linux-ext4 - Re: e2fsprogs and fast symlink

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Date:	Mon, 24 Mar 2008 17:07:47 +0530
From:	"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
To:	Theodore Tso <tytso@....edu>, Eric Sandeen <sandeen@...hat.com>
Cc:	ext4 development <linux-ext4@...r.kernel.org>
Subject: Re: e2fsprogs and fast symlink

On Fri, Mar 21, 2008 at 05:12:34PM +0530, Aneesh Kumar K.V wrote:
> Hi Ted,
> 
> The below test case fails x86
> #ln -s sfdajsfsdsdfskjdgfkshdfkshdfkgdsjdsjdhsdfdafdsgakfasdgfsjksdsdsdfsd p 
> #sync
> #rm p
> root@...3b165:~# /usr/local/e2fsprogs/sbin/e2fsck  -f  /dev/sda5
> e2fsck 1.40.8 (13-Mar-2008)
> Pass 1: Checking inodes, blocks, and sizes
> Fast symlink 12 has EXTENT_FL set.  Clear<y>? 
> 
> ie because after deleting the file we have
> debugfs:  stat <12>
> Inode: 12   Type: symlink    Mode:  0777   Flags: 0x80000   Generation:
> 25346603
> User:     0   Group:     0   Size: 0
> File ACL: 0    Directory ACL: 0
> Links: 0   Blockcount: 0
> Fragment:  Address: 0    Number: 0    Size: 0
> ctime: 0x47e39ea3 -- Fri Mar 21 11:40:19 2008
> atime: 0x47e39e9e -- Fri Mar 21 11:40:14 2008
> mtime: 0x47e39e9a -- Fri Mar 21 11:40:10 2008
> dtime: 0x47e39ea3 -- Fri Mar 21 11:40:19 2008
> Size of extra inode fields: 28
> Fast_link_dest: 
> 
> 
> shouldn't e2fsprogs also look at whether the inode is in use ?

Or something like this in kernel ?

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 50d700f..cc124b1 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -204,6 +204,14 @@ void ext4_delete_inode (struct inode * inode)
 	inode->i_size = 0;
 	if (inode->i_blocks)
 		ext4_truncate(inode);
+
+	/*
+	 * In case of link clear the extent flag. Fast symlinks are not
+	 * stored in extent format we use i_blocks count to determine
+	 * whether it is fast link or not.
+	 */
+	if (S_ISLNK(inode->i_mode))
+		 EXT4_I(inode)->i_flags &= ~EXT4_EXTENTS_FL;
 	/*
 	 * Kill off the orphan record which ext4_truncate created.
 	 * AKPM: I think this can be inside the above `if'.
--
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