From cca83fafa69eb26db458714830b77498b88af8a4 Mon Sep 17 00:00:00 2001

From: Ondřej Vašík <ovasik@redhat.com>

Date: Mon, 14 Sep 2009 13:12:01 +0000

Subject: cp,mv: preserve extended attributes even for read-only files

* src/copy.c (copy_reg): Temporarily set u+rw on the destination file

to allow GNU/Linux to set xattrs.

* tests/misc/xattr: Test that change.

Reported by Ernest N. Mamikonyan.

---

diff --git a/src/copy.c b/src/copy.c

index f3ff5a2..ad2060b 100644

--- a/src/copy.c

+++ b/src/copy.c

@@ -834,6 +834,24 @@ copy_reg (char const *src_name, char const *dst_name,

         }

     }

+  /* To allow copying xattrs on read-only files, temporarily chmod u+rw.

+     This workaround is required as an inode permission check is done

+     by xattr_permission() in fs/xattr.c of the GNU/Linux kernel tree.  */

+  if (x->preserve_xattr)

+    {

+      bool access_changed = false;

+

+      if (!(sb.st_mode & S_IWUSR) && geteuid() != 0)

+        access_changed = fchmod_or_lchmod (dest_desc, dst_name, 0600) == 0;

+

+      if (!copy_attr_by_fd (src_name, source_desc, dst_name, dest_desc, x)

+          && x->require_preserve_xattr)

+        return_val = false;

+

+      if (access_changed)

+        fchmod_or_lchmod (dest_desc, dst_name, dst_mode & ~omitted_permissions);

+    }

+

   if (x->preserve_ownership && ! SAME_OWNER_AND_GROUP (*src_sb, sb))

     {

       switch (set_owner (x, dst_name, dest_desc, src_sb, *new_dst, &sb))

@@ -850,11 +868,6 @@ copy_reg (char const *src_name, char const *dst_name,

   set_author (dst_name, dest_desc, src_sb);

-  if (x->preserve_xattr && ! copy_attr_by_fd (src_name, source_desc,

-                                              dst_name, dest_desc, x)

-      && x->require_preserve_xattr)

-    return_val = false;

-

   if (x->preserve_mode || x->move_mode)

     {

       if (copy_acl (src_name, source_desc, dst_name, dest_desc, src_mode) != 0

diff --git a/tests/misc/xattr b/tests/misc/xattr

index a27e1f6..fcf7ceb 100755

--- a/tests/misc/xattr

+++ b/tests/misc/xattr

@@ -29,7 +29,7 @@ fi

 # Skip this test if cp was built without xattr support:

 touch src dest || framework_failure

-cp --preserve=xattr -n src dest 2>/dev/null \

+cp --preserve=xattr -n src dest \

   || skip_test_ "coreutils built without xattr support"

 # this code was taken from test mv/backup-is-src

@@ -46,13 +46,13 @@ xattr_pair="$xattr_name=\"$xattr_value\""

 # create new file and check its xattrs

 touch a || framework_failure

 getfattr -d a >out_a || skip_test_ "failed to get xattr of file"

-grep -F "$xattr_pair" out_a >/dev/null && framework_failure

+grep -F "$xattr_pair" out_a && framework_failure

 # try to set user xattr on file

 setfattr -n "$xattr_name" -v "$xattr_value" a >out_a \

   || skip_test_ "failed to set xattr of file"

 getfattr -d a >out_a || skip_test_ "failed to get xattr of file"

-grep -F "$xattr_pair" out_a >/dev/null \

+grep -F "$xattr_pair" out_a \

   || skip_test_ "failed to set xattr of file"

 fail=0

@@ -60,36 +60,50 @