On Tue, Jul 03, 2018 at 09:57:06AM +0200, Martin Wilck wrote: > Use similar logic as the kernel for retrying ALUA commands to > avoid misinterpreting temporary failures as fatal errors. > > Signed-off-by: Martin Wilck <[email protected]> Reviewed-by: Benjamin Marzinski <[email protected]> > --- > libmultipath/prioritizers/alua_rtpg.c | 59 +++++++++++++++++++++++---- > 1 file changed, 50 insertions(+), 9 deletions(-) > > diff --git a/libmultipath/prioritizers/alua_rtpg.c > b/libmultipath/prioritizers/alua_rtpg.c > index ce405b55..34b5f3ce 100644 > --- a/libmultipath/prioritizers/alua_rtpg.c > +++ b/libmultipath/prioritizers/alua_rtpg.c > @@ -69,10 +69,20 @@ print_hex(unsigned char *p, unsigned long len) > #define SCSI_COMMAND_TERMINATED 0x22 > #define SG_ERR_DRIVER_SENSE 0x08 > #define RECOVERED_ERROR 0x01 > +#define NOT_READY 0x2 > +#define UNIT_ATTENTION 0x6 > + > +enum scsi_disposition { > + SCSI_GOOD = 0, > + SCSI_ERROR, > + SCSI_RETRY, > +}; > > static int > -scsi_error(struct sg_io_hdr *hdr) > +scsi_error(struct sg_io_hdr *hdr, int opcode) > { > + int sense_key, asc, ascq; > + > /* Treat SG_ERR here to get rid of sg_err.[ch] */ > hdr->status &= 0x7e; > > @@ -81,29 +91,44 @@ scsi_error(struct sg_io_hdr *hdr) > (hdr->host_status == 0) && > (hdr->driver_status == 0) > ) { > - return 0; > + return SCSI_GOOD; > } > > + sense_key = asc = ascq = -1; > if ( > (hdr->status == SCSI_CHECK_CONDITION) || > (hdr->status == SCSI_COMMAND_TERMINATED) || > ((hdr->driver_status & 0xf) == SG_ERR_DRIVER_SENSE) > ) { > if (hdr->sbp && (hdr->sb_len_wr > 2)) { > - int sense_key; > unsigned char * sense_buffer = hdr->sbp; > > - if (sense_buffer[0] & 0x2) > + if (sense_buffer[0] & 0x2) { > sense_key = sense_buffer[1] & 0xf; > - else > + if (hdr->sb_len_wr > 3) > + asc = sense_buffer[2]; > + if (hdr->sb_len_wr > 4) > + ascq = sense_buffer[3]; > + } else { > sense_key = sense_buffer[2] & 0xf; > + if (hdr->sb_len_wr > 13) > + asc = sense_buffer[12]; > + if (hdr->sb_len_wr > 14) > + ascq = sense_buffer[13]; > + } > > if (sense_key == RECOVERED_ERROR) > - return 0; > + return SCSI_GOOD; > } > } > > - return 1; > + PRINT_DEBUG("alua: SCSI error for command %02x: status %02x, sense > %02x/%02x/%02x", > + opcode, hdr->status, sense_key, asc, ascq); > + > + if (sense_key == UNIT_ATTENTION || sense_key == NOT_READY) > + return SCSI_RETRY; > + else > + return SCSI_ERROR; > } > > /* > @@ -116,7 +141,9 @@ do_inquiry(int fd, int evpd, unsigned int codepage, > struct inquiry_command cmd; > struct sg_io_hdr hdr; > unsigned char sense[SENSE_BUFF_LEN]; > + int rc, retry_count = 3; > > +retry: > memset(&cmd, 0, sizeof(cmd)); > cmd.op = OPERATION_CODE_INQUIRY; > if (evpd) { > @@ -142,9 +169,15 @@ do_inquiry(int fd, int evpd, unsigned int codepage, > return -RTPG_INQUIRY_FAILED; > } > > - if (scsi_error(&hdr)) { > + rc = scsi_error(&hdr, OPERATION_CODE_INQUIRY); > + if (rc == SCSI_ERROR) { > PRINT_DEBUG("do_inquiry: SCSI error!"); > return -RTPG_INQUIRY_FAILED; > + } else if (rc == SCSI_RETRY) { > + if (--retry_count >= 0) > + goto retry; > + PRINT_DEBUG("do_inquiry: retries exhausted!"); > + return -RTPG_INQUIRY_FAILED; > } > PRINT_HEX((unsigned char *) resp, resplen); > > @@ -265,7 +298,9 @@ do_rtpg(int fd, void* resp, long resplen, unsigned int > timeout) > struct rtpg_command cmd; > struct sg_io_hdr hdr; > unsigned char sense[SENSE_BUFF_LEN]; > + int retry_count = 3, rc; > > +retry: > memset(&cmd, 0, sizeof(cmd)); > cmd.op = OPERATION_CODE_RTPG; > rtpg_command_set_service_action(&cmd); > @@ -286,9 +321,15 @@ do_rtpg(int fd, void* resp, long resplen, unsigned int > timeout) > if (ioctl(fd, SG_IO, &hdr) < 0) > return -RTPG_RTPG_FAILED; > > - if (scsi_error(&hdr)) { > + rc = scsi_error(&hdr, OPERATION_CODE_RTPG); > + if (rc == SCSI_ERROR) { > PRINT_DEBUG("do_rtpg: SCSI error!"); > return -RTPG_RTPG_FAILED; > + } else if (rc == SCSI_RETRY) { > + if (--retry_count >= 0) > + goto retry; > + PRINT_DEBUG("do_rtpg: retries exhausted!"); > + return -RTPG_RTPG_FAILED; > } > PRINT_HEX(resp, resplen); > > -- > 2.17.1
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