From aa1870af92d8f6d6db0883696516a83ff2b695a6 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Wed, 22 Jun 2005 17:16:22 +0000 Subject: [PATCH] NFSv4: ACL support for the NFSv4 client: read Client-side support for NFSv4 ACLs. Exports the raw xdr code via the system.nfs4_acl extended attribute. It is up to userspace to decode the acl (and to provide correctly xdr'd acls on setxattr), and to convert to/from POSIX ACLs if desired. This patch provides only the read support. Signed-off-by: J. Bruce Fields Signed-off-by: Trond Myklebust --- fs/nfs/nfs4proc.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 65 insertions(+), 4 deletions(-) (limited to 'fs/nfs') diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 1b14d17ae9a4..c91c09938a55 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -2162,6 +2162,60 @@ nfs4_proc_file_release(struct inode *inode, struct file *filp) return 0; } +static inline int nfs4_server_supports_acls(struct nfs_server *server) +{ + return (server->caps & NFS_CAP_ACLS) + && (server->acl_bitmask & ACL4_SUPPORT_ALLOW_ACL) + && (server->acl_bitmask & ACL4_SUPPORT_DENY_ACL); +} + +/* Assuming that XATTR_SIZE_MAX is a multiple of PAGE_CACHE_SIZE, and that + * it's OK to put sizeof(void) * (XATTR_SIZE_MAX/PAGE_CACHE_SIZE) bytes on + * the stack. + */ +#define NFS4ACL_MAXPAGES (XATTR_SIZE_MAX >> PAGE_CACHE_SHIFT) + +static void buf_to_pages(const void *buf, size_t buflen, + struct page **pages, unsigned int *pgbase) +{ + const void *p = buf; + + *pgbase = offset_in_page(buf); + p -= *pgbase; + while (p < buf + buflen) { + *(pages++) = virt_to_page(p); + p += PAGE_CACHE_SIZE; + } +} + +static ssize_t nfs4_proc_get_acl(struct inode *inode, void *buf, size_t buflen) +{ + struct nfs_server *server = NFS_SERVER(inode); + struct page *pages[NFS4ACL_MAXPAGES]; + struct nfs_getaclargs args = { + .fh = NFS_FH(inode), + .acl_pages = pages, + .acl_len = buflen, + }; + size_t resp_len = buflen; + struct rpc_message msg = { + .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_GETACL], + .rpc_argp = &args, + .rpc_resp = &resp_len, + }; + int ret; + + if (!nfs4_server_supports_acls(server)) + return -EOPNOTSUPP; + buf_to_pages(buf, buflen, args.acl_pages, &args.acl_pgbase); + ret = rpc_call_sync(NFS_CLIENT(inode), &msg, 0); + if (buflen && resp_len > buflen) + return -ERANGE; + if (ret == 0) + ret = resp_len; + return ret; +} + static int nfs4_async_handle_error(struct rpc_task *task, struct nfs_server *server) { @@ -2733,6 +2787,8 @@ nfs4_proc_lock(struct file *filp, int cmd, struct file_lock *request) } +#define XATTR_NAME_NFSV4_ACL "system.nfs4_acl" + int nfs4_setxattr(struct dentry *dentry, const char *key, const void *buf, size_t buflen, int flags) { @@ -2746,18 +2802,23 @@ int nfs4_setxattr(struct dentry *dentry, const char *key, const void *buf, ssize_t nfs4_getxattr(struct dentry *dentry, const char *key, void *buf, size_t buflen) { - return -EOPNOTSUPP; + struct inode *inode = dentry->d_inode; + + if (strcmp(key, XATTR_NAME_NFSV4_ACL) != 0) + return -EOPNOTSUPP; + + return nfs4_proc_get_acl(inode, buf, buflen); } ssize_t nfs4_listxattr(struct dentry *dentry, char *buf, size_t buflen) { - ssize_t len = 0; + size_t len = strlen(XATTR_NAME_NFSV4_ACL) + 1; if (buf && buflen < len) return -ERANGE; if (buf) - memcpy(buf, "", 0); - return 0; + memcpy(buf, XATTR_NAME_NFSV4_ACL, len); + return len; } struct nfs4_state_recovery_ops nfs4_reboot_recovery_ops = { -- cgit v1.2.3-70-g09d2