Bug 533569
| Summary: | nfs4: two directories may have identical st_dev and st_ino | ||
|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | Jim Meyering <meyering> |
| Component: | kernel | Assignee: | Jeff Layton <jlayton> |
| Status: | CLOSED WONTFIX | QA Contact: | Fedora Extras Quality Assurance <extras-qa> |
| Severity: | medium | Docs Contact: | |
| Priority: | high | ||
| Version: | rawhide | CC: | dougsland, eblake, gansalmon, itamar, jlayton, kdudka, kernel-maint, meyering, nfs-maint, rwheeler, steved, tjn |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2012-10-18 15:29:02 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
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Description
Jim Meyering
2009-11-07 11:52:48 UTC
> # stat --printf "%d %i %n\n" /tmp/mnt{,$top} > 22 2 /tmp/mnt > 22 2 /tmp/mnt/home I do see this... but > $ du /tmp/mnt > /dev/null > du: WARNING: Circular directory structure. > This almost certainly means that you have a corrupted file system. > NOTIFY YOUR SYSTEM MANAGER. > The following directory is part of the cycle: > `/tmp/mnt/home' What kernel are you using and nfs-utils I meant to say... I don't see the du error... what kernel/nfs-utils are you using.. (In reply to comment #2) > I meant to say... I don't see the du error... what kernel/nfs-utils are > you using.. You need to compile GNU coreutils from git to see the error. Hi Steve, kernel version is listed above. nfs-utils-1.2.0-18.fc12.x86_64 I think I understand what the issue is here. I just don't think that there's much we can do about it... The stat program is doing a lstat() and that doesn't trigger a submount (LOOKUP_FOLLOW isn't set). So we end up doing a GETATTR call that returns info on the root inode of the /home mount. So the stat() syscall gets the "real" st_ino of /tmp/mnt/home, but the st_dev is still that of the parent (/tmp/mnt). This is particularly evident here because the root of any ext3/4 filesystem has an st_ino of 2. I think our options are: 1) fix the kernel to trigger a submount even when LOOKUP_FOLLOW isn't set (quite possibly very hard on performance) 2) fix the kernel to return a bit more info when we have a "potential mountpoint" like this. My suggestion on LKML was to coopt a new st_mode/i_mode bit and use that to indicate that a directory is potentially a new mountpoint if someone were to walk into it So far, my suggestion hasn't received any feedback upstream. This bug appears to have been reported against 'rawhide' during the Fedora 12 development cycle. Changing version to '12'. More information and reason for this action is here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping AFAIK, nothing has changed, so I've reset "Version:" to rawhide. This bug appears to have been reported against 'rawhide' during the Fedora 13 development cycle. Changing version to '13'. More information and reason for this action is here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping Still affects rawhide, too. This bug appears to have been reported against 'rawhide' during the Fedora 14 development cycle. Changing version to '14'. More information and reason for this action is here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping Changing version back to 'rawhide'. Is this something that we can change in upstream or should we close this out? Not much we can do, I don't think... If anything, the automount semantics are even less likely to trigger a mount these days. I think the only hope for this problem is the xstat() work that dhowells was working on, but that has sort of died upstream. I'll go ahead and close this WONTFIX for now. Please reopen it if you want to discuss it further. |