2008-04-19 20:50:34

by Myklebust, Trond

[permalink] [raw]
Subject: [PATCH 05/33] NFS: Ensure that the read code cleans up properly when rpc_run_task() fails

In the case of readpage() we need to ensure that the pages get unlocked,
and that the error is flagged.

In the case of O_DIRECT, we need to ensure that the pages are all released.

Signed-off-by: Trond Myklebust <[email protected]>
---

fs/nfs/direct.c | 19 +++++++++++++------
fs/nfs/read.c | 53 +++++++++++++++++++++++++++++++++--------------------
2 files changed, 46 insertions(+), 26 deletions(-)

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index e442005..9d9085b 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -229,14 +229,20 @@ static void nfs_direct_complete(struct nfs_direct_req *dreq)
static void nfs_direct_read_result(struct rpc_task *task, void *calldata)
{
struct nfs_read_data *data = calldata;
- struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req;

- if (nfs_readpage_result(task, data) != 0)
- return;
+ nfs_readpage_result(task, data);
+}
+
+static void nfs_direct_read_release(void *calldata)
+{
+
+ struct nfs_read_data *data = calldata;
+ struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req;
+ int status = data->task.tk_status;

spin_lock(&dreq->lock);
- if (unlikely(task->tk_status < 0)) {
- dreq->error = task->tk_status;
+ if (unlikely(status < 0)) {
+ dreq->error = status;
spin_unlock(&dreq->lock);
} else {
dreq->count += data->res.count;
@@ -249,11 +255,12 @@ static void nfs_direct_read_result(struct rpc_task *task, void *calldata)

if (put_dreq(dreq))
nfs_direct_complete(dreq);
+ nfs_readdata_release(calldata);
}

static const struct rpc_call_ops nfs_read_direct_ops = {
.rpc_call_done = nfs_direct_read_result,
- .rpc_release = nfs_readdata_release,
+ .rpc_release = nfs_direct_read_release,
};

/*
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index d333f5f..6f9208a 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -338,26 +338,25 @@ int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data)
return 0;
}

-static int nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data)
+static void nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data)
{
struct nfs_readargs *argp = &data->args;
struct nfs_readres *resp = &data->res;

if (resp->eof || resp->count == argp->count)
- return 0;
+ return;

/* This is a short read! */
nfs_inc_stats(data->inode, NFSIOS_SHORTREAD);
/* Has the server at least made some progress? */
if (resp->count == 0)
- return 0;
+ return;

/* Yes, so retry the read at the end of the data */
argp->offset += resp->count;
argp->pgbase += resp->count;
argp->count -= resp->count;
rpc_restart_call(task);
- return -EAGAIN;
}

/*
@@ -366,29 +365,37 @@ static int nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data)
static void nfs_readpage_result_partial(struct rpc_task *task, void *calldata)
{
struct nfs_read_data *data = calldata;
- struct nfs_page *req = data->req;
- struct page *page = req->wb_page;

if (nfs_readpage_result(task, data) != 0)
return;
+ if (task->tk_status < 0)
+ return;

- if (likely(task->tk_status >= 0)) {
- nfs_readpage_truncate_uninitialised_page(data);
- if (nfs_readpage_retry(task, data) != 0)
- return;
- }
- if (unlikely(task->tk_status < 0))
+ nfs_readpage_truncate_uninitialised_page(data);
+ nfs_readpage_retry(task, data);
+}
+
+static void nfs_readpage_release_partial(void *calldata)
+{
+ struct nfs_read_data *data = calldata;
+ struct nfs_page *req = data->req;
+ struct page *page = req->wb_page;
+ int status = data->task.tk_status;
+
+ if (status < 0)
SetPageError(page);
+
if (atomic_dec_and_test(&req->wb_complete)) {
if (!PageError(page))
SetPageUptodate(page);
nfs_readpage_release(req);
}
+ nfs_readdata_release(calldata);
}

static const struct rpc_call_ops nfs_read_partial_ops = {
.rpc_call_done = nfs_readpage_result_partial,
- .rpc_release = nfs_readdata_release,
+ .rpc_release = nfs_readpage_release_partial,
};

static void nfs_readpage_set_pages_uptodate(struct nfs_read_data *data)
@@ -423,29 +430,35 @@ static void nfs_readpage_result_full(struct rpc_task *task, void *calldata)

if (nfs_readpage_result(task, data) != 0)
return;
+ if (task->tk_status < 0)
+ return;
/*
* Note: nfs_readpage_retry may change the values of
* data->args. In the multi-page case, we therefore need
* to ensure that we call nfs_readpage_set_pages_uptodate()
* first.
*/
- if (likely(task->tk_status >= 0)) {
- nfs_readpage_truncate_uninitialised_page(data);
- nfs_readpage_set_pages_uptodate(data);
- if (nfs_readpage_retry(task, data) != 0)
- return;
- }
+ nfs_readpage_truncate_uninitialised_page(data);
+ nfs_readpage_set_pages_uptodate(data);
+ nfs_readpage_retry(task, data);
+}
+
+static void nfs_readpage_release_full(void *calldata)
+{
+ struct nfs_read_data *data = calldata;
+
while (!list_empty(&data->pages)) {
struct nfs_page *req = nfs_list_entry(data->pages.next);

nfs_list_remove_request(req);
nfs_readpage_release(req);
}
+ nfs_readdata_release(calldata);
}

static const struct rpc_call_ops nfs_read_full_ops = {
.rpc_call_done = nfs_readpage_result_full,
- .rpc_release = nfs_readdata_release,
+ .rpc_release = nfs_readpage_release_full,
};

/*