[LU-15486] FLR: mirroring a non-mirrored file in a directory with default FLR layout fails

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.16.0
• Affects Version/s: Lustre 2.12.8
• Labels: LTS15
• Severity: 3
• Epic Link: FLR tech debt review
• Assignee: Zhenyu Xu
• Reporter: Andreas Dilger

Description

If a file does not have a mirror in a directory with a default FLR mirror, then running "lfs mirror extend" on the file fails with "cannot create volatile file: Invalid argument".

A non-striped file can be created in a directory with a default FLR layout, for example, if a new file is created with "O_APPEND" (LU-9341) and uses the mdt.*.append_* parameters to create the file layout, or if a non-mirrored file is renamed into a directory with a default FLR layout.

# mkdir $DIR/$tdir
# lfs setstripe -N -c 1 -i 0 -N -c 1 -i 1 $DIR/$tdir
# echo $tfile >> $DIR/$tdir/$tfile.append
# lfs getstripe -N $DIR/$tdir/$tfile.append

# lfs mirror extend -N -c 1 -i 2 $DIR/$tdir/$tfile.append
lfs mirror extend: /mnt/testfs/d2/f2.append: cannot create volatile file: Invalid argument

It appears that the problem might relate to the "lfs mirror extend" volatile file inheriting the FLR layout from the parent directory but then confusing the logic later and causing the extend operation to fail. Hard-linking the file into a non-FLR parent directory allows the "lfs mirror extend" to create a mirror on the file:

# mkdir $DIR/$tdir.tmp
# lfs setstripe -d $DIR/$tdir.tmp
# ln $DIR/$tdir/$tfile-append $DIR/$tdir.tmp/$tfile.tmp
# lfs mirror extend -N -c 1 -i 2 $DIR/$tdir.tmp/$tfile.tmp
# rm $DIR/$tdir.tmp/$tfile.tmp
# lfs getstripe -N $DIR/$tdir/$tfile.append
2

Issue Links

• is duplicated by: LU-18042 sanity-flr test_0k interop: mirror extend failed - cannot create volatile file: Invalid argument