Re: [PATCH 2/3] staging: lustre: lmv: correctly iput lmo_root

[James Simmons]

> Commit 8f18c8a48b73 ("staging: lustre: lmv: separate master object
> with master stripe") changed how lmo_root inodes were managed,
> particularly when LMV_HASH_FLAG_MIGRATION is not set.
> Previously lsm_md_oinfo[0].lmo_root was always a borrowed
> inode reference and didn't need to by iput().
> Since the change, that special case only applies when
> LMV_HASH_FLAG_MIGRATION is set
> 
> In the upstream (lustre-release) version of this patch [Commit
> 60e07b972114 ("LU-4690 lod: separate master object with master
> stripe")] the for loop in the lmv_unpack_md() was changed to count
> from 0 and to ignore entry 0 if LMV_HASH_FLAG_MIGRATION is set.
> In the patch that got applied to Linux, that change was missing,
> so lsm_md_oinfo[0].lmo_root is never iput().
> This results in a "VFS: Busy inodes" warning at unmount.
> 
> Fixes: 8f18c8a48b73 ("staging: lustre: lmv: separate master object with master stripe")
> Signed-off-by: NeilBrown <neilb@xxxxxxxx>

Reviewed-by: James Simmons <jsimmons@xxxxxxxxxxxxx>


> ---
>  drivers/staging/lustre/lustre/lmv/lmv_obd.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/lustre/lustre/lmv/lmv_obd.c b/drivers/staging/lustre/lustre/lmv/lmv_obd.c
> index 179651531862..e8a9b9902c37 100644
> --- a/drivers/staging/lustre/lustre/lmv/lmv_obd.c
> +++ b/drivers/staging/lustre/lustre/lmv/lmv_obd.c
> @@ -2695,7 +2695,7 @@ static int lmv_unpackmd(struct obd_export *exp, struct lmv_stripe_md **lsmp,
>  	if (lsm && !lmm) {
>  		int i;
>  
> -		for (i = 1; i < lsm->lsm_md_stripe_count; i++) {
> +		for (i = 0; i < lsm->lsm_md_stripe_count; i++) {
>  			/*
>  			 * For migrating inode, the master stripe and master
>  			 * object will be the same, so do not need iput, see
> 
> 
>