我正在使用 Btrfs 3.12，每次删除快照时，整个 btrfs 卷都会变为“只读”。因此我将其卸载并尝试
btrfsck --repair
但每次它都会在这一行失败：
Extent back ref already exists for 4788162379776 parent 0 root 258
Extent back ref already exists for 4788162789376 parent 0 root 258
Abandon (core dumped)
这是 dsmeg 的结果（因为有很多，所以是最后几行）
scsi 6:0:0:0: Direct-Access EQLOGIC 100E-00 7.0 PQ: 0 ANSI: 5
sd 5:0:0:0: Attached scsi generic sg9 type 0
sd 6:0:0:0: Attached scsi generic sg10 type 0
sd 5:0:0:0: [sde] 2684355840 4096-byte logical blocks: (10.9 TB/10.0 TiB)
sd 6:0:0:0: [sdf] 2684355840 4096-byte logical blocks: (10.9 TB/10.0 TiB)
sd 10:0:0:0: [sdd] Write Protect is off
sd 10:0:0:0: [sdd] Mode Sense: 81 00 00 00
sd 9:0:0:0: [sdc] Write Protect is off
sd 9:0:0:0: [sdc] Mode Sense: 81 00 00 00
sd 10:0:0:0: [sdd] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
sd 9:0:0:0: [sdc] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
sd 6:0:0:0: [sdf] Write Protect is off
sd 6:0:0:0: [sdf] Mode Sense: 81 00 00 00
sd 5:0:0:0: [sde] Write Protect is off
sd 5:0:0:0: [sde] Mode Sense: 81 00 00 00
sd 6:0:0:0: [sdf] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
sd 9:0:0:0: [sdc] 2684355840 4096-byte logical blocks: (10.9 TB/10.0 TiB)
sd 5:0:0:0: [sde] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
sd 10:0:0:0: [sdd] 2684355840 4096-byte logical blocks: (10.9 TB/10.0 TiB)
sd 5:0:0:0: [sde] 2684355840 4096-byte logical blocks: (10.9 TB/10.0 TiB)
sd 6:0:0:0: [sdf] 2684355840 4096-byte logical blocks: (10.9 TB/10.0 TiB)
scsi 7:0:0:0: Direct-Access EQLOGIC 100E-00 7.0 PQ: 0 ANSI: 5
sd 7:0:0:0: Attached scsi generic sg11 type 0
sd 7:0:0:0: [sdg] 348967680 4096-byte logical blocks: (1.42 TB/1.29 TiB)
scsi 8:0:0:0: Direct-Access EQLOGIC 100E-00 7.0 PQ: 0 ANSI: 5
sd 8:0:0:0: Attached scsi generic sg12 type 0
sd 7:0:0:0: [sdg] Write Protect is off
sd 7:0:0:0: [sdg] Mode Sense: 81 00 00 00
sd 7:0:0:0: [sdg] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
sd 8:0:0:0: [sdh] 348967680 4096-byte logical blocks: (1.42 TB/1.29 TiB)
sd 7:0:0:0: [sdg] 348967680 4096-byte logical blocks: (1.42 TB/1.29 TiB)
sd 8:0:0:0: [sdh] Write Protect is off
sd 8:0:0:0: [sdh] Mode Sense: 81 00 00 00
sd 8:0:0:0: [sdh] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
sd 8:0:0:0: [sdh] 348967680 4096-byte logical blocks: (1.42 TB/1.29 TiB)
sdg: sdg1
sdh: sdh1
sd 8:0:0:0: [sdh] 348967680 4096-byte logical blocks: (1.42 TB/1.29 TiB)
sd 7:0:0:0: [sdg] 348967680 4096-byte logical blocks: (1.42 TB/1.29 TiB)
sd 8:0:0:0: [sdh] Attached SCSI disk
sd 7:0:0:0: [sdg] Attached SCSI disk
sde: unknown partition table
sdf: unknown partition table
sd 5:0:0:0: [sde] 2684355840 4096-byte logical blocks: (10.9 TB/10.0 TiB)
