Hi All,
I found a bug in mkfs.btrfs, when it is used the option '-r'. It seems that it is not visible the full disk. $ uname -a Linux venice.bhome 4.12.8 #268 SMP Thu Aug 17 09:03:26 CEST 2017 x86_64 GNU/Linux $ btrfs --version btrfs-progs v4.12 --- First try without '-r' (/dev/sda is about 80GB) $ sudo mkfs.btrfs -f /dev/sda4 btrfs-progs v4.12 See http://btrfs.wiki.kernel.org for more information. Label: (null) UUID: 6f11971d-a945-4f33-8750-c16a7438a15d Node size: 16384 Sector size: 4096 Filesystem size: 83.73GiB Block group profiles: Data: single 8.00MiB Metadata: DUP 1.00GiB System: DUP 8.00MiB SSD detected: no Incompat features: extref, skinny-metadata Number of devices: 1 Devices: ID SIZE PATH 1 83.73GiB /dev/sda4 All the disk (~80GB) is visible ---- Now try with '-r' $ sudo mkfs.btrfs -r /tmp/test/ -f /dev/sda4 btrfs-progs v4.12 See http://btrfs.wiki.kernel.org for more information. Making image is completed. Label: (null) UUID: 60ea1c38-e5b1-403d-8a25-1cac2258922d Node size: 16384 Sector size: 4096 Filesystem size: 52.00MiB Block group profiles: Data: single 29.19MiB Metadata: DUP 5.19MiB System: DUP 4.00MiB SSD detected: no Incompat features: extref, skinny-metadata Number of devices: 1 Devices: ID SIZE PATH 1 52.00MiB /dev/sda4 where /tmp/test contains: $ ls -l /tmp/test/ total 16392 -rw-r--r-- 1 ghigo ghigo 5 Aug 31 18:26 123 -rw-r--r-- 1 ghigo ghigo 16777216 Aug 31 18:26 123456 -rw-r--r-- 1 ghigo ghigo 5 Aug 31 18:26 456 BTRFS sees only 52MB instead of ~80GB. Even if I try to mount and umount, the thing doesn't change. $ sudo mount /dev/sda4 /mnt/other/ $ echo 123 | sudo tee /mnt/other/9999 123 $ sync $ sudo umount /mnt/other $ sudo mount /dev/sda4 /mnt/other/ Below an output of "btrfs fi us" $ sudo btrfs fi us /mnt/other/ Overall: Device size: 52.00MiB Device allocated: 52.00MiB Device unallocated: 0.00B Device missing: 0.00B Used: 16.16MiB Free (estimated): 13.19MiB (min: 13.19MiB) Data ratio: 1.00 Metadata ratio: 1.00 Global reserve: 16.00MiB (used: 0.00B) Data,single: Size:29.19MiB, Used:16.00MiB /dev/sda4 29.19MiB Metadata,single: Size:18.81MiB, Used:144.00KiB /dev/sda4 18.81MiB System,single: Size:4.00MiB, Used:16.00KiB /dev/sda4 4.00MiB Unallocated: /dev/sda4 0.00B And a balance is impossible $ sudo btrfs bala start --full-balance /mnt/other/ ERROR: error during balancing '/mnt/other/': No space left on device There may be more info in syslog - try dmesg | tail $ dmesg | tail [ 2034.684649] BTRFS: device fsid 60ea1c38-e5b1-403d-8a25-1cac2258922d devid 1 transid 7 /dev/sda4 [ 2140.835629] BTRFS info (device sda4): disk space caching is enabled [ 2140.835632] BTRFS info (device sda4): has skinny extents [ 2140.835633] BTRFS info (device sda4): flagging fs with big metadata feature [ 2140.837381] BTRFS info (device sda4): creating UUID tree [ 2171.646349] BTRFS info (device sda4): disk space caching is enabled [ 2171.646362] BTRFS info (device sda4): has skinny extents [ 2273.696914] BTRFS info (device sda4): relocating block group 20512768 flags data [ 2273.721995] BTRFS info (device sda4): relocating block group 9633792 flags data [ 2273.746950] BTRFS info (device sda4): 6 enospc errors during balance I tried several btrfs-progs version ( I go back until v0.20-rc1: 2012!!!), and the behavior is the same: with '-r' the disk is not fully used. So I suppose that it is a kernel problem (IIRC the kernel should "complete" the mkfs at the first mount). Any idea ? BR G.Baroncelli -- gpg @keyserver.linux.it: Goffredo Baroncelli <kreijackATinwind.it> Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
