nfs: convert to new aops

[akpm@linux-foundation.org: fix against git-nfs] [peterz@infradead.org: fix against git-nfs] Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nfs: convert to new aops
[akpm@linux-foundation.org: fix against git-nfs] [peterz@infradead.org: fix against git-nfs] Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nick Piggin · Linus Torvalds
1 parent a20fa20c54
Showing 1 changed file with 60 additions and 20 deletions Side-by-side Diff
fs/nfs/file.c
@@ -306,27 +306,50 @@
 }
  
 /*
- * This does the "real" work of the write. The generic routine has
- * allocated the page, locked it, done all the page alignment stuff
- * calculations etc. Now we should just copy the data from user
- * space and write it back to the real medium..
+ * 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
+ * data from user space.
  *
  * If the writer ends up delaying the write, the writer needs to
  * increment the page use counts until he is done with the page.
  */
-static int nfs_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to)
+static int nfs_write_begin(struct file *file, struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned flags,
+			struct page **pagep, void **fsdata)
 {
-	return nfs_flush_incompatible(file, page);
+	int ret;
+	pgoff_t index;
+	struct page *page;
+	index = pos >> PAGE_CACHE_SHIFT;
+
+	page = __grab_cache_page(mapping, index);
+	if (!page)
+		return -ENOMEM;
+	*pagep = page;
+
+	ret = nfs_flush_incompatible(file, page);
+	if (ret) {
+		unlock_page(page);
+		page_cache_release(page);
+	}
+	return ret;
 }
  
-static int nfs_commit_write(struct file *file, struct page *page, unsigned offset, unsigned to)
+static int nfs_write_end(struct file *file, struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned copied,
+			struct page *page, void *fsdata)
 {
-	long status;
+	unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
+	int status;
  
 	lock_kernel();
-	status = nfs_updatepage(file, page, offset, to-offset);
+	status = nfs_updatepage(file, page, offset, copied);
 	unlock_kernel();
-	return status;
+
+	unlock_page(page);
+	page_cache_release(page);
+
+	return status < 0 ? status : copied;
 }
  
 static void nfs_invalidate_page(struct page *page, unsigned long offset)
@@ -354,8 +377,8 @@
 	.set_page_dirty = __set_page_dirty_nobuffers,
 	.writepage = nfs_writepage,
 	.writepages = nfs_writepages,
-	.prepare_write = nfs_prepare_write,
-	.commit_write = nfs_commit_write,
+	.write_begin = nfs_write_begin,
+	.write_end = nfs_write_end,
 	.invalidatepage = nfs_invalidate_page,
 	.releasepage = nfs_release_page,
 #ifdef CONFIG_NFS_DIRECTIO
  
  
  
@@ -369,18 +392,35 @@
 	struct file *filp = vma->vm_file;
 	unsigned pagelen;
 	int ret = -EINVAL;
+	void *fsdata;
+	struct address_space *mapping;
+	loff_t offset;
  
