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author | Zhao Lei <zhaolei@cn.fujitsu.com> | 2015-02-26 10:49:20 +0800 |
---|---|---|
committer | Chris Mason <clm@fb.com> | 2015-04-13 07:27:41 -0700 |
commit | d7c151717a1efe289aec29fb9f94485f64262c0b (patch) | |
tree | 64a17c0b1403fbbb14e474e101a997f117de237c | |
parent | 18d018ad2c899d3d9c503c25125d56046ed7d3ca (diff) | |
download | op-kernel-dev-d7c151717a1efe289aec29fb9f94485f64262c0b.zip op-kernel-dev-d7c151717a1efe289aec29fb9f94485f64262c0b.tar.gz |
btrfs: Fix NO_SPACE bug caused by delayed-iput
Steps to reproduce:
while true; do
dd if=/dev/zero of=/btrfs_dir/file count=[fs_size * 75%]
rm /btrfs_dir/file
sync
done
And we'll see dd failed because btrfs return NO_SPACE.
Reason:
Normally, btrfs_commit_transaction() call btrfs_run_delayed_iputs()
in end to free fs space for next write, but sometimes it hadn't
done work on time, because btrfs-cleaner thread get delayed-iputs
from list before, but do iput() after next write.
This is log:
[ 2569.050776] comm=btrfs-cleaner func=btrfs_evict_inode() begin
[ 2569.084280] comm=sync func=btrfs_commit_transaction() call btrfs_run_delayed_iputs()
[ 2569.085418] comm=sync func=btrfs_commit_transaction() done btrfs_run_delayed_iputs()
[ 2569.087554] comm=sync func=btrfs_commit_transaction() end
[ 2569.191081] comm=dd begin
[ 2569.790112] comm=dd func=__btrfs_buffered_write() ret=-28
[ 2569.847479] comm=btrfs-cleaner func=add_pinned_bytes() 0 + 32677888 = 32677888
[ 2569.849530] comm=btrfs-cleaner func=add_pinned_bytes() 32677888 + 23834624 = 56512512
...
[ 2569.903893] comm=btrfs-cleaner func=add_pinned_bytes() 943976448 + 21762048 = 965738496
[ 2569.908270] comm=btrfs-cleaner func=btrfs_evict_inode() end
Fix:
Make btrfs_commit_transaction() wait current running btrfs-cleaner's
delayed-iputs() done in end.
Test:
Use script similar to above(more complex),
before patch:
7 failed in 100 * 20 loop.
after patch:
0 failed in 100 * 20 loop.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
-rw-r--r-- | fs/btrfs/ctree.h | 1 | ||||
-rw-r--r-- | fs/btrfs/disk-io.c | 3 | ||||
-rw-r--r-- | fs/btrfs/extent-tree.c | 6 | ||||
-rw-r--r-- | fs/btrfs/inode.c | 4 |
4 files changed, 13 insertions, 1 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 10b6a75..d48b22f 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1538,6 +1538,7 @@ struct btrfs_fs_info { spinlock_t delayed_iput_lock; struct list_head delayed_iputs; + struct rw_semaphore delayed_iput_sem; /* this protects tree_mod_seq_list */ spinlock_t tree_mod_seq_lock; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 62cd3b6..2ef9a4b 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2487,11 +2487,12 @@ int open_ctree(struct super_block *sb, spin_lock_init(&fs_info->qgroup_op_lock); spin_lock_init(&fs_info->buffer_lock); spin_lock_init(&fs_info->unused_bgs_lock); - mutex_init(&fs_info->unused_bg_unpin_mutex); rwlock_init(&fs_info->tree_mod_log_lock); + mutex_init(&fs_info->unused_bg_unpin_mutex); mutex_init(&fs_info->reloc_mutex); mutex_init(&fs_info->delalloc_root_mutex); seqlock_init(&fs_info->profiles_lock); + init_rwsem(&fs_info->delayed_iput_sem); init_completion(&fs_info->kobj_unregister); INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots); diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index be4a79a..46cb1d41 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3950,6 +3950,12 @@ commit_trans: ret = btrfs_commit_transaction(trans, root); if (ret) return ret; + /* + * make sure that all running delayed iput are + * done + */ + down_write(&root->fs_info->delayed_iput_sem); + up_write(&root->fs_info->delayed_iput_sem); goto again; } else { btrfs_end_transaction(trans, root); diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 141df0c..6ef97c1 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -3111,6 +3111,8 @@ void btrfs_run_delayed_iputs(struct btrfs_root *root) if (empty) return; + down_read(&fs_info->delayed_iput_sem); + spin_lock(&fs_info->delayed_iput_lock); list_splice_init(&fs_info->delayed_iputs, &list); spin_unlock(&fs_info->delayed_iput_lock); @@ -3121,6 +3123,8 @@ void btrfs_run_delayed_iputs(struct btrfs_root *root) iput(delayed->inode); kfree(delayed); } + + up_read(&root->fs_info->delayed_iput_sem); } /* |