kern/173291: mfi corrupts JBOD disks >2TB due to LBA overflow
Steven Hartland
steven.hartland at multiplay.co.uk
Fri Nov 2 10:10:00 UTC 2012
>Number: 173291
>Category: kern
>Synopsis: mfi corrupts JBOD disks >2TB due to LBA overflow
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Fri Nov 02 10:10:00 UTC 2012
>Closed-Date:
>Last-Modified:
>Originator: Steven Hartland
>Release: 8.3-RELEASE
>Organization:
Multiplay
>Environment:
FreeBSD dev 8.3-RELEASE-p4 FreeBSD 8.3-RELEASE-p4 #22: Mon Sep 17 17:18:32 UTC 2012 root at dev:/usr/obj/usr/src/sys/MULTIPLAY amd64
>Description:
The current code in mfi for SYSPD aka JBOD disks corrupts data due to an LBA overflow.
This is caused because for the syspd case mfi always uses READ 10 / WRITE 10 requests for accessing the device, so a write over 2^32 wraps and starts writing at the beginning of the disk.
>How-To-Repeat:
1. zero out block 1 on the disk
dd if=/dev/zero bs=512 count=1 of=/dev/mfisyspd0
1+0 records in
1+0 records out
512 bytes transferred in 0.000728 secs (703171 bytes/sec)
2. confirm the first block is zeros
dd if=/dev/mfisyspd0 bs=512 count=1 | hexdump -C
1+0 records in
1+0 records out
512 bytes transferred in 0.000250 secs (2047172 bytes/sec)
00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000200
3. write 1 block random after the 2TB boundary
dd if=/dev/random bs=512 count=1 of=/dev/mfisyspd0 oseek=4294967296
1+0 records in
1+0 records out
512 bytes transferred in 0.000717 secs (714162 bytes/sec)
4. first block of the disk now contains random data
dd if=/dev/mfisyspd0 bs=512 count=8 | hexdump -C
00000000 9c d1 d2 1d 9f 2c fc 30 ab 09 7a f7 64 16 2a 58 |.....,.0..z.d.*X|
00000010 18 27 9d 1f ae 4d 27 53 1a 50 e7 c1 b1 3a 9b e4 |.'...M'S.P...:..|
00000020 c3 7c d0 25 83 e2 bd 85 33 f2 33 8e 71 55 70 7c |.|.%....3.3.qUp||
00000030
>Fix:
Apply the attached patch
Patch attached with submission follows:
Adds support for READ/WRITE 6, 10, 12 & 16 to syspd aka JBOD disks
based on sys/cam/scsi_all.c scsi_read_write.
Prior to this disks greater than 2^32 sectors would result in data
corrupt when sectors greater than 2^32 where accessed.
It may be a good idea at some point to extract the CDB creation logic
from scsi_read_write so it can be directly used in cases like this.
