2020-01-06 20:27:48

by Trond Myklebust

[permalink] [raw]
Subject: [PATCH 04/15] NFS: Fix up fsync() when the server rebooted

Don't clear the NFS_CONTEXT_RESEND_WRITES flag until after calling
nfs_commit_inode(). Otherwise, if nfs_commit_inode() returns an
error, we end up with dirty pages in the page cache, but no tag
to tell us that those pages need resending.

Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/file.c | 37 ++++++++++++++++---------------------
1 file changed, 16 insertions(+), 21 deletions(-)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 8eb731d9be3e..95a3445c8926 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -204,44 +204,39 @@ EXPORT_SYMBOL_GPL(nfs_file_mmap);
static int
nfs_file_fsync_commit(struct file *file, int datasync)
{
- struct nfs_open_context *ctx = nfs_file_open_context(file);
struct inode *inode = file_inode(file);
- int do_resend, status;
- int ret = 0;
+ int ret;

dprintk("NFS: fsync file(%pD2) datasync %d\n", file, datasync);

nfs_inc_stats(inode, NFSIOS_VFSFSYNC);
- do_resend = test_and_clear_bit(NFS_CONTEXT_RESEND_WRITES, &ctx->flags);
- status = nfs_commit_inode(inode, FLUSH_SYNC);
- if (status == 0)
- status = file_check_and_advance_wb_err(file);
- if (status < 0) {
- ret = status;
- goto out;
- }
- do_resend |= test_bit(NFS_CONTEXT_RESEND_WRITES, &ctx->flags);
- if (do_resend)
- ret = -EAGAIN;
-out:
- return ret;
+ ret = nfs_commit_inode(inode, FLUSH_SYNC);
+ if (ret < 0)
+ return ret;
+ return file_check_and_advance_wb_err(file);
}

int
nfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
{
- int ret;
+ struct nfs_open_context *ctx = nfs_file_open_context(file);
struct inode *inode = file_inode(file);
+ int ret;

trace_nfs_fsync_enter(inode);

- do {
+ for (;;) {
ret = file_write_and_wait_range(file, start, end);
if (ret != 0)
break;
ret = nfs_file_fsync_commit(file, datasync);
- if (!ret)
- ret = pnfs_sync_inode(inode, !!datasync);
+ if (ret != 0)
+ break;
+ ret = pnfs_sync_inode(inode, !!datasync);
+ if (ret != 0)
+ break;
+ if (!test_and_clear_bit(NFS_CONTEXT_RESEND_WRITES, &ctx->flags))
+ break;
/*
* If nfs_file_fsync_commit detected a server reboot, then
* resend all dirty pages that might have been covered by
@@ -249,7 +244,7 @@ nfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
*/
start = 0;
end = LLONG_MAX;
- } while (ret == -EAGAIN);
+ }

trace_nfs_fsync_exit(inode, ret);
return ret;
--
2.24.1


2020-01-06 20:27:48

by Trond Myklebust

[permalink] [raw]
Subject: [PATCH 05/15] NFS/pnfs: Fix pnfs_generic_prepare_to_resend_writes()

Instead of making assumptions about the commit verifier contents, change
the commit code to ensure we always check that the verifier was set
by the XDR code.

Fixes: f54bcf2ecee9 ("pnfs: Prepare for flexfiles by pulling out common code")
Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/direct.c | 4 ++--
fs/nfs/nfs3xdr.c | 5 ++++-
fs/nfs/nfs4xdr.c | 5 ++++-
fs/nfs/pnfs_nfs.c | 7 +++----
fs/nfs/write.c | 4 +++-
5 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 040a50fd9bf3..29f00da8a0b7 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -245,10 +245,10 @@ static int nfs_direct_cmp_commit_data_verf(struct nfs_direct_req *dreq,
data->ds_commit_index);

/* verifier not set so always fail */
- if (verfp->committed < 0)
+ if (verfp->committed < 0 || data->res.verf->committed <= NFS_UNSTABLE)
return 1;

- return nfs_direct_cmp_verf(verfp, &data->verf);
+ return nfs_direct_cmp_verf(verfp, data->res.verf);
}

/**
diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c
index 927eb680f161..69971f6c840d 100644
--- a/fs/nfs/nfs3xdr.c
+++ b/fs/nfs/nfs3xdr.c
@@ -2334,6 +2334,7 @@ static int nfs3_xdr_dec_commit3res(struct rpc_rqst *req,
void *data)
{
struct nfs_commitres *result = data;
+ struct nfs_writeverf *verf = result->verf;
enum nfs_stat status;
int error;

@@ -2346,7 +2347,9 @@ static int nfs3_xdr_dec_commit3res(struct rpc_rqst *req,
result->op_status = status;
if (status != NFS3_OK)
goto out_status;
- error = decode_writeverf3(xdr, &result->verf->verifier);
+ error = decode_writeverf3(xdr, &verf->verifier);
+ if (!error)
+ verf->committed = NFS_FILE_SYNC;
out:
return error;
out_status:
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 936c57779ff4..d0feef17db50 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -4313,11 +4313,14 @@ static int decode_write_verifier(struct xdr_stream *xdr, struct nfs_write_verifi

static int decode_commit(struct xdr_stream *xdr, struct nfs_commitres *res)
{
+ struct nfs_writeverf *verf = res->verf;
int status;

status = decode_op_hdr(xdr, OP_COMMIT);
if (!status)
- status = decode_write_verifier(xdr, &res->verf->verifier);
+ status = decode_write_verifier(xdr, &verf->verifier);
+ if (!status)
+ verf->committed = NFS_FILE_SYNC;
return status;
}

diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c
index 82af4809b869..8b37e7f8e789 100644
--- a/fs/nfs/pnfs_nfs.c
+++ b/fs/nfs/pnfs_nfs.c
@@ -31,12 +31,11 @@ EXPORT_SYMBOL_GPL(pnfs_generic_rw_release);
/* Fake up some data that will cause nfs_commit_release to retry the writes. */
void pnfs_generic_prepare_to_resend_writes(struct nfs_commit_data *data)
{
- struct nfs_page *first = nfs_list_entry(data->pages.next);
+ struct nfs_writeverf *verf = data->res.verf;

data->task.tk_status = 0;
- memcpy(&data->verf.verifier, &first->wb_verf,
- sizeof(data->verf.verifier));
- data->verf.verifier.data[0]++; /* ensure verifier mismatch */
+ memset(&verf->verifier, 0, sizeof(verf->verifier));
+ verf->committed = NFS_UNSTABLE;
}
EXPORT_SYMBOL_GPL(pnfs_generic_prepare_to_resend_writes);

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 83e6f691368c..ab3d4611f0aa 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1838,6 +1838,7 @@ static void nfs_commit_done(struct rpc_task *task, void *calldata)

static void nfs_commit_release_pages(struct nfs_commit_data *data)
{
+ const struct nfs_writeverf *verf = data->res.verf;
struct nfs_page *req;
int status = data->task.tk_status;
struct nfs_commit_info cinfo;
@@ -1865,7 +1866,8 @@ static void nfs_commit_release_pages(struct nfs_commit_data *data)

/* Okay, COMMIT succeeded, apparently. Check the verifier
* returned by the server against all stored verfs. */
- if (!nfs_write_verifier_cmp(&req->wb_verf, &data->verf.verifier)) {
+ if (verf->committed > NFS_UNSTABLE &&
+ !nfs_write_verifier_cmp(&req->wb_verf, &verf->verifier)) {
/* We have a match */
if (req->wb_page)
nfs_inode_remove_request(req);
--
2.24.1