FAILED: patch "[PATCH] ext4: fix deadlock when converting an inline directory in" failed to apply to 4.19-stable tree

FAILED: patch "[PATCH] ext4: fix deadlock when converting an inline directory in" failed to apply to 4.19-stable tree

[gregkh]

The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y
git checkout FETCH_HEAD
git cherry-pick -x f4ce24f54d9cca4f09a395f3eecce20d6bec4663
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2023051540-afterlife-impeding-8523@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..

Possible dependencies:

f4ce24f54d9c ("ext4: fix deadlock when converting an inline directory in nojournal mode")
f036adb39976 ("ext4: rename "dirent_csum" functions to use "dirblock"")
b886ee3e778e ("ext4: Support case-insensitive file name lookups")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From f4ce24f54d9cca4f09a395f3eecce20d6bec4663 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso@mit.edu>
Date: Sat, 6 May 2023 21:04:01 -0400
Subject: [PATCH] ext4: fix deadlock when converting an inline directory in
 nojournal mode

In no journal mode, ext4_finish_convert_inline_dir() can self-deadlock
by calling ext4_handle_dirty_dirblock() when it already has taken the
directory lock.  There is a similar self-deadlock in
ext4_incvert_inline_data_nolock() for data files which we'll fix at
the same time.

A simple reproducer demonstrating the problem:

    mke2fs -Fq -t ext2 -O inline_data -b 4k /dev/vdc 64
    mount -t ext4 -o dirsync /dev/vdc /vdc
    cd /vdc
    mkdir file0
    cd file0
    touch file0
    touch file1
    attr -s BurnSpaceInEA -V abcde .
    touch supercalifragilisticexpialidocious

Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230507021608.1290720-1-tytso@mit.edu
Reported-by: syzbot+91dccab7c64e2850a4e5@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=ba84cc80a9491d65416bc7877e1650c87530fe8a
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 859bc4e2c9b0..d3dfc51a43c5 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -1175,6 +1175,7 @@ static int ext4_finish_convert_inline_dir(handle_t *handle,
 		ext4_initialize_dirent_tail(dir_block,
 					    inode->i_sb->s_blocksize);
 	set_buffer_uptodate(dir_block);
+	unlock_buffer(dir_block);
 	err = ext4_handle_dirty_dirblock(handle, inode, dir_block);
 	if (err)
 		return err;
@@ -1249,6 +1250,7 @@ static int ext4_convert_inline_data_nolock(handle_t *handle,
 	if (!S_ISDIR(inode->i_mode)) {
 		memcpy(data_bh->b_data, buf, inline_size);
 		set_buffer_uptodate(data_bh);
+		unlock_buffer(data_bh);
 		error = ext4_handle_dirty_metadata(handle,
 						   inode, data_bh);
 	} else {
@@ -1256,7 +1258,6 @@ static int ext4_convert_inline_data_nolock(handle_t *handle,
 						       buf, inline_size);
 	}
 
-	unlock_buffer(data_bh);
 out_restore:
 	if (error)
 		ext4_restore_inline_data(handle, inode, iloc, buf, inline_size);