2019-10-02 04:34:04

by Trond Myklebust

[permalink] [raw]
Subject: [PATCH v2 2/2] 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 <[email protected]>
---
fs/nfs/direct.c | 41 -----------------------------------------
1 file changed, 41 deletions(-)

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 62cb4a1a87f0..c959d7a3044c 100644
--- 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 */
@@ -127,7 +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];
loff_t hdr_arg = hdr->io_start + hdr->args.count;
ssize_t expected = 0;

@@ -146,15 +135,12 @@ nfs_direct_handle_truncated(struct nfs_direct_req *dreq,
else if (hdr->good_bytes > 0)
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;

@@ -166,8 +152,6 @@ 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;
}
@@ -314,18 +298,6 @@ 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;
@@ -340,7 +312,6 @@ 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;
@@ -659,7 +630,6 @@ 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);
@@ -670,21 +640,12 @@ 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++;
@@ -702,7 +663,6 @@ 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);
@@ -935,7 +895,6 @@ 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;
--
2.21.0