Problem occurs with 3.19.0-0.rc7.git0.1.fc22.x86_64, no regression testing or attempt to reproduce has been done yet. But the file system isn't particularly old. Steps 1-6 occur with kernel 3.16 through 3.19 with no errors. 1. mkfs.btrfs -draid1 -mraid1 /dev/sd[bc] ## btrfs-progs ~3.16 or 3.17 2. mount /dev/sdb /mnt/btr 3. copy some files to /mnt/btr 4. unmount /mnt/btr 5. Disconnect /dev/sdc Steps 6-10 occur only with kernel 3.19 6. mount -odegraded /dev/sdb /mnt/btr 7. btrfs balance start -dconvert=single -mconvert=single -f /mnt/btr 8. In another shell, btrfs balance pause /mnt/btr 9. Wait for pause confirmation in 1st shell, then umount /mnt/btr 10. mount -odegraded /dev/sdb /mnt/btr -msingle=dup was disallowed so I chose single [ 2029.715092] BTRFS error (device sdc): unable to start balance with target metadata profile 32 Result when mounting: [39691.150313] BTRFS info (device sdb): allowing degraded mounts [39691.152501] BTRFS info (device sdb): disk space caching is enabled [39693.756987] BTRFS: too many missing devices, writeable mount is not allowed [39693.778349] BTRFS: open_ctree failed I have no reason to think this is a regression, but haven't tried older kernels yet. Additional information: [ 5719.840900] BTRFS info (device sdc): found 16 extents [ 6097.761142] usb 1-1.4: USB disconnect, device number 4 [ 6097.774052] sd 3:0:0:0: [sdc] Synchronizing SCSI cache [ 6097.783575] sd 3:0:0:0: [sdc] Synchronize Cache(10) failed: Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK 5719 is about the time of the balance pause. I don't know the meaning of the last two messages or their implication in possibly causing the problem. [root@f22s ~]# btrfs check /dev/sdb warning, device 2 is missing warning devid 2 not found already Checking filesystem on /dev/sdb UUID: 0f1c615f-30a0-4166-8a3c-987849551513 checking extents checking free space cache Error reading 476011409408, -1 failed to load free space cache for block group 476368076800 checking fs roots checking csums checking root refs found 164679408219 bytes used err is 0 total csum bytes: 354762924 total tree bytes: 608239616 total fs tree bytes: 139395072 total extent tree bytes: 58785792 btree space waste bytes: 84024816 file data blocks allocated: 378008100864 referenced 385864163328 Btrfs v3.18.2 No change with -orecovery,degraded; -oro,degraded does mount. btrfs-image -c9 -t4 uses 100% CPU and hangs indefinitely, 353MB image here: https://drive.google.com/file/d/0B_2Asp8DGjJ9b2p0aUpGUTVzVU0/view?pli=1 bug report for writeable mount fail is here, includes dmesg https://bugzilla.kernel.org/show_bug.cgi?id=92641 separate bug report for btrfs-image hang (includes strace), here https://bugzilla.kernel.org/show_bug.cgi?id=92651 -- Chris Murphy -- 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
