NFS: make iocb available everywhere in direct read path

Pass the iocb argument all the way down to the direct read request
scheduler, and make it available in nfs_direct_read_result.

Test plan:
Compile the kernel with CONFIG_NFS and CONFIG_NFS_DIRECTIO enabled.
Millions of fsx-odirect ops.  OraSim.

Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 6ecde96..6cbddc5 100644 (file)
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -68,6 +68,8 @@ static kmem_cache_t *nfs_direct_cachep;
 struct nfs_direct_req {
        struct kref             kref;           /* release manager */
        struct list_head        list;           /* nfs_read_data structs */
+       struct file *           filp;           /* file descriptor */
+       struct kiocb *          iocb;           /* controlling i/o request */
        wait_queue_head_t       wait;           /* wait for i/o completion */
        struct inode *          inode;          /* target file of I/O */
        struct page **          pages;          /* pages in our buffer */
@@ -240,8 +242,12 @@ static const struct rpc_call_ops nfs_read_direct_ops = {
  * For each nfs_read_data struct that was allocated on the list, dispatch
  * an NFS READ operation
  */
-static void nfs_direct_read_schedule(struct nfs_direct_req *dreq, struct inode *inode, struct nfs_open_context *ctx, unsigned long user_addr, size_t count, loff_t file_offset)
+static void nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t file_offset)
 {
+       struct file *file = dreq->filp;
+       struct inode *inode = file->f_mapping->host;
+       struct nfs_open_context *ctx = (struct nfs_open_context *)
+                                                       file->private_data;
        struct list_head *list = &dreq->list;
        struct page **pages = dreq->pages;
        size_t rsize = NFS_SERVER(inode)->rsize;
@@ -321,10 +327,11 @@ static ssize_t nfs_direct_read_wait(struct nfs_direct_req *dreq, int intr)
        return (ssize_t) result;
 }
 
-static ssize_t nfs_direct_read(struct inode *inode, struct nfs_open_context *ctx, unsigned long user_addr, size_t count, loff_t file_offset, struct page **pages, unsigned int nr_pages)
+static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t file_offset, struct page **pages, unsigned int nr_pages)
 {
        ssize_t result;
        sigset_t oldset;
+       struct inode *inode = iocb->ki_filp->f_mapping->host;
        struct rpc_clnt *clnt = NFS_CLIENT(inode);
        struct nfs_direct_req *dreq;
 
@@ -335,11 +342,11 @@ static ssize_t nfs_direct_read(struct inode *inode, struct nfs_open_context *ctx
        dreq->pages = pages;
        dreq->npages = nr_pages;
        dreq->inode = inode;
+       dreq->filp = iocb->ki_filp;
 
        nfs_add_stats(inode, NFSIOS_DIRECTREADBYTES, count);
        rpc_clnt_sigmask(clnt, &oldset);
-       nfs_direct_read_schedule(dreq, inode, ctx, user_addr, count,
-                                file_offset);
+       nfs_direct_read_schedule(dreq, user_addr, count, file_offset);
        result = nfs_direct_read_wait(dreq, clnt->cl_intr);
        rpc_clnt_sigunmask(clnt, &oldset);
 
@@ -520,10 +527,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, char __user *buf, size_t count,
        int page_count;
        struct page **pages;
        struct file *file = iocb->ki_filp;
-       struct nfs_open_context *ctx =
-                       (struct nfs_open_context *) file->private_data;
        struct address_space *mapping = file->f_mapping;
-       struct inode *inode = mapping->host;
 
        dprintk("nfs: direct read(%s/%s, %lu@%Ld)\n",
                file->f_dentry->d_parent->d_name.name,
@@ -553,7 +557,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, char __user *buf, size_t count,
                goto out;
        }
 
-       retval = nfs_direct_read(inode, ctx, (unsigned long) buf, count, pos,
+       retval = nfs_direct_read(iocb, (unsigned long) buf, count, pos,
                                                pages, page_count);
        if (retval > 0)
                iocb->ki_pos = pos + retval;