In the null_blk for different page and sector calculation we have simple macros to make the code more redable.
Similar to that this is a purely code cleanup patch where we introduce two new macros for calculating the page index from given sector and index (offset) of the sector in the page. Signed-off-by: Chaitanya Kulkarni <[email protected]> --- drivers/block/null_blk_main.c | 37 ++++++++++++++++++++--------------- 1 file changed, 21 insertions(+), 16 deletions(-) diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c index fca011a05277..d463bde001b6 100644 --- a/drivers/block/null_blk_main.c +++ b/drivers/block/null_blk_main.c @@ -16,6 +16,11 @@ #define PAGE_SECTORS (1 << PAGE_SECTORS_SHIFT) #define SECTOR_MASK (PAGE_SECTORS - 1) +/* Gives page index for which this sector belongs to. */ +#define PAGE_IDX_FROM_SECT(sect) (sect >> PAGE_SECTORS_SHIFT) +/* Gives index (offset) of the sector within page. */ +#define SECT_IDX_IN_PAGE(sect) ((sect & SECTOR_MASK) << SECTOR_SHIFT) + #define FREE_BATCH 16 #define TICKS_PER_SEC 50ULL @@ -708,20 +713,20 @@ static void null_free_sector(struct nullb *nullb, sector_t sector, struct radix_tree_root *root; root = is_cache ? &nullb->dev->cache : &nullb->dev->data; - idx = sector >> PAGE_SECTORS_SHIFT; + idx = PAGE_IDX_FROM_SECT(sector); sector_bit = (sector & SECTOR_MASK); t_page = radix_tree_lookup(root, 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); - WARN_ON(ret != t_page); - null_free_page(ret); - if (is_cache) - nullb->dev->curr_cache -= PAGE_SIZE; - } + if (!t_page) + return; + __clear_bit(sector_bit, 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); + if (is_cache) + nullb->dev->curr_cache -= PAGE_SIZE; } } @@ -733,11 +738,11 @@ static void null_zero_sector(struct nullb_device *d, sector_t sect, unsigned int offset; void *dest; - t_page = radix_tree_lookup(root, sect >> PAGE_SECTORS_SHIFT); + t_page = radix_tree_lookup(root, PAGE_IDX_FROM_SECT(sect)); if (!t_page) return; - offset = (sect & SECTOR_MASK) << SECTOR_SHIFT; + offset = SECT_IDX_IN_PAGE(sect); dest = kmap_atomic(t_page->page); memset(dest + offset, 0, SECTOR_SIZE * nr_sects); kunmap_atomic(dest); @@ -797,7 +802,7 @@ static struct nullb_page *__null_lookup_page(struct nullb *nullb, struct nullb_page *t_page; struct radix_tree_root *root; - idx = sector >> PAGE_SECTORS_SHIFT; + idx = PAGE_IDX_FROM_SECT(sector); sector_bit = (sector & SECTOR_MASK); root = is_cache ? &nullb->dev->cache : &nullb->dev->data; @@ -973,7 +978,7 @@ static int copy_to_nullb(struct nullb *nullb, struct page *source, if (null_cache_active(nullb) && !is_fua) null_make_cache_space(nullb, PAGE_SIZE); - offset = (sector & SECTOR_MASK) << SECTOR_SHIFT; + offset = SECT_IDX_IN_PAGE(sector); t_page = null_insert_page(nullb, sector, !null_cache_active(nullb) || is_fua); if (!t_page) @@ -1007,7 +1012,7 @@ static int copy_from_nullb(struct nullb *nullb, struct page *dest, while (count < n) { temp = min_t(size_t, nullb->dev->blocksize, n - count); - offset = (sector & SECTOR_MASK) << SECTOR_SHIFT; + offset = SECT_IDX_IN_PAGE(sector); t_page = null_lookup_page(nullb, sector, false, !null_cache_active(nullb)); -- 2.17.0
