Re: [PATCH 15/18 v2] pnfs: support multiple verfs per direct req

[Anna Schumaker <schumaker.anna@gmail.com>]

On 04/25/2014 11:38 AM, Weston Andros Adamson wrote:
> On Apr 25, 2014, at 11:12 AM, Weston Andros Adamson <dros@primarydata.com> wrote:
>
>> On Apr 25, 2014, at 10:15 AM, Anna Schumaker <schumaker.anna@gmail.com> wrote:
>>
>>> On 04/24/2014 02:15 PM, Weston Andros Adamson wrote:
>>>> Support direct requests that span multiple pnfs data servers by
>>>> comparing nfs_pgio_header->verf to a cached verf in pnfs_commit_bucket.
>>>> Continue to use dreq->verf if the MDS is used / non-pNFS.
>>>>
>>>> Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
>>>> ---
>>>> fs/nfs/direct.c         | 98 ++++++++++++++++++++++++++++++++++++++++++++++---
>>>> fs/nfs/nfs4filelayout.c |  6 +++
>>>> include/linux/nfs.h     |  5 ++-
>>>> include/linux/nfs_xdr.h |  2 +
>>>> 4 files changed, 105 insertions(+), 6 deletions(-)
>>>>
>>>> diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
>>>> index 2c0e08f..9349933 100644
>>>> --- a/fs/nfs/direct.c
>>>> +++ b/fs/nfs/direct.c
>>>> @@ -108,6 +108,93 @@ static inline int put_dreq(struct nfs_direct_req *dreq)
>>>> 	return atomic_dec_and_test(&dreq->io_count);
>>>> }
>>>>
>>>> +/*
>>>> + * nfs_direct_select_verf - select the right verifier
>>>> + * @dreq - direct request possibly spanning multiple servers
>>>> + * @ds_clp - nfs_client of data server or NULL if MDS / non-pnfs
>>>> + * @ds_idx - index of data server in data server list, only valid if ds_clp set
>>>> + *
>>>> + * returns the correct verifier to use given the role of the server
>>>> + */
>>>> +static struct nfs_writeverf *
>>>> +nfs_direct_select_verf(struct nfs_direct_req *dreq,
>>>> +		       struct nfs_client *ds_clp,
>>>> +		       int ds_idx)
>>>> +{
>>>> +	struct nfs_writeverf *verfp = &dreq->verf;
>>>> +
>>>> +	if (ds_clp) {
>>>> +		/* pNFS is in use, use the DS verf */
>>>> +		if (ds_idx >= 0 && ds_idx < dreq->ds_cinfo.nbuckets)
>>> The struct pnfs_ds_commit_info is empty if CONFIG_NFS_V4_1=n, so this won't compile.
>>>
>>> Anna
>> Good catch, I�ll iterate through the patchset and test with v4.1 disabled.
>>
>> Time to add some #ifdefs
>>
>> -dros
> That was the only problem I found with 4.1 disabled.
>
> Fixed and pushed.

Thanks! I'm now getting a "defined but not used" error if just v2 is enabled:

NFS_V4_2=n PNFS_OBJLAYOUT=n PNFS_BLOCK=n PNFS_FILE_LAYOUT=n NFS_V4_1=n NFS_V4=n NFS_V3=n NFS_V2=y

fs/nfs/direct.c:189:12: error: ‘nfs_direct_cmp_commit_data_verf’ defined but not used [-Werror=unused-function]
static int nfs_direct_cmp_commit_data_verf(struct nfs_direct_req *dreq,

