Commit 587142f8 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFS: Replace NFS_I(inode)->req_lock with inode->i_lock 



There is no justification for keeping a special spinlock for the exclusive
use of the NFS writeback code.

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 4e56e082

fs/nfs/inode.c

+0 −1
Original line number Diff line number Diff line
@@ -1154,7 +1154,6 @@ static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flag 
	struct nfs_inode *nfsi = (struct nfs_inode *) foo;



	inode_init_once(&nfsi->vfs_inode);

	spin_lock_init(&nfsi->req_lock);

	INIT_LIST_HEAD(&nfsi->open_files);

	INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);

	INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);

fs/nfs/pagelist.c

+6 −5
Original line number Diff line number Diff line
@@ -126,12 +126,13 @@ static int nfs_set_page_tag_locked(struct nfs_page *req) 
 */

void nfs_clear_page_tag_locked(struct nfs_page *req)

{

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

	struct inode *inode = req->wb_context->path.dentry->d_inode;

	struct nfs_inode *nfsi = NFS_I(inode);



	if (req->wb_page != NULL) {

		spin_lock(&nfsi->req_lock);

		spin_lock(&inode->i_lock);

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

		spin_unlock(&nfsi->req_lock);

		spin_unlock(&inode->i_lock);

	}

	nfs_unlock_request(req);

}
@@ -390,7 +391,7 @@ void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index) 
 * If the number of requests is set to 0, the entire address_space

 * starting at index idx_start, is scanned.

 * The requests are *not* checked to ensure that they form a contiguous set.

 * You must be holding the inode's req_lock when calling this function

 * You must be holding the inode's i_lock when calling this function

 */

int nfs_scan_list(struct nfs_inode *nfsi,

		struct list_head *dst, pgoff_t idx_start,
@@ -430,7 +431,7 @@ int nfs_scan_list(struct nfs_inode *nfsi, 
			}

		}

		/* for latency reduction */

		cond_resched_lock(&nfsi->req_lock);

		cond_resched_lock(&nfsi->vfs_inode.i_lock);

	}

out:

	return res;

fs/nfs/write.c

+40 −44
Original line number Diff line number Diff line
@@ -124,12 +124,12 @@ static struct nfs_page *nfs_page_find_request_locked(struct page *page) 


static struct nfs_page *nfs_page_find_request(struct page *page)

{

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

	struct nfs_page *req = NULL;

	spinlock_t *req_lock = &NFS_I(page->mapping->host)->req_lock;



	spin_lock(req_lock);

	spin_lock(&inode->i_lock);

	req = nfs_page_find_request_locked(page);

	spin_unlock(req_lock);

	spin_unlock(&inode->i_lock);

	return req;

}
@@ -251,16 +251,16 @@ static void nfs_end_page_writeback(struct page *page) 
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;

	struct nfs_inode *nfsi = NFS_I(page->mapping->host);

	spinlock_t *req_lock = &nfsi->req_lock;

	int ret;



	spin_lock(req_lock);

	spin_lock(&inode->i_lock);

	for(;;) {

		req = nfs_page_find_request_locked(page);

		if (req == NULL) {

			spin_unlock(req_lock);

			spin_unlock(&inode->i_lock);

			return 1;

		}

		if (nfs_lock_request_dontget(req))
@@ -270,28 +270,28 @@ static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio, 
		 *	 succeed provided that someone hasn't already marked the

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

		 */

		spin_unlock(req_lock);

		spin_unlock(&inode->i_lock);

		ret = nfs_wait_on_request(req);

		nfs_release_request(req);

		if (ret != 0)

			return ret;

		spin_lock(req_lock);

		spin_lock(&inode->i_lock);

	}

	if (test_bit(PG_NEED_COMMIT, &req->wb_flags)) {

		/* This request is marked for commit */

		spin_unlock(req_lock);

		spin_unlock(&inode->i_lock);

		nfs_unlock_request(req);

		nfs_pageio_complete(pgio);

		return 1;

	}

	if (nfs_set_page_writeback(page) != 0) {

		spin_unlock(req_lock);

		spin_unlock(&inode->i_lock);

		BUG();

	}

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

			NFS_PAGE_TAG_LOCKED);

	ret = test_bit(PG_NEED_FLUSH, &req->wb_flags);

	spin_unlock(req_lock);

	spin_unlock(&inode->i_lock);

	nfs_pageio_add_request(pgio, req);

	return ret;

}
@@ -412,7 +412,7 @@ static void nfs_inode_remove_request(struct nfs_page *req) 


