From efc0e69c2feab8efcdbb9efdb9aae892d11b1545 Mon Sep 17 00:00:00 2001 From: Nikolay Borisov Date: Thu, 25 Nov 2021 11:14:41 +0200 Subject: [PATCH] btrfs: introduce exclusive operation BALANCE_PAUSED state Current set of exclusive operation states is not sufficient to handle all practical use cases. In particular there is a need to be able to add a device to a filesystem that have paused balance. Currently there is no way to distinguish between a running and a paused balance. Fix this by introducing BTRFS_EXCLOP_BALANCE_PAUSED which is going to be set in 2 occasions: 1. When a filesystem is mounted with skip_balance and there is an unfinished balance it will now be into BALANCE_PAUSED instead of simply BALANCE state. 2. When a running balance is paused. Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/ctree.h | 4 ++++ fs/btrfs/ioctl.c | 24 ++++++++++++++++++++++++ fs/btrfs/volumes.c | 10 ++++++++-- 3 files changed, 36 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 0c92158cb50c..4ea7157ca03c 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -611,6 +611,7 @@ enum { */ enum btrfs_exclusive_operation { BTRFS_EXCLOP_NONE, + BTRFS_EXCLOP_BALANCE_PAUSED, BTRFS_EXCLOP_BALANCE, BTRFS_EXCLOP_DEV_ADD, BTRFS_EXCLOP_DEV_REMOVE, @@ -3321,6 +3322,9 @@ bool btrfs_exclop_start_try_lock(struct btrfs_fs_info *fs_info, enum btrfs_exclusive_operation type); void btrfs_exclop_start_unlock(struct btrfs_fs_info *fs_info); void btrfs_exclop_finish(struct btrfs_fs_info *fs_info); +void btrfs_exclop_balance(struct btrfs_fs_info *fs_info, + enum btrfs_exclusive_operation op); + /* file.c */ int __init btrfs_auto_defrag_init(void); diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index af77098fdf35..6752e4b8b351 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -414,6 +414,29 @@ void btrfs_exclop_finish(struct btrfs_fs_info *fs_info) sysfs_notify(&fs_info->fs_devices->fsid_kobj, NULL, "exclusive_operation"); } +void btrfs_exclop_balance(struct btrfs_fs_info *fs_info, + enum btrfs_exclusive_operation op) +{ + switch (op) { + case BTRFS_EXCLOP_BALANCE_PAUSED: + spin_lock(&fs_info->super_lock); + ASSERT(fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE || + fs_info->exclusive_operation == BTRFS_EXCLOP_DEV_ADD); + fs_info->exclusive_operation = BTRFS_EXCLOP_BALANCE_PAUSED; + spin_unlock(&fs_info->super_lock); + break; + case BTRFS_EXCLOP_BALANCE: + spin_lock(&fs_info->super_lock); + ASSERT(fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE_PAUSED); + fs_info->exclusive_operation = BTRFS_EXCLOP_BALANCE; + spin_unlock(&fs_info->super_lock); + break; + default: + btrfs_warn(fs_info, + "invalid exclop balance operation %d requested", op); + } +} + static int btrfs_ioctl_getversion(struct file *file, int __user *arg) { struct inode *inode = file_inode(file); @@ -4056,6 +4079,7 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg) spin_lock(&fs_info->balance_lock); bctl->flags |= BTRFS_BALANCE_RESUME; spin_unlock(&fs_info->balance_lock); + btrfs_exclop_balance(fs_info, BTRFS_EXCLOP_BALANCE); goto do_balance; } diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 4f77268619f3..9db9d66b5470 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -4394,8 +4394,10 @@ int btrfs_balance(struct btrfs_fs_info *fs_info, ret = __btrfs_balance(fs_info); mutex_lock(&fs_info->balance_mutex); - if (ret == -ECANCELED && atomic_read(&fs_info->balance_pause_req)) + if (ret == -ECANCELED && atomic_read(&fs_info->balance_pause_req)) { btrfs_info(fs_info, "balance: paused"); + btrfs_exclop_balance(fs_info, BTRFS_EXCLOP_BALANCE_PAUSED); + } /* * Balance can be canceled by: * @@ -4471,6 +4473,10 @@ int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info) return 0; } + spin_lock(&fs_info->super_lock); + ASSERT(fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE_PAUSED); + fs_info->exclusive_operation = BTRFS_EXCLOP_BALANCE; + spin_unlock(&fs_info->super_lock); /* * A ro->rw remount sequence should continue with the paused balance * regardless of who pauses it, system or the user as of now, so set @@ -4539,7 +4545,7 @@ int btrfs_recover_balance(struct btrfs_fs_info *fs_info) * is in a paused state and must have fs_info::balance_ctl properly * set up. */ - if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) + if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE_PAUSED)) btrfs_warn(fs_info, "balance: cannot set exclusive op status, resume manually");