The patch below does not apply to the 5.15-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-5.15.y git checkout FETCH_HEAD git cherry-pick -x b01f21cacde9f2878492cf318fee61bf4ccad323 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025081556-hazard-eccentric-fcb9@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

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

From b01f21cacde9f2878492cf318fee61bf4ccad323 Mon Sep 17 00:00:00 2001 From: Trond Myklebust trond.myklebust@hammerspace.com Date: Sun, 3 Aug 2025 14:31:59 -0700 Subject: [PATCH] NFS: Fix the setting of capabilities when automounting a new filesystem

Capabilities cannot be inherited when we cross into a new filesystem. They need to be reset to the minimal defaults, and then probed for again.

Fixes: 54ceac451598 ("NFS: Share NFS superblocks per-protocol per-server per-FSID") Cc: stable@vger.kernel.org Reviewed-by: Benjamin Coddington bcodding@redhat.com Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com

diff --git a/fs/nfs/client.c b/fs/nfs/client.c index e13eb429b8b5..8fb4a950dd55 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -682,6 +682,44 @@ struct nfs_client *nfs_init_client(struct nfs_client *clp, } EXPORT_SYMBOL_GPL(nfs_init_client);

+static void nfs4_server_set_init_caps(struct nfs_server *server) +{ +#if IS_ENABLED(CONFIG_NFS_V4) + /* Set the basic capabilities */ + server->caps = server->nfs_client->cl_mvops->init_caps; + if (server->flags & NFS_MOUNT_NORDIRPLUS) + server->caps &= ~NFS_CAP_READDIRPLUS; + if (server->nfs_client->cl_proto == XPRT_TRANSPORT_RDMA) + server->caps &= ~NFS_CAP_READ_PLUS; + + /* + * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower + * authentication. + */ + if (nfs4_disable_idmapping && + server->client->cl_auth->au_flavor == RPC_AUTH_UNIX) + server->caps |= NFS_CAP_UIDGID_NOMAP; +#endif +} + +void nfs_server_set_init_caps(struct nfs_server *server) +{ + switch (server->nfs_client->rpc_ops->version) { + case 2: + server->caps = NFS_CAP_HARDLINKS | NFS_CAP_SYMLINKS; + break; + case 3: + server->caps = NFS_CAP_HARDLINKS | NFS_CAP_SYMLINKS; + if (!(server->flags & NFS_MOUNT_NORDIRPLUS)) + server->caps |= NFS_CAP_READDIRPLUS; + break; + default: + nfs4_server_set_init_caps(server); + break; + } +} +EXPORT_SYMBOL_GPL(nfs_server_set_init_caps); + /* * Create a version 2 or 3 client */ @@ -726,7 +764,6 @@ static int nfs_init_server(struct nfs_server *server, /* Initialise the client representation from the mount data */ server->flags = ctx->flags; server->options = ctx->options; - server->caps |= NFS_CAP_HARDLINKS | NFS_CAP_SYMLINKS;

switch (clp->rpc_ops->version) { case 2: @@ -762,6 +799,8 @@ static int nfs_init_server(struct nfs_server *server, if (error < 0) goto error;

+ nfs_server_set_init_caps(server); + /* Preserve the values of mount_server-related mount options */ if (ctx->mount_server.addrlen) { memcpy(&server->mountd_address, &ctx->mount_server.address, @@ -934,7 +973,6 @@ void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_server *sour target->acregmax = source->acregmax; target->acdirmin = source->acdirmin; target->acdirmax = source->acdirmax; - target->caps = source->caps; target->options = source->options; target->auth_info = source->auth_info; target->port = source->port; @@ -1169,6 +1207,8 @@ struct nfs_server *nfs_clone_server(struct nfs_server *source, if (error < 0) goto out_free_server;

+ nfs_server_set_init_caps(server); + /* probe the filesystem info for this server filesystem */ error = nfs_probe_server(server, fh); if (error < 0) diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index 0143e0794d32..1a18d8d9be25 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -231,7 +231,7 @@ extern struct nfs_client * nfs4_find_client_sessionid(struct net *, const struct sockaddr *, struct nfs4_sessionid *, u32); extern struct nfs_server *nfs_create_server(struct fs_context *); -extern void nfs4_server_set_init_caps(struct nfs_server *); +extern void nfs_server_set_init_caps(struct nfs_server *); extern struct nfs_server *nfs4_create_server(struct fs_context *); extern struct nfs_server *nfs4_create_referral_server(struct fs_context *); extern int nfs4_update_server(struct nfs_server *server, const char *hostname, diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c index 2ea98f1f116f..6fddf43d729c 100644 --- a/fs/nfs/nfs4client.c +++ b/fs/nfs/nfs4client.c @@ -1074,24 +1074,6 @@ static void nfs4_session_limit_xasize(struct nfs_server *server) #endif }

-void nfs4_server_set_init_caps(struct nfs_server *server) -{ - /* Set the basic capabilities */ - server->caps |= server->nfs_client->cl_mvops->init_caps; - if (server->flags & NFS_MOUNT_NORDIRPLUS) - server->caps &= ~NFS_CAP_READDIRPLUS; - if (server->nfs_client->cl_proto == XPRT_TRANSPORT_RDMA) - server->caps &= ~NFS_CAP_READ_PLUS; - - /* - * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower - * authentication. - */ - if (nfs4_disable_idmapping && - server->client->cl_auth->au_flavor == RPC_AUTH_UNIX) - server->caps |= NFS_CAP_UIDGID_NOMAP; -} - static int nfs4_server_common_setup(struct nfs_server *server, struct nfs_fh *mntfh, bool auth_probe) { @@ -1110,7 +1092,7 @@ static int nfs4_server_common_setup(struct nfs_server *server, if (error < 0) return error;

- nfs4_server_set_init_caps(server); + nfs_server_set_init_caps(server);

/* Probe the root fh to retrieve its FSID and filehandle */ error = nfs4_get_rootfh(server, mntfh, auth_probe); diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index d7dc669d84c5..c7c7ec22f21d 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -4092,7 +4092,7 @@ int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle) }; int err;

- nfs4_server_set_init_caps(server); + nfs_server_set_init_caps(server); do { err = nfs4_handle_exception(server, _nfs4_server_capabilities(server, fhandle),