From 17089a29a25a3bfe8d14520cd866b7d635ffe5ba Mon Sep 17 00:00:00 2001 From: Weston Andros Adamson Date: Fri, 11 Jul 2014 10:20:45 -0400 Subject: nfs: mark nfs_page reqs with flag for extra ref Change the use of PG_INODE_REF - set it when taking extra reference on subrequests and take care to only release once for each request. Signed-off-by: Weston Andros Adamson Signed-off-by: Trond Myklebust --- fs/nfs/pagelist.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'fs/nfs/pagelist.c') diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index b6ee3a6ee96d..7368b2130a41 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -251,8 +251,10 @@ nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev) /* grab extra ref if head request has extra ref from * the write/commit path to handle handoff between write * and commit lists */ - if (test_bit(PG_INODE_REF, &prev->wb_head->wb_flags)) + if (test_bit(PG_INODE_REF, &prev->wb_head->wb_flags)) { + set_bit(PG_INODE_REF, &req->wb_flags); kref_get(&req->wb_kref); + } } } -- cgit v1.2.1 From 85710a837c2026aae80b7c64187edf1f10027b0b Mon Sep 17 00:00:00 2001 From: Weston Andros Adamson Date: Fri, 11 Jul 2014 10:20:46 -0400 Subject: nfs: nfs_page should take a ref on the head req nfs_pages that aren't the the head of a group must take a reference on the head as long as ->wb_head is set to it. This stops the head from hitting a refcount of 0 while there is still an active nfs_page for the page group. This avoids kref warnings in the writeback code when the page group head is found and referenced. Signed-off-by: Weston Andros Adamson Signed-off-by: Trond Myklebust --- fs/nfs/pagelist.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'fs/nfs/pagelist.c') diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index 7368b2130a41..05a63593a61f 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -239,15 +239,21 @@ nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev) WARN_ON_ONCE(prev == req); if (!prev) { + /* a head request */ req->wb_head = req; req->wb_this_page = req; } else { + /* a subrequest */ WARN_ON_ONCE(prev->wb_this_page != prev->wb_head); WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &prev->wb_head->wb_flags)); req->wb_head = prev->wb_head; req->wb_this_page = prev->wb_this_page; prev->wb_this_page = req; + /* All subrequests take a ref on the head request until + * nfs_page_group_destroy is called */ + kref_get(&req->wb_head->wb_kref); + /* grab extra ref if head request has extra ref from * the write/commit path to handle handoff between write * and commit lists */ @@ -271,6 +277,10 @@ nfs_page_group_destroy(struct kref *kref) struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref); struct nfs_page *tmp, *next; + /* subrequests must release the ref on the head request */ + if (req->wb_head != req) + nfs_release_request(req->wb_head); + if (!nfs_page_group_sync_on_bit(req, PG_TEARDOWN)) return; -- cgit v1.2.1 From d458138353726ea6dcbc53ae3597e489d0432c25 Mon Sep 17 00:00:00 2001 From: Weston Andros Adamson Date: Fri, 11 Jul 2014 10:20:48 -0400 Subject: nfs: handle multiple reqs in nfs_page_async_flush Change nfs_find_and_lock_request so nfs_page_async_flush can handle multiple requests in a page. There is only one request for a page the first time nfs_page_async_flush is called, but if a write or commit fails, async_flush is called again and there may be multiple requests associated with the page. The solution is to merge all the requests in a page group into a single request before calling nfs_pageio_add_request. Rename nfs_find_and_lock_request to nfs_lock_and_join_requests and change it to first lock all requests for the page, then cancel and merge all subrequests into the head request. Signed-off-by: Weston Andros Adamson Signed-off-by: Trond Myklebust --- fs/nfs/pagelist.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'fs/nfs/pagelist.c') diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index 05a63593a61f..0aefc8102b6b 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -29,8 +29,6 @@ static struct kmem_cache *nfs_page_cachep; static const struct rpc_call_ops nfs_pgio_common_ops; -static void nfs_free_request(struct nfs_page *); - static bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount) { p->npages = pagecount; @@ -406,7 +404,7 @@ static void nfs_clear_request(struct nfs_page *req) * * Note: Should never be called with the spinlock held! */ -static void nfs_free_request(struct nfs_page *req) +void nfs_free_request(struct nfs_page *req) { WARN_ON_ONCE(req->wb_this_page != req); -- cgit v1.2.1 From f563b89b182594f827b4100bd34f916339785a77 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 13 Jul 2014 15:13:19 -0400 Subject: NFS: Don't reset pg_moreio in __nfs_pageio_add_request Once we've started sending unstable NFS writes, we do not want to clear pg_moreio, or we may end up sending the very last request as a stable write if the commit lists are still empty. Do, however, reset pg_moreio in the case where we end up having to recoalesce the write if an attempt to use pNFS failed. Signed-off-by: Trond Myklebust --- fs/nfs/pagelist.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/nfs/pagelist.c') diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index 0aefc8102b6b..17fab89f6358 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -935,7 +935,6 @@ static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, nfs_pageio_doio(desc); if (desc->pg_error < 0) return 0; - desc->pg_moreio = 0; if (desc->pg_recoalesce) return 0; /* retry add_request for this subreq */ @@ -982,6 +981,7 @@ static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc) desc->pg_count = 0; desc->pg_base = 0; desc->pg_recoalesce = 0; + desc->pg_moreio = 0; while (!list_empty(&head)) { struct nfs_page *req; -- cgit v1.2.1