Commit 1d410a6e authored by Mark Fasheh's avatar Mark Fasheh
Browse files

ocfs2: Small refactor of truncate zeroing code 



We'll want to reuse most of this when pushing inline data back out to an
extent. Keeping this part as a seperate patch helps to keep the upcoming
changes for write support uncluttered.

The core portion of ocfs2_zero_cluster_pages() responsible for making sure a
page is mapped and properly dirtied is abstracted out into it's own
function, ocfs2_map_and_dirty_page(). Actual functionality doesn't change,
though zeroing becomes optional.

We also turn part of ocfs2_free_write_ctxt() into  a common function for
unlocking and freeing a page array. This operation is very common (and
uniform) for Ocfs2 cluster sizes greater than page size, so it makes sense
to keep the code in one place.

Signed-off-by: default avatarMark Fasheh <mark.fasheh@oracle.com>
Reviewed-by: default avatarJoel Becker <joel.becker@oracle.com>
parent 65ed39d6

fs/ocfs2/alloc.c

+72 −79
Original line number Diff line number Diff line
@@ -5633,39 +5633,18 @@ static int ocfs2_ordered_zero_func(handle_t *handle, struct buffer_head *bh) 
	return ocfs2_journal_dirty_data(handle, bh);

}



static void ocfs2_zero_cluster_pages(struct inode *inode, loff_t start,

				     loff_t end, struct page **pages,

				     int numpages, u64 phys, handle_t *handle)

static void ocfs2_map_and_dirty_page(struct inode *inode, handle_t *handle,

				     unsigned int from, unsigned int to,

				     struct page *page, int zero, u64 *phys)

{

	int i, ret, partial = 0;

	void *kaddr;

	struct page *page;

	unsigned int from, to = PAGE_CACHE_SIZE;

	struct super_block *sb = inode->i_sb;



	BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(sb)));



	if (numpages == 0)

		goto out;



	to = PAGE_CACHE_SIZE;

	for(i = 0; i < numpages; i++) {

		page = pages[i];



		from = start & (PAGE_CACHE_SIZE - 1);

		if ((end >> PAGE_CACHE_SHIFT) == page->index)

			to = end & (PAGE_CACHE_SIZE - 1);



		BUG_ON(from > PAGE_CACHE_SIZE);

		BUG_ON(to > PAGE_CACHE_SIZE);

	int ret, partial = 0;



		ret = ocfs2_map_page_blocks(page, &phys, inode, from, to, 0);

	ret = ocfs2_map_page_blocks(page, phys, inode, from, to, 0);

	if (ret)

		mlog_errno(ret);



		kaddr = kmap_atomic(page, KM_USER0);

		memset(kaddr + from, 0, to - from);

		kunmap_atomic(kaddr, KM_USER0);

	if (zero)

		zero_user_page(page, from, to - from, KM_USER0);



	/*

	 * Need to set the buffers we zero'd into uptodate
@@ -5691,55 +5670,58 @@ static void ocfs2_zero_cluster_pages(struct inode *inode, loff_t start, 
		SetPageUptodate(page);



	flush_dcache_page(page);



		start = (page->index + 1) << PAGE_CACHE_SHIFT;

}

out:

	if (pages) {



static void ocfs2_zero_cluster_pages(struct inode *inode, loff_t start,

				     loff_t end, struct page **pages,

				     int numpages, u64 phys, handle_t *handle)

{

	int i;

	struct page *page;

	unsigned int from, to = PAGE_CACHE_SIZE;

	struct super_block *sb = inode->i_sb;



	BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(sb)));



	if (numpages == 0)

		goto out;



	to = PAGE_CACHE_SIZE;

	for(i = 0; i < numpages; i++) {

		page = pages[i];

			unlock_page(page);

			mark_page_accessed(page);

			page_cache_release(page);

		}



		from = start & (PAGE_CACHE_SIZE - 1);

		if ((end >> PAGE_CACHE_SHIFT) == page->index)

			to = end & (PAGE_CACHE_SIZE - 1);



		BUG_ON(from > PAGE_CACHE_SIZE);

		BUG_ON(to > PAGE_CACHE_SIZE);



		ocfs2_map_and_dirty_page(inode, handle, from, to, page, 1,

					 &phys);



		start = (page->index + 1) << PAGE_CACHE_SHIFT;

	}

out:

	if (pages)

		ocfs2_unlock_and_free_pages(pages, numpages);

}



static int ocfs2_grab_eof_pages(struct inode *inode, loff_t start, loff_t end,

				struct page **pages, int *num, u64 *phys)

				struct page **pages, int *num)

