[Devel] [PATCH 10/10] ploop: Populate and maintain holes bitmap
Kirill Tkhai
ktkhai at virtuozzo.com
Tue Mar 26 18:19:29 MSK 2019
Holes bitmap is needed for allocation of next free cluster.
Otherwise we don't know, where cluster number should be taken.
TODO: Flag to handle broken allocs (set bit back)
Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
---
drivers/block/ploop/fmt_ploop1.c | 199 +++++++++++++++++++++++++++++++++++++-
drivers/block/ploop/map.c | 6 +
include/linux/ploop/ploop.h | 3 +
3 files changed, 205 insertions(+), 3 deletions(-)
diff --git a/drivers/block/ploop/fmt_ploop1.c b/drivers/block/ploop/fmt_ploop1.c
index 9cfc56296e5e..6212634a1c0e 100644
--- a/drivers/block/ploop/fmt_ploop1.c
+++ b/drivers/block/ploop/fmt_ploop1.c
@@ -23,6 +23,7 @@ struct ploop1_private
u64 bd_size;
u32 alloc_head;
sector_t l1_off;
+ u32 nr_bat_entries;
};
static unsigned int data_off_in_clusters(struct ploop_delta *delta)
@@ -78,6 +79,11 @@ static int ploop1_stop(struct ploop_delta * delta)
struct ploop_pvd_header *vh;
struct ploop1_private * ph = delta->priv;
+ if (delta->holes_bitmap) {
+ kvfree(delta->holes_bitmap);
+ delta->holes_bitmap = NULL;
+ }
+
if ((delta->flags & PLOOP_FMT_RDONLY) ||
test_bit(PLOOP_S_ABORT, &delta->plo->state))
return 0;
@@ -115,6 +121,70 @@ ploop1_compose(struct ploop_delta * delta, int nchunks, struct ploop_ctl_chunk *
return ploop_io_init(delta, nchunks, pc);
}
+static int populate_holes_bitmap(struct ploop_delta *delta,
+ struct ploop1_private *ph)
+{
+ unsigned int block, nr_blocks, size, off;
+ struct page *page;
+ sector_t sec;
+ u32 *index;
+ int i, ret;
+
+ if (test_bit(PLOOP_S_NO_FALLOC_DISCARD, &delta->plo->state))
+ return 0;
+
+ /* To do: add discard alignment for v1 */
+ if (delta->plo->fmt_version != PLOOP_FMT_V2)
+ return 0;
+
+ ret = -ENOMEM;
+ page = alloc_page(GFP_KERNEL);
+ if (!page)
+ return ret;
+
+ nr_blocks = ph->nr_bat_entries;
+ /* Bits to bytes */
+ size = DIV_ROUND_UP(nr_blocks, 8);
+
+ delta->holes_bitmap = kvmalloc(size, GFP_KERNEL);
+ if (!delta->holes_bitmap)
+ goto put_page;
+ memset(delta->holes_bitmap, 0xff, size);
+ for (i = nr_blocks; i < size * 8; i++)
+ clear_bit(i, delta->holes_bitmap);
+
+ block = 0;
+ while (block < nr_blocks) {
+ if (!ploop1_map_index(delta, block, &sec)) {
+ WARN_ONCE(1, "Can't map block\n");
+ goto put_page;
+ }
+ ret = delta->io.ops->sync_read(&delta->io, page,
+ 4096, 0, sec);
+ if (ret)
+ goto put_page;
+
+ off = block ? 0 : PLOOP_MAP_OFFSET;
+
+ index = page_address(page);
+ for (i = off; i < INDEX_PER_PAGE && block + i - off < nr_blocks; i++) {
+ if (index[i] != 0) {
+ clear_bit((index[i] >> ploop_map_log(delta->plo)) -
+ data_off_in_clusters(delta),
+ delta->holes_bitmap);
+ }
+ }
+
+ block += (block ? INDEX_PER_PAGE : INDEX_PER_PAGE - PLOOP_MAP_OFFSET);
+ }
+
+ ret = 0;
+
+put_page:
+ put_page(page);
+ return ret;
+}
+
static int
ploop1_open(struct ploop_delta * delta)
{
@@ -157,6 +227,7 @@ ploop1_open(struct ploop_delta * delta)
goto out_err;
ph->l1_off = le32_to_cpu(vh->m_FirstBlockOffset);
+ ph->nr_bat_entries = le32_to_cpu(vh->m_Size);
err = -EBUSY;
if (pvd_header_is_disk_in_use(vh))
@@ -237,12 +308,37 @@ static void
ploop1_allocate(struct ploop_delta * delta, struct ploop_request * preq,
struct bio_list * sbl, unsigned int size)
{
- if (delta->io.alloc_head >=
+ struct ploop1_private * ph = delta->priv;
+ cluster_t cluster = 0;
+ int ret;
+
+ if (delta->holes_bitmap) {
+ unsigned nr_clusters = ph->nr_bat_entries;
+
+ cluster = find_first_bit(delta->holes_bitmap, nr_clusters);
+ if (cluster >= nr_clusters) {
+ PLOOP_FAIL_REQUEST(preq, -ENOSPC);
+ return;
+ }
+ cluster += data_off_in_clusters(delta);
+ } else if (delta->io.alloc_head >=
(delta->max_delta_size >> delta->cluster_log)) {
PLOOP_FAIL_REQUEST(preq, -E2BIG);
return;
}
- ploop_submit_alloc(delta, preq, sbl, size, 0);
+
+ ret = ploop_submit_alloc(delta, preq, sbl, size, cluster);
+
+ if (ret == 1 && cluster) {
+ /* Success. Mark cluster as occupied */
+ cluster -= data_off_in_clusters(delta);
+ clear_bit(cluster, delta->holes_bitmap);
+ /*
+ * FIXME: but what about failing requests,
+ * which return success? Should we add
+ * a handler in ploop_complete_request()?
