[PATCH 4.9 03/56] f2fs: fix a bug caused by NULL extent tree

Greg Kroah-Hartman
2018-03-02T08:56:11Z

From: Yunlei He <heyunlei@huawei.com>

commit dad48e73127ba10279ea33e6dbc8d3905c4d31c0 upstream.

Thread A: Thread B:

-f2fs_remount
-sbi->mount_opt.opt = 0;
<--- -f2fs_iget
-do_read_inode
-f2fs_init_extent_tree
-F2FS_I(inode)->extent_tree is NULL
-default_options && parse_options
-remount return
<--- -f2fs_map_blocks
-f2fs_lookup_extent_tree
-f2fs_bug_on(sbi, !et);

The same problem with f2fs_new_inode.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/f2fs/extent_cache.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

--- a/fs/f2fs/extent_cache.c
+++ b/fs/f2fs/extent_cache.c
@@ -177,7 +177,7 @@ static void __drop_largest_extent(struct
}

/* return true, if inode page is changed */
-bool f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext)
+static bool __f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext)
{
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
struct extent_tree *et;
@@ -215,6 +215,16 @@ out:
return false;
}

+bool f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext)
+{
+ bool ret = __f2fs_init_extent_tree(inode, i_ext);
+
+ if (!F2FS_I(inode)->extent_tree)
+ set_inode_flag(inode, FI_NO_EXTENT);
+
+ return ret;
+}
+
static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
struct extent_info *ei)
{