[LU-5836] Error "Device or resource busy" after attempting release of file cleared from 'dirty'

• Type: Bug
• Resolution: Unresolved
• Priority: Minor
• Affects Version/s: Lustre 2.5.2
• Labels: HSM patch
• Environment: CentOS 6
• Severity: 3

Epic

client server

• Project: HSM
• Assignee: WC Triage
• Reporter: Andrew Moe (Inactive)

Description

I can consistently replicate this error message.

# Write a file
$ dd if=/dev/zero of=file01 bs=1M count=1
1+0 records in
1+0 records out
1048576 bytes (1.0 MB) copied, 0.00335841 s, 312 MB/s

# Archive the file
$ sudo lfs hsm_archive file01

# Wait for file to archive 

# Write to file to make it 'dirty'
$ echo "0" >> file01

# Clear the dirty state
$ lfs hsm_clear --dirty file01

# Attempt to release the file
$ sudo lfs hsm_release file02
Cannot send HSM request (use of file02): Device or resource busy

I suppose it might make sense that a file should not be released if it is truly dirty. But the error message does not seem to be appropriate. Perhaps it should not even be possible to clear a 'dirty' state

This is a comment from another person I've consulted on this:

The error comes from the MDT:

00000004:20000000:0.0:1414607590.182318:0:1585:0:(mdt_open.c:2042:mdt_hsm_release()) [0x2000013c2:0x116c3:0x0] data_version mismatches: packed=4313503196 and on-disk=4313503194

so it doesn't set the OBD_MD_FLRELEASED bit, and the client in turn returns EBUSY.

No idea what that means though.