> > Based on "[PATH V2] scsi_debug: rework resp_report_luns" patch sent by > Tomas Winkler on Thursday, 26 Feb 2015. His notes: > 1. Remove duplicated boundary checks which simplify the fill-in > loop > 2. Use more of scsi generic API > Replace fixed length response array a with heap allocation allowing up to > 16383 LUNs per target. > > Signed-off-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx> You can add my signed off. Tomas > --- > drivers/scsi/scsi_debug.c | 138 ++++++++++++++++++++++++++++++------------ > ---- > 1 file changed, 91 insertions(+), 47 deletions(-) > > diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index > cf44ab0..eac62b8 100644 > --- a/drivers/scsi/scsi_debug.c > +++ b/drivers/scsi/scsi_debug.c > @@ -3205,63 +3205,99 @@ static int resp_get_lba_status(struct scsi_cmnd > *scp, > return fill_from_dev_buffer(scp, arr, > SDEBUG_GET_LBA_STATUS_LEN); } > > -#define SDEBUG_RLUN_ARR_SZ 256 > - > -static int resp_report_luns(struct scsi_cmnd * scp, > - struct sdebug_dev_info * devip) > +/* Even though each pseudo target has a REPORT LUNS "well known logical > unit" > + * (W-LUN), the normal Linux scanning logic does not associate it with > +a > + * device (e.g. /dev/sg7). The following magic will make that association: > + * "cd /sys/class/scsi_host/host<n> ; echo '- - 49409' > scan" > + * where <n> is a host number. If there are multiple targets in a host > +then > + * the above will associate a W-LUN to each target. To only get a W-LUN > + * for target 2, then use "echo '- 2 49409' > scan" . */ static int > +resp_report_luns(struct scsi_cmnd *scp, > + struct sdebug_dev_info *devip) > { > + unsigned char *cmd = scp->cmnd; > unsigned int alloc_len; > - int lun_cnt, i, upper, num, n, want_wlun, shortish; > + unsigned char select_report; > u64 lun; > - unsigned char *cmd = scp->cmnd; > - int select_report = (int)cmd[2]; > - struct scsi_lun *one_lun; > - unsigned char arr[SDEBUG_RLUN_ARR_SZ]; > - unsigned char * max_addr; > + struct scsi_lun *lun_p; > + u8 *arr; > + unsigned int lun_cnt; /* normal LUN count (max: 16383) */ > + unsigned int wlun_cnt; /* report luns W-LUN count */ > + unsigned int tlun_cnt; /* total LUN count */ > + unsigned int rlen; /* response length (in bytes) less header */ > + int i, res; > > clear_luns_changed_on_target(devip); > - alloc_len = cmd[9] + (cmd[8] << 8) + (cmd[7] << 16) + (cmd[6] << 24); > - shortish = (alloc_len < 4); > - if (shortish || (select_report > 2)) { > - mk_sense_invalid_fld(scp, SDEB_IN_CDB, shortish ? 6 : 2, -1); > + > + select_report = cmd[2]; > + alloc_len = get_unaligned_be32(cmd + 6); > + > + if (alloc_len < 4) { > + pr_err("alloc len too small %d\n", alloc_len); > + mk_sense_invalid_fld(scp, SDEB_IN_CDB, 6, -1); > return check_condition_result; > } > - /* can produce response with up to 16k luns (lun 0 to lun 16383) */ > - memset(arr, 0, SDEBUG_RLUN_ARR_SZ); > + > + if (select_report > 0x02) { > + pr_err("select report invalid %d\n", select_report); > + mk_sense_invalid_fld(scp, SDEB_IN_CDB, 2, -1); > + return check_condition_result; > + } > + > lun_cnt = sdebug_max_luns; > - if (1 == select_report) > + wlun_cnt = 0; > + > + /* report only w_lun */ > + if (select_report == 0x01) > lun_cnt = 0; > - else if (sdebug_no_lun_0 && (lun_cnt > 0)) > + > + if (sdebug_no_lun_0 && (lun_cnt > 0)) > --lun_cnt; > - want_wlun = (select_report > 0) ? 