NFS: Remove redundant mirror tracking in O_DIRECT

We no longer need the extra mirror length tracking in the O_DIRECT code,
as we are able to track the maximum contiguous length in dreq->max_count.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 98a9a0bcdf388b44348942b58208db239b662fbc..040a50fd9bf307d9e2bdd25643a3db9f73dcb64e 100644 (file)
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -64,13 +64,6 @@
 
 static struct kmem_cache *nfs_direct_cachep;
 
-/*
- * This represents a set of asynchronous requests that we're waiting on
- */
-struct nfs_direct_mirror {
-       ssize_t count;
-};
-
 struct nfs_direct_req {
        struct kref             kref;           /* release manager */
 
@@ -84,9 +77,6 @@ struct nfs_direct_req {
        atomic_t                io_count;       /* i/os we're waiting for */
        spinlock_t              lock;           /* protect completion state */
 
-       struct nfs_direct_mirror mirrors[NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX];
-       int                     mirror_count;
-
        loff_t                  io_start;       /* Start offset for I/O */
        ssize_t                 count,          /* bytes actually processed */
                                max_count,      /* max expected count */
@@ -127,8 +117,6 @@ nfs_direct_handle_truncated(struct nfs_direct_req *dreq,
                            const struct nfs_pgio_header *hdr,
                            ssize_t dreq_len)
 {
-       struct nfs_direct_mirror *mirror = &dreq->mirrors[hdr->pgio_mirror_idx];
-
        if (!(test_bit(NFS_IOHDR_ERROR, &hdr->flags) ||
              test_bit(NFS_IOHDR_EOF, &hdr->flags)))
                return;
@@ -142,15 +130,12 @@ nfs_direct_handle_truncated(struct nfs_direct_req *dreq,
                else /* Clear outstanding error if this is EOF */
                        dreq->error = 0;
        }
-       if (mirror->count > dreq_len)
-               mirror->count = dreq_len;
 }
 
 static void
 nfs_direct_count_bytes(struct nfs_direct_req *dreq,
                       const struct nfs_pgio_header *hdr)
 {
-       struct nfs_direct_mirror *mirror = &dreq->mirrors[hdr->pgio_mirror_idx];
        loff_t hdr_end = hdr->io_start + hdr->good_bytes;
        ssize_t dreq_len = 0;
 
@@ -162,8 +147,6 @@ nfs_direct_count_bytes(struct nfs_direct_req *dreq,
        if (dreq_len > dreq->max_count)
                dreq_len = dreq->max_count;
 
-       if (mirror->count < dreq_len)
-               mirror->count = dreq_len;
        if (dreq->count < dreq_len)
                dreq->count = dreq_len;
 }
@@ -310,18 +293,6 @@ void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
        cinfo->completion_ops = &nfs_direct_commit_completion_ops;
 }
 
-static inline void nfs_direct_setup_mirroring(struct nfs_direct_req *dreq,
-                                            struct nfs_pageio_descriptor *pgio,
-                                            struct nfs_page *req)
-{
-       int mirror_count = 1;
-
-       if (pgio->pg_ops->pg_get_mirror_count)
-               mirror_count = pgio->pg_ops->pg_get_mirror_count(pgio, req);
-
-       dreq->mirror_count = mirror_count;
-}
-
 static inline struct nfs_direct_req *nfs_direct_req_alloc(void)
 {
        struct nfs_direct_req *dreq;
@@ -336,7 +307,6 @@ static inline struct nfs_direct_req *nfs_direct_req_alloc(void)
        INIT_LIST_HEAD(&dreq->mds_cinfo.list);
        dreq->verf.committed = NFS_INVALID_STABLE_HOW;  /* not set yet */
        INIT_WORK(&dreq->work, nfs_direct_write_schedule_work);
-       dreq->mirror_count = 1;
        spin_lock_init(&dreq->lock);
 
        return dreq;
@@ -655,7 +625,6 @@ static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
        LIST_HEAD(reqs);
        struct nfs_commit_info cinfo;
        LIST_HEAD(failed);
-       int i;
 
        nfs_init_cinfo_from_dreq(&cinfo, dreq);
        nfs_direct_write_scan_commit_list(dreq->inode, &reqs, &cinfo);
@@ -666,21 +635,12 @@ static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
                dreq->max_count += req->wb_bytes;
        dreq->verf.committed = NFS_INVALID_STABLE_HOW;
        nfs_clear_pnfs_ds_commit_verifiers(&dreq->ds_cinfo);
-       for (i = 0; i < dreq->mirror_count; i++)
-               dreq->mirrors[i].count = 0;
        get_dreq(dreq);
 
        nfs_pageio_init_write(&desc, dreq->inode, FLUSH_STABLE, false,
                              &nfs_direct_write_completion_ops);
        desc.pg_dreq = dreq;
 
-       req = nfs_list_entry(reqs.next);
-       nfs_direct_setup_mirroring(dreq, &desc, req);
-       if (desc.pg_error < 0) {
-               list_splice_init(&reqs, &failed);
-               goto out_failed;
-       }
-
        list_for_each_entry_safe(req, tmp, &reqs, wb_list) {
                /* Bump the transmission count */
                req->wb_nio++;
@@ -698,7 +658,6 @@ static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
        }
        nfs_pageio_complete(&desc);
 
-out_failed:
        while (!list_empty(&failed)) {
                req = nfs_list_entry(failed.next);
                nfs_list_remove_request(req);
@@ -931,7 +890,6 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
                                break;
                        }
 
-                       nfs_direct_setup_mirroring(dreq, &desc, req);
                        if (desc.pg_error < 0) {
                                nfs_free_request(req);
                                result = desc.pg_error;