sd 6:0:0:0: [sdf] 2684355840 4096-byte logical blocks: (10.9 TB/10.0 TiB)
sd 5:0:0:0: [sde] Attached SCSI disk
sd 6:0:0:0: [sdf] Attached SCSI disk
sdd: unknown partition table
sdc: unknown partition table
sd 9:0:0:0: [sdc] 2684355840 4096-byte logical blocks: (10.9 TB/10.0 TiB)
sd 10:0:0:0: [sdd] 2684355840 4096-byte logical blocks: (10.9 TB/10.0 TiB)
sd 9:0:0:0: [sdc] Attached SCSI disk
sd 10:0:0:0: [sdd] Attached SCSI disk
device-mapper: multipath round-robin: version 1.0.0 loaded
bio: create slab <bio-2> at 2
bio: create slab <bio-3> at 3
btrfs: device fsid dd26758b-a689-46a8-b4da-b5ecc07d73b6 devid 1 transid 135638 /dev/dm-0
btrfs: device fsid dd26758b-a689-46a8-b4da-b5ecc07d73b6 devid 2 transid 135638 /dev/dm-1
btrfs: device fsid dd26758b-a689-46a8-b4da-b5ecc07d73b6 devid 2 transid 135638 /dev/dm-1
btrfs: device fsid dd26758b-a689-46a8-b4da-b5ecc07d73b6 devid 1 transid 135638 /dev/dm-0
btrfs: device fsid dd26758b-a689-46a8-b4da-b5ecc07d73b6 devid 2 transid 135638 /dev/dm-1
perf samples too long (2511 > 2500), lowering kernel.perf_event_max_sample_rate to 50000
show_signal_msg: 81 callbacks suppressed
btrfsck[2604]: segfault at 0 ip 000000000041243a sp 00007fffe6793e40 error 6 in btrfsck[400000+53000]
我还发现了一个文件：/var/crash/_sbin_btrfsck.0.crash 以下是行的末尾：
7f127eb34000-7f127eb36000 rw-p 00000000 00:00 0
7f127eb36000-7f127eb37000 r--p 00022000 08:11 5374145 /lib/x86_64-linux-gnu/ld-2.15.so
7f127eb37000-7f127eb39000 rw-p 00023000 08:11 5374145 /lib/x86_64-linux-gnu/ld-2.15.so
7fffd36b4000-7fffd36d5000 rw-p 00000000 00:00 0 [stack]
7fffd378c000-7fffd378e000 r-xp 00000000 00:00 0 [vdso]
ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall]
ProcStatus:
Name: btrfsck
State: S (sleeping)
Tgid: 9512
Ngid: 0
Pid: 9512
PPid: 5436
TracerPid: 0
Uid: 0 0 0 0
Gid: 0 0 0 0
FDSize: 256
Groups: 0
VmPeak: 8855944 kB
VmSize: 8855944 kB
VmLck: 0 kB
VmPin: 0 kB
VmHWM: 7644076 kB
VmRSS: 7432256 kB
VmData: 8835640 kB
VmStk: 136 kB
VmExe: 332 kB
VmLib: 3364 kB
VmPTE: 17324 kB
VmSwap: 1404244 kB
Threads: 1
SigQ: 1/63594
SigPnd: 0000000000000000
ShdPnd: 0000000000000000
SigBlk: 0000000000000000
SigIgn: 0000000000000000
SigCgt: 0000000180000000
CapInh: 0000000000000000
CapPrm: 0000001fffffffff
CapEff: 0000001fffffffff
CapBnd: 0000001fffffffff
Seccomp: 0
Cpus_allowed: ffffffff
Cpus_allowed_list: 0-31
Mems_allowed: 00000000,00000001
Mems_allowed_list: 0
voluntary_ctxt_switches: 77639
nonvoluntary_ctxt_switches: 377681
Signal: 6
Uname: Linux 3.13.0-031300-generic x86_64
问候，
答案1
您遇到了两个问题，它们不一定互相关联。
- 每次我删除快照时，整个 btrfs 卷都会变成“只读”。
dmesg没有提供任何有关该方面的线索。
btrfsck --repair因信号 6 而崩溃（如 .crash 文件中所述）
这是一个错误。