1 files changed, 94 insertions, 21 deletions

diff --git a/drivers/staging/erofs/xattr.c b/drivers/staging/erofs/xattr.c
index 80dca6a4adbe..f716ab0446e5 100644
--- a/drivers/staging/erofs/xattr.c
+++ b/drivers/staging/erofs/xattr.c
@@ -44,19 +44,48 @@ static inline void xattr_iter_end_final(struct xattr_iter *it)
 
 static int init_inode_xattrs(struct inode *inode)
 {
+	struct erofs_vnode *const vi = EROFS_V(inode);
 	struct xattr_iter it;
 	unsigned int i;
 	struct erofs_xattr_ibody_header *ih;
 	struct super_block *sb;
 	struct erofs_sb_info *sbi;
-	struct erofs_vnode *vi;
 	bool atomic_map;
+	int ret = 0;
 
-	if (likely(inode_has_inited_xattr(inode)))
+	/* the most case is that xattrs of this inode are initialized. */
+	if (test_bit(EROFS_V_EA_INITED_BIT, &vi->flags))
 		return 0;
 
-	vi = EROFS_V(inode);
-	BUG_ON(!vi->xattr_isize);
+	if (wait_on_bit_lock(&vi->flags, EROFS_V_BL_XATTR_BIT, TASK_KILLABLE))
+		return -ERESTARTSYS;
+
+	/* someone has initialized xattrs for us? */
+	if (test_bit(EROFS_V_EA_INITED_BIT, &vi->flags))
+		goto out_unlock;
+
+	/*
+	 * bypass all xattr operations if ->xattr_isize is not greater than
+	 * sizeof(struct erofs_xattr_ibody_header), in detail:
+	 * 1) it is not enough to contain erofs_xattr_ibody_header then
+	 *    ->xattr_isize should be 0 (it means no xattr);
+	 * 2) it is just to contain erofs_xattr_ibody_header, which is on-disk
+	 *    undefined right now (maybe use later with some new sb feature).
+	 */
+	if (vi->xattr_isize == sizeof(struct erofs_xattr_ibody_header)) {
+		errln("xattr_isize %d of nid %llu is not supported yet",
+		      vi->xattr_isize, vi->nid);
+		ret = -ENOTSUPP;
+		goto out_unlock;
+	} else if (vi->xattr_isize < sizeof(struct erofs_xattr_ibody_header)) {
+		if (unlikely(vi->xattr_isize)) {
+			DBG_BUGON(1);
+			ret = -EIO;
+			goto out_unlock;	/* xattr ondisk layout error */
+		}
+		ret = -ENOATTR;
+		goto out_unlock;
+	}
 
 	sb = inode->i_sb;
 	sbi = EROFS_SB(sb);
@@ -64,8 +93,10 @@ static int init_inode_xattrs(struct inode *inode)
 	it.ofs = erofs_blkoff(iloc(sbi, vi->nid) + vi->inode_isize);
 
 	it.page = erofs_get_inline_page(inode, it.blkaddr);
-	if (IS_ERR(it.page))
-		return PTR_ERR(it.page);
+	if (IS_ERR(it.page)) {
+		ret = PTR_ERR(it.page);
+		goto out_unlock;
+	}
 
 	/* read in shared xattr array (non-atomic, see kmalloc below) */
 	it.kaddr = kmap(it.page);
@@ -78,7 +109,8 @@ static int init_inode_xattrs(struct inode *inode)
 						sizeof(uint), GFP_KERNEL);
 	if (vi->xattr_shared_xattrs == NULL) {
 		xattr_iter_end(&it, atomic_map);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto out_unlock;
 	}
 
 	/* let's skip ibody header */
@@ -92,8 +124,12 @@ static int init_inode_xattrs(struct inode *inode)
 
 			it.page = erofs_get_meta_page(sb,
 				++it.blkaddr, S_ISDIR(inode->i_mode));
-			if (IS_ERR(it.page))
-				return PTR_ERR(it.page);
+			if (IS_ERR(it.page)) {
+				kfree(vi->xattr_shared_xattrs);
+				vi->xattr_shared_xattrs = NULL;
+				ret = PTR_ERR(it.page);
+				goto out_unlock;
+			}
 
 			it.kaddr = kmap_atomic(it.page);
 			atomic_map = true;
@@ -105,8 +141,11 @@ static int init_inode_xattrs(struct inode *inode)
 	}
 	xattr_iter_end(&it, atomic_map);
 
