[PATCH 32/32] NFS: Convert readpage to readahead and use netfs_readahead for fscache
David Howells
dhowells at redhat.com
Mon Jan 25 16:37:29 EST 2021
From: Dave Wysochanski <dwysocha at redhat.com>
The new FS-Cache API does not have a readpages equivalent function,
and instead of fscache_read_or_alloc_pages() it implements a readahead
function, netfs_readahead(). Call netfs_readahead() if fscache is
enabled, and if not, utilize readahead_page() to run through the
pages needed calling readpage_async_filler().
Signed-off-by: Dave Wysochanski <dwysocha at redhat.com>
---
fs/nfs/file.c | 2 +-
fs/nfs/fscache.c | 49 +++++++-------------------------------------
fs/nfs/fscache.h | 28 +++++++++----------------
fs/nfs/read.c | 32 ++++++++++++++---------------
include/linux/nfs_fs.h | 3 +--
include/linux/nfs_iostat.h | 2 +-
6 files changed, 37 insertions(+), 79 deletions(-)
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 63940a7a70be..ebcaa164db5f 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -515,7 +515,7 @@ static void nfs_swap_deactivate(struct file *file)
const struct address_space_operations nfs_file_aops = {
.readpage = nfs_readpage,
- .readpages = nfs_readpages,
+ .readahead = nfs_readahead,
.set_page_dirty = __set_page_dirty_nobuffers,
.writepage = nfs_writepage,
.writepages = nfs_writepages,
diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
index d3445bb1cc9c..b432bf931470 100644
--- a/fs/nfs/fscache.c
+++ b/fs/nfs/fscache.c
@@ -499,51 +499,18 @@ int __nfs_readpage_from_fscache(struct file *filp,
/*
* Retrieve a set of pages from fscache
*/
-int __nfs_readpages_from_fscache(struct nfs_open_context *ctx,
- struct inode *inode,
- struct address_space *mapping,
- struct list_head *pages,
- unsigned *nr_pages)
+int __nfs_readahead_from_fscache(struct nfs_readdesc *desc,
+ struct readahead_control *rac)
{
- unsigned npages = *nr_pages;
- int ret;
+ struct inode *inode = rac->mapping->host;
- dfprintk(FSCACHE, "NFS: nfs_getpages_from_fscache (0x%p/%u/0x%p)\n",
- nfs_i_fscache(inode), npages, inode);
-
- ret = fscache_read_or_alloc_pages(nfs_i_fscache(inode),
- mapping, pages, nr_pages,
- nfs_readpage_from_fscache_complete,
- ctx,
- mapping_gfp_mask(mapping));
- if (*nr_pages < npages)
- nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK,
- npages);
- if (*nr_pages > 0)
- nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL,
- *nr_pages);
+ dfprintk(FSCACHE, "NFS: nfs_readahead_from_fscache (0x%p/0x%p)\n",
+ nfs_i_fscache(inode), inode);
- switch (ret) {
- case 0: /* read submitted to the cache for all pages */
- BUG_ON(!list_empty(pages));
- BUG_ON(*nr_pages != 0);
- dfprintk(FSCACHE,
- "NFS: nfs_getpages_from_fscache: submitted\n");
+ netfs_readahead(rac, &nfs_fscache_req_ops, desc);
- return ret;
-
- case -ENOBUFS: /* some pages aren't cached and can't be */
- case -ENODATA: /* some pages aren't cached */
- dfprintk(FSCACHE,
- "NFS: nfs_getpages_from_fscache: no page: %d\n", ret);
- return 1;
-
- default:
- dfprintk(FSCACHE,
- "NFS: nfs_getpages_from_fscache: ret %d\n", ret);
- }
-
- return ret;
+ /* FIXME: NFSIOS_NFSIOS_FSCACHE_ stats */
+ return 0;
}
/*
diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h
index 4a76a5f31772..d095e513af12 100644
--- a/fs/nfs/fscache.h
+++ b/fs/nfs/fscache.h
@@ -98,11 +98,10 @@ extern int nfs_fscache_release_page(struct page *, gfp_t);
extern int __nfs_readpage_from_fscache(struct file *filp,
struct page *page,
struct nfs_readdesc *desc);
-extern int __nfs_readpages_from_fscache(struct nfs_open_context *,
- struct inode *, struct address_space *,
- struct list_head *, unsigned *);
-extern void __nfs_readpage_to_fscache(struct inode *, struct page *, int);
-
+extern int __nfs_readahead_from_fscache(struct nfs_readdesc *desc,
+ struct readahead_control *rac);
+extern void __nfs_read_completion_to_fscache(struct nfs_pgio_header *hdr,
+ unsigned long bytes);
/*
* wait for a page to complete writing to the cache
*/
@@ -139,15 +138,11 @@ static inline int nfs_readpage_from_fscache(struct file *filp,
/*
* Retrieve a set of pages from an inode data storage object.
