[Vserver] [PATCH 06/10] vfs: pass nameidata into vfs_* to deal with per-mount permissions

From: Sam Vilain <sam.vilain_at_catalyst.net.nz>
Date: Mon 27 Feb 2006 - 05:25:32 GMT
Message-Id: <20060227052531.21148.94209.stgit@wilber.wgtn.cat-it.co.nz>

From: Herbert Pƶtzl <herbert@13thfloor.at>

Previously, vfs_* functions do not regard the vfs context that the
inodes came from for their checks.

In order to honour per-vfsmount permission options, VFS functions must
be passed the nameidata structure, similar to the existing
vfs_create().

This allows for proper checks in may_create(), may_delete() and
permission().

Acked-by: Sam Vilain <sam.vilain@catalyst.net.nz>

---
 fs/namei.c          |   59 ++++++++++++++++++++++++++++++---------------------
 fs/nfsd/vfs.c       |   16 ++++++++------
 fs/reiserfs/xattr.c |    3 ++-
 include/linux/fs.h  |   12 +++++-----
 ipc/mqueue.c        |    2 +-
 net/unix/af_unix.c  |    2 +-
 6 files changed, 54 insertions(+), 40 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index e28de84..89cccf5 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1345,7 +1345,8 @@ static inline int check_sticky(struct in
  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
  *     nfs_async_unlink().
  */
-static int may_delete(struct inode *dir,struct dentry *victim,int isdir)
+static int may_delete(struct inode *dir, struct dentry *victim,
+	int isdir, struct nameidata *nd)
 {
 	int error;
 
@@ -1354,7 +1355,7 @@ static int may_delete(struct inode *dir,
 
 	BUG_ON(victim->d_parent->d_inode != dir);
 
-	error = permission(dir,MAY_WRITE | MAY_EXEC, NULL);
+	error = permission(dir,MAY_WRITE | MAY_EXEC, nd);
 	if (error)
 		return error;
 	if (IS_APPEND(dir))
@@ -1773,9 +1774,10 @@ fail:
 }
 EXPORT_SYMBOL_GPL(lookup_create);
 
-int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
+int vfs_mknod(struct inode *dir, struct dentry *dentry,
+	int mode, dev_t dev, struct nameidata *nd)
 {
-	int error = may_create(dir, dentry, NULL);
+	int error = may_create(dir, dentry, nd);
 
 	if (error)
 		return error;
@@ -1825,11 +1827,12 @@ asmlinkage long sys_mknodat(int dfd, con
 			error = vfs_create(nd.dentry->d_inode,dentry,mode,&nd);
 			break;
 		case S_IFCHR: case S_IFBLK:
-			error = vfs_mknod(nd.dentry->d_inode,dentry,mode,
-					new_decode_dev(dev));
+			error = vfs_mknod(nd.dentry->d_inode, dentry, mode,
+					new_decode_dev(dev), &nd);
 			break;
 		case S_IFIFO: case S_IFSOCK:
-			error = vfs_mknod(nd.dentry->d_inode,dentry,mode,0);
+			error = vfs_mknod(nd.dentry->d_inode, dentry, mode,
+					0, &nd);
 			break;
 		case S_IFDIR:
 			error = -EPERM;
@@ -1852,9 +1855,10 @@ asmlinkage long sys_mknod(const char __u
 	return sys_mknodat(AT_FDCWD, filename, mode, dev);
 }
 
-int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+int vfs_mkdir(struct inode *dir, struct dentry *dentry,
+	int mode, struct nameidata *nd)
 {
-	int error = may_create(dir, dentry, NULL);
+	int error = may_create(dir, dentry, nd);
 
 	if (error)
 		return error;
@@ -1893,7 +1897,8 @@ asmlinkage long sys_mkdirat(int dfd, con
 		if (!IS_ERR(dentry)) {
 			if (!IS_POSIXACL(nd.dentry->d_inode))
 				mode &= ~current->fs->umask;
-			error = vfs_mkdir(nd.dentry->d_inode, dentry, mode);
+			error = vfs_mkdir(nd.dentry->d_inode, dentry,
+				mode, &nd);
 			dput(dentry);
 		}
 		mutex_unlock(&nd.dentry->d_inode->i_mutex);
@@ -1938,9 +1943,10 @@ void dentry_unhash(struct dentry *dentry
 	spin_unlock(&dcache_lock);
 }
 
