Re: [syzbot] [hfs?] possible deadlock in hfs_extend_file (2)

[Edward Adam Davis]

please test possible deadlock in hfs_extend_file

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 610a9b8f49fb

diff --git a/fs/hfs/extent.c b/fs/hfs/extent.c
index 6d1878b99b30..1b02c7b6a10c 100644
--- a/fs/hfs/extent.c
+++ b/fs/hfs/extent.c
@@ -197,6 +197,10 @@ static int hfs_ext_read_extent(struct inode *inode, u16 block)
 	    block < HFS_I(inode)->cached_start + HFS_I(inode)->cached_blocks)
 		return 0;
 
+	if (HFS_I(inode)->flags & HFS_FLG_EXT_DIRTY && 
+	    HFS_I(inode)->flags & HFS_FLG_EXT_NEW) 
+		return -ENOENT;
+
 	res = hfs_find_init(HFS_SB(inode->i_sb)->ext_tree, &fd);
 	if (!res) {
 		res = __hfs_ext_cache_extent(&fd, inode, block);