Commit 83ae4133 authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba
Browse files

btrfs: add a cached_state to try_lock_extent 



With nowait becoming more pervasive throughout our codebase go ahead and
add a cached_state to try_lock_extent().  This allows us to be faster
about clearing the locked area if we have contention, and then gives us
the same optimization for unlock if we are able to lock the range.

Reviewed-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 76dcd734

fs/btrfs/extent-io-tree.c

+4 −3
Original line number Diff line number Diff line
@@ -1615,17 +1615,18 @@ int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, 
				  changeset);

}



int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)

int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,

		    struct extent_state **cached)

{

	int err;

	u64 failed_start;



	err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, &failed_start,

			       NULL, NULL, GFP_NOFS);

			       cached, NULL, GFP_NOFS);

	if (err == -EEXIST) {

		if (failed_start > start)

			clear_extent_bit(tree, start, failed_start - 1,

					 EXTENT_LOCKED, NULL);

					 EXTENT_LOCKED, cached);

		return 0;

	}

	return 1;

fs/btrfs/extent-io-tree.h

+2 −1
Original line number Diff line number Diff line
@@ -106,7 +106,8 @@ void extent_io_tree_release(struct extent_io_tree *tree); 
int lock_extent(struct extent_io_tree *tree, u64 start, u64 end,

		struct extent_state **cached);



int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end);

int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,

		    struct extent_state **cached);



int __init extent_state_init_cachep(void);

void __cold extent_state_free_cachep(void);

fs/btrfs/extent_io.c

+2 −1
Original line number Diff line number Diff line
@@ -4959,7 +4959,8 @@ static int read_extent_buffer_subpage(struct extent_buffer *eb, int wait, 
	io_tree = &BTRFS_I(fs_info->btree_inode)->io_tree;



	if (wait == WAIT_NONE) {

		if (!try_lock_extent(io_tree, eb->start, eb->start + eb->len - 1))

		if (!try_lock_extent(io_tree, eb->start, eb->start + eb->len - 1,

				     NULL))

			return -EAGAIN;

	} else {

		ret = lock_extent(io_tree, eb->start, eb->start + eb->len - 1, NULL);

fs/btrfs/file.c

+2 −1
Original line number Diff line number Diff line
@@ -1302,7 +1302,8 @@ lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages, 
		struct btrfs_ordered_extent *ordered;



		if (nowait) {

			if (!try_lock_extent(&inode->io_tree, start_pos, last_pos)) {

			if (!try_lock_extent(&inode->io_tree, start_pos, last_pos,

					     cached_state)) {

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

					unlock_page(pages[i]);

					put_page(pages[i]);

fs/btrfs/inode.c

+2 −1
Original line number Diff line number Diff line
@@ -7255,7 +7255,8 @@ static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend, 


	while (1) {

		if (nowait) {

			if (!try_lock_extent(io_tree, lockstart, lockend))

			if (!try_lock_extent(io_tree, lockstart, lockend,

					     cached_state))

				return -EAGAIN;

		} else {

			lock_extent(io_tree, lockstart, lockend, cached_state);