[PATCH] Make address_space_operations->invalidatepage return void

The return value of this function is never used, so let's be honest and
declare it as void.

Some places where invalidatepage returned 0, I have inserted comments
suggesting a BUG_ON.

[akpm@osdl.org: JBD BUG fix]
[akpm@osdl.org: rework for git-nfs]
[akpm@osdl.org: don't go BUG in block_invalidate_page()]
Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

11 files changed, 33 insertions, 38 deletions

diff --git a/fs/afs/file.c b/fs/afs/file.c
index 150b19227922..7bb716887e29 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -28,7 +28,7 @@ static int afs_file_release(struct inode *inode, struct file *file);
 #endif
 
 static int afs_file_readpage(struct file *file, struct page *page);
-static int afs_file_invalidatepage(struct page *page, unsigned long offset);
+static void afs_file_invalidatepage(struct page *page, unsigned long offset);
 static int afs_file_releasepage(struct page *page, gfp_t gfp_flags);
 
 struct inode_operations afs_file_inode_operations = {
@@ -212,7 +212,7 @@ int afs_cache_get_page_cookie(struct page *page,
 /*
  * invalidate part or all of a page
  */
-static int afs_file_invalidatepage(struct page *page, unsigned long offset)
+static void afs_file_invalidatepage(struct page *page, unsigned long offset)
 {
         int ret = 1;
 
@@ -238,11 +238,11 @@ static int afs_file_invalidatepage(struct page *page, unsigned long offset)
                         if (!PageWriteback(page))
                                 ret = page->mapping->a_ops->releasepage(page,
                                                                         0);
+                        /* possibly should BUG_ON(!ret); - neilb */
                 }
         }
 
         _leave(" = %d", ret);
-        return ret;
 } /* end afs_file_invalidatepage() */
 
 /*****************************************************************************/
diff --git a/fs/buffer.c b/fs/buffer.c
index 0b9456fd074f..f25f58096428 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1593,11 +1593,10 @@ EXPORT_SYMBOL(try_to_release_page);
  * point.  Because the caller is about to free (and possibly reuse) those
  * blocks on-disk.
  */
-int block_invalidatepage(struct page *page, unsigned long offset)
+void block_invalidatepage(struct page *page, unsigned long offset)
 {
         struct buffer_head *head, *bh, *next;
         unsigned int curr_off = 0;
-        int ret = 1;
 
         BUG_ON(!PageLocked(page));
         if (!page_has_buffers(page))
@@ -1624,19 +1623,18 @@ int block_invalidatepage(struct page *page, unsigned long offset)
          * so real IO is not possible anymore.
          */
         if (offset == 0)
-                ret = try_to_release_page(page, 0);
+                try_to_release_page(page, 0);
 out:
-        return ret;
+        return;
 }
 EXPORT_SYMBOL(block_invalidatepage);
 
-int do_invalidatepage(struct page *page, unsigned long offset)
+void do_invalidatepage(struct page *page, unsigned long offset)
 {
-        int (*invalidatepage)(struct page *, unsigned long);
-        invalidatepage = page->mapping->a_ops->invalidatepage;
-        if (invalidatepage == NULL)
-                invalidatepage = block_invalidatepage;
-        return (*invalidatepage)(page, offset);
+        void (*invalidatepage)(struct page *, unsigned long);
+        invalidatepage = page->mapping->a_ops->invalidatepage ? :
+                block_invalidatepage;
+        (*invalidatepage)(page, offset);
 }
 
 /*
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index 2c361377e0a5..76e22c9c9c6c 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -1430,7 +1430,7 @@ ext3_readpages(struct file *file, struct address_space *mapping,
         return mpage_readpages(mapping, pages, nr_pages, ext3_get_block);
 }
 
-static int ext3_invalidatepage(struct page *page, unsigned long offset)
+static void ext3_invalidatepage(struct page *page, unsigned long offset)
 {
         journal_t *journal = EXT3_JOURNAL(page->mapping->host);
 
@@ -1440,7 +1440,7 @@ static int ext3_invalidatepage(struct page *page, unsigned long offset)
         if (offset == 0)
                 ClearPageChecked(page);
 
-        return journal_invalidatepage(journal, page, offset);
+        journal_invalidatepage(journal, page, offset);
 }
 
 static int ext3_releasepage(struct page *page, gfp_t wait)
diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c
index ada31fa272e3..c609f5034fcd 100644
--- a/fs/jbd/transaction.c
+++ b/fs/jbd/transaction.c
@@ -1873,16 +1873,15 @@ zap_buffer_unlocked:
 }
 
 /** 
- * int journal_invalidatepage() 
+ * void journal_invalidatepage()
  * @journal: journal to use for flush... 
  * @page:    page to flush
  * @offset:  length of page to invalidate.
  *
  * Reap page buffers containing data after offset in page.
  *
- * Return non-zero if the page's buffers were successfully reaped.
  */
-int journal_invalidatepage(journal_t *journal, 
+void journal_invalidatepage(journal_t *journal,
                       struct page *page, 
                       unsigned long offset)
 {
@@ -1893,7 +1892,7 @@ int journal_invalidatepage(journal_t *journal,
         if (!PageLocked(page))
                 BUG();
         if (!page_has_buffers(page))
-                return 1;
+                return;
 
