hpfs: make freeing sbi and codetables rcu-delayed
makes ->d_hash() and ->d_compare() safety in RCU mode independent
from vfsmount_lock
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/hpfs/hpfs_fn.h b/fs/hpfs/hpfs_fn.h
index 1b39863..6797bf8 100644
--- a/fs/hpfs/hpfs_fn.h
+++ b/fs/hpfs/hpfs_fn.h
@@ -80,6 +80,7 @@
unsigned sb_c_bitmap; /* current bitmap */
unsigned sb_max_fwd_alloc; /* max forwad allocation */
int sb_timeshift;
+ struct rcu_head rcu;
};
/* Four 512-byte buffers and the 2k block obtained by concatenating them */
diff --git a/fs/hpfs/super.c b/fs/hpfs/super.c
index 4334cda..b8d01ef 100644
--- a/fs/hpfs/super.c
+++ b/fs/hpfs/super.c
@@ -101,18 +101,24 @@
return 0;
}
+static void free_sbi(struct hpfs_sb_info *sbi)
+{
+ kfree(sbi->sb_cp_table);
+ kfree(sbi->sb_bmp_dir);
+ kfree(sbi);
+}
+
+static void lazy_free_sbi(struct rcu_head *rcu)
+{
+ free_sbi(container_of(rcu, struct hpfs_sb_info, rcu));
+}
+
static void hpfs_put_super(struct super_block *s)
{
- struct hpfs_sb_info *sbi = hpfs_sb(s);
-
hpfs_lock(s);
unmark_dirty(s);
hpfs_unlock(s);
-
- kfree(sbi->sb_cp_table);
- kfree(sbi->sb_bmp_dir);
- s->s_fs_info = NULL;
- kfree(sbi);
+ call_rcu(&hpfs_sb(s)->rcu, lazy_free_sbi);
}
unsigned hpfs_count_one_bitmap(struct super_block *s, secno secno)
@@ -485,9 +491,6 @@
}
s->s_fs_info = sbi;
- sbi->sb_bmp_dir = NULL;
- sbi->sb_cp_table = NULL;
-
mutex_init(&sbi->hpfs_mutex);
hpfs_lock(s);
@@ -679,10 +682,7 @@
bail1:
bail0:
hpfs_unlock(s);
- kfree(sbi->sb_bmp_dir);
- kfree(sbi->sb_cp_table);
- s->s_fs_info = NULL;
- kfree(sbi);
+ free_sbi(sbi);
return -EINVAL;
}