Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e824f99a authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFSv4: Use a mutex to protect the per-inode commit lists 



The commit lists can get very large, so using the inode->i_lock can
end up affecting general metadata performance.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
parent b30d2f04

fs/nfs/direct.c

+2 −2
Original line number Diff line number Diff line
@@ -616,13 +616,13 @@ nfs_direct_write_scan_commit_list(struct inode *inode, 
				  struct list_head *list,

				  struct nfs_commit_info *cinfo)

{

	spin_lock(&cinfo->inode->i_lock);

	mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);

#ifdef CONFIG_NFS_V4_1

	if (cinfo->ds != NULL && cinfo->ds->nwritten != 0)

		NFS_SERVER(inode)->pnfs_curr_ld->recover_commit_reqs(list, cinfo);

#endif

	nfs_scan_commit_list(&cinfo->mds->list, list, cinfo, 0);

	spin_unlock(&cinfo->inode->i_lock);

	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);

}



static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)

fs/nfs/inode.c

+1 −0
Original line number Diff line number Diff line
@@ -2016,6 +2016,7 @@ static void init_once(void *foo) 
	nfsi->commit_info.ncommit = 0;

	atomic_set(&nfsi->commit_info.rpcs_out, 0);

	init_rwsem(&nfsi->rmdir_sem);

	mutex_init(&nfsi->commit_mutex);

	nfs4_init_once(nfsi);

}

fs/nfs/pnfs_nfs.c

+7 −8
Original line number Diff line number Diff line
@@ -98,14 +98,13 @@ pnfs_generic_transfer_commit_list(struct list_head *src, struct list_head *dst, 
		if (!nfs_lock_request(req))

			continue;

		kref_get(&req->wb_kref);

		if (cond_resched_lock(&cinfo->inode->i_lock))

			list_safe_reset_next(req, tmp, wb_list);

		nfs_request_remove_commit_list(req, cinfo);

		clear_bit(PG_COMMIT_TO_DS, &req->wb_flags);

		nfs_list_add_request(req, dst);

		ret++;

		if ((ret == max) && !cinfo->dreq)

			break;

		cond_resched();

	}

	return ret;

}
@@ -119,7 +118,7 @@ pnfs_generic_scan_ds_commit_list(struct pnfs_commit_bucket *bucket, 
	struct list_head *dst = &bucket->committing;

	int ret;



	lockdep_assert_held(&cinfo->inode->i_lock);

	lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);

	ret = pnfs_generic_transfer_commit_list(src, dst, cinfo, max);

	if (ret) {

		cinfo->ds->nwritten -= ret;
@@ -142,7 +141,7 @@ int pnfs_generic_scan_commit_lists(struct nfs_commit_info *cinfo, 
{

	int i, rv = 0, cnt;



	lockdep_assert_held(&cinfo->inode->i_lock);

	lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);

	for (i = 0; i < cinfo->ds->nbuckets && max != 0; i++) {

		cnt = pnfs_generic_scan_ds_commit_list(&cinfo->ds->buckets[i],

						       cinfo, max);
@@ -162,7 +161,7 @@ void pnfs_generic_recover_commit_reqs(struct list_head *dst, 
	int nwritten;

	int i;



	lockdep_assert_held(&cinfo->inode->i_lock);

	lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);

restart:

	for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {

		nwritten = pnfs_generic_transfer_commit_list(&b->written,
@@ -953,12 +952,12 @@ pnfs_layout_mark_request_commit(struct nfs_page *req, 
	struct list_head *list;

	struct pnfs_commit_bucket *buckets;



	spin_lock(&cinfo->inode->i_lock);

	mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);

	buckets = cinfo->ds->buckets;

	list = &buckets[ds_commit_idx].written;

	if (list_empty(list)) {

		if (!pnfs_is_valid_lseg(lseg)) {

			spin_unlock(&cinfo->inode->i_lock);

			mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);

			cinfo->completion_ops->resched_write(cinfo, req);

			return;

		}
@@ -975,7 +974,7 @@ pnfs_layout_mark_request_commit(struct nfs_page *req, 
	cinfo->ds->nwritten++;



	nfs_request_add_commit_list_locked(req, list, cinfo);

	spin_unlock(&cinfo->inode->i_lock);

	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);

	nfs_mark_page_unstable(req->wb_page, cinfo);

