nfs: use generic posix ACL infrastructure for v3 Posix ACLs

This causes a small behaviour change in that we don't bother to set
ACLs on file creation if the mode bit can express the access permissions
fully, and thus behaving identical to local filesystems.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 55 insertions, 236 deletions

diff --git a/fs/nfs/nfs3acl.c b/fs/nfs/nfs3acl.c
index e859675..9a5ca03 100644
--- a/fs/nfs/nfs3acl.c
+++ b/fs/nfs/nfs3acl.c
@@ -10,179 +10,7 @@
 
 #define NFSDBG_FACILITY	NFSDBG_PROC
 
-ssize_t nfs3_listxattr(struct dentry *dentry, char *buffer, size_t size)
-{
-	struct inode *inode = dentry->d_inode;
-	struct posix_acl *acl;
-	int pos=0, len=0;
-
-#	define output(s) do {						\
-			if (pos + sizeof(s) <= size) {			\
-				memcpy(buffer + pos, s, sizeof(s));	\
-				pos += sizeof(s);			\
-			}						\
-			len += sizeof(s);				\
-		} while(0)
-
-	acl = nfs3_proc_getacl(inode, ACL_TYPE_ACCESS);
-	if (IS_ERR(acl))
-		return PTR_ERR(acl);
-	if (acl) {
-		output("system.posix_acl_access");
-		posix_acl_release(acl);
-	}
-
-	if (S_ISDIR(inode->i_mode)) {
-		acl = nfs3_proc_getacl(inode, ACL_TYPE_DEFAULT);
-		if (IS_ERR(acl))
-			return PTR_ERR(acl);
-		if (acl) {
-			output("system.posix_acl_default");
-			posix_acl_release(acl);
-		}
-	}
-
-#	undef output
-
-	if (!buffer || len <= size)
-		return len;
-	return -ERANGE;
-}
-
-ssize_t nfs3_getxattr(struct dentry *dentry, const char *name,
-		void *buffer, size_t size)
-{
-	struct inode *inode = dentry->d_inode;
-	struct posix_acl *acl;
-	int type, error = 0;
-
-	if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
-		type = ACL_TYPE_ACCESS;
-	else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
-		type = ACL_TYPE_DEFAULT;
-	else
-		return -EOPNOTSUPP;
-
-	acl = nfs3_proc_getacl(inode, type);
-	if (IS_ERR(acl))
-		return PTR_ERR(acl);
-	else if (acl) {
-		if (type == ACL_TYPE_ACCESS && acl->a_count == 0)
-			error = -ENODATA;
-		else
-			error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
-		posix_acl_release(acl);
-	} else
-		error = -ENODATA;
-
-	return error;
-}
-
-int nfs3_setxattr(struct dentry *dentry, const char *name,
-	     const void *value, size_t size, int flags)
-{
-	struct inode *inode = dentry->d_inode;
-	struct posix_acl *acl;
-	int type, error;
-
-	if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
-		type = ACL_TYPE_ACCESS;
-	else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
-		type = ACL_TYPE_DEFAULT;
-	else
-		return -EOPNOTSUPP;
-
-	acl = posix_acl_from_xattr(&init_user_ns, value, size);
-	if (IS_ERR(acl))
-		return PTR_ERR(acl);
-	error = nfs3_proc_setacl(inode, type, acl);
-	posix_acl_release(acl);
-
-	return error;
-}
-
-int nfs3_removexattr(struct dentry *dentry, const char *name)
-{
-	struct inode *inode = dentry->d_inode;
-	int type;
-
-	if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
-		type = ACL_TYPE_ACCESS;
-	else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
-		type = ACL_TYPE_DEFAULT;
-	else
-		return -EOPNOTSUPP;
-
-	return nfs3_proc_setacl(inode, type, NULL);
-}
-
-static void __nfs3_forget_cached_acls(struct nfs_inode *nfsi)
-{
-	if (!IS_ERR(nfsi->acl_access)) {
-		posix_acl_release(nfsi->acl_access);
-		nfsi->acl_access = ERR_PTR(-EAGAIN);
-	}
-	if (!IS_ERR(nfsi->acl_default)) {
-		posix_acl_release(nfsi->acl_default);
-		nfsi->acl_default = ERR_PTR(-EAGAIN);
-	}
-}
-
-void nfs3_forget_cached_acls(struct inode *inode)
-{
-	dprintk("NFS: nfs3_forget_cached_acls(%s/%ld)\n", inode->i_sb->s_id,
-		inode->i_ino);
-	spin_lock(&inode->i_lock);
-	__nfs3_forget_cached_acls(NFS_I(inode));
-	spin_unlock(&inode->i_lock);
-}
-
-static struct posix_acl *nfs3_get_cached_acl(struct inode *inode, int type)
-{
-	struct nfs_inode *nfsi = NFS_I(inode);
-	struct posix_acl *acl = ERR_PTR(-EINVAL);
-
-	spin_lock(&inode->i_lock);
-	switch(type) {
-		case ACL_TYPE_ACCESS:
-			acl = nfsi->acl_access;
-			break;
-
-		case ACL_TYPE_DEFAULT:
-			acl = nfsi->acl_default;
-			break;
-
-		default:
-			goto out;
-	}
-	if (IS_ERR(acl))
-		acl = ERR_PTR(-EAGAIN);
-	else
-		acl = posix_acl_dup(acl);
-out:
-	spin_unlock(&inode->i_lock);
-	dprintk("NFS: nfs3_get_cached_acl(%s/%ld, %d) = %p\n", inode->i_sb->s_id,
-		inode->i_ino, type, acl);
-	return acl;
-}
-
-static void nfs3_cache_acls(struct inode *inode, struct posix_acl *acl,
-		    struct posix_acl *dfacl)
-{
-	struct nfs_inode *nfsi = NFS_I(inode);
-
-	dprintk("nfs3_cache_acls(%s/%ld, %p, %p)\n", inode->i_sb->s_id,
-		inode->i_ino, acl, dfacl);
-	spin_lock(&inode->i_lock);
-	__nfs3_forget_cached_acls(NFS_I(inode));
-	if (!IS_ERR(acl))
-		nfsi->acl_access = posix_acl_dup(acl);
-	if (!IS_ERR(dfacl))
-		nfsi->acl_default = posix_acl_dup(dfacl);
-	spin_unlock(&inode->i_lock);
-}
-
-struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type)
+struct posix_acl *nfs3_get_acl(struct inode *inode, int type)
 {
 	struct nfs_server *server = NFS_SERVER(inode);
 	struct page *pages[NFSACL_MAXPAGES] = { };
@@ -198,7 +26,6 @@ struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type)
 		.rpc_argp	= &args,
 		.rpc_resp	= &res,
 	};
-	struct posix_acl *acl;
 	int status, count;
 
