Commit c917cfaf authored by Trond Myklebust's avatar Trond Myklebust Committed by Anna Schumaker
Browse files

NFS: Fix up NFS I/O subrequest creation 



We require all NFS I/O subrequests to duplicate the lock context as well
as the open context.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 6fbda89b

fs/nfs/pagelist.c

+55 −38
Original line number Diff line number Diff line
@@ -295,25 +295,13 @@ nfs_page_group_destroy(struct kref *kref) 
		nfs_release_request(head);

}



/**

 * nfs_create_request - Create an NFS read/write request.

 * @ctx: open context to use

 * @page: page to write

 * @last: last nfs request created for this page group or NULL if head

 * @offset: starting offset within the page for the write

 * @count: number of bytes to read/write

 *

 * The page must be locked by the caller. This makes sure we never

 * create two different requests for the same page.

 * User should ensure it is safe to sleep in this function.

 */

struct nfs_page *

nfs_create_request(struct nfs_open_context *ctx, struct page *page,

		   struct nfs_page *last, unsigned int offset,

		   unsigned int count)

static struct nfs_page *

__nfs_create_request(struct nfs_lock_context *l_ctx, struct page *page,

		   struct nfs_page *last, unsigned int pgbase,

		   unsigned int offset, unsigned int count)

{

	struct nfs_page		*req;

	struct nfs_lock_context *l_ctx;

	struct nfs_open_context *ctx = l_ctx->open_context;



	if (test_bit(NFS_CONTEXT_BAD, &ctx->flags))

		return ERR_PTR(-EBADF);
@@ -322,13 +310,8 @@ nfs_create_request(struct nfs_open_context *ctx, struct page *page, 
	if (req == NULL)

		return ERR_PTR(-ENOMEM);



	/* get lock context early so we can deal with alloc failures */

	l_ctx = nfs_get_lock_context(ctx);

	if (IS_ERR(l_ctx)) {

		nfs_page_free(req);

		return ERR_CAST(l_ctx);

	}

	req->wb_lock_context = l_ctx;

	refcount_inc(&l_ctx->count);

	atomic_inc(&l_ctx->io_count);



	/* Initialize the request struct. Initially, we assume a
@@ -340,7 +323,7 @@ nfs_create_request(struct nfs_open_context *ctx, struct page *page, 
		get_page(page);

	}

	req->wb_offset  = offset;

	req->wb_pgbase	= offset;

	req->wb_pgbase	= pgbase;

	req->wb_bytes   = count;

	req->wb_context = get_nfs_open_context(ctx);

	kref_init(&req->wb_kref);
@@ -348,6 +331,49 @@ nfs_create_request(struct nfs_open_context *ctx, struct page *page, 
	return req;

}



/**

 * nfs_create_request - Create an NFS read/write request.

 * @ctx: open context to use

 * @page: page to write

 * @last: last nfs request created for this page group or NULL if head

 * @offset: starting offset within the page for the write

 * @count: number of bytes to read/write

 *

 * The page must be locked by the caller. This makes sure we never

 * create two different requests for the same page.

 * User should ensure it is safe to sleep in this function.

 */

struct nfs_page *

nfs_create_request(struct nfs_open_context *ctx, struct page *page,

		   struct nfs_page *last, unsigned int offset,

		   unsigned int count)

{

	struct nfs_lock_context *l_ctx = nfs_get_lock_context(ctx);

	struct nfs_page *ret;



	if (IS_ERR(l_ctx))

		return ERR_CAST(l_ctx);

	ret = __nfs_create_request(l_ctx, page, last, offset, offset, count);

	nfs_put_lock_context(l_ctx);

	return ret;

}



static struct nfs_page *

nfs_create_subreq(struct nfs_page *req, struct nfs_page *last,

		  unsigned int pgbase, unsigned int offset,

		  unsigned int count)

{

	struct nfs_page *ret;



	ret = __nfs_create_request(req->wb_lock_context, req->wb_page, last,

			pgbase, offset, count);

	if (!IS_ERR(ret)) {

		nfs_lock_request(ret);

		ret->wb_index = req->wb_index;

	}

	return ret;

}



/**

 * nfs_unlock_request - Unlock request and wake up sleepers.

 * @req: pointer to request
@@ -1049,14 +1075,10 @@ static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, 
		pgbase += subreq->wb_bytes;



		if (bytes_left) {

			subreq = nfs_create_request(req->wb_context,

					req->wb_page,

					subreq, pgbase, bytes_left);

			subreq = nfs_create_subreq(req, subreq, pgbase,

					offset, bytes_left);

			if (IS_ERR(subreq))

				goto err_ptr;

			nfs_lock_request(subreq);

			subreq->wb_offset  = offset;

			subreq->wb_index = req->wb_index;

		}

	} while (bytes_left > 0);
@@ -1158,19 +1180,14 @@ int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, 
			     lastreq = lastreq->wb_this_page)

				;



			dupreq = nfs_create_request(req->wb_context,

					req->wb_page, lastreq, pgbase, bytes);

			dupreq = nfs_create_subreq(req, lastreq,

					pgbase, offset, bytes);



			if (IS_ERR(dupreq)) {

			nfs_page_group_unlock(req);

			if (IS_ERR(dupreq)) {

				desc->pg_error = PTR_ERR(dupreq);

				goto out_failed;

			}



			nfs_lock_request(dupreq);

			nfs_page_group_unlock(req);

			dupreq->wb_offset = offset;

			dupreq->wb_index = req->wb_index;

		} else

			dupreq = req;