--- sys/dev/mfi/mfi.c.orig 2012-11-02 00:44:20.799257878 +0000
+++ sys/dev/mfi/mfi.c 2012-11-02 00:48:14.480092782 +0000
@@ -78,6 +78,7 @@
#include <machine/bus.h>
#include <machine/resource.h>
+#include <cam/scsi/scsi_all.h>
#include <dev/mfi/mfireg.h>
#include <dev/mfi/mfi_ioctl.h>
#include <dev/mfi/mfivar.h>
@@ -105,6 +106,8 @@
static struct mfi_command * mfi_bio_command(struct mfi_softc *);
static void mfi_bio_complete(struct mfi_command *);
static struct mfi_command *mfi_build_ldio(struct mfi_softc *,struct bio*);
+static int mfi_build_syspd_cdb(struct mfi_pass_frame *pass, uint32_t block_count,
+ uint64_t lba, uint8_t byte2, int readop);
static struct mfi_command *mfi_build_syspdio(struct mfi_softc *,struct bio*);
static int mfi_send_frame(struct mfi_softc *, struct mfi_command *);
static int mfi_abort(struct mfi_softc *, struct mfi_command *);
@@ -1988,13 +1991,78 @@
mfi_enqueue_bio(sc, bio);
return cm;
}
+
+static int
+mfi_build_syspd_cdb(struct mfi_pass_frame *pass, uint32_t block_count,
+ uint64_t lba, uint8_t byte2, int readop)
+{
+ int cdb_len;
+
+ if (((lba & 0x1fffff) == lba)
+ && ((block_count & 0xff) == block_count)
+ && (byte2 == 0)) {
+ /* We can fit in a 6 byte cdb */
+ struct scsi_rw_6 *scsi_cmd;
+
+ scsi_cmd = (struct scsi_rw_6 *)&pass->cdb;
+ scsi_cmd->opcode = readop ? READ_6 : WRITE_6;
+ scsi_ulto3b(lba, scsi_cmd->addr);
+ scsi_cmd->length = block_count & 0xff;
+ scsi_cmd->control = 0;
+ cdb_len = sizeof(*scsi_cmd);
+ } else if (((block_count & 0xffff) == block_count) && ((lba & 0xffffffff) == lba)) {
+ /* Need a 10 byte CDB */
+ struct scsi_rw_10 *scsi_cmd;
+
+ scsi_cmd = (struct scsi_rw_10 *)&pass->cdb;
+ scsi_cmd->opcode = readop ? READ_10 : WRITE_10;
+ scsi_cmd->byte2 = byte2;
+ scsi_ulto4b(lba, scsi_cmd->addr);
+ scsi_cmd->reserved = 0;
+ scsi_ulto2b(block_count, scsi_cmd->length);
+ scsi_cmd->control = 0;
+ cdb_len = sizeof(*scsi_cmd);
+ } else if (((block_count & 0xffffffff) == block_count) &&
+ ((lba & 0xffffffff) == lba)) {
+ /* Block count is too big for 10 byte CDB use a 12 byte CDB */
+ struct scsi_rw_12 *scsi_cmd;
+
+ scsi_cmd = (struct scsi_rw_12 *)&pass->cdb;
+ scsi_cmd->opcode = readop ? READ_12 : WRITE_12;
+ scsi_cmd->byte2 = byte2;
+ scsi_ulto4b(lba, scsi_cmd->addr);
+ scsi_cmd->reserved = 0;
+ scsi_ulto4b(block_count, scsi_cmd->length);
+ scsi_cmd->control = 0;
+ cdb_len = sizeof(*scsi_cmd);
+ } else {
+ /*
+ * 16 byte CDB. We'll only get here if the LBA is larger
+ * than 2^32
+ */
+ struct scsi_rw_16 *scsi_cmd;
+
+ scsi_cmd = (struct scsi_rw_16 *)&pass->cdb;
+ scsi_cmd->opcode = readop ? READ_16 : WRITE_16;
+ scsi_cmd->byte2 = byte2;
+ scsi_u64to8b(lba, scsi_cmd->addr);
+ scsi_cmd->reserved = 0;
+ scsi_ulto4b(block_count, scsi_cmd->length);
+ scsi_cmd->control = 0;
+ cdb_len = sizeof(*scsi_cmd);
+ }
+
+ return cdb_len;
+}
+
static struct mfi_command *
mfi_build_syspdio(struct mfi_softc *sc, struct bio *bio)
{
struct mfi_command *cm;
struct mfi_pass_frame *pass;
- int flags = 0, blkcount = 0;
- uint32_t context = 0;
