From 67f4b5dc49913abcdb5cc736e73674e2f352f81d Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sat, 13 Aug 2022 08:22:25 -0400 Subject: NFS: Fix another fsync() issue after a server reboot Currently, when the writeback code detects a server reboot, it redirties any pages that were not committed to disk, and it sets the flag NFS_CONTEXT_RESEND_WRITES in the nfs_open_context of the file descriptor that dirtied the file. While this allows the file descriptor in question to redrive its own writes, it violates the fsync() requirement that we should be synchronising all writes to disk. While the problem is infrequent, we do see corner cases where an untimely server reboot causes the fsync() call to abandon its attempt to sync data to disk and causing data corruption issues due to missed error conditions or similar. In order to tighted up the client's ability to deal with this situation without introducing livelocks, add a counter that records the number of times pages are redirtied due to a server reboot-like condition, and use that in fsync() to redrive the sync to disk. Fixes: 2197e9b06c22 ("NFS: Fix up fsync() when the server rebooted") Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'fs/nfs/write.c') diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 4a3796811b4b..989c734cf91d 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1420,10 +1420,12 @@ static void nfs_initiate_write(struct nfs_pgio_header *hdr, */ static void nfs_redirty_request(struct nfs_page *req) { + struct nfs_inode *nfsi = NFS_I(page_file_mapping(req->wb_page)->host); + /* Bump the transmission count */ req->wb_nio++; nfs_mark_request_dirty(req); - set_bit(NFS_CONTEXT_RESEND_WRITES, &nfs_req_openctx(req)->flags); + atomic_long_inc(&nfsi->redirtied_pages); nfs_end_page_writeback(req); nfs_release_request(req); } @@ -1904,7 +1906,7 @@ static void nfs_commit_release_pages(struct nfs_commit_data *data) /* We have a mismatch. Write the page again */ dprintk_cont(" mismatch\n"); nfs_mark_request_dirty(req); - set_bit(NFS_CONTEXT_RESEND_WRITES, &nfs_req_openctx(req)->flags); + atomic_long_inc(&NFS_I(data->inode)->redirtied_pages); next: nfs_unlock_and_release_request(req); /* Latency breaker */ -- cgit v1.2.3