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btrfs-progs: fi usage: fix calculation of chunk size for RAID1/DUP profiles

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Current formula calculates the stripe size, however that's not what we
want in the case of RAID1/DUP profiles. In those cases since chunk are
mirrored across devices we want the full size of the chunk. Without this
patch the 'btrfs fi usage' output from an fs which is using RAID1 is:

	Data,RAID1: Size:2.00GiB, Used:1.00GiB (50.03%)
	   /dev/vdc	   1.00GiB
	   /dev/vdf	   1.00GiB

	Metadata,RAID1: Size:256.00MiB, Used:1.34MiB (0.52%)
	   /dev/vdc	 128.00MiB
	   /dev/vdf	 128.00MiB

	System,RAID1: Size:8.00MiB, Used:16.00KiB (0.20%)
	   /dev/vdc	   4.00MiB
	   /dev/vdf	   4.00MiB

	Unallocated:
	   /dev/vdc	   8.87GiB
	   /dev/vdf	   8.87GiB

So a 2 gigabyte RAID1 chunk actually will take up 4 gigabytes on the
actual disks 2 each. In this case this is being miscalculated as taking
up 1GiB on each device.

This also leads to erroneously calculated unallocated space. The correct
output in this case is:

	Data,RAID1: Size:2.00GiB, Used:1.00GiB (50.03%)
	   /dev/vdc	   2.00GiB
	   /dev/vdf	   2.00GiB

	Metadata,RAID1: Size:256.00MiB, Used:1.34MiB (0.52%)
	   /dev/vdc	 256.00MiB
	   /dev/vdf	 256.00MiB

	System,RAID1: Size:8.00MiB, Used:16.00KiB (0.20%)
	   /dev/vdc	   8.00MiB
	   /dev/vdf	   8.00MiB

	Unallocated:
	   /dev/vdc	   7.74GiB
	   /dev/vdf	   7.74GiB

Fix it by only utilising the chunk formula for profiles which are not
RAID1/DUP.

Issue: #422
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Nikolay Borisov 2021-11-16 16:02:06 +02:00 committed by David Sterba
parent 6df189771d
commit 1b194bb620
1 changed files with 10 additions and 4 deletions
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14
cmds/filesystem-usage.c
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@ -806,11 +806,17 @@ int load_chunk_and_device_info(int fd, struct chunk_info **chunkinfo,
*/
static u64 calc_chunk_size(struct chunk_info *ci)
{
u32 div;
u32 div = 1;
/* No parity + sub_stripes, so order of "-" and "/" does not matter */
div = (ci->num_stripes - btrfs_bg_type_to_nparity(ci->type)) /
btrfs_bg_type_to_sub_stripes(ci->type);
/*
* The formula doesn't work for RAID1/DUP types, we should just return the
* chunk size
*/
if (!(ci->type & (BTRFS_BLOCK_GROUP_RAID1_MASK|BTRFS_BLOCK_GROUP_DUP))) {
/* No parity + sub_stripes, so order of "-" and "/" does not matter */
div = (ci->num_stripes - btrfs_bg_type_to_nparity(ci->type)) /
btrfs_bg_type_to_sub_stripes(ci->type);
}
return ci->size / div;
}