+ int flags = 0;
+ uint8_t cdb_len;
+ uint32_t block_count, context = 0;
if ((cm = mfi_dequeue_free(sc)) == NULL)
return (NULL);
@@ -2008,35 +2076,29 @@
pass->header.cmd = MFI_CMD_PD_SCSI_IO;
switch (bio->bio_cmd & 0x03) {
case BIO_READ:
-#define SCSI_READ 0x28
- pass->cdb[0] = SCSI_READ;
flags = MFI_CMD_DATAIN;
break;
case BIO_WRITE:
-#define SCSI_WRITE 0x2a
- pass->cdb[0] = SCSI_WRITE;
flags = MFI_CMD_DATAOUT;
break;
default:
- panic("Invalid bio command");
+ /* TODO: what about BIO_DELETE??? */
+ panic("Unsupported bio command");
}
/* Cheat with the sector length to avoid a non-constant division */
- blkcount = (bio->bio_bcount + MFI_SECTOR_LEN - 1) / MFI_SECTOR_LEN;
+ block_count = (bio->bio_bcount + MFI_SECTOR_LEN - 1) / MFI_SECTOR_LEN;
/* Fill the LBA and Transfer length in CDB */
- pass->cdb[2] = (bio->bio_pblkno & 0xff000000) >> 24;
- pass->cdb[3] = (bio->bio_pblkno & 0x00ff0000) >> 16;
- pass->cdb[4] = (bio->bio_pblkno & 0x0000ff00) >> 8;
- pass->cdb[5] = bio->bio_pblkno & 0x000000ff;
- pass->cdb[7] = (blkcount & 0xff00) >> 8;
- pass->cdb[8] = (blkcount & 0x00ff);
+ cdb_len = mfi_build_syspd_cdb(pass, block_count, bio->bio_pblkno, 0,
+ flags == MFI_CMD_DATAIN);
+
pass->header.target_id = (uintptr_t)bio->bio_driver1;
pass->header.timeout = 0;
pass->header.flags = 0;
pass->header.scsi_status = 0;
pass->header.sense_len = MFI_SENSE_LEN;
pass->header.data_len = bio->bio_bcount;
- pass->header.cdb_len = 10;
+ pass->header.cdb_len = cdb_len;
pass->sense_addr_lo = (uint32_t)cm->cm_sense_busaddr;
pass->sense_addr_hi = (uint32_t)((uint64_t)cm->cm_sense_busaddr >> 32);
cm->cm_complete = mfi_bio_complete;
@@ -2075,7 +2137,8 @@
flags = MFI_CMD_DATAOUT;
break;
default:
- panic("Invalid bio command");
+ /* TODO: what about BIO_DELETE??? */
+ panic("Unsupported bio command");
}
/* Cheat with the sector length to avoid a non-constant division */
@@ -2466,7 +2529,7 @@
struct mfi_command *cm;
struct mfi_pass_frame *pass;
int error;
- int blkcount = 0;
+ uint32_t blkcount;
if ((cm = mfi_dequeue_free(sc)) == NULL)
return (EBUSY);
@@ -2474,21 +2537,14 @@
pass = &cm->cm_frame->pass;
bzero(pass->cdb, 16);
pass->header.cmd = MFI_CMD_PD_SCSI_IO;
- pass->cdb[0] = SCSI_WRITE;
- pass->cdb[2] = (lba & 0xff000000) >> 24;
- pass->cdb[3] = (lba & 0x00ff0000) >> 16;
- pass->cdb[4] = (lba & 0x0000ff00) >> 8;
- pass->cdb[5] = (lba & 0x000000ff);
blkcount = (len + MFI_SECTOR_LEN - 1) / MFI_SECTOR_LEN;
- pass->cdb[7] = (blkcount & 0xff00) >> 8;
- pass->cdb[8] = (blkcount & 0x00ff);
pass->header.target_id = id;
pass->header.timeout = 0;
pass->header.flags = 0;
pass->header.scsi_status = 0;
pass->header.sense_len = MFI_SENSE_LEN;
pass->header.data_len = len;
- pass->header.cdb_len = 10;
+ pass->header.cdb_len = mfi_build_syspd_cdb(pass, blkcount, lba, 0, 0);
pass->sense_addr_lo = (uint32_t)cm->cm_sense_busaddr;
pass->sense_addr_hi = (uint32_t)((uint64_t)cm->cm_sense_busaddr >> 32);
cm->cm_data = virt;
>Release-Note:
>Audit-Trail:
>Unformatted:
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