Commit 79f015f2 authored by Goldwyn Rodrigues's avatar Goldwyn Rodrigues Committed by David Sterba
Browse files

btrfs: cleanup extent locking sequence 



Code cleanup for better understanding:
Variable needs_unlock to be called extent_locked to show state as
opposed to action. Changed the type to int, to reduce code in the
critical path.

Signed-off-by: default avatarGoldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 2dbe0c77

fs/btrfs/file.c

+7 −9
Original line number Diff line number Diff line
@@ -1590,7 +1590,6 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file, 
	int ret = 0;

	bool only_release_metadata = false;

	bool force_page_uptodate = false;

	bool need_unlock;



	nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE),

			PAGE_SIZE / (sizeof(struct page *)));
@@ -1613,6 +1612,7 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file, 
		size_t copied;

		size_t dirty_sectors;

		size_t num_sectors;

		int extents_locked;



		WARN_ON(num_pages > nrptrs);
@@ -1669,7 +1669,6 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file, 
		}



		release_bytes = reserve_bytes;

		need_unlock = false;

again:

		/*

		 * This is going to setup the pages array with the number of
@@ -1682,16 +1681,15 @@ again: 
		if (ret)

			break;



		ret = lock_and_cleanup_extent_if_need(BTRFS_I(inode), pages,

		extents_locked = lock_and_cleanup_extent_if_need(

				BTRFS_I(inode), pages,

				num_pages, pos, write_bytes, &lockstart,

				&lockend, &cached_state);

		if (ret < 0) {

			if (ret == -EAGAIN)

		if (extents_locked < 0) {

			if (extents_locked == -EAGAIN)

				goto again;

			ret = extents_locked;

			break;

		} else if (ret > 0) {

			need_unlock = true;

			ret = 0;

		}



		copied = btrfs_copy_from_user(pos, write_bytes, pages, i);
@@ -1756,7 +1754,7 @@ again: 
		if (copied > 0)

			ret = btrfs_dirty_pages(inode, pages, dirty_pages,

						pos, copied, NULL);

		if (need_unlock)

		if (extents_locked)

			unlock_extent_cached(&BTRFS_I(inode)->io_tree,

					     lockstart, lockend, &cached_state,

					     GFP_NOFS);

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