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authorJosef Bacik <josef@toxicpanda.com>2019-08-22 15:10:54 -0400
committerDavid Sterba <dsterba@suse.com>2019-09-09 14:59:17 +0200
commitef1317a1b9a347cdc3967a2048046e8fb4db94ba (patch)
treecbcfa88ce59b8a387a72cb9e2a9772ffdb4f3da2 /fs/btrfs
parente182163d9cbe86bc0f754068628df55e6dc073d3 (diff)
downloadlinux-ef1317a1b9a347cdc3967a2048046e8fb4db94ba.tar.bz2
btrfs: do not allow reservations if we have pending tickets
If we already have tickets on the list we don't want to steal their reservations. This is a preparation patch for upcoming changes, technically this shouldn't happen today because of the way we add bytes to tickets before adding them to the space_info in most cases. This does not change the FIFO nature of reserve tickets, it simply allows us to enforce it in a different way. Previously it was enforced because any new space would be added to the first ticket on the list, which would result in new reservations getting a reserve ticket. This replaces that mechanism by simply checking to see if we have outstanding reserve tickets and skipping straight to adding a ticket for our reservation. 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')
-rw-r--r--fs/btrfs/space-info.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
index bea7ae0a9739..918bffb6ba30 100644
--- a/fs/btrfs/space-info.c
+++ b/fs/btrfs/space-info.c
@@ -993,6 +993,7 @@ static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info,
struct reserve_ticket ticket;
u64 used;
int ret = 0;
+ bool pending_tickets;
ASSERT(orig_bytes);
ASSERT(!current->journal_info || flush != BTRFS_RESERVE_FLUSH_ALL);
@@ -1000,14 +1001,17 @@ static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info,
spin_lock(&space_info->lock);
ret = -ENOSPC;
used = btrfs_space_info_used(space_info, true);
+ pending_tickets = !list_empty(&space_info->tickets) ||
+ !list_empty(&space_info->priority_tickets);
/*
* Carry on if we have enough space (short-circuit) OR call
* can_overcommit() to ensure we can overcommit to continue.
*/
- if ((used + orig_bytes <= space_info->total_bytes) ||
- can_overcommit(fs_info, space_info, orig_bytes, flush,
- system_chunk)) {
+ if (!pending_tickets &&
+ ((used + orig_bytes <= space_info->total_bytes) ||
+ can_overcommit(fs_info, space_info, orig_bytes, flush,
+ system_chunk))) {
btrfs_space_info_update_bytes_may_use(fs_info, space_info,
orig_bytes);
trace_btrfs_space_reservation(fs_info, "space_info",