jfs: use generic posix ACL infrastructure

Copy the scheme I introduced to btrfs many years ago to only use the
xattr handler for ACLs, but pass plain attrs straight through.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/jfs/acl.c

@@ -72,7 +72,7 @@ struct posix_acl *jfs_get_acl(struct inode *inode, int type)
 	return acl;
 }
 
-static int jfs_set_acl(tid_t tid, struct inode *inode, int type,
+static int __jfs_set_acl(tid_t tid, struct inode *inode, int type,
 		       struct posix_acl *acl)
 {
 	char *ea_name;
@@ -80,21 +80,22 @@ static int jfs_set_acl(tid_t tid, struct inode *inode, int type,
 	int size = 0;
 	char *value = NULL;
 
-	if (S_ISLNK(inode->i_mode))
-		return -EOPNOTSUPP;
-
-	switch(type) {
+	switch (type) {
 	case ACL_TYPE_ACCESS:
 		ea_name = POSIX_ACL_XATTR_ACCESS;
+		rc = posix_acl_equiv_mode(acl, &inode->i_mode);
+		if (rc < 0)
+			return rc;
+		if (rc == 0)
+			acl = NULL;
 		break;
 	case ACL_TYPE_DEFAULT:
 		ea_name = POSIX_ACL_XATTR_DEFAULT;
-			if (!S_ISDIR(inode->i_mode))
-				return acl ? -EACCES : 0;
 		break;
 	default:
 		return -EINVAL;
 	}
+
 	if (acl) {
 		size = posix_acl_xattr_size(acl->a_count);
 		value = kmalloc(size, GFP_KERNEL);
@@ -114,65 +115,43 @@ static int jfs_set_acl(tid_t tid, struct inode *inode, int type,
 	return rc;
 }
 
-int jfs_init_acl(tid_t tid, struct inode *inode, struct inode *dir)
-{
-	struct posix_acl *acl = NULL;
-	int rc = 0;
-
-	if (S_ISLNK(inode->i_mode))
-		return 0;
-
-	acl = jfs_get_acl(dir, ACL_TYPE_DEFAULT);
-	if (IS_ERR(acl))
-		return PTR_ERR(acl);
-
-	if (acl) {
-		if (S_ISDIR(inode->i_mode)) {
-			rc = jfs_set_acl(tid, inode, ACL_TYPE_DEFAULT, acl);
-			if (rc)
-				goto cleanup;
-		}
-		rc = __posix_acl_create(&acl, GFP_KERNEL, &inode->i_mode);
-		if (rc < 0)
-			goto cleanup; /* posix_acl_release(NULL) is no-op */
-		if (rc > 0)
-			rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, acl);
-cleanup:
-		posix_acl_release(acl);
-	} else
-		inode->i_mode &= ~current_umask();
-
-	JFS_IP(inode)->mode2 = (JFS_IP(inode)->mode2 & 0xffff0000) |
-			       inode->i_mode;
-
-	return rc;
-}
-
-int jfs_acl_chmod(struct inode *inode)
+int jfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 {
-	struct posix_acl *acl;
 	int rc;
 	tid_t tid;
 
-	if (S_ISLNK(inode->i_mode))
-		return -EOPNOTSUPP;
-
-	acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
-	if (IS_ERR(acl) || !acl)
-		return PTR_ERR(acl);
-
-	rc = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
-	if (rc)
-		return rc;
-
 	tid = txBegin(inode->i_sb, 0);
 	mutex_lock(&JFS_IP(inode)->commit_mutex);
-	rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, acl);
+	rc = __jfs_set_acl(tid, inode, type, acl);
 	if (!rc)
 		rc = txCommit(tid, 1, &inode, 0);
 	txEnd(tid);
 	mutex_unlock(&JFS_IP(inode)->commit_mutex);
+	return rc;
+}
+
+int jfs_init_acl(tid_t tid, struct inode *inode, struct inode *dir)
+{
+	struct posix_acl *default_acl, *acl;
+	int rc = 0;
 
