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: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
This commit is contained in:
Miao Xie 2013-01-29 10:11:59 +00:00 committed by Josef Bacik
parent 963d678b0f
commit df0af1a57f
3 changed files with 37 additions and 13 deletions

View File

@ -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 {

View File

@ -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);
}

View File

@ -1514,15 +1514,22 @@ 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)) {
list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
&root->fs_info->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(&root->fs_info->delalloc_lock);
spin_unlock(&BTRFS_I(inode)->lock);
}
}
@ -1557,16 +1564,22 @@ 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)) {
list_del_init(&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(&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);