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

[Christian Kujau]

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 errordiff --git a/scripts/setlocalversion b/scripts/setlocalversion
index 84b88f1..d105a44 100755
--- a/scripts/setlocalversion
+++ b/scripts/setlocalversion
@@ -71,9 +71,6 @@ scm_version()
 			printf -- '-svn%s' "`git svn find-rev $head`"
 		fi
 
-		# Update index only on r/w media
-		[ -w . ] && git update-index --refresh --unmerged > /dev/null
-
 		# Check for uncommitted changes
 		if git diff-index --name-only HEAD | grep -qv "^scripts/package"; then
 			printf '%s' -dirty