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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>
This commit is contained in:
Theodore Ts'o 2023-05-06 21:04:01 -04:00
parent 4c0b4818b1
commit f4ce24f54d
1 changed files with 2 additions and 1 deletions
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3
fs/ext4/inline.c
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@ -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);