Btrfs: use seqlock to protect fs_info->avail_{data, metadata, system}_alloc_bits

[cascardo/linux.git] / fs / btrfs / extent-tree.c

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 82400b2..faff98f 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3227,12 +3227,14 @@ static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
        u64 extra_flags = chunk_to_extended(flags) &
                                BTRFS_EXTENDED_PROFILE_MASK;
 
+       write_seqlock(&fs_info->profiles_lock);
        if (flags & BTRFS_BLOCK_GROUP_DATA)
                fs_info->avail_data_alloc_bits |= extra_flags;
        if (flags & BTRFS_BLOCK_GROUP_METADATA)
                fs_info->avail_metadata_alloc_bits |= extra_flags;
        if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
                fs_info->avail_system_alloc_bits |= extra_flags;
+       write_sequnlock(&fs_info->profiles_lock);
 }
 
 /*
@@ -3324,12 +3326,18 @@ u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
 
 static u64 get_alloc_profile(struct btrfs_root *root, u64 flags)
 {
-       if (flags & BTRFS_BLOCK_GROUP_DATA)
-               flags |= root->fs_info->avail_data_alloc_bits;
-       else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
-               flags |= root->fs_info->avail_system_alloc_bits;
-       else if (flags & BTRFS_BLOCK_GROUP_METADATA)
-               flags |= root->fs_info->avail_metadata_alloc_bits;
+       unsigned seq;
+
+       do {
+               seq = read_seqbegin(&root->fs_info->profiles_lock);
+
+               if (flags & BTRFS_BLOCK_GROUP_DATA)
+                       flags |= root->fs_info->avail_data_alloc_bits;
+               else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
+                       flags |= root->fs_info->avail_system_alloc_bits;
+               else if (flags & BTRFS_BLOCK_GROUP_METADATA)
+                       flags |= root->fs_info->avail_metadata_alloc_bits;
+       } while (read_seqretry(&root->fs_info->profiles_lock, seq));
 
        return btrfs_reduce_alloc_profile(root, flags);
 }
@@ -3760,7 +3768,8 @@ static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig,
        space_info = block_rsv->space_info;
 
        smp_mb();
-       delalloc_bytes = root->fs_info->delalloc_bytes;
+       delalloc_bytes = percpu_counter_sum_positive(
+                                               &root->fs_info->delalloc_bytes);
        if (delalloc_bytes == 0) {
                if (trans)
                        return;
@@ -3799,7 +3808,8 @@ static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig,
                                break;
                }
                smp_mb();
-               delalloc_bytes = root->fs_info->delalloc_bytes;
+               delalloc_bytes = percpu_counter_sum_positive(
+                                               &root->fs_info->delalloc_bytes);
        }
 }
 
@@ -5545,20 +5555,16 @@ wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
 
 int __get_raid_index(u64 flags)
 {
-       int index;
-
        if (flags & BTRFS_BLOCK_GROUP_RAID10)
-               index = 0;
+               return BTRFS_RAID_RAID10;
        else if (flags & BTRFS_BLOCK_GROUP_RAID1)
-               index = 1;
+               return BTRFS_RAID_RAID1;
        else if (flags & BTRFS_BLOCK_GROUP_DUP)
-               index = 2;
+               return BTRFS_RAID_DUP;
        else if (flags & BTRFS_BLOCK_GROUP_RAID0)
-               index = 3;
+               return BTRFS_RAID_RAID0;
        else
-               index = 4;
-
-       return index;
+               return BTRFS_RAID_SINGLE;
 }
 
 static int get_block_group_index(struct btrfs_block_group_cache *cache)
@@ -7518,16 +7524,16 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
                index = get_block_group_index(block_group);
        }
 
-       if (index == 0) {
+       if (index == BTRFS_RAID_RAID10) {
                dev_min = 4;
                /* Divide by 2 */
                min_free >>= 1;
-       } else if (index == 1) {
+       } else if (index == BTRFS_RAID_RAID1) {
                dev_min = 2;
-       } else if (index == 2) {
+       } else if (index == BTRFS_RAID_DUP) {
                /* Multiply by 2 */
                min_free <<= 1;
-       } else if (index == 3) {
+       } else if (index == BTRFS_RAID_RAID0) {
                dev_min = fs_devices->rw_devices;
                do_div(min_free, dev_min);
        }
@@ -7969,12 +7975,14 @@ static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
        u64 extra_flags = chunk_to_extended(flags) &
                                BTRFS_EXTENDED_PROFILE_MASK;
 
+       write_seqlock(&fs_info->profiles_lock);
        if (flags & BTRFS_BLOCK_GROUP_DATA)
                fs_info->avail_data_alloc_bits &= ~extra_flags;
        if (flags & BTRFS_BLOCK_GROUP_METADATA)
                fs_info->avail_metadata_alloc_bits &= ~extra_flags;
        if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
                fs_info->avail_system_alloc_bits &= ~extra_flags;
+       write_sequnlock(&fs_info->profiles_lock);
 }
 
 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,