[LU-4796] NOT inject OBD_FAIL_FID_LOOKUP failure on dotdot entry

• Type: Bug
• Resolution: Fixed
• Priority: Blocker
• Fix Version/s: Lustre 2.6.0
• Affects Version/s: Lustre 2.6.0
• Severity: 3
• Assignee: nasf (Inactive)
• Reporter: nasf (Inactive)

Description

The LFSCK may cannot rebuild the FID-in-dirent for ".." entry after the MDT restored from file-level backup, because there is not enough space in the directory head area. Then OBD_FAIL_FID_LOOKUP failed on ".." will cause unexpected failure. For example:

== sanity-lfsck test 5: LFSCK can handle IFIG object upgrading == 06:53:16 (1395237196)
rm: cannot remove `/mnt/lustre/d4.sanity-lfsck': Directory not empty
CMD: shadow-8vm12 /usr/sbin/lctl set_param fail_loc=0x1504
fail_loc=0x1504
...