Commit b293f02e authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: Add writepages support 



Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 944746ec

fs/btrfs/extent_map.c

+110 −25
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include <linux/blkdev.h>

#include <linux/swap.h>

#include <linux/version.h>

#include <linux/writeback.h>

#include "extent_map.h"



/* temporary define until extent_map moves out of btrfs */
@@ -35,6 +36,12 @@ struct tree_entry { 
	struct rb_node rb_node;

};



struct extent_page_data {

	struct bio *bio;

	struct extent_map_tree *tree;

	get_extent_t *get_extent;

};



void __init extent_map_init(void)

{

	extent_map_cache = btrfs_cache_create("extent_map",
@@ -1460,40 +1467,76 @@ static int end_bio_extent_preparewrite(struct bio *bio, 
#endif

}



static int submit_extent_page(int rw, struct extent_map_tree *tree,

			      struct page *page, sector_t sector,

			      size_t size, unsigned long offset,

			      struct block_device *bdev,

			      bio_end_io_t end_io_func)

static struct bio *

extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,

		 gfp_t gfp_flags)

{

	struct bio *bio;

	int ret = 0;



	bio = bio_alloc(GFP_NOIO, 1);

	bio = bio_alloc(gfp_flags, nr_vecs);



	bio->bi_sector = sector;

	bio->bi_bdev = bdev;

	bio->bi_io_vec[0].bv_page = page;

	bio->bi_io_vec[0].bv_len = size;

	bio->bi_io_vec[0].bv_offset = offset;



	bio->bi_vcnt = 1;

	bio->bi_idx = 0;

	bio->bi_size = size;

	if (bio == NULL && (current->flags & PF_MEMALLOC)) {

		while (!bio && (nr_vecs /= 2))

			bio = bio_alloc(gfp_flags, nr_vecs);

	}



	bio->bi_end_io = end_io_func;

	bio->bi_private = tree;

	if (bio) {

		bio->bi_bdev = bdev;

		bio->bi_sector = first_sector;

	}

	return bio;

}



static int submit_one_bio(int rw, struct bio *bio)

{

	int ret = 0;

	bio_get(bio);

	submit_bio(rw, bio);



	if (bio_flagged(bio, BIO_EOPNOTSUPP))

		ret = -EOPNOTSUPP;



	bio_put(bio);

	return ret;

}



static int submit_extent_page(int rw, struct extent_map_tree *tree,

			      struct page *page, sector_t sector,

			      size_t size, unsigned long offset,

			      struct block_device *bdev,

			      struct bio **bio_ret,

			      int max_pages,

			      bio_end_io_t end_io_func)

{

	int ret = 0;

	struct bio *bio;

	int nr;



	if (bio_ret && *bio_ret) {

		bio = *bio_ret;

		if (bio->bi_sector + (bio->bi_size >> 9) != sector ||

		    bio_add_page(bio, page, size, offset) < size) {

			ret = submit_one_bio(rw, bio);

			bio = NULL;

		} else {

			return 0;

		}

	}

	nr = min(max_pages, bio_get_nr_vecs(bdev));

	bio = extent_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);

	if (!bio) {

		printk("failed to allocate bio nr %d\n", nr);

	}

	bio_add_page(bio, page, size, offset);

	bio->bi_end_io = end_io_func;

	bio->bi_private = tree;

	if (bio_ret) {

		*bio_ret = bio;

	} else {

		ret = submit_one_bio(rw, bio);

	}



	return ret;

}



void set_page_extent_mapped(struct page *page)

{

	if (!PagePrivate(page)) {
@@ -1590,7 +1633,8 @@ int extent_read_full_page(struct extent_map_tree *tree, struct page *page, 
		if (!ret) {

			ret = submit_extent_page(READ, tree, page,

						 sector, iosize, page_offset,

						 bdev, end_bio_extent_readpage);

						 bdev, NULL, 1,

						 end_bio_extent_readpage);

		}

		if (ret)

			SetPageError(page);
@@ -1613,11 +1657,12 @@ EXPORT_SYMBOL(extent_read_full_page); 
 * are found, they are marked writeback.  Then the lock bits are removed

 * and the end_io handler clears the writeback ranges

 */

int extent_write_full_page(struct extent_map_tree *tree, struct page *page,

			  get_extent_t *get_extent,

			  struct writeback_control *wbc)

static int __extent_writepage(struct page *page, struct writeback_control *wbc,

			      void *data)

