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authorBryan Gurney <bgurney@redhat.com>2019-10-22 16:46:01 -0400
committerMike Snitzer <snitzer@redhat.com>2019-11-05 15:25:34 -0500
commit72d7df4c8079306e7fbd6243bf951461ed647a47 (patch)
tree0203357542ba038301a43950d2d84aa740dc7bf7 /drivers/md
parentcc7a7fb3b689996d35404080dde09de03fc1d09b (diff)
dm dust: add limited write failure mode
Add a limited write failure mode which allows a write to a block to fail a specified amount of times, prior to remapping. The "addbadblock" message is extended to allow specifying the limited number of times a write fails. Example: add bad block on block 60, with 5 write failures: dmsetup message 0 dust1 addbadblock 60 5 The write failure counter will be printed for newly added bad blocks. Signed-off-by: Bryan Gurney <bgurney@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/dm-dust.c53
1 files changed, 46 insertions, 7 deletions
diff --git a/drivers/md/dm-dust.c b/drivers/md/dm-dust.c
index 9a926a799fb4..eb37584427a4 100644
--- a/drivers/md/dm-dust.c
+++ b/drivers/md/dm-dust.c
@@ -17,6 +17,7 @@
struct badblock {
struct rb_node node;
sector_t bb;
+ unsigned char wr_fail_cnt;
};
struct dust_device {
@@ -101,7 +102,8 @@ static int dust_remove_block(struct dust_device *dd, unsigned long long block)
return 0;
}
-static int dust_add_block(struct dust_device *dd, unsigned long long block)
+static int dust_add_block(struct dust_device *dd, unsigned long long block,
+ unsigned char wr_fail_cnt)
{
struct badblock *bblock;
unsigned long flags;
@@ -115,6 +117,7 @@ static int dust_add_block(struct dust_device *dd, unsigned long long block)
spin_lock_irqsave(&dd->dust_lock, flags);
bblock->bb = block;
+ bblock->wr_fail_cnt = wr_fail_cnt;
if (!dust_rb_insert(&dd->badblocklist, bblock)) {
if (!dd->quiet_mode) {
DMERR("%s: block %llu already in badblocklist",
@@ -126,8 +129,10 @@ static int dust_add_block(struct dust_device *dd, unsigned long long block)
}
dd->badblock_count++;
- if (!dd->quiet_mode)
- DMINFO("%s: badblock added at block %llu", __func__, block);
+ if (!dd->quiet_mode) {
+ DMINFO("%s: badblock added at block %llu with write fail count %hhu",
+ __func__, block, wr_fail_cnt);
+ }
spin_unlock_irqrestore(&dd->dust_lock, flags);
return 0;
@@ -175,10 +180,15 @@ static int dust_map_read(struct dust_device *dd, sector_t thisblock,
return r;
}
-static void __dust_map_write(struct dust_device *dd, sector_t thisblock)
+static int __dust_map_write(struct dust_device *dd, sector_t thisblock)
{
struct badblock *bblk = dust_rb_search(&dd->badblocklist, thisblock);
+ if (bblk && bblk->wr_fail_cnt > 0) {
+ bblk->wr_fail_cnt--;
+ return DM_MAPIO_KILL;
+ }
+
if (bblk) {
rb_erase(&bblk->node, &dd->badblocklist);
dd->badblock_count--;
@@ -189,21 +199,24 @@ static void __dust_map_write(struct dust_device *dd, sector_t thisblock)
(unsigned long long)thisblock);
}
}
+
+ return DM_MAPIO_REMAPPED;
}
static int dust_map_write(struct dust_device *dd, sector_t thisblock,
bool fail_read_on_bb)
{
unsigned long flags;
+ int ret = DM_MAPIO_REMAPPED;
if (fail_read_on_bb) {
thisblock >>= dd->sect_per_block_shift;
spin_lock_irqsave(&dd->dust_lock, flags);
- __dust_map_write(dd, thisblock);
+ ret = __dust_map_write(dd, thisblock);
spin_unlock_irqrestore(&dd->dust_lock, flags);
}
- return DM_MAPIO_REMAPPED;
+ return ret;
}
static int dust_map(struct dm_target *ti, struct bio *bio)
@@ -377,6 +390,8 @@ static int dust_message(struct dm_target *ti, unsigned int argc, char **argv,
bool invalid_msg = false;
int r = -EINVAL;
unsigned long long tmp, block;
+ unsigned char wr_fail_cnt;
+ unsigned int tmp_ui;
unsigned long flags;
char dummy;
@@ -422,7 +437,7 @@ static int dust_message(struct dm_target *ti, unsigned int argc, char **argv,
}
if (!strcasecmp(argv[0], "addbadblock"))
- r = dust_add_block(dd, block);
+ r = dust_add_block(dd, block, 0);
else if (!strcasecmp(argv[0], "removebadblock"))
r = dust_remove_block(dd, block);
else if (!strcasecmp(argv[0], "queryblock"))
@@ -430,6 +445,30 @@ static int dust_message(struct dm_target *ti, unsigned int argc, char **argv,
else
invalid_msg = true;
+ } else if (argc == 3) {
+ if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1)
+ return r;
+
+ if (sscanf(argv[2], "%u%c", &tmp_ui, &dummy) != 1)
+ return r;
+
+ block = tmp;
+ if (tmp_ui > 255) {
+ DMERR("selected write fail count out of range");
+ return r;
+ }
+ wr_fail_cnt = tmp_ui;
+ sector_div(size, dd->sect_per_block);
+ if (block > size) {
+ DMERR("selected block value out of range");
+ return r;
+ }
+
+ if (!strcasecmp(argv[0], "addbadblock"))
+ r = dust_add_block(dd, block, wr_fail_cnt);
+ else
+ invalid_msg = true;
+
} else
DMERR("invalid number of arguments '%d'", argc);