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authorDavid Howells <dhowells@redhat.com>2006-08-29 19:05:54 +0100
committerJens Axboe <axboe@nelson.home.kernel.dk>2006-09-30 20:31:19 +0200
commitcf9a2ae8d49948f861b56e5333530e491a9da190 (patch)
tree21f0b0d781b3e60cc60464d39b6d95681201b37e /mm/truncate.c
parent4090959aee403817ff386415f9bc602c1a0882ef (diff)
downloadlwn-cf9a2ae8d49948f861b56e5333530e491a9da190.tar.gz
lwn-cf9a2ae8d49948f861b56e5333530e491a9da190.zip
[PATCH] BLOCK: Move functions out of buffer code [try #6]
Move some functions out of the buffering code that aren't strictly buffering specific. This is a precursor to being able to disable the block layer. (*) Moved some stuff out of fs/buffer.c: (*) The file sync and general sync stuff moved to fs/sync.c. (*) The superblock sync stuff moved to fs/super.c. (*) do_invalidatepage() moved to mm/truncate.c. (*) try_to_release_page() moved to mm/filemap.c. (*) Moved some related declarations between header files: (*) declarations for do_invalidatepage() and try_to_release_page() moved to linux/mm.h. (*) __set_page_dirty_buffers() moved to linux/buffer_head.h. Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'mm/truncate.c')
-rw-r--r--mm/truncate.c24
1 files changed, 24 insertions, 0 deletions
diff --git a/mm/truncate.c b/mm/truncate.c
index a654928323dc..cd3e34b816db 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -17,6 +17,30 @@
do_invalidatepage */
+/**
+ * do_invalidatepage - invalidate part of all of a page
+ * @page: the page which is affected
+ * @offset: the index of the truncation point
+ *
+ * do_invalidatepage() is called when all or part of the page has become
+ * invalidated by a truncate operation.
+ *
+ * do_invalidatepage() does not have to release all buffers, but it must
+ * ensure that no dirty buffer is left outside @offset and that no I/O
+ * is underway against any of the blocks which are outside the truncation
+ * point. Because the caller is about to free (and possibly reuse) those
+ * blocks on-disk.
+ */
+void do_invalidatepage(struct page *page, unsigned long offset)
+{
+ void (*invalidatepage)(struct page *, unsigned long);
+ invalidatepage = page->mapping->a_ops->invalidatepage;
+ if (!invalidatepage)
+ invalidatepage = block_invalidatepage;
+ if (invalidatepage)
+ (*invalidatepage)(page, offset);
+}
+
static inline void truncate_partial_page(struct page *page, unsigned partial)
{
memclear_highpage_flush(page, partial, PAGE_CACHE_SIZE-partial);