| commit | ec9ef7a13be4dcce964c8503e8999087945e5b9e | |
| author | Li Zefan <lizf@cn.fujitsu.com> | |
| Thu, 1 Dec 2011 06:06:42 +0000 (1 14:06 +0800) | ||
| committer | Li Zefan <lizf@cn.fujitsu.com> | |
| Wed, 11 Jan 2012 02:26:46 +0000 (11 10:26 +0800) | ||
| tree | afd97976c76c45fca7b659f8d81cbcd4995d2a7e | treesnapshot (tar.gz zip) |
| parent | de11cc12df17337979e0929d2831887432f236ca | commitdiff |
Btrfs: simplfy calculation of stripe length for discard operation
For btrfs raid, while discarding a range of space, we'll need to know
the start offset and length to discard for each device, and it's done
in btrfs_map_block().
However the calculation is a bit complex for raid0 and raid10, so I
reimplement it based on a fact that:
dev1 dev2 dev3 (raid0)
-----------------------------------
s0 s3 s6 s1 s4 s7 s2 s5
Each device has (total_stripes / nr_dev) stripes, or plus one.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
For btrfs raid, while discarding a range of space, we'll need to know
the start offset and length to discard for each device, and it's done
in btrfs_map_block().
However the calculation is a bit complex for raid0 and raid10, so I
reimplement it based on a fact that:
dev1 dev2 dev3 (raid0)
-----------------------------------
s0 s3 s6 s1 s4 s7 s2 s5
Each device has (total_stripes / nr_dev) stripes, or plus one.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
| fs/btrfs/volumes.c | diffblobblamehistory |