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Btrfs: Add writepages support
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Signed-off-by: Chris Mason <chris.mason@oracle.com>
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@chrismason-xx
chrismason-xx committed Sep 25, 2008
1 parent 944746e commit b293f02
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Showing 3 changed files with 124 additions and 25 deletions.
135 changes: 110 additions & 25 deletions fs/btrfs/extent_map.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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 */
Expand All @@ -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",
Expand Down Expand Up @@ -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)) {
Expand Down Expand Up @@ -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);
Expand All @@ -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;
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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);
Expand All @@ -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
Expand Down Expand Up @@ -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;
Expand Down
4 changes: 4 additions & 0 deletions fs/btrfs/extent_map.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down
10 changes: 10 additions & 0 deletions fs/btrfs/inode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -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,
Expand Down

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