Anna

>
> -dros
>
>>>> +			verfp = &dreq->ds_cinfo.buckets[ds_idx].direct_verf;
>>>> +		else
>>>> +			WARN_ON_ONCE(1);
>>>> +	}
>>>> +	return verfp;
>>>> +}
>>>> +
>>>> +
>>>> +/*
>>>> + * nfs_direct_set_hdr_verf - set the write/commit verifier
>>>> + * @dreq - direct request possibly spanning multiple servers
>>>> + * @hdr - pageio header to validate against previously seen verfs
>>>> + *
>>>> + * Set the server's (MDS or DS) "seen" verifier
>>>> + */
>>>> +static void nfs_direct_set_hdr_verf(struct nfs_direct_req *dreq,
>>>> +				    struct nfs_pgio_header *hdr)
>>>> +{
>>>> +	struct nfs_writeverf *verfp;
>>>> +
>>>> +	verfp = nfs_direct_select_verf(dreq, hdr->data->ds_clp,
>>>> +				      hdr->data->ds_idx);
>>>> +	WARN_ON_ONCE(verfp->committed >= 0);
>>>> +	memcpy(verfp, &hdr->verf, sizeof(struct nfs_writeverf));
>>>> +	WARN_ON_ONCE(verfp->committed < 0);
>>>> +}
>>>> +
>>>> +/*
>>>> + * nfs_direct_cmp_hdr_verf - compare verifier for pgio header
>>>> + * @dreq - direct request possibly spanning multiple servers
>>>> + * @hdr - pageio header to validate against previously seen verf
>>>> + *
>>>> + * set the server's "seen" verf if not initialized.
>>>> + * returns result of comparison between @hdr->verf and the "seen"
>>>> + * verf of the server used by @hdr (DS or MDS)
>>>> + */
>>>> +static int nfs_direct_set_or_cmp_hdr_verf(struct nfs_direct_req *dreq,
>>>> +					  struct nfs_pgio_header *hdr)
>>>> +{
>>>> +	struct nfs_writeverf *verfp;
>>>> +
>>>> +	verfp = nfs_direct_select_verf(dreq, hdr->data->ds_clp,
>>>> +					 hdr->data->ds_idx);
>>>> +	if (verfp->committed < 0) {
>>>> +		nfs_direct_set_hdr_verf(dreq, hdr);
>>>> +		return 0;
>>>> +	}
>>>> +	return memcmp(verfp, &hdr->verf, sizeof(struct nfs_writeverf));
>>>> +}
>>>> +
>>>> +/*
>>>> + * nfs_direct_cmp_commit_data_verf - compare verifier for commit data
>>>> + * @dreq - direct request possibly spanning multiple servers
>>>> + * @data - commit data to validate against previously seen verf
>>>> + *
>>>> + * returns result of comparison between @data->verf and the verf of
>>>> + * the server used by @data (DS or MDS)
>>>> + */
>>>> +static int nfs_direct_cmp_commit_data_verf(struct nfs_direct_req *dreq,
>>>> +					   struct nfs_commit_data *data)
>>>> +{
>>>> +	struct nfs_writeverf *verfp;
>>>> +
>>>> +	verfp = nfs_direct_select_verf(dreq, data->ds_clp,
>>>> +					 data->ds_commit_index);
>>>> +	WARN_ON_ONCE(verfp->committed < 0);
>>>> +	return memcmp(verfp, &data->verf, sizeof(struct nfs_writeverf));
>>>> +}
>>>> +
>>>> /**
>>>> * nfs_direct_IO - NFS address space operation for direct I/O
>>>> * @rw: direction (read or write)
>>>> @@ -168,6 +255,7 @@ static inline struct nfs_direct_req *nfs_direct_req_alloc(void)
>>>> 	kref_get(&dreq->kref);
>>>> 	init_completion(&dreq->completion);
>>>> 	INIT_LIST_HEAD(&dreq->mds_cinfo.list);
>>>> +	dreq->verf.committed = NFS_INVALID_STABLE_HOW;	/* not set yet */
>>>> 	INIT_WORK(&dreq->work, nfs_direct_write_schedule_work);
>>>> 	spin_lock_init(&dreq->lock);
>>>>
>>>> @@ -602,7 +690,7 @@ static void nfs_direct_commit_complete(struct nfs_commit_data *data)
>>>> 		dprintk("NFS: %5u commit failed with error %d.\n",
>>>> 			data->task.tk_pid, status);
>>>> 		dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
>>>> -	} else if (memcmp(&dreq->verf, &data->verf, sizeof(data->verf))) {
>>>> +	} else if (nfs_direct_cmp_commit_data_verf(dreq, data)) {
>>>> 		dprintk("NFS: %5u commit verify failed\n", data->task.tk_pid);
>>>> 		dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
>>>> 	}
>>>> @@ -811,13 +899,13 @@ static void nfs_direct_write_completion(struct nfs_pgio_header *hdr)
