On Feb 21, 2011, at 10:49 AM, Benny Halevy wrote:
> On 2011-02-21 09:49, Fred Isaman wrote:
>> Signed-off-by: Fred Isaman <iisaman@xxxxxxxxxx>
>> ---
>> fs/nfs/pnfs.c | 25 +++++++++++++++++++++++++
>> fs/nfs/pnfs.h | 7 +++++++
>> fs/nfs/write.c | 32 ++++++++++++++++++++------------
>> 3 files changed, 52 insertions(+), 12 deletions(-)
>>
>> diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
>> index a7ea646..0ed3948d 100644
>> --- a/fs/nfs/pnfs.c
>> +++ b/fs/nfs/pnfs.c
>> @@ -876,6 +876,31 @@ pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, struct inode *inode)
>> pgio->pg_test = (ld && ld->pg_test) ? pnfs_read_pg_test : NULL;
>> }
>>
>> +static int pnfs_write_pg_test(struct nfs_pageio_descriptor *pgio,
>> + struct nfs_page *prev,
>> + struct nfs_page *req)
>> +{
>> + if (pgio->pg_count == prev->wb_bytes) {
>> + /* This is first coelesce call for a series of nfs_pages */
>> + pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
>> + prev->wb_context,
>> + IOMODE_RW);
>> + }
>> + return NFS_SERVER(pgio->pg_inode)->pnfs_curr_ld->pg_test(pgio, prev, req);
>> +}
>> +
>> +/*
>> + * rsize is already set by caller to MDS rsize.
>> + */
>
> This comment is confusing and looks out of place...
OK. I suggest we remove similar comment in the read code too.
>
>> +void
>> +pnfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, struct inode *inode)
>> +{
>> + struct pnfs_layoutdriver_type *ld;
>> +
>> + ld = NFS_SERVER(inode)->pnfs_curr_ld;
>> + pgio->pg_test = (ld && ld->pg_test) ? pnfs_write_pg_test : NULL;
>> +}
>> +
>> /*
>> * Call the appropriate parallel I/O subsystem read function.
>> */
>> diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
>> index acbb778..1d4e631 100644
>> --- a/fs/nfs/pnfs.h
>> +++ b/fs/nfs/pnfs.h
>> @@ -123,6 +123,7 @@ void unset_pnfs_layoutdriver(struct nfs_server *);
>> enum pnfs_try_status pnfs_try_to_read_data(struct nfs_read_data *,
>> const struct rpc_call_ops *);
>> void pnfs_pageio_init_read(struct nfs_pageio_descriptor *, struct inode *);
>> +void pnfs_pageio_init_write(struct nfs_pageio_descriptor *, struct inode *);
>> int pnfs_layout_process(struct nfs4_layoutget *lgp);
>> void pnfs_free_lseg_list(struct list_head *tmp_list);
>> void pnfs_destroy_layout(struct nfs_inode *);
>> @@ -235,6 +236,12 @@ pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, struct inode *ino)
>> pgio->pg_test = NULL;
>> }
>>
>> +static inline void
>> +pnfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, struct inode *ino)
>> +{
>> + pgio->pg_test = NULL;
>> +}
>> +
>> #endif /* CONFIG_NFS_V4_1 */
>>
>> #endif /* FS_NFS_PNFS_H */
>> diff --git a/fs/nfs/write.c b/fs/nfs/write.c
>> index 0df18ae..6cf5de6 100644
>> --- a/fs/nfs/write.c
>> +++ b/fs/nfs/write.c
>> @@ -919,6 +919,8 @@ static int nfs_flush_multi(struct inode *inode, struct list_head *head, unsigned
>> } while (nbytes != 0);
>> atomic_set(&req->wb_complete, requests);
>>
>> + /* We know lseg==NULL */
>
> Then maybe BUG_ON or WARN_ON(lseg != NULL)?
OK.
>
>> + lseg = pnfs_update_layout(inode, req->wb_context, IOMODE_RW);
>> ClearPageError(page);
>> offset = 0;
>> nbytes = count;
>> @@ -940,6 +942,7 @@ static int nfs_flush_multi(struct inode *inode, struct list_head *head, unsigned
>> nbytes -= wsize;
>> } while (nbytes != 0);
>>
>> + put_lseg(lseg);
>> return ret;
>>
>> out_bad:
>> @@ -965,11 +968,18 @@ static int nfs_flush_one(struct inode *inode, struct list_head *head, unsigned i
>> struct nfs_page *req;
>> struct page **pages;
>> struct nfs_write_data *data;
>> + int ret;
>>
>> data = nfs_writedata_alloc(npages);
>> - if (!data)
>> - goto out_bad;
>> -
>> + if (!data) {
>> + while (!list_empty(head)) {
>> + req = nfs_list_entry(head->next);
>
> nit: it'd be cleaner to define a nfs_list_first_entry helper in nfs_page.h
> rather than using a combination of list helpers and open code (head->next).
I would think that would be a separate patch. As this is just a simple move of pre-existing code,
it is easier to see what is happening if I leave the copied code the same.
>
>> + nfs_list_remove_request(req);
>> + nfs_redirty_request(req);
>> + }
>> + ret = -ENOMEM;
>> + goto out;
>> + }
>> pages = data->pagevec;
>> while (!list_empty(head)) {
>> req = nfs_list_entry(head->next);
>> @@ -979,16 +989,14 @@ static int nfs_flush_one(struct inode *inode, struct list_head *head, unsigned i
>> *pages++ = req->wb_page;
>> }
>> req = nfs_list_entry(data->pages.next);
>> + if ((!lseg) && list_is_singular(&data->pages))
>> + lseg = pnfs_update_layout(inode, req->wb_context, IOMODE_RW);
>>
>> /* Set up the argument struct */
>> - return nfs_write_rpcsetup(req, data, &nfs_write_full_ops, count, 0, lseg, how);
>> - out_bad:
>> - while (!list_empty(head)) {
>> - req = nfs_list_entry(head->next);
>> - nfs_list_remove_request(req);
>> - nfs_redirty_request(req);
>> - }
>> - return -ENOMEM;
>> + ret = nfs_write_rpcsetup(req, data, &nfs_write_full_ops, count, 0, lseg, how);
>> +out:
>> + put_lseg(lseg);
>
> Shouldn't you do that only if lseg was updated above?
>
No, this is the put matching the get done in the pg_test function. I'll comment that.
Fred
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