x86/smpboot: Init apic mapping before usage

[cascardo/linux.git] / fs / super.c

diff --git a/fs/super.c b/fs/super.c
index c2ff475..c183835 100644 (file)
--- a/fs/super.c
+++ b/fs/super.c
@@ -1269,25 +1269,34 @@ EXPORT_SYMBOL(__sb_start_write);
 static void sb_wait_write(struct super_block *sb, int level)
 {
        percpu_down_write(sb->s_writers.rw_sem + level-1);
-       /*
-        * We are going to return to userspace and forget about this lock, the
-        * ownership goes to the caller of thaw_super() which does unlock.
-        *
-        * FIXME: we should do this before return from freeze_super() after we
-        * called sync_filesystem(sb) and s_op->freeze_fs(sb), and thaw_super()
-        * should re-acquire these locks before s_op->unfreeze_fs(sb). However
-        * this leads to lockdep false-positives, so currently we do the early
-        * release right after acquire.
-        */
-       percpu_rwsem_release(sb->s_writers.rw_sem + level-1, 0, _THIS_IP_);
 }
 
-static void sb_freeze_unlock(struct super_block *sb)
+/*
+ * We are going to return to userspace and forget about these locks, the
+ * ownership goes to the caller of thaw_super() which does unlock().
+ */
+static void lockdep_sb_freeze_release(struct super_block *sb)
+{
+       int level;
+
+       for (level = SB_FREEZE_LEVELS - 1; level >= 0; level--)
+               percpu_rwsem_release(sb->s_writers.rw_sem + level, 0, _THIS_IP_);
+}
+
+/*
+ * Tell lockdep we are holding these locks before we call ->unfreeze_fs(sb).
+ */
+static void lockdep_sb_freeze_acquire(struct super_block *sb)
 {
        int level;
 
        for (level = 0; level < SB_FREEZE_LEVELS; ++level)
                percpu_rwsem_acquire(sb->s_writers.rw_sem + level, 0, _THIS_IP_);
+}
+
+static void sb_freeze_unlock(struct super_block *sb)
+{
+       int level;
 
        for (level = SB_FREEZE_LEVELS - 1; level >= 0; level--)
                percpu_up_write(sb->s_writers.rw_sem + level);
@@ -1379,10 +1388,11 @@ int freeze_super(struct super_block *sb)
                }
        }
        /*
-        * This is just for debugging purposes so that fs can warn if it
-        * sees write activity when frozen is set to SB_FREEZE_COMPLETE.
+        * For debugging purposes so that fs can warn if it sees write activity
+        * when frozen is set to SB_FREEZE_COMPLETE, and for thaw_super().
         */
        sb->s_writers.frozen = SB_FREEZE_COMPLETE;
+       lockdep_sb_freeze_release(sb);
        up_write(&sb->s_umount);
        return 0;
 }
@@ -1399,7 +1409,7 @@ int thaw_super(struct super_block *sb)
        int error;
 
        down_write(&sb->s_umount);
-       if (sb->s_writers.frozen == SB_UNFROZEN) {
+       if (sb->s_writers.frozen != SB_FREEZE_COMPLETE) {
                up_write(&sb->s_umount);
                return -EINVAL;
        }
@@ -1409,11 +1419,14 @@ int thaw_super(struct super_block *sb)
                goto out;
        }
 
+       lockdep_sb_freeze_acquire(sb);
+
        if (sb->s_op->unfreeze_fs) {
                error = sb->s_op->unfreeze_fs(sb);
                if (error) {
                        printk(KERN_ERR
                                "VFS:Filesystem thaw failed\n");
+                       lockdep_sb_freeze_release(sb);
                        up_write(&sb->s_umount);
                        return error;
                }