Btrfs: improve the loop of scrub_stripe
1) Right now scrub_stripe() is looping in some unnecessary cases: * when the found extent item's objectid has been out of the dev extent's range but we haven't finish scanning all the range within the dev extent * when all the items has been processed but we haven't finish scanning all the range within the dev extent In both cases, we can just finish the loop to save costs. 2) Besides, when the found extent item's length is larger than the stripe len(64k), we don't have to release the path and search again as it'll get at the same key used in the last loop, we can instead increase the logical cursor in place till all space of the extent is scanned. 3) And we use 0 as the key's offset to search btree, then get to previous item to find a smaller item, and again have to move to the next one to get the right item. Setting offset=-1 and previous_item() is the correct way. 4) As we won't find any checksum at offset unless this 'offset' is in a data extent, we can just find checksum when we're really going to scrub an extent. Signed-off-by:Liu Bo <bo.li.liu@oracle.com> Signed-off-by:
Josef Bacik <jbacik@fusionio.com>
parent
55793c0d
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