Btrfs: Replace the transaction work queue with kthreads
This creates one kthread for commits and one kthread for
deleting old snapshots. All the work queues are removed.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 52569b5..31ca9f8 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -16,6 +16,7 @@
* Boston, MA 021110-1307, USA.
*/
+#include <linux/version.h>
#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/scatterlist.h>
@@ -24,6 +25,12 @@
#include <linux/writeback.h>
#include <linux/buffer_head.h> // for block_sync_page
#include <linux/workqueue.h>
+#include <linux/kthread.h>
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
+# include <linux/freezer.h>
+#else
+# include <linux/sched.h>
+#endif
#include "crc32c.h"
#include "ctree.h"
#include "disk-io.h"
@@ -1100,6 +1107,87 @@
#endif
}
+static int cleaner_kthread(void *arg)
+{
+ struct btrfs_root *root = arg;
+
+ do {
+ smp_mb();
+ if (root->fs_info->closing)
+ break;
+
+ vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
+ mutex_lock(&root->fs_info->cleaner_mutex);
+printk("cleaner awake\n");
+ btrfs_clean_old_snapshots(root);
+printk("cleaner done\n");
+ mutex_unlock(&root->fs_info->cleaner_mutex);
+
+ if (freezing(current)) {
+ refrigerator();
+ } else {
+ smp_mb();
+ if (root->fs_info->closing)
+ break;
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule();
+ __set_current_state(TASK_RUNNING);
+ }
+ } while (!kthread_should_stop());
+ return 0;
+}
+
+static int transaction_kthread(void *arg)
+{
+ struct btrfs_root *root = arg;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_transaction *cur;
+ unsigned long now;
+ unsigned long delay;
+ int ret;
+
+ do {
+ smp_mb();
+ if (root->fs_info->closing)
+ break;
+
+ delay = HZ * 30;
+ vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
+ mutex_lock(&root->fs_info->transaction_kthread_mutex);
+
+ mutex_lock(&root->fs_info->trans_mutex);
+ cur = root->fs_info->running_transaction;
+ if (!cur) {
+ mutex_unlock(&root->fs_info->trans_mutex);
+ goto sleep;
+ }
+ now = get_seconds();
+ if (now < cur->start_time || now - cur->start_time < 30) {
+ mutex_unlock(&root->fs_info->trans_mutex);
+ delay = HZ * 5;
+ goto sleep;
+ }
+ mutex_unlock(&root->fs_info->trans_mutex);
+ btrfs_defrag_dirty_roots(root->fs_info);
+ trans = btrfs_start_transaction(root, 1);
+ ret = btrfs_commit_transaction(trans, root);
+sleep:
+ wake_up_process(root->fs_info->cleaner_kthread);
+ mutex_unlock(&root->fs_info->transaction_kthread_mutex);
+
+ if (freezing(current)) {
+ refrigerator();
+ } else {
+ if (root->fs_info->closing)
+ break;
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(delay);
+ __set_current_state(TASK_RUNNING);
+ }
+ } while (!kthread_should_stop());
+ return 0;
+}
+
struct btrfs_root *open_ctree(struct super_block *sb,
struct btrfs_fs_devices *fs_devices,
char *options)
@@ -1189,11 +1277,6 @@
fs_info->btree_inode->i_mapping, GFP_NOFS);
fs_info->do_barriers = 1;
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
- INIT_WORK(&fs_info->trans_work, btrfs_transaction_cleaner, fs_info);
-#else
- INIT_DELAYED_WORK(&fs_info->trans_work, btrfs_transaction_cleaner);
-#endif
BTRFS_I(fs_info->btree_inode)->root = tree_root;
memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
sizeof(struct btrfs_key));
@@ -1204,6 +1287,8 @@
mutex_init(&fs_info->drop_mutex);
mutex_init(&fs_info->alloc_mutex);
mutex_init(&fs_info->chunk_mutex);
+ mutex_init(&fs_info->transaction_kthread_mutex);
+ mutex_init(&fs_info->cleaner_mutex);
#if 0
ret = add_hasher(fs_info, "crc32c");
@@ -1247,7 +1332,6 @@
btrfs_start_workers(&fs_info->submit_workers, 1);
btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
-
err = -EINVAL;
if (btrfs_super_num_devices(disk_super) > fs_devices->open_devices) {
printk("Btrfs: wanted %llu devices, but found %llu\n",
@@ -1341,9 +1425,22 @@
fs_info->data_alloc_profile = (u64)-1;
fs_info->metadata_alloc_profile = (u64)-1;
fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
+ fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
+ "btrfs-cleaner");
+ if (!fs_info->cleaner_kthread)
+ goto fail_extent_root;
+
+ fs_info->transaction_kthread = kthread_run(transaction_kthread,
+ tree_root,
+ "btrfs-transaction");
+ if (!fs_info->transaction_kthread)
+ goto fail_trans_kthread;
+
return tree_root;
+fail_trans_kthread:
+ kthread_stop(fs_info->cleaner_kthread);
fail_extent_root:
free_extent_buffer(extent_root->node);
fail_tree_root:
@@ -1562,8 +1659,11 @@
fs_info->closing = 1;
smp_mb();
- btrfs_transaction_flush_work(root);
+ kthread_stop(root->fs_info->transaction_kthread);
+ kthread_stop(root->fs_info->cleaner_kthread);
+
btrfs_defrag_dirty_roots(root->fs_info);
+ btrfs_clean_old_snapshots(root);
trans = btrfs_start_transaction(root, 1);
ret = btrfs_commit_transaction(trans, root);
/* run commit again to drop the original snapshot */
@@ -1574,8 +1674,6 @@
write_ctree_super(NULL, root);
- btrfs_transaction_flush_work(root);
-
if (fs_info->delalloc_bytes) {
printk("btrfs: at unmount delalloc count %Lu\n",
fs_info->delalloc_bytes);