Convert the null_blk driver to use the xarray API instead of radix tree
API.
Testing:
Used blktests test suite (block and zbd suites) to test the current
null_blk driver and null_blk driver with this patch applied. The tests
results in both the instances were the same.
Signed-off-by: Gautam Menghani <gautam@xxxxxxxxxxxxx>
---
drivers/block/null_blk/main.c | 81 ++++++++++++++-----------------
drivers/block/null_blk/null_blk.h | 5 +-
2 files changed, 39 insertions(+), 47 deletions(-)
diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 3021d58ca51c..692c39479abf 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -705,8 +705,8 @@ static struct nullb_device *null_alloc_dev(void)
dev->init_hctx_fault_config.attr = null_init_hctx_attr;
#endif
- INIT_RADIX_TREE(&dev->data, GFP_ATOMIC);
- INIT_RADIX_TREE(&dev->cache, GFP_ATOMIC);
+ xa_init(&dev->data);
+ xa_init(&dev->cache);
if (badblocks_init(&dev->badblocks, 0)) {
kfree(dev);
return NULL;
@@ -899,18 +899,18 @@ static void null_free_sector(struct nullb *nullb, sector_t sector,
unsigned int sector_bit;
u64 idx;
struct nullb_page *t_page, *ret;
- struct radix_tree_root *root;
+ struct xarray *xa;
- root = is_cache ? &nullb->dev->cache : &nullb->dev->data;
+ xa = is_cache ? &nullb->dev->cache : &nullb->dev->data;
idx = sector >> PAGE_SECTORS_SHIFT;
sector_bit = (sector & SECTOR_MASK);
- t_page = radix_tree_lookup(root, idx);
+ t_page = xa_load(xa, idx);
if (t_page) {
__clear_bit(sector_bit, t_page->bitmap);
if (null_page_empty(t_page)) {
- ret = radix_tree_delete_item(root, idx, t_page);
+ ret = xa_erase(xa, idx);
WARN_ON(ret != t_page);
null_free_page(ret);
if (is_cache)
@@ -919,16 +919,18 @@ static void null_free_sector(struct nullb *nullb, sector_t sector,
}
}
-static struct nullb_page *null_radix_tree_insert(struct nullb *nullb, u64 idx,
+static struct nullb_page *null_xarray_insert(struct nullb *nullb, u64 idx,
struct nullb_page *t_page, bool is_cache)
{
- struct radix_tree_root *root;
+ struct xarray *xa;
+ void *ret;
- root = is_cache ? &nullb->dev->cache : &nullb->dev->data;
+ xa = is_cache ? &nullb->dev->cache : &nullb->dev->data;
- if (radix_tree_insert(root, idx, t_page)) {
+ ret = xa_store(xa, idx, t_page, GFP_ATOMIC);
+ if (xa_is_err(ret)) {
null_free_page(t_page);
- t_page = radix_tree_lookup(root, idx);
+ t_page = xa_load(xa, idx);
WARN_ON(!t_page || t_page->page->index != idx);
} else if (is_cache)
nullb->dev->curr_cache += PAGE_SIZE;
@@ -938,28 +940,16 @@ static struct nullb_page *null_radix_tree_insert(struct nullb *nullb, u64 idx,
static void null_free_device_storage(struct nullb_device *dev, bool is_cache)
{
- unsigned long pos = 0;
- int nr_pages;
- struct nullb_page *ret, *t_pages[FREE_BATCH];
- struct radix_tree_root *root;
-
- root = is_cache ? &dev->cache : &dev->data;
-
- do {
- int i;
-
- nr_pages = radix_tree_gang_lookup(root,
- (void **)t_pages, pos, FREE_BATCH);
-
- for (i = 0; i < nr_pages; i++) {
- pos = t_pages[i]->page->index;
- ret = radix_tree_delete_item(root, pos, t_pages[i]);
- WARN_ON(ret != t_pages[i]);
- null_free_page(ret);
- }
+ unsigned long idx;
+ struct nullb_page *t_page, *ret;
+ struct xarray *xa;
- pos++;
- } while (nr_pages == FREE_BATCH);
+ xa = is_cache ? &dev->cache : &dev->data;
+ xa_for_each(xa, idx, t_page) {
+ ret = xa_erase(xa, idx);
+ WARN_ON(ret != t_page);
+ null_free_page(t_page);
+ }
if (is_cache)
dev->curr_cache = 0;
@@ -971,13 +961,13 @@ static struct nullb_page *__null_lookup_page(struct nullb *nullb,
unsigned int sector_bit;
u64 idx;
