[PATCH] NFS: Add support for NFSv3 ACLs

 This adds acl support fo nfs clients via the NFSACL protocol extension, by
 implementing the getxattr, listxattr, setxattr, and removexattr iops for the
 system.posix_acl_access and system.posix_acl_default attributes.  This patch
 implements a dumb version that uses no caching (and thus adds some overhead).
 (Another patch in this patchset adds caching as well.)

 Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
 Acked-by: Olaf Kirch <okir@suse.de>
 Signed-off-by: Andrew Morton <akpm@osdl.org>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 147 insertions, 0 deletions

diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c
index a3593d47e5a..a4437fb177f 100644
--- a/fs/nfs/nfs3xdr.c
+++ b/fs/nfs/nfs3xdr.c
@@ -21,6 +21,7 @@
 #include <linux/nfs.h>
 #include <linux/nfs3.h>
 #include <linux/nfs_fs.h>
+#include <linux/nfsacl.h>
 
 #define NFSDBG_FACILITY         NFSDBG_XDR
 
@@ -79,6 +80,11 @@ extern int			nfs_stat_to_errno(int);
 #define NFS3_pathconfres_sz     (1+NFS3_post_op_attr_sz+6)
 #define NFS3_commitres_sz       (1+NFS3_wcc_data_sz+2)
 
+#define ACL3_getaclargs_sz      (NFS3_fh_sz+1)
+#define ACL3_setaclargs_sz      (NFS3_fh_sz+1+2*(2+5*3))
+#define ACL3_getaclres_sz       (1+NFS3_post_op_attr_sz+1+2*(2+5*3))
+#define ACL3_setaclres_sz       (1+NFS3_post_op_attr_sz)
+
 /*
  * Map file type to S_IFMT bits
  */
@@ -627,6 +633,74 @@ nfs3_xdr_commitargs(struct rpc_rqst *req, u32 *p, struct nfs_writeargs *args)
         return 0;
 }
 
+#ifdef CONFIG_NFS_V3_ACL
+/*
+ * Encode GETACL arguments
+ */
+static int
+nfs3_xdr_getaclargs(struct rpc_rqst *req, u32 *p,
+                    struct nfs3_getaclargs *args)
+{
+        struct rpc_auth *auth = req->rq_task->tk_auth;
+        unsigned int replen;
+
+        p = xdr_encode_fhandle(p, args->fh);
+        *p++ = htonl(args->mask);
+        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
+
+        if (args->mask & (NFS_ACL | NFS_DFACL)) {
+                /* Inline the page array */
+                replen = (RPC_REPHDRSIZE + auth->au_rslack +
+                          ACL3_getaclres_sz) << 2;
+                xdr_inline_pages(&req->rq_rcv_buf, replen, args->pages, 0,
+                                 NFSACL_MAXPAGES << PAGE_SHIFT);
+        }
+        return 0;
+}
+
+/*
+ * Encode SETACL arguments
+ */
+static int
+nfs3_xdr_setaclargs(struct rpc_rqst *req, u32 *p,
+                   struct nfs3_setaclargs *args)
+{
+        struct xdr_buf *buf = &req->rq_snd_buf;
+        unsigned int base, len_in_head, len = nfsacl_size(
+                (args->mask & NFS_ACL)   ? args->acl_access  : NULL,
+                (args->mask & NFS_DFACL) ? args->acl_default : NULL);
+        int count, err;
+
+        p = xdr_encode_fhandle(p, NFS_FH(args->inode));
+        *p++ = htonl(args->mask);
+        base = (char *)p - (char *)buf->head->iov_base;
+        /* put as much of the acls into head as possible. */
+        len_in_head = min_t(unsigned int, buf->head->iov_len - base, len);
+        len -= len_in_head;
+        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p + len_in_head);
+
+        for (count = 0; (count << PAGE_SHIFT) < len; count++) {
+                args->pages[count] = alloc_page(GFP_KERNEL);
+                if (!args->pages[count]) {
+                        while (count)
+                                __free_page(args->pages[--count]);
+                        return -ENOMEM;
+                }
+        }
+        xdr_encode_pages(buf, args->pages, 0, len);
+
+        err = nfsacl_encode(buf, base, args->inode,
+                            (args->mask & NFS_ACL) ?
+                            args->acl_access : NULL, 1, 0);
+        if (err > 0)
+                err = nfsacl_encode(buf, base + err, args->inode,
+                                    (args->mask & NFS_DFACL) ?
+                                    args->acl_default : NULL, 1,
+                                    NFS_ACL_DEFAULT);
+        return (err > 0) ? 0 : err;
+}
+#endif  /* CONFIG_NFS_V3_ACL */
+
 /*
  * NFS XDR decode functions
  */
@@ -978,6 +1052,54 @@ nfs3_xdr_commitres(struct rpc_rqst *req, u32 *p, struct nfs_writeres *res)
         return 0;
 }
 
