Btrfs: delay clearing EXTENT_DELALLOC for compressed extents (a3429ab7) · Commits · 戴 / test

When compression is on, the cow_file_range code is farmed off to worker threads. This allows us to do significant CPU work in parallel on SMP machines. But it is a delicate balance around when we clear flags and how. In the past we cleared the delalloc flag immediately, which was safe because the pages stayed locked. But this is causing problems with the newest ENOSPC code, and with the recent extent state cleanups we can now clear the delalloc bit at the same time the uncompressed code does. Signed-off-by:

Chris Mason <chris.mason@oracle.com>

fs/btrfs/inode.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -427,6 +427,7 @@ again:
		&BTRFS_I(inode)->io_tree,
		start, end, NULL,
		EXTENT_CLEAR_UNLOCK_PAGE \| EXTENT_CLEAR_DIRTY \|
		EXTENT_CLEAR_DELALLOC \|
		EXTENT_SET_WRITEBACK \| EXTENT_END_WRITEBACK);
		ret = 0;
		goto free_pages_out;
		@@ -644,6 +645,7 @@ static noinline int submit_compressed_extents(struct inode *inode,
		async_extent->ram_size - 1,
		NULL, EXTENT_CLEAR_UNLOCK_PAGE \|
		EXTENT_CLEAR_UNLOCK \|
		EXTENT_CLEAR_DELALLOC \|
		EXTENT_CLEAR_DIRTY \| EXTENT_SET_WRITEBACK);

		ret = btrfs_submit_compressed_write(inode,
		@@ -877,8 +879,8 @@ static int cow_file_range_async(struct inode inode, struct page locked_page,
		u64 cur_end;
		int limit = 10 * 1024 * 1042;

		clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED \|
		EXTENT_DELALLOC, 1, 0, NULL, GFP_NOFS);
		clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
		1, 0, NULL, GFP_NOFS);
		while (start < end) {
		async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
		async_cow->inode = inode;

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