Btrfs: Add writepages support
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index ff8881f..b0677c8 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -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 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",
@@ -1460,37 +1467,73 @@
#endif
}
+static struct bio *
+extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
+ gfp_t gfp_flags)
+{
+ struct bio *bio;
+
+ bio = bio_alloc(gfp_flags, nr_vecs);
+
+ if (bio == NULL && (current->flags & PF_MEMALLOC)) {
+ while (!bio && (nr_vecs /= 2))
+ bio = bio_alloc(gfp_flags, nr_vecs);
+ }
+
+ 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)
{
- struct bio *bio;
int ret = 0;
+ struct bio *bio;
+ int nr;
- bio = bio_alloc(GFP_NOIO, 1);
-
- 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_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);
+ }
- bio_get(bio);
- submit_bio(rw, bio);
-
- if (bio_flagged(bio, BIO_EOPNOTSUPP))
- ret = -EOPNOTSUPP;
-
- bio_put(bio);
return ret;
}
@@ -1590,7 +1633,8 @@
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 @@
* 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 @@
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 @@
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 @@
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 @@
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;