+ */
+ }
}
/* Call this when data write is complete */
@@ -261,6 +357,10 @@ ploop1_allocate_complete(struct ploop_delta * delta, struct ploop_request * preq
static void
ploop1_destroy(struct ploop_delta * delta)
{
+ if (delta->holes_bitmap) {
+ kvfree(delta->holes_bitmap);
+ delta->holes_bitmap = NULL;
+ }
ploop_io_destroy(&delta->io);
ploop1_destroy_priv(delta);
}
@@ -268,7 +368,14 @@ ploop1_destroy(struct ploop_delta * delta)
static int
ploop1_start(struct ploop_delta * delta)
{
- return 0;
+ struct ploop1_private *ph = delta->priv;
+ struct ploop_device *plo = delta->plo;
+
+ if (!list_is_singular(&plo->map.delta_list))
+ return 0;
+
+ return populate_holes_bitmap(delta, ph);
+
// return delta->io.ops->start(&delta->io);
}
@@ -372,6 +479,12 @@ ploop1_complete_snapshot(struct ploop_delta * delta, struct ploop_snapdata * sd)
if (err)
goto out;
+ if (delta->holes_bitmap) {
+ /* New top_delta will be added ahead @delta */
+ kvfree(delta->holes_bitmap);
+ delta->holes_bitmap = NULL;
+ }
+
delta->flags |= PLOOP_FMT_RDONLY;
return 0;
@@ -447,6 +560,16 @@ ploop1_start_merge(struct ploop_delta * delta, struct ploop_snapdata * sd)
return delta->io.ops->sync(&delta->io);
}
+static int
+ploop1_complete_merge(struct ploop_delta *delta)
+{
+ struct ploop1_private *ph = delta->priv;
+
+ if (delta->level != 0)
+ return 0;
+ return populate_holes_bitmap(delta, ph);
+}
+
static int ploop1_truncate(struct ploop_delta * delta, struct file * file,
__u32 alloc_head)
{
@@ -466,6 +589,43 @@ static int ploop1_truncate(struct ploop_delta * delta, struct file * file,
alloc_head);
}
+static int expand_holes_bitmap(struct ploop_delta *delta, unsigned int old_nr,
+ unsigned int nr)
+{
+ unsigned int i, size, old_size;
+ void *holes_bitmap;
+
+ if (!delta->holes_bitmap)
+ return 0;
+
+ old_size = DIV_ROUND_UP(old_nr, 8);
+ size = DIV_ROUND_UP(nr, 8);
+
+ if (WARN_ON(old_size > size))
+ return -EINVAL;
+
+ holes_bitmap = kvmalloc(size, GFP_KERNEL);
+ if (!holes_bitmap) {
+ pr_err("Can't allocate holes_bitmap\n");
+ return -ENOMEM;
+ }
+
+ memcpy(holes_bitmap, delta->holes_bitmap, old_size);
+ kvfree(delta->holes_bitmap);
+
+ /* Fill last old byte */
+ for (i = old_nr; i < old_size * 8; i++)
+ __set_bit(i - 1, holes_bitmap);
+ /* Fill all new bytes */
+ memset(holes_bitmap + old_size, 0xff, size - old_size);
+ /* Clear alignment bytes */
+ for (i = nr; i < size * 8; i++)
+ clear_bit(i, holes_bitmap);
+
+ delta->holes_bitmap = holes_bitmap;
+ return 0;
+}
+
static int
ploop1_prepare_grow(struct ploop_delta * delta, u64 *new_size, int *reloc)
{
@@ -523,6 +683,7 @@ static int ploop1_complete_grow(struct ploop_delta * delta, u64 new_size)
{
struct ploop_pvd_header *vh;
struct ploop1_private * ph = delta->priv;
+ unsigned int nr_bat_entries;
int err;
u32 vh_bsize; /* block size in sectors */
@@ -552,6 +713,11 @@ static int ploop1_complete_grow(struct ploop_delta * delta, u64 new_size)
vh->m_Cylinders = cpu_to_le32(vh->m_Cylinders);
vh->m_Size = cpu_to_le32(vh->m_Size);
vh->m_FirstBlockOffset = cpu_to_le32(vh->m_FirstBlockOffset);
