Miao Xie
2013-Jan-10 12:50 UTC
[PATCH 08/11] 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>
---
fs/btrfs/btrfs_inode.h | 1 +
fs/btrfs/disk-io.c | 2 ++
fs/btrfs/inode.c | 47 ++++++++++++++++++++++++++++++++++-------------
3 files changed, 37 insertions(+), 13 deletions(-)
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 2a8c242..c935a77 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -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 {
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 750afd4..748ce06 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3685,6 +3685,8 @@ 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);
}
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index c29299d..f28ddf1 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1508,15 +1508,22 @@ 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);
}
}
@@ -1551,16 +1558,22 @@ 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);
}
}
@@ -7279,14 +7292,19 @@ 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;
}
@@ -7569,8 +7587,11 @@ int btrfs_start_delalloc_inodes(struct btrfs_root *root,
int delay_iput)
binode = list_entry(head->next, struct btrfs_inode,
delalloc_inodes);
inode = igrab(&binode->vfs_inode);
- if (!inode)
+ if (!inode) {
list_del_init(&binode->delalloc_inodes);
+ clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
+ &binode->runtime_flags);
+ }
spin_unlock(&root->fs_info->delalloc_lock);
if (inode) {
work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
--
1.7.11.7
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