Btrfs: use percpu counter for fs_info->delalloc_bytes

fs_info->delalloc_bytes is accessed very frequently, so use percpu
counter instead of the u64 variant for it to reduce the lock
contention.

This patch also fixed the problem that we access the variant
without the lock protection.At worst, we would not flush the
delalloc inodes, and just return ENOSPC error when we still have
some free space in the fs.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
This commit is contained in:
Miao Xie
2013-01-29 10:10:51 +00:00
committed by Josef Bacik
parent e2d845211e
commit 963d678b0f
4 changed files with 26 additions and 11 deletions

View File

@@ -2010,10 +2010,16 @@ int open_ctree(struct super_block *sb,
fs_info->dirty_metadata_batch = PAGE_CACHE_SIZE *
(1 + ilog2(nr_cpu_ids));
ret = percpu_counter_init(&fs_info->delalloc_bytes, 0);
if (ret) {
err = ret;
goto fail_dirty_metadata_bytes;
}
fs_info->btree_inode = new_inode(sb);
if (!fs_info->btree_inode) {
err = -ENOMEM;
goto fail_dirty_metadata_bytes;
goto fail_delalloc_bytes;
}
mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
@@ -2269,6 +2275,7 @@ int open_ctree(struct super_block *sb,
sectorsize = btrfs_super_sectorsize(disk_super);
stripesize = btrfs_super_stripesize(disk_super);
fs_info->dirty_metadata_batch = leafsize * (1 + ilog2(nr_cpu_ids));
fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
/*
* mixed block groups end up with duplicate but slightly offset
@@ -2731,6 +2738,8 @@ fail_iput:
invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
iput(fs_info->btree_inode);
fail_delalloc_bytes:
percpu_counter_destroy(&fs_info->delalloc_bytes);
fail_dirty_metadata_bytes:
percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
fail_bdi:
@@ -3362,9 +3371,9 @@ int close_ctree(struct btrfs_root *root)
btrfs_free_qgroup_config(root->fs_info);
if (fs_info->delalloc_bytes) {
printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
(unsigned long long)fs_info->delalloc_bytes);
if (percpu_counter_sum(&fs_info->delalloc_bytes)) {
printk(KERN_INFO "btrfs: at unmount delalloc count %lld\n",
percpu_counter_sum(&fs_info->delalloc_bytes));
}
free_extent_buffer(fs_info->extent_root->node);
@@ -3412,6 +3421,7 @@ int close_ctree(struct btrfs_root *root)
btrfs_mapping_tree_free(&fs_info->mapping_tree);
percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
percpu_counter_destroy(&fs_info->delalloc_bytes);
bdi_destroy(&fs_info->bdi);
cleanup_srcu_struct(&fs_info->subvol_srcu);