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Commit 0ee53206 authored by Benjamin Marzinski's avatar Benjamin Marzinski Committed by Steven Whitehouse
Browse files

GFS2: directly write blocks past i_size 



GFS2 was relying on the writepage code to write out the zeroed data for
fallocate.  However, with FALLOC_FL_KEEP_SIZE set, this may be past i_size.
If it is, it will be ignored.  To work around this, gfs2 now calls
write_dirty_buffer directly on the buffer_heads when FALLOC_FL_KEEP_SIZE
is set, and it's writing past i_size.

This version is just a cleanup of my last version

Signed-off-by: default avatarBenjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent deab72d3

fs/gfs2/file.c

+48 −10
Original line number Diff line number Diff line
@@ -617,18 +617,51 @@ static ssize_t gfs2_file_aio_write(struct kiocb *iocb, const struct iovec *iov, 
	return generic_file_aio_write(iocb, iov, nr_segs, pos);

}



static void empty_write_end(struct page *page, unsigned from,

			   unsigned to)

static int empty_write_end(struct page *page, unsigned from,

			   unsigned to, int mode)

{

	struct gfs2_inode *ip = GFS2_I(page->mapping->host);

	struct inode *inode = page->mapping->host;

	struct gfs2_inode *ip = GFS2_I(inode);

	struct buffer_head *bh;

	unsigned offset, blksize = 1 << inode->i_blkbits;

	pgoff_t end_index = i_size_read(inode) >> PAGE_CACHE_SHIFT;



	zero_user(page, from, to-from);

	mark_page_accessed(page);



	if (page->index < end_index || !(mode & FALLOC_FL_KEEP_SIZE)) {

		if (!gfs2_is_writeback(ip))

			gfs2_page_add_databufs(ip, page, from, to);



		block_commit_write(page, from, to);

		return 0;

	}



	offset = 0;

	bh = page_buffers(page);

	while (offset < to) {

		if (offset >= from) {

			set_buffer_uptodate(bh);

			mark_buffer_dirty(bh);

			clear_buffer_new(bh);

			write_dirty_buffer(bh, WRITE);

		}

		offset += blksize;

		bh = bh->b_this_page;

	}



	offset = 0;

	bh = page_buffers(page);

	while (offset < to) {

		if (offset >= from) {

			wait_on_buffer(bh);

			if (!buffer_uptodate(bh))

				return -EIO;

		}

		offset += blksize;

		bh = bh->b_this_page;

	}

	return 0;

}



static int needs_empty_write(sector_t block, struct inode *inode)
@@ -643,7 +676,8 @@ static int needs_empty_write(sector_t block, struct inode *inode) 
	return !buffer_mapped(&bh_map);

}



static int write_empty_blocks(struct page *page, unsigned from, unsigned to)

static int write_empty_blocks(struct page *page, unsigned from, unsigned to,

			      int mode)

{

	struct inode *inode = page->mapping->host;

	unsigned start, end, next, blksize;
@@ -668,7 +702,9 @@ static int write_empty_blocks(struct page *page, unsigned from, unsigned to) 
							  gfs2_block_map);

				if (unlikely(ret))

					return ret;

				empty_write_end(page, start, end);

				ret = empty_write_end(page, start, end, mode);

				if (unlikely(ret))

					return ret;

				end = 0;

			}

			start = next;
@@ -682,7 +718,9 @@ static int write_empty_blocks(struct page *page, unsigned from, unsigned to) 
		ret = __block_write_begin(page, start, end - start, gfs2_block_map);

		if (unlikely(ret))

			return ret;

		empty_write_end(page, start, end);

		ret = empty_write_end(page, start, end, mode);

		if (unlikely(ret))

			return ret;

	}



	return 0;
@@ -731,7 +769,7 @@ static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len, 


		if (curr == end)

			to = end_offset;

		error = write_empty_blocks(page, from, to);

		error = write_empty_blocks(page, from, to, mode);

		if (!error && offset + to > inode->i_size &&

		    !(mode & FALLOC_FL_KEEP_SIZE)) {

			i_size_write(inode, offset + to);