Re: [PATCH 4/5] SQUASHME pnfs-submit embed pnfs_layout_type

[Boaz Harrosh <bharrosh@panasas.com>]

On 06/29/2010 07:42 PM, andros@netapp.com wrote:
> From: Andy Adamson <andros@netapp.com>
> 
> Each layoutdriver embeds the pnfs_layout_type in it's private layout cache
> head structure, and allocates them both with the alloc_layout
> layoutdriver_io_operation.
> 
> Move all nfs inode pnfs field initialization into nfs4_init_once.
> 
> Signed-off-by: Andy Adamson <andros@netapp.com>
> ---
>  fs/nfs/callback_proc.c    |    2 +-
>  fs/nfs/inode.c            |   43 ++++---------------------
>  fs/nfs/nfs4proc.c         |    2 +-
>  fs/nfs/nfs4state.c        |    4 +-
>  fs/nfs/nfs4xdr.c          |    2 +-
>  fs/nfs/pnfs.c             |   78 +++++++++++++++++++++++++--------------------
>  include/linux/nfs4_pnfs.h |   14 ++------
>  include/linux/nfs_fs.h    |    4 +-
>  8 files changed, 61 insertions(+), 88 deletions(-)
> 
> diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
> index 4766695..d999ea8 100644
> --- a/fs/nfs/callback_proc.c
> +++ b/fs/nfs/callback_proc.c
> @@ -233,7 +233,7 @@ static int pnfs_recall_layout(void *data)
>  	rl.cbl_seg.length = NFS4_MAX_UINT64;
>  
>  	if (rl.cbl_recall_type == RETURN_FILE) {
> -		if (pnfs_is_next_layout_stateid(&NFS_I(inode)->layout,
> +		if (pnfs_is_next_layout_stateid(NFS_I(inode)->layout,
>  						rl.cbl_stateid))
>  			status = pnfs_return_layout(inode, &rl.cbl_seg,
>  						    &rl.cbl_stateid, RETURN_FILE,
> diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
> index cb12d33..c290806 100644
> --- a/fs/nfs/inode.c
> +++ b/fs/nfs/inode.c
> @@ -1361,17 +1361,6 @@ void nfs4_clear_inode(struct inode *inode)
>  }
>  #endif
>  
> -static void pnfs_alloc_init_inode(struct nfs_inode *nfsi)
> -{
> -#ifdef CONFIG_NFS_V4_1
> -	memset(&nfsi->layout.stateid, 0, NFS4_STATEID_SIZE);
> -	nfsi->layout.roc_iomode = 0;
> -	nfsi->layout.lo_cred = NULL;
> -	nfsi->layout.pnfs_write_begin_pos = 0;
> -	nfsi->layout.pnfs_write_end_pos = 0;
> -#endif /* CONFIG_NFS_V4_1 */
> -}
> -
>  struct inode *nfs_alloc_inode(struct super_block *sb)
>  {
>  	struct nfs_inode *nfsi;
> @@ -1387,23 +1376,14 @@ struct inode *nfs_alloc_inode(struct super_block *sb)
>  #ifdef CONFIG_NFS_V4
>  	nfsi->nfs4_acl = NULL;
>  #endif /* CONFIG_NFS_V4 */
> -	pnfs_alloc_init_inode(nfsi);
>  	return &nfsi->vfs_inode;
>  }
>  
>  static void pnfs_destroy_inode(struct nfs_inode *nfsi)
>  {
>  #ifdef CONFIG_NFS_V4_1
> -	if (!list_empty(&nfsi->layout.segs))
> +	if (has_layout(nfsi))
>  		pnfs_destroy_layout(nfsi);
> -
> -	WARN_ON(!list_empty(&nfsi->layout.segs));
> -	if (nfsi->layout.refcount)
> -		printk("%s: WARNING: layout.refcount %d\n", __func__,
> -			nfsi->layout.refcount);
> -	WARN_ON(nfsi->layout.refcount);
> -	WARN_ON(!list_empty(&nfsi->layout.lo_layouts));

Andy, these problems did not go away with this patch. Please re-instate
them for the new code. All 3 WARN_ONs still apply. Perhaps in pnfs_destroy_layout()

