From 6f7de19ed3d4d3526ca5eca428009f97cf969c2f Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu@suse.com>
Date: Wed, 27 Jun 2018 18:19:55 +0800
Subject: [PATCH 1/3] btrfs: quota: Set rescan progress to (u64)-1 if we hit
 last leaf

Commit ff3d27a048d9 ("btrfs: qgroup: Finish rescan when hit the last leaf
of extent tree") added a new exit for rescan finish.

However after finishing quota rescan, we set
fs_info->qgroup_rescan_progress to (u64)-1 before we exit through the
original exit path.
While we missed that assignment of (u64)-1 in the new exit path.

The end result is, the quota status item doesn't have the same value.
(-1 vs the last bytenr + 1)
Although it doesn't affect quota accounting, it's still better to keep
the original behavior.

Reported-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Fixes: ff3d27a048d9 ("btrfs: qgroup: Finish rescan when hit the last leaf of extent tree")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/qgroup.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 1874a6d2e6f5..99f2b9ce0f15 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -2680,8 +2680,10 @@ out:
 		free_extent_buffer(scratch_leaf);
 	}
 
-	if (done && !ret)
+	if (done && !ret) {
 		ret = 1;
+		fs_info->qgroup_rescan_progress.objectid = (u64)-1;
+	}
 	return ret;
 }
 

From 717beb96d969561cff53aad2f09547db20ee6ffd Mon Sep 17 00:00:00 2001
From: Chris Mason <clm@fb.com>
Date: Mon, 25 Jun 2018 10:03:41 -0700
Subject: [PATCH 2/3] Btrfs: fix regression in btrfs_page_mkwrite() from
 vm_fault_t conversion

The vm_fault_t conversion commit introduced a ret2 variable for tracking
the integer return values from internal btrfs functions.  It was
sometimes returning VM_FAULT_LOCKED for pages that were actually invalid
and had been removed from the radix.  Something like this:

    ret2 = btrfs_delalloc_reserve_space() // returns zero on success

    lock_page(page)
    if (page->mapping != inode->i_mapping)
	goto out_unlock;

...

out_unlock:
    if (!ret2) {
	    ...
	    return VM_FAULT_LOCKED;
    }

This ends up triggering this WARNING in btrfs_destroy_inode()
    WARN_ON(BTRFS_I(inode)->block_rsv.size);

xfstests generic/095 was able to reliably reproduce the errors.

Since out_unlock: is only used for errors, this fix moves it below the
if (!ret2) check we use to return VM_FAULT_LOCKED for success.

Fixes: a528a2415087 (btrfs: change return type of btrfs_page_mkwrite to vm_fault_t)
Signed-off-by: Chris Mason <clm@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/inode.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index a6bf9e2ff68f..f21f4223d03b 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -9005,13 +9005,14 @@ again:
 
 	unlock_extent_cached(io_tree, page_start, page_end, &cached_state);
 
-out_unlock:
 	if (!ret2) {
 		btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE, true);
 		sb_end_pagefault(inode->i_sb);
 		extent_changeset_free(data_reserved);
 		return VM_FAULT_LOCKED;
 	}
+
+out_unlock:
 	unlock_page(page);
 out:
 	btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE, (ret != 0));

From e4e7ede739f7fb468686dfffa2d1e35dca35bacd Mon Sep 17 00:00:00 2001
From: Filipe Manana <fdmanana@suse.com>
Date: Wed, 27 Jun 2018 00:43:15 +0100
Subject: [PATCH 3/3] Btrfs: fix mount failure when qgroup rescan is in
 progress

If a power failure happens while the qgroup rescan kthread is running,
the next mount operation will always fail. This is because of a recent
regression that makes qgroup_rescan_init() incorrectly return -EINVAL
when we are mounting the filesystem (through btrfs_read_qgroup_config()).
This causes the -EINVAL error to be returned regardless of any qgroup
flags being set instead of returning the error only when neither of
the flags BTRFS_QGROUP_STATUS_FLAG_RESCAN nor BTRFS_QGROUP_STATUS_FLAG_ON
are set.

A test case for fstests follows up soon.

Fixes: 9593bf49675e ("btrfs: qgroup: show more meaningful qgroup_rescan_init error message")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/qgroup.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 99f2b9ce0f15..c25dc47210a3 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -2786,13 +2786,20 @@ qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
 
 	if (!init_flags) {
 		/* we're resuming qgroup rescan at mount time */
-		if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN))
+		if (!(fs_info->qgroup_flags &
+		      BTRFS_QGROUP_STATUS_FLAG_RESCAN)) {
 			btrfs_warn(fs_info,
 			"qgroup rescan init failed, qgroup is not enabled");
-		else if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
+			ret = -EINVAL;
+		} else if (!(fs_info->qgroup_flags &
+			     BTRFS_QGROUP_STATUS_FLAG_ON)) {
 			btrfs_warn(fs_info,
 			"qgroup rescan init failed, qgroup rescan is not queued");
-		return -EINVAL;
+			ret = -EINVAL;
+		}
+
+		if (ret)
+			return ret;
 	}
 
 	mutex_lock(&fs_info->qgroup_rescan_lock);