 	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
@@ -207,10 +34,6 @@ struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type)
 	status = nfs_revalidate_inode(server, inode);
 	if (status < 0)
 		return ERR_PTR(status);
-	acl = nfs3_get_cached_acl(inode, type);
-	if (acl != ERR_PTR(-EAGAIN))
-		return acl;
-	acl = NULL;
 
 	/*
 	 * Only get the access acl when explicitly requested: We don't
@@ -257,40 +80,41 @@ struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type)
 	}
 
 	if (res.acl_access != NULL) {
-		if (posix_acl_equiv_mode(res.acl_access, NULL) == 0) {
+		if (posix_acl_equiv_mode(res.acl_access, NULL) ||
+		    res.acl_access->a_count == 0) {
 			posix_acl_release(res.acl_access);
 			res.acl_access = NULL;
 		}
 	}
-	nfs3_cache_acls(inode,
-		(res.mask & NFS_ACL)   ? res.acl_access  : ERR_PTR(-EINVAL),
-		(res.mask & NFS_DFACL) ? res.acl_default : ERR_PTR(-EINVAL));
 
-	switch(type) {
-		case ACL_TYPE_ACCESS:
-			acl = res.acl_access;
-			res.acl_access = NULL;
-			break;
+	if (res.mask & NFS_ACL)
+		set_cached_acl(inode, ACL_TYPE_ACCESS, res.acl_access);
+	else
+		forget_cached_acl(inode, ACL_TYPE_ACCESS);
 