         /* We will potentially be playing with lists other than just the
          * data lists (especially for journaled data mode), so be
@@ -1916,11 +1915,9 @@ int journal_invalidatepage(journal_t *journal,
         } while (bh != head);
 
         if (!offset) {
-                if (!may_free || !try_to_free_buffers(page))
-                        return 0;
-                J_ASSERT(!page_has_buffers(page));
+                if (may_free && try_to_free_buffers(page))
+                        J_ASSERT(!page_has_buffers(page));
         }
-        return 1;
 }
 
 /* 
diff --git a/fs/jfs/jfs_metapage.c b/fs/jfs/jfs_metapage.c
index 5fbaeaadccd3..8508043849f3 100644
--- a/fs/jfs/jfs_metapage.c
+++ b/fs/jfs/jfs_metapage.c
@@ -578,14 +578,13 @@ static int metapage_releasepage(struct page *page, gfp_t gfp_mask)
         return 0;
 }
 
-static int metapage_invalidatepage(struct page *page, unsigned long offset)
+static void metapage_invalidatepage(struct page *page, unsigned long offset)
 {
         BUG_ON(offset);
 
-        if (PageWriteback(page))
-                return 0;
+        BUG_ON(PageWriteback(page));
 
-        return metapage_releasepage(page, 0);
+        metapage_releasepage(page, 0);
 }
 
 struct address_space_operations jfs_metapage_aops = {
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 5263b2864a44..dee49a0cb995 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -318,10 +318,9 @@ static int nfs_commit_write(struct file *file, struct page *page, unsigned offse
         return status;
 }
 
-static int nfs_invalidate_page(struct page *page, unsigned long offset)
+static void nfs_invalidate_page(struct page *page, unsigned long offset)
 {
         /* FIXME: we really should cancel any unstarted writes on this page */
-        return 1;
 }
 
 static int nfs_release_page(struct page *page, gfp_t gfp)
diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index d60f6238c66a..62e18c19b446 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -2793,7 +2793,7 @@ static int invalidatepage_can_drop(struct inode *inode, struct buffer_head *bh)
 }
 
 /* clm -- taken from fs/buffer.c:block_invalidate_page */
-static int reiserfs_invalidatepage(struct page *page, unsigned long offset)
+static void reiserfs_invalidatepage(struct page *page, unsigned long offset)
 {
         struct buffer_head *head, *bh, *next;
         struct inode *inode = page->mapping->host;
@@ -2832,10 +2832,12 @@ static int reiserfs_invalidatepage(struct page *page, unsigned long offset)
          * The get_block cached value has been unconditionally invalidated,
          * so real IO is not possible anymore.
          */
-        if (!offset && ret)
+        if (!offset && ret) {
                 ret = try_to_release_page(page, 0);
+                /* maybe should BUG_ON(!ret); - neilb */
+        }
       out:
-        return ret;
+        return;
 }
 
 static int reiserfs_set_page_dirty(struct page *page)
diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index 97fc056130eb..4f2476f188b0 100644
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -1442,14 +1442,14 @@ xfs_vm_readpages(
         return mpage_readpages(mapping, pages, nr_pages, xfs_get_block);
 }
 
-STATIC int
+STATIC void
 xfs_vm_invalidatepage(
         struct page             *page,
         unsigned long           offset)
 {
         xfs_page_trace(XFS_INVALIDPAGE_ENTER,
                         page->mapping->host, page, offset);
-        return block_invalidatepage(page, offset);
+        block_invalidatepage(page, offset);
 }
 
 struct address_space_operations xfs_address_space_operations = {
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 27dd97b3fce9..da917ed096a3 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -189,8 +189,8 @@ extern int buffer_heads_over_limit;
  * address_spaces.
  */
 int try_to_release_page(struct page * page, gfp_t gfp_mask);
-int block_invalidatepage(struct page *page, unsigned long offset);
-int do_invalidatepage(struct page *page, unsigned long offset);
+void block_invalidatepage(struct page *page, unsigned long offset);
+void do_invalidatepage(struct page *page, unsigned long offset);
 int block_write_full_page(struct page *page, get_block_t *get_block,
                                 struct writeback_control *wbc);
 int block_read_full_page(struct page*, get_block_t*);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 972435d4df5c..9674679525f9 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -369,7 +369,7 @@ struct address_space_operations {
         int (*commit_write)(struct file *, struct page *, unsigned, unsigned);
         /* Unfortunately this kludge is needed for FIBMAP. Don't use it */
         sector_t (*bmap)(struct address_space *, sector_t);
-        int (*invalidatepage) (struct page *, unsigned long);
+        void (*invalidatepage) (struct page *, unsigned long);
         int (*releasepage) (struct page *, gfp_t);
         ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
                         loff_t offset, unsigned long nr_segs);
diff --git a/include/linux/jbd.h b/include/linux/jbd.h
index 4fc7dffd66ef..6a425e370cb3 100644
--- a/include/linux/jbd.h
+++ b/include/linux/jbd.h
@@ -895,7 +895,7 @@ extern int	 journal_dirty_metadata (handle_t *, struct buffer_head *);
 extern void      journal_release_buffer (handle_t *, struct buffer_head *);
 extern int       journal_forget (handle_t *, struct buffer_head *);
 extern void      journal_sync_buffer (struct buffer_head *);
-extern int       journal_invalidatepage(journal_t *,
+extern void      journal_invalidatepage(journal_t *,
                                 struct page *, unsigned long);
 extern int       journal_try_to_free_buffers(journal_t *, struct page *, gfp_t);
 extern int       journal_stop(handle_t *);