{

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

	struct extent_page_data *epd = data;

	struct extent_map_tree *tree = epd->tree;

	u64 start = (u64)page->index << PAGE_CACHE_SHIFT;

	u64 page_end = start + PAGE_CACHE_SIZE - 1;

	u64 end;
@@ -1691,7 +1736,7 @@ int extent_write_full_page(struct extent_map_tree *tree, struct page *page, 
			clear_extent_dirty(tree, cur, page_end, GFP_NOFS);

			break;

		}

		em = get_extent(inode, page, page_offset, cur, end, 1);

		em = epd->get_extent(inode, page, page_offset, cur, end, 1);

		if (IS_ERR(em) || !em) {

			SetPageError(page);

			break;
@@ -1734,9 +1779,12 @@ int extent_write_full_page(struct extent_map_tree *tree, struct page *page, 
		if (ret)

			SetPageError(page);

		else {

			unsigned long nr = end_index + 1;

			set_range_writeback(tree, cur, cur + iosize - 1);



			ret = submit_extent_page(WRITE, tree, page, sector,

						 iosize, page_offset, bdev,

						 &epd->bio, nr,

						 end_bio_extent_writepage);

			if (ret)

				SetPageError(page);
@@ -1750,8 +1798,44 @@ int extent_write_full_page(struct extent_map_tree *tree, struct page *page, 
	unlock_page(page);

	return 0;

}



int extent_write_full_page(struct extent_map_tree *tree, struct page *page,

			  get_extent_t *get_extent,

			  struct writeback_control *wbc)

{

	int ret;

	struct extent_page_data epd = {

		.bio = NULL,

		.tree = tree,

		.get_extent = get_extent,

	};



	ret = __extent_writepage(page, wbc, &epd);

	if (epd.bio)

		submit_one_bio(WRITE, epd.bio);

	return ret;

}

EXPORT_SYMBOL(extent_write_full_page);



int extent_writepages(struct extent_map_tree *tree,

		      struct address_space *mapping,

		      get_extent_t *get_extent,

		      struct writeback_control *wbc)

{

	int ret;

	struct extent_page_data epd = {

		.bio = NULL,

		.tree = tree,

		.get_extent = get_extent,

	};



	ret = write_cache_pages(mapping, wbc, __extent_writepage, &epd);

	if (epd.bio)

		submit_one_bio(WRITE, epd.bio);

	return ret;

}

EXPORT_SYMBOL(extent_writepages);



/*

 * basic invalidatepage code, this waits on any locked or writeback

 * ranges corresponding to the page, and then deletes any extent state
@@ -1869,6 +1953,7 @@ int extent_prepare_write(struct extent_map_tree *tree, 
				       EXTENT_LOCKED, 0, NULL, GFP_NOFS);

			ret = submit_extent_page(READ, tree, page,

					 sector, iosize, page_offset, em->bdev,

					 NULL, 1,

					 end_bio_extent_preparewrite);

			iocount++;

			block_start = block_start + iosize;

fs/btrfs/extent_map.h

+4 −0
Original line number Diff line number Diff line
@@ -136,6 +136,10 @@ int extent_invalidatepage(struct extent_map_tree *tree, 
int extent_write_full_page(struct extent_map_tree *tree, struct page *page,

			  get_extent_t *get_extent,

			  struct writeback_control *wbc);

int extent_writepages(struct extent_map_tree *tree,

		      struct address_space *mapping,

		      get_extent_t *get_extent,

		      struct writeback_control *wbc);

int extent_prepare_write(struct extent_map_tree *tree,

			 struct inode *inode, struct page *page,

			 unsigned from, unsigned to, get_extent_t *get_extent);

fs/btrfs/inode.c

+10 −0
Original line number Diff line number Diff line
@@ -1747,6 +1747,15 @@ static int btrfs_writepage(struct page *page, struct writeback_control *wbc) 
	return extent_write_full_page(tree, page, btrfs_get_extent, wbc);

}





static int btrfs_writepages(struct address_space *mapping,

			    struct writeback_control *wbc)

{

	struct extent_map_tree *tree;

	tree = &BTRFS_I(mapping->host)->extent_tree;

	return extent_writepages(tree, mapping, btrfs_get_extent, wbc);

}



static int btrfs_releasepage(struct page *page, gfp_t unused_gfp_flags)

{

	struct extent_map_tree *tree;
@@ -2526,6 +2535,7 @@ static struct extent_map_ops btrfs_extent_map_ops = { 
static struct address_space_operations btrfs_aops = {

	.readpage	= btrfs_readpage,

	.writepage	= btrfs_writepage,

	.writepages	= btrfs_writepages,

	.sync_page	= block_sync_page,

	.prepare_write	= btrfs_prepare_write,

	.commit_write	= btrfs_commit_write,