linux-kernel - [RFC] scripts/setlocalversion on write-protected source tree

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Date:	Sun, 9 Jun 2013 17:50:49 -0700 (PDT)
From:	Christian Kujau <lists@...dbynature.de>
To:	LKML <linux-kernel@...r.kernel.org>
cc:	nico-linuxsetlocalversion@...ottelius.org
Subject: [RFC] scripts/setlocalversion on write-protected source tree

Hi,

I just stumbled across another[0] issue when scripts/setlocalversion 
operates on a write-protected source tree. Back then[0] the source tree 
was on an read-only NFS share, so "test -w" was introduced before "git 
update-index" was run.

This time, the source tree is on read/write NFS share, but the permissions 
are world-readable and only a specific user (or root) can write. 
Thus, "test -w ." returns "0" and then runs "git update-index", 
producing the following message (on a dirty tree):

  fatal: Unable to create '/usr/local/src/linux-git/.git/index.lock': Permission denied

While it says "fatal", compilation continues just fine.

The patch below adds yet another (clumsy) check before "git 
update-index", but I'm not sure if this is the right way to go.

On a side note, I don't think a kernel compilation should alter the source 
tree (or the .git directory) in any way and I don't see how removing 
"git update-index" could do any harm. The Mercurial and SVN routines in 
scripts/setlocalversion don't have any tree-modifying commands, AFAICS. 
So, maybe the attached patch would be acceptable.

Thoughts?
Christian.

[0] https://patchwork.kernel.org/patch/29718/

diff --git a/scripts/setlocalversion b/scripts/setlocalversion
old mode 100755
new mode 100644
index 84b88f1..2560718
--- a/scripts/setlocalversion
+++ b/scripts/setlocalversion
@@ -72,7 +72,8 @@ scm_version()
 		fi

 		# Update index only on r/w media
-		[ -w . ] && git update-index --refresh --unmerged > /dev/null
+		[ -w . ] && touch .git/index.lock 2>/dev/null && rm -f .git/index.lock && \
+			git update-index --refresh --unmerged > /dev/null

 		# Check for uncommitted changes
 		if git diff-index --name-only HEAD | grep -qv "^scripts/package"; then

-- 
BOFH excuse #359:

YOU HAVE AN I/O ERROR -> Incompetent Operator error
View attachment "setlocalversion_no-update-index.diff" of type "TEXT/x-diff" (492 bytes)