 	lock_page(page);
-	if (page->mapping != vma->vm_file->f_path.dentry->d_inode->i_mapping)
-		goto out_unlock;
+	mapping = page->mapping;
+	if (mapping != vma->vm_file->f_path.dentry->d_inode->i_mapping) {
+		unlock_page(page);
+		return -EINVAL;
+	}
 	pagelen = nfs_page_length(page);
-	if (pagelen == 0)
-		goto out_unlock;
-	ret = nfs_prepare_write(filp, page, 0, pagelen);
-	if (!ret)
-		ret = nfs_commit_write(filp, page, 0, pagelen);
-out_unlock:
+	offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
 	unlock_page(page);
+
+	/*
+	 * we can use mapping after releasing the page lock, because:
+	 * we hold mmap_sem on the fault path, which should pin the vma
+	 * which should pin the file, which pins the dentry which should
+	 * hold a reference on inode.
+	 */
+
+	if (pagelen) {
+		struct page *page2 = NULL;
+		ret = nfs_write_begin(filp, mapping, offset, pagelen,
+			       	0, &page2, &fsdata);
+		if (!ret)
+			ret = nfs_write_end(filp, mapping, offset, pagelen,
+				       	pagelen, page2, fsdata);
+	}
 	return ret;
 }
...	...	@@ -306,27 +306,50 @@
306	306	}
307	307
308	308	/*
309		- * This does the "real" work of the write. The generic routine has
310		- * allocated the page, locked it, done all the page alignment stuff
311		- * calculations etc. Now we should just copy the data from user
312		- * space and write it back to the real medium..
	309	+ * This does the "real" work of the write. We must allocate and lock the
	310	+ * page to be sent back to the generic routine, which then copies the
	311	+ * data from user space.
313	312	*
314	313	* If the writer ends up delaying the write, the writer needs to
315	314	* increment the page use counts until he is done with the page.
316	315	*/
317		-static int nfs_prepare_write(struct file file, struct page page, unsigned offset, unsigned to)
	316	+static int nfs_write_begin(struct file file, struct address_space mapping,
	317	+ loff_t pos, unsigned len, unsigned flags,
	318	+ struct page pagep, void fsdata)
318	319	{
319		- return nfs_flush_incompatible(file, page);
	320	+ int ret;
	321	+ pgoff_t index;
	322	+ struct page *page;
	323	+ index = pos >> PAGE_CACHE_SHIFT;
	324	+
	325	+ page = __grab_cache_page(mapping, index);
	326	+ if (!page)
	327	+ return -ENOMEM;
	328	+ *pagep = page;
	329	+
	330	+ ret = nfs_flush_incompatible(file, page);
	331	+ if (ret) {
	332	+ unlock_page(page);
	333	+ page_cache_release(page);
	334	+ }
	335	+ return ret;
320	336	}
321	337
322		-static int nfs_commit_write(struct file file, struct page page, unsigned offset, unsigned to)
	338	+static int nfs_write_end(struct file file, struct address_space mapping,
	339	+ loff_t pos, unsigned len, unsigned copied,
	340	+ struct page page, void fsdata)
323	341	{
324		- long status;
	342	+ unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
	343	+ int status;
325	344
326	345	lock_kernel();
327		- status = nfs_updatepage(file, page, offset, to-offset);
	346	+ status = nfs_updatepage(file, page, offset, copied);
328	347	unlock_kernel();
329		- return status;
	348	+
	349	+ unlock_page(page);
	350	+ page_cache_release(page);
	351	+
	352	+ return status < 0 ? status : copied;
330	353	}
331	354
332	355	static void nfs_invalidate_page(struct page *page, unsigned long offset)
...	...	@@ -354,8 +377,8 @@
354	377	.set_page_dirty = __set_page_dirty_nobuffers,
355	378	.writepage = nfs_writepage,
356	379	.writepages = nfs_writepages,
357		- .prepare_write = nfs_prepare_write,
358		- .commit_write = nfs_commit_write,
	380	+ .write_begin = nfs_write_begin,
	381	+ .write_end = nfs_write_end,
359	382	.invalidatepage = nfs_invalidate_page,
360	383	.releasepage = nfs_release_page,
361	384	#ifdef CONFIG_NFS_DIRECTIO
362	385
363	386
364	387
...	...	@@ -369,18 +392,35 @@
369	392	struct file *filp = vma->vm_file;
370	393	unsigned pagelen;
371	394	int ret = -EINVAL;
	395	+ void *fsdata;
	396	+ struct address_space *mapping;
	397	+ loff_t offset;
372	398
373	399	lock_page(page);
374		- if (page->mapping != vma->vm_file->f_path.dentry->d_inode->i_mapping)
375		- goto out_unlock;
	400	+ mapping = page->mapping;
	401	+ if (mapping != vma->vm_file->f_path.dentry->d_inode->i_mapping) {
	402	+ unlock_page(page);
	403	+ return -EINVAL;
	404	+ }
376	405	pagelen = nfs_page_length(page);
377		- if (pagelen == 0)
378		- goto out_unlock;
379		- ret = nfs_prepare_write(filp, page, 0, pagelen);
380		- if (!ret)
381		- ret = nfs_commit_write(filp, page, 0, pagelen);
382		-out_unlock:
	406	+ offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
383	407	unlock_page(page);
	408	+
	409	+ /*
	410	+ * we can use mapping after releasing the page lock, because:
	411	+ * we hold mmap_sem on the fault path, which should pin the vma
	412	+ * which should pin the file, which pins the dentry which should
	413	+ * hold a reference on inode.
	414	+ */
	415	+
	416	+ if (pagelen) {
	417	+ struct page *page2 = NULL;
	418	+ ret = nfs_write_begin(filp, mapping, offset, pagelen,
	419	+ 0, &page2, &fsdata);
	420	+ if (!ret)
	421	+ ret = nfs_write_end(filp, mapping, offset, pagelen,
	422	+ pagelen, page2, fsdata);
	423	+ }
384	424	return ret;
385	425	}
386	426