This is a note to let you know that I've just added the patch titled

f2fs: fix a bug caused by NULL extent tree

to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: f2fs-fix-a-bug-caused-by-null-extent-tree.patch and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From dad48e73127ba10279ea33e6dbc8d3905c4d31c0 Mon Sep 17 00:00:00 2001

From: Yunlei He heyunlei@huawei.com Date: Fri, 19 May 2017 15:06:12 +0800 Subject: f2fs: fix a bug caused by NULL extent tree

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 | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)

--- a/fs/f2fs/extent_cache.c +++ b/fs/f2fs/extent_cache.c @@ -172,7 +172,7 @@ void f2fs_drop_largest_extent(struct ino __drop_largest_extent(inode, fofs, 1); }

-void f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext) +static void __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; @@ -204,6 +204,14 @@ out: write_unlock(&et->lock); }

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

Patches currently in stable-queue which might be from heyunlei@huawei.com are

queue-4.4/f2fs-fix-a-bug-caused-by-null-extent-tree.patch