diff options
Diffstat (limited to 'fs/btrfs/extent-tree.c')
-rw-r--r-- | fs/btrfs/extent-tree.c | 90 |
1 files changed, 49 insertions, 41 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 0a5bd67e2894..d7031e7dfd76 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3726,7 +3726,6 @@ int btrfs_block_rsv_check(struct btrfs_trans_handle *trans, if (commit_trans) { if (trans) return -EAGAIN; - trans = btrfs_join_transaction(root); BUG_ON(IS_ERR(trans)); ret = btrfs_commit_transaction(trans, root); @@ -3946,6 +3945,30 @@ int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans, return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes); } +static unsigned drop_outstanding_extent(struct inode *inode) +{ + unsigned dropped_extents = 0; + + spin_lock(&BTRFS_I(inode)->lock); + BUG_ON(!BTRFS_I(inode)->outstanding_extents); + BTRFS_I(inode)->outstanding_extents--; + + /* + * If we have more or the same amount of outsanding extents than we have + * reserved then we need to leave the reserved extents count alone. + */ + if (BTRFS_I(inode)->outstanding_extents >= + BTRFS_I(inode)->reserved_extents) + goto out; + + dropped_extents = BTRFS_I(inode)->reserved_extents - + BTRFS_I(inode)->outstanding_extents; + BTRFS_I(inode)->reserved_extents -= dropped_extents; +out: + spin_unlock(&BTRFS_I(inode)->lock); + return dropped_extents; +} + static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes) { return num_bytes >>= 3; @@ -3955,9 +3978,8 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_block_rsv *block_rsv = &root->fs_info->delalloc_block_rsv; - u64 to_reserve; - int nr_extents; - int reserved_extents; + u64 to_reserve = 0; + unsigned nr_extents = 0; int ret; if (btrfs_transaction_in_commit(root->fs_info)) @@ -3965,24 +3987,31 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes) num_bytes = ALIGN(num_bytes, root->sectorsize); - nr_extents = atomic_read(&BTRFS_I(inode)->outstanding_extents) + 1; - reserved_extents = atomic_read(&BTRFS_I(inode)->reserved_extents); + spin_lock(&BTRFS_I(inode)->lock); + BTRFS_I(inode)->outstanding_extents++; + + if (BTRFS_I(inode)->outstanding_extents > + BTRFS_I(inode)->reserved_extents) { + nr_extents = BTRFS_I(inode)->outstanding_extents - + BTRFS_I(inode)->reserved_extents; + BTRFS_I(inode)->reserved_extents += nr_extents; - if (nr_extents > reserved_extents) { - nr_extents -= reserved_extents; to_reserve = btrfs_calc_trans_metadata_size(root, nr_extents); - } else { - nr_extents = 0; - to_reserve = 0; } + spin_unlock(&BTRFS_I(inode)->lock); to_reserve += calc_csum_metadata_size(inode, num_bytes); ret = reserve_metadata_bytes(NULL, root, block_rsv, to_reserve, 1); - if (ret) + if (ret) { + unsigned dropped; + /* + * We don't need the return value since our reservation failed, + * we just need to clean up our counter. + */ + dropped = drop_outstanding_extent(inode); + WARN_ON(dropped > 1); return ret; - - atomic_add(nr_extents, &BTRFS_I(inode)->reserved_extents); - atomic_inc(&BTRFS_I(inode)->outstanding_extents); + } block_rsv_add_bytes(block_rsv, to_reserve, 1); @@ -3992,36 +4021,15 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes) void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes) { struct btrfs_root *root = BTRFS_I(inode)->root; - u64 to_free; - int nr_extents; - int reserved_extents; + u64 to_free = 0; + unsigned dropped; num_bytes = ALIGN(num_bytes, root->sectorsize); - atomic_dec(&BTRFS_I(inode)->outstanding_extents); - WARN_ON(atomic_read(&BTRFS_I(inode)->outstanding_extents) < 0); - - reserved_extents = atomic_read(&BTRFS_I(inode)->reserved_extents); - do { - int old, new; - - nr_extents = atomic_read(&BTRFS_I(inode)->outstanding_extents); - if (nr_extents >= reserved_extents) { - nr_extents = 0; - break; - } - old = reserved_extents; - nr_extents = reserved_extents - nr_extents; - new = reserved_extents - nr_extents; - old = atomic_cmpxchg(&BTRFS_I(inode)->reserved_extents, - reserved_extents, new); - if (likely(old == reserved_extents)) - break; - reserved_extents = old; - } while (1); + dropped = drop_outstanding_extent(inode); to_free = calc_csum_metadata_size(inode, num_bytes); - if (nr_extents > 0) - to_free += btrfs_calc_trans_metadata_size(root, nr_extents); + if (dropped > 0) + to_free += btrfs_calc_trans_metadata_size(root, dropped); btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv, to_free); |