On 3/8/2017 03:30, Jaegeuk Kim wrote:
> Hi Kinglong,
>
> Can we make a testcase in xfstests to check this clearly?
> 1. creat A under encrypted dir
> 2. rename A to B
> 3. fsync B
> 4. power-cut
>
> Is this your concern?
Yes, it is.
If B isn't exist, rename A to B means create a new A (unlink the old).
B is exist, the inode (include disk node) will be replace by A, but,
for the file_enc_name, the disk i_name/i_namelen isn't updated.
For the rename, A and B lost there parent, so the 3 step will cause checkpoint,
after that, everything is updated to disk (with the unchanged filename),
so that the 4 step of power-cut can't cause a roll_forward.
If fsync A for flags the inode and then rename as,
1. creat A and B under encrypted dir
2. fsync A (after rename, B will be unlink)
3. rename A to B
4. godown
5. umount/mount
A roll_forward (recover_dentry) happens, the result is same as after setp1,
that's not my needs.
For the IS_CHECKPOINTED flag, after a new created file sync to the disk,
it's cleared, and never appears again, after that a roll_forward of
recover_dentry will never happen (it means the disk i_name will not be
used forever). Am I right?
If that's right, next update_dent_inode after file created is useless,
we can remove them include the FADVISE_ENC_NAME_BIT.
>
> Hmm, on-disk filename is used when doing roll-forward recovery, and it seems
> there is a hole in try_to_fix_pino() to recover its pino without filename.
>
> Like this?
>
>>From 7efde035d9f930fc63c30b25327e870b021750f3 Mon Sep 17 00:00:00 2001
> From: Jaegeuk Kim <jaeg...@kernel.org>
> Date: Tue, 7 Mar 2017 11:22:45 -0800
> Subject: [PATCH] f2fS: don't allow to get pino when filename is encrypted
>
> After renaming an encrypted file, we have no way to get its
> encrypted filename from its dentry.
>
> Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org>
> ---
> fs/f2fs/file.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index e0b2378f8519..852195b3bcce 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -110,6 +110,9 @@ static int get_parent_ino(struct inode *inode, nid_t
> *pino)
> {
> struct dentry *dentry;
>
> + if (file_enc_name(inode))
> + return 0;
> +
> inode = igrab(inode);
> dentry = d_find_any_alias(inode);
> iput(inode);
>
The renamed inode will lost their parent ino, and try to fix it when fsync.
With the file_enc_name checking, get_parent_ino return 0 without parent ino
for encrypted inode, after that the FADVISE_COLD_BIT will exist forever,
fsync the encrypted inode causing do_checkpoint every time.
static void try_to_fix_pino(struct inode *inode)
{
struct f2fs_inode_info *fi = F2FS_I(inode);
nid_t pino;
down_write(&fi->i_sem);
if (file_wrong_pino(inode) && inode->i_nlink == 1 &&
get_parent_ino(inode, &pino)) {
f2fs_i_pino_write(inode, pino);
file_got_pino(inode);
}
up_write(&fi->i_sem);
}
thanks,
Kinglong Mee
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