-	inode_set_inited_xattr(inode);
-	return 0;
+	set_bit(EROFS_V_EA_INITED_BIT, &vi->flags);
+
+out_unlock:
+	clear_and_wake_up_bit(EROFS_V_BL_XATTR_BIT, &vi->flags);
+	return ret;
 }
 
 /*
@@ -117,10 +156,12 @@ static int init_inode_xattrs(struct inode *inode)
  *                            and need to be handled
  */
 struct xattr_iter_handlers {
-	int (*entry)(struct xattr_iter *, struct erofs_xattr_entry *);
-	int (*name)(struct xattr_iter *, unsigned int, char *, unsigned int);
-	int (*alloc_buffer)(struct xattr_iter *, unsigned int);
-	void (*value)(struct xattr_iter *, unsigned int, char *, unsigned int);
+	int (*entry)(struct xattr_iter *_it, struct erofs_xattr_entry *entry);
+	int (*name)(struct xattr_iter *_it, unsigned int processed, char *buf,
+		    unsigned int len);
+	int (*alloc_buffer)(struct xattr_iter *_it, unsigned int value_sz);
+	void (*value)(struct xattr_iter *_it, unsigned int processed, char *buf,
+		      unsigned int len);
 };
 
 static inline int xattr_iter_fixup(struct xattr_iter *it)
@@ -422,7 +463,6 @@ static int erofs_xattr_generic_get(const struct xattr_handler *handler,
 		struct dentry *unused, struct inode *inode,
 		const char *name, void *buffer, size_t size)
 {
-	struct erofs_vnode *const vi = EROFS_V(inode);
 	struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
 
 	switch (handler->flags) {
@@ -440,9 +480,6 @@ static int erofs_xattr_generic_get(const struct xattr_handler *handler,
 		return -EINVAL;
 	}
 
-	if (!vi->xattr_isize)
-		return -ENOATTR;
-
 	return erofs_getxattr(inode, handler->flags, name, buffer, size);
 }
 
@@ -503,8 +540,7 @@ static int xattr_entrylist(struct xattr_iter *_it,
 	if (h == NULL || (h->list != NULL && !h->list(it->dentry)))
 		return 1;
 
-	/* Note that at least one of 'prefix' and 'name' should be non-NULL */
-	prefix = h->prefix != NULL ? h->prefix : h->name;
+	prefix = xattr_prefix(h);
 	prefix_len = strlen(prefix);
 
 	if (it->buffer == NULL) {
@@ -627,3 +663,40 @@ ssize_t erofs_listxattr(struct dentry *dentry,
 	return shared_listxattr(&it);
 }
 
+#ifdef CONFIG_EROFS_FS_POSIX_ACL
+struct posix_acl *erofs_get_acl(struct inode *inode, int type)
+{
+	struct posix_acl *acl;
+	int prefix, rc;
+	char *value = NULL;
+
+	switch (type) {
+	case ACL_TYPE_ACCESS:
+		prefix = EROFS_XATTR_INDEX_POSIX_ACL_ACCESS;
+		break;
+	case ACL_TYPE_DEFAULT:
+		prefix = EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT;
+		break;
+	default:
+		return ERR_PTR(-EINVAL);
+	}
+
+	rc = erofs_getxattr(inode, prefix, "", NULL, 0);
+	if (rc > 0) {
+		value = kmalloc(rc, GFP_KERNEL);
+		if (!value)
+			return ERR_PTR(-ENOMEM);
+		rc = erofs_getxattr(inode, prefix, "", value, rc);
+	}
+
+	if (rc == -ENOATTR)
+		acl = NULL;
+	else if (rc < 0)
+		acl = ERR_PTR(rc);
+	else
+		acl = posix_acl_from_xattr(&init_user_ns, value, rc);
+	kfree(value);
+	return acl;
+}
+#endif
+