diff options
author | Josef Bacik <josef@toxicpanda.com> | 2019-06-18 16:09:20 -0400 |
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committer | David Sterba <dsterba@suse.com> | 2019-07-02 12:30:52 +0200 |
commit | 41783ef24d56ce45452db7c413df9a3bdcc8d651 (patch) | |
tree | eb1b54cdaf8e34ffb528e4b96386813f77b8b44b /fs/btrfs/space-info.c | |
parent | 280c290881bc048bd5dbe02796173f55ca86e697 (diff) | |
download | linux-41783ef24d56ce45452db7c413df9a3bdcc8d651.tar.bz2 |
btrfs: move and export can_overcommit
This is the first piece of moving the space reservation code to
space-info.c
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/space-info.c')
-rw-r--r-- | fs/btrfs/space-info.c | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c index 6edcd9b7cab2..9dc30081c2db 100644 --- a/fs/btrfs/space-info.c +++ b/fs/btrfs/space-info.c @@ -172,3 +172,71 @@ struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info, rcu_read_unlock(); return NULL; } + +static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global) +{ + return (global->size << 1); +} + +int btrfs_can_overcommit(struct btrfs_fs_info *fs_info, + struct btrfs_space_info *space_info, u64 bytes, + enum btrfs_reserve_flush_enum flush, + bool system_chunk) +{ + struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; + u64 profile; + u64 space_size; + u64 avail; + u64 used; + int factor; + + /* Don't overcommit when in mixed mode. */ + if (space_info->flags & BTRFS_BLOCK_GROUP_DATA) + return 0; + + if (system_chunk) + profile = btrfs_system_alloc_profile(fs_info); + else + profile = btrfs_metadata_alloc_profile(fs_info); + + used = btrfs_space_info_used(space_info, false); + + /* + * We only want to allow over committing if we have lots of actual space + * free, but if we don't have enough space to handle the global reserve + * space then we could end up having a real enospc problem when trying + * to allocate a chunk or some other such important allocation. + */ + spin_lock(&global_rsv->lock); + space_size = calc_global_rsv_need_space(global_rsv); + spin_unlock(&global_rsv->lock); + if (used + space_size >= space_info->total_bytes) + return 0; + + used += space_info->bytes_may_use; + + avail = atomic64_read(&fs_info->free_chunk_space); + + /* + * If we have dup, raid1 or raid10 then only half of the free + * space is actually usable. For raid56, the space info used + * doesn't include the parity drive, so we don't have to + * change the math + */ + factor = btrfs_bg_type_to_factor(profile); + avail = div_u64(avail, factor); + + /* + * If we aren't flushing all things, let us overcommit up to + * 1/2th of the space. If we can flush, don't let us overcommit + * too much, let it overcommit up to 1/8 of the space. + */ + if (flush == BTRFS_RESERVE_FLUSH_ALL) + avail >>= 3; + else + avail >>= 1; + + if (used + bytes < space_info->total_bytes + avail) + return 1; + return 0; +} |