+ nr_bat_entries = le32_to_cpu(vh->m_Size);
+
+ err = expand_holes_bitmap(delta, ph->nr_bat_entries, nr_bat_entries);
+ if (err)
+ return err;
/* keep hdr in ph->dyn_page and in map_node in sync */
ploop_update_map_hdr(&delta->plo->map, (u8 *)vh, sizeof(*vh));
@@ -566,10 +732,35 @@ static int ploop1_complete_grow(struct ploop_delta * delta, u64 new_size)
ph->bd_size = new_size;
ph->l1_off = le32_to_cpu(vh->m_FirstBlockOffset);
+ ph->nr_bat_entries = nr_bat_entries;
return 0;
}
+static void ploop1_add_free_blk(struct ploop_delta *delta, struct ploop_request *preq)
+{
+ struct map_node *m = preq->map;
+ cluster_t cluster;
+ map_index_t blk;
+ u32 idx;
+
+ if (!delta->holes_bitmap)
+ return;
+
+ idx = (preq->req_cluster + PLOOP_MAP_OFFSET) & (INDEX_PER_PAGE - 1);
+ blk = ((map_index_t *)page_address(m->page))[idx];
+
+ /* Reapeted discard? */
+ if (!blk)
+ return;
+
+ cluster = blk >> ploop_map_log(delta->plo);
+ cluster -= data_off_in_clusters(delta);
+
+ WARN_ON_ONCE(test_bit(cluster, delta->holes_bitmap));
+ set_bit(cluster, delta->holes_bitmap);
+}
+
static struct ploop_delta_ops ploop1_delta_ops =
{
.id = PLOOP_FMT_PLOOP1,
@@ -594,9 +785,11 @@ static struct ploop_delta_ops ploop1_delta_ops =
.complete_snapshot = ploop1_complete_snapshot,
.prepare_merge = ploop1_prepare_merge,
.start_merge = ploop1_start_merge,
+ .complete_merge = ploop1_complete_merge,
.truncate = ploop1_truncate,
.prepare_grow = ploop1_prepare_grow,
.complete_grow = ploop1_complete_grow,
+ .add_free_blk = ploop1_add_free_blk,
};
static int __init pfmt_ploop1_mod_init(void)
diff --git a/drivers/block/ploop/map.c b/drivers/block/ploop/map.c
index 8a28148c17cb..b8103cfcc79b 100644
--- a/drivers/block/ploop/map.c
+++ b/drivers/block/ploop/map.c
@@ -939,6 +939,9 @@ void ploop_index_update(struct ploop_request * preq)
copy_index_for_wb(page, m, top_delta->level);
+ if (!preq->iblock)
+ top_delta->ops->add_free_blk(top_delta, preq);
+
((map_index_t*)page_address(page))[idx] = preq->iblock << ploop_map_log(plo);
get_page(page);
@@ -1182,6 +1185,9 @@ static void map_wb_complete(struct map_node * m, int err)
preq->sinfo.wi.tpage = page;
idx = (preq->req_cluster + PLOOP_MAP_OFFSET) & (INDEX_PER_PAGE - 1);
+ if (!preq->iblock)
+ top_delta->ops->add_free_blk(top_delta, preq);
+
((map_index_t*)page_address(page))[idx] = preq->iblock << ploop_map_log(plo);
if (!main_preq) {
diff --git a/include/linux/ploop/ploop.h b/include/linux/ploop/ploop.h
index a730c2de7873..c3ced34e8909 100644
--- a/include/linux/ploop/ploop.h
+++ b/include/linux/ploop/ploop.h
@@ -287,6 +287,7 @@ struct ploop_delta_ops
int (*truncate)(struct ploop_delta *, struct file *, __u32 alloc_head);
int (*prepare_grow)(struct ploop_delta *, u64 *new_size, int *reloc);
int (*complete_grow)(struct ploop_delta *, u64 new_size);
+ void (*add_free_blk)(struct ploop_delta *, struct ploop_request *);
};
/* Virtual image. */
@@ -309,6 +310,8 @@ struct ploop_delta
struct kobject kobj;
u64 max_delta_size; /* in sectors */
+
+ void *holes_bitmap;
};
struct ploop_tunable
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