From 80cc83842394e5ad3e93487359106aab3420bcb7 Mon Sep 17 00:00:00 2001 From: Ira Weiny Date: Tue, 9 Feb 2021 22:22:20 -0800 Subject: btrfs: use copy_highpage() instead of 2 kmaps() There are many places where kmap/memove/kunmap patterns occur. This pattern exists in the core common function copy_highpage(). Use copy_highpage to avoid open coding the use of kmap and leverages the core functions use of kmap_local_page(). Development of this patch was aided by the following coccinelle script: // // SPDX-License-Identifier: GPL-2.0-only // Find kmap/copypage/kunmap pattern and replace with copy_highpage calls // // NOTE: The expressions in the copy page version of this kmap pattern are // overly complex and so these all need individual attention. // // Confidence: Low // Copyright: (C) 2021 Intel Corporation // URL: http://coccinelle.lip6.fr/ // Comments: // Options: // // Then a copy_page where we have 2 pages involved. // @ copy_page_rule @ expression page, page2, To, From, Size; identifier ptr, ptr2; type VP, VP2; @@ /* kmap */ ( -VP ptr = kmap(page); ... -VP2 ptr2 = kmap(page2); | -VP ptr = kmap_atomic(page); ... -VP2 ptr2 = kmap_atomic(page2); | -ptr = kmap(page); ... -ptr2 = kmap(page2); | -ptr = kmap_atomic(page); ... -ptr2 = kmap_atomic(page2); ) // 1 or more copy versions of the entire page <+... ( -copy_page(To, From); +copy_highpage(To, From); | -memmove(To, From, Size); +memmoveExtra(To, From, Size); ) ...+> /* kunmap */ ( -kunmap(page2); ... -kunmap(page); | -kunmap(page); ... -kunmap(page2); | -kmap_atomic(ptr2); ... -kmap_atomic(ptr); ) // Remove any pointers left unused @ depends on copy_page_rule @ identifier copy_page_rule.ptr; identifier copy_page_rule.ptr2; type VP, VP1; type VP2, VP21; @@ -VP ptr; ... when != ptr; ? VP1 ptr; -VP2 ptr2; ... when != ptr2; ? VP21 ptr2; // Reviewed-by: Christoph Hellwig Signed-off-by: Ira Weiny Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/raid56.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c index 93fbf87bdc8d..c86aff9c7daa 100644 --- a/fs/btrfs/raid56.c +++ b/fs/btrfs/raid56.c @@ -250,8 +250,6 @@ int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info) static void cache_rbio_pages(struct btrfs_raid_bio *rbio) { int i; - char *s; - char *d; int ret; ret = alloc_rbio_pages(rbio); @@ -262,13 +260,7 @@ static void cache_rbio_pages(struct btrfs_raid_bio *rbio) if (!rbio->bio_pages[i]) continue; - s = kmap(rbio->bio_pages[i]); - d = kmap(rbio->stripe_pages[i]); - - copy_page(d, s); - - kunmap(rbio->bio_pages[i]); - kunmap(rbio->stripe_pages[i]); + copy_highpage(rbio->stripe_pages[i], rbio->bio_pages[i]); SetPageUptodate(rbio->stripe_pages[i]); } set_bit(RBIO_CACHE_READY_BIT, &rbio->flags); -- cgit v1.2.3