1 files changed, 50 insertions, 15 deletions

diff --git a/drivers/staging/erofs/xattr.c b/drivers/staging/erofs/xattr.c
index 80dca6a4adbe..6cb05ae31233 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;
 }
 
 /*
@@ -422,7 +461,6 @@ 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 +478,6 @@ 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);
 }