Currently sctx->stat.last_physical only got updated in the following
cases:
- When the last stripe of a non-RAID56 chunk is scrubbed
This implies a pitfall, if the last stripe is at the chunk boundary,
and we finished the scrub of the whole chunk, we won't update
last_physical at all until the next chunk.
- When a P/Q stripe of a RAID56 chunk is scrubbed
This leads the following two problems:
- sctx->stat.last_physical is not updated for a almost full chunk
This is especially bad, affecting scrub resume, as the resume would
start from last_physical, causing unnecessary re-scrub.
- "btrfs scrub status" will not report any progress for a long time
Fix the problem by properly updating @last_physical after each stripe is
scrubbed.
And since we're here, for the sake of consistency, use spin lock to
protect the update of @last_physical, just like all the remaining
call sites touching sctx->stat.
Reported-by: Michel Palleau <michel.palleau@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CAMFk-+igFTv2E8svg=cQ6o3e6CrR5QwgQ3Ok9EyRaEvvthpqCQ@mail.gmail.com/
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
63447b7dd4