>>>> 			if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES)
>>>> 				bit = NFS_IOHDR_NEED_RESCHED;
>>>> 			else if (dreq->flags == 0) {
>>>> -				memcpy(&dreq->verf, &hdr->verf,
>>>> -				       sizeof(dreq->verf));
>>>> +				nfs_direct_set_hdr_verf(dreq, hdr);
>>>> 				bit = NFS_IOHDR_NEED_COMMIT;
>>>> 				dreq->flags = NFS_ODIRECT_DO_COMMIT;
>>>> 			} else if (dreq->flags == NFS_ODIRECT_DO_COMMIT) {
>>>> -				if (memcmp(&dreq->verf, &hdr->verf, sizeof(dreq->verf))) {
>>>> -					dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
>>>> +				if (nfs_direct_set_or_cmp_hdr_verf(dreq, hdr)) {
>>>> +					dreq->flags =
>>>> +						NFS_ODIRECT_RESCHED_WRITES;
>>>> 					bit = NFS_IOHDR_NEED_RESCHED;
>>>> 				} else
>>>> 					bit = NFS_IOHDR_NEED_COMMIT;
>>>> diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
>>>> index 7a665e0..0ebc521 100644
>>>> --- a/fs/nfs/nfs4filelayout.c
>>>> +++ b/fs/nfs/nfs4filelayout.c
>>>> @@ -560,6 +560,7 @@ filelayout_read_pagelist(struct nfs_pgio_data *data)
>>>> 	/* No multipath support. Use first DS */
>>>> 	atomic_inc(&ds->ds_clp->cl_count);
>>>> 	data->ds_clp = ds->ds_clp;
>>>> +	data->ds_idx = idx;
>>>> 	fh = nfs4_fl_select_ds_fh(lseg, j);
>>>> 	if (fh)
>>>> 		data->args.fh = fh;
>>>> @@ -603,6 +604,7 @@ filelayout_write_pagelist(struct nfs_pgio_data *data, int sync)
>>>> 	data->pgio_done_cb = filelayout_write_done_cb;
>>>> 	atomic_inc(&ds->ds_clp->cl_count);
>>>> 	data->ds_clp = ds->ds_clp;
>>>> +	data->ds_idx = idx;
>>>> 	fh = nfs4_fl_select_ds_fh(lseg, j);
>>>> 	if (fh)
>>>> 		data->args.fh = fh;
>>>> @@ -875,6 +877,8 @@ filelayout_alloc_commit_info(struct pnfs_layout_segment *lseg,
>>>> 	for (i = 0; i < size; i++) {
>>>> 		INIT_LIST_HEAD(&buckets[i].written);
>>>> 		INIT_LIST_HEAD(&buckets[i].committing);
>>>> +		/* mark direct verifier as unset */
>>>> +		buckets[i].direct_verf.committed = NFS_INVALID_STABLE_HOW;
>>>> 	}
>>>>
>>>> 	spin_lock(cinfo->lock);
>>>> @@ -885,6 +889,8 @@ filelayout_alloc_commit_info(struct pnfs_layout_segment *lseg,
>>>> 			    &buckets[i].written);
>>>> 		list_splice(&cinfo->ds->buckets[i].committing,
>>>> 			    &buckets[i].committing);
>>>> +		buckets[i].direct_verf.committed =
>>>> +			cinfo->ds->buckets[i].direct_verf.committed;
>>>> 		buckets[i].wlseg = cinfo->ds->buckets[i].wlseg;
>>>> 		buckets[i].clseg = cinfo->ds->buckets[i].clseg;
>>>> 	}
>>>> diff --git a/include/linux/nfs.h b/include/linux/nfs.h
>>>> index 3e794c1..610af51 100644
>>>> --- a/include/linux/nfs.h
>>>> +++ b/include/linux/nfs.h
>>>> @@ -46,6 +46,9 @@ static inline void nfs_copy_fh(struct nfs_fh *target, const struct nfs_fh *sourc
>>>> enum nfs3_stable_how {
>>>> 	NFS_UNSTABLE = 0,
>>>> 	NFS_DATA_SYNC = 1,
>>>> -	NFS_FILE_SYNC = 2
>>>> +	NFS_FILE_SYNC = 2,
>>>> +
>>>> +	/* used by direct.c to mark verf as invalid */
>>>> +	NFS_INVALID_STABLE_HOW = -1
>>>> };
>>>> #endif /* _LINUX_NFS_H */
>>>> diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
>>>> index 29828c7..bb9fb88 100644
>>>> --- a/include/linux/nfs_xdr.h
>>>> +++ b/include/linux/nfs_xdr.h
>>>> @@ -1111,6 +1111,7 @@ struct pnfs_commit_bucket {
>>>> 	struct list_head committing;
>>>> 	struct pnfs_layout_segment *wlseg;
>>>> 	struct pnfs_layout_segment *clseg;
>>>> +	struct nfs_writeverf direct_verf;
>>>> };
>>>>
>>>> struct pnfs_ds_commit_info {
>>>> @@ -1294,6 +1295,7 @@ struct nfs_pgio_data {
>>>> 	__u64			mds_offset;	/* Filelayout dense stripe */
>>>> 	struct nfs_page_array	pages;
>>>> 	struct nfs_client	*ds_clp;	/* pNFS data server */
>>>> +	int			ds_idx;		/* ds index if ds_clp is set */
>>>> };
>>>>
>>>> struct nfs_rw_header {