NFS: Convert nfs_write_begin/end to use folios

Add a helper nfs_folio_grab_cache_write_begin() that can call
__filemap_get_folio() directly with the appropriate parameters.

Since write_begin()/write_end() take struct page arguments, just pass
the folio->page back for now.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 9fbe27214da0981c14c293d7793564e15203461f..39ee7fb3f79f548d9f3643acd9dbe2118c2ed6db 100644 (file)
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -276,27 +276,28 @@ EXPORT_SYMBOL_GPL(nfs_file_fsync);
  * and that the new data won't completely replace the old data in
  * that range of the file.
  */
-static bool nfs_full_page_write(struct page *page, loff_t pos, unsigned int len)
+static bool nfs_folio_is_full_write(struct folio *folio, loff_t pos,
+                                   unsigned int len)
 {
-       unsigned int pglen = nfs_page_length(page);
-       unsigned int offset = pos & (PAGE_SIZE - 1);
+       unsigned int pglen = nfs_folio_length(folio);
+       unsigned int offset = offset_in_folio(folio, pos);
        unsigned int end = offset + len;
 
        return !pglen || (end >= pglen && !offset);
 }
 
-static bool nfs_want_read_modify_write(struct file *file, struct page *page,
-                       loff_t pos, unsigned int len)
+static bool nfs_want_read_modify_write(struct file *file, struct folio *folio,
+                                      loff_t pos, unsigned int len)
 {
        /*
         * Up-to-date pages, those with ongoing or full-page write
         * don't need read/modify/write
         */
-       if (PageUptodate(page) || PagePrivate(page) ||
-           nfs_full_page_write(page, pos, len))
+       if (folio_test_uptodate(folio) || folio_test_private(folio) ||
+           nfs_folio_is_full_write(folio, pos, len))
                return false;
 
-       if (pnfs_ld_read_whole_page(file->f_mapping->host))
+       if (pnfs_ld_read_whole_page(file_inode(file)))
                return true;
        /* Open for reading too? */
        if (file->f_mode & FMODE_READ)
@@ -304,6 +305,15 @@ static bool nfs_want_read_modify_write(struct file *file, struct page *page,
        return false;
 }
 
+static struct folio *
+nfs_folio_grab_cache_write_begin(struct address_space *mapping, pgoff_t index)
+{
+       unsigned fgp_flags = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE;
+
+       return __filemap_get_folio(mapping, index, fgp_flags,
+                                  mapping_gfp_mask(mapping));
+}
+
 /*
  * This does the "real" work of the write. We must allocate and lock the
  * page to be sent back to the generic routine, which then copies the
@@ -313,34 +323,31 @@ static bool nfs_want_read_modify_write(struct file *file, struct page *page,
  * increment the page use counts until he is done with the page.
  */
 static int nfs_write_begin(struct file *file, struct address_space *mapping,
-                       loff_t pos, unsigned len,
-                       struct page **pagep, void **fsdata)
+                          loff_t pos, unsigned len, struct page **pagep,
+                          void **fsdata)
 {
-       int ret;
-       pgoff_t index = pos >> PAGE_SHIFT;
-       struct page *page;
        struct folio *folio;
        int once_thru = 0;
+       int ret;
 
        dfprintk(PAGECACHE, "NFS: write_begin(%pD2(%lu), %u@%lld)\n",
                file, mapping->host->i_ino, len, (long long) pos);
 
 start:
-       page = grab_cache_page_write_begin(mapping, index);
-       if (!page)
+       folio = nfs_folio_grab_cache_write_begin(mapping, pos >> PAGE_SHIFT);
+       if (!folio)
                return -ENOMEM;
-       *pagep = page;
-       folio = page_folio(page);
+       *pagep = &folio->page;
 
        ret = nfs_flush_incompatible(file, folio);
        if (ret) {
-               unlock_page(page);
-               put_page(page);
+               folio_unlock(folio);
+               folio_put(folio);
        } else if (!once_thru &&
-                  nfs_want_read_modify_write(file, page, pos, len)) {
+                  nfs_want_read_modify_write(file, folio, pos, len)) {
                once_thru = 1;
                ret = nfs_read_folio(file, folio);
-               put_page(page);
+               folio_put(folio);
                if (!ret)
                        goto start;
        }
@@ -348,12 +355,12 @@ start:
 }
 
 static int nfs_write_end(struct file *file, struct address_space *mapping,
-                       loff_t pos, unsigned len, unsigned copied,
-                       struct page *page, void *fsdata)
+                        loff_t pos, unsigned len, unsigned copied,
+                        struct page *page, void *fsdata)
 {
-       unsigned offset = pos & (PAGE_SIZE - 1);
        struct nfs_open_context *ctx = nfs_file_open_context(file);
        struct folio *folio = page_folio(page);
+       unsigned offset = offset_in_folio(folio, pos);
        int status;
 
        dfprintk(PAGECACHE, "NFS: write_end(%pD2(%lu), %u@%lld)\n",
@@ -363,26 +370,26 @@ static int nfs_write_end(struct file *file, struct address_space *mapping,
         * Zero any uninitialised parts of the page, and then mark the page
         * as up to date if it turns out that we're extending the file.
         */
-       if (!PageUptodate(page)) {
-               unsigned pglen = nfs_page_length(page);
+       if (!folio_test_uptodate(folio)) {
+               size_t fsize = folio_size(folio);
+               unsigned pglen = nfs_folio_length(folio);
                unsigned end = offset + copied;
 
                if (pglen == 0) {
-                       zero_user_segments(page, 0, offset,
-                                       end, PAGE_SIZE);
-                       SetPageUptodate(page);
+                       folio_zero_segments(folio, 0, offset, end, fsize);
+                       folio_mark_uptodate(folio);
                } else if (end >= pglen) {
-                       zero_user_segment(page, end, PAGE_SIZE);
+                       folio_zero_segment(folio, end, fsize);
                        if (offset == 0)
-                               SetPageUptodate(page);
+                               folio_mark_uptodate(folio);
                } else
-                       zero_user_segment(page, pglen, PAGE_SIZE);
+                       folio_zero_segment(folio, pglen, fsize);
        }
 
        status = nfs_update_folio(file, folio, offset, copied);
 
-       unlock_page(page);
-       put_page(page);
+       folio_unlock(folio);
+       folio_put(folio);
 
        if (status < 0)
                return status;