nilfs2: fix lockdep recursive locking warning on bmap
The bmap semaphore of DAT file can be held while a bmap of other files
is locked. This has caused the following false detection of lockdep
check:
mount.nilfs2/4667 is trying to acquire lock:
(&bmap->b_sem){..--}, at: [<d0c6c4b4>] nilfs_bmap_lookup_at_level+0x1a/0x74 [nilfs2]
but task is already holding lock:
(&bmap->b_sem){..--}, at: [<d0c6c4b4>] nilfs_bmap_lookup_at_level+0x1a/0x74 [nilfs2]
This will fix the false detection by distinguishing semaphores of the
DAT and other files.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
diff --git a/fs/nilfs2/bmap.c b/fs/nilfs2/bmap.c
index 24638e0..064279e 100644
--- a/fs/nilfs2/bmap.c
+++ b/fs/nilfs2/bmap.c
@@ -688,6 +688,8 @@
.bpop_translate = NULL,
};
+static struct lock_class_key nilfs_bmap_dat_lock_key;
+
/**
* nilfs_bmap_read - read a bmap from an inode
* @bmap: bmap
@@ -715,6 +717,7 @@
bmap->b_pops = &nilfs_bmap_ptr_ops_p;
bmap->b_last_allocated_key = 0; /* XXX: use macro */
bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
+ lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
break;
case NILFS_CPFILE_INO:
case NILFS_SUFILE_INO:
@@ -772,6 +775,7 @@
{
memcpy(gcbmap, bmap, sizeof(union nilfs_bmap_union));
init_rwsem(&gcbmap->b_sem);
+ lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
gcbmap->b_inode = &NILFS_BMAP_I(gcbmap)->vfs_inode;
}
@@ -779,5 +783,6 @@
{
memcpy(bmap, gcbmap, sizeof(union nilfs_bmap_union));
init_rwsem(&bmap->b_sem);
+ lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
}