While one partition is busy, reformat another partition from the command
line. Afterwards parted/libparted still detects the original file
system and GParted shows errors from the file system specific tools
reporting the new file system doesn't exist. Only limitation is that
the new new file system must be recognised by libparted (or by GParted's
fallback file system signature detection).
Case #1, File system reformatting:
# parted /dev/sdb print
Model: ATA SAMSUNG SSD UM41 (scsi)
Disk /dev/sdb: 8012MB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Number Start End Size Type File system Flags
1 1049kB 2149MB 2147MB primary ext2
2 2149MB 4296MB 2147MB primary ext2
# mount | fgrep sdb
/dev/sdb1 on /mnt/1 type ext2 (rw)
# mkfs.xfs -f /dev/sdb2
# blkid /dev/sdb2
/dev/sdb2: UUID="c31823a2-b81b-46fa-8246-0a59695e4834" TYPE="xfs"
# parted /dev/sdb print
Model: ATA SAMSUNG SSD UM41 (scsi)
Disk /dev/sdb: 8012MB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Number Start End Size Type File system Flags
1 1049kB 2149MB 2147MB primary ext2
2 2149MB 4296MB 2147MB primary ext2
# e2label /dev/sdb2
e2label: Bad magic number in super-block while trying to open /dev/sdb2
Couldn't find valid filesystem superblock.
# dumpe2fs /dev/sdb2
dumpe2fs 1.41.12 (17-May-2010)
dumpe2fs: Bad magic number in super-block while trying to open /dev/sdb2
Couldn't find valid filesystem superblock.
Case #2, Removing device from multi-device btrfs:
# btrfs filesystem show /dev/sdb1
Label: none uuid: a05db434-efd5-4e8c-902f-05f89a88b610
Total devices 2 FS bytes used 156.00KB
devid 2 size 2.00GB used 512.00MB path /dev/sdb2
devid 1 size 2.00GB used 240.75MB path /dev/sdb1
# mount /dev/sdb1 /mnt/1
# btrfs device delete /dev/sdb2
# btrfs filesystem show /dev/sdb1
Label: none uuid: a05db434-efd5-4e8c-902f-05f89a88b610
Total devices 1 FS bytes used 92.00KB
devid 1 size 2.00GB used 714.25MB path /dev/sdb1
# btrfs filesystem show /dev/sdb2
and GParted reports this error for partition /dev/sdb2:
Unable to read the contents of this file system!
Because of this some operations may be unavailable.
The cause might be a missing software package.
The following list of software packages is required for btrfs
file system support: btrfs-tools.
This is another case of libparted reading from the whole disk device
(/dev/sdb) yet the file system tools use the partition specific block
device (/dev/sdb2), and the Linux buffer cache not providing cache
coherency. Previous scenario was fixed with:
797f0b8eeb
Flush device after wiping a file system (#688882)
This affects libparted 2.0 to 3.1 inclusive and is fixed by:
http://git.savannah.gnu.org/cgit/parted.git/commit/?id=fb99ba5ebd0dc34204fc9f1014131d5d494805bc
Revert "linux-commit: do not unnecessarily open partition device nodes"
Fix by calling ped_device_sync() to guarantee cache coherency for each
device during scanning.
Bug #723842 - GParted resizes the wrong filesystem (does not pass the
devid to btrfs filesystem resize)
3bea067596