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: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 20a917b..6a81b73 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -304,6 +304,11 @@
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 @@
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 @@
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)