-		case ACL_TYPE_DEFAULT:
-			acl = res.acl_default;
-			res.acl_default = NULL;
+	if (res.mask & NFS_DFACL)
+		set_cached_acl(inode, ACL_TYPE_DEFAULT, res.acl_default);
+	else
+		forget_cached_acl(inode, ACL_TYPE_DEFAULT);
+
+	nfs_free_fattr(res.fattr);
+	if (type == ACL_TYPE_ACCESS) {
+		posix_acl_release(res.acl_default);
+		return res.acl_access;
+	} else {
+		posix_acl_release(res.acl_access);
+		return res.acl_default;
 	}
 
 getout:
 	posix_acl_release(res.acl_access);
 	posix_acl_release(res.acl_default);
 	nfs_free_fattr(res.fattr);
-
-	if (status != 0) {
-		posix_acl_release(acl);
-		acl = ERR_PTR(status);
-	}
-	return acl;
+	return ERR_PTR(status);
 }
 
-static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
-		  struct posix_acl *dfacl)
+int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
+		struct posix_acl *dfacl)
 {
 	struct nfs_server *server = NFS_SERVER(inode);
 	struct nfs_fattr *fattr;
@@ -353,7 +177,8 @@ static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
 	switch (status) {
 		case 0:
 			status = nfs_refresh_inode(inode, fattr);
-			nfs3_cache_acls(inode, acl, dfacl);
+			set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
+			set_cached_acl(inode, ACL_TYPE_DEFAULT, dfacl);
 			break;
 		case -EPFNOSUPPORT:
 		case -EPROTONOSUPPORT:
@@ -373,33 +198,27 @@ out:
 	return status;
 }
 
-int nfs3_proc_setacl(struct inode *inode, int type, struct posix_acl *acl)
+int nfs3_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 {
 	struct posix_acl *alloc = NULL, *dfacl = NULL;
 	int status;
 
 	if (S_ISDIR(inode->i_mode)) {
 		switch(type) {
-			case ACL_TYPE_ACCESS:
-				alloc = dfacl = nfs3_proc_getacl(inode,
-						ACL_TYPE_DEFAULT);
-				if (IS_ERR(alloc))
-					goto fail;
-				break;
-
-			case ACL_TYPE_DEFAULT:
-				dfacl = acl;
-				alloc = acl = nfs3_proc_getacl(inode,
-						ACL_TYPE_ACCESS);
-				if (IS_ERR(alloc))
-					goto fail;
-				break;
-
-			default:
-				return -EINVAL;
+		case ACL_TYPE_ACCESS:
+			alloc = dfacl = get_acl(inode, ACL_TYPE_DEFAULT);
+			if (IS_ERR(alloc))
+				goto fail;
+			break;
+
+		case ACL_TYPE_DEFAULT:
+			dfacl = acl;
+			alloc = acl = get_acl(inode, ACL_TYPE_ACCESS);
+			if (IS_ERR(alloc))
+				goto fail;
+			break;
 		}
-	} else if (type != ACL_TYPE_ACCESS)
-			return -EINVAL;
+	}
 
 	if (acl == NULL) {
 		alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
@@ -417,24 +236,24 @@ fail:
 int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
 		umode_t mode)
 {
-	struct posix_acl *dfacl, *acl;
-	int error = 0;
+	struct posix_acl *default_acl, *acl;
+	int error;
 
-	dfacl = nfs3_proc_getacl(dir, ACL_TYPE_DEFAULT);
-	if (IS_ERR(dfacl)) {
-		error = PTR_ERR(dfacl);
+	error = posix_acl_create(dir, &mode, &default_acl, &acl);
+	if (error)
 		return (error == -EOPNOTSUPP) ? 0 : error;
-	}
-	if (!dfacl)
-		return 0;
-	acl = posix_acl_dup(dfacl);
-	error = __posix_acl_create(&acl, GFP_KERNEL, &mode);
-	if (error < 0)
-		goto out_release_dfacl;
-	error = nfs3_proc_setacls(inode, acl, S_ISDIR(inode->i_mode) ?
-						      dfacl : NULL);
-	posix_acl_release(acl);
-out_release_dfacl:
-	posix_acl_release(dfacl);
+
+	error = nfs3_proc_setacls(inode, acl, default_acl);
+
+	if (acl)
+		posix_acl_release(acl);
+	if (default_acl)
+		posix_acl_release(default_acl);
 	return error;
 }
+
+const struct xattr_handler *nfs3_xattr_handlers[] = {
+	&posix_acl_access_xattr_handler,
+	&posix_acl_default_xattr_handler,
+	NULL,
+};