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authorChris Mason <chris.mason@oracle.com>2007-11-08 10:59:22 -0500
committerChris Mason <chris.mason@oracle.com>2008-09-25 11:03:57 -0400
commit3ab2fb5a8cb003897016b6eb38ddad916226c1b2 (patch)
treedce5ac7ae586111c7e872193c09ced717b936549 /fs/btrfs/extent_map.c
parent856bf3e592f917e7d663cb7fa93e83fe795e8f4e (diff)
Btrfs: Add readpages support
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/extent_map.c')
-rw-r--r--fs/btrfs/extent_map.c70
1 files changed, 63 insertions, 7 deletions
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 754bc42c162..0077c6c1d9f 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -11,6 +11,7 @@
#include <linux/swap.h>
#include <linux/version.h>
#include <linux/writeback.h>
+#include <linux/pagevec.h>
#include "extent_map.h"
/* temporary define until extent_map moves out of btrfs */
@@ -1503,7 +1504,7 @@ static int submit_extent_page(int rw, struct extent_map_tree *tree,
size_t size, unsigned long offset,
struct block_device *bdev,
struct bio **bio_ret,
- int max_pages,
+ unsigned long max_pages,
bio_end_io_t end_io_func)
{
int ret = 0;
@@ -1520,7 +1521,7 @@ static int submit_extent_page(int rw, struct extent_map_tree *tree,
return 0;
}
}
- nr = min(max_pages, bio_get_nr_vecs(bdev));
+ nr = min_t(int, 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);
@@ -1552,8 +1553,10 @@ void set_page_extent_mapped(struct page *page)
* into the tree that are removed when the IO is done (by the end_io
* handlers)
*/
-int extent_read_full_page(struct extent_map_tree *tree, struct page *page,
- get_extent_t *get_extent)
+static int __extent_read_full_page(struct extent_map_tree *tree,
+ struct page *page,
+ get_extent_t *get_extent,
+ struct bio **bio)
{
struct inode *inode = page->mapping->host;
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
@@ -1631,10 +1634,12 @@ int extent_read_full_page(struct extent_map_tree *tree, struct page *page,
cur + iosize - 1);
}
if (!ret) {
+ unsigned long nr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
+ nr -= page->index;
ret = submit_extent_page(READ, tree, page,
- sector, iosize, page_offset,
- bdev, NULL, 1,
- end_bio_extent_readpage);
+ sector, iosize, page_offset,
+ bdev, bio, nr,
+ end_bio_extent_readpage);
}
if (ret)
SetPageError(page);
@@ -1649,6 +1654,18 @@ int extent_read_full_page(struct extent_map_tree *tree, struct page *page,
}
return 0;
}
+
+int extent_read_full_page(struct extent_map_tree *tree, struct page *page,
+ get_extent_t *get_extent)
+{
+ struct bio *bio = NULL;
+ int ret;
+
+ ret = __extent_read_full_page(tree, page, get_extent, &bio);
+ if (bio)
+ submit_one_bio(READ, bio);
+ return ret;
+}
EXPORT_SYMBOL(extent_read_full_page);
/*
@@ -1836,6 +1853,45 @@ int extent_writepages(struct extent_map_tree *tree,
}
EXPORT_SYMBOL(extent_writepages);
+int extent_readpages(struct extent_map_tree *tree,
+ struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages,
+ get_extent_t get_extent)
+{
+ struct bio *bio = NULL;
+ unsigned page_idx;
+ struct pagevec pvec;
+
+ pagevec_init(&pvec, 0);
+ for (page_idx = 0; page_idx < nr_pages; page_idx++) {
+ struct page *page = list_entry(pages->prev, struct page, lru);
+
+ prefetchw(&page->flags);
+ list_del(&page->lru);
+ /*
+ * what we want to do here is call add_to_page_cache_lru,
+ * but that isn't exported, so we reproduce it here
+ */
+ if (!add_to_page_cache(page, mapping,
+ page->index, GFP_KERNEL)) {
+
+ /* open coding of lru_cache_add, also not exported */
+ page_cache_get(page);
+ if (!pagevec_add(&pvec, page))
+ __pagevec_lru_add(&pvec);
+ __extent_read_full_page(tree, page, get_extent, &bio);
+ }
+ page_cache_release(page);
+ }
+ if (pagevec_count(&pvec))
+ __pagevec_lru_add(&pvec);
+ BUG_ON(!list_empty(pages));
+ if (bio)
+ submit_one_bio(READ, bio);
+ return 0;
+}
+EXPORT_SYMBOL(extent_readpages);
+
/*
* basic invalidatepage code, this waits on any locked or writeback
* ranges corresponding to the page, and then deletes any extent state