+	rc = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
+	if (rc)
+		return rc;
+
+	if (default_acl) {
+		rc = __jfs_set_acl(tid, inode, ACL_TYPE_DEFAULT, default_acl);
+		posix_acl_release(default_acl);
+	}
+
+	if (acl) {
+		if (!rc)
+			rc = __jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, acl);
 		posix_acl_release(acl);
+	}
+
+	JFS_IP(inode)->mode2 = (JFS_IP(inode)->mode2 & 0xffff0000) |
+			       inode->i_mode;
+
 	return rc;
 }

fs/jfs/file.c

@@ -19,6 +19,7 @@
 
 #include <linux/mm.h>
 #include <linux/fs.h>
+#include <linux/posix_acl.h>
 #include <linux/quotaops.h>
 #include "jfs_incore.h"
 #include "jfs_inode.h"
@@ -131,7 +132,7 @@ int jfs_setattr(struct dentry *dentry, struct iattr *iattr)
 	mark_inode_dirty(inode);
 
 	if (iattr->ia_valid & ATTR_MODE)
-		rc = jfs_acl_chmod(inode);
+		rc = posix_acl_chmod(inode, inode->i_mode);
 	return rc;
 }
 
@@ -143,6 +144,7 @@ const struct inode_operations jfs_file_inode_operations = {
 	.setattr	= jfs_setattr,
 #ifdef CONFIG_JFS_POSIX_ACL
 	.get_acl	= jfs_get_acl,
+	.set_acl	= jfs_set_acl,
 #endif
 };
 

fs/jfs/jfs_acl.h

@@ -21,8 +21,8 @@
 #ifdef CONFIG_JFS_POSIX_ACL
 
 struct posix_acl *jfs_get_acl(struct inode *inode, int type);
+int jfs_set_acl(struct inode *inode, struct posix_acl *acl, int type);
 int jfs_init_acl(tid_t, struct inode *, struct inode *);
-int jfs_acl_chmod(struct inode *inode);
 
 #else
 
@@ -32,10 +32,5 @@ static inline int jfs_init_acl(tid_t tid, struct inode *inode,
 	return 0;
 }
 
-static inline int jfs_acl_chmod(struct inode *inode)
-{
-	return 0;
-}
-
 #endif
 #endif		/* _H_JFS_ACL */

fs/jfs/jfs_xattr.h

@@ -61,6 +61,8 @@ extern ssize_t jfs_getxattr(struct dentry *, const char *, void *, size_t);
 extern ssize_t jfs_listxattr(struct dentry *, char *, size_t);
 extern int jfs_removexattr(struct dentry *, const char *);
 
+extern const struct xattr_handler *jfs_xattr_handlers[];
+
 #ifdef CONFIG_JFS_SECURITY
 extern int jfs_init_security(tid_t, struct inode *, struct inode *,
 			     const struct qstr *);

fs/jfs/namei.c

@@ -1524,6 +1524,7 @@ const struct inode_operations jfs_dir_inode_operations = {
 	.setattr	= jfs_setattr,
 #ifdef CONFIG_JFS_POSIX_ACL
 	.get_acl	= jfs_get_acl,
+	.set_acl	= jfs_set_acl,
 #endif
 };
 

fs/jfs/super.c

@@ -44,6 +44,7 @@
 #include "jfs_imap.h"
 #include "jfs_acl.h"
 #include "jfs_debug.h"
+#include "jfs_xattr.h"
 
 MODULE_DESCRIPTION("The Journaled Filesystem (JFS)");
 MODULE_AUTHOR("Steve Best/Dave Kleikamp/Barry Arndt, IBM");
@@ -522,6 +523,7 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 	 */
 	sb->s_op = &jfs_super_operations;
 	sb->s_export_op = &jfs_export_operations;
+	sb->s_xattr = jfs_xattr_handlers;
 #ifdef CONFIG_QUOTA
 	sb->dq_op = &dquot_operations;
 	sb->s_qcop = &dquot_quotactl_ops;

fs/jfs/xattr.c

@@ -665,82 +665,13 @@ static int ea_put(tid_t tid, struct inode *inode, struct ea_buffer *ea_buf,
 	return 0;
 }
 
