mirrors/scst
1
0
Fork 0
mirror of https://github.com/SCST-project/scst.git synced 2026-05-17 18:51:27 +00:00
Code Issues Packages Projects Releases Wiki Activity

qla2x00t: Copy entire SCST sense buffer to q2x ctio

Browse Source 
There seems to be a bug in passing sense information to QLA HBAs, where 
the last 2 bytes of the sense data (ASC, ASCQ) are not copied to the low 
level sense buffer.
We encountered this in ESX, which relies on these 2 bytes to parse the 
MISCOMPARE sense code (0xE1, 0x1D, 0x00).
Bellow is a simple test to recreate this issue, but during vMotion 
operations (where VMs are moved from one host to another), this may 
cause the operation to fail leaving the VM in an inconsistent state.

The test I ran to verify that we are indeed missing the bytes is the 
following:
1. Create a SCST based device
2. Expose the device to 2 ESX hosts
3. Format the device as VMFS5, create a test directory
4. From both hosts, I start writing to this directory (no VMs involved, 
just write normal files)

At this stage, both ESX hosts try to take access to the directory.
The VMFS filesystem contains a per-directory lock which is managed by 
COMPARE AND WRITE command.
Each ESX will attempt to change the VMFS lock location from unlocked to 
locked to create the new file.

Obviously there are bound to be failures (which are equivalent to 
programming locking conflicts), these are reported by the MISCOMPARE 
sense code.
Upon these MISCOMPARE errors, the host will re-try taking the lock until 
it succeeds, and will then proceed to perform the write operation on the 
directory.

Due to the bug in copying the sense buffer from the SCST core to the QLA 
ctio, instead of the full sense code, only the key (0xE) is sent, and 
ESX does not know how to handle it resulting in IO error.

Here are the errors as they appear on the command line:
/vmfs/volumes/54a297c4-ca5af1cc-7f94-002219d20f28/ats_test # 
./open_close_test-esx2.sh
./open_close_test-esx2.sh: line 8: can't create 
ats_fileoptest-esx2_1.txt: Input/output error
./open_close_test-esx2.sh: line 8: can't create 
ats_fileoptest-esx2_21.txt: Input/output error
./open_close_test-esx2.sh: line 8: can't create 
ats_fileoptest-esx2_110.txt: Input/output error
./open_close_test-esx2.sh: line 8: can't create 
ats_fileoptest-esx2_111.txt: Input/output error

In the /var/log/vmkernel.log, we can see that the sense information is 
missing (0xE, 0x0, 0x0) instead of (0xE, 0x1D, 0x0).
2014-12-30T12:13:20.714Z cpu6:33519)ScsiDeviceIO: 2338: 
Cmd(0x412e84f957c0) 0x89, CmdSN 0x234d from world 519051 to dev 
"eui.0024f400d5020007" failed H:0x0 D:0x2 P:0x0 Valid sense data: 0xe 0x0 0x0.
2014-12-30T12:13:20.766Z cpu6:33519)ScsiDeviceIO: 2338: 
Cmd(0x412e84f91d00) 0x89, CmdSN 0x2350 from world 519051 to dev 
"eui.0024f400d5020007" failed H:0x0 D:0x2 P:0x0 Valid sense data: 0xe 0x0 0x0.
2014-12-30T12:13:20.766Z cpu6:33519)ScsiDeviceIO: 2338: 
Cmd(0x412e80449fc0) 0x89, CmdSN 0x234f from world 519051 to dev 
"eui.0024f400d5020007" failed H:0x0 D:0x2 P:0x0 Valid sense data: 0xe 0x0 0x0.

This patch fixes this issue, the test will run without a problem with the
fix (no IO errors, all the files are properly written to the directory).

Signed-off-by: Shahar Salzman <shahar.salzman@kaminario.com>
Reviewed-by: Eran Mann <eran.mann@kaminario.com>
[bvanassche: simplified implementation]
Signed-off-by: Bart Van Assche <bvanassche@acm.org>


git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5965 d57e44dd-8a1f-0410-8b47-8ef2f437770f
This commit is contained in:
Bart Van Assche
2015-01-13 08:55:46 +00:00
parent efff5e2a20
commit fec8d2459c
1 changed files with 27 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

42
qla2x00t/qla2x00-target/qla2x00t.c
View File

@@ -2679,6 +2679,31 @@ out_unlock_free_unmap:
goto out;
}
/*
* Convert sense buffer (byte array) to little endian format as required by
* qla24xx firmware.
*/
static void q24_copy_sense_buffer_to_ctio(ctio7_status1_entry_t *ctio,
uint8_t *sense_buf, unsigned int sense_buf_len)
{
uint32_t *src = (void *)sense_buf;
uint32_t *end = (void *)sense_buf + sense_buf_len;
uint8_t *p;
__be32 *dst = (void *)ctio->sense_data;
/*
* The sense buffer allocated by scst_alloc_sense() is zero-filled and
* has a length that is a multiple of four. This means that it is safe
* to access the bytes after the end of the sense buffer up to a
* boundary that is a multiple of four.
*/
for (p = (uint8_t *)end; ((uintptr_t)p & 3) != 0; p++)
WARN_ONCE(*p != 0, "sense_buf[%zd] = %d\n", p - sense_buf, *p);
for ( ; src < end; src++)
*dst++ = cpu_to_be32(*src);
}
static inline int q2t_need_explicit_conf(scsi_qla_host_t *ha,
struct q2t_cmd *cmd, int sending_sense)
{
@@ -2914,7 +2939,6 @@ static void q24_init_ctio_ret_entry(ctio7_status0_entry_t *ctio,
ctio->residual = cpu_to_le32(prm->residual);
ctio->scsi_status = cpu_to_le16(prm->rq_result);
if (scst_sense_valid(prm->sense_buffer)) {
int i;
ctio1 = (ctio7_status1_entry_t *)ctio;
if (q2t_need_explicit_conf(prm->tgt->ha, prm->cmd, 1)) {
ctio1->flags |= cpu_to_le16(
@@ -2925,20 +2949,8 @@ static void q24_init_ctio_ret_entry(ctio7_status0_entry_t *ctio,
ctio1->flags |= cpu_to_le16(CTIO7_FLAGS_STATUS_MODE_1);
ctio1->scsi_status |= cpu_to_le16(SS_SENSE_LEN_VALID);
ctio1->sense_length = cpu_to_le16(prm->sense_buffer_len);
for (i = 0; i < prm->sense_buffer_len/4; i++)
((uint32_t *)ctio1->sense_data)[i] =
cpu_to_be32(((uint32_t *)prm->sense_buffer)[i]);
#if 0
if (unlikely((prm->sense_buffer_len % 4) != 0)) {
static int q;
if (q < 10) {
PRINT_INFO("qla2x00t(%ld): %d bytes of sense "
"lost", prm->tgt->ha->instance,
prm->sense_buffer_len % 4);
q++;
}
}
#endif
q24_copy_sense_buffer_to_ctio(ctio1, prm->sense_buffer,
prm->sense_buffer_len);
} else {
ctio1 = (ctio7_status1_entry_t *)ctio;
ctio1->flags &= ~cpu_to_le16(CTIO7_FLAGS_STATUS_MODE_0);