	BUG_ON (!NFS_WBACK_BUSY(req));



	spin_lock(&nfsi->req_lock);

	spin_lock(&inode->i_lock);

	set_page_private(req->wb_page, 0);

	ClearPagePrivate(req->wb_page);

	radix_tree_delete(&nfsi->nfs_page_tree, req->wb_index);
@@ -420,11 +420,11 @@ static void nfs_inode_remove_request(struct nfs_page *req) 
		__set_page_dirty_nobuffers(req->wb_page);

	nfsi->npages--;

	if (!nfsi->npages) {

		spin_unlock(&nfsi->req_lock);

		spin_unlock(&inode->i_lock);

		nfs_end_data_update(inode);

		iput(inode);

	} else

		spin_unlock(&nfsi->req_lock);

		spin_unlock(&inode->i_lock);

	nfs_clear_request(req);

	nfs_release_request(req);

}
@@ -458,13 +458,13 @@ nfs_mark_request_commit(struct nfs_page *req) 
	struct inode *inode = req->wb_context->path.dentry->d_inode;

	struct nfs_inode *nfsi = NFS_I(inode);



	spin_lock(&nfsi->req_lock);

	spin_lock(&inode->i_lock);

	nfsi->ncommit++;

	set_bit(PG_NEED_COMMIT, &(req)->wb_flags);

	radix_tree_tag_set(&nfsi->nfs_page_tree,

			req->wb_index,

			NFS_PAGE_TAG_COMMIT);

	spin_unlock(&nfsi->req_lock);

	spin_unlock(&inode->i_lock);

	inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);

	__mark_inode_dirty(inode, I_DIRTY_DATASYNC);

}
@@ -534,10 +534,10 @@ static int nfs_wait_on_requests_locked(struct inode *inode, pgoff_t idx_start, u 
		BUG_ON(!NFS_WBACK_BUSY(req));



		kref_get(&req->wb_kref);

		spin_unlock(&nfsi->req_lock);

		spin_unlock(&inode->i_lock);

		error = nfs_wait_on_request(req);

		nfs_release_request(req);

		spin_lock(&nfsi->req_lock);

		spin_lock(&inode->i_lock);

		if (error < 0)

			return error;

		res++;
@@ -602,7 +602,6 @@ static struct nfs_page * nfs_update_request(struct nfs_open_context* ctx, 
{

	struct address_space *mapping = page->mapping;

	struct inode *inode = mapping->host;

	struct nfs_inode *nfsi = NFS_I(inode);

	struct nfs_page		*req, *new = NULL;

	pgoff_t		rqend, end;
@@ -612,13 +611,13 @@ static struct nfs_page * nfs_update_request(struct nfs_open_context* ctx, 
		/* Loop over all inode entries and see if we find

		 * A request for the page we wish to update

		 */

		spin_lock(&nfsi->req_lock);

		spin_lock(&inode->i_lock);

		req = nfs_page_find_request_locked(page);

		if (req) {

			if (!nfs_lock_request_dontget(req)) {

				int error;



				spin_unlock(&nfsi->req_lock);

				spin_unlock(&inode->i_lock);

				error = nfs_wait_on_request(req);

				nfs_release_request(req);

				if (error < 0) {
@@ -628,7 +627,7 @@ static struct nfs_page * nfs_update_request(struct nfs_open_context* ctx, 
				}

				continue;

			}

			spin_unlock(&nfsi->req_lock);

			spin_unlock(&inode->i_lock);

			if (new)

				nfs_release_request(new);

			break;
@@ -639,14 +638,14 @@ static struct nfs_page * nfs_update_request(struct nfs_open_context* ctx, 
			nfs_lock_request_dontget(new);

			error = nfs_inode_add_request(inode, new);

			if (error) {

				spin_unlock(&nfsi->req_lock);

				spin_unlock(&inode->i_lock);

				nfs_unlock_request(new);

				return ERR_PTR(error);

			}

			spin_unlock(&nfsi->req_lock);

			spin_unlock(&inode->i_lock);

			return new;

		}

		spin_unlock(&nfsi->req_lock);

		spin_unlock(&inode->i_lock);



		new = nfs_create_request(ctx, inode, page, offset, bytes);

		if (IS_ERR(new))
@@ -974,9 +973,9 @@ static void nfs_writeback_done_partial(struct rpc_task *task, void *calldata) 
	}



	if (nfs_write_need_commit(data)) {

		spinlock_t *req_lock = &NFS_I(page->mapping->host)->req_lock;

