diff options
| -rw-r--r-- | Documentation/device-mapper/switch.txt | 12 | ||||
| -rw-r--r-- | drivers/md/dm-switch.c | 49 |
2 files changed, 59 insertions, 2 deletions
diff --git a/Documentation/device-mapper/switch.txt b/Documentation/device-mapper/switch.txt index 2fa7493..8897d04 100644 --- a/Documentation/device-mapper/switch.txt +++ b/Documentation/device-mapper/switch.txt @@ -106,6 +106,11 @@ which paths. The path number in the range 0 ... (<num_paths> - 1). Expressed in hexadecimal (WITHOUT any prefix like 0x). +R<n>,<m> + This parameter allows repetitive patterns to be loaded quickly. <n> and <m> + are hexadecimal numbers. The last <n> mappings are repeated in the next <m> + slots. + Status ====== @@ -124,3 +129,10 @@ Create a switch device with 64kB region size: Set mappings for the first 7 entries to point to devices switch0, switch1, switch2, switch0, switch1, switch2, switch1: dmsetup message switch 0 set_region_mappings 0:0 :1 :2 :0 :1 :2 :1 + +Set repetitive mapping. This command: + dmsetup message switch 0 set_region_mappings 1000:1 :2 R2,10 +is equivalent to: + dmsetup message switch 0 set_region_mappings 1000:1 :2 :1 :2 :1 :2 :1 :2 \ + :1 :2 :1 :2 :1 :2 :1 :2 :1 :2 + diff --git a/drivers/md/dm-switch.c b/drivers/md/dm-switch.c index c40e095..50fca46 100644 --- a/drivers/md/dm-switch.c +++ b/drivers/md/dm-switch.c @@ -371,7 +371,7 @@ static __always_inline unsigned long parse_hex(const char **string) } static int process_set_region_mappings(struct switch_ctx *sctx, - unsigned argc, char **argv) + unsigned argc, char **argv) { unsigned i; unsigned long region_index = 0; @@ -380,6 +380,51 @@ static int process_set_region_mappings(struct switch_ctx *sctx, unsigned long path_nr; const char *string = argv[i]; + if ((*string & 0xdf) == 'R') { + unsigned long cycle_length, num_write; + + string++; + if (unlikely(*string == ',')) { + DMWARN("invalid set_region_mappings argument: '%s'", argv[i]); + return -EINVAL; + } + cycle_length = parse_hex(&string); + if (unlikely(*string != ',')) { + DMWARN("invalid set_region_mappings argument: '%s'", argv[i]); + return -EINVAL; + } + string++; + if (unlikely(!*string)) { + DMWARN("invalid set_region_mappings argument: '%s'", argv[i]); + return -EINVAL; + } + num_write = parse_hex(&string); + if (unlikely(*string)) { + DMWARN("invalid set_region_mappings argument: '%s'", argv[i]); + return -EINVAL; + } + + if (unlikely(!cycle_length) || unlikely(cycle_length - 1 > region_index)) { + DMWARN("invalid set_region_mappings cycle length: %lu > %lu", + cycle_length - 1, region_index); + return -EINVAL; + } + if (unlikely(region_index + num_write < region_index) || + unlikely(region_index + num_write >= sctx->nr_regions)) { + DMWARN("invalid set_region_mappings region number: %lu + %lu >= %lu", + region_index, num_write, sctx->nr_regions); + return -EINVAL; + } + + while (num_write--) { + region_index++; + path_nr = switch_region_table_read(sctx, region_index - cycle_length); + switch_region_table_write(sctx, region_index, path_nr); + } + + continue; + } + if (*string == ':') region_index++; else { @@ -508,7 +553,7 @@ static int switch_iterate_devices(struct dm_target *ti, static struct target_type switch_target = { .name = "switch", - .version = {1, 0, 0}, + .version = {1, 1, 0}, .module = THIS_MODULE, .ctr = switch_ctr, .dtr = switch_dtr, |