-/*
- * can_set_system_xattr
- *
- * This code is specific to the system.* namespace.  It contains policy
- * which doesn't belong in the main xattr codepath.
- */
-static int can_set_system_xattr(struct inode *inode, const char *name,
-				const void *value, size_t value_len)
-{
-#ifdef CONFIG_JFS_POSIX_ACL
-	struct posix_acl *acl;
-	int rc;
-
-	if (!inode_owner_or_capable(inode))
-		return -EPERM;
-
-	/*
-	 * POSIX_ACL_XATTR_ACCESS is tied to i_mode
-	 */
-	if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0) {
-		acl = posix_acl_from_xattr(&init_user_ns, value, value_len);
-		if (IS_ERR(acl)) {
-			rc = PTR_ERR(acl);
-			printk(KERN_ERR "posix_acl_from_xattr returned %d\n",
-			       rc);
-			return rc;
-		}
-		if (acl) {
-			rc = posix_acl_equiv_mode(acl, &inode->i_mode);
-			posix_acl_release(acl);
-			if (rc < 0) {
-				printk(KERN_ERR
-				       "posix_acl_equiv_mode returned %d\n",
-				       rc);
-				return rc;
-			}
-			mark_inode_dirty(inode);
-		}
-		/*
-		 * We're changing the ACL.  Get rid of the cached one
-		 */
-		forget_cached_acl(inode, ACL_TYPE_ACCESS);
-
-		return 0;
-	} else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0) {
-		acl = posix_acl_from_xattr(&init_user_ns, value, value_len);
-		if (IS_ERR(acl)) {
-			rc = PTR_ERR(acl);
-			printk(KERN_ERR "posix_acl_from_xattr returned %d\n",
-			       rc);
-			return rc;
-		}
-		posix_acl_release(acl);
-
-		/*
-		 * We're changing the default ACL.  Get rid of the cached one
-		 */
-		forget_cached_acl(inode, ACL_TYPE_DEFAULT);
-
-		return 0;
-	}
-#endif			/* CONFIG_JFS_POSIX_ACL */
-	return -EOPNOTSUPP;
-}
-
 /*
  * Most of the permission checking is done by xattr_permission in the vfs.
- * The local file system is responsible for handling the system.* namespace.
  * We also need to verify that this is a namespace that we recognize.
  */
 static int can_set_xattr(struct inode *inode, const char *name,
 			 const void *value, size_t value_len)
 {
-	if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
-		return can_set_system_xattr(inode, name, value, value_len);
-
 	if (!strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN)) {
 		/*
 		 * This makes sure that we aren't trying to set an
@@ -913,6 +844,14 @@ int jfs_setxattr(struct dentry *dentry, const char *name, const void *value,
 	if ((rc = can_set_xattr(inode, name, value, value_len)))
 		return rc;
 
+	/*
+	 * If this is a request for a synthetic attribute in the system.*
+	 * namespace use the generic infrastructure to resolve a handler
+	 * for it via sb->s_xattr.
+	 */
+	if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
+		return generic_setxattr(dentry, name, value, value_len, flags);
+
 	if (value == NULL) {	/* empty EA, do not remove */
 		value = "";
 		value_len = 0;
@@ -986,6 +925,14 @@ ssize_t jfs_getxattr(struct dentry *dentry, const char *name, void *data,
 {
 	int err;
 
+	/*
+	 * If this is a request for a synthetic attribute in the system.*
+	 * namespace use the generic infrastructure to resolve a handler
+	 * for it via sb->s_xattr.
+	 */
+	if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
+		return generic_getxattr(dentry, name, data, buf_size);
+
 	if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
 		/*
 		 * skip past "os2." prefix
@@ -1077,6 +1024,14 @@ int jfs_removexattr(struct dentry *dentry, const char *name)
 	if ((rc = can_set_xattr(inode, name, NULL, 0)))
 		return rc;
 
+	/*
+	 * If this is a request for a synthetic attribute in the system.*
+	 * namespace use the generic infrastructure to resolve a handler
+	 * for it via sb->s_xattr.
+	 */
+	if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
+		return generic_removexattr(dentry, name);
+
 	tid = txBegin(inode->i_sb, 0);
 	mutex_lock(&ji->commit_mutex);
 	rc = __jfs_setxattr(tid, dentry->d_inode, name, NULL, 0, XATTR_REPLACE);
@@ -1088,6 +1043,19 @@ int jfs_removexattr(struct dentry *dentry, const char *name)
 	return rc;
 }
 
+/*
+ * List of handlers for synthetic system.* attributes.  All real ondisk
+ * attributes are handled directly.
+ */
+const struct xattr_handler *jfs_xattr_handlers[] = {
+#ifdef JFS_POSIX_ACL
+	&posix_acl_access_xattr_handler,
+	&posix_acl_default_xattr_handler,
+#endif
+	NULL,
+};
+
+
 #ifdef CONFIG_JFS_SECURITY
 static int jfs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
 			  void *fs_info)