dm space map: optimise sm_ll_dec and sm_ll_inc
Prior to this patch these methods did a lookup followed by an insert. Instead they now call a common mutate function that adjusts the value according to a callback function. This avoids traversing the data structures twice and hence improves performance. Also factor out sm_ll_lookup_big_ref_count() for use by both sm_ll_lookup() and sm_ll_mutate(). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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Родитель
04f17c802f
Коммит
f722063ee0
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@ -292,16 +292,11 @@ int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
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return dm_tm_unlock(ll->tm, blk);
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}
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int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
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static int sm_ll_lookup_big_ref_count(struct ll_disk *ll, dm_block_t b,
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uint32_t *result)
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{
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__le32 le_rc;
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int r = sm_ll_lookup_bitmap(ll, b, result);
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if (r)
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return r;
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if (*result != 3)
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return r;
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int r;
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r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc);
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if (r < 0)
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@ -312,6 +307,19 @@ int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
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return r;
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}
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int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
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{
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int r = sm_ll_lookup_bitmap(ll, b, result);
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if (r)
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return r;
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if (*result != 3)
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return r;
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return sm_ll_lookup_big_ref_count(ll, b, result);
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}
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int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
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dm_block_t end, dm_block_t *result)
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{
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@ -372,11 +380,12 @@ int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
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return -ENOSPC;
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}
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int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
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uint32_t ref_count, enum allocation_event *ev)
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static int sm_ll_mutate(struct ll_disk *ll, dm_block_t b,
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uint32_t (*mutator)(void *context, uint32_t old),
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void *context, enum allocation_event *ev)
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{
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int r;
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uint32_t bit, old;
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uint32_t bit, old, ref_count;
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struct dm_block *nb;
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dm_block_t index = b;
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struct disk_index_entry ie_disk;
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@ -399,6 +408,14 @@ int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
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bm_le = dm_bitmap_data(nb);
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old = sm_lookup_bitmap(bm_le, bit);
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if (old > 2) {
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r = sm_ll_lookup_big_ref_count(ll, b, &old);
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if (r < 0)
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return r;
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}
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ref_count = mutator(context, old);
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if (ref_count <= 2) {
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sm_set_bitmap(bm_le, bit, ref_count);
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@ -448,31 +465,35 @@ int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
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return ll->save_ie(ll, index, &ie_disk);
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}
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static uint32_t set_ref_count(void *context, uint32_t old)
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{
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return *((uint32_t *) context);
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}
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int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
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uint32_t ref_count, enum allocation_event *ev)
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{
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return sm_ll_mutate(ll, b, set_ref_count, &ref_count, ev);
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}
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static uint32_t inc_ref_count(void *context, uint32_t old)
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{
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return old + 1;
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}
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int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
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{
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int r;
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uint32_t rc;
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return sm_ll_mutate(ll, b, inc_ref_count, NULL, ev);
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}
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r = sm_ll_lookup(ll, b, &rc);
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if (r)
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return r;
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return sm_ll_insert(ll, b, rc + 1, ev);
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static uint32_t dec_ref_count(void *context, uint32_t old)
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{
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return old - 1;
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}
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int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
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{
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int r;
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uint32_t rc;
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r = sm_ll_lookup(ll, b, &rc);
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if (r)
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return r;
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if (!rc)
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return -EINVAL;
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return sm_ll_insert(ll, b, rc - 1, ev);
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return sm_ll_mutate(ll, b, dec_ref_count, NULL, ev);
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}
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int sm_ll_commit(struct ll_disk *ll)
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