LinuxLists.cc - [PATCH] nfsd: Fix error cleanup path in nfsd

2024-03-18 16:32:24

Subject: [PATCH] nfsd: Fix error cleanup path in nfsd_rename()

Commit a8b0026847b8 ("rename(): avoid a deadlock in the case of parents
having no common ancestor") added an error bail out path. However this
path does not drop the remount protection that has been acquired. Fix
the cleanup path to properly drop the remount protection.

Fixes: a8b0026847b8 ("rename(): avoid a deadlock in the case of parents having no common ancestor")
Signed-off-by: Jan Kara <[email protected]>
---
fs/nfsd/vfs.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 6a9464262fae..2e41eb4c3cec 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1852,7 +1852,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
trap = lock_rename(tdentry, fdentry);
if (IS_ERR(trap)) {
err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
- goto out;
+ goto out_want_write;
}
err = fh_fill_pre_attrs(ffhp);
if (err != nfs_ok)
@@ -1922,6 +1922,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
}
out_unlock:
unlock_rename(tdentry, fdentry);
+out_want_write:
fh_drop_write(ffhp);

/*
--
2.35.3

2024-03-18 17:00:14

by Jeffrey Layton

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Subject: Re: [PATCH] nfsd: Fix error cleanup path in nfsd_rename()

On Mon, 2024-03-18 at 17:32 +0100, Jan Kara wrote:
> Commit a8b0026847b8 ("rename(): avoid a deadlock in the case of parents
> having no common ancestor") added an error bail out path. However this
> path does not drop the remount protection that has been acquired. Fix
> the cleanup path to properly drop the remount protection.
>
> Fixes: a8b0026847b8 ("rename(): avoid a deadlock in the case of parents having no common ancestor")
> Signed-off-by: Jan Kara <[email protected]>
> ---
> fs/nfsd/vfs.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
> index 6a9464262fae..2e41eb4c3cec 100644
> --- a/fs/nfsd/vfs.c
> +++ b/fs/nfsd/vfs.c
> @@ -1852,7 +1852,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
> trap = lock_rename(tdentry, fdentry);
> if (IS_ERR(trap)) {
> err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
> - goto out;
> + goto out_want_write;
> }
> err = fh_fill_pre_attrs(ffhp);
> if (err != nfs_ok)
> @@ -1922,6 +1922,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
> }
> out_unlock:
> unlock_rename(tdentry, fdentry);
> +out_want_write:
> fh_drop_write(ffhp);
>
> /*

Nice catch.

Reviewed-by: Jeff Layton <[email protected]>

2024-03-18 20:12:37

by Chuck Lever

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Subject: Re: [PATCH] nfsd: Fix error cleanup path in nfsd_rename()

On Mon, Mar 18, 2024 at 05:32:09PM +0100, Jan Kara wrote:
> Commit a8b0026847b8 ("rename(): avoid a deadlock in the case of parents
> having no common ancestor") added an error bail out path. However this
> path does not drop the remount protection that has been acquired. Fix
> the cleanup path to properly drop the remount protection.
>
> Fixes: a8b0026847b8 ("rename(): avoid a deadlock in the case of parents having no common ancestor")
> Signed-off-by: Jan Kara <[email protected]>

Al, Jan, let me know if you'd like me to take this through the
nfsd tree for v6.9-rc. If not:

Acked-by: Chuck Lever <[email protected]>

> ---
> fs/nfsd/vfs.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
> index 6a9464262fae..2e41eb4c3cec 100644
> --- a/fs/nfsd/vfs.c
> +++ b/fs/nfsd/vfs.c
> @@ -1852,7 +1852,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
> trap = lock_rename(tdentry, fdentry);
> if (IS_ERR(trap)) {
> err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
> - goto out;
> + goto out_want_write;
> }
> err = fh_fill_pre_attrs(ffhp);
> if (err != nfs_ok)
> @@ -1922,6 +1922,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
> }
> out_unlock:
> unlock_rename(tdentry, fdentry);
> +out_want_write:
> fh_drop_write(ffhp);
>
> /*
> --
> 2.35.3
>

--
Chuck Lever

2024-03-19 13:54:05

by Jan Kara

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Subject: Re: [PATCH] nfsd: Fix error cleanup path in nfsd_rename()

