From c64c2bd890df3b9a66c52c33df110777058c011e Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Fri, 14 Dec 2012 13:48:14 -0500 Subject: [PATCH] Btrfs: don't take inode delalloc mutex if we're a free space inode This confuses and angers lockdep even though it's ok. We don't really need the lock for free space inodes since only the transaction committer will be reserving space. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/extent-tree.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index afc3ac5..d133edf 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -4535,16 +4535,25 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes) int extra_reserve = 0; enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_FLUSH_ALL; int ret; + bool delalloc_lock = true; - /* Need to be holding the i_mutex here if we aren't free space cache */ - if (btrfs_is_free_space_inode(inode)) + /* If we are a free space inode we need to not flush since we will be in + * the middle of a transaction commit. We also don't need the delalloc + * mutex since we won't race with anybody. We need this mostly to make + * lockdep shut its filthy mouth. + */ + if (btrfs_is_free_space_inode(inode)) { flush = BTRFS_RESERVE_NO_FLUSH; + delalloc_lock = false; + } if (flush != BTRFS_RESERVE_NO_FLUSH && btrfs_transaction_in_commit(root->fs_info)) schedule_timeout(1); - mutex_lock(&BTRFS_I(inode)->delalloc_mutex); + if (delalloc_lock) + mutex_lock(&BTRFS_I(inode)->delalloc_mutex); + num_bytes = ALIGN(num_bytes, root->sectorsize); spin_lock(&BTRFS_I(inode)->lock); @@ -4577,7 +4586,8 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes) spin_lock(&BTRFS_I(inode)->lock); calc_csum_metadata_size(inode, num_bytes, 0); spin_unlock(&BTRFS_I(inode)->lock); - mutex_unlock(&BTRFS_I(inode)->delalloc_mutex); + if (delalloc_lock) + mutex_unlock(&BTRFS_I(inode)->delalloc_mutex); return ret; } } @@ -4616,7 +4626,8 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes) btrfs_qgroup_free(root, num_bytes + nr_extents * root->leafsize); } - mutex_unlock(&BTRFS_I(inode)->delalloc_mutex); + if (delalloc_lock) + mutex_unlock(&BTRFS_I(inode)->delalloc_mutex); return ret; } @@ -4628,7 +4639,9 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes) } BTRFS_I(inode)->reserved_extents += nr_extents; spin_unlock(&BTRFS_I(inode)->lock); - mutex_unlock(&BTRFS_I(inode)->delalloc_mutex); + + if (delalloc_lock) + mutex_unlock(&BTRFS_I(inode)->delalloc_mutex); if (to_reserve) trace_btrfs_space_reservation(root->fs_info,"delalloc", -- 2.7.4