}

EXPORT_SYMBOL_GPL(pnfs_layout_mark_request_commit);

fs/nfs/write.c

+12 −12
Original line number Diff line number Diff line
@@ -195,7 +195,7 @@ nfs_page_find_swap_request(struct page *page) 
	struct nfs_page *req = NULL;

	if (!PageSwapCache(page))

		return NULL;

	spin_lock(&inode->i_lock);

	mutex_lock(&nfsi->commit_mutex);

	if (PageSwapCache(page)) {

		req = nfs_page_search_commits_for_head_request_locked(nfsi,

			page);
@@ -204,7 +204,7 @@ nfs_page_find_swap_request(struct page *page) 
			kref_get(&req->wb_kref);

		}

	}

	spin_unlock(&inode->i_lock);

	mutex_unlock(&nfsi->commit_mutex);

	return req;

}
@@ -856,7 +856,8 @@ nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi, 
 * number of outstanding requests requiring a commit as well as

 * the MM page stats.

 *

 * The caller must hold cinfo->inode->i_lock, and the nfs_page lock.

 * The caller must hold NFS_I(cinfo->inode)->commit_mutex, and the

 * nfs_page lock.

 */

void

nfs_request_add_commit_list_locked(struct nfs_page *req, struct list_head *dst,
@@ -884,9 +885,9 @@ EXPORT_SYMBOL_GPL(nfs_request_add_commit_list_locked); 
void

nfs_request_add_commit_list(struct nfs_page *req, struct nfs_commit_info *cinfo)

{

	spin_lock(&cinfo->inode->i_lock);

	mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);

	nfs_request_add_commit_list_locked(req, &cinfo->mds->list, cinfo);

	spin_unlock(&cinfo->inode->i_lock);

	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);

	if (req->wb_page)

		nfs_mark_page_unstable(req->wb_page, cinfo);

}
@@ -964,11 +965,11 @@ nfs_clear_request_commit(struct nfs_page *req) 
		struct nfs_commit_info cinfo;



		nfs_init_cinfo_from_inode(&cinfo, inode);

		spin_lock(&inode->i_lock);

		mutex_lock(&NFS_I(inode)->commit_mutex);

		if (!pnfs_clear_request_commit(req, &cinfo)) {

			nfs_request_remove_commit_list(req, &cinfo);

		}

		spin_unlock(&inode->i_lock);

		mutex_unlock(&NFS_I(inode)->commit_mutex);

		nfs_clear_page_commit(req->wb_page);

	}

}
@@ -1027,7 +1028,7 @@ nfs_reqs_to_commit(struct nfs_commit_info *cinfo) 
	return cinfo->mds->ncommit;

}



/* cinfo->inode->i_lock held by caller */

/* NFS_I(cinfo->inode)->commit_mutex held by caller */

int

nfs_scan_commit_list(struct list_head *src, struct list_head *dst,

		     struct nfs_commit_info *cinfo, int max)
@@ -1039,13 +1040,12 @@ nfs_scan_commit_list(struct list_head *src, struct list_head *dst, 
		if (!nfs_lock_request(req))

			continue;

		kref_get(&req->wb_kref);

		if (cond_resched_lock(&cinfo->inode->i_lock))

			list_safe_reset_next(req, tmp, wb_list);

		nfs_request_remove_commit_list(req, cinfo);

		nfs_list_add_request(req, dst);

		ret++;

		if ((ret == max) && !cinfo->dreq)

			break;

		cond_resched();

	}

	return ret;

}
@@ -1065,7 +1065,7 @@ nfs_scan_commit(struct inode *inode, struct list_head *dst, 
{

	int ret = 0;



	spin_lock(&cinfo->inode->i_lock);

	mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);

	if (cinfo->mds->ncommit > 0) {

		const int max = INT_MAX;
@@ -1073,7 +1073,7 @@ nfs_scan_commit(struct inode *inode, struct list_head *dst, 
					   cinfo, max);

		ret += pnfs_scan_commit_lists(inode, cinfo, max - ret);

	}

	spin_unlock(&cinfo->inode->i_lock);

	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);

	return ret;

}

include/linux/nfs_fs.h

+1 −0
Original line number Diff line number Diff line
@@ -163,6 +163,7 @@ struct nfs_inode { 
	/* Readers: in-flight sillydelete RPC calls */

	/* Writers: rmdir */

	struct rw_semaphore	rmdir_sem;

	struct mutex		commit_mutex;



#if IS_ENABLED(CONFIG_NFS_V4)

	struct nfs4_cached_acl	*nfs4_acl;