diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index f4a439e1a43f..0a805b8d61cc 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -33,6 +33,7 @@ #include #include #include +#include #include "extent_io.h" #include "extent_map.h" #include "async-thread.h" @@ -1322,6 +1323,8 @@ struct btrfs_stripe_hash_table { #define BTRFS_STRIPE_HASH_TABLE_BITS 11 +void btrfs_init_async_reclaim_work(struct work_struct *work); + /* fs_info */ struct reloc_control; struct btrfs_device; @@ -1697,6 +1700,9 @@ struct btrfs_fs_info { struct semaphore uuid_tree_rescan_sem; unsigned int update_uuid_tree_gen:1; + + /* Used to reclaim the metadata space in the background. */ + struct work_struct async_reclaim_work; }; struct btrfs_subvolume_writers { diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 983314932af3..4b1f16dd9ce3 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2291,6 +2291,7 @@ int open_ctree(struct super_block *sb, atomic_set(&fs_info->balance_cancel_req, 0); fs_info->balance_ctl = NULL; init_waitqueue_head(&fs_info->balance_wait_q); + btrfs_init_async_reclaim_work(&fs_info->async_reclaim_work); sb->s_blocksize = 4096; sb->s_blocksize_bits = blksize_bits(4096); @@ -3603,6 +3604,8 @@ int close_ctree(struct btrfs_root *root) /* clear out the rbtree of defraggable inodes */ btrfs_cleanup_defrag_inodes(fs_info); + cancel_work_sync(&fs_info->async_reclaim_work); + if (!(fs_info->sb->s_flags & MS_RDONLY)) { ret = btrfs_commit_super(root); if (ret) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 5590af92094b..15467e3f5876 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -4204,6 +4204,104 @@ static int flush_space(struct btrfs_root *root, return ret; } + +static inline u64 +btrfs_calc_reclaim_metadata_size(struct btrfs_root *root, + struct btrfs_space_info *space_info) +{ + u64 used; + u64 expected; + u64 to_reclaim; + + to_reclaim = min_t(u64, num_online_cpus() * 1024 * 1024, + 16 * 1024 * 1024); + spin_lock(&space_info->lock); + if (can_overcommit(root, space_info, to_reclaim, + BTRFS_RESERVE_FLUSH_ALL)) { + to_reclaim = 0; + goto out; + } + + used = space_info->bytes_used + space_info->bytes_reserved + + space_info->bytes_pinned + space_info->bytes_readonly + + space_info->bytes_may_use; + if (can_overcommit(root, space_info, 1024 * 1024, + BTRFS_RESERVE_FLUSH_ALL)) + expected = div_factor_fine(space_info->total_bytes, 95); + else + expected = div_factor_fine(space_info->total_bytes, 90); + + if (used > expected) + to_reclaim = used - expected; + else + to_reclaim = 0; + to_reclaim = min(to_reclaim, space_info->bytes_may_use + + space_info->bytes_reserved); +out: + spin_unlock(&space_info->lock); + + return to_reclaim; +} + +static inline int need_do_async_reclaim(struct btrfs_space_info *space_info, + struct btrfs_fs_info *fs_info, u64 used) +{ + return (used >= div_factor_fine(space_info->total_bytes, 98) && + !btrfs_fs_closing(fs_info) && + !test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state)); +} + +static int btrfs_need_do_async_reclaim(struct btrfs_space_info *space_info, + struct btrfs_fs_info *fs_info) +{ + u64 used; + + spin_lock(&space_info->lock); + used = space_info->bytes_used + space_info->bytes_reserved + + space_info->bytes_pinned + space_info->bytes_readonly + + space_info->bytes_may_use; + if (need_do_async_reclaim(space_info, fs_info, used)) { + spin_unlock(&space_info->lock); + return 1; + } + spin_unlock(&space_info->lock); + + return 0; +} + +static void btrfs_async_reclaim_metadata_space(struct work_struct *work) +{ + struct btrfs_fs_info *fs_info; + struct btrfs_space_info *space_info; + u64 to_reclaim; + int flush_state; + + fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work); + space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA); + + to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info->fs_root, + space_info); + if (!to_reclaim) + return; + + flush_state = FLUSH_DELAYED_ITEMS_NR; + do { + flush_space(fs_info->fs_root, space_info, to_reclaim, + to_reclaim, flush_state); + flush_state++; + if (!btrfs_need_do_async_reclaim(space_info, fs_info)) + return; + } while (flush_state <= COMMIT_TRANS); + + if (btrfs_need_do_async_reclaim(space_info, fs_info)) + queue_work(system_unbound_wq, work); +} + +void btrfs_init_async_reclaim_work(struct work_struct *work) +{ + INIT_WORK(work, btrfs_async_reclaim_metadata_space); +} + /** * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space * @root - the root we're allocating for @@ -4311,8 +4409,13 @@ again: if (ret && flush != BTRFS_RESERVE_NO_FLUSH) { flushing = true; space_info->flush = 1; + } else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) { + used += orig_bytes; + if (need_do_async_reclaim(space_info, root->fs_info, used) && + !work_busy(&root->fs_info->async_reclaim_work)) + queue_work(system_unbound_wq, + &root->fs_info->async_reclaim_work); } - spin_unlock(&space_info->lock); if (!ret || flush == BTRFS_RESERVE_NO_FLUSH) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 9601d25a4607..8f7c03db1f8d 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1413,6 +1413,7 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data) * this also happens on 'umount -rf' or on shutdown, when * the filesystem is busy. */ + cancel_work_sync(&fs_info->async_reclaim_work); /* wait for the uuid_scan task to finish */ down(&fs_info->uuid_tree_rescan_sem);