-int vfs_rmdir(struct inode *dir, struct dentry *dentry)
+int vfs_rmdir(struct inode *dir, struct dentry *dentry,
+	struct nameidata *nd)
 {
-	int error = may_delete(dir, dentry, 1);
+	int error = may_delete(dir, dentry, 1, nd);
 
 	if (error)
 		return error;
@@ -2001,7 +2007,7 @@ static long do_rmdir(int dfd, const char
 	dentry = lookup_hash(&nd);
 	error = PTR_ERR(dentry);
 	if (!IS_ERR(dentry)) {
-		error = vfs_rmdir(nd.dentry->d_inode, dentry);
+		error = vfs_rmdir(nd.dentry->d_inode, dentry, &nd);
 		dput(dentry);
 	}
 	mutex_unlock(&nd.dentry->d_inode->i_mutex);
@@ -2017,9 +2023,10 @@ asmlinkage long sys_rmdir(const char __u
 	return do_rmdir(AT_FDCWD, pathname);
 }
 
-int vfs_unlink(struct inode *dir, struct dentry *dentry)
+int vfs_unlink(struct inode *dir, struct dentry *dentry,
+	struct nameidata *nd)
 {
-	int error = may_delete(dir, dentry, 0);
+	int error = may_delete(dir, dentry, 0, nd);
 
 	if (error)
 		return error;
@@ -2081,7 +2088,7 @@ static long do_unlinkat(int dfd, const c
 		inode = dentry->d_inode;
 		if (inode)
 			atomic_inc(&inode->i_count);
-		error = vfs_unlink(nd.dentry->d_inode, dentry);
+		error = vfs_unlink(nd.dentry->d_inode, dentry, &nd);
 	exit2:
 		dput(dentry);
 	}
@@ -2116,9 +2123,10 @@ asmlinkage long sys_unlink(const char __
 	return do_unlinkat(AT_FDCWD, pathname);
 }
 
-int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname, int mode)
+int vfs_symlink(struct inode *dir, struct dentry *dentry,
+	const char *oldname, int mode, struct nameidata *nd)
 {
-	int error = may_create(dir, dentry, NULL);
+	int error = may_create(dir, dentry, nd);
 
 	if (error)
 		return error;
@@ -2159,7 +2167,8 @@ asmlinkage long sys_symlinkat(const char
 		dentry = lookup_create(&nd, 0);
 		error = PTR_ERR(dentry);
 		if (!IS_ERR(dentry)) {
-			error = vfs_symlink(nd.dentry->d_inode, dentry, from, S_IALLUGO);
+			error = vfs_symlink(nd.dentry->d_inode, dentry,
+				from, S_IALLUGO, &nd);
 			dput(dentry);
 		}
 		mutex_unlock(&nd.dentry->d_inode->i_mutex);
@@ -2176,7 +2185,8 @@ asmlinkage long sys_symlink(const char _
 	return sys_symlinkat(oldname, AT_FDCWD, newname);
 }
 
-int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
+int vfs_link(struct dentry *old_dentry, struct inode *dir,
+	struct dentry *new_dentry, struct nameidata *nd)
 {
 	struct inode *inode = old_dentry->d_inode;
 	int error;
@@ -2184,7 +2194,7 @@ int vfs_link(struct dentry *old_dentry, 
 	if (!inode)
 		return -ENOENT;
 
-	error = may_create(dir, new_dentry, NULL);
+	error = may_create(dir, new_dentry, nd);
 	if (error)
 		return error;
 
@@ -2247,7 +2257,8 @@ asmlinkage long sys_linkat(int olddfd, c
 	new_dentry = lookup_create(&nd, 0);
 	error = PTR_ERR(new_dentry);
 	if (!IS_ERR(new_dentry)) {
-		error = vfs_link(old_nd.dentry, nd.dentry->d_inode, new_dentry);
+		error = vfs_link(old_nd.dentry, nd.dentry->d_inode,
+			new_dentry, &nd);
 		dput(new_dentry);
 	}
 	mutex_unlock(&nd.dentry->d_inode->i_mutex);
@@ -2379,14 +2390,14 @@ int vfs_rename(struct inode *old_dir, st
 	if (old_dentry->d_inode == new_dentry->d_inode)
  		return 0;
  
-	error = may_delete(old_dir, old_dentry, is_dir);
+	error = may_delete(old_dir, old_dentry, is_dir, NULL);
 	if (error)
 		return error;
 
 	if (!new_dentry->d_inode)
 		error = may_create(new_dir, new_dentry, NULL);
 	else
-		error = may_delete(new_dir, new_dentry, is_dir);
+		error = may_delete(new_dir, new_dentry, is_dir, NULL);
 	if (error)
 		return error;
 
