linux-kernel - [PATCH] xfs: set inode size after creating symlink

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Message-Id: <20210121151912.4429-1-jeffrey.mitchell@starlab.io>
Date:   Thu, 21 Jan 2021 09:19:12 -0600
From:   Jeffrey Mitchell <jeffrey.mitchell@...rlab.io>
To:     "Darrick J . Wong" <djwong@...nel.org>
Cc:     linux-xfs@...r.kernel.org, linux-kernel@...r.kernel.org,
        Jeffrey Mitchell <jeffrey.mitchell@...rlab.io>
Subject: [PATCH] xfs: set inode size after creating symlink

When XFS creates a new symlink, it writes its size to disk but not to the
VFS inode. This causes i_size_read() to return 0 for that symlink until
it is re-read from disk, for example when the system is rebooted.

I found this inconsistency while protecting directories with eCryptFS.
The command "stat path/to/symlink/in/ecryptfs" will report "Size: 0" if
the symlink was created after the last reboot on an XFS root.

Call i_size_write() in xfs_symlink()

Signed-off-by: Jeffrey Mitchell <jeffrey.mitchell@...rlab.io>
---
 fs/xfs/xfs_symlink.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/xfs/xfs_symlink.c b/fs/xfs/xfs_symlink.c
index 1f43fd7f3209..c835827ae389 100644
--- a/fs/xfs/xfs_symlink.c
+++ b/fs/xfs/xfs_symlink.c
@@ -300,6 +300,7 @@ xfs_symlink(
 		}
 		ASSERT(pathlen == 0);
 	}
+	i_size_write(VFS_I(ip), ip->i_d.di_size);

 	/*
 	 * Create the directory entry for the symlink.
-- 
2.25.1