Re: [PATCH] ntfs: avoid incorrectly release for root inode in fill_super

From: Anton Altaparmakov
Date: Fri Jul 25 2014 - 03:47:34 EST


Hi,

NAK

This patch is incorrect. Perhaps you failed to see the ihold() above the d_make_root() call? That means we hold two references on the inode - one from the load_system_files()::ntfs_iget() and one from the ihold() before d_make_root().

Thus in the error code path d_make_root() does iput() which releases one reference and then we do iput() in the error handling path of ntfs_fill_super() which releases the second reference.

Best regards,

Anton

On 25 Jul 2014, at 03:25, Chao Yu <chao2.yu@xxxxxxxxxxx> wrote:

> In d_make_root, when we fail to allocate dentry for root inode, we will iput
> root inode in this function.
> So we do not need to release this inode again at d_make_root's caller.
>
> Signed-off-by: Chao Yu <chao2.yu@xxxxxxxxxxx>
> ---
> fs/ntfs/super.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/fs/ntfs/super.c b/fs/ntfs/super.c
> index 6c3296e..99c5cc6 100644
> --- a/fs/ntfs/super.c
> +++ b/fs/ntfs/super.c
> @@ -2975,7 +2975,11 @@ static int ntfs_fill_super(struct super_block *sb, void *opt, const int silent)
> vol->secure_ino = NULL;
> }
> }
> - iput(vol->root_ino);
> +
> + /*
> + * Just set NULL value here because we have already iput root_ino
> + * in d_make_root.
> + */
> vol->root_ino = NULL;
> iput(vol->lcnbmp_ino);
> vol->lcnbmp_ino = NULL;

--
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
University of Cambridge Information Services, Roger Needham Building
7 JJ Thomson Avenue, Cambridge, CB3 0RB, UK

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