From 2b108268006e06d57ec9810f4ccf5d99d7e5b598 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Mon, 6 Apr 2015 07:48:20 -0700 Subject: [PATCH] Btrfs: don't use highmem for free space cache pages In order to create the free space cache concurrently with FS modifications, we need to take a few block group locks. The cache code also does kmap, which would schedule with the locks held. Instead of going through kmap_atomic, lets just use lowmem for the cache pages. Signed-off-by: Chris Mason --- fs/btrfs/free-space-cache.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index 6886ae063483..83532a245947 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -85,7 +85,8 @@ static struct inode *__lookup_free_space_inode(struct btrfs_root *root, } mapping_set_gfp_mask(inode->i_mapping, - mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS); + mapping_gfp_mask(inode->i_mapping) & + ~(GFP_NOFS & ~__GFP_HIGHMEM)); return inode; } @@ -310,7 +311,6 @@ static void io_ctl_free(struct btrfs_io_ctl *io_ctl) static void io_ctl_unmap_page(struct btrfs_io_ctl *io_ctl) { if (io_ctl->cur) { - kunmap(io_ctl->page); io_ctl->cur = NULL; io_ctl->orig = NULL; } @@ -320,7 +320,7 @@ static void io_ctl_map_page(struct btrfs_io_ctl *io_ctl, int clear) { ASSERT(io_ctl->index < io_ctl->num_pages); io_ctl->page = io_ctl->pages[io_ctl->index++]; - io_ctl->cur = kmap(io_ctl->page); + io_ctl->cur = page_address(io_ctl->page); io_ctl->orig = io_ctl->cur; io_ctl->size = PAGE_CACHE_SIZE; if (clear) @@ -446,10 +446,9 @@ static void io_ctl_set_crc(struct btrfs_io_ctl *io_ctl, int index) PAGE_CACHE_SIZE - offset); btrfs_csum_final(crc, (char *)&crc); io_ctl_unmap_page(io_ctl); - tmp = kmap(io_ctl->pages[0]); + tmp = page_address(io_ctl->pages[0]); tmp += index; *tmp = crc; - kunmap(io_ctl->pages[0]); } static int io_ctl_check_crc(struct btrfs_io_ctl *io_ctl, int index) @@ -466,10 +465,9 @@ static int io_ctl_check_crc(struct btrfs_io_ctl *io_ctl, int index) if (index == 0) offset = sizeof(u32) * io_ctl->num_pages; - tmp = kmap(io_ctl->pages[0]); + tmp = page_address(io_ctl->pages[0]); tmp += index; val = *tmp; - kunmap(io_ctl->pages[0]); io_ctl_map_page(io_ctl, 0); crc = btrfs_csum_data(io_ctl->orig + offset, crc, -- 2.20.1