Commit 919e3bd9 authored by Trond Myklebust's avatar Trond Myklebust Committed by Anna Schumaker
Browse files

NFS: Ensure we commit after writeback is complete 



If the page cache is being flushed, then we want to ensure that we
do start a commit once the pages are done being flushed.
If we just wait until all I/O is done to that file, we can end up
livelocking until the balance_dirty_pages() mechanism puts its
foot down and forces I/O to stop.
So instead we do more or less the same thing that O_DIRECT does,
and set up a counter to tell us when the flush is done,

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent b5973a8c

fs/nfs/pagelist.c

+3 −0
Original line number Diff line number Diff line
@@ -50,6 +50,7 @@ void nfs_pgheader_init(struct nfs_pageio_descriptor *desc, 
	hdr->cred = hdr->req->wb_context->cred;

	hdr->io_start = req_offset(hdr->req);

	hdr->good_bytes = mirror->pg_count;

	hdr->io_completion = desc->pg_io_completion;

	hdr->dreq = desc->pg_dreq;

	hdr->release = release;

	hdr->completion_ops = desc->pg_completion_ops;
@@ -709,6 +710,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc, 
	desc->pg_ioflags = io_flags;

	desc->pg_error = 0;

	desc->pg_lseg = NULL;

	desc->pg_io_completion = NULL;

	desc->pg_dreq = NULL;

	desc->pg_bsize = bsize;
@@ -1231,6 +1233,7 @@ int nfs_pageio_resend(struct nfs_pageio_descriptor *desc, 
{

	LIST_HEAD(failed);



	desc->pg_io_completion = hdr->io_completion;

	desc->pg_dreq = hdr->dreq;

	while (!list_empty(&hdr->pages)) {

		struct nfs_page *req = nfs_list_entry(hdr->pages.next);

fs/nfs/write.c

+57 −0
Original line number Diff line number Diff line
@@ -40,6 +40,12 @@ 
#define MIN_POOL_WRITE		(32)

#define MIN_POOL_COMMIT		(4)



struct nfs_io_completion {

	void (*complete)(void *data);

	void *data;

	struct kref refcount;

};



/*

 * Local function declarations

 */
@@ -108,6 +114,39 @@ static void nfs_writehdr_free(struct nfs_pgio_header *hdr) 
	mempool_free(hdr, nfs_wdata_mempool);

}



static struct nfs_io_completion *nfs_io_completion_alloc(gfp_t gfp_flags)

{

	return kmalloc(sizeof(struct nfs_io_completion), gfp_flags);

}



static void nfs_io_completion_init(struct nfs_io_completion *ioc,

		void (*complete)(void *), void *data)

{

	ioc->complete = complete;

	ioc->data = data;

	kref_init(&ioc->refcount);

}



static void nfs_io_completion_release(struct kref *kref)

{

	struct nfs_io_completion *ioc = container_of(kref,

			struct nfs_io_completion, refcount);

	ioc->complete(ioc->data);

	kfree(ioc);

}



static void nfs_io_completion_get(struct nfs_io_completion *ioc)

{

	if (ioc != NULL)

		kref_get(&ioc->refcount);

}



static void nfs_io_completion_put(struct nfs_io_completion *ioc)

{

	if (ioc != NULL)

		kref_put(&ioc->refcount, nfs_io_completion_release);

}



static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error)

{

	ctx->error = error;
@@ -681,18 +720,29 @@ static int nfs_writepages_callback(struct page *page, struct writeback_control * 
	return ret;

}



static void nfs_io_completion_commit(void *inode)

{

	nfs_commit_inode(inode, 0);

}



int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)

{

	struct inode *inode = mapping->host;

	struct nfs_pageio_descriptor pgio;

	struct nfs_io_completion *ioc = nfs_io_completion_alloc(GFP_NOFS);

	int err;



	nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);



	if (ioc)

		nfs_io_completion_init(ioc, nfs_io_completion_commit, inode);



	nfs_pageio_init_write(&pgio, inode, wb_priority(wbc), false,

				&nfs_async_write_completion_ops);

	pgio.pg_io_completion = ioc;

	err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio);

	nfs_pageio_complete(&pgio);

	nfs_io_completion_put(ioc);



	if (err < 0)

		goto out_err;
@@ -940,6 +990,11 @@ int nfs_write_need_commit(struct nfs_pgio_header *hdr) 
	return hdr->verf.committed != NFS_FILE_SYNC;

}



static void nfs_async_write_init(struct nfs_pgio_header *hdr)

{

	nfs_io_completion_get(hdr->io_completion);

}



static void nfs_write_completion(struct nfs_pgio_header *hdr)

{

	struct nfs_commit_info cinfo;
@@ -973,6 +1028,7 @@ next: 
		nfs_release_request(req);

	}

out:

	nfs_io_completion_put(hdr->io_completion);

	hdr->release(hdr);

}
@@ -1378,6 +1434,7 @@ static void nfs_async_write_reschedule_io(struct nfs_pgio_header *hdr) 
}



static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = {

	.init_hdr = nfs_async_write_init,

	.error_cleanup = nfs_async_write_error,

	.completion = nfs_write_completion,

	.reschedule_io = nfs_async_write_reschedule_io,

include/linux/nfs_page.h

+1 −0
Original line number Diff line number Diff line
@@ -93,6 +93,7 @@ struct nfs_pageio_descriptor { 
	const struct rpc_call_ops *pg_rpc_callops;

	const struct nfs_pgio_completion_ops *pg_completion_ops;

	struct pnfs_layout_segment *pg_lseg;

	struct nfs_io_completion *pg_io_completion;

	struct nfs_direct_req	*pg_dreq;

	unsigned int		pg_bsize;	/* default bsize for mirrors */

include/linux/nfs_xdr.h

+2 −0
Original line number Diff line number Diff line
@@ -1422,6 +1422,7 @@ enum { 
	NFS_IOHDR_STAT,

};



struct nfs_io_completion;

struct nfs_pgio_header {

	struct inode		*inode;

	struct rpc_cred		*cred;
@@ -1435,6 +1436,7 @@ struct nfs_pgio_header { 
	void (*release) (struct nfs_pgio_header *hdr);

	const struct nfs_pgio_completion_ops *completion_ops;

	const struct nfs_rw_ops	*rw_ops;

	struct nfs_io_completion *io_completion;

	struct nfs_direct_req	*dreq;

	spinlock_t		lock;

	/* fields protected by lock */

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