struct pool_features {
enum pool_mode mode;
- unsigned zero_new_blocks:1;
- unsigned discard_enabled:1;
- unsigned discard_passdown:1;
+ bool zero_new_blocks:1;
+ bool discard_enabled:1;
+ bool discard_passdown:1;
};
struct thin_c;
struct dm_target_callbacks callbacks;
dm_block_t low_water_blocks;
- struct pool_features pf;
+ struct pool_features requested_pf; /* Features requested during table load */
+ struct pool_features adjusted_pf; /* Features used after adjusting for constituent devices */
};
/*
/*----------------------------------------------------------------
* Binding of control targets to a pool object
*--------------------------------------------------------------*/
+static bool data_dev_supports_discard(struct pool_c *pt)
+{
+ struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
+
+ return q && blk_queue_discard(q);
+}
+
+/*
+ * If discard_passdown was enabled verify that the data device
+ * supports discards. Disable discard_passdown if not.
+ */
+static void disable_passdown_if_not_supported(struct pool_c *pt)
+{
+ struct pool *pool = pt->pool;
+ struct block_device *data_bdev = pt->data_dev->bdev;
+ struct queue_limits *data_limits = &bdev_get_queue(data_bdev)->limits;
+ sector_t block_size = pool->sectors_per_block << SECTOR_SHIFT;
+ const char *reason = NULL;
+ char buf[BDEVNAME_SIZE];
+
+ if (!pt->adjusted_pf.discard_passdown)
+ return;
+
+ if (!data_dev_supports_discard(pt))
+ reason = "discard unsupported";
+
+ else if (data_limits->max_discard_sectors < pool->sectors_per_block)
+ reason = "max discard sectors smaller than a block";
+
+ else if (data_limits->discard_granularity > block_size)
+ reason = "discard granularity larger than a block";
+
+ else if (block_size & (data_limits->discard_granularity - 1))
+ reason = "discard granularity not a factor of block size";
+
+ if (reason) {
+ DMWARN("Data device (%s) %s: Disabling discard passdown.", bdevname(data_bdev, buf), reason);
+ pt->adjusted_pf.discard_passdown = false;
+ }
+}
+
static int bind_control_target(struct pool *pool, struct dm_target *ti)
{
struct pool_c *pt = ti->private;
* We want to make sure that degraded pools are never upgraded.
*/
enum pool_mode old_mode = pool->pf.mode;
- enum pool_mode new_mode = pt->pf.mode;
+ enum pool_mode new_mode = pt->adjusted_pf.mode;
if (old_mode > new_mode)
new_mode = old_mode;
pool->ti = ti;
pool->low_water_blocks = pt->low_water_blocks;
- pool->pf = pt->pf;
- set_pool_mode(pool, new_mode);
+ pool->pf = pt->adjusted_pf;
- /*
- * If discard_passdown was enabled verify that the data device
- * supports discards. Disable discard_passdown if not; otherwise
- * -EOPNOTSUPP will be returned.
