From 9f9b8e8d0ebe1af42ddd3c86e12569c53914a89d Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Wed, 24 Oct 2018 20:24:01 +0800 Subject: [PATCH] btrfs: extent-tree: Detect bytes_may_use underflow earlier Although we have space_info::bytes_may_use underflow detection in btrfs_free_reserved_data_space_noquota(), we have more callers who are subtracting number from space_info::bytes_may_use. So instead of doing underflow detection for every caller, introduce a new wrapper update_bytes_may_use() to replace open coded bytes_may_use modifiers. This also introduce a macro to declare more wrappers, but currently space_info::bytes_may_use is the mostly interesting one. Reviewed-by: Josef Bacik Signed-off-by: Qu Wenruo Signed-off-by: Lu Fengqi Signed-off-by: David Sterba --- fs/btrfs/extent-tree.c | 46 +++++++++++++++++++++++++++--------------- 1 file changed, 30 insertions(+), 16 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index a1febf155747..395d9d55835f 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -51,6 +51,23 @@ enum { CHUNK_ALLOC_FORCE = 2, }; +/* + * Declare a helper function to detect underflow of various space info members + */ +#define DECLARE_SPACE_INFO_UPDATE(name) \ +static inline void update_##name(struct btrfs_space_info *sinfo, \ + s64 bytes) \ +{ \ + if (bytes < 0 && sinfo->name < -bytes) { \ + WARN_ON(1); \ + sinfo->name = 0; \ + return; \ + } \ + sinfo->name += bytes; \ +} + +DECLARE_SPACE_INFO_UPDATE(bytes_may_use); + static int __btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_node *node, u64 parent, u64 root_objectid, u64 owner_objectid, @@ -4256,7 +4273,7 @@ commit_trans: data_sinfo->flags, bytes, 1); return -ENOSPC; } - data_sinfo->bytes_may_use += bytes; + update_bytes_may_use(data_sinfo, bytes); trace_btrfs_space_reservation(fs_info, "space_info", data_sinfo->flags, bytes, 1); spin_unlock(&data_sinfo->lock); @@ -4309,10 +4326,7 @@ void btrfs_free_reserved_data_space_noquota(struct inode *inode, u64 start, data_sinfo = fs_info->data_sinfo; spin_lock(&data_sinfo->lock); - if (WARN_ON(data_sinfo->bytes_may_use < len)) - data_sinfo->bytes_may_use = 0; - else - data_sinfo->bytes_may_use -= len; + update_bytes_may_use(data_sinfo, -len); trace_btrfs_space_reservation(fs_info, "space_info", data_sinfo->flags, len, 0); spin_unlock(&data_sinfo->lock); @@ -5108,7 +5122,7 @@ static int wait_reserve_ticket(struct btrfs_fs_info *fs_info, list_del_init(&ticket->list); if (ticket->bytes && ticket->bytes < orig_bytes) { u64 num_bytes = orig_bytes - ticket->bytes; - space_info->bytes_may_use -= num_bytes; + update_bytes_may_use(space_info, -num_bytes); trace_btrfs_space_reservation(fs_info, "space_info", space_info->flags, num_bytes, 0); } @@ -5154,13 +5168,13 @@ static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info, * If not things get more complicated. */ if (used + orig_bytes <= space_info->total_bytes) { - space_info->bytes_may_use += orig_bytes; + update_bytes_may_use(space_info, orig_bytes); trace_btrfs_space_reservation(fs_info, "space_info", space_info->flags, orig_bytes, 1); ret = 0; } else if (can_overcommit(fs_info, space_info, orig_bytes, flush, system_chunk)) { - space_info->bytes_may_use += orig_bytes; + update_bytes_may_use(space_info, orig_bytes); trace_btrfs_space_reservation(fs_info, "space_info", space_info->flags, orig_bytes, 1); ret = 0; @@ -5223,7 +5237,7 @@ static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info, if (ticket.bytes) { if (ticket.bytes < orig_bytes) { u64 num_bytes = orig_bytes - ticket.bytes; - space_info->bytes_may_use -= num_bytes; + update_bytes_may_use(space_info, -num_bytes); trace_btrfs_space_reservation(fs_info, "space_info", space_info->flags, num_bytes, 0); @@ -5407,7 +5421,7 @@ again: flush = BTRFS_RESERVE_FLUSH_ALL; goto again; } - space_info->bytes_may_use -= num_bytes; + update_bytes_may_use(space_info, -num_bytes); trace_btrfs_space_reservation(fs_info, "space_info", space_info->flags, num_bytes, 0); spin_unlock(&space_info->lock); @@ -5435,7 +5449,7 @@ again: ticket->bytes, 1); list_del_init(&ticket->list); num_bytes -= ticket->bytes; - space_info->bytes_may_use += ticket->bytes; + update_bytes_may_use(space_info, ticket->bytes); ticket->bytes = 0; space_info->tickets_id++; wake_up(&ticket->wait); @@ -5443,7 +5457,7 @@ again: trace_btrfs_space_reservation(fs_info, "space_info", space_info->flags, num_bytes, 1); - space_info->bytes_may_use += num_bytes; + update_bytes_may_use(space_info, num_bytes); ticket->bytes -= num_bytes; num_bytes = 0; } @@ -5750,14 +5764,14 @@ static void update_global_block_rsv(struct btrfs_fs_info *fs_info) num_bytes = min(num_bytes, block_rsv->size - block_rsv->reserved); block_rsv->reserved += num_bytes; - sinfo->bytes_may_use += num_bytes; + update_bytes_may_use(sinfo, num_bytes); trace_btrfs_space_reservation(fs_info, "space_info", sinfo->flags, num_bytes, 1); } } else if (block_rsv->reserved > block_rsv->size) { num_bytes = block_rsv->reserved - block_rsv->size; - sinfo->bytes_may_use -= num_bytes; + update_bytes_may_use(sinfo, -num_bytes); trace_btrfs_space_reservation(fs_info, "space_info", sinfo->flags, num_bytes, 0); block_rsv->reserved = block_rsv->size; @@ -6431,7 +6445,7 @@ static int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache, } else { cache->reserved += num_bytes; space_info->bytes_reserved += num_bytes; - space_info->bytes_may_use -= ram_bytes; + update_bytes_may_use(space_info, -ram_bytes); if (delalloc) cache->delalloc_bytes += num_bytes; } @@ -6608,7 +6622,7 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info, to_add = min(len, global_rsv->size - global_rsv->reserved); global_rsv->reserved += to_add; - space_info->bytes_may_use += to_add; + update_bytes_may_use(space_info, to_add); if (global_rsv->reserved >= global_rsv->size) global_rsv->full = 1; trace_btrfs_space_reservation(fs_info,