diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index af2bd059daae..98c5f6178efc 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -541,11 +541,6 @@ enum { BTRFS_FS_QUOTA_OVERRIDE, /* Used to record internally whether fs has been frozen */ BTRFS_FS_FROZEN, - /* - * Indicate that a whole-filesystem exclusive operation is running - * (device replace, resize, device add/delete, balance) - */ - BTRFS_FS_EXCL_OP, /* * Indicate that balance has been set up from the ioctl and is in the * main phase. The fs_info::balance_ctl is initialized. @@ -566,6 +561,19 @@ enum { BTRFS_FS_DISCARD_RUNNING, }; +/* + * Exclusive operations (device replace, resize, device add/remove, balance) + */ +enum btrfs_exclusive_operation { + BTRFS_EXCLOP_NONE, + BTRFS_EXCLOP_BALANCE, + BTRFS_EXCLOP_DEV_ADD, + BTRFS_EXCLOP_DEV_REMOVE, + BTRFS_EXCLOP_DEV_REPLACE, + BTRFS_EXCLOP_RESIZE, + BTRFS_EXCLOP_SWAP_ACTIVATE, +}; + struct btrfs_fs_info { u8 chunk_tree_uuid[BTRFS_UUID_SIZE]; unsigned long flags; @@ -937,6 +945,9 @@ struct btrfs_fs_info { */ int send_in_progress; + /* Type of exclusive operation running */ + unsigned long exclusive_operation; + #ifdef CONFIG_BTRFS_FS_REF_VERIFY spinlock_t ref_verify_lock; struct rb_root block_tree; @@ -3032,6 +3043,9 @@ void btrfs_get_block_group_info(struct list_head *groups_list, struct btrfs_ioctl_space_info *space); void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info, struct btrfs_ioctl_balance_args *bargs); +bool btrfs_exclop_start(struct btrfs_fs_info *fs_info, + enum btrfs_exclusive_operation type); +void btrfs_exclop_finish(struct btrfs_fs_info *fs_info); /* file.c */ int __init btrfs_auto_defrag_init(void); diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index 61d800a149b0..14901ca2508d 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -1025,7 +1025,7 @@ int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) * should never allow both to start and pause. We don't want to allow * dev-replace to start anyway. */ - if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) { + if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REPLACE)) { down_write(&dev_replace->rwsem); dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; @@ -1062,7 +1062,7 @@ static int btrfs_dev_replace_kthread(void *data) ret = btrfs_dev_replace_finishing(fs_info, ret); WARN_ON(ret && ret != -ECANCELED); - clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags); + btrfs_exclop_finish(fs_info); return 0; } diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index a66145aac710..cce6f8789a4e 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -10015,14 +10015,14 @@ static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file, /* * Balance or device remove/replace/resize can move stuff around from - * under us. The EXCL_OP flag makes sure they aren't running/won't run - * concurrently while we are mapping the swap extents, and - * fs_info->swapfile_pins prevents them from running while the swap file - * is active and moving the extents. Note that this also prevents a - * concurrent device add which isn't actually necessary, but it's not + * under us. The exclop protection makes sure they aren't running/won't + * run concurrently while we are mapping the swap extents, and + * fs_info->swapfile_pins prevents them from running while the swap + * file is active and moving the extents. Note that this also prevents + * a concurrent device add which isn't actually necessary, but it's not * really worth the trouble to allow it. */ - if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) { + if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_SWAP_ACTIVATE)) { btrfs_warn(fs_info, "cannot activate swapfile while exclusive operation is running"); return -EBUSY; @@ -10168,7 +10168,7 @@ out: if (ret) btrfs_swap_deactivate(file); - clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags); + btrfs_exclop_finish(fs_info); if (ret) return ret; diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index b91444e810a5..f30231596fe0 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -378,6 +378,17 @@ static int check_xflags(unsigned int flags) return 0; } +bool btrfs_exclop_start(struct btrfs_fs_info *fs_info, + enum btrfs_exclusive_operation type) +{ + return !cmpxchg(&fs_info->exclusive_operation, BTRFS_EXCLOP_NONE, type); +} + +void btrfs_exclop_finish(struct btrfs_fs_info *fs_info) +{ + WRITE_ONCE(fs_info->exclusive_operation, BTRFS_EXCLOP_NONE); +} + /* * Set the xflags from the internal inode flags. The remaining items of fsxattr * are zeroed. @@ -1639,7 +1650,7 @@ static noinline int btrfs_ioctl_resize(struct file *file, if (ret) return ret; - if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) { + if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_RESIZE)) { mnt_drop_write_file(file); return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS; } @@ -1753,7 +1764,7 @@ static noinline int btrfs_ioctl_resize(struct file *file, out_free: kfree(vol_args); out: - clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags); + btrfs_exclop_finish(fs_info); mnt_drop_write_file(file); return ret; } @@ -3127,7 +3138,7 @@ static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg) if (!capable(CAP_SYS_ADMIN)) return -EPERM; - if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) + if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_ADD)) return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS; vol_args = memdup_user(arg, sizeof(*vol_args)); @@ -3144,7 +3155,7 @@ static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg) kfree(vol_args); out: - clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags); + btrfs_exclop_finish(fs_info); return