[Gluster-devel] (no subject)

[Anand Avati]

Emmanuel,
The Linux FUSE does not perform lookup() on ".." but instead looks up the
parent of cwd's dentry within the kernel module itself. In 3.3 we changed
the behavior to establish inode on a ".." lookup but neglect dentry
establishment (since it will form a loop). You might want to
backport 9bd1b291e3e107250b38d05702df7cd751382bdc to release-3.2 if NetBSD
FUSE sends ".." lookup.

Avati

On Wed, Aug 8, 2012 at 9:51 PM, Emmanuel Dreyfus <manu at netbsd.org> wrote:

> Hi
>
> Test case: calling getcwd(3) in a directory on NetBSD
> - glusterfs release-3.3 has no problem
> - glusterfs 3.2.7 has a funny bug when a node TTL is expired *and* if
> the getcwd program is stored in the glusterfs volume.
>
> # cd /gfs/manu/bugB4 && /gfs/manu/getcwd/getcwd && sleep 2 && \
>   /gfs/manu/getcwd/getcwd
> getcwd = "/gfs/manu/bugB4"
> getcwd = "(null)"
>
> # cd /gfs/manu/bugB4 && /tmp/getcwd && sleep 2 && /tmp/getcwd
> getcwd = "/gfs/manu/bugB4"
> getcwd = "/gfs/manu/bugB4"
>
> When it fails the client logs say:
> [2012-08-09 06:45:37.338851] W [inode.c:180:__foreach_ancestor_dentry]
>     0-: per dentry fn returned 1
> [2012-08-09 06:45:37.339021] C [inode.c:232:__is_dentry_cyclic]
>     0-gfs/inode: detected cyclic loop formation during inode linkage.
>     inode (-5514238854638478444/20958215-feaa-4648-acde-5f3e8da776e5) l
>     linking under itself as ..
> [2012-08-09 06:45:37.339112] W [inode.c:844:inode_lookup]  0-: inode
>     not found
>
> Is that a bug in glusterfs 3.2.7 or an inaccuracy in NetBSD FUSE? Here
> is getcwd sources for anyone willing to test:
>
> /* cc -o getcwd getcwd.c */
> #include <unistd.h>
> #include <stdio.h>
> #include <sys/param.h>
>
> int
> main(void)
> {
>         char buf[MAXPATHLEN + 1];
>
>         (void)printf("getcwd = \"%s\"\n", getcwd(buf, MAXPATHLEN));
>
>         return 0;
> }
>
> --
> Emmanuel Dreyfus
> http://hcpnet.free.fr/pubz
> manu at netbsd.org
>
> _______________________________________________
> Gluster-devel mailing list
> Gluster-devel at nongnu.org
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>
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