Commit 14048ed0 authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: Cache extent buffer mappings 



Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent db94535d

fs/btrfs/ctree.h

+36 −4
Original line number Diff line number Diff line
@@ -436,10 +436,18 @@ static inline u##bits btrfs_##name(struct extent_buffer *eb, \ 
	unsigned long map_len;						\

	unsigned long offset = (unsigned long)s +			\

				offsetof(type, member);			\

	if (eb->map_token && offset >= eb->map_start &&			\

	    offset + sizeof(((type *)0)->member) <= eb->map_start +	\

	    eb->map_len) {						\

	    kaddr = eb->kaddr;						\

	    map_start = eb->map_start;					\

	    err = 0;							\

	} else {							\

		err = map_extent_buffer(eb, offset,			\

			        sizeof(((type *)0)->member),		\

				&map_token, &kaddr,			\

				&map_start, &map_len, KM_USER1);	\

	}								\

	if (!err) {							\

		__le##bits *tmp = (__le##bits *)(kaddr + offset -	\

					       map_start);		\
@@ -464,10 +472,18 @@ static inline void btrfs_set_##name(struct extent_buffer *eb, \ 
	int unmap_on_exit = (eb->map_token == NULL);			\

	unsigned long offset = (unsigned long)s +			\

				offsetof(type, member);			\

	if (eb->map_token && offset >= eb->map_start &&			\

	    offset + sizeof(((type *)0)->member) <= eb->map_start +	\

	    eb->map_len) {						\

	    kaddr = eb->kaddr;						\

	    map_start = eb->map_start;					\

	    err = 0;							\

	} else {							\

		err = map_extent_buffer(eb, offset,			\

			        sizeof(((type *)0)->member),		\

				&map_token, &kaddr,			\

				&map_start, &map_len, KM_USER1);	\

	}								\

	if (!err) {							\

		__le##bits *tmp = (__le##bits *)(kaddr + offset -	\

					       map_start);		\
@@ -490,10 +506,18 @@ static inline u##bits btrfs_##name(struct extent_buffer *eb) \ 
	unsigned long map_len;						\

	unsigned long offset = offsetof(type, member);			\

	int unmap_on_exit = (eb->map_token == NULL);			\

	if (eb->map_token && offset >= eb->map_start &&			\

	    offset + sizeof(((type *)0)->member) <= eb->map_start +	\

	    eb->map_len) {						\

	    kaddr = eb->kaddr;						\

	    map_start = eb->map_start;					\

	    err = 0;							\

	} else {							\

		err = map_extent_buffer(eb, offset,			\

			        sizeof(((type *)0)->member),		\

				&map_token, &kaddr,			\

				&map_start, &map_len, KM_USER1);	\

	}								\

	if (!err) {							\

		__le##bits *tmp = (__le##bits *)(kaddr + offset -	\

					       map_start);		\
@@ -517,10 +541,18 @@ static inline void btrfs_set_##name(struct extent_buffer *eb, \ 
	unsigned long map_len;						\

	unsigned long offset = offsetof(type, member);			\

	int unmap_on_exit = (eb->map_token == NULL);			\

	if (eb->map_token && offset >= eb->map_start &&			\

	    offset + sizeof(((type *)0)->member) <= eb->map_start +	\

	    eb->map_len) {						\

	    kaddr = eb->kaddr;						\

	    map_start = eb->map_start;					\

	    err = 0;							\

	} else {							\

		err = map_extent_buffer(eb, offset,			\

			        sizeof(((type *)0)->member),		\

				&map_token, &kaddr,			\

				&map_start, &map_len, KM_USER1);	\

	}								\

	if (!err) {							\

		__le##bits *tmp = (__le##bits *)(kaddr + offset -	\

					       map_start);		\

fs/btrfs/extent_map.c

+13 −2
Original line number Diff line number Diff line
@@ -2037,6 +2037,7 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, 
	struct extent_buffer *eb;

	struct page *p;

	struct address_space *mapping = tree->mapping;

	int uptodate = 1;



	eb = __alloc_extent_buffer(mask);

	if (!eb || IS_ERR(eb))
@@ -2048,7 +2049,7 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, 
	atomic_set(&eb->refs, 1);



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

		p = find_get_page(mapping, index);

		p = find_lock_page(mapping, index);

		if (!p) {

			/* make sure the free only frees the pages we've

			 * grabbed a reference on
@@ -2060,7 +2061,12 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, 
		set_page_extent_mapped(p);

		if (i == 0)

			eb->first_page = p;

		if (!PageUptodate(p))

			uptodate = 0;

		unlock_page(p);

	}

	if (uptodate)

		eb->flags |= EXTENT_UPTODATE;

	return eb;

fail:

	free_extent_buffer(eb);
@@ -2192,7 +2198,7 @@ int read_extent_buffer_pages(struct extent_map_tree *tree, 
	if (eb->flags & EXTENT_UPTODATE)

		return 0;



	if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,

	if (0 && test_range_bit(tree, eb->start, eb->start + eb->len - 1,

			   EXTENT_UPTODATE, 1)) {

		return 0;

	}
@@ -2247,6 +2253,7 @@ void read_extent_buffer(struct extent_buffer *eb, void *dstv, 
	char *dst = (char *)dstv;

	size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);

	unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;

	unsigned long num_pages = num_extent_pages(eb->start, eb->len);



	WARN_ON(start > eb->len);

	WARN_ON(start + len > eb->start + eb->len);
@@ -2257,6 +2264,10 @@ void read_extent_buffer(struct extent_buffer *eb, void *dstv, 


	while(len > 0) {

		page = extent_buffer_page(eb, i);

		if (!PageUptodate(page)) {

			printk("page %lu not up to date i %lu, total %lu, len %lu\n", page->index, i, num_pages, eb->len);

			WARN_ON(1);

		}

		WARN_ON(!PageUptodate(page));



		cur = min(len, (PAGE_CACHE_SIZE - offset));