tree 060a03b7ad726216243bcebfc84878be0c43f6c7
parent 03679ade86b2b1c370c8790f1ffcbcdef6d49f9f
author Omar Sandoval <osandov@fb.com> 1434739969 -0700
committer Chris Mason <clm@fb.com> 1439130866 -0700

Btrfs: count devices correctly in readahead during RAID 5/6 replace

Commit 5fbc7c59fd22 ("Btrfs: fix unfinished readahead thread for raid5/6
degraded mounting") fixed a problem where we would skip a missing device
when we shouldn't have because there are no other mirrors to read from
in RAID 5/6. After commit 2c8cdd6ee4e7 ("Btrfs, replace: write dirty
pages into the replace target device"), the fix doesn't work when we're
doing a missing device replace on RAID 5/6 because the replace device is
counted as a mirror so we're tricked into thinking we can safely skip
the missing device. The fix is to count only the real stripes and decide
based on that.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>