[PATCH 4.19 035/120] dm writecache: return the exact table values that were set

Greg Kroah-Hartman
2021-07-26T16:02:05Z

From: Mikulas Patocka <mpatocka@redhat.com>

commit 054bee16163df023e2589db09fd27d81f7ad9e72 upstream.

LVM doesn't like it when the target returns different values from what
was set in the constructor. Fix dm-writecache so that the returned
table values are exactly the same as requested values.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org # v4.18+
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/md/dm-writecache.c | 32 ++++++++++++++++----------------
1 file changed, 16 insertions(+), 16 deletions(-)

--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -153,6 +153,7 @@ struct dm_writecache {
bool overwrote_committed:1;
bool memory_vmapped:1;

+ bool start_sector_set:1;
bool high_wm_percent_set:1;
bool low_wm_percent_set:1;
bool max_writeback_jobs_set:1;
@@ -161,6 +162,10 @@ struct dm_writecache {
bool writeback_fua_set:1;
bool flush_on_suspend:1;

+ unsigned high_wm_percent_value;
+ unsigned low_wm_percent_value;
+ unsigned autocommit_time_value;
+
unsigned writeback_all;
struct workqueue_struct *writeback_wq;
struct work_struct writeback_work;
@@ -2045,6 +2050,7 @@ static int writecache_ctr(struct dm_targ
if (sscanf(string, "%llu%c", &start_sector, &dummy) != 1)
goto invalid_optional;
wc->start_sector = start_sector;
+ wc->start_sector_set = true;
if (wc->start_sector != start_sector ||
wc->start_sector >= wc->memory_map_size >> SECTOR_SHIFT)
goto invalid_optional;
@@ -2054,6 +2060,7 @@ static int writecache_ctr(struct dm_targ
goto invalid_optional;
if (high_wm_percent < 0 || high_wm_percent > 100)
goto invalid_optional;
+ wc->high_wm_percent_value = high_wm_percent;
wc->high_wm_percent_set = true;
} else if (!strcasecmp(string, "low_watermark") && opt_params >= 1) {
string = dm_shift_arg(&as), opt_params--;
@@ -2061,6 +2068,7 @@ static int writecache_ctr(struct dm_targ
goto invalid_optional;
if (low_wm_percent < 0 || low_wm_percent > 100)
goto invalid_optional;
+ wc->low_wm_percent_value = low_wm_percent;
wc->low_wm_percent_set = true;
} else if (!strcasecmp(string, "writeback_jobs") && opt_params >= 1) {
string = dm_shift_arg(&as), opt_params--;
@@ -2080,6 +2088,7 @@ static int writecache_ctr(struct dm_targ
if (autocommit_msecs > 3600000)
goto invalid_optional;
wc->autocommit_jiffies = msecs_to_jiffies(autocommit_msecs);
+ wc->autocommit_time_value = autocommit_msecs;
wc->autocommit_time_set = true;
} else if (!strcasecmp(string, "fua")) {
if (WC_MODE_PMEM(wc)) {
@@ -2275,7 +2284,6 @@ static void writecache_status(struct dm_
struct dm_writecache *wc = ti->private;
unsigned extra_args;
unsigned sz = 0;
- uint64_t x;

switch (type) {
case STATUSTYPE_INFO:
@@ -2287,7 +2295,7 @@ static void writecache_status(struct dm_
DMEMIT("%c %s %s %u ", WC_MODE_PMEM(wc) ? 'p' : 's',
wc->dev->name, wc->ssd_dev->name, wc->block_size);
extra_args = 0;
- if (wc->start_sector)
+ if (wc->start_sector_set)
extra_args += 2;
if (wc->high_wm_percent_set)
extra_args += 2;
@@ -2303,26 +2311,18 @@ static void writecache_status(struct dm_
extra_args++;

DMEMIT("%u", extra_args);
- if (wc->start_sector)
+ if (wc->start_sector_set)
DMEMIT(" start_sector %llu", (unsigned long long)wc->start_sector);
- if (wc->high_wm_percent_set) {
- x = (uint64_t)wc->freelist_high_watermark * 100;
- x += wc->n_blocks / 2;
- do_div(x, (size_t)wc->n_blocks);
- DMEMIT(" high_watermark %u", 100 - (unsigned)x);
- }
- if (wc->low_wm_percent_set) {
- x = (uint64_t)wc->freelist_low_watermark * 100;
- x += wc->n_blocks / 2;
- do_div(x, (size_t)wc->n_blocks);
- DMEMIT(" low_watermark %u", 100 - (unsigned)x);
- }
+ if (wc->high_wm_percent_set)
+ DMEMIT(" high_watermark %u", wc->high_wm_percent_value);
+ if (wc->low_wm_percent_set)
+ DMEMIT(" low_watermark %u", wc->low_wm_percent_value);
if (wc->max_writeback_jobs_set)
DMEMIT(" writeback_jobs %u", wc->max_writeback_jobs);
if (wc->autocommit_blocks_set)
DMEMIT(" autocommit_blocks %u", wc->autocommit_blocks);
if (wc->autocommit_time_set)
- DMEMIT(" autocommit_time %u", jiffies_to_msecs(wc->autocommit_jiffies));
+ DMEMIT(" autocommit_time %u", wc->autocommit_time_value);
if (wc->writeback_fua_set)
DMEMIT(" %sfua", wc->writeback_fua ? "" : "no");
break;