+#ifdef CONFIG_NFS_V3_ACL
+/*
+ * Decode GETACL reply
+ */
+static int
+nfs3_xdr_getaclres(struct rpc_rqst *req, u32 *p,
+                   struct nfs3_getaclres *res)
+{
+        struct xdr_buf *buf = &req->rq_rcv_buf;
+        int status = ntohl(*p++);
+        struct posix_acl **acl;
+        unsigned int *aclcnt;
+        int err, base;
+
+        if (status != 0)
+                return -nfs_stat_to_errno(status);
+        p = xdr_decode_post_op_attr(p, res->fattr);
+        res->mask = ntohl(*p++);
+        if (res->mask & ~(NFS_ACL|NFS_ACLCNT|NFS_DFACL|NFS_DFACLCNT))
+                return -EINVAL;
+        base = (char *)p - (char *)req->rq_rcv_buf.head->iov_base;
+
+        acl = (res->mask & NFS_ACL) ? &res->acl_access : NULL;
+        aclcnt = (res->mask & NFS_ACLCNT) ? &res->acl_access_count : NULL;
+        err = nfsacl_decode(buf, base, aclcnt, acl);
+
+        acl = (res->mask & NFS_DFACL) ? &res->acl_default : NULL;
+        aclcnt = (res->mask & NFS_DFACLCNT) ? &res->acl_default_count : NULL;
+        if (err > 0)
+                err = nfsacl_decode(buf, base + err, aclcnt, acl);
+        return (err > 0) ? 0 : err;
+}
+
+/*
+ * Decode setacl reply.
+ */
+static int
+nfs3_xdr_setaclres(struct rpc_rqst *req, u32 *p, struct nfs_fattr *fattr)
+{
+        int status = ntohl(*p++);
+
+        if (status)
+                return -nfs_stat_to_errno(status);
+        xdr_decode_post_op_attr(p, fattr);
+        return 0;
+}
+#endif  /* CONFIG_NFS_V3_ACL */
+
 #ifndef MAX
 # define MAX(a, b)      (((a) > (b))? (a) : (b))
 #endif
@@ -1021,3 +1143,28 @@ struct rpc_version		nfs_version3 = {
         .procs                  = nfs3_procedures
 };
 
+#ifdef CONFIG_NFS_V3_ACL
+static struct rpc_procinfo      nfs3_acl_procedures[] = {
+        [ACLPROC3_GETACL] = {
+                .p_proc = ACLPROC3_GETACL,
+                .p_encode = (kxdrproc_t) nfs3_xdr_getaclargs,
+                .p_decode = (kxdrproc_t) nfs3_xdr_getaclres,
+                .p_bufsiz = MAX(ACL3_getaclargs_sz, ACL3_getaclres_sz) << 2,
+                .p_timer = 1,
+        },
+        [ACLPROC3_SETACL] = {
+                .p_proc = ACLPROC3_SETACL,
+                .p_encode = (kxdrproc_t) nfs3_xdr_setaclargs,
+                .p_decode = (kxdrproc_t) nfs3_xdr_setaclres,
+                .p_bufsiz = MAX(ACL3_setaclargs_sz, ACL3_setaclres_sz) << 2,
+                .p_timer = 0,
+        },
+};
+
+struct rpc_version              nfsacl_version3 = {
+        .number                 = 3,
+        .nrprocs                = sizeof(nfs3_acl_procedures)/
+                                  sizeof(nfs3_acl_procedures[0]),
+        .procs                  = nfs3_acl_procedures,
+};
+#endif  /* CONFIG_NFS_V3_ACL */