Commit 8c0f0e8c authored by Mike Snitzer's avatar Mike Snitzer

dm thin: requeue bios to DM core if no_free_space and in read-only mode

Now that we switch the pool to read-only mode when the data device runs
out of space it causes active writers to get IO errors once we resume
after resizing the data device.

If no_free_space is set, save bios to the 'retry_on_resume_list' and
requeue them on resume (once the data or metadata device may have been
resized).

With this patch the resize_io test passes again (on slower storage):
 dmtest run --suite thin-provisioning -n /resize_io/

Later patches fix some subtle races associated with the pool mode
transitions done as part of the pool's -ENOSPC handling.  These races
are exposed on fast storage (e.g. PCIe SSD).
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Acked-by: default avatarJoe Thornber <ejt@redhat.com>
parent 399caddf
...@@ -164,7 +164,7 @@ struct pool { ...@@ -164,7 +164,7 @@ struct pool {
struct pool_features pf; struct pool_features pf;
bool low_water_triggered:1; /* A dm event has been sent */ bool low_water_triggered:1; /* A dm event has been sent */
bool no_free_space:1; /* A -ENOSPC warning has been issued */ bool no_free_space:1; /* bios will be requeued if set */
struct dm_bio_prison *prison; struct dm_bio_prison *prison;
struct dm_kcopyd_client *copier; struct dm_kcopyd_client *copier;
...@@ -982,6 +982,20 @@ static void retry_on_resume(struct bio *bio) ...@@ -982,6 +982,20 @@ static void retry_on_resume(struct bio *bio)
spin_unlock_irqrestore(&pool->lock, flags); spin_unlock_irqrestore(&pool->lock, flags);
} }
static void handle_unserviceable_bio(struct pool *pool, struct bio *bio)
{
/*
* When pool is read-only, no cell locking is needed because
* nothing is changing.
*/
WARN_ON_ONCE(get_pool_mode(pool) != PM_READ_ONLY);
if (pool->no_free_space)
retry_on_resume(bio);
else
bio_io_error(bio);
}
static void retry_bios_on_resume(struct pool *pool, struct dm_bio_prison_cell *cell) static void retry_bios_on_resume(struct pool *pool, struct dm_bio_prison_cell *cell)
{ {
struct bio *bio; struct bio *bio;
...@@ -991,7 +1005,7 @@ static void retry_bios_on_resume(struct pool *pool, struct dm_bio_prison_cell *c ...@@ -991,7 +1005,7 @@ static void retry_bios_on_resume(struct pool *pool, struct dm_bio_prison_cell *c
cell_release(pool, cell, &bios); cell_release(pool, cell, &bios);
while ((bio = bio_list_pop(&bios))) while ((bio = bio_list_pop(&bios)))
retry_on_resume(bio); handle_unserviceable_bio(pool, bio);
} }
static void process_discard(struct thin_c *tc, struct bio *bio) static void process_discard(struct thin_c *tc, struct bio *bio)
...@@ -1245,7 +1259,7 @@ static void process_bio_read_only(struct thin_c *tc, struct bio *bio) ...@@ -1245,7 +1259,7 @@ static void process_bio_read_only(struct thin_c *tc, struct bio *bio)
switch (r) { switch (r) {
case 0: case 0:
if (lookup_result.shared && (rw == WRITE) && bio->bi_size) if (lookup_result.shared && (rw == WRITE) && bio->bi_size)
bio_io_error(bio); handle_unserviceable_bio(tc->pool, bio);
else { else {
inc_all_io_entry(tc->pool, bio); inc_all_io_entry(tc->pool, bio);
remap_and_issue(tc, bio, lookup_result.block); remap_and_issue(tc, bio, lookup_result.block);
...@@ -1254,7 +1268,7 @@ static void process_bio_read_only(struct thin_c *tc, struct bio *bio) ...@@ -1254,7 +1268,7 @@ static void process_bio_read_only(struct thin_c *tc, struct bio *bio)
case -ENODATA: case -ENODATA:
if (rw != READ) { if (rw != READ) {
bio_io_error(bio); handle_unserviceable_bio(tc->pool, bio);
break; break;
} }
...@@ -1565,9 +1579,9 @@ static int thin_bio_map(struct dm_target *ti, struct bio *bio) ...@@ -1565,9 +1579,9 @@ static int thin_bio_map(struct dm_target *ti, struct bio *bio)
if (get_pool_mode(tc->pool) == PM_READ_ONLY) { if (get_pool_mode(tc->pool) == PM_READ_ONLY) {
/* /*
* This block isn't provisioned, and we have no way * This block isn't provisioned, and we have no way
* of doing so. Just error it. * of doing so.
*/ */
bio_io_error(bio); handle_unserviceable_bio(tc->pool, bio);
return DM_MAPIO_SUBMITTED; return DM_MAPIO_SUBMITTED;
} }
/* fall through */ /* fall through */
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment