From 05ad917561fca39a03338cb21fe9622f998b0f9c Mon Sep 17 00:00:00 2001 From: Olga Kornievskaia Date: Fri, 6 Nov 2020 16:03:38 -0500 Subject: [PATCH] NFSv4.2: condition READDIR's mask for security label based on LSM state Currently, the client will always ask for security_labels if the server returns that it supports that feature regardless of any LSM modules (such as Selinux) enforcing security policy. This adds performance penalty to the READDIR operation. Client adjusts superblock's support of the security_label based on the server's support but also current client's configuration of the LSM modules. Thus, prior to using the default bitmask in READDIR, this patch checks the server's capabilities and then instructs READDIR to remove FATTR4_WORD2_SECURITY_LABEL from the bitmask. v5: fixing silly mistakes of the rushed v4 v4: simplifying logic v3: changing label's initialization per Ondrej's comment v2: dropping selinux hook and using the sb cap. Suggested-by: Ondrej Mosnacek Suggested-by: Scott Mayhew Signed-off-by: Olga Kornievskaia Fixes: 2b0143b5c986 ("VFS: normal filesystems (and lustre): d_inode() annotations") Signed-off-by: Trond Myklebust --- fs/nfs/nfs4proc.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index a5b9356bee6a..66f1f4a5c74c 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -4965,12 +4965,12 @@ static int _nfs4_proc_readdir(struct dentry *dentry, const struct cred *cred, u64 cookie, struct page **pages, unsigned int count, bool plus) { struct inode *dir = d_inode(dentry); + struct nfs_server *server = NFS_SERVER(dir); struct nfs4_readdir_arg args = { .fh = NFS_FH(dir), .pages = pages, .pgbase = 0, .count = count, - .bitmask = NFS_SERVER(d_inode(dentry))->attr_bitmask, .plus = plus, }; struct nfs4_readdir_res res; @@ -4985,9 +4985,15 @@ static int _nfs4_proc_readdir(struct dentry *dentry, const struct cred *cred, dprintk("%s: dentry = %pd2, cookie = %Lu\n", __func__, dentry, (unsigned long long)cookie); + if (!(server->caps & NFS_CAP_SECURITY_LABEL)) + args.bitmask = server->attr_bitmask_nl; + else + args.bitmask = server->attr_bitmask; + nfs4_setup_readdir(cookie, NFS_I(dir)->cookieverf, dentry, &args); res.pgbase = args.pgbase; - status = nfs4_call_sync(NFS_SERVER(dir)->client, NFS_SERVER(dir), &msg, &args.seq_args, &res.seq_res, 0); + status = nfs4_call_sync(server->client, server, &msg, &args.seq_args, + &res.seq_res, 0); if (status >= 0) { memcpy(NFS_I(dir)->cookieverf, res.verifier.data, NFS4_VERIFIER_SIZE); status += args.pgbase; -- 2.11.0