From a6305ddb080fb483ca41ca56cacb6f96089f0c8e Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 9 Apr 2010 19:07:08 -0400 Subject: [PATCH] NFS: Fix a race with the new commit code This patch fixes a race which occurs due to the fact that we release the PG_writeback flag while still holding the nfs_page locked. Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 7f40ea3..40297c4 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -201,6 +201,7 @@ static int nfs_set_page_writeback(struct page *page) struct inode *inode = page->mapping->host; struct nfs_server *nfss = NFS_SERVER(inode); + page_cache_get(page); if (atomic_long_inc_return(&nfss->writeback) > NFS_CONGESTION_ON_THRESH) { set_bdi_congested(&nfss->backing_dev_info, @@ -216,6 +217,7 @@ static void nfs_end_page_writeback(struct page *page) struct nfs_server *nfss = NFS_SERVER(inode); end_page_writeback(page); + page_cache_release(page); if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH) clear_bdi_congested(&nfss->backing_dev_info, BLK_RW_ASYNC); } @@ -665,6 +667,7 @@ static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page, /* Update file length */ nfs_grow_file(page, offset, count); nfs_mark_uptodate(page, req->wb_pgbase, req->wb_bytes); + nfs_mark_request_dirty(req); nfs_clear_page_tag_locked(req); return 0; } @@ -749,13 +752,12 @@ int nfs_updatepage(struct file *file, struct page *page, static void nfs_writepage_release(struct nfs_page *req) { + struct page *page = req->wb_page; - if (PageError(req->wb_page) || !nfs_reschedule_unstable_write(req)) { - nfs_end_page_writeback(req->wb_page); + if (PageError(req->wb_page) || !nfs_reschedule_unstable_write(req)) nfs_inode_remove_request(req); - } else - nfs_end_page_writeback(req->wb_page); nfs_clear_page_tag_locked(req); + nfs_end_page_writeback(page); } static int flush_task_priority(int how) @@ -847,9 +849,11 @@ static int nfs_write_rpcsetup(struct nfs_page *req, */ static void nfs_redirty_request(struct nfs_page *req) { + struct page *page = req->wb_page; + nfs_mark_request_dirty(req); - nfs_end_page_writeback(req->wb_page); nfs_clear_page_tag_locked(req); + nfs_end_page_writeback(page); } /* @@ -1084,16 +1088,15 @@ static void nfs_writeback_release_full(void *calldata) if (nfs_write_need_commit(data)) { memcpy(&req->wb_verf, &data->verf, sizeof(req->wb_verf)); nfs_mark_request_commit(req); - nfs_end_page_writeback(page); dprintk(" marked for commit\n"); goto next; } dprintk(" OK\n"); remove_request: - nfs_end_page_writeback(page); nfs_inode_remove_request(req); next: nfs_clear_page_tag_locked(req); + nfs_end_page_writeback(page); } nfs_writedata_release(calldata); } -- 2.7.4