The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 370345b4bd184a49ac68d6591801e5e3605b355a # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025040850-carwash-detention-d475@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 370345b4bd184a49ac68d6591801e5e3605b355a Mon Sep 17 00:00:00 2001 From: Chuck Lever chuck.lever@oracle.com Date: Sun, 26 Jan 2025 16:50:18 -0500 Subject: [PATCH] NFSD: Never return NFS4ERR_FILE_OPEN when removing a directory

RFC 8881 Section 18.25.4 paragraph 5 tells us that the server should return NFS4ERR_FILE_OPEN only if the target object is an opened file. This suggests that returning this status when removing a directory will confuse NFS clients.

This is a version-specific issue; nfsd_proc_remove/rmdir() and nfsd3_proc_remove/rmdir() already return nfserr_access as appropriate.

Unfortunately there is no quick way for nfsd4_remove() to determine whether the target object is a file or not, so the check is done in in nfsd_unlink() for now.

Reported-by: Trond Myklebust trondmy@hammerspace.com Fixes: 466e16f0920f ("nfsd: check for EBUSY from vfs_rmdir/vfs_unink.") Reviewed-by: Jeff Layton jlayton@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Chuck Lever chuck.lever@oracle.com

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 749dd84bdb41..4e0a2c0549c7 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1930,9 +1930,17 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, return err; }

-/* - * Unlink a file or directory - * N.B. After this call fhp needs an fh_put +/** + * nfsd_unlink - remove a directory entry + * @rqstp: RPC transaction context + * @fhp: the file handle of the parent directory to be modified + * @type: enforced file type of the object to be removed + * @fname: the name of directory entry to be removed + * @flen: length of @fname in octets + * + * After this call fhp needs an fh_put. + * + * Returns a generic NFS status code in network byte-order. */ __be32 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, @@ -2006,10 +2014,14 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, fh_drop_write(fhp); out_nfserr: if (host_err == -EBUSY) { - /* name is mounted-on. There is no perfect - * error status. + /* + * See RFC 8881 Section 18.25.4 para 4: NFSv4 REMOVE + * wants a status unique to the object type. */ - err = nfserr_file_open; + if (type != S_IFDIR) + err = nfserr_file_open; + else + err = nfserr_acces; } out: return err != nfs_ok ? err : nfserrno(host_err);