struct nullb_page *t_page;
- struct radix_tree_root *root;
+ struct xarray *xa;
idx = sector >> PAGE_SECTORS_SHIFT;
sector_bit = (sector & SECTOR_MASK);
- root = is_cache ? &nullb->dev->cache : &nullb->dev->data;
- t_page = radix_tree_lookup(root, idx);
+ xa = is_cache ? &nullb->dev->cache : &nullb->dev->data;
+ t_page = xa_load(xa, idx);
WARN_ON(t_page && t_page->page->index != idx);
if (t_page && (for_write || test_bit(sector_bit, t_page->bitmap)))
@@ -1005,6 +995,7 @@ static struct nullb_page *null_insert_page(struct nullb *nullb,
{
u64 idx;
struct nullb_page *t_page;
+ struct xarray *xa;
t_page = null_lookup_page(nullb, sector, true, ignore_cache);
if (t_page)
@@ -1016,14 +1007,14 @@ static struct nullb_page *null_insert_page(struct nullb *nullb,
if (!t_page)
goto out_lock;
- if (radix_tree_preload(GFP_NOIO))
+ xa = ignore_cache ? &nullb->dev->data : &nullb->dev->cache;
+ idx = sector >> PAGE_SECTORS_SHIFT;
+ if (xa_is_err(xa_store(xa, idx, NULL, GFP_NOIO)))
goto out_freepage;
spin_lock_irq(&nullb->lock);
- idx = sector >> PAGE_SECTORS_SHIFT;
t_page->page->index = idx;
- t_page = null_radix_tree_insert(nullb, idx, t_page, !ignore_cache);
- radix_tree_preload_end();
+ t_page = null_xarray_insert(nullb, idx, t_page, !ignore_cache);
return t_page;
out_freepage:
@@ -1049,8 +1040,8 @@ static int null_flush_cache_page(struct nullb *nullb, struct nullb_page *c_page)
if (test_bit(NULLB_PAGE_FREE, c_page->bitmap)) {
null_free_page(c_page);
if (t_page && null_page_empty(t_page)) {
- ret = radix_tree_delete_item(&nullb->dev->data,
- idx, t_page);
+ ret = xa_erase(&nullb->dev->data, idx);
+ WARN_ON(ret != t_page);
null_free_page(t_page);
}
return 0;
@@ -1075,7 +1066,7 @@ static int null_flush_cache_page(struct nullb *nullb, struct nullb_page *c_page)
kunmap_local(dst);
kunmap_local(src);
- ret = radix_tree_delete_item(&nullb->dev->cache, idx, c_page);
+ ret = xa_erase(&nullb->dev->cache, idx);
null_free_page(ret);
nullb->dev->curr_cache -= PAGE_SIZE;
@@ -1093,8 +1084,8 @@ static int null_make_cache_space(struct nullb *nullb, unsigned long n)
nullb->dev->curr_cache + n || nullb->dev->curr_cache == 0)
return 0;
- nr_pages = radix_tree_gang_lookup(&nullb->dev->cache,
- (void **)c_pages, nullb->cache_flush_pos, FREE_BATCH);
+ nr_pages = xa_extract(&nullb->dev->cache, (void **)c_pages,
+ nullb->cache_flush_pos, ULONG_MAX, FREE_BATCH, XA_PRESENT);
/*
* nullb_flush_cache_page could unlock before using the c_pages. To
* avoid race, we don't allow page free
@@ -1235,7 +1226,7 @@ static int null_handle_flush(struct nullb *nullb)
break;
}
- WARN_ON(!radix_tree_empty(&nullb->dev->cache));
+ WARN_ON(!xa_empty(&nullb->dev->cache));
spin_unlock_irq(&nullb->lock);
return err;
}
diff --git a/drivers/block/null_blk/null_blk.h b/drivers/block/null_blk/null_blk.h
index 929f659dd255..cc871981edef 100644
--- a/drivers/block/null_blk/null_blk.h
+++ b/drivers/block/null_blk/null_blk.h
@@ -14,6 +14,7 @@
#include <linux/fault-inject.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
+#include <linux/xarray.h>
struct nullb_cmd {
union {
@@ -75,8 +76,8 @@ struct nullb_device {
struct fault_config requeue_config;
struct fault_config init_hctx_fault_config;
#endif
- struct radix_tree_root data; /* data stored in the disk */
- struct radix_tree_root cache; /* disk cache data */
+ struct xarray data; /* data stored in the disk */
+ struct xarray cache; /* disk cache data */
unsigned long flags; /* device flags */
unsigned int curr_cache;
struct badblocks badblocks;
--
2.39.2
