On 10/3/2017 2:11 PM, Hugo Mills wrote:
Hi, Stephen,
On Tue, Oct 03, 2017 at 08:52:04PM +0000, Stephen Nesbitt wrote:
Here it i. There are a couple of out-of-order entries beginning at 117. And
yes I did uncover a bad stick of RAM:
btrfs-progs v4.9.1
leaf 2589782867968 items 134 free space 6753 generation 3351574 owner 2
fs uuid 24b768c3-2141-44bf-ae93-1c3833c8c8e3
chunk uuid 19ce12f0-d271-46b8-a691-e0d26c1790c6
[snip]
item 116 key (1623012749312 EXTENT_ITEM 45056) itemoff 10908 itemsize 53
extent refs 1 gen 3346444 flags DATA
extent data backref root 271 objectid 24999978 offset 0 count 1
item 117 key (1621939052544 EXTENT_ITEM 8192) itemoff 10855 itemsize 53
extent refs 1 gen 3346495 flags DATA
extent data backref root 271 objectid 21751764 offset 6733824 count 1
item 118 key (1623012450304 EXTENT_ITEM 8192) itemoff 10802 itemsize 53
extent refs 1 gen 3351513 flags DATA
extent data backref root 271 objectid 5724364 offset 680640512 count 1
item 119 key (1623012802560 EXTENT_ITEM 12288) itemoff 10749 itemsize 53
extent refs 1 gen 3346376 flags DATA
extent data backref root 271 objectid 21751764 offset 6701056 count 1
hex(1623012749312)
'0x179e3193000'
hex(1621939052544)
'0x179a319e000'
hex(1623012450304)
'0x179e314a000'
hex(1623012802560)
'0x179e31a0000'
That's "e" -> "a" in the fourth hex digit, which is a single-bit
flip, and should be fixable by btrfs check (I think). However, even
fixing that, it's not ordered, because 118 is then before 117, which
could be another bitflip ("9" -> "4" in the 7th digit), but two bad
bits that close to each other seems unlikely to me.
Hugo.
Hope this is a duplicate reply - I might have fat fingered something.
The underlying file is disposable/replaceable. Any way to zero out/zap
the bad BTRFS entry?
-steve
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
