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| author | Theodore Ts'o <tytso@mit.edu> | 2023-05-06 21:04:01 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2023-05-13 18:05:05 -0400 |
| commit | f4ce24f54d9cca4f09a395f3eecce20d6bec4663 (patch) | |
| tree | 236dd40a035004bf3a07896147cd1ae102ad3a5a /fs | |
| parent | 4c0b4818b1f636bc96359f7817a2d8bab6370162 (diff) | |
| download | lwn-f4ce24f54d9cca4f09a395f3eecce20d6bec4663.tar.gz lwn-f4ce24f54d9cca4f09a395f3eecce20d6bec4663.zip | |
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>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/inline.c | 3 |
1 files changed, 2 insertions, 1 deletions
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); |