2008-02-22 20:36:55

by Mingming Cao

[permalink] [raw]
Subject: [PATCH]ext4: use write_begin/write_end in delalloc instead of prepare_write()

Since generally the current mainline VFS API changed to use write-begin()
and write_end(), updating ext4 delayed allocation to adopt this change.

Signed-off-by: Mingming Cao <[email protected]>
---
fs/ext4/inode.c | 36 ++++++++++++++++++++++++++----------
1 file changed, 26 insertions(+), 10 deletions(-)

Index: linux-2.6.25-rc2/fs/ext4/inode.c
===================================================================
--- linux-2.6.25-rc2.orig/fs/ext4/inode.c 2008-02-21 17:30:59.000000000 -0800
+++ linux-2.6.25-rc2/fs/ext4/inode.c 2008-02-22 12:17:16.000000000 -0800
@@ -1421,13 +1421,6 @@ static int ext4_da_get_block_prep(struct
return ret;
}

-
-static int ext4_da_prepare_write(struct file *file, struct page *page,
- unsigned from, unsigned to)
-{
- return block_prepare_write(page, from, to, ext4_da_get_block_prep);
-}
-
static int ext4_da_get_block_write(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
@@ -1485,11 +1478,34 @@ out:
}

static int ext4_da_writepages(struct address_space *mapping,
- struct writeback_control *wbc)
+ struct writeback_control *wbc)
{
return mpage_da_writepages(mapping, wbc, ext4_da_get_block_write);
}

+static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ int ret;
+ struct page *page;
+ pgoff_t index;
+ unsigned from, to;
+
+ index = pos >> PAGE_CACHE_SHIFT;
+ from = pos & (PAGE_CACHE_SIZE - 1);
+ to = from + len;
+
+ page = __grab_cache_page(mapping, index);
+ if (!page)
+ return -ENOMEM;
+ *pagep = page;
+
+ ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+ ext4_da_get_block_prep);
+ return ret;
+}
+
static void ext4_da_invalidatepage(struct page *page, unsigned long offset)
{
struct buffer_head *head, *bh;
@@ -1990,8 +2006,8 @@ static const struct address_space_operat
.writepage = ext4_writeback_writepage,
.writepages = ext4_da_writepages,
.sync_page = block_sync_page,
- .prepare_write = ext4_da_prepare_write,
- .commit_write = generic_commit_write,
+ .write_begin = ext4_da_write_begin,
+ .write_end = generic_write_end,
.bmap = ext4_bmap,
.invalidatepage = ext4_da_invalidatepage,
.releasepage = ext4_releasepage,