Btrfs: Use btrfs_join_transaction to avoid deadlocks during snapshot creation

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Snapshot creation happens at a specific time during transaction commit.  We
need to make sure the code called by snapshot creation doesn't wait
for the running transaction to commit.

This changes btrfs_delete_inode and finish_pending_snaps to use
btrfs_join_transaction instead of btrfs_start_transaction to avoid deadlocks.

It would be better if btrfs_delete_inode didn't use the join, but the
call path that triggers it is:

btrfs_commit_transaction->create_pending_snapshots->
create_pending_snapshot->btrfs_lookup_dentry->
fixup_tree_root_location->btrfs_read_fs_root->
btrfs_read_fs_root_no_name->btrfs_orphan_cleanup->iput

This will be fixed in a later patch by moving the orphan cleanup to the
cleaner thread.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

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This commit is contained in:

Yan Zheng 2009-01-06 09:58:06 -05:00 • committed by Chris Mason

parent 9ca03b997f

commit 180591bcfe

2 changed files with 2 additions and 2 deletions

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2

fs/btrfs/inode.c

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2

fs/btrfs/transaction.c

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