From: Trond Myklebust <trondmy@gmail.com>
To: "J. Bruce Fields" <bfields@redhat.com>
Cc: linux-nfs@vger.kernel.org
Subject: [PATCH 2/9] nfsd: Fix stable writes
Date: Mon, 6 Jan 2020 13:40:30 -0500 [thread overview]
Message-ID: <20200106184037.563557-3-trond.myklebust@hammerspace.com> (raw)
In-Reply-To: <20200106184037.563557-2-trond.myklebust@hammerspace.com>
Strictly speaking, a stable write error needs to reflect the
write + the commit of that write (and only that write). To
ensure that we don't pick up the write errors from other
writebacks, add a rw_semaphore to provide exclusion.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
fs/nfsd/filecache.c | 1 +
fs/nfsd/filecache.h | 1 +
fs/nfsd/vfs.c | 18 ++++++++++++++++--
3 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index f275c11c4e28..2fadf080ac42 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -195,6 +195,7 @@ nfsd_file_alloc(struct inode *inode, unsigned int may, unsigned int hashval,
__set_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags);
}
nf->nf_mark = NULL;
+ init_rwsem(&nf->nf_rwsem);
trace_nfsd_file_alloc(nf);
}
return nf;
diff --git a/fs/nfsd/filecache.h b/fs/nfsd/filecache.h
index 79a7d6808d97..986c325a54bd 100644
--- a/fs/nfsd/filecache.h
+++ b/fs/nfsd/filecache.h
@@ -46,6 +46,7 @@ struct nfsd_file {
atomic_t nf_ref;
unsigned char nf_may;
struct nfsd_file_mark *nf_mark;
+ struct rw_semaphore nf_rwsem;
};
int nfsd_file_cache_init(void);
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 69cbdb62b262..218b8293c633 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -982,7 +982,18 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
flags |= RWF_SYNC;
iov_iter_kvec(&iter, WRITE, vec, vlen, *cnt);
- host_err = vfs_iter_write(file, &iter, &pos, flags);
+ if (flags & RWF_SYNC) {
+ down_write(&nf->nf_rwsem);
+ host_err = vfs_iter_write(file, &iter, &pos, flags);
+ if (host_err < 0)
+ nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp),
+ nfsd_net_id));
+ up_write(&nf->nf_rwsem);
+ } else {
+ down_read(&nf->nf_rwsem);
+ host_err = vfs_iter_write(file, &iter, &pos, flags);
+ up_read(&nf->nf_rwsem);
+ }
if (host_err < 0)
goto out_nfserr;
*cnt = host_err;
@@ -1097,8 +1108,10 @@ nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
if (err)
goto out;
if (EX_ISSYNC(fhp->fh_export)) {
- int err2 = vfs_fsync_range(nf->nf_file, offset, end, 0);
+ int err2;
+ down_write(&nf->nf_rwsem);
+ err2 = vfs_fsync_range(nf->nf_file, offset, end, 0);
switch (err2) {
case 0:
break;
@@ -1110,6 +1123,7 @@ nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
nfsd_reset_boot_verifier(net_generic(nf->nf_net,
nfsd_net_id));
}
+ up_write(&nf->nf_rwsem);
}
nfsd_file_put(nf);
--
2.24.1
next prev parent reply other threads:[~2020-01-06 18:42 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-06 18:40 [PATCH 0/9] Fix error reporting for NFS writes Trond Myklebust
2020-01-06 18:40 ` [PATCH 1/9] nfsd: Allow nfsd_vfs_write() to take the nfsd_file as an argument Trond Myklebust
2020-01-06 18:40 ` Trond Myklebust [this message]
2020-01-06 18:40 ` [PATCH 3/9] nfsd: Update the boot verifier on stable writes too Trond Myklebust
2020-01-06 18:40 ` [PATCH 4/9] nfsd: Pass the nfsd_file as arguments to nfsd4_clone_file_range() Trond Myklebust
2020-01-06 18:40 ` [PATCH 5/9] nfsd: Ensure exclusion between CLONE and WRITE errors Trond Myklebust
2020-01-06 18:40 ` [PATCH 6/9] sunrpc: Fix potential leaks in sunrpc_cache_unhash() Trond Myklebust
2020-01-06 18:40 ` [PATCH 7/9] sunrpc: clean up cache entry add/remove from hashtable Trond Myklebust
2020-01-06 18:40 ` [PATCH 8/9] nfsd: Ensure sampling of the commit verifier is atomic with the commit Trond Myklebust
2020-01-06 18:40 ` [PATCH 9/9] nfsd: Ensure sampling of the write verifier is atomic with the write Trond Myklebust
2020-01-22 15:27 ` [PATCH 0/9] Fix error reporting for NFS writes J. Bruce Fields
2020-01-22 17:04 ` J. Bruce Fields
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