Ensure that d_off is initialized
ClosedPublic
Actions

Authored by markj on Dec 28 2020, 12:39 AM.

Details

Reviewers

kib
trasz

Commits

rG90f580b95409: Ensure that dirent's d_off field is initialized

Summary

We have the d_off field in struct dirent for providing the offset of the
next directory entry. Several filesystems did not populate the field,
which ends up being leaked.

Reported by: Syed Faraz Abrar <faraz@elttam.com>

Diff Detail

Repository

rG FreeBSD src repository

Lint

Lint Not Applicable

Unit

Tests Not Applicable

Event Timeline

markj created this revision.Dec 28 2020, 12:39 AM

Herald added a subscriber: imp. · View Herald TranscriptDec 28 2020, 12:39 AM

Harbormaster completed remote builds in B35721: Diff 81244.Dec 28 2020, 12:39 AM

markj requested review of this revision.Dec 28 2020, 12:39 AM

markj added reviewers: kib, trasz.Dec 28 2020, 12:42 AM

kib accepted this revision.Dec 28 2020, 8:03 PM

This revision is now accepted and ready to land.Dec 28 2020, 8:03 PM

I don't remember much about how directory entries work, but I don't see anything wrong with the patch. I have a question, though: how did it work before? Is that field actually used?

d_off was added during ino64 work, for supposed benefit of nfs server. I believe the idea was that d_off use could replace cookies.

Right now it is not used, and d_off presence is optional. If d_off is zero, userspace has to use other methods (lseek ?) to bookmark directory position.

Closed by commit rG90f580b95409: Ensure that dirent's d_off field is initialized (authored by markj). · Explain WhyJan 3 2021, 4:51 PM

This revision was automatically updated to reflect the committed changes.

markj added a commit: rG90f580b95409: Ensure that dirent's d_off field is initialized.