Commit acee478a authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFS: Clean up the write request locking. 



Ensure that we set/clear NFS_PAGE_TAG_LOCKED when the nfs_page is hashed.

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 8b1f9ee5

fs/nfs/pagelist.c

+8 −5
Original line number Diff line number Diff line
@@ -111,12 +111,13 @@ void nfs_unlock_request(struct nfs_page *req) 
 * nfs_set_page_tag_locked - Tag a request as locked

 * @req:

 */

static int nfs_set_page_tag_locked(struct nfs_page *req)

int nfs_set_page_tag_locked(struct nfs_page *req)

{

	struct nfs_inode *nfsi = NFS_I(req->wb_context->path.dentry->d_inode);



	if (!nfs_lock_request(req))

	if (!nfs_lock_request_dontget(req))

		return 0;

	if (req->wb_page != NULL)

		radix_tree_tag_set(&nfsi->nfs_page_tree, req->wb_index, NFS_PAGE_TAG_LOCKED);

	return 1;

}
@@ -132,8 +133,9 @@ void nfs_clear_page_tag_locked(struct nfs_page *req) 
	if (req->wb_page != NULL) {

		spin_lock(&inode->i_lock);

		radix_tree_tag_clear(&nfsi->nfs_page_tree, req->wb_index, NFS_PAGE_TAG_LOCKED);

		nfs_unlock_request(req);

		spin_unlock(&inode->i_lock);

	}

	} else

		nfs_unlock_request(req);

}
@@ -421,6 +423,7 @@ int nfs_scan_list(struct nfs_inode *nfsi, 
				goto out;

			idx_start = req->wb_index + 1;

			if (nfs_set_page_tag_locked(req)) {

				kref_get(&req->wb_kref);

				nfs_list_remove_request(req);

				radix_tree_tag_clear(&nfsi->nfs_page_tree,

						req->wb_index, tag);

fs/nfs/write.c

+7 −9
Original line number Diff line number Diff line
@@ -196,7 +196,7 @@ static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page, 
	}

	/* Update file length */

	nfs_grow_file(page, offset, count);

	nfs_unlock_request(req);

	nfs_clear_page_tag_locked(req);

	return 0;

}
@@ -252,7 +252,6 @@ static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio, 
				struct page *page)

{

	struct inode *inode = page->mapping->host;

	struct nfs_inode *nfsi = NFS_I(inode);

	struct nfs_page *req;

	int ret;
@@ -263,10 +262,10 @@ static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio, 
			spin_unlock(&inode->i_lock);

			return 0;

		}

		if (nfs_lock_request_dontget(req))

		if (nfs_set_page_tag_locked(req))

			break;

		/* Note: If we hold the page lock, as is the case in nfs_writepage,

		 *	 then the call to nfs_lock_request_dontget() will always

		 *	 then the call to nfs_set_page_tag_locked() will always

		 *	 succeed provided that someone hasn't already marked the

		 *	 request as dirty (in which case we don't care).

		 */
@@ -280,7 +279,7 @@ static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio, 
	if (test_bit(PG_NEED_COMMIT, &req->wb_flags)) {

		/* This request is marked for commit */

		spin_unlock(&inode->i_lock);

		nfs_unlock_request(req);

		nfs_clear_page_tag_locked(req);

		nfs_pageio_complete(pgio);

		return 0;

	}
@@ -288,8 +287,6 @@ static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio, 
		spin_unlock(&inode->i_lock);

		BUG();

	}

	radix_tree_tag_set(&nfsi->nfs_page_tree, req->wb_index,

			NFS_PAGE_TAG_LOCKED);

	spin_unlock(&inode->i_lock);

	nfs_pageio_add_request(pgio, req);

	return 0;
@@ -381,6 +378,7 @@ static int nfs_inode_add_request(struct inode *inode, struct nfs_page *req) 
	set_page_private(req->wb_page, (unsigned long)req);

	nfsi->npages++;

	kref_get(&req->wb_kref);

	radix_tree_tag_set(&nfsi->nfs_page_tree, req->wb_index, NFS_PAGE_TAG_LOCKED);

	return 0;

}
@@ -596,7 +594,7 @@ static struct nfs_page * nfs_update_request(struct nfs_open_context* ctx, 
		spin_lock(&inode->i_lock);

		req = nfs_page_find_request_locked(page);

		if (req) {

			if (!nfs_lock_request_dontget(req)) {

			if (!nfs_set_page_tag_locked(req)) {

				int error;



				spin_unlock(&inode->i_lock);
@@ -646,7 +644,7 @@ static struct nfs_page * nfs_update_request(struct nfs_open_context* ctx, 
	    || req->wb_page != page

	    || !nfs_dirty_request(req)

	    || offset > rqend || end < req->wb_offset) {

		nfs_unlock_request(req);

		nfs_clear_page_tag_locked(req);

		return ERR_PTR(-EBUSY);

	}

include/linux/nfs_page.h

+1 −12
Original line number Diff line number Diff line
@@ -83,6 +83,7 @@ extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc); 
extern	void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);

extern  int nfs_wait_on_request(struct nfs_page *);

extern	void nfs_unlock_request(struct nfs_page *req);

extern	int nfs_set_page_tag_locked(struct nfs_page *req);

extern  void nfs_clear_page_tag_locked(struct nfs_page *req);
@@ -95,18 +96,6 @@ nfs_lock_request_dontget(struct nfs_page *req) 
	return !test_and_set_bit(PG_BUSY, &req->wb_flags);

}



/*

 * Lock the page of an asynchronous request and take a reference

 */

static inline int

nfs_lock_request(struct nfs_page *req)

{

	if (test_and_set_bit(PG_BUSY, &req->wb_flags))

		return 0;

	kref_get(&req->wb_kref);

	return 1;

}



/**

 * nfs_list_add_request - Insert a request into a list

 * @req: request