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path: root/drivers/md/dm-switch.c
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Diffstat (limited to 'drivers/md/dm-switch.c')
-rw-r--r--drivers/md/dm-switch.c67
1 files changed, 60 insertions, 7 deletions
diff --git a/drivers/md/dm-switch.c b/drivers/md/dm-switch.c
index 09a688b3d48..50fca469caf 100644
--- a/drivers/md/dm-switch.c
+++ b/drivers/md/dm-switch.c
@@ -137,13 +137,23 @@ static void switch_get_position(struct switch_ctx *sctx, unsigned long region_nr
*bit *= sctx->region_table_entry_bits;
}
+static unsigned switch_region_table_read(struct switch_ctx *sctx, unsigned long region_nr)
+{
+ unsigned long region_index;
+ unsigned bit;
+
+ switch_get_position(sctx, region_nr, &region_index, &bit);
+
+ return (ACCESS_ONCE(sctx->region_table[region_index]) >> bit) &
+ ((1 << sctx->region_table_entry_bits) - 1);
+}
+
/*
* Find which path to use at given offset.
*/
static unsigned switch_get_path_nr(struct switch_ctx *sctx, sector_t offset)
{
- unsigned long region_index;
- unsigned bit, path_nr;
+ unsigned path_nr;
sector_t p;
p = offset;
@@ -152,9 +162,7 @@ static unsigned switch_get_path_nr(struct switch_ctx *sctx, sector_t offset)
else
sector_div(p, sctx->region_size);
- switch_get_position(sctx, p, &region_index, &bit);
- path_nr = (ACCESS_ONCE(sctx->region_table[region_index]) >> bit) &
- ((1 << sctx->region_table_entry_bits) - 1);
+ path_nr = switch_region_table_read(sctx, p);
/* This can only happen if the processor uses non-atomic stores. */
if (unlikely(path_nr >= sctx->nr_paths))
@@ -363,7 +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;
@@ -372,6 +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 {
@@ -500,7 +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,