We require all NFS I/O subrequests to duplicate the lock context as well
as the open context.
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
---
fs/nfs/pagelist.c | 93 ++++++++++++++++++++++++++++-------------------
1 file changed, 55 insertions(+), 38 deletions(-)
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index e9f39fa5964b..66a5c5d4a777 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -295,25 +295,13 @@ nfs_page_group_destroy(struct kref *kref)
nfs_release_request(head);
}
-/**
- * nfs_create_request - Create an NFS read/write request.
- * @ctx: open context to use
- * @page: page to write
- * @last: last nfs request created for this page group or NULL if head
- * @offset: starting offset within the page for the write
- * @count: number of bytes to read/write
- *
- * The page must be locked by the caller. This makes sure we never
- * create two different requests for the same page.
- * User should ensure it is safe to sleep in this function.
- */
-struct nfs_page *
-nfs_create_request(struct nfs_open_context *ctx, struct page *page,
- struct nfs_page *last, unsigned int offset,
- unsigned int count)
+static struct nfs_page *
+__nfs_create_request(struct nfs_lock_context *l_ctx, struct page *page,
+ struct nfs_page *last, unsigned int pgbase,
+ unsigned int offset, unsigned int count)
{
struct nfs_page *req;
- struct nfs_lock_context *l_ctx;
+ struct nfs_open_context *ctx = l_ctx->open_context;
if (test_bit(NFS_CONTEXT_BAD, &ctx->flags))
return ERR_PTR(-EBADF);
@@ -322,13 +310,8 @@ nfs_create_request(struct nfs_open_context *ctx, struct page *page,
if (req == NULL)
return ERR_PTR(-ENOMEM);
- /* get lock context early so we can deal with alloc failures */
- l_ctx = nfs_get_lock_context(ctx);
- if (IS_ERR(l_ctx)) {
- nfs_page_free(req);
- return ERR_CAST(l_ctx);
- }
req->wb_lock_context = l_ctx;
+ refcount_inc(&l_ctx->count);
atomic_inc(&l_ctx->io_count);
/* Initialize the request struct. Initially, we assume a
@@ -340,7 +323,7 @@ nfs_create_request(struct nfs_open_context *ctx, struct page *page,
get_page(page);
}
req->wb_offset = offset;
- req->wb_pgbase = offset;
+ req->wb_pgbase = pgbase;
req->wb_bytes = count;
req->wb_context = get_nfs_open_context(ctx);
kref_init(&req->wb_kref);
@@ -348,6 +331,49 @@ nfs_create_request(struct nfs_open_context *ctx, struct page *page,
return req;
}
+/**
+ * nfs_create_request - Create an NFS read/write request.
+ * @ctx: open context to use
+ * @page: page to write
+ * @last: last nfs request created for this page group or NULL if head
+ * @offset: starting offset within the page for the write
+ * @count: number of bytes to read/write
+ *
+ * The page must be locked by the caller. This makes sure we never
+ * create two different requests for the same page.
+ * User should ensure it is safe to sleep in this function.
+ */
+struct nfs_page *
+nfs_create_request(struct nfs_open_context *ctx, struct page *page,
+ struct nfs_page *last, unsigned int offset,
+ unsigned int count)
+{
+ struct nfs_lock_context *l_ctx = nfs_get_lock_context(ctx);
+ struct nfs_page *ret;
+
+ if (IS_ERR(l_ctx))
+ return ERR_CAST(l_ctx);
+ ret = __nfs_create_request(l_ctx, page, last, offset, offset, count);
+ nfs_put_lock_context(l_ctx);
+ return ret;
+}
+
+static struct nfs_page *
+nfs_create_subreq(struct nfs_page *req, struct nfs_page *last,
+ unsigned int pgbase, unsigned int offset,
+ unsigned int count)
+{
+ struct nfs_page *ret;
+
+ ret = __nfs_create_request(req->wb_lock_context, req->wb_page, last,
+ pgbase, offset, count);
+ if (!IS_ERR(ret)) {
+ nfs_lock_request(ret);
+ ret->wb_index = req->wb_index;
+ }
+ return ret;
+}
+
/**
* nfs_unlock_request - Unlock request and wake up sleepers.
* @req: pointer to request
@@ -1049,14 +1075,10 @@ static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
pgbase += subreq->wb_bytes;
if (bytes_left) {
- subreq = nfs_create_request(req->wb_context,
- req->wb_page,
- subreq, pgbase, bytes_left);
+ subreq = nfs_create_subreq(req, subreq, pgbase,
+ offset, bytes_left);
if (IS_ERR(subreq))
goto err_ptr;
- nfs_lock_request(subreq);
- subreq->wb_offset = offset;
- subreq->wb_index = req->wb_index;
}
} while (bytes_left > 0);
@@ -1158,19 +1180,14 @@ int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
lastreq = lastreq->wb_this_page)
;
- dupreq = nfs_create_request(req->wb_context,
- req->wb_page, lastreq, pgbase, bytes);
+ dupreq = nfs_create_subreq(req, lastreq,
+ pgbase, offset, bytes);
+ nfs_page_group_unlock(req);
if (IS_ERR(dupreq)) {
- nfs_page_group_unlock(req);
desc->pg_error = PTR_ERR(dupreq);
goto out_failed;
}
-
- nfs_lock_request(dupreq);
- nfs_page_group_unlock(req);
- dupreq->wb_offset = offset;
- dupreq->wb_index = req->wb_index;
} else
dupreq = req;
--
2.20.1
