From d5c8238849e7bae6063dfc16c08ed62cee7ee688 Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Wed, 21 Oct 2020 13:17:24 -0700 Subject: [PATCH] btrfs: convert data_seqcount to seqcount_mutex_t By doing so we can associate the sequence counter to the chunk_mutex for lockdep purposes (compiled-out otherwise), the mutex is otherwise used on the write side. Also avoid explicitly disabling preemption around the write region as it will now be done automatically by the seqcount machinery based on the lock type. Signed-off-by: Davidlohr Bueso Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/volumes.c | 2 +- fs/btrfs/volumes.h | 11 +++++------ 2 files changed, 6 insertions(+), 7 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 1991bc5a6f59..b1e48078c318 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -431,7 +431,7 @@ static struct btrfs_device *__alloc_device(struct btrfs_fs_info *fs_info) atomic_set(&dev->reada_in_flight, 0); atomic_set(&dev->dev_stats_ccnt, 0); - btrfs_device_data_ordered_init(dev); + btrfs_device_data_ordered_init(dev, fs_info); INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_DIRECT_RECLAIM); INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_DIRECT_RECLAIM); extent_io_tree_init(fs_info, &dev->alloc_state, diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index f2177263748e..232f02bd214f 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -39,10 +39,10 @@ struct btrfs_io_geometry { #if BITS_PER_LONG==32 && defined(CONFIG_SMP) #include #define __BTRFS_NEED_DEVICE_DATA_ORDERED -#define btrfs_device_data_ordered_init(device) \ - seqcount_init(&device->data_seqcount) +#define btrfs_device_data_ordered_init(device, info) \ + seqcount_mutex_init(&device->data_seqcount, &info->chunk_mutex) #else -#define btrfs_device_data_ordered_init(device) do { } while (0) +#define btrfs_device_data_ordered_init(device, info) do { } while (0) #endif #define BTRFS_DEV_STATE_WRITEABLE (0) @@ -72,7 +72,8 @@ struct btrfs_device { blk_status_t last_flush_error; #ifdef __BTRFS_NEED_DEVICE_DATA_ORDERED - seqcount_t data_seqcount; + /* A seqcount_t with associated chunk_mutex (for lockdep) */ + seqcount_mutex_t data_seqcount; #endif /* the internal btrfs device id */ @@ -163,11 +164,9 @@ btrfs_device_get_##name(const struct btrfs_device *dev) \ static inline void \ btrfs_device_set_##name(struct btrfs_device *dev, u64 size) \ { \ - preempt_disable(); \ write_seqcount_begin(&dev->data_seqcount); \ dev->name = size; \ write_seqcount_end(&dev->data_seqcount); \ - preempt_enable(); \ } #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) #define BTRFS_DEVICE_GETSET_FUNCS(name) \