> -	WARN_ON(nfsi->layout.ld_data);
>  #endif /* CONFIG_NFS_V4_1 */
>  }
>  
> @@ -1415,20 +1395,6 @@ void nfs_destroy_inode(struct inode *inode)
>  	kmem_cache_free(nfs_inode_cachep, nfsi);
>  }
>  
> -static void pnfs_init_once(struct nfs_inode *nfsi)
> -{
> -#ifdef CONFIG_NFS_V4_1
> -	init_waitqueue_head(&nfsi->lo_waitq);
> -	nfsi->pnfs_layout_state = 0;
> -	nfsi->pnfs_layout_suspend = 0;
> -	seqlock_init(&nfsi->layout.seqlock);
> -	INIT_LIST_HEAD(&nfsi->layout.lo_layouts);
> -	INIT_LIST_HEAD(&nfsi->layout.segs);
> -	nfsi->layout.refcount = 0;
> -	nfsi->layout.ld_data = NULL;
> -#endif /* CONFIG_NFS_V4_1 */
> -}
> -
>  static inline void nfs4_init_once(struct nfs_inode *nfsi)
>  {
>  #ifdef CONFIG_NFS_V4
> @@ -1436,6 +1402,12 @@ static inline void nfs4_init_once(struct nfs_inode *nfsi)
>  	nfsi->delegation = NULL;
>  	nfsi->delegation_state = 0;
>  	init_rwsem(&nfsi->rwsem);
> +#ifdef CONFIG_NFS_V4_1
> +	init_waitqueue_head(&nfsi->lo_waitq);
> +	nfsi->layout = NULL;
> +	nfsi->pnfs_layout_state = 0;
> +	nfsi->pnfs_layout_suspend = 0;
> +#endif /* CONFIG_NFS_V4_1 */
>  #endif
>  }
>  
> @@ -1454,7 +1426,6 @@ static void init_once(void *foo)
>  	INIT_HLIST_HEAD(&nfsi->silly_list);
>  	init_waitqueue_head(&nfsi->waitqueue);
>  	nfs4_init_once(nfsi);
> -	pnfs_init_once(nfsi);
>  }
>  
>  static int __init nfs_init_inodecache(void)
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index 6283996..61f4aa9 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -1086,7 +1086,7 @@ static void pnfs4_layout_reclaim(struct nfs4_state *state)
>  	 * flag during grace period
>  	 */
>  	pnfs_destroy_layout(NFS_I(state->inode));
> -	pnfs_set_layout_stateid(&NFS_I(state->inode)->layout, &zero_stateid);
> +	pnfs_set_layout_stateid(NFS_I(state->inode)->layout, &zero_stateid);
>  #endif /* CONFIG_NFS_V4_1 */
>  }
>  
> diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
> index bfe679b..6f44cb0 100644
> --- a/fs/nfs/nfs4state.c
> +++ b/fs/nfs/nfs4state.c
> @@ -597,10 +597,10 @@ static void __nfs4_close(struct path *path, struct nfs4_state *state,
>  #ifdef CONFIG_NFS_V4_1
>  		struct nfs_inode *nfsi = NFS_I(state->inode);
>  
> -		if (has_layout(nfsi) && nfsi->layout.roc_iomode) {
> +		if (has_layout(nfsi) && nfsi->layout->roc_iomode) {
>  			struct nfs4_pnfs_layout_segment range;
>  
> -			range.iomode = nfsi->layout.roc_iomode;
> +			range.iomode = nfsi->layout->roc_iomode;
>  			range.offset = 0;
>  			range.length = NFS4_MAX_UINT64;
>  			pnfs_return_layout(state->inode, &range, NULL,
> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
> index eeee855..0fd02b1 100644
> --- a/fs/nfs/nfs4xdr.c
> +++ b/fs/nfs/nfs4xdr.c
> @@ -1886,7 +1886,7 @@ encode_layoutreturn(struct xdr_stream *xdr,
>  		ld_io_ops->encode_layoutreturn);
>  		if (ld_io_ops->encode_layoutreturn) {
>  			ld_io_ops->encode_layoutreturn(
> -				&NFS_I(args->inode)->layout, xdr, args);
> +				NFS_I(args->inode)->layout, xdr, args);
>  		} else {
>  			p = reserve_space(xdr, 4);
>  			*p = cpu_to_be32(0);
> diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
> index 7f6ace2..9275140 100644
> --- a/fs/nfs/pnfs.c
> +++ b/fs/nfs/pnfs.c
> @@ -153,7 +153,7 @@ pnfs_need_layoutcommit(struct nfs_inode *nfsi, struct nfs_open_context *ctx)
>  	dprintk("%s: has_layout=%d ctx=%p\n", __func__, has_layout(nfsi), ctx);
>  	spin_lock(&nfsi->vfs_inode.i_lock);
>  	if (has_layout(nfsi) && !layoutcommit_needed(nfsi)) {
> -		nfsi->layout.lo_cred = get_rpccred(ctx->state->owner->so_cred);
> +		nfsi->layout->lo_cred = get_rpccred(ctx->state->owner->so_cred);
>  		__set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->pnfs_layout_state);
>  		nfsi->change_attr++;
>  		spin_unlock(&nfsi->vfs_inode.i_lock);
> @@ -174,17 +174,17 @@ pnfs_update_last_write(struct nfs_inode *nfsi, loff_t offset, size_t extent)
>  	loff_t end_pos;
>  
>  	spin_lock(&nfsi->vfs_inode.i_lock);
> -	if (offset < nfsi->layout.pnfs_write_begin_pos)
> -		nfsi->layout.pnfs_write_begin_pos = offset;
> +	if (offset < nfsi->layout->pnfs_write_begin_pos)
> +		nfsi->layout->pnfs_write_begin_pos = offset;
>  	end_pos = offset + extent - 1; /* I'm being inclusive */
> -	if (end_pos > nfsi->layout.pnfs_write_end_pos)
> -		nfsi->layout.pnfs_write_end_pos = end_pos;
> +	if (end_pos > nfsi->layout->pnfs_write_end_pos)
> +		nfsi->layout->pnfs_write_end_pos = end_pos;
>  	dprintk("%s: Wrote %lu@%lu bpos %lu, epos: %lu\n",
>  		__func__,
>  		(unsigned long) extent,
>  		(unsigned long) offset ,
> -		(unsigned long) nfsi->layout.pnfs_write_begin_pos,
> -		(unsigned long) nfsi->layout.pnfs_write_end_pos);
> +		(unsigned long) nfsi->layout->pnfs_write_begin_pos,
> +		(unsigned long) nfsi->layout->pnfs_write_end_pos);
>  	spin_unlock(&nfsi->vfs_inode.i_lock);
>  }
>  
> @@ -325,10 +325,9 @@ get_layout(struct pnfs_layout_type *lo)
>  static inline struct pnfs_layout_type *
>  grab_current_layout(struct nfs_inode *nfsi)
>  {
> -	struct pnfs_layout_type *lo = &nfsi->layout;
> +	struct pnfs_layout_type *lo = nfsi->layout;
>  
> -	BUG_ON_UNLOCKED_LO(lo);

