi_setup (drive, idescsi);
+		idescsi_setup (drive, scsi);
 		drive->disk->fops = &idescsi_ops;
 		err = scsi_add_host(host, &drive->gendev);
 		if (!err) {

Wakko Warner

2003-12-27 02:03 UTC #1 lore raw

Quoted 11 lines

I know that many feel that ide-scsi is useless, and should go away. And you are probably tired of message threads talking about it. Yet I ask respectfully that you hear me out, and give me feedback.
So can we agree to keep ide-scsi? I know it is not desired any more for cd writers. To avoid the problem reports from people who don't realize that and select ide-scsi anyway, we can refuse to attach to a cd-type device (today it just warns). And/or make a new explicit module parameter to tell ide-scsi exactly which drives to attach to.

Quoted 5 lines

Today, ide-scsi is buggy, and that needs fixing. The underlying problem is that ide-scsi stands with one leg in the IDE world and one leg in the SCSI world, which creates the challenge to make the IDE error recovery work in sync with, and under the direction of the SCSI error handler.

I have a better idea (This may be sarcasm but maybe not). Why don't we just rip out all ide and scsi subsystems and make one general layer that both physical ide and scsi systems share?

NOTE: I do not have any dealings with the code aspect of IDE and SCSI so I don't know what would be involed (I don't see it happening anyway).

I've never been a fan of IDE, I dislike it completely. I'd prefer to simply buy an ide-scsi hardware converter and make all my drives scsi. But that's just me =)

I did find it funny that an IDE drive in a USB box is a SCSI drive under linux.

Send flames to /dev/null not to the list, I don't want a flame war over this. I will not respond to any flames.

Signature · 1 line

 Lab tests show that use of micro$oft causes cancer in lab animals

Stef van der Made

2003-12-27 12:43 UTC #2 lore raw

In reply to Willem Riede

Willem Riede wrote:

snip

Quoted 4 lines

(By the way, ide-tape contains code for the ATAPI version, the DI-30, but that code is old and has serveral known problems - I'd like to see it removed - or at least deprecated - I will do that myself later if people want me to.)

snip

After some fixing on ide-scsi my DI-30 is now working fine. I don't know of any bugs in it. All works fine for me. Getting rid if ide-scsi might be a good idea but it ain't going to be easy as a lot of programs are using the code.

If you need a tester for the di-30 please feed me the patches and I'll play around with them.

Cheers,

Stef

A message that is not in the archive (sent off-list or not yet received): [email protected]

Stef van der Made

2003-12-28 21:45 UTC #4 lore raw

Hi Willem,

The standard stuff like mt -f /dev/ht0 status etc etc works. But tar doesn't wan't to-do backups anymore both with and witout the patch on a 2.6.0 kernel. I don't have a 2.4.x kernel handy to test if it still works with those kernels and my drive.

What I've done is the following:

bash-2.05# tar -cvb 64 -f /dev/ht0 /
tar: Removing leading `/' from absolute path names in the archive

lost+found/
usr/
usr/X11
usr/adm
usr/bin/
usr/bin/w
usr/bin/ar
tar: Cannot write to /dev/ht0: Invalid argument
tar: Error is not recoverable: exiting now

It looks as if the backup starts but it almost immediatly ends after the drive does some spinning and reading and or writing.

Cheers

Stef

Quoted 42 lines · Willem Riede

Quoted 6 lines · Stef van der Made
Willem Riede wrote:
snip
Quoted 9 lines
Quoted 4 lines
(By the way, ide-tape contains code for the ATAPI version, the DI-30, but that code is old and has serveral known problems - I'd like to see it removed - or at least deprecated - I will do that myself later if people want me to.)
snip
After some fixing on ide-scsi my DI-30 is now working fine. I don't know of any bugs in it. All works fine for me.
If your system ever loses an interrupt form the DI-30 you'll find out :-)
Quoted 4 lines
Getting rid if ide-scsi might
be a good idea but it ain't going to be easy as a lot of programs are using the code.
I was actually trying to save ide-scsi, as we need it for the DI-30 + osst.
Quoted 3 lines
If you need a tester for the di-30 please feed me the patches and I'll play around with them.
Well, you could try the patch in the oiginal mail, and there is a new version of osst on osst.sourceforge.net that you could test.
Thnaks, Willem Riede.

Bill Davidsen

2004-01-03 14:11 UTC #5 lore raw

Quoted 20 lines · Stef van der Made

Hi Willem,
The standard stuff like mt -f /dev/ht0 status etc etc works. But tar doesn't wan't to-do backups anymore both with and witout the patch on a 2.6.0 kernel. I don't have a 2.4.x kernel handy to test if it still works with those kernels and my drive.
What I've done is the following:
bash-2.05# tar -cvb 64 -f /dev/ht0 /
tar: Removing leading `/' from absolute path names in the archive
lost+found/
usr/
usr/X11
usr/adm
usr/bin/
usr/bin/w
usr/bin/ar
tar: Cannot write to /dev/ht0: Invalid argument
tar: Error is not recoverable: exiting now

Quoted 1 line

It looks as if the backup starts but it almost immediatly ends after the drive does some spinning and reading and or writing.

It sounds stupid, but you did set the tape block size as appropriate, didn't you? I've seen similar with incorrect block size writes in the past, but I don't have the correct hardware home to try it.

Signature · 3 lines

bill davidsen <[email protected]>
  CTO TMR Associates, Inc
  Doing interesting things with small computers since 1979

Bill Davidsen

2004-01-03 14:18 UTC #6 lore raw

In reply to Willem Riede

Quoted 14 lines · Willem Riede

I know that many feel that ide-scsi is useless, and should go away. And you are probably tired of message threads talking about it. Yet I ask respectfully that you hear me out, and give me feedback.
I need ide-scsi to survive. Why? I maintain osst, a driver for OnStream tape drives, which need special handling. These drives exist in SCSI, ATAPI, USB and IEEE1394 versions.
In the spirit of cleaning up one's own mess, I am working on a new
patch, to hopefully alleviate the problems. I've made liberal use of the attachments to the osdl bug reports [1]-[4] created by Mike Christie and a patch from Philip Auld [10], to give credit where it is due. I've also looked at ide-cd to see what it does differently.

Quoted 6 lines

Linus states in [7] that ide-scsi needs a maintainer. I haven't seen anyone step forward, so that leads me to believe I may be the only person that depends enough on ide-scsi to be motivated?
If people will have me, I am prepared to take on that responsibility. I am just concerned that I may not have enough of a variety of devices to be able to thoroughly test it (unless the DI-30 is the only one :-)). What do people see as the requirements to be able to maintain ide-scsi?

Sounds good to me, here we have someone who has both the need, the ambition, and the time to do this. Users of tape and MO still have need for ide-scsi, and would be happy to help test at least.

Signature · 3 lines

bill davidsen <[email protected]>
  CTO TMR Associates, Inc
  Doing interesting things with small computers since 1979