From 2c4580454fffbf184fdb9292aa19ab1ffc224add Mon Sep 17 00:00:00 2001 From: Zhao Lei Date: Thu, 16 Jul 2015 15:00:46 +0800 Subject: [PATCH] btrfs: Cleanup for btrfs_calc_num_tolerated_disk_barrier_failures 1: Use ARRAY_SIZE(types) to replace a static-value variant: int num_types = 4; 2: Use 'continue' on condition to reduce one level tab if (!XXX) { code; ... } -> if (XXX) continue; code; ... 3: Put setting 'num_tolerated_disk_barrier_failures = 2' to (num_tolerated_disk_barrier_failures > 2) condition to make make logic neat. if (num_tolerated_disk_barrier_failures > 0 && XXX) num_tolerated_disk_barrier_failures = 0; else if (num_tolerated_disk_barrier_failures > 1) { if (XXX) num_tolerated_disk_barrier_failures = 1; else if (XXX) num_tolerated_disk_barrier_failures = 2; -> if (num_tolerated_disk_barrier_failures > 0 && XXX) num_tolerated_disk_barrier_failures = 0; if (num_tolerated_disk_barrier_failures > 1 && XXX) num_tolerated_disk_barrier_failures = ; if (num_tolerated_disk_barrier_failures > 2 && XXX) num_tolerated_disk_barrier_failures = 2; 4: Remove comment of: num_mirrors - 1: if RAID1 or RAID10 is configured and more than 2 mirrors are used. which is not fit with code. Signed-off-by: Zhao Lei Signed-off-by: Chris Mason --- fs/btrfs/disk-io.c | 73 +++++++++++++++++++++------------------------- 1 file changed, 33 insertions(+), 40 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index cc15514b4a76..51192d94c90c 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3449,13 +3449,12 @@ int btrfs_calc_num_tolerated_disk_barrier_failures( BTRFS_BLOCK_GROUP_SYSTEM, BTRFS_BLOCK_GROUP_METADATA, BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA}; - int num_types = 4; int i; int c; int num_tolerated_disk_barrier_failures = (int)fs_info->fs_devices->num_devices; - for (i = 0; i < num_types; i++) { + for (i = 0; i < ARRAY_SIZE(types); i++) { struct btrfs_space_info *tmp; sinfo = NULL; @@ -3473,44 +3472,38 @@ int btrfs_calc_num_tolerated_disk_barrier_failures( down_read(&sinfo->groups_sem); for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) { - if (!list_empty(&sinfo->block_groups[c])) { - u64 flags; - - btrfs_get_block_group_info( - &sinfo->block_groups[c], &space); - if (space.total_bytes == 0 || - space.used_bytes == 0) - continue; - flags = space.flags; - /* - * return - * 0: if dup, single or RAID0 is configured for - * any of metadata, system or data, else - * 1: if RAID5 is configured, or if RAID1 or - * RAID10 is configured and only two mirrors - * are used, else - * 2: if RAID6 is configured, else - * num_mirrors - 1: if RAID1 or RAID10 is - * configured and more than - * 2 mirrors are used. - */ - if (num_tolerated_disk_barrier_failures > 0 && - ((flags & (BTRFS_BLOCK_GROUP_DUP | - BTRFS_BLOCK_GROUP_RAID0)) || - ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) - == 0))) - num_tolerated_disk_barrier_failures = 0; - else if (num_tolerated_disk_barrier_failures > 1) { - if (flags & (BTRFS_BLOCK_GROUP_RAID1 | - BTRFS_BLOCK_GROUP_RAID5 | - BTRFS_BLOCK_GROUP_RAID10)) { - num_tolerated_disk_barrier_failures = 1; - } else if (flags & - BTRFS_BLOCK_GROUP_RAID6) { - num_tolerated_disk_barrier_failures = 2; - } - } - } + u64 flags; + + if (list_empty(&sinfo->block_groups[c])) + continue; + + btrfs_get_block_group_info(&sinfo->block_groups[c], + &space); + if (space.total_bytes == 0 || space.used_bytes == 0) + continue; + flags = space.flags; + /* + * return + * 0: if dup, single or RAID0 is configured for + * any of metadata, system or data, else + * 1: if RAID5 is configured, or if RAID1 or + * RAID10 is configured and only two mirrors + * are used, else + * 2: if RAID6 is configured + */ + if (num_tolerated_disk_barrier_failures > 0 && + ((flags & (BTRFS_BLOCK_GROUP_DUP | + BTRFS_BLOCK_GROUP_RAID0)) || + ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0))) + num_tolerated_disk_barrier_failures = 0; + else if (num_tolerated_disk_barrier_failures > 1 && + (flags & (BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID5 | + BTRFS_BLOCK_GROUP_RAID10))) + num_tolerated_disk_barrier_failures = 1; + else if (num_tolerated_disk_barrier_failures > 2 && + (flags & BTRFS_BLOCK_GROUP_RAID6)) + num_tolerated_disk_barrier_failures = 2; } up_read(&sinfo->groups_sem); } -- 2.20.1