[LU-13690] lfs mirror ... /mnt/lustre/.lustre/fid/$FID causes CWARN() about invalid FID formats

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.14.0
• Severity: 3
• Assignee: John Hammond
• Reporter: John Hammond

Description

lfs mirror creates a volatile file in the .lustre/fid directory using llapi_create_volatile_param(). That function tries to unlink the volatile file just creates (in case the server does not support volatile files). The unlink causes obf_lookup() to print a warning on the console:

k:~# echo XXX > /mnt/lustre/f0
k:~# lfs path2fid /mnt/lustre/f0
[0x200000401:0x1:0x0]
k:~# lctl pool_new lustre.ddn_ssd
Pool lustre.ddn_ssd created
k:~# lctl pool_new lustre.ddn_hdd
Pool lustre.ddn_hdd created
k:~# lctl pool_add lustre.ddn_ssd lustre-OST0000
OST lustre-OST0000_UUID added to pool lustre.ddn_ssd
k:~# lctl pool_add lustre.ddn_hdd lustre-OST0001
OST lustre-OST0001_UUID added to pool lustre.ddn_hdd
k:~# dmesg -c > /dev/null
k:~# strace -o strace.out lfs mirror extend -N -p ddn_ssd '/mnt/lustre/.lustre/fid/[0x200000401:0x1:0x0]'
k:~# dmesg 
[62872.916981] Lustre: 31074:0:(mdd_device.c:776:obf_lookup()) lustre-MDD0000: Trying to lookup invalid FID [.
                                                                                                              :VOLATILE:0000:4CC14F53] in .lustre/fid, FID format should be [0x200000400:0x1:0x0]

This is too noisy when 'lfs mirror' is called for lots of file by FID.