*/
-static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
- struct inode *inode,
- struct address_space *mapping,
- struct list_head *pages,
- unsigned *nr_pages)
+static inline int nfs_readahead_from_fscache(struct nfs_readdesc *desc,
+ struct readahead_control *rac)
{
- if (NFS_I(inode)->fscache)
- return __nfs_readpages_from_fscache(ctx, inode, mapping, pages,
- nr_pages);
+ if (NFS_I(rac->mapping->host)->fscache)
+ return __nfs_readahead_from_fscache(desc, rac);
return -ENOBUFS;
}
@@ -217,11 +212,8 @@ static inline int nfs_readpage_from_fscache(struct file *filp,
{
return -ENOBUFS;
}
-static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
- struct inode *inode,
- struct address_space *mapping,
- struct list_head *pages,
- unsigned *nr_pages)
+static inline int nfs_readahead_from_fscache(struct nfs_readdesc *desc,
+ struct readahead_control *rac)
{
return -ENOBUFS;
}
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 7a76ab474fe0..da44ce68488c 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -390,50 +390,50 @@ int nfs_readpage(struct file *filp, struct page *page)
return ret;
}
-int nfs_readpages(struct file *filp, struct address_space *mapping,
- struct list_head *pages, unsigned nr_pages)
+void nfs_readahead(struct readahead_control *rac)
{
struct nfs_readdesc desc;
- struct inode *inode = mapping->host;
+ struct inode *inode = rac->mapping->host;
+ struct page *page;
int ret;
- dprintk("NFS: nfs_readpages (%s/%Lu %d)\n",
- inode->i_sb->s_id,
- (unsigned long long)NFS_FILEID(inode),
- nr_pages);
+ dprintk("NFS: %s (%s/%llu %lld)\n", __func__,
+ inode->i_sb->s_id,
+ (unsigned long long)NFS_FILEID(inode),
+ readahead_length(rac));
nfs_inc_stats(inode, NFSIOS_VFSREADPAGES);
ret = -ESTALE;
if (NFS_STALE(inode))
- goto out;
+ return;
- if (filp == NULL) {
+ if (rac->file == NULL) {
ret = -EBADF;
desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
if (desc.ctx == NULL)
- goto out;
+ return;
} else
- desc.ctx = get_nfs_open_context(nfs_file_open_context(filp));
+ desc.ctx = get_nfs_open_context(nfs_file_open_context(rac->file));
/* attempt to read as many of the pages as possible from the cache
* - this returns -ENOBUFS immediately if the cookie is negative
*/
- ret = nfs_readpages_from_fscache(desc.ctx, inode, mapping,
- pages, &nr_pages);
+ ret = nfs_readahead_from_fscache(&desc, rac);
if (ret == 0)
goto read_complete; /* all pages were read */
nfs_pageio_init_read(&desc.pgio, inode, false,
&nfs_async_read_completion_ops);
- ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
+ while ((page = readahead_page(rac))) {
+ ret = readpage_async_filler(&desc, page);
+ put_page(page);
+ }
nfs_pageio_complete_read(&desc.pgio, inode);
read_complete:
put_nfs_open_context(desc.ctx);
-out:
- return ret;
}
int __init nfs_init_readpagecache(void)
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 3cfcf219e96b..968c79b1b09b 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -568,8 +568,7 @@ nfs_have_writebacks(struct inode *inode)
* linux/fs/nfs/read.c
*/
extern int nfs_readpage(struct file *, struct page *);
-extern int nfs_readpages(struct file *, struct address_space *,
- struct list_head *, unsigned);
+extern void nfs_readahead(struct readahead_control *rac);
/*
* inline functions
diff --git a/include/linux/nfs_iostat.h b/include/linux/nfs_iostat.h
index 027874c36c88..8baf8fb7551d 100644
--- a/include/linux/nfs_iostat.h
+++ b/include/linux/nfs_iostat.h
@@ -53,7 +53,7 @@
* NFS page counters
*
* These count the number of pages read or written via nfs_readpage(),
- * nfs_readpages(), or their write equivalents.
+ * nfs_readahead(), or their write equivalents.
*
* NB: When adding new byte counters, please include the measured
* units in the name of each byte counter to help users of this
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