{

	int i, numpages = 0, ret = 0;

	unsigned int ext_flags;

	int numpages, ret = 0;

	struct super_block *sb = inode->i_sb;

	struct address_space *mapping = inode->i_mapping;

	unsigned long index;

	loff_t last_page_bytes;



	BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(sb)));

	BUG_ON(start > end);



	if (start == end)

		goto out;



	BUG_ON(start >> OCFS2_SB(sb)->s_clustersize_bits !=

	       (end - 1) >> OCFS2_SB(sb)->s_clustersize_bits);



	ret = ocfs2_extent_map_get_blocks(inode, start >> sb->s_blocksize_bits,

					  phys, NULL, &ext_flags);

	if (ret) {

		mlog_errno(ret);

		goto out;

	}



	/* Tail is a hole. */

	if (*phys == 0)

		goto out;



	/* Tail is marked as unwritten, we can count on write to zero

	 * in that case. */

	if (ext_flags & OCFS2_EXT_UNWRITTEN)

		goto out;



	numpages = 0;

	last_page_bytes = PAGE_ALIGN(end);

	index = start >> PAGE_CACHE_SHIFT;

	do {
@@ -5756,14 +5738,8 @@ static int ocfs2_grab_eof_pages(struct inode *inode, loff_t start, loff_t end, 


out:

	if (ret != 0) {

		if (pages) {

			for (i = 0; i < numpages; i++) {

				if (pages[i]) {

					unlock_page(pages[i]);

					page_cache_release(pages[i]);

				}

			}

		}

		if (pages)

			ocfs2_unlock_and_free_pages(pages, numpages);

		numpages = 0;

	}
@@ -5784,18 +5760,20 @@ out: 
int ocfs2_zero_range_for_truncate(struct inode *inode, handle_t *handle,

				  u64 range_start, u64 range_end)

{

	int ret, numpages;

	int ret = 0, numpages;

	struct page **pages = NULL;

	u64 phys;

	unsigned int ext_flags;

	struct super_block *sb = inode->i_sb;



	/*

	 * File systems which don't support sparse files zero on every

	 * extend.

	 */

	if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))

	if (!ocfs2_sparse_alloc(OCFS2_SB(sb)))

		return 0;



	pages = kcalloc(ocfs2_pages_per_cluster(inode->i_sb),

	pages = kcalloc(ocfs2_pages_per_cluster(sb),

			sizeof(struct page *), GFP_NOFS);

	if (pages == NULL) {

		ret = -ENOMEM;
@@ -5803,15 +5781,30 @@ int ocfs2_zero_range_for_truncate(struct inode *inode, handle_t *handle, 
		goto out;

	}



	ret = ocfs2_grab_eof_pages(inode, range_start, range_end, pages,

				   &numpages, &phys);

	if (range_start == range_end)

		goto out;



	ret = ocfs2_extent_map_get_blocks(inode,

					  range_start >> sb->s_blocksize_bits,

					  &phys, NULL, &ext_flags);

	if (ret) {

		mlog_errno(ret);

		goto out;

	}



	if (numpages == 0)

	/*

	 * Tail is a hole, or is marked unwritten. In either case, we

	 * can count on read and write to return/push zero's.

	 */

	if (phys == 0 || ext_flags & OCFS2_EXT_UNWRITTEN)

		goto out;



	ret = ocfs2_grab_eof_pages(inode, range_start, range_end, pages,

				   &numpages);

	if (ret) {

		mlog_errno(ret);

		goto out;

	}



	ocfs2_zero_cluster_pages(inode, range_start, range_end, pages,

				 numpages, phys, handle);

fs/ocfs2/aops.c

+12 −8
Original line number Diff line number Diff line
@@ -830,18 +830,22 @@ struct ocfs2_write_ctxt { 
	struct ocfs2_cached_dealloc_ctxt w_dealloc;

};



static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc)

void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages)

{

	int i;



	for(i = 0; i < wc->w_num_pages; i++) {

		if (wc->w_pages[i] == NULL)

			continue;



		unlock_page(wc->w_pages[i]);

		mark_page_accessed(wc->w_pages[i]);

		page_cache_release(wc->w_pages[i]);

	for(i = 0; i < num_pages; i++) {

		if (pages[i]) {

			unlock_page(pages[i]);

			mark_page_accessed(pages[i]);

			page_cache_release(pages[i]);

		}

	}

}



static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc)

{

	ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages);



	brelse(wc->w_di_bh);

	kfree(wc);

fs/ocfs2/aops.h

+2 −0
Original line number Diff line number Diff line
@@ -34,6 +34,8 @@ int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno, 
			  struct inode *inode, unsigned int from,

			  unsigned int to, int new);



void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages);



int walk_page_buffers(	handle_t *handle,

			struct buffer_head *head,

			unsigned from,

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