[PATCH 5.2 136/162] dm dust: use dust block size for badblocklist index

Greg Kroah-Hartman
2019-08-27T08:05:54Z

From: Bryan Gurney <bgurney@redhat.com>

commit 08c04c84a5cde3af9baac0645a7496d6dcd76822 upstream.

Change the "frontend" dust_remove_block, dust_add_block, and
dust_query_block functions to store the "dust block number", instead
of the sector number corresponding to the "dust block number".

For the "backend" functions dust_map_read and dust_map_write,
right-shift by sect_per_block_shift. This fixes the inability to
emulate failure beyond the first sector of each "dust block" (for
devices with a "dust block size" larger than 512 bytes).

Fixes: e4f3fabd67480bf ("dm: add dust target")
Cc: stable@vger.kernel.org
Signed-off-by: Bryan Gurney <bgurney@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/md/dm-dust.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

--- a/drivers/md/dm-dust.c
+++ b/drivers/md/dm-dust.c
@@ -25,6 +25,7 @@ struct dust_device {
unsigned long long badblock_count;
spinlock_t dust_lock;
unsigned int blksz;
+ int sect_per_block_shift;
unsigned int sect_per_block;
sector_t start;
bool fail_read_on_bb:1;
@@ -79,7 +80,7 @@ static int dust_remove_block(struct dust
unsigned long flags;

spin_lock_irqsave(&dd->dust_lock, flags);
- bblock = dust_rb_search(&dd->badblocklist, block * dd->sect_per_block);
+ bblock = dust_rb_search(&dd->badblocklist, block);

if (bblock == NULL) {
if (!dd->quiet_mode) {
@@ -113,7 +114,7 @@ static int dust_add_block(struct dust_de
}

spin_lock_irqsave(&dd->dust_lock, flags);
- bblock->bb = block * dd->sect_per_block;
+ bblock->bb = block;
if (!dust_rb_insert(&dd->badblocklist, bblock)) {
if (!dd->quiet_mode) {
DMERR("%s: block %llu already in badblocklist",
@@ -138,7 +139,7 @@ static int dust_query_block(struct dust_
unsigned long flags;

spin_lock_irqsave(&dd->dust_lock, flags);
- bblock = dust_rb_search(&dd->badblocklist, block * dd->sect_per_block);
+ bblock = dust_rb_search(&dd->badblocklist, block);
if (bblock != NULL)
DMINFO("%s: block %llu found in badblocklist", __func__, block);
else
@@ -165,6 +166,7 @@ static int dust_map_read(struct dust_dev
int ret = DM_MAPIO_REMAPPED;

if (fail_read_on_bb) {
+ thisblock >>= dd->sect_per_block_shift;
spin_lock_irqsave(&dd->dust_lock, flags);
ret = __dust_map_read(dd, thisblock);
spin_unlock_irqrestore(&dd->dust_lock, flags);
@@ -195,6 +197,7 @@ static int dust_map_write(struct dust_de
unsigned long flags;

if (fail_read_on_bb) {
+ thisblock >>= dd->sect_per_block_shift;
spin_lock_irqsave(&dd->dust_lock, flags);
__dust_map_write(dd, thisblock);
spin_unlock_irqrestore(&dd->dust_lock, flags);
@@ -331,6 +334,8 @@ static int dust_ctr(struct dm_target *ti
dd->blksz = blksz;
dd->start = tmp;

+ dd->sect_per_block_shift = __ffs(sect_per_block);
+
/*
* Whether to fail a read on a "bad" block.
* Defaults to false; enabled later by message.