linux-kernel - [PATCH 1/2] Btrfs: fix permissions of empty files not affected by umask

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Date:	Thu, 29 Nov 2012 19:40:08 -0800
From:	Filipe Brandenburger <filbranden@...gle.com>
To:	Chris Mason <chris.mason@...ionio.com>, linux-btrfs@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org,
	Filipe Brandenburger <filbranden@...gle.com>
Subject: [PATCH 1/2] Btrfs: fix permissions of empty files not affected by umask

When a new file is created with btrfs_create(), the inode will initially be
created with permissions 0666 and later on in btrfs_init_acl() it will be
adapted to mask out the umask bits. The problem is that this change won't make
it into the btrfs_inode unless there's another change to the inode (e.g. writing
content changing the size or touching the file changing the mtime.)

This fix adds a call to btrfs_update_inode() to btrfs_create() to make sure that
the change will not get lost if the in-memory inode is flushed before other
changes are made to the file.

Signed-off-by: Filipe Brandenburger <filbranden@...gle.com>
---
 fs/btrfs/inode.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 95542a1..caf9d76 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4996,6 +4996,12 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
 		goto out_unlock;
 	}

+	err = btrfs_update_inode(trans, root, inode);
+	if (err) {
+		drop_inode = 1;
+		goto out_unlock;
+	}
+
 	/*
 	* If the active LSM wants to access the inode during
 	* d_instantiate it needs these. Smack checks to see
-- 
1.7.11.7

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