Commit 769ec6e5 authored by Jaegeuk Kim's avatar Jaegeuk Kim
Browse files

f2fs: call radix_tree_preload before radix_tree_insert 



This patch tries to fix:

 BUG: using smp_processor_id() in preemptible [00000000] code: f2fs_gc-254:0/384
  (radix_tree_node_alloc+0x14/0x74) from [<c033d8a0>] (radix_tree_insert+0x110/0x200)
  (radix_tree_insert+0x110/0x200) from [<c02e8264>] (gc_data_segment+0x340/0x52c)
  (gc_data_segment+0x340/0x52c) from [<c02e8658>] (f2fs_gc+0x208/0x400)
  (f2fs_gc+0x208/0x400) from [<c02e8a98>] (gc_thread_func+0x248/0x28c)
  (gc_thread_func+0x248/0x28c) from [<c0139944>] (kthread+0xa0/0xac)
  (kthread+0xa0/0xac) from [<c0105ef8>] (ret_from_fork+0x14/0x3c)

The reason is that f2fs calls radix_tree_insert under enabled preemption.
So, before calling it, we need to call radix_tree_preload.

Otherwise, we should use _GFP_WAIT for the radix tree, and use mutex or
semaphore to cover the radix tree operations.

Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 8b26ef98

fs/f2fs/checkpoint.c

+8 −0
Original line number Diff line number Diff line
@@ -304,6 +304,11 @@ static void __add_ino_entry(struct f2fs_sb_info *sbi, nid_t ino, int type) 
	struct inode_management *im = &sbi->im[type];

	struct ino_entry *e;

retry:

	if (radix_tree_preload(GFP_NOFS)) {

		cond_resched();

		goto retry;

	}



	spin_lock(&im->ino_lock);



	e = radix_tree_lookup(&im->ino_root, ino);
@@ -311,11 +316,13 @@ retry: 
		e = kmem_cache_alloc(ino_entry_slab, GFP_ATOMIC);

		if (!e) {

			spin_unlock(&im->ino_lock);

			radix_tree_preload_end();

			goto retry;

		}

		if (radix_tree_insert(&im->ino_root, ino, e)) {

			spin_unlock(&im->ino_lock);

			kmem_cache_free(ino_entry_slab, e);

			radix_tree_preload_end();

			goto retry;

		}

		memset(e, 0, sizeof(struct ino_entry));
@@ -326,6 +333,7 @@ retry: 
			im->ino_num++;

	}

	spin_unlock(&im->ino_lock);

	radix_tree_preload_end();

}



static void __remove_ino_entry(struct f2fs_sb_info *sbi, nid_t ino, int type)

fs/f2fs/gc.c

+2 −4
Original line number Diff line number Diff line
@@ -351,7 +351,6 @@ static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino) 
static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)

{

	struct inode_entry *new_ie;

	int ret;



	if (inode == find_gc_inode(gc_list, inode->i_ino)) {

		iput(inode);
@@ -361,8 +360,7 @@ retry: 
	new_ie = f2fs_kmem_cache_alloc(winode_slab, GFP_NOFS);

	new_ie->inode = inode;



	ret = radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);

	if (ret) {

	if (radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie)) {

		kmem_cache_free(winode_slab, new_ie);

		goto retry;

	}
@@ -703,7 +701,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi) 
	struct cp_control cpc;

	struct gc_inode_list gc_list = {

		.ilist = LIST_HEAD_INIT(gc_list.ilist),

		.iroot = RADIX_TREE_INIT(GFP_ATOMIC),

		.iroot = RADIX_TREE_INIT(GFP_NOFS),

	};



	cpc.reason = test_opt(sbi, FASTBOOT) ? CP_UMOUNT : CP_SYNC;

fs/f2fs/node.c

+9 −2
Original line number Diff line number Diff line
@@ -1447,15 +1447,22 @@ static int add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build) 
	i->nid = nid;

	i->state = NID_NEW;



	if (radix_tree_preload(GFP_NOFS)) {

		kmem_cache_free(free_nid_slab, i);

		return 0;

	}



	spin_lock(&nm_i->free_nid_list_lock);

	if (radix_tree_insert(&nm_i->free_nid_root, i->nid, i)) {

		spin_unlock(&nm_i->free_nid_list_lock);

		radix_tree_preload_end();

		kmem_cache_free(free_nid_slab, i);

		return 0;

	}

	list_add_tail(&i->list, &nm_i->free_nid_list);

	nm_i->fcnt++;

	spin_unlock(&nm_i->free_nid_list_lock);

	radix_tree_preload_end();

	return 1;

}
@@ -1994,8 +2001,8 @@ static int init_node_manager(struct f2fs_sb_info *sbi) 


	INIT_RADIX_TREE(&nm_i->free_nid_root, GFP_ATOMIC);

	INIT_LIST_HEAD(&nm_i->free_nid_list);

	INIT_RADIX_TREE(&nm_i->nat_root, GFP_ATOMIC);

	INIT_RADIX_TREE(&nm_i->nat_set_root, GFP_ATOMIC);

	INIT_RADIX_TREE(&nm_i->nat_root, GFP_NOIO);

	INIT_RADIX_TREE(&nm_i->nat_set_root, GFP_NOIO);

	INIT_LIST_HEAD(&nm_i->nat_entries);



	mutex_init(&nm_i->build_lock);

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