From: Weston Andros Adamson <dros@xxxxxxxxxxxxxxx>
The current mirroring code only notices short writes to the first
mirror. This patch keeps per-mirror byte counts and only considers
a byte to be written once all mirrors report so.
Signed-off-by: Weston Andros Adamson <dros@xxxxxxxxxxxxxxx>
---
fs/nfs/direct.c | 71 +++++++++++++++++++++++++++++++++++++++++++++------------
1 file changed, 57 insertions(+), 14 deletions(-)
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 0178d4f..651387b 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -66,6 +66,10 @@ 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 */
@@ -78,6 +82,10 @@ struct nfs_direct_req {
/* completion state */
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;
+
ssize_t count, /* bytes actually processed */
bytes_left, /* bytes left to be sent */
error; /* any reported error */
@@ -108,6 +116,29 @@ static inline int put_dreq(struct nfs_direct_req *dreq)
return atomic_dec_and_test(&dreq->io_count);
}
+static void
+nfs_direct_good_bytes(struct nfs_direct_req *dreq, struct nfs_pgio_header *hdr)
+{
+ int i;
+ ssize_t count;
+
+ WARN_ON_ONCE(hdr->pgio_mirror_idx >= dreq->mirror_count);
+
+ dreq->mirrors[hdr->pgio_mirror_idx].count += hdr->good_bytes;
+
+ if (hdr->pgio_mirror_idx == 0)
+ dreq->count += hdr->good_bytes;
+
+ /* update the dreq->count by finding the minimum agreed count from all
+ * mirrors */
+ count = dreq->mirrors[0].count;
+
+ for (i = 1; i < dreq->mirror_count; i++)
+ count = min(count, dreq->mirrors[i].count);
+
+ dreq->count = count;
+}
+
/*
* nfs_direct_select_verf - select the right verifier
* @dreq - direct request possibly spanning multiple servers
@@ -241,6 +272,18 @@ 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;
@@ -255,6 +298,7 @@ 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;
@@ -360,14 +404,9 @@ static void nfs_direct_read_completion(struct nfs_pgio_header *hdr)
spin_lock(&dreq->lock);
if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) && (hdr->good_bytes == 0))
dreq->error = hdr->error;
- else {
- /*
- * FIXME: right now this only accounts for bytes written
- * to the first mirror
- */
- if (hdr->pgio_mirror_idx == 0)
- dreq->count += hdr->good_bytes;
- }
+ else
+ nfs_direct_good_bytes(dreq, hdr);
+
spin_unlock(&dreq->lock);
while (!list_empty(&hdr->pages)) {
@@ -598,17 +637,23 @@ 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);
dreq->count = 0;
+ 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);
+
list_for_each_entry_safe(req, tmp, &reqs, wb_list) {
if (!nfs_pageio_add_request(&desc, req)) {
nfs_list_remove_request(req);
@@ -730,12 +775,7 @@ static void nfs_direct_write_completion(struct nfs_pgio_header *hdr)
dreq->error = hdr->error;
}
if (dreq->error == 0) {
- /*
- * FIXME: right now this only accounts for bytes written
- * to the first mirror
- */
- if (hdr->pgio_mirror_idx == 0)
- dreq->count += hdr->good_bytes;
+ nfs_direct_good_bytes(dreq, hdr);
if (nfs_write_need_commit(hdr)) {
if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES)
request_commit = true;
@@ -841,6 +881,9 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
result = PTR_ERR(req);
break;
}
+
+ nfs_direct_setup_mirroring(dreq, &desc, req);
+
nfs_lock_request(req);
req->wb_index = pos >> PAGE_SHIFT;
req->wb_offset = pos & ~PAGE_MASK;
--
1.9.3
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