Why did you drop this one?

> -	if (!lo->ld_data)
> +	if (!lo)
>  		return NULL;
>  	get_layout(lo);
>  	return lo;
> @@ -342,13 +341,13 @@ put_layout(struct pnfs_layout_type *lo)
>  
>  	lo->refcount--;
>  	if (!lo->refcount) {
> -		struct layoutdriver_io_operations *io_ops =
> -			PNFS_LD_IO_OPS(lo);
> +		struct layoutdriver_io_operations *io_ops = PNFS_LD_IO_OPS(lo);
> +		struct nfs_inode *nfsi = PNFS_NFS_INODE(lo);
>  
> -		dprintk("%s: freeing layout %p\n", __func__, lo->ld_data);
> +		dprintk("%s: freeing layout cache %p\n", __func__, lo);
>  		WARN_ON(!list_empty(&lo->lo_layouts));
> -		io_ops->free_layout(lo->ld_data);
> -		lo->ld_data = NULL;
> +		io_ops->free_layout(lo);
> +		nfsi->layout = NULL;
>  	}
>  }
>  
> @@ -688,7 +687,7 @@ pnfs_return_layout_barrier(struct nfs_inode *nfsi,
>  	bool ret = false;
>  
>  	spin_lock(&nfsi->vfs_inode.i_lock);
> -	list_for_each_entry (lseg, &nfsi->layout.segs, fi_list) {
> +	list_for_each_entry(lseg, &nfsi->layout->segs, fi_list) {

White space cleanup. actually I like the space. I thought checkpatch
was fixed to accept these spaces?

>  		if (!should_free_lseg(lseg, range))
>  			continue;
>  		lseg->valid = false;
> @@ -894,17 +893,20 @@ pnfs_insert_layout(struct pnfs_layout_type *lo,
>  	dprintk("%s:Return\n", __func__);
>  }
>  
> +/*
> + * Each layoutdriver embeds pnfs_layout_type in it's per-layout type layout
> + * cache structure. Initialize the common pnfs_layout_type fields.
> + */
>  static struct pnfs_layout_type *
>  alloc_init_layout(struct inode *ino)
>  {
> -	void *ld_data;
>  	struct pnfs_layout_type *lo;
>  	struct layoutdriver_io_operations *io_ops;
>  
>  	io_ops = NFS_SERVER(ino)->pnfs_curr_ld->ld_io_ops;
> -	lo = &NFS_I(ino)->layout;
> -	ld_data = io_ops->alloc_layout(ino);
> -	if (!ld_data) {
> +	lo = NFS_I(ino)->layout;
> +	lo = io_ops->alloc_layout(ino);

