From 8b228324a8ce03083a034dfa784bc10696ce7489 Mon Sep 17 00:00:00 2001 From: Boris Burkov Date: Wed, 18 Nov 2020 15:06:21 -0800 Subject: btrfs: clear free space tree on ro->rw remount A user might want to revert to v1 or nospace_cache on a root filesystem, and much like turning on the free space tree, that can only be done remounting from ro->rw. Support clearing the free space tree on such mounts by moving it into the shared remount logic. Since the CLEAR_CACHE option sticks around across remounts, this change would result in clearing the tree for ever on every remount, which is not desirable. To fix that, add CLEAR_CACHE to the oneshot options we clear at mount end, which has the other bonus of not cluttering the /proc/mounts output with clear_cache. Reviewed-by: Josef Bacik Signed-off-by: Boris Burkov Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/disk-io.c | 42 +++++++++++++++++++++--------------------- 1 file changed, 21 insertions(+), 21 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 292ea49f5ae3..77c7013f69d7 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2878,6 +2878,7 @@ static int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info) void btrfs_clear_oneshot_options(struct btrfs_fs_info *fs_info) { btrfs_clear_opt(fs_info->mount_opt, USEBACKUPROOT); + btrfs_clear_opt(fs_info->mount_opt, CLEAR_CACHE); } /* @@ -2887,6 +2888,26 @@ void btrfs_clear_oneshot_options(struct btrfs_fs_info *fs_info) int btrfs_start_pre_rw_mount(struct btrfs_fs_info *fs_info) { int ret; + bool clear_free_space_tree = false; + + if (btrfs_test_opt(fs_info, CLEAR_CACHE) && + btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) { + clear_free_space_tree = true; + } else if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) && + !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID)) { + btrfs_warn(fs_info, "free space tree is invalid"); + clear_free_space_tree = true; + } + + if (clear_free_space_tree) { + btrfs_info(fs_info, "clearing free space tree"); + ret = btrfs_clear_free_space_tree(fs_info); + if (ret) { + btrfs_warn(fs_info, + "failed to clear free space tree: %d", ret); + goto out; + } + } ret = btrfs_cleanup_fs_roots(fs_info); if (ret) @@ -2960,7 +2981,6 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device struct btrfs_root *chunk_root; int ret; int err = -EINVAL; - int clear_free_space_tree = 0; int level; ret = init_mount_fs_info(fs_info, sb); @@ -3371,26 +3391,6 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device if (sb_rdonly(sb)) goto clear_oneshot; - if (btrfs_test_opt(fs_info, CLEAR_CACHE) && - btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) { - clear_free_space_tree = 1; - } else if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) && - !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID)) { - btrfs_warn(fs_info, "free space tree is invalid"); - clear_free_space_tree = 1; - } - - if (clear_free_space_tree) { - btrfs_info(fs_info, "clearing free space tree"); - ret = btrfs_clear_free_space_tree(fs_info); - if (ret) { - btrfs_warn(fs_info, - "failed to clear free space tree: %d", ret); - close_ctree(fs_info); - return ret; - } - } - ret = btrfs_start_pre_rw_mount(fs_info); if (ret) { close_ctree(fs_info); -- cgit v1.2.3