tunnels: fix netns vs proto registration ordering
[safe/jmp/linux-2.6] / fs / afs / file.c
index 9c0e721..39b3016 100644 (file)
@@ -23,6 +23,9 @@ static void afs_invalidatepage(struct page *page, unsigned long offset);
 static int afs_releasepage(struct page *page, gfp_t gfp_flags);
 static int afs_launder_page(struct page *page);
 
+static int afs_readpages(struct file *filp, struct address_space *mapping,
+                        struct list_head *pages, unsigned nr_pages);
+
 const struct file_operations afs_file_operations = {
        .open           = afs_open,
        .release        = afs_release,
@@ -32,8 +35,10 @@ const struct file_operations afs_file_operations = {
        .aio_read       = generic_file_aio_read,
        .aio_write      = afs_file_write,
        .mmap           = generic_file_readonly_mmap,
-       .sendfile       = generic_file_sendfile,
+       .splice_read    = generic_file_splice_read,
        .fsync          = afs_fsync,
+       .lock           = afs_lock,
+       .flock          = afs_flock,
 };
 
 const struct inode_operations afs_file_inode_operations = {
@@ -44,12 +49,13 @@ const struct inode_operations afs_file_inode_operations = {
 
 const struct address_space_operations afs_fs_aops = {
        .readpage       = afs_readpage,
+       .readpages      = afs_readpages,
        .set_page_dirty = afs_set_page_dirty,
        .launder_page   = afs_launder_page,
        .releasepage    = afs_releasepage,
        .invalidatepage = afs_invalidatepage,
-       .prepare_write  = afs_prepare_write,
-       .commit_write   = afs_commit_write,
+       .write_begin    = afs_write_begin,
+       .write_end      = afs_write_end,
        .writepage      = afs_writepage,
        .writepages     = afs_writepages,
 };
@@ -96,38 +102,21 @@ int afs_release(struct inode *inode, struct file *file)
        return 0;
 }
 
+#ifdef CONFIG_AFS_FSCACHE
 /*
  * deal with notification that a page was read from the cache
  */
-#ifdef AFS_CACHING_SUPPORT
-static void afs_readpage_read_complete(void *cookie_data,
-                                      struct page *page,
-                                      void *data,
-                                      int error)
+static void afs_file_readpage_read_complete(struct page *page,
+                                           void *data,
+                                           int error)
 {
-       _enter("%p,%p,%p,%d", cookie_data, page, data, error);
+       _enter("%p,%p,%d", page, data, error);
 
-       if (error)
-               SetPageError(page);
-       else
+       /* if the read completes with an error, we just unlock the page and let
+        * the VM reissue the readpage */
+       if (!error)
                SetPageUptodate(page);
        unlock_page(page);
-
-}
-#endif
-
-/*
- * deal with notification that a page was written to the cache
- */
-#ifdef AFS_CACHING_SUPPORT
-static void afs_readpage_write_complete(void *cookie_data,
-                                       struct page *page,
-                                       void *data,
-                                       int error)
-{
-       _enter("%p,%p,%p,%d", cookie_data, page, data, error);
-
-       unlock_page(page);
 }
 #endif
 
@@ -145,9 +134,16 @@ static int afs_readpage(struct file *file, struct page *page)
 
        inode = page->mapping->host;
 
-       ASSERT(file != NULL);
-       key = file->private_data;
-       ASSERT(key != NULL);
+       if (file) {
+               key = file->private_data;
+               ASSERT(key != NULL);
+       } else {
+               key = afs_request_key(AFS_FS_S(inode->i_sb)->volume->cell);
+               if (IS_ERR(key)) {
+                       ret = PTR_ERR(key);
+                       goto error_nokey;
+               }
+       }
 
        _enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index);
 
@@ -159,9 +155,9 @@ static int afs_readpage(struct file *file, struct page *page)
        if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
                goto error;
 