Oops, ;-)

> +	if (!lo) {
>  		printk(KERN_ERR
>  			"%s: out of memory: io_ops->alloc_layout failed\n",
>  			__func__);
> @@ -912,11 +914,17 @@ alloc_init_layout(struct inode *ino)
>  	}
>  
>  	spin_lock(&ino->i_lock);
> -	BUG_ON(lo->ld_data != NULL);

You could still do a BUG_ON(nfsi->layout) above before the io_ops->alloc_layout(ino)
call.

> -	lo->ld_data = ld_data;
> -	memset(&lo->stateid, 0, NFS4_STATEID_SIZE);
>  	lo->refcount = 1;
> +	INIT_LIST_HEAD(&lo->lo_layouts);
> +	INIT_LIST_HEAD(&lo->segs);
>  	lo->roc_iomode = 0;
> +	seqlock_init(&lo->seqlock);

All these below, I'd drop. The comment above io_ops->alloc_layout should
say that it must return a ZEROed out structure, which it is in your
files-layout patch.

> +	memset(&lo->stateid, 0, NFS4_STATEID_SIZE);
> +	lo->lo_cred = NULL;
> +	lo->pnfs_write_begin_pos = 0;
> +	lo->pnfs_write_end_pos = 0;

> +	lo->lo_inode = ino;
> +	NFS_I(ino)->layout = lo;
>  	spin_unlock(&ino->i_lock);

Just as a note:
  A pointer/word atomic inspection theory is based on the fact that the set is
  done with a memory barrier. Same as the test/set_bit operations. So here
  the spin_unlock provides that for us, naturally. (*Not* that the inode state will
  really need it, because no one will actually care before the allocation is done)

