On Wed, Jul 27, 2022 at 05:57:53PM +0200, Jan Kara wrote: > When inode is created and written to using direct IO, there is nothing > to clear the EXT4_STATE_MAY_INLINE_DATA flag. Thus when inode gets > truncated later to say 1 byte and written using normal write, we will > try to store the data as inline data. This confuses the code later > because the inode now has both normal block and inline data allocated > and the confusion manifests for example as: > > kernel BUG at fs/ext4/inode.c:2721! > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > CPU: 0 PID: 359 Comm: repro Not tainted 5.19.0-rc8-00001-g31ba1e3b8305-dirty #15 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014 > RIP: 0010:ext4_writepages+0x363d/0x3660 > RSP: 0018:ffffc90000ccf260 EFLAGS: 00010293 > RAX: ffffffff81e1abcd RBX: 0000008000000000 RCX: ffff88810842a180 > RDX: 0000000000000000 RSI: 0000008000000000 RDI: 0000000000000000 > RBP: ffffc90000ccf650 R08: ffffffff81e17d58 R09: ffffed10222c680b > R10: dfffe910222c680c R11: 1ffff110222c680a R12: ffff888111634128 > R13: ffffc90000ccf880 R14: 0000008410000000 R15: 0000000000000001 > FS: 00007f72635d2640(0000) GS:ffff88811b000000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000565243379180 CR3: 000000010aa74000 CR4: 0000000000150eb0 > Call Trace: > <TASK> > do_writepages+0x397/0x640 > filemap_fdatawrite_wbc+0x151/0x1b0 > file_write_and_wait_range+0x1c9/0x2b0 > ext4_sync_file+0x19e/0xa00 > vfs_fsync_range+0x17b/0x190 > ext4_buffered_write_iter+0x488/0x530 > ext4_file_write_iter+0x449/0x1b90 > vfs_write+0xbcd/0xf40 > ksys_write+0x198/0x2c0 > __x64_sys_write+0x7b/0x90 > do_syscall_64+0x3d/0x90 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > </TASK> > > Fix the problem by clearing EXT4_STATE_MAY_INLINE_DATA when we are doing > direct IO write to a file. Looks good, thanks. Reviewed-by: Lukas Czerner <lczerner@xxxxxxxxxx> > > Reported-by: Tadeusz Struk <tadeusz.struk@xxxxxxxxxx> > Reported-by: syzbot+bd13648a53ed6933ca49@xxxxxxxxxxxxxxxxxxxxxxxxx > Link: https://syzkaller.appspot.com/bug?id=a1e89d09bbbcbd5c4cb45db230ee28c822953984 > Signed-off-by: Jan Kara <jack@xxxxxxx> > --- > fs/ext4/file.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/fs/ext4/file.c b/fs/ext4/file.c > index 109d07629f81..cab5dfed1cd6 100644 > --- a/fs/ext4/file.c > +++ b/fs/ext4/file.c > @@ -528,6 +528,12 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from) > ret = -EAGAIN; > goto out; > } > + /* > + * Make sure inline data cannot be created anymore since we are going > + * to allocate blocks for DIO. We know the inode does not have any > + * inline data now because ext4_dio_supported() checked for that. > + */ > + ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); > > offset = iocb->ki_pos; > count = ret; > -- > 2.35.3 >
