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Commit df0af1a5 authored by Miao Xie's avatar Miao Xie Committed by Josef Bacik
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Btrfs: use the inode own lock to protect its delalloc_bytes 



We need not use a global lock to protect the delalloc_bytes of the
inode, just use its own lock. In this way, we can reduce the lock
contention and ->delalloc_lock will just protect delalloc inode
list.

Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: default avatarJosef Bacik <jbacik@fusionio.com>
parent 963d678b

fs/btrfs/btrfs_inode.h

+1 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ 
#define BTRFS_INODE_HAS_ASYNC_EXTENT		6

#define BTRFS_INODE_NEEDS_FULL_SYNC		7

#define BTRFS_INODE_COPY_EVERYTHING		8

#define BTRFS_INODE_IN_DELALLOC_LIST		9



/* in memory btrfs inode */

struct btrfs_inode {

fs/btrfs/disk-io.c

+2 −0
Original line number Diff line number Diff line
@@ -3690,6 +3690,8 @@ static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root) 
				    delalloc_inodes);



		list_del_init(&btrfs_inode->delalloc_inodes);

		clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,

			  &btrfs_inode->runtime_flags);



		btrfs_invalidate_inodes(btrfs_inode->root);

	}

fs/btrfs/inode.c

+34 −13
Original line number Diff line number Diff line
@@ -1514,16 +1514,23 @@ static void btrfs_set_bit_hook(struct inode *inode, 
			spin_unlock(&BTRFS_I(inode)->lock);

		}



		spin_lock(&root->fs_info->delalloc_lock);

		BTRFS_I(inode)->delalloc_bytes += len;

		__percpu_counter_add(&root->fs_info->delalloc_bytes, len,

				     root->fs_info->delalloc_batch);

		if (do_list && list_empty(&BTRFS_I(inode)->delalloc_inodes)) {

		spin_lock(&BTRFS_I(inode)->lock);

		BTRFS_I(inode)->delalloc_bytes += len;

		if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,

					 &BTRFS_I(inode)->runtime_flags)) {

			spin_lock(&root->fs_info->delalloc_lock);

			if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {

				list_add_tail(&BTRFS_I(inode)->delalloc_inodes,

					      &root->fs_info->delalloc_inodes);

				set_bit(BTRFS_INODE_IN_DELALLOC_LIST,

					&BTRFS_I(inode)->runtime_flags);

			}

			spin_unlock(&root->fs_info->delalloc_lock);

		}

		spin_unlock(&BTRFS_I(inode)->lock);

	}

}



/*
@@ -1557,17 +1564,23 @@ static void btrfs_clear_bit_hook(struct inode *inode, 
		    && do_list)

			btrfs_free_reserved_data_space(inode, len);



		spin_lock(&root->fs_info->delalloc_lock);

		__percpu_counter_add(&root->fs_info->delalloc_bytes, -len,

				     root->fs_info->delalloc_batch);

		spin_lock(&BTRFS_I(inode)->lock);

		BTRFS_I(inode)->delalloc_bytes -= len;



		if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&

		    !list_empty(&BTRFS_I(inode)->delalloc_inodes)) {

		    test_bit(BTRFS_INODE_IN_DELALLOC_LIST,

			     &BTRFS_I(inode)->runtime_flags)) {

			spin_lock(&root->fs_info->delalloc_lock);

			if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {

				list_del_init(&BTRFS_I(inode)->delalloc_inodes);

				clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,

					  &BTRFS_I(inode)->runtime_flags);

			}

			spin_unlock(&root->fs_info->delalloc_lock);

		}

		spin_unlock(&BTRFS_I(inode)->lock);

	}

}



/*
@@ -7326,14 +7339,19 @@ fail: 
static int btrfs_getattr(struct vfsmount *mnt,

			 struct dentry *dentry, struct kstat *stat)

{

	u64 delalloc_bytes;

	struct inode *inode = dentry->d_inode;

	u32 blocksize = inode->i_sb->s_blocksize;



	generic_fillattr(inode, stat);

	stat->dev = BTRFS_I(inode)->root->anon_dev;

	stat->blksize = PAGE_CACHE_SIZE;



	spin_lock(&BTRFS_I(inode)->lock);

	delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;

	spin_unlock(&BTRFS_I(inode)->lock);

	stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +

		ALIGN(BTRFS_I(inode)->delalloc_bytes, blocksize)) >> 9;

			ALIGN(delalloc_bytes, blocksize)) >> 9;

	return 0;

}
@@ -7620,8 +7638,11 @@ int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput) 
		list_del_init(&binode->delalloc_inodes);



		inode = igrab(&binode->vfs_inode);

		if (!inode)

		if (!inode) {

			clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,

				  &binode->runtime_flags);

			continue;

		}



		list_add_tail(&binode->delalloc_inodes,

			      &root->fs_info->delalloc_inodes);