>  	return lo;
>  }
> @@ -962,7 +970,7 @@ get_lock_alloc_layout(struct inode *ino)
>  		/* Was current_layout already allocated while we slept?
>  		 * If so, retry get_lock'ing it. Otherwise, allocate it.
>  		 */
> -		if (nfsi->layout.ld_data) {
> +		if (nfsi->layout) {
>  			spin_lock(&ino->i_lock);
>  			continue;
>  		}
> @@ -1312,7 +1320,7 @@ pnfs_set_pg_test(struct inode *inode, struct nfs_pageio_descriptor *pgio)
>  
>  	pgio->pg_test = NULL;
>  
> -	laytype = &NFS_I(inode)->layout;
> +	laytype = NFS_I(inode)->layout;
>  	ld = NFS_SERVER(inode)->pnfs_curr_ld;
>  	if (!pnfs_enabled_sb(NFS_SERVER(inode)) || !laytype)
>  		return;
> @@ -1445,7 +1453,7 @@ pnfs_writepages(struct nfs_write_data *wdata, int how)
>  		numpages);
>  	wdata->pdata.lseg = lseg;
>  	trypnfs = nfss->pnfs_curr_ld->ld_io_ops->write_pagelist(
> -							&nfsi->layout,
> +							nfsi->layout,
>  							args->pages,
>  							args->pgbase,
>  							numpages,
> @@ -1498,7 +1506,7 @@ pnfs_readpages(struct nfs_read_data *rdata)
>  		__func__, numpages);
>  	rdata->pdata.lseg = lseg;
>  	trypnfs = nfss->pnfs_curr_ld->ld_io_ops->read_pagelist(
> -							&nfsi->layout,
> +							nfsi->layout,
>  							args->pages,
>  							args->pgbase,
>  							numpages,
> @@ -1559,7 +1567,7 @@ pnfs_commit(struct nfs_write_data *data, int sync)
>  	 * This will be done by passing the buck to the layout driver.
>  	 */
>  	data->pdata.lseg = NULL;
> -	trypnfs = nfss->pnfs_curr_ld->ld_io_ops->commit(&nfsi->layout,
> +	trypnfs = nfss->pnfs_curr_ld->ld_io_ops->commit(nfsi->layout,
>  							sync, data);
>  	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
>  	return trypnfs;
> @@ -1630,14 +1638,14 @@ pnfs_layoutcommit_inode(struct inode *inode, int sync)
>  	/* Clear layoutcommit properties in the inode so
>  	 * new lc info can be generated
>  	 */
> -	write_begin_pos = nfsi->layout.pnfs_write_begin_pos;
> -	write_end_pos = nfsi->layout.pnfs_write_end_pos;
> -	data->cred = nfsi->layout.lo_cred;
> -	nfsi->layout.pnfs_write_begin_pos = 0;
> -	nfsi->layout.pnfs_write_end_pos = 0;
> -	nfsi->layout.lo_cred = NULL;
> +	write_begin_pos = nfsi->layout->pnfs_write_begin_pos;
> +	write_end_pos = nfsi->layout->pnfs_write_end_pos;
> +	data->cred = nfsi->layout->lo_cred;
> +	nfsi->layout->pnfs_write_begin_pos = 0;
> +	nfsi->layout->pnfs_write_end_pos = 0;
> +	nfsi->layout->lo_cred = NULL;
>  	__clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->pnfs_layout_state);
> -	pnfs_get_layout_stateid(&data->args.stateid, &nfsi->layout);
> +	pnfs_get_layout_stateid(&data->args.stateid, nfsi->layout);
>  
>  	spin_unlock(&inode->i_lock);
>  
> diff --git a/include/linux/nfs4_pnfs.h b/include/linux/nfs4_pnfs.h
> index 4d9b15c..6e46589 100644
> --- a/include/linux/nfs4_pnfs.h
> +++ b/include/linux/nfs4_pnfs.h
> @@ -35,13 +35,13 @@ struct pnfs_layoutdriver_type {
>  static inline struct nfs_inode *
>  PNFS_NFS_INODE(struct pnfs_layout_type *lo)
>  {
> -	return container_of(lo, struct nfs_inode, layout);
> +	return NFS_I(lo->lo_inode);
>  }
>  
>  static inline struct inode *
>  PNFS_INODE(struct pnfs_layout_type *lo)
>  {
> -	return &PNFS_NFS_INODE(lo)->vfs_inode;
> +	return lo->lo_inode;
>  }
>  
>  static inline struct nfs_server *
> @@ -50,12 +50,6 @@ PNFS_NFS_SERVER(struct pnfs_layout_type *lo)
>  	return NFS_SERVER(PNFS_INODE(lo));
>  }
>  
> -static inline void *
> -PNFS_LD_DATA(struct pnfs_layout_type *lo)
> -{
> -	return lo->ld_data;
> -}
> -
>  static inline struct pnfs_layoutdriver_type *
>  PNFS_LD(struct pnfs_layout_type *lo)
>  {
> @@ -77,7 +71,7 @@ PNFS_LD_POLICY_OPS(struct pnfs_layout_type *lo)
>  static inline bool
>  has_layout(struct nfs_inode *nfsi)
>  {
> -	return nfsi->layout.ld_data != NULL;
> +	return nfsi->layout != NULL;
>  }
>  
>  static inline bool
> @@ -149,7 +143,7 @@ struct layoutdriver_io_operations {
>  	/* Layout information. For each inode, alloc_layout is executed once to retrieve an
>  	 * inode specific layout structure.  Each subsequent layoutget operation results in
>  	 * a set_layout call to set the opaque layout in the layout driver.*/
> -	void * (*alloc_layout) (struct inode *inode);
> +	struct pnfs_layout_type * (*alloc_layout) (struct inode *inode);
>  	void (*free_layout) (void *layoutid);
>  	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);
> diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
> index cebc958..43d516e 100644
> --- a/include/linux/nfs_fs.h
> +++ b/include/linux/nfs_fs.h
> @@ -104,13 +104,13 @@ struct pnfs_layout_type {
>  	int roc_iomode;			/* iomode to return on close, 0=none */
>  	seqlock_t seqlock;		/* Protects the stateid */
>  	nfs4_stateid stateid;
> -	void *ld_data;			/* layout driver private data */
>  	struct rpc_cred         *lo_cred; /* layoutcommit credential */
>  	/* DH: These vars keep track of the maximum write range
>  	 * so the values can be used for layoutcommit.
>  	 */
>  	loff_t                  pnfs_write_begin_pos;
>  	loff_t                  pnfs_write_end_pos;
> +	struct inode		*lo_inode;
>  };
>  
>  /*
> @@ -201,7 +201,7 @@ struct nfs_inode {
>  	/* pNFS layout information */
>  #if defined(CONFIG_NFS_V4_1)
>  	wait_queue_head_t lo_waitq;
> -	struct pnfs_layout_type layout;
> +	struct pnfs_layout_type *layout;
>  	unsigned long pnfs_layout_state;
>  	#define NFS_INO_RO_LAYOUT_FAILED 0 /* ro LAYOUTGET failed stop trying */
>  	#define NFS_INO_RW_LAYOUT_FAILED 1 /* rw LAYOUTGET failed stop trying */

Boaz