NFS: create common nfs_pgio_header for both read and write
In order to avoid duplicating all the data in nfs_read_data whenever we
split it up into multiple RPC calls (either due to a short read result
or due to rsize < PAGE_SIZE), we split out the bits that are the same
per RPC call into a separate "header" structure.
The goal this patch moves towards is to have a single header
refcounted by several rpc_data structures. Thus, want to always refer
from rpc_data to the header, and not the other way. This patch comes
close to that ideal, but the directio code currently needs some
special casing, isolated in the nfs_direct_[read_write]hdr_release()
functions. This will be dealt with in a future patch.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 8fb036a..fee3241 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1168,52 +1168,58 @@
#define NFS_PAGEVEC_SIZE (8U)
struct nfs_read_data {
+ struct nfs_pgio_header *header;
+ struct list_head list;
struct rpc_task task;
- struct inode *inode;
- struct rpc_cred *cred;
struct nfs_fattr fattr; /* fattr storage */
- struct list_head pages; /* Coalesced read requests */
- struct list_head list; /* lists of struct nfs_read_data */
- struct nfs_page *req; /* multi ops per nfs_page */
struct page **pagevec;
unsigned int npages; /* Max length of pagevec */
struct nfs_readargs args;
struct nfs_readres res;
unsigned long timestamp; /* For lease renewal */
- struct pnfs_layout_segment *lseg;
- struct nfs_client *ds_clp; /* pNFS data server */
- const struct rpc_call_ops *mds_ops;
int (*read_done_cb) (struct rpc_task *task, struct nfs_read_data *data);
__u64 mds_offset;
- int pnfs_error;
struct page *page_array[NFS_PAGEVEC_SIZE];
+ struct nfs_client *ds_clp; /* pNFS data server */
+};
+
+struct nfs_pgio_header {
+ struct inode *inode;
+ struct rpc_cred *cred;
+ struct list_head pages;
+ struct nfs_page *req;
+ struct pnfs_layout_segment *lseg;
+ const struct rpc_call_ops *mds_ops;
+ int pnfs_error;
+};
+
+struct nfs_read_header {
+ struct nfs_pgio_header header;
+ struct nfs_read_data rpc_data;
};
struct nfs_direct_req;
struct nfs_write_data {
+ struct nfs_pgio_header *header;
+ struct list_head list;
struct rpc_task task;
- struct inode *inode;
- struct rpc_cred *cred;
struct nfs_fattr fattr;
struct nfs_writeverf verf;
- struct list_head pages; /* Coalesced requests we wish to flush */
- struct list_head list; /* lists of struct nfs_write_data */
- struct nfs_page *req; /* multi ops per nfs_page */
struct page **pagevec;
unsigned int npages; /* Max length of pagevec */
struct nfs_writeargs args; /* argument struct */
struct nfs_writeres res; /* result struct */
- struct pnfs_layout_segment *lseg;
- struct nfs_client *ds_clp; /* pNFS data server */
- const struct rpc_call_ops *mds_ops;
- int (*write_done_cb) (struct rpc_task *task, struct nfs_write_data *data);
-#ifdef CONFIG_NFS_V4
unsigned long timestamp; /* For lease renewal */
-#endif
+ int (*write_done_cb) (struct rpc_task *task, struct nfs_write_data *data);
__u64 mds_offset; /* Filelayout dense stripe */
- int pnfs_error;
struct page *page_array[NFS_PAGEVEC_SIZE];
+ struct nfs_client *ds_clp; /* pNFS data server */
+};
+
+struct nfs_write_header {
+ struct nfs_pgio_header header;
+ struct nfs_write_data rpc_data;
};
struct nfs_commit_data {