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* btrfs-check finds file extent holes
@ 2016-12-16 23:18 Marc Joliet
  2016-12-17  9:03 ` Marc Joliet
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Marc Joliet @ 2016-12-16 23:18 UTC (permalink / raw)
  To: linux-btrfs

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Hello,

After my backup drive displayed a weird issue (programs accessing it suddenly 
started zombifying, but it worked fine after a reboot), I decided to check the 
file system.  The initial results with btrfs-check's low-memory mode found 
reference count mismatches, but that seems to have been a false positive, 
since btrfs-check's normal mode does not find them.  Instead, it complains 
about several file extent holes:

# btrfs check /dev/sdd2       
Checking filesystem on /dev/sdd2
UUID: f97b3cda-15e8-418b-bb9b-235391ef2a38
checking extents
checking free space cache
checking fs roots
root 30634 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 30635 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 30636 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 30657 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 30746 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 30747 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 30764 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 30834 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 30835 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 30915 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 30916 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 30942 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 31038 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 31053 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 31366 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 31367 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 31368 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 31385 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 31425 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 31473 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 31499 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 31554 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 31572 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 31606 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 31653 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096
root 31680 inode 95066 errors 100, file extent discount
Found file extent holes:
        start: 413696, len: 4096

(The check is still not done, it's been running for about 24 hours now.)

Is this something that btrfs-check can safely repair, or that is perhaps even 
harmless?

% uname -a
Linux thetick 4.8.14-gentoo #1 SMP PREEMPT Sun Dec 11 17:09:09 CET 2016 x86_64 
AMD Athlon(tm) 64 X2 Dual Core Processor 4200+ AuthenticAMD GNU/Linux
% /sbin/btrfs --version
btrfs-progs v4.8.5

I can't show any other output because btrfs-check is still running.  I can 
only say that the file system is 1TB large and about 88% full (fuller than 
normal, which is about 85%).

Greetings
-- 
Marc Joliet
--
"People who think they know everything really annoy those of us who know we
don't" - Bjarne Stroustrup

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^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-12-19 11:12 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2016-12-16 23:18 btrfs-check finds file extent holes Marc Joliet
2016-12-17  9:03 ` Marc Joliet
2016-12-17 10:00 ` Marc Joliet
2016-12-19 11:12 ` Marc Joliet

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