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Pass IO size to batch_write() address space operation

PATCH New Badari Pulavarty 1 participant 1 message Jul 24, 2006 1 message not in the archive

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A message that is not in the archive (sent off-list or not yet received): [email protected]

Badari Pulavarty

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PATCH 1/1 Pass IO size to batch_write() address space operation

Hi,

Here is the patch to pass size of the remaining IO to batch_write() interface. I would like to use it ext3/ext4 to allocate in chunks. Currently its passing only the size of the current buffer (in the vector entry).

Comments ? Flames ? Looks reasonable ?

Thanks,
Badari

Pass remaining size of this IO to batch_write(). This way filesystems could choose to allocate for the entire IO, instead of current buffer size.

I would like to use this for setting ext3 reservation window or allocating entire extent (ext4).

Signed-off-by Badari Pulavarty <[email protected]>
---
 include/linux/fs.h |    2 ++
 mm/filemap.c       |    1 +
 2 files changed, 3 insertions(+)
include/linux/fs.h +2 -0
Index: linux-2.6.18-rc1/include/linux/fs.h
===================================================================
@@ -356,6 +356,7 @@ struct writeback_control;
  * struct write_descriptor - set of write arguments
  * @pos: offset from the start of the file to write to
  * @count: number of bytes to write
+ * @iosize: remaining number of bytes in the IO
  * @buf: pointer to data to be written
  * @lru_pvec: multipage container to batch adding pages to LRU list
  * @cached_page: allocated but not used on previous call

@@ -366,6 +367,7 @@ struct writeback_control;
 struct write_descriptor {
 	loff_t pos;
 	size_t count;
+	size_t iosize;
 	char __user *buf;
 	struct page *cached_page;
 	struct pagevec *lru_pvec;
mm/filemap.c +1 -0
Index: linux-2.6.18-rc1/mm/filemap.c
===================================================================
@@ -2278,6 +2278,7 @@ generic_file_buffered_write(struct kiocb
 	do {
 		/* do not walk over current segment */
 		desc.buf = cur_iov->iov_base + iov_base;
+		desc.iosize = count;
 		desc.count = min(count, cur_iov->iov_len - iov_base);
 		if (desc.count > 0)
 			status = (*batch_write)(file, &desc, &copied);