On Mon 18-03-24 16:12:17, Chuck Lever wrote:
> On Mon, Mar 18, 2024 at 05:32:09PM +0100, Jan Kara wrote:
> > Commit a8b0026847b8 ("rename(): avoid a deadlock in the case of parents
> > having no common ancestor") added an error bail out path. However this
> > path does not drop the remount protection that has been acquired. Fix
> > the cleanup path to properly drop the remount protection.
> >
> > Fixes: a8b0026847b8 ("rename(): avoid a deadlock in the case of parents having no common ancestor")
> > Signed-off-by: Jan Kara <[email protected]>
>
> Al, Jan, let me know if you'd like me to take this through the
> nfsd tree for v6.9-rc. If not:
>
> Acked-by: Chuck Lever <[email protected]>

Yeah, I guess taking this through NFS tree is the best.

Honza

>
>
> > ---
> > fs/nfsd/vfs.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
> > index 6a9464262fae..2e41eb4c3cec 100644
> > --- a/fs/nfsd/vfs.c
> > +++ b/fs/nfsd/vfs.c
> > @@ -1852,7 +1852,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
> > trap = lock_rename(tdentry, fdentry);
> > if (IS_ERR(trap)) {
> > err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
> > - goto out;
> > + goto out_want_write;
> > }
> > err = fh_fill_pre_attrs(ffhp);
> > if (err != nfs_ok)
> > @@ -1922,6 +1922,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
> > }
> > out_unlock:
> > unlock_rename(tdentry, fdentry);
> > +out_want_write:
> > fh_drop_write(ffhp);
> >
> > /*
> > --
> > 2.35.3
> >
>
> --
> Chuck Lever
>
--
Jan Kara <[email protected]>
SUSE Labs, CR

2024-03-19 15:18:39

by Chuck Lever

[permalink] [raw]

Subject: Re: [PATCH] nfsd: Fix error cleanup path in nfsd_rename()

On Tue, Mar 19, 2024 at 02:53:54PM +0100, Jan Kara wrote:
> On Mon 18-03-24 16:12:17, Chuck Lever wrote:
> > On Mon, Mar 18, 2024 at 05:32:09PM +0100, Jan Kara wrote:
> > > Commit a8b0026847b8 ("rename(): avoid a deadlock in the case of parents
> > > having no common ancestor") added an error bail out path. However this
> > > path does not drop the remount protection that has been acquired. Fix
> > > the cleanup path to properly drop the remount protection.
> > >
> > > Fixes: a8b0026847b8 ("rename(): avoid a deadlock in the case of parents having no common ancestor")
> > > Signed-off-by: Jan Kara <[email protected]>
> >
> > Al, Jan, let me know if you'd like me to take this through the
> > nfsd tree for v6.9-rc. If not:
> >
> > Acked-by: Chuck Lever <[email protected]>
>
> Yeah, I guess taking this through NFS tree is the best.

I've pushed this to my nfsd-fixes branch, and will begin testing.

> Honza
>
> >
> >
> > > ---
> > > fs/nfsd/vfs.c | 3 ++-
> > > 1 file changed, 2 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
> > > index 6a9464262fae..2e41eb4c3cec 100644
> > > --- a/fs/nfsd/vfs.c
> > > +++ b/fs/nfsd/vfs.c
> > > @@ -1852,7 +1852,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
> > > trap = lock_rename(tdentry, fdentry);
> > > if (IS_ERR(trap)) {
> > > err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
> > > - goto out;
> > > + goto out_want_write;
> > > }
> > > err = fh_fill_pre_attrs(ffhp);
> > > if (err != nfs_ok)
> > > @@ -1922,6 +1922,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
> > > }
> > > out_unlock:
> > > unlock_rename(tdentry, fdentry);
> > > +out_want_write:
> > > fh_drop_write(ffhp);
> > >
> > > /*
> > > --
> > > 2.35.3
> > >
> >
> > --
> > Chuck Lever
> >
> --
> Jan Kara <[email protected]>
> SUSE Labs, CR

--
Chuck Lever

2024-03-22 02:38:09

by Al Viro

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