nfsd: Add I/O trace points in the NFSv4 write path
NFSv4 write compound processing invokes nfsd_vfs_write directly. The
trace points currently in nfsd_write are not effective for NFSv4
writes.
Move the trace points into the shared nfsd_vfs_write() helper.
After the I/O, we also want to record any local I/O error that
might have occurred, and the total count of bytes that were actually
moved (rather than the requested number).
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 8570319..ee59a0b 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -965,13 +965,15 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
{
struct svc_export *exp;
struct iov_iter iter;
- __be32 err = 0;
+ __be32 nfserr;
int host_err;
int use_wgather;
loff_t pos = offset;
unsigned int pflags = current->flags;
rwf_t flags = 0;
+ trace_nfsd_write_opened(rqstp, fhp, offset, *cnt);
+
if (test_bit(RQ_LOCAL, &rqstp->rq_flags))
/*
* We want less throttling in balance_dirty_pages()
@@ -994,22 +996,23 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
host_err = vfs_iter_write(file, &iter, &pos, flags);
if (host_err < 0)
goto out_nfserr;
- *cnt = host_err;
- nfsdstats.io_write += host_err;
+ nfsdstats.io_write += *cnt;
fsnotify_modify(file);
if (stable && use_wgather)
host_err = wait_for_concurrent_writes(file);
out_nfserr:
- dprintk("nfsd: write complete host_err=%d\n", host_err);
- if (host_err >= 0)
- err = 0;
- else
- err = nfserrno(host_err);
+ if (host_err >= 0) {
+ trace_nfsd_write_io_done(rqstp, fhp, offset, *cnt);
+ nfserr = nfs_ok;
+ } else {
+ trace_nfsd_write_err(rqstp, fhp, offset, host_err);
+ nfserr = nfserrno(host_err);
+ }
if (test_bit(RQ_LOCAL, &rqstp->rq_flags))
current_restore_flags(pflags, PF_LESS_THROTTLE);
- return err;
+ return nfserr;
}
/*
@@ -1067,9 +1070,7 @@ nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
if (err)
goto out;
- trace_nfsd_write_opened(rqstp, fhp, offset, *cnt);
err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt, stable);
- trace_nfsd_write_io_done(rqstp, fhp, offset, *cnt);
fput(file);
out:
trace_nfsd_write_done(rqstp, fhp, offset, *cnt);