Btrfs: add skip_balance mount option

Since restriper kthread starts involuntarily on mount and can suck cpu
and memory bandwidth add a mount option to forcefully skip it.  The
restriper in that case hangs around in paused state and can be resumed
from userspace when it's convenient.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
This commit is contained in:
Ilya Dryomov 2012-01-16 22:04:48 +02:00
parent 596410151e
commit 9555c6c180
3 changed files with 17 additions and 5 deletions

View File

@ -1492,6 +1492,7 @@ struct btrfs_ioctl_defrag_range_args {
#define BTRFS_MOUNT_AUTO_DEFRAG (1 << 16)
#define BTRFS_MOUNT_INODE_MAP_CACHE (1 << 17)
#define BTRFS_MOUNT_RECOVERY (1 << 18)
#define BTRFS_MOUNT_SKIP_BALANCE (1 << 19)
#define btrfs_clear_opt(o, opt) ((o) &= ~BTRFS_MOUNT_##opt)
#define btrfs_set_opt(o, opt) ((o) |= BTRFS_MOUNT_##opt)

View File

@ -164,8 +164,9 @@ enum {
Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
Opt_enospc_debug, Opt_subvolrootid, Opt_defrag,
Opt_inode_cache, Opt_no_space_cache, Opt_recovery, Opt_err,
Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
Opt_err,
};
static match_table_t tokens = {
@ -200,6 +201,7 @@ static match_table_t tokens = {
{Opt_inode_cache, "inode_cache"},
{Opt_no_space_cache, "nospace_cache"},
{Opt_recovery, "recovery"},
{Opt_skip_balance, "skip_balance"},
{Opt_err, NULL},
};
@ -398,6 +400,9 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
printk(KERN_INFO "btrfs: enabling auto recovery");
btrfs_set_opt(info->mount_opt, RECOVERY);
break;
case Opt_skip_balance:
btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
break;
case Opt_err:
printk(KERN_INFO "btrfs: unrecognized mount option "
"'%s'\n", p);
@ -723,6 +728,8 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
seq_puts(seq, ",autodefrag");
if (btrfs_test_opt(root, INODE_MAP_CACHE))
seq_puts(seq, ",inode_cache");
if (btrfs_test_opt(root, SKIP_BALANCE))
seq_puts(seq, ",skip_balance");
return 0;
}

View File

@ -2707,15 +2707,19 @@ static int balance_kthread(void *data)
struct btrfs_balance_control *bctl =
(struct btrfs_balance_control *)data;
struct btrfs_fs_info *fs_info = bctl->fs_info;
int ret;
int ret = 0;
mutex_lock(&fs_info->volume_mutex);
mutex_lock(&fs_info->balance_mutex);
set_balance_control(bctl);
printk(KERN_INFO "btrfs: continuing balance\n");
ret = btrfs_balance(bctl, NULL);
if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
printk(KERN_INFO "btrfs: force skipping balance\n");
} else {
printk(KERN_INFO "btrfs: continuing balance\n");
ret = btrfs_balance(bctl, NULL);
}
mutex_unlock(&fs_info->balance_mutex);
mutex_unlock(&fs_info->volume_mutex);