On 06/29/2010 07:42 PM, andros@xxxxxxxxxx wrote:
> From: Andy Adamson <andros@xxxxxxxxxx>
>
> Prepare to embed struct pnfs_layout_tupe into layout driver private structs
> and to make layout a pointer: state flags need to be accessible before
> allocation.
>
I don't get that. A pointer inspection operation is atomic. (gone are the
days of 16-bit large/huge models where a pointer is two registers.)
So an: if (lo->pointer) is just as atomic as test_bit()
And I don't see, not here, and not in the next patch, where are these used before
the allocation. if you throw away Fred's first patch and make:
layoutcommit_needed(struct nfs_inode *nfsi)
{
- return nfsi->layout.lo_cred != NULL;
+ return nfsi->layout != NULL;
}
Then all three patches (first one thrown away) can just collapse to a single
embedded-to-pointer conversion.
Boaz
> Signed-off-by: Andy Adamson <andros@xxxxxxxxxx>
> ---
> fs/nfs/inode.c | 2 +-
> fs/nfs/pnfs.c | 16 ++++++++--------
> include/linux/nfs_fs.h | 10 +++++-----
> 3 files changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
> index 7989dea..66d7be2 100644
> --- a/fs/nfs/inode.c
> +++ b/fs/nfs/inode.c
> @@ -1364,7 +1364,6 @@ void nfs4_clear_inode(struct inode *inode)
> static void pnfs_alloc_init_inode(struct nfs_inode *nfsi)
> {
> #ifdef CONFIG_NFS_V4_1
> - nfsi->layout.pnfs_layout_state = 0;
> memset(&nfsi->layout.stateid, 0, NFS4_STATEID_SIZE);
> nfsi->layout.roc_iomode = 0;
> nfsi->layout.lo_cred = NULL;
> @@ -1420,6 +1419,7 @@ 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;
> seqlock_init(&nfsi->layout.seqlock);
> INIT_LIST_HEAD(&nfsi->layout.lo_layouts);
> INIT_LIST_HEAD(&nfsi->layout.segs);
> diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
> index bf15b5c..d05cb03 100644
> --- a/fs/nfs/pnfs.c
> +++ b/fs/nfs/pnfs.c
> @@ -951,7 +951,7 @@ get_lock_alloc_layout(struct inode *ino)
> * wait until bit is cleared if we lost this race.
> */
> res = wait_on_bit_lock(
> - &nfsi->layout.pnfs_layout_state,
> + &nfsi->pnfs_layout_state,
> NFS_INO_LAYOUT_ALLOC,
> pnfs_wait_schedule, TASK_KILLABLE);
> if (res) {
> @@ -975,8 +975,8 @@ get_lock_alloc_layout(struct inode *ino)
>
> /* release the NFS_INO_LAYOUT_ALLOC bit and wake up waiters */
> clear_bit_unlock(NFS_INO_LAYOUT_ALLOC,
> - &nfsi->layout.pnfs_layout_state);
> - wake_up_bit(&nfsi->layout.pnfs_layout_state,
> + &nfsi->pnfs_layout_state);
> + wake_up_bit(&nfsi->pnfs_layout_state,
> NFS_INO_LAYOUT_ALLOC);
> break;
> }
> @@ -1104,12 +1104,12 @@ _pnfs_update_layout(struct inode *ino,
> }
>
> /* if get layout already failed once goto out */
> - if (test_bit(lo_fail_bit(iomode), &nfsi->layout.pnfs_layout_state)) {
> + if (test_bit(lo_fail_bit(iomode), &nfsi->pnfs_layout_state)) {
> if (unlikely(nfsi->layout.pnfs_layout_suspend &&
> get_seconds() >= nfsi->layout.pnfs_layout_suspend)) {
> dprintk("%s: layout_get resumed\n", __func__);
> clear_bit(lo_fail_bit(iomode),
> - &nfsi->layout.pnfs_layout_state);
> + &nfsi->pnfs_layout_state);
> nfsi->layout.pnfs_layout_suspend = 0;
> } else
> goto out_put;
> @@ -1121,7 +1121,7 @@ _pnfs_update_layout(struct inode *ino,
> send_layoutget(ino, ctx, &arg, lsegpp, lo);
> out:
> dprintk("%s end, state 0x%lx lseg %p\n", __func__,
> - nfsi->layout.pnfs_layout_state, lseg);
> + nfsi->pnfs_layout_state, lseg);
> return;
> out_put:
> if (lsegpp)
> @@ -1226,12 +1226,12 @@ pnfs_get_layout_done(struct nfs4_pnfs_layoutget *lgp, int rpc_status)
> /* remember that get layout failed and suspend trying */
> nfsi->layout.pnfs_layout_suspend = suspend;
> set_bit(lo_fail_bit(lgp->args.lseg.iomode),
> - &nfsi->layout.pnfs_layout_state);
> + &nfsi->pnfs_layout_state);
> dprintk("%s: layout_get suspended until %ld\n",
> __func__, suspend);
> out:
> dprintk("%s end (err:%d) state 0x%lx lseg %p\n",
> - __func__, lgp->status, nfsi->layout.pnfs_layout_state, lseg);
> + __func__, lgp->status, nfsi->pnfs_layout_state, lseg);
> return;
> }
>
> diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
> index a33e86e..e216e24 100644
> --- a/include/linux/nfs_fs.h
> +++ b/include/linux/nfs_fs.h
> @@ -105,11 +105,6 @@ struct pnfs_layout_type {
> seqlock_t seqlock; /* Protects the stateid */
> nfs4_stateid stateid;
> void *ld_data; /* layout driver private data */
> - unsigned long pnfs_layout_state;
> - #define NFS_INO_RO_LAYOUT_FAILED 0 /* get ro layout failed stop trying */
> - #define NFS_INO_RW_LAYOUT_FAILED 1 /* get rw layout failed stop trying */
> - #define NFS_INO_LAYOUT_ALLOC 2 /* bit lock for layout allocation */
> - #define NFS_INO_LAYOUTCOMMIT 3 /* LAYOUTCOMMIT needed */
> time_t pnfs_layout_suspend;
> struct rpc_cred *lo_cred; /* layoutcommit credential */
> /* DH: These vars keep track of the maximum write range
> @@ -208,6 +203,11 @@ struct nfs_inode {
> #if defined(CONFIG_NFS_V4_1)
> wait_queue_head_t lo_waitq;
> 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 */
> + #define NFS_INO_LAYOUT_ALLOC 2 /* bit lock for layout allocation */
> + #define NFS_INO_LAYOUTCOMMIT 3 /* LAYOUTCOMMIT needed */
> #endif /* CONFIG_NFS_V4_1 */
> #endif /* CONFIG_NFS_V4*/
> #ifdef CONFIG_NFS_FSCACHE
--
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