From 24bbcf0442ee04660a5a030efdbb6d03f1c275cb Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Thu, 12 Nov 2009 09:36:34 +0000 Subject: [PATCH] Btrfs: Add delayed iput iput() can trigger new transactions if we are dropping the final reference, so calling it in btrfs_commit_transaction may end up deadlock. This patch adds delayed iput to avoid the issue. Signed-off-by: Yan Zheng Signed-off-by: Chris Mason --- fs/btrfs/ctree.h | 7 +++++- fs/btrfs/disk-io.c | 4 +++ fs/btrfs/extent-tree.c | 8 +++--- fs/btrfs/inode.c | 55 +++++++++++++++++++++++++++++++++++++++-- fs/btrfs/ordered-data.c | 10 +++++--- fs/btrfs/ordered-data.h | 3 ++- fs/btrfs/relocation.c | 4 +-- fs/btrfs/super.c | 4 +-- fs/btrfs/transaction.c | 13 +++++++--- 9 files changed, 90 insertions(+), 18 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index a7cac2148c7c..1983c889bb1c 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -872,6 +872,9 @@ struct btrfs_fs_info { struct list_head dead_roots; struct list_head caching_block_groups; + spinlock_t delayed_iput_lock; + struct list_head delayed_iputs; + atomic_t nr_async_submits; atomic_t async_submit_draining; atomic_t nr_async_bios; @@ -2301,7 +2304,7 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, struct inode *inode, u64 new_size, u32 min_type); -int btrfs_start_delalloc_inodes(struct btrfs_root *root); +int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput); int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end); int btrfs_writepages(struct address_space *mapping, struct writeback_control *wbc); @@ -2341,6 +2344,8 @@ int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode); void btrfs_orphan_cleanup(struct btrfs_root *root); int btrfs_cont_expand(struct inode *inode, loff_t size); int btrfs_invalidate_inodes(struct btrfs_root *root); +void btrfs_add_delayed_iput(struct inode *inode); +void btrfs_run_delayed_iputs(struct btrfs_root *root); extern const struct dentry_operations btrfs_dentry_operations; /* ioctl.c */ diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index c1e59e33f020..009e3bd18f23 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1476,6 +1476,7 @@ static int cleaner_kthread(void *arg) if (!(root->fs_info->sb->s_flags & MS_RDONLY) && mutex_trylock(&root->fs_info->cleaner_mutex)) { + btrfs_run_delayed_iputs(root); btrfs_clean_old_snapshots(root); mutex_unlock(&root->fs_info->cleaner_mutex); } @@ -1605,6 +1606,7 @@ struct btrfs_root *open_ctree(struct super_block *sb, INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC); INIT_LIST_HEAD(&fs_info->trans_list); INIT_LIST_HEAD(&fs_info->dead_roots); + INIT_LIST_HEAD(&fs_info->delayed_iputs); INIT_LIST_HEAD(&fs_info->hashers); INIT_LIST_HEAD(&fs_info->delalloc_inodes); INIT_LIST_HEAD(&fs_info->ordered_operations); @@ -1613,6 +1615,7 @@ struct btrfs_root *open_ctree(struct super_block *sb, spin_lock_init(&fs_info->new_trans_lock); spin_lock_init(&fs_info->ref_cache_lock); spin_lock_init(&fs_info->fs_roots_radix_lock); + spin_lock_init(&fs_info->delayed_iput_lock); init_completion(&fs_info->kobj_unregister); fs_info->tree_root = tree_root; @@ -2386,6 +2389,7 @@ int btrfs_commit_super(struct btrfs_root *root) int ret; mutex_lock(&root->fs_info->cleaner_mutex); + btrfs_run_delayed_iputs(root); btrfs_clean_old_snapshots(root); mutex_unlock(&root->fs_info->cleaner_mutex); diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 4a86508ce473..fcdccfa46004 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -2880,9 +2880,9 @@ static noinline void flush_delalloc_async(struct btrfs_work *work) root = async->root; info = async->info; - btrfs_start_delalloc_inodes(root); + btrfs_start_delalloc_inodes(root, 0); wake_up(&info->flush_wait); - btrfs_wait_ordered_extents(root, 0); + btrfs_wait_ordered_extents(root, 0, 0); spin_lock(&info->lock); info->flushing = 0; @@ -2956,8 +2956,8 @@ static void flush_delalloc(struct btrfs_root *root, return; flush: - btrfs_start_delalloc_inodes(root); - btrfs_wait_ordered_extents(root, 0); + btrfs_start_delalloc_inodes(root, 0); + btrfs_wait_ordered_extents(root, 0, 0); spin_lock(&info->lock); info->flushing = 0; diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 82740a3c628a..168e8c040aab 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -2022,6 +2022,54 @@ zeroit: return -EIO; } +struct delayed_iput { + struct list_head list; + struct inode *inode; +}; + +void btrfs_add_delayed_iput(struct inode *inode) +{ + struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; + struct delayed_iput *delayed; + + if (atomic_add_unless(&inode->i_count, -1, 1)) + return; + + delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL); + delayed->inode = inode; + + spin_lock(&fs_info->delayed_iput_lock); + list_add_tail(&delayed->list, &fs_info->delayed_iputs); + spin_unlock(&fs_info->delayed_iput_lock); +} + +void btrfs_run_delayed_iputs(struct btrfs_root *root) +{ + LIST_HEAD(list); + struct btrfs_fs_info *fs_info = root->fs_info; + struct delayed_iput *delayed; + int empty; + + spin_lock(&fs_info->delayed_iput_lock); + empty = list_empty(&fs_info->delayed_iputs); + spin_unlock(&fs_info->delayed_iput_lock); + if (empty) + return; + + down_read(&root->fs_info->cleanup_work_sem); + spin_lock(&fs_info->delayed_iput_lock); + list_splice_init(&fs_info->delayed_iputs, &list); + spin_unlock(&fs_info->delayed_iput_lock); + + while (!list_empty(&list)) { + delayed = list_entry(list.next, struct delayed_iput, list); + list_del(&delayed->list); + iput(delayed->inode); + kfree(delayed); + } + up_read(&root->fs_info->cleanup_work_sem); +} + /* * This creates an orphan entry for the given inode in case something goes * wrong in the middle of an unlink/truncate. @@ -5568,7 +5616,7 @@ out_fail: * some fairly slow code that needs optimization. This walks the list * of all the inodes with pending delalloc and forces them to disk. */ -int btrfs_start_delalloc_inodes(struct btrfs_root *root) +int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput) { struct list_head *head = &root->fs_info->delalloc_inodes; struct btrfs_inode *binode; @@ -5587,7 +5635,10 @@ int btrfs_start_delalloc_inodes(struct btrfs_root *root) spin_unlock(&root->fs_info->delalloc_lock); if (inode) { filemap_flush(inode->i_mapping); - iput(inode); + if (delay_iput) + btrfs_add_delayed_iput(inode); + else + iput(inode); } cond_resched(); spin_lock(&root->fs_info->delalloc_lock); diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c index 9b16073bb875..b10a49d4bc6a 100644 --- a/fs/btrfs/ordered-data.c +++ b/fs/btrfs/ordered-data.c @@ -352,7 +352,8 @@ int btrfs_remove_ordered_extent(struct inode *inode, * wait for all the ordered extents in a root. This is done when balancing * space between drives. */ -int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only) +int btrfs_wait_ordered_extents(struct btrfs_root *root, + int nocow_only, int delay_iput) { struct list_head splice; struct list_head *cur; @@ -389,7 +390,10 @@ int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only) if (inode) { btrfs_start_ordered_extent(inode, ordered, 1); btrfs_put_ordered_extent(ordered); - iput(inode); + if (delay_iput) + btrfs_add_delayed_iput(inode); + else + iput(inode); } else { btrfs_put_ordered_extent(ordered); } @@ -447,7 +451,7 @@ again: btrfs_wait_ordered_range(inode, 0, (u64)-1); else filemap_flush(inode->i_mapping); - iput(inode); + btrfs_add_delayed_iput(inode); } cond_resched(); diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h index 4fa20398aec1..1fe1282ef47c 100644 --- a/fs/btrfs/ordered-data.h +++ b/fs/btrfs/ordered-data.h @@ -153,9 +153,10 @@ btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset); int btrfs_ordered_update_i_size(struct inode *inode, u64 offset, struct btrfs_ordered_extent *ordered); int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, u32 *sum); -int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only); int btrfs_run_ordered_operations(struct btrfs_root *root, int wait); int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *inode); +int btrfs_wait_ordered_extents(struct btrfs_root *root, + int nocow_only, int delay_iput); #endif diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index f2aa53d2f944..a9728680eca8 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -3541,8 +3541,8 @@ int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start) (unsigned long long)rc->block_group->key.objectid, (unsigned long long)rc->block_group->flags); - btrfs_start_delalloc_inodes(fs_info->tree_root); - btrfs_wait_ordered_extents(fs_info->tree_root, 0); + btrfs_start_delalloc_inodes(fs_info->tree_root, 0); + btrfs_wait_ordered_extents(fs_info->tree_root, 0, 0); while (1) { rc->extents_found = 0; diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 752a5463bf53..270cc96b9a43 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -405,8 +405,8 @@ int btrfs_sync_fs(struct super_block *sb, int wait) return 0; } - btrfs_start_delalloc_inodes(root); - btrfs_wait_ordered_extents(root, 0); + btrfs_start_delalloc_inodes(root, 0); + btrfs_wait_ordered_extents(root, 0, 0); trans = btrfs_start_transaction(root, 1); ret = btrfs_commit_transaction(trans, root); diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 728e8fe5d2cc..75b31caade29 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -333,6 +333,9 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans, memset(trans, 0, sizeof(*trans)); kmem_cache_free(btrfs_trans_handle_cachep, trans); + if (throttle) + btrfs_run_delayed_iputs(root); + return 0; } @@ -991,11 +994,11 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, mutex_unlock(&root->fs_info->trans_mutex); if (flush_on_commit) { - btrfs_start_delalloc_inodes(root); - ret = btrfs_wait_ordered_extents(root, 0); + btrfs_start_delalloc_inodes(root, 1); + ret = btrfs_wait_ordered_extents(root, 0, 1); BUG_ON(ret); } else if (snap_pending) { - ret = btrfs_wait_ordered_extents(root, 1); + ret = btrfs_wait_ordered_extents(root, 0, 1); BUG_ON(ret); } @@ -1113,6 +1116,10 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, current->journal_info = NULL; kmem_cache_free(btrfs_trans_handle_cachep, trans); + + if (current != root->fs_info->transaction_kthread) + btrfs_run_delayed_iputs(root); + return ret; } -- 2.25.1