On Jul. 09, 2010, 19:39 +0300, andros@xxxxxxxxxx wrote:
> From: Andy Adamson <andros@xxxxxxxxxx>
>
> We do not free the pnfs_layout_type when the layout segment list is empty, but
> we do remove the layout from the nfs_client cl_layouts list, and we also need
> to re-initialize it. The next LAYOUTGET will set the layout values.
>
> Note: API change: layoutdriver_io_operations free_layout now has a boolean
> to indicate initiaize_only, do not free.
I agree with Boaz that adding a new method (reinit_layout) will be much
better than overloading free_layout.
In any case, having the bool option stating exactly the opposite of
what the function name suggest is quite confusing :)
Benny
>
> Signed-off-by: Andy Adamson <andros@xxxxxxxxxx>
> ---
> fs/nfs/pnfs.c | 30 ++++++++++++++++++++++++++++--
> include/linux/nfs4_pnfs.h | 5 ++++-
> 2 files changed, 32 insertions(+), 3 deletions(-)
>
> diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
> index 6832237..d8887ef 100644
> --- a/fs/nfs/pnfs.c
> +++ b/fs/nfs/pnfs.c
> @@ -337,7 +337,7 @@ put_layout_locked(struct pnfs_layout_type *lo)
>
> dprintk("%s: freeing layout cache %p\n", __func__, lo);
> WARN_ON(!list_empty(&lo->lo_layouts));
> - io_ops->free_layout(lo);
> + io_ops->free_layout(lo, false);
> nfsi->layout = NULL;
> }
> }
> @@ -658,6 +658,31 @@ _pnfs_can_return_lseg(struct pnfs_layout_segment *lseg)
> return atomic_read(&lseg->kref.refcount) == 1;
> }
>
> +/*
> + * We don't free the pnfs_layout_type upon last LAYOUTRETURN, but we do
> + * un-initialize. lo->segs is empty, and the layout has been removed from
> + * lo_layouts. Leave the lo->refcount un-touched.
> + *
> + * Called with inode->i_lock held.
> + *
> + * There still might be an outstanding async LAYOUTCOMMIT, but that's OK
> + * because the pnfs_layout_type is not referenced (exept for the refcount)
> + * by layoutcommit rpc_release.
> + *
> + * Call the layoutdriver free_layout with the initialze-only parameter set
> + * to true.
> + */
> +static void nfs4_uninitialize_layout(struct pnfs_layout_type *lo)
> +{
> + dprintk("--> %s lo->refcount %d\n", __func__, lo->refcount);
> + lo->roc_iomode = 0;
> + pnfs_set_layout_stateid(lo, &zero_stateid);
> + lo->pnfs_layout_state = 0;
> + lo->pnfs_write_begin_pos = 0;
> + lo->pnfs_write_end_pos = 0;
> + /* True means initialize, do not free the layout */
> + PNFS_LD_IO_OPS(lo)->free_layout(lo, true);
> +}
>
> static void
> pnfs_free_layout(struct pnfs_layout_type *lo,
> @@ -686,6 +711,7 @@ pnfs_free_layout(struct pnfs_layout_type *lo,
> spin_lock(&clp->cl_lock);
> list_del_init(&lo->lo_layouts);
> spin_unlock(&clp->cl_lock);
> + nfs4_uninitialize_layout(lo);
> }
>
> dprintk("%s:Return\n", __func__);
> @@ -959,7 +985,7 @@ nfs_lock_alloc_layout(struct inode *ino)
> /* Reference the layout accross i_lock release and grab */
> get_layout(NFS_I(ino)->layout);
> spin_unlock(&ino->i_lock);
> - NFS_SERVER(ino)->pnfs_curr_ld->ld_io_ops->free_layout(new);
> + PNFS_LD_IO_OPS(NFS_I(ino)->layout)->free_layout(new, false);
> spin_lock(&ino->i_lock);
> put_layout_locked(NFS_I(ino)->layout);
> }
> diff --git a/include/linux/nfs4_pnfs.h b/include/linux/nfs4_pnfs.h
> index 2c6ce4c..70e80cd 100644
> --- a/include/linux/nfs4_pnfs.h
> +++ b/include/linux/nfs4_pnfs.h
> @@ -145,7 +145,10 @@ struct layoutdriver_io_operations {
> * inode specific layout structure. Each subsequent layoutget operation results in
> * a set_layout call to set the opaque layout in the layout driver.*/
> struct pnfs_layout_type * (*alloc_layout) (struct inode *inode);
> - void (*free_layout) (struct pnfs_layout_type *);
> +
> + /* init_only true, means do not free the layout, just re-initialize */
> + void (*free_layout) (struct pnfs_layout_type *, bool init_only);
> +
> struct pnfs_layout_segment * (*alloc_lseg) (struct pnfs_layout_type *layoutid, struct nfs4_pnfs_layoutget_res *lgr);
> void (*free_lseg) (struct pnfs_layout_segment *lseg);
>
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