4.16-stable review patch. If anyone has any objections, please let me know.
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From: Ming Lei ming.lei@redhat.com
[ Upstream commit 66231ad3e2886ba99fbf440cea44cab547e5163f ]
On ARM64, the default page size has been 64K on some distributions, and we should allow ARM64 people to play null_blk.
This patch fixes the issue by extend page bitmap size for supporting other non-4KB PAGE_SIZE.
Cc: Bart Van Assche Bart.VanAssche@wdc.com Cc: Shaohua Li shli@kernel.org Cc: Kyungchan Koh kkc6196@fb.com, Cc: weiping zhang zhangweiping@didichuxing.com Cc: Yi Zhang yi.zhang@redhat.com Reported-by: Yi Zhang yi.zhang@redhat.com Signed-off-by: Ming Lei ming.lei@redhat.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/block/null_blk.c | 46 +++++++++++++++++++++++++--------------------- 1 file changed, 25 insertions(+), 21 deletions(-)
--- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -72,6 +72,7 @@ enum nullb_device_flags { NULLB_DEV_FL_CACHE = 3, };
+#define MAP_SZ ((PAGE_SIZE >> SECTOR_SHIFT) + 2) /* * nullb_page is a page in memory for nullb devices. * @@ -86,10 +87,10 @@ enum nullb_device_flags { */ struct nullb_page { struct page *page; - unsigned long bitmap; + DECLARE_BITMAP(bitmap, MAP_SZ); }; -#define NULLB_PAGE_LOCK (sizeof(unsigned long) * 8 - 1) -#define NULLB_PAGE_FREE (sizeof(unsigned long) * 8 - 2) +#define NULLB_PAGE_LOCK (MAP_SZ - 1) +#define NULLB_PAGE_FREE (MAP_SZ - 2)
struct nullb_device { struct nullb *nullb; @@ -728,7 +729,7 @@ static struct nullb_page *null_alloc_pag if (!t_page->page) goto out_freepage;
- t_page->bitmap = 0; + memset(t_page->bitmap, 0, sizeof(t_page->bitmap)); return t_page; out_freepage: kfree(t_page); @@ -738,13 +739,20 @@ out:
static void null_free_page(struct nullb_page *t_page) { - __set_bit(NULLB_PAGE_FREE, &t_page->bitmap); - if (test_bit(NULLB_PAGE_LOCK, &t_page->bitmap)) + __set_bit(NULLB_PAGE_FREE, t_page->bitmap); + if (test_bit(NULLB_PAGE_LOCK, t_page->bitmap)) return; __free_page(t_page->page); kfree(t_page); }
+static bool null_page_empty(struct nullb_page *page) +{ + int size = MAP_SZ - 2; + + return find_first_bit(page->bitmap, size) == size; +} + static void null_free_sector(struct nullb *nullb, sector_t sector, bool is_cache) { @@ -759,9 +767,9 @@ static void null_free_sector(struct null
t_page = radix_tree_lookup(root, idx); if (t_page) { - __clear_bit(sector_bit, &t_page->bitmap); + __clear_bit(sector_bit, t_page->bitmap);
- if (!t_page->bitmap) { + if (null_page_empty(t_page)) { ret = radix_tree_delete_item(root, idx, t_page); WARN_ON(ret != t_page); null_free_page(ret); @@ -832,7 +840,7 @@ static struct nullb_page *__null_lookup_ t_page = radix_tree_lookup(root, idx); WARN_ON(t_page && t_page->page->index != idx);
- if (t_page && (for_write || test_bit(sector_bit, &t_page->bitmap))) + if (t_page && (for_write || test_bit(sector_bit, t_page->bitmap))) return t_page;
return NULL; @@ -895,10 +903,10 @@ static int null_flush_cache_page(struct
t_page = null_insert_page(nullb, idx << PAGE_SECTORS_SHIFT, true);
- __clear_bit(NULLB_PAGE_LOCK, &c_page->bitmap); - if (test_bit(NULLB_PAGE_FREE, &c_page->bitmap)) { + __clear_bit(NULLB_PAGE_LOCK, c_page->bitmap); + if (test_bit(NULLB_PAGE_FREE, c_page->bitmap)) { null_free_page(c_page); - if (t_page && t_page->bitmap == 0) { + if (t_page && null_page_empty(t_page)) { ret = radix_tree_delete_item(&nullb->dev->data, idx, t_page); null_free_page(t_page); @@ -914,11 +922,11 @@ static int null_flush_cache_page(struct
for (i = 0; i < PAGE_SECTORS; i += (nullb->dev->blocksize >> SECTOR_SHIFT)) { - if (test_bit(i, &c_page->bitmap)) { + if (test_bit(i, c_page->bitmap)) { offset = (i << SECTOR_SHIFT); memcpy(dst + offset, src + offset, nullb->dev->blocksize); - __set_bit(i, &t_page->bitmap); + __set_bit(i, t_page->bitmap); } }
@@ -955,10 +963,10 @@ again: * We found the page which is being flushed to disk by other * threads */ - if (test_bit(NULLB_PAGE_LOCK, &c_pages[i]->bitmap)) + if (test_bit(NULLB_PAGE_LOCK, c_pages[i]->bitmap)) c_pages[i] = NULL; else - __set_bit(NULLB_PAGE_LOCK, &c_pages[i]->bitmap); + __set_bit(NULLB_PAGE_LOCK, c_pages[i]->bitmap); }
one_round = 0; @@ -1011,7 +1019,7 @@ static int copy_to_nullb(struct nullb *n kunmap_atomic(dst); kunmap_atomic(src);
- __set_bit(sector & SECTOR_MASK, &t_page->bitmap); + __set_bit(sector & SECTOR_MASK, t_page->bitmap);
if (is_fua) null_free_sector(nullb, sector, true); @@ -1802,10 +1810,6 @@ static int __init null_init(void) struct nullb *nullb; struct nullb_device *dev;
- /* check for nullb_page.bitmap */ - if (sizeof(unsigned long) * 8 - 2 < (PAGE_SIZE >> SECTOR_SHIFT)) - return -EINVAL; - if (g_bs > PAGE_SIZE) { pr_warn("null_blk: invalid block size\n"); pr_warn("null_blk: defaults block size to %lu\n", PAGE_SIZE);