[PATCH v1 5/7] nfs: introduce nfs_direct_extract_pages helper
From: Pranjal Shrivastava
Date: Wed Jun 03 2026 - 01:33:03 EST
Introduce nfs_direct_extract_pages() in direct.c to centralize page
extraction and request creation for the Direct I/O path. The helper
manages extraction from the iters and builds a list of nfs_page requests
Refactor nfs_direct_read_schedule_iovec() and
nfs_direct_write_schedule_iovec() to utilize the new helper, unifying
the extraction logic on both paths.
Signed-off-by: Pranjal Shrivastava <praan@xxxxxxxxxx>
---
fs/nfs/direct.c | 122 +++++++++++++++++++++++-------------------------
1 file changed, 59 insertions(+), 63 deletions(-)
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index b6aaa5f80241..59002c150f23 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -178,6 +178,50 @@ static void nfs_direct_release_pages(struct page **pages, unsigned int npages,
}
}
+static ssize_t nfs_direct_extract_pages(struct nfs_direct_req *dreq,
+ struct iov_iter *iter,
+ size_t size, loff_t *pos,
+ struct list_head *list)
+{
+ bool pinned = iov_iter_extract_will_pin(iter);
+ struct page **pagevec = NULL;
+ ssize_t result, bytes = 0;
+ unsigned int npages, i;
+ size_t pgbase;
+
+ result = iov_iter_extract_pages(iter, &pagevec, size, ~0U, 0, &pgbase);
+ if (result <= 0)
+ return result;
+
+ npages = (result + pgbase + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ for (i = 0; i < npages; i++) {
+ struct nfs_page *req;
+ unsigned int req_len = min_t(size_t, result - bytes, PAGE_SIZE - pgbase);
+
+ req = nfs_page_create_from_page(dreq->ctx, pagevec[i],
+ pinned, pgbase, *pos,
+ req_len);
+ if (IS_ERR(req)) {
+ if (!bytes)
+ bytes = PTR_ERR(req);
+ break;
+ }
+
+ list_add_tail(&req->wb_list, list);
+ pgbase = 0;
+ bytes += req_len;
+ *pos += req_len;
+ }
+
+ if (i < npages) {
+ iov_iter_revert(iter, result - bytes);
+ nfs_direct_release_pages(pagevec + i, npages - i, pinned);
+ }
+
+ kvfree(pagevec);
+ return bytes;
+}
+
void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
struct nfs_direct_req *dreq)
{
@@ -346,6 +390,7 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
ssize_t result = -EINVAL;
size_t requested_bytes = 0;
size_t rsize = max_t(size_t, NFS_SERVER(inode)->rsize, PAGE_SIZE);
+ LIST_HEAD(nfs_page_list);
nfs_pageio_init_read(&desc, dreq->inode, false,
&nfs_direct_read_completion_ops);
@@ -354,43 +399,22 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
inode_dio_begin(inode);
while (iov_iter_count(iter)) {
- struct page **pagevec = NULL;
- size_t bytes;
- size_t pgbase;
- unsigned npages, i;
- bool pinned = iov_iter_extract_will_pin(iter);
-
- result = iov_iter_extract_pages(iter, &pagevec,
- rsize, ~0U, 0, &pgbase);
+ result = nfs_direct_extract_pages(dreq, iter, rsize, &pos, &nfs_page_list);
if (result < 0)
break;
- bytes = result;
- npages = (result + pgbase + PAGE_SIZE - 1) / PAGE_SIZE;
- for (i = 0; i < npages; i++) {
- struct nfs_page *req;
- unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase);
- /* XXX do we need to do the eof zeroing found in async_filler? */
- req = nfs_page_create_from_page(dreq->ctx, pagevec[i],
- pinned, pgbase, pos,
- req_len);
- if (IS_ERR(req)) {
- result = PTR_ERR(req);
- break;
- }
+ requested_bytes += result;
+ while (!list_empty(&nfs_page_list)) {
+ struct nfs_page *req = nfs_list_entry(nfs_page_list.next);
+
+ nfs_list_remove_request(req);
if (!nfs_pageio_add_request(&desc, req)) {
result = desc.pg_error;
nfs_release_request(req);
+ nfs_release_request_list(&nfs_page_list);
break;
}
- pgbase = 0;
- bytes -= req_len;
- requested_bytes += req_len;
- pos += req_len;
}
- if (i < npages)
- nfs_direct_release_pages(pagevec + i, npages - i, pinned);
- kvfree(pagevec);
if (result < 0)
break;
}
@@ -873,6 +897,7 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
ssize_t result = 0;
size_t requested_bytes = 0;
size_t wsize = max_t(size_t, NFS_SERVER(inode)->wsize, PAGE_SIZE);
+ LIST_HEAD(nfs_page_list);
bool defer = false;
trace_nfs_direct_write_schedule_iovec(dreq);
@@ -885,42 +910,15 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
NFS_I(inode)->write_io += iov_iter_count(iter);
while (iov_iter_count(iter)) {
- struct page **pagevec = NULL;
- size_t bytes;
- size_t pgbase;
- unsigned npages, i;
- bool pinned = iov_iter_extract_will_pin(iter);
-
- result = iov_iter_extract_pages(iter, &pagevec,
- wsize, ~0U, 0, &pgbase);
+ result = nfs_direct_extract_pages(dreq, iter, wsize, &pos, &nfs_page_list);
if (result < 0)
break;
- bytes = result;
- npages = (result + pgbase + PAGE_SIZE - 1) / PAGE_SIZE;
- for (i = 0; i < npages; i++) {
- struct nfs_page *req;
- unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase);
-
- req = nfs_page_create_from_page(dreq->ctx, pagevec[i],
- pinned, pgbase, pos,
- req_len);
- if (IS_ERR(req)) {
- result = PTR_ERR(req);
- break;
- }
-
- if (desc.pg_error < 0) {
- nfs_free_request(req);
- result = desc.pg_error;
- break;
- }
-
- pgbase = 0;
- bytes -= req_len;
- requested_bytes += req_len;
- pos += req_len;
+ requested_bytes += result;
+ while (!list_empty(&nfs_page_list)) {
+ struct nfs_page *req = nfs_list_entry(nfs_page_list.next);
+ nfs_list_remove_request(req);
if (defer) {
nfs_mark_request_commit(req, NULL, &cinfo, 0);
continue;
@@ -934,6 +932,7 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
if (desc.pg_error < 0 && desc.pg_error != -EAGAIN) {
result = desc.pg_error;
nfs_unlock_and_release_request(req);
+ nfs_release_request_list(&nfs_page_list);
break;
}
@@ -947,9 +946,6 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
desc.pg_error = 0;
defer = true;
}
- if (i < npages)
- nfs_direct_release_pages(pagevec + i, npages - i, pinned);
- kvfree(pagevec);
if (result < 0)
break;
}
--
2.54.0.1013.g208068f2d8-goog