ret; } @@ -3173,7 +3184,7 @@ static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg) goto out; } - if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) { + if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REMOVE)) { ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS; goto out; } @@ -3184,7 +3195,7 @@ static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg) vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0'; ret = btrfs_rm_device(fs_info, vol_args->name, 0); } - clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags); + btrfs_exclop_finish(fs_info); if (!ret) { if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) @@ -3215,7 +3226,7 @@ static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg) if (ret) return ret; - if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) { + if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REMOVE)) { ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS; goto out_drop_write; } @@ -3233,7 +3244,7 @@ static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg) btrfs_info(fs_info, "disk deleted %s", vol_args->name); kfree(vol_args); out: - clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags); + btrfs_exclop_finish(fs_info); out_drop_write: mnt_drop_write_file(file); @@ -3737,11 +3748,11 @@ static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info, ret = -EROFS; goto out; } - if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) { + if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REPLACE)) { ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS; } else { ret = btrfs_dev_replace_by_ioctl(fs_info, p); - clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags); + btrfs_exclop_finish(fs_info); } break; case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS: @@ -3952,7 +3963,7 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg) return ret; again: - if (!test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) { + if (btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) { mutex_lock(&fs_info->balance_mutex); need_unlock = true; goto locked; @@ -3998,7 +4009,6 @@ again: } locked: - BUG_ON(!test_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)); if (arg) { bargs = memdup_user(arg, sizeof(*bargs)); @@ -4053,10 +4063,10 @@ locked: do_balance: /* - * Ownership of bctl and filesystem flag BTRFS_FS_EXCL_OP goes to - * btrfs_balance. bctl is freed in reset_balance_state, or, if - * restriper was paused all the way until unmount, in free_fs_info. - * The flag should be cleared after reset_balance_state. + * Ownership of bctl and exclusive operation goes to btrfs_balance. + * bctl is freed in reset_balance_state, or, if restriper was paused + * all the way until unmount, in free_fs_info. The flag should be + * cleared after reset_balance_state. */ need_unlock = false; @@ -4075,7 +4085,7 @@ out_bargs: out_unlock: mutex_unlock(&fs_info->balance_mutex); if (need_unlock) - clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags); + btrfs_exclop_finish(fs_info); out: mnt_drop_write_file(file); return ret; diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index c86ffad04641..cbebb5d06773 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -291,8 +291,8 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, * balance_mutex * * - * Exclusive operations, BTRFS_FS_EXCL_OP - * ====================================== + * Exclusive operations + * ==================== * * Maintains the exclusivity of the following operations that apply to the * whole filesystem and cannot run in parallel. @@ -318,11 +318,11 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, * - system power-cycle and filesystem mounted as read-only * - filesystem or device errors leading to forced read-only * - * BTRFS_FS_EXCL_OP flag is set and cleared using atomic operations. - * During the course of Paused state, the BTRFS_FS_EXCL_OP remains set. + * The status of exclusive operation is set and cleared atomically. + * During the course of Paused state, fs_info::exclusive_operation remains set. * A device operation in Paused or Running state can be canceled or resumed * either by ioctl (Balance only) or when remounted as read-write. - * BTRFS_FS_EXCL_OP flag is cleared when the device operation is canceled or + * The exclusive status is cleared when the device operation is canceled or * completed. */ @@ -4033,7 +4033,7 @@ int btrfs_balance(struct btrfs_fs_info *fs_info, /* * rw_devices will not change at the moment, device add/delete/replace - * are excluded by EXCL_OP + * are exclusive */ num_devices = fs_info->fs_devices->rw_devices; @@ -4169,7 +4169,7 @@ int btrfs_balance(struct btrfs_fs_info *fs_info, if ((ret && ret != -ECANCELED && ret != -ENOSPC) || balance_need_close(fs_info)) { reset_balance_state(fs_info); - clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags); + btrfs_exclop_finish(fs_info); } wake_up(&fs_info->balance_wait_q); @@ -4180,7 +4180,7 @@ out: reset_balance_state(fs_info); else kfree(bctl); - clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags); + btrfs_exclop_finish(fs_info); return ret; } @@ -4282,7 +4282,7 @@ 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 (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) + if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) btrfs_warn(fs_info, "balance: cannot set exclusive op status, resume manually"); @@ -4364,7 +4364,7 @@ int btrfs_cancel_balance(struct btrfs_fs_info *fs_info) if (fs_info->balance_ctl) { reset_balance_state(fs_info); - clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags); + btrfs_exclop_finish(fs_info); btrfs_info(fs_info, "balance: canceled"); } }