1 : 0; > - num = lun_cnt + want_wlun; > - arr[2] = ((sizeof(struct scsi_lun) * num) >> 8) & 0xff; > - arr[3] = (sizeof(struct scsi_lun) * num) & 0xff; > - n = min((int)((SDEBUG_RLUN_ARR_SZ - 8) / > - sizeof(struct scsi_lun)), num); > - if (n < num) { > - want_wlun = 0; > - lun_cnt = n; > - } > - one_lun = (struct scsi_lun *) &arr[8]; > - max_addr = arr + SDEBUG_RLUN_ARR_SZ; > - for (i = 0, lun = (sdebug_no_lun_0 ? 1 : 0); > - ((i < lun_cnt) && ((unsigned char *)(one_lun + i) < max_addr)); > - i++, lun++) { > - upper = (lun >> 8) & 0x3f; > - if (upper) > - one_lun[i].scsi_lun[0] = > - (upper | (SAM2_LUN_ADDRESS_METHOD << 6)); > - one_lun[i].scsi_lun[1] = lun & 0xff; > - } > - if (want_wlun) { > - one_lun[i].scsi_lun[0] = (SCSI_W_LUN_REPORT_LUNS >> 8) & > 0xff; > - one_lun[i].scsi_lun[1] = SCSI_W_LUN_REPORT_LUNS & 0xff; > - i++; > - } > - alloc_len = (unsigned char *)(one_lun + i) - arr; > - return fill_from_dev_buffer(scp, arr, > - min((int)alloc_len, > SDEBUG_RLUN_ARR_SZ)); > + > + /* report w_lun */ > + if (select_report == 0x01 || select_report == 0x02) > + wlun_cnt = 1; > + > + tlun_cnt = lun_cnt + wlun_cnt; > + /* can produce response with up to 16k luns (lun 0 to lun 16383) */ > + arr = kzalloc((tlun_cnt * sizeof(lun_p->scsi_lun)) + 8, GFP_ATOMIC); > + if (!arr) { > + pr_warn("No space for report luns response\n"); > + mk_sense_buffer(scp, ILLEGAL_REQUEST, INSUFF_RES_ASC, > + INSUFF_RES_ASCQ); > + return check_condition_result; > + } > + pr_debug("select_report %d luns = %d wluns = %d no_lun0 %d\n", > + select_report, lun_cnt, wlun_cnt, sdebug_no_lun_0); > + > + lun = 0LL; > + /* luns start at offset 8 after the byte length */ > + lun_p = (struct scsi_lun *)&arr[8]; > + > + /* skip lun 0 */ > + if (sdebug_no_lun_0) > + lun++; > + /* > + * Address method (we use Peripherial = 00b) > + * 10b - Logical unit > + * 00b - Peripherial device - Use this one > + * 01b - Logical device > + * 11b - reserved > + */ > + for (i = 0; i < lun_cnt; i++) > + int_to_scsilun(lun++, lun_p++); > + > + /* report SCSI_W_LUN_REPORT_LUN */ > + if (wlun_cnt) > + int_to_scsilun(SCSI_W_LUN_REPORT_LUNS, lun_p++); > + > + rlen = tlun_cnt * sizeof(struct scsi_lun); > + > + put_unaligned_be32(rlen, &arr[0]); > + > + res = fill_from_dev_buffer(scp, arr, rlen + 8); > + kfree(arr); > + return res; > } > > static int resp_xdwriteread(struct scsi_cmnd *scp, unsigned long long lba, > @@ -4299,6 +4335,10 @@ static ssize_t max_luns_store(struct device_driver > *ddp, const char *buf, > bool changed; > > if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) { > + if (n > 16383) { > + pr_warn("max_luns can be no more than 16383\n"); > + return -EINVAL; > + } > changed = (sdebug_max_luns != n); > sdebug_max_luns = n; > sdebug_max_tgts_luns(); > @@ -4643,6 +4683,10 @@ static int __init scsi_debug_init(void) > pr_err("invalid physblk_exp %u\n", sdebug_physblk_exp); > return -EINVAL; > } > + if (sdebug_max_luns > 16383) { > + pr_warn("max_luns can be no more than 16383, use > default\n"); > + sdebug_max_luns = DEF_MAX_LUNS; > + } > > if (sdebug_lowest_aligned > 0x3fff) { > pr_err("lowest_aligned too big: %u\n", > sdebug_lowest_aligned); > -- > 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html