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



		spin_lock(req_lock);

		spin_lock(&inode->i_lock);

		if (test_bit(PG_NEED_RESCHED, &req->wb_flags)) {

			/* Do nothing we need to resend the writes */

		} else if (!test_and_set_bit(PG_NEED_COMMIT, &req->wb_flags)) {
@@ -987,7 +986,7 @@ static void nfs_writeback_done_partial(struct rpc_task *task, void *calldata) 
			clear_bit(PG_NEED_COMMIT, &req->wb_flags);

			dprintk(" server reboot detected\n");

		}

		spin_unlock(req_lock);

		spin_unlock(&inode->i_lock);

	} else

		dprintk(" OK\n");
@@ -1277,13 +1276,12 @@ static const struct rpc_call_ops nfs_commit_ops = { 


int nfs_commit_inode(struct inode *inode, int how)

{

	struct nfs_inode *nfsi = NFS_I(inode);

	LIST_HEAD(head);

	int res;



	spin_lock(&nfsi->req_lock);

	spin_lock(&inode->i_lock);

	res = nfs_scan_commit(inode, &head, 0, 0);

	spin_unlock(&nfsi->req_lock);

	spin_unlock(&inode->i_lock);

	if (res) {

		int error = nfs_commit_list(inode, &head, how);

		if (error < 0)
@@ -1301,7 +1299,6 @@ static inline int nfs_commit_list(struct inode *inode, struct list_head *head, i 
long nfs_sync_mapping_wait(struct address_space *mapping, struct writeback_control *wbc, int how)

{

	struct inode *inode = mapping->host;

	struct nfs_inode *nfsi = NFS_I(inode);

	pgoff_t idx_start, idx_end;

	unsigned int npages = 0;

	LIST_HEAD(head);
@@ -1323,7 +1320,7 @@ long nfs_sync_mapping_wait(struct address_space *mapping, struct writeback_contr 
		}

	}

	how &= ~FLUSH_NOCOMMIT;

	spin_lock(&nfsi->req_lock);

	spin_lock(&inode->i_lock);

	do {

		ret = nfs_wait_on_requests_locked(inode, idx_start, npages);

		if (ret != 0)
@@ -1334,18 +1331,19 @@ long nfs_sync_mapping_wait(struct address_space *mapping, struct writeback_contr 
		if (pages == 0)

			break;

		if (how & FLUSH_INVALIDATE) {

			spin_unlock(&nfsi->req_lock);

			spin_unlock(&inode->i_lock);

			nfs_cancel_commit_list(&head);

			ret = pages;

			spin_lock(&nfsi->req_lock);

			spin_lock(&inode->i_lock);

			continue;

		}

		pages += nfs_scan_commit(inode, &head, 0, 0);

		spin_unlock(&nfsi->req_lock);

		spin_unlock(&inode->i_lock);

		ret = nfs_commit_list(inode, &head, how);

		spin_lock(&nfsi->req_lock);

		spin_lock(&inode->i_lock);



	} while (ret >= 0);

	spin_unlock(&nfsi->req_lock);

	spin_unlock(&inode->i_lock);

	return ret;

}
@@ -1439,7 +1437,6 @@ int nfs_set_page_dirty(struct page *page) 
{

	struct address_space *mapping = page->mapping;

	struct inode *inode;

	spinlock_t *req_lock;

	struct nfs_page *req;

	int ret;
@@ -1448,18 +1445,17 @@ int nfs_set_page_dirty(struct page *page) 
	inode = mapping->host;

	if (!inode)

		goto out_raced;

	req_lock = &NFS_I(inode)->req_lock;

	spin_lock(req_lock);

	spin_lock(&inode->i_lock);

	req = nfs_page_find_request_locked(page);

	if (req != NULL) {

		/* Mark any existing write requests for flushing */

		ret = !test_and_set_bit(PG_NEED_FLUSH, &req->wb_flags);

		spin_unlock(req_lock);

		spin_unlock(&inode->i_lock);

		nfs_release_request(req);

		return ret;

	}

	ret = __set_page_dirty_nobuffers(page);

	spin_unlock(req_lock);

	spin_unlock(&inode->i_lock);

	return ret;

out_raced:

	return !TestSetPageDirty(page);

include/linux/nfs_fs.h

+0 −1
Original line number Diff line number Diff line
@@ -156,7 +156,6 @@ struct nfs_inode { 
	/*

	 * This is the list of dirty unwritten pages.

	 */

	spinlock_t		req_lock;

	struct radix_tree_root	nfs_page_tree;



	unsigned long		ncommit,