[PATCH 27/32] NFS: Refactor nfs_readpage() and nfs_readpage_async() to use nfs_readdesc
From: David Howells
Date: Mon Jan 25 2021 - 16:41:02 EST
From: Dave Wysochanski <dwysocha@xxxxxxxxxx>
Both nfs_readpage() and nfs_readpages() use similar code.
This patch should be no functional change, and refactors
nfs_readpage_async() to use nfs_readdesc to enable future
merging of nfs_readpage_async() and nfs_readpage_async_filler().
Signed-off-by: Dave Wysochanski <dwysocha@xxxxxxxxxx>
---
fs/nfs/read.c | 62 +++++++++++++++++++++++-------------------------
include/linux/nfs_fs.h | 3 +-
2 files changed, 31 insertions(+), 34 deletions(-)
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 1153c4e0a155..5fda30742a32 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -114,18 +114,23 @@ static void nfs_readpage_release(struct nfs_page *req, int error)
nfs_release_request(req);
}
-int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
+struct nfs_readdesc {
+ struct nfs_pageio_descriptor pgio;
+ struct nfs_open_context *ctx;
+};
+
+int nfs_readpage_async(void *data, struct inode *inode,
struct page *page)
{
+ struct nfs_readdesc *desc = (struct nfs_readdesc *)data;
struct nfs_page *new;
unsigned int len;
- struct nfs_pageio_descriptor pgio;
struct nfs_pgio_mirror *pgm;
len = nfs_page_length(page);
if (len == 0)
return nfs_return_empty_page(page);
- new = nfs_create_request(ctx, page, 0, len);
+ new = nfs_create_request(desc->ctx, page, 0, len);
if (IS_ERR(new)) {
unlock_page(page);
return PTR_ERR(new);
@@ -133,21 +138,21 @@ int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
if (len < PAGE_SIZE)
zero_user_segment(page, len, PAGE_SIZE);
- nfs_pageio_init_read(&pgio, inode, false,
+ nfs_pageio_init_read(&desc->pgio, inode, false,
&nfs_async_read_completion_ops);
- if (!nfs_pageio_add_request(&pgio, new)) {
+ if (!nfs_pageio_add_request(&desc->pgio, new)) {
nfs_list_remove_request(new);
- nfs_readpage_release(new, pgio.pg_error);
+ nfs_readpage_release(new, desc->pgio.pg_error);
}
- nfs_pageio_complete(&pgio);
+ nfs_pageio_complete(&desc->pgio);
/* It doesn't make sense to do mirrored reads! */
- WARN_ON_ONCE(pgio.pg_mirror_count != 1);
+ WARN_ON_ONCE(desc->pgio.pg_mirror_count != 1);
- pgm = &pgio.pg_mirrors[0];
+ pgm = &desc->pgio.pg_mirrors[0];
NFS_I(inode)->read_io += pgm->pg_bytes_written;
- return pgio.pg_error < 0 ? pgio.pg_error : 0;
+ return desc->pgio.pg_error < 0 ? desc->pgio.pg_error : 0;
}
static void nfs_page_group_set_uptodate(struct nfs_page *req)
@@ -312,7 +317,7 @@ static void nfs_readpage_result(struct rpc_task *task,
*/
int nfs_readpage(struct file *filp, struct page *page)
{
- struct nfs_open_context *ctx;
+ struct nfs_readdesc desc;
struct inode *inode = page_file_mapping(page)->host;
int ret;
@@ -339,39 +344,34 @@ int nfs_readpage(struct file *filp, struct page *page)
if (filp == NULL) {
ret = -EBADF;
- ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
- if (ctx == NULL)
+ desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
+ if (desc.ctx == NULL)
goto out_unlock;
} else
- ctx = get_nfs_open_context(nfs_file_open_context(filp));
+ desc.ctx = get_nfs_open_context(nfs_file_open_context(filp));
if (!IS_SYNC(inode)) {
- ret = nfs_readpage_from_fscache(ctx, inode, page);
+ ret = nfs_readpage_from_fscache(desc.ctx, inode, page);
if (ret == 0)
goto out;
}
- xchg(&ctx->error, 0);
- ret = nfs_readpage_async(ctx, inode, page);
+ xchg(&desc.ctx->error, 0);
+ ret = nfs_readpage_async(&desc, inode, page);
if (!ret) {
ret = wait_on_page_locked_killable(page);
if (!PageUptodate(page) && !ret)
- ret = xchg(&ctx->error, 0);
+ ret = xchg(&desc.ctx->error, 0);
}
nfs_add_stats(inode, NFSIOS_READPAGES, 1);
out:
- put_nfs_open_context(ctx);
+ put_nfs_open_context(desc.ctx);
return ret;
out_unlock:
unlock_page(page);
return ret;
}
-struct nfs_readdesc {
- struct nfs_pageio_descriptor *pgio;
- struct nfs_open_context *ctx;
-};
-
static int
readpage_async_filler(void *data, struct page *page)
{
@@ -390,9 +390,9 @@ readpage_async_filler(void *data, struct page *page)
if (len < PAGE_SIZE)
zero_user_segment(page, len, PAGE_SIZE);
- if (!nfs_pageio_add_request(desc->pgio, new)) {
+ if (!nfs_pageio_add_request(&desc->pgio, new)) {
nfs_list_remove_request(new);
- error = desc->pgio->pg_error;
+ error = desc->pgio.pg_error;
nfs_readpage_release(new, error);
goto out;
}
@@ -407,7 +407,6 @@ readpage_async_filler(void *data, struct page *page)
int nfs_readpages(struct file *filp, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
- struct nfs_pageio_descriptor pgio;
struct nfs_pgio_mirror *pgm;
struct nfs_readdesc desc;
struct inode *inode = mapping->host;
@@ -440,17 +439,16 @@ int nfs_readpages(struct file *filp, struct address_space *mapping,
if (ret == 0)
goto read_complete; /* all pages were read */
- desc.pgio = &pgio;
- nfs_pageio_init_read(&pgio, inode, false,
+ nfs_pageio_init_read(&desc.pgio, inode, false,
&nfs_async_read_completion_ops);
ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
- nfs_pageio_complete(&pgio);
+ nfs_pageio_complete(&desc.pgio);
/* It doesn't make sense to do mirrored reads! */
- WARN_ON_ONCE(pgio.pg_mirror_count != 1);
+ WARN_ON_ONCE(desc.pgio.pg_mirror_count != 1);
- pgm = &pgio.pg_mirrors[0];
+ pgm = &desc.pgio.pg_mirrors[0];
NFS_I(inode)->read_io += pgm->pg_bytes_written;
npages = (pgm->pg_bytes_written + PAGE_SIZE - 1) >>
PAGE_SHIFT;
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 681ed98e4ba8..cb0248a34518 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -570,8 +570,7 @@ nfs_have_writebacks(struct inode *inode)
extern int nfs_readpage(struct file *, struct page *);
extern int nfs_readpages(struct file *, struct address_space *,
struct list_head *, unsigned);
-extern int nfs_readpage_async(struct nfs_open_context *, struct inode *,
- struct page *);
+extern int nfs_readpage_async(void *, struct inode *, struct page *);
/*
* inline functions