- */
- /* FIXME: pull this out into a sep fn. */
- if (pt->pf.discard_passdown) {
- struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
- if (!q || !blk_queue_discard(q)) {
- char buf[BDEVNAME_SIZE];
- DMWARN("Discard unsupported by data device (%s): Disabling discard passdown.",
- bdevname(pt->data_dev->bdev, buf));
- pool->pf.discard_passdown = 0;
- }
- }
+ set_pool_mode(pool, new_mode);
return 0;
}
static void pool_features_init(struct pool_features *pf)
{
pf->mode = PM_WRITE;
- pf->zero_new_blocks = 1;
- pf->discard_enabled = 1;
- pf->discard_passdown = 1;
+ pf->zero_new_blocks = true;
+ pf->discard_enabled = true;
+ pf->discard_passdown = true;
}
static void __pool_destroy(struct pool *pool)
argc--;
if (!strcasecmp(arg_name, "skip_block_zeroing"))
- pf->zero_new_blocks = 0;
+ pf->zero_new_blocks = false;
else if (!strcasecmp(arg_name, "ignore_discard"))
- pf->discard_enabled = 0;
+ pf->discard_enabled = false;
else if (!strcasecmp(arg_name, "no_discard_passdown"))
- pf->discard_passdown = 0;
+ pf->discard_passdown = false;
else if (!strcasecmp(arg_name, "read_only"))
pf->mode = PM_READ_ONLY;
pt->metadata_dev = metadata_dev;
pt->data_dev = data_dev;
pt->low_water_blocks = low_water_blocks;
- pt->pf = pf;
+ pt->adjusted_pf = pt->requested_pf = pf;
ti->num_flush_requests = 1;
+
/*
* Only need to enable discards if the pool should pass
* them down to the data device. The thin device's discard
*/
if (pf.discard_enabled && pf.discard_passdown) {
ti->num_discard_requests = 1;
+
/*
* Setting 'discards_supported' circumvents the normal
* stacking of discard limits (this keeps the pool and
* thin devices' discard limits consistent).
*/
ti->discards_supported = true;
+ ti->discard_zeroes_data_unsupported = true;
}
ti->private = pt;
format_dev_t(buf2, pt->data_dev->bdev->bd_dev),
(unsigned long)pool->sectors_per_block,
(unsigned long long)pt->low_water_blocks);
- emit_flags(&pt->pf, result, sz, maxlen);
+ emit_flags(&pt->requested_pf, result, sz, maxlen);
break;
}
return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
}
-static void set_discard_limits(struct pool *pool, struct queue_limits *limits)
+static void set_discard_limits(struct pool_c *pt, struct queue_limits *limits)
{
- /*
- * FIXME: these limits may be incompatible with the pool's data device
- */
+ struct pool *pool = pt->pool;
+ struct queue_limits *data_limits;
+
limits->max_discard_sectors = pool->sectors_per_block;
/*
- * This is just a hint, and not enforced. We have to cope with
- * bios that cover a block partially. A discard that spans a block
- * boundary is not sent to this target.
+ * discard_granularity is just a hint, and not enforced.
*/
- limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT;
- limits->discard_zeroes_data = pool->pf.zero_new_blocks;
+ if (pt->adjusted_pf.discard_passdown) {
+ data_limits = &bdev_get_queue(pt->data_dev->bdev)->limits;
+ limits->discard_granularity = data_limits->discard_granularity;
+ } else
+ limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT;
}
static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits)
blk_limits_io_min(limits, 0);
blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT);
- if (pool->pf.discard_enabled)
- set_discard_limits(pool, limits);
+
+ /*
+ * pt->adjusted_pf is a staging area for the actual features to use.
+ * They get transferred to the live pool in bind_control_target()
+ * called from pool_preresume().
+ */
+ if (!pt->adjusted_pf.discard_enabled)
+ return;
+
+ disable_passdown_if_not_supported(pt);
+
+ set_discard_limits(pt, limits);
}
static struct target_type pool_target = {
.name = "thin-pool",
.features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE |
DM_TARGET_IMMUTABLE,
- .version = {1, 3, 0},
+ .version = {1, 4, 0},
.module = THIS_MODULE,
.ctr = pool_ctr,
.dtr = pool_dtr,
return 0;
}
+/*
+ * A thin device always inherits its queue limits from its pool.
+ */
static void thin_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
struct thin_c *tc = ti->private;
- struct pool *pool = tc->pool;
- blk_limits_io_min(limits, 0);
- blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT);
- set_discard_limits(pool, limits);
+ *limits = bdev_get_queue(tc->pool_dev->bdev)->limits;
}
static struct target_type thin_target = {
.name = "thin",
- .version = {1, 3, 0},
+ .version = {1, 4, 0},
.module = THIS_MODULE,
.ctr = thin_ctr,
.dtr = thin_dtr,
projects / karo-tx-linux.git / blobdiff