From 7d8d35791b1b87a503ebe1f2f48407ee05dbaf5e Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Fri, 15 Mar 2024 18:12:09 +0000 Subject: brd: Remove use of page->index This debugging check will become more costly in the future when we shrink struct page. It has not proven to be useful, so simply remove it. This lets us use __xa_insert instead of __xa_cmpxchg() as we no longer need to know about the page that is currently stored in the XArray. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Hannes Reinecke Reviewed-by: Keith Busch Link: https://lore.kernel.org/r/20240315181212.2573753-1-willy@infradead.org Signed-off-by: Jens Axboe --- drivers/block/brd.c | 40 +++++++++++----------------------------- 1 file changed, 11 insertions(+), 29 deletions(-) (limited to 'drivers/block/brd.c') diff --git a/drivers/block/brd.c b/drivers/block/brd.c index e322cef6596b..b900fe9e0030 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -29,10 +29,7 @@ /* * Each block ramdisk device has a xarray brd_pages of pages that stores - * the pages containing the block device's contents. A brd page's ->index is - * its offset in PAGE_SIZE units. This is similar to, but in no way connected - * with, the kernel's pagecache or buffer cache (which sit above our block - * device). + * the pages containing the block device's contents. */ struct brd_device { int brd_number; @@ -51,15 +48,7 @@ struct brd_device { */ static struct page *brd_lookup_page(struct brd_device *brd, sector_t sector) { - pgoff_t idx; - struct page *page; - - idx = sector >> PAGE_SECTORS_SHIFT; /* sector to page index */ - page = xa_load(&brd->brd_pages, idx); - - BUG_ON(page && page->index != idx); - - return page; + return xa_load(&brd->brd_pages, sector >> PAGE_SECTORS_SHIFT); } /* @@ -67,8 +56,8 @@ static struct page *brd_lookup_page(struct brd_device *brd, sector_t sector) */ static int brd_insert_page(struct brd_device *brd, sector_t sector, gfp_t gfp) { - pgoff_t idx; - struct page *page, *cur; + pgoff_t idx = sector >> PAGE_SECTORS_SHIFT; + struct page *page; int ret = 0; page = brd_lookup_page(brd, sector); @@ -80,23 +69,16 @@ static int brd_insert_page(struct brd_device *brd, sector_t sector, gfp_t gfp) return -ENOMEM; xa_lock(&brd->brd_pages); - - idx = sector >> PAGE_SECTORS_SHIFT; - page->index = idx; - - cur = __xa_cmpxchg(&brd->brd_pages, idx, NULL, page, gfp); - - if (unlikely(cur)) { - __free_page(page); - ret = xa_err(cur); - if (!ret && (cur->index != idx)) - ret = -EIO; - } else { + ret = __xa_insert(&brd->brd_pages, idx, page, gfp); + if (!ret) brd->brd_nr_pages++; - } - xa_unlock(&brd->brd_pages); + if (ret < 0) { + __free_page(page); + if (ret == -EBUSY) + ret = 0; + } return ret; } -- cgit v1.2.3-70-g09d2