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 5320e5a..6fe2491 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1160,13 +1160,13 @@ nfsd_create(struct svc_rqst *rqstp, stru
 		err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
 		break;
 	case S_IFDIR:
-		err = vfs_mkdir(dirp, dchild, iap->ia_mode);
+		err = vfs_mkdir(dirp, dchild, iap->ia_mode, NULL);
 		break;
 	case S_IFCHR:
 	case S_IFBLK:
 	case S_IFIFO:
 	case S_IFSOCK:
-		err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
+		err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev, NULL);
 		break;
 	default:
 	        printk("nfsd: bad file type %o in nfsd_create\n", type);
@@ -1446,11 +1446,13 @@ nfsd_symlink(struct svc_rqst *rqstp, str
 		else {
 			strncpy(path_alloced, path, plen);
 			path_alloced[plen] = 0;
-			err = vfs_symlink(dentry->d_inode, dnew, path_alloced, mode);
+			err = vfs_symlink(dentry->d_inode, dnew,
+				path_alloced, mode, NULL);
 			kfree(path_alloced);
 		}
 	} else
-		err = vfs_symlink(dentry->d_inode, dnew, path, mode);
+		err = vfs_symlink(dentry->d_inode, dnew,
+			path, mode, NULL);
 
 	if (!err)
 		if (EX_ISSYNC(fhp->fh_export))
@@ -1508,7 +1510,7 @@ nfsd_link(struct svc_rqst *rqstp, struct
 	dold = tfhp->fh_dentry;
 	dest = dold->d_inode;
 
-	err = vfs_link(dold, dirp, dnew);
+	err = vfs_link(dold, dirp, dnew, NULL);
 	if (!err) {
 		if (EX_ISSYNC(ffhp->fh_export)) {
 			err = nfserrno(nfsd_sync_dir(ddir));
@@ -1670,9 +1672,9 @@ nfsd_unlink(struct svc_rqst *rqstp, stru
 			err = -EPERM;
 		} else
 #endif
-		err = vfs_unlink(dirp, rdentry);
+		err = vfs_unlink(dirp, rdentry, NULL);
 	} else { /* It's RMDIR */
-		err = vfs_rmdir(dirp, rdentry);
+		err = vfs_rmdir(dirp, rdentry, NULL);
 	}
 
 	dput(rdentry);
diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index ffb79c4..b99819a 100644
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -35,6 +35,7 @@
 #include <linux/namei.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
+#include <linux/mount.h>
 #include <linux/file.h>
 #include <linux/pagemap.h>
 #include <linux/xattr.h>
@@ -824,7 +825,7 @@ int reiserfs_delete_xattrs(struct inode 
 	if (dir->d_inode->i_nlink <= 2) {
 		root = get_xa_root(inode->i_sb);
 		reiserfs_write_lock_xattrs(inode->i_sb);
-		err = vfs_rmdir(root->d_inode, dir);
+		err = vfs_rmdir(root->d_inode, dir, NULL);
 		reiserfs_write_unlock_xattrs(inode->i_sb);
 		dput(root);
 	} else {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2a0866a..3000655 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -903,12 +903,12 @@ static inline void unlock_super(struct s
  */
 extern int vfs_permission(struct nameidata *, int);
 extern int vfs_create(struct inode *, struct dentry *, int, struct nameidata *);
-extern int vfs_mkdir(struct inode *, struct dentry *, int);
-extern int vfs_mknod(struct inode *, struct dentry *, int, dev_t);
-extern int vfs_symlink(struct inode *, struct dentry *, const char *, int);
-extern int vfs_link(struct dentry *, struct inode *, struct dentry *);
-extern int vfs_rmdir(struct inode *, struct dentry *);
-extern int vfs_unlink(struct inode *, struct dentry *);
+extern int vfs_mkdir(struct inode *, struct dentry *, int, struct nameidata *);
+extern int vfs_mknod(struct inode *, struct dentry *, int, dev_t, struct nameidata *);
+extern int vfs_symlink(struct inode *, struct dentry *, const char *, int, struct nameidata *);
+extern int vfs_link(struct dentry *, struct inode *, struct dentry *, struct nameidata *);
+extern int vfs_rmdir(struct inode *, struct dentry *, struct nameidata *);
+extern int vfs_unlink(struct inode *, struct dentry *, struct nameidata *);
 extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
 
 /*
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index fd2e26b..57391b7 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -738,7 +738,7 @@ asmlinkage long sys_mq_unlink(const char
 	if (inode)
 		atomic_inc(&inode->i_count);
 
-	err = vfs_unlink(dentry->d_parent->d_inode, dentry);
+	err = vfs_unlink(dentry->d_parent->d_inode, dentry, NULL);
 out_err:
 	dput(dentry);
 
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 1b5989b..10b3375 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -781,7 +781,7 @@ static int unix_bind(struct socket *sock
 		 */
 		mode = S_IFSOCK |
 		       (SOCK_INODE(sock)->i_mode & ~current->fs->umask);
-		err = vfs_mknod(nd.dentry->d_inode, dentry, mode, 0);
+		err = vfs_mknod(nd.dentry->d_inode, dentry, mode, 0, NULL);
 		if (err)
 			goto out_mknod_dput;
 		mutex_unlock(&nd.dentry->d_inode->i_mutex);
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