From 873e385116b2cc5c7daca8f51881371fadb90970 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 9 Jun 2015 19:44:00 -0400 Subject: [PATCH] nfs: make nfs4_init_uniform_client_string use a dynamically allocated buffer Change the uniform client string generator to dynamically allocate the NFSv4 client name string buffer. With this patch, we can eliminate the buffers that are embedded within the "args" structs and simply use the name string that is hanging off the client. This uniform string case is a little simpler than the nonuniform since we don't need to deal with RCU, but we do have two different cases, depending on whether there is a uniquifier or not. Signed-off-by: Jeff Layton Signed-off-by: Trond Myklebust --- fs/nfs/nfs4proc.c | 112 +++++++++++++++++++++++++++------------- include/linux/nfs_xdr.h | 6 --- 2 files changed, 77 insertions(+), 41 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index c20322636a68..d181090124db 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -5007,28 +5007,78 @@ retry: return 0; } -static unsigned int -nfs4_init_uniform_client_string(struct nfs_client *clp, - char *buf, size_t len) +static int +nfs4_init_uniquifier_client_string(struct nfs_client *clp) { - const char *nodename = clp->cl_rpcclient->cl_nodename; - unsigned int result; + int result; + size_t len; + char *str; + + len = 10 + 10 + 1 + 10 + 1 + + strlen(nfs4_client_id_uniquifier) + 1 + + strlen(clp->cl_rpcclient->cl_nodename) + 1; + + if (len > NFS4_OPAQUE_LIMIT + 1) + return -EINVAL; + + /* + * Since this string is allocated at mount time, and held until the + * nfs_client is destroyed, we can use GFP_KERNEL here w/o worrying + * about a memory-reclaim deadlock. + */ + str = kmalloc(len, GFP_KERNEL); + if (!str) + return -ENOMEM; + + result = scnprintf(str, len, "Linux NFSv%u.%u %s/%s", + clp->rpc_ops->version, clp->cl_minorversion, + nfs4_client_id_uniquifier, + clp->cl_rpcclient->cl_nodename); + if (result >= len) { + kfree(str); + return -EINVAL; + } + clp->cl_owner_id = str; + return 0; +} + +static int +nfs4_init_uniform_client_string(struct nfs_client *clp) +{ + int result; + size_t len; + char *str; if (clp->cl_owner_id != NULL) - return strlcpy(buf, clp->cl_owner_id, len); + return 0; if (nfs4_client_id_uniquifier[0] != '\0') - result = scnprintf(buf, len, "Linux NFSv%u.%u %s/%s", - clp->rpc_ops->version, - clp->cl_minorversion, - nfs4_client_id_uniquifier, - nodename); - else - result = scnprintf(buf, len, "Linux NFSv%u.%u %s", - clp->rpc_ops->version, clp->cl_minorversion, - nodename); - clp->cl_owner_id = kstrdup(buf, GFP_KERNEL); - return result; + return nfs4_init_uniquifier_client_string(clp); + + len = 10 + 10 + 1 + 10 + 1 + + strlen(clp->cl_rpcclient->cl_nodename) + 1; + + if (len > NFS4_OPAQUE_LIMIT + 1) + return -EINVAL; + + /* + * Since this string is allocated at mount time, and held until the + * nfs_client is destroyed, we can use GFP_KERNEL here w/o worrying + * about a memory-reclaim deadlock. + */ + str = kmalloc(len, GFP_KERNEL); + if (!str) + return -ENOMEM; + + result = scnprintf(str, len, "Linux NFSv%u.%u %s", + clp->rpc_ops->version, clp->cl_minorversion, + clp->cl_rpcclient->cl_nodename); + if (result >= len) { + kfree(str); + return -EINVAL; + } + clp->cl_owner_id = str; + return 0; } /* @@ -5095,20 +5145,14 @@ int nfs4_proc_setclientid(struct nfs_client *clp, u32 program, /* nfs_client_id4 */ nfs4_init_boot_verifier(clp, &sc_verifier); - if (test_bit(NFS_CS_MIGRATION, &clp->cl_flags)) { - setclientid.sc_name_len = - nfs4_init_uniform_client_string(clp, - setclientid.sc_name, - sizeof(setclientid.sc_name)); - if (!clp->cl_owner_id) { - status = -ENOMEM; - goto out; - } - } else { + + if (test_bit(NFS_CS_MIGRATION, &clp->cl_flags)) + status = nfs4_init_uniform_client_string(clp); + else status = nfs4_init_nonuniform_client_string(clp); - if (status) - goto out; - } + + if (status) + goto out; /* cb_client4 */ setclientid.sc_netid_len = @@ -6882,12 +6926,10 @@ static int _nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred, }; nfs4_init_boot_verifier(clp, &verifier); - args.id_len = nfs4_init_uniform_client_string(clp, args.id, - sizeof(args.id)); - if (!clp->cl_owner_id) { - status = -ENOMEM; + + status = nfs4_init_uniform_client_string(clp); + if (status) goto out; - } dprintk("NFS call exchange_id auth=%s, '%s'\n", clp->cl_rpcclient->cl_auth->au_ops->au_name, diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h index 6c0b423d781b..c959e7eb5bd4 100644 --- a/include/linux/nfs_xdr.h +++ b/include/linux/nfs_xdr.h @@ -984,11 +984,8 @@ struct nfs4_readlink_res { struct nfs4_sequence_res seq_res; }; -#define NFS4_SETCLIENTID_NAMELEN (127) struct nfs4_setclientid { const nfs4_verifier * sc_verifier; - unsigned int sc_name_len; - char sc_name[NFS4_SETCLIENTID_NAMELEN + 1]; u32 sc_prog; unsigned int sc_netid_len; char sc_netid[RPCBIND_MAXNETIDLEN + 1]; @@ -1142,12 +1139,9 @@ struct nfs41_state_protection { struct nfs4_op_map allow; }; -#define NFS4_EXCHANGE_ID_LEN (127) struct nfs41_exchange_id_args { struct nfs_client *client; nfs4_verifier *verifier; - unsigned int id_len; - char id[NFS4_EXCHANGE_ID_LEN]; u32 flags; struct nfs41_state_protection state_protect; }; -- 2.20.1