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btrfs: Cleanup for btrfs_calc_num_tolerated_disk_barrier_failures

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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 <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
This commit is contained in:
Zhao Lei 2015-07-16 15:00:46 +08:00 committed by Chris Mason
parent 8c204c9657
commit 2c4580454f
1 changed files with 32 additions and 39 deletions
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71
fs/btrfs/disk-io.c
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@ -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;
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;
}
}
}
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);
}