-#ifdef AFS_CACHING_SUPPORT
        /* is it cached? */
-       ret = cachefs_read_or_alloc_page(vnode->cache,
+#ifdef CONFIG_AFS_FSCACHE
+       ret = fscache_read_or_alloc_page(vnode->cache,
                                         page,
                                         afs_file_readpage_read_complete,
                                         NULL,
@@ -169,20 +165,21 @@ static int afs_readpage(struct file *file, struct page *page)
 #else
        ret = -ENOBUFS;
 #endif
-
        switch (ret) {
-               /* read BIO submitted and wb-journal entry found */
-       case 1:
-               BUG(); // TODO - handle wb-journal match
-
                /* read BIO submitted (page in cache) */
        case 0:
                break;
 
-               /* no page available in cache */
-       case -ENOBUFS:
+               /* page not yet cached */
        case -ENODATA:
+               _debug("cache said ENODATA");
+               goto go_on;
+
+               /* page will not be cached */
+       case -ENOBUFS:
+               _debug("cache said ENOBUFS");
        default:
+       go_on:
                offset = page->index << PAGE_CACHE_SHIFT;
                len = min_t(size_t, i_size_read(inode) - offset, PAGE_SIZE);
 
@@ -196,68 +193,96 @@ static int afs_readpage(struct file *file, struct page *page)
                                set_bit(AFS_VNODE_DELETED, &vnode->flags);
                                ret = -ESTALE;
                        }
-#ifdef AFS_CACHING_SUPPORT
-                       cachefs_uncache_page(vnode->cache, page);
+
+#ifdef CONFIG_AFS_FSCACHE
+                       fscache_uncache_page(vnode->cache, page);
 #endif
+                       BUG_ON(PageFsCache(page));
                        goto error;
                }
 
                SetPageUptodate(page);
 
-#ifdef AFS_CACHING_SUPPORT
-               if (cachefs_write_page(vnode->cache,
-                                      page,
-                                      afs_file_readpage_write_complete,
-                                      NULL,
-                                      GFP_KERNEL) != 0
-                   ) {
-                       cachefs_uncache_page(vnode->cache, page);
-                       unlock_page(page);
+               /* send the page to the cache */
+#ifdef CONFIG_AFS_FSCACHE
+               if (PageFsCache(page) &&
+                   fscache_write_page(vnode->cache, page, GFP_KERNEL) != 0) {
+                       fscache_uncache_page(vnode->cache, page);
+                       BUG_ON(PageFsCache(page));
                }
-#else
-               unlock_page(page);
 #endif
+               unlock_page(page);
        }
 
+       if (!file)
+               key_put(key);
        _leave(" = 0");
        return 0;
 
 error:
        SetPageError(page);
        unlock_page(page);
+       if (!file)
+               key_put(key);
+error_nokey:
        _leave(" = %d", ret);
        return ret;
 }
 
 /*
- * invalidate part or all of a page
+ * read a set of pages
  */
-static void afs_invalidatepage(struct page *page, unsigned long offset)
+static int afs_readpages(struct file *file, struct address_space *mapping,
+                        struct list_head *pages, unsigned nr_pages)
 {
-       int ret = 1;
+       struct afs_vnode *vnode;
+       int ret = 0;
 
-       _enter("{%lu},%lu", page->index, offset);
+       _enter(",{%lu},,%d", mapping->host->i_ino, nr_pages);
 
-       BUG_ON(!PageLocked(page));
+       vnode = AFS_FS_I(mapping->host);
+       if (vnode->flags & AFS_VNODE_DELETED) {
+               _leave(" = -ESTALE");
+               return -ESTALE;
+       }
 
-       if (PagePrivate(page)) {
-               /* We release buffers only if the entire page is being
-                * invalidated.
-                * The get_block cached value has been unconditionally
-                * invalidated, so real IO is not possible anymore.
-                */
-               if (offset == 0) {
-                       BUG_ON(!PageLocked(page));
-
-                       ret = 0;
-                       if (!PageWriteback(page))
-                               ret = page->mapping->a_ops->releasepage(page,
-                                                                       0);
-                       /* possibly should BUG_ON(!ret); - neilb */
-               }
+       /* attempt to read as many of the pages as possible */
+#ifdef CONFIG_AFS_FSCACHE
+       ret = fscache_read_or_alloc_pages(vnode->cache,
+                                         mapping,
+                                         pages,
+                                         &nr_pages,
+                                         afs_file_readpage_read_complete,
+                                         NULL,
+                                         mapping_gfp_mask(mapping));
+#else
+       ret = -ENOBUFS;
+#endif
+
+       switch (ret) {
+               /* all pages are being read from the cache */
+       case 0:
+               BUG_ON(!list_empty(pages));
+               BUG_ON(nr_pages != 0);
+               _leave(" = 0 [reading all]");
+               return 0;
+
+               /* there were pages that couldn't be read from the cache */
+       case -ENODATA:
+       case -ENOBUFS:
+               break;
+
+               /* other error */
+       default:
+               _leave(" = %d", ret);
+               return ret;
        }
 
-       _leave(" = %d", ret);
+       /* load the missing pages from the network */
+       ret = read_cache_pages(mapping, pages, (void *) afs_readpage, file);
+
+       _leave(" = %d [netting]", ret);
+       return ret;
 }
 
 /*
@@ -271,25 +296,73 @@ static int afs_launder_page(struct page *page)
 }
 
 /*
- * release a page and cleanup its private data
+ * invalidate part or all of a page
+ * - release a page and clean up its private data if offset is 0 (indicating
+ *   the entire page)
+ */
+static void afs_invalidatepage(struct page *page, unsigned long offset)
+{
+       struct afs_writeback *wb = (struct afs_writeback *) page_private(page);
+
+       _enter("{%lu},%lu", page->index, offset);
+
+       BUG_ON(!PageLocked(page));
+
+       /* we clean up only if the entire page is being invalidated */
+       if (offset == 0) {
+#ifdef CONFIG_AFS_FSCACHE
+               if (PageFsCache(page)) {
+                       struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
+                       fscache_wait_on_page_write(vnode->cache, page);
+                       fscache_uncache_page(vnode->cache, page);
+               }
+#endif
+
+               if (PagePrivate(page)) {
+                       if (wb && !PageWriteback(page)) {
+                               set_page_private(page, 0);
+                               afs_put_writeback(wb);
+                       }
+
+                       if (!page_private(page))
+                               ClearPagePrivate(page);
+               }
+       }
+
+       _leave("");
+}
+
+/*
+ * release a page and clean up its private state if it's not busy
+ * - return true if the page can now be released, false if not
  */
 static int afs_releasepage(struct page *page, gfp_t gfp_flags)
 {
+       struct afs_writeback *wb = (struct afs_writeback *) page_private(page);
        struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
-       struct afs_writeback *wb;
 
        _enter("{{%x:%u}[%lu],%lx},%x",
               vnode->fid.vid, vnode->fid.vnode, page->index, page->flags,
               gfp_flags);
 
+       /* deny if page is being written to the cache and the caller hasn't
+        * elected to wait */
+#ifdef CONFIG_AFS_FSCACHE
+       if (!fscache_maybe_release_page(vnode->cache, page, gfp_flags)) {
+               _leave(" = F [cache busy]");
+               return 0;
+       }
+#endif
+
        if (PagePrivate(page)) {
-               wb = (struct afs_writeback *) page_private(page);
-               ASSERT(wb != NULL);
-               set_page_private(page, 0);
+               if (wb) {
+                       set_page_private(page, 0);
+                       afs_put_writeback(wb);
+               }
                ClearPagePrivate(page);
-               afs_put_writeback(wb);
        }
 
-       _leave(" = 0");
-       return 0;
+       /* indicate that the page can be released */
+       _leave(" = T");
+       return 1;
 }