| From 440862bc7c8a92e1875ef23526fd6b9fe33dcdec Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Thu, 17 Jun 2021 19:26:52 -0400 |
| Subject: nfsd: Reduce contention for the nfsd_file nf_rwsem |
| |
| From: Trond Myklebust <trond.myklebust@hammerspace.com> |
| |
| [ Upstream commit 474bc334698df98ce07c890f1898c7e7f389b0c7 ] |
| |
| When flushing out the unstable file writes as part of a COMMIT call, try |
| to perform most of of the data writes and waits outside the semaphore. |
| |
| This means that if the client is sending the COMMIT as part of a memory |
| reclaim operation, then it can continue performing I/O, with contention |
| for the lock occurring only once the data sync is finished. |
| |
| Fixes: 5011af4c698a ("nfsd: Fix stable writes") |
| Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> |
| Tested-by: Chuck Lever <chuck.lever@oracle.com> |
| Signed-off-by: J. Bruce Fields <bfields@redhat.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| fs/nfsd/vfs.c | 18 ++++++++++++++++-- |
| 1 file changed, 16 insertions(+), 2 deletions(-) |
| |
| diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c |
| index fd6be35a1642..f83a1d122505 100644 |
| --- a/fs/nfsd/vfs.c |
| +++ b/fs/nfsd/vfs.c |
| @@ -1123,6 +1123,19 @@ out: |
| } |
| |
| #ifdef CONFIG_NFSD_V3 |
| +static int |
| +nfsd_filemap_write_and_wait_range(struct nfsd_file *nf, loff_t offset, |
| + loff_t end) |
| +{ |
| + struct address_space *mapping = nf->nf_file->f_mapping; |
| + int ret = filemap_fdatawrite_range(mapping, offset, end); |
| + |
| + if (ret) |
| + return ret; |
| + filemap_fdatawait_range_keep_errors(mapping, offset, end); |
| + return 0; |
| +} |
| + |
| /* |
| * Commit all pending writes to stable storage. |
| * |
| @@ -1153,10 +1166,11 @@ nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, |
| if (err) |
| goto out; |
| if (EX_ISSYNC(fhp->fh_export)) { |
| - int err2; |
| + int err2 = nfsd_filemap_write_and_wait_range(nf, offset, end); |
| |
| down_write(&nf->nf_rwsem); |
| - err2 = vfs_fsync_range(nf->nf_file, offset, end, 0); |
| + if (!err2) |
| + err2 = vfs_fsync_range(nf->nf_file, offset, end, 0); |
| switch (err2) { |
| case 0: |
| nfsd_copy_boot_verifier(verf, net_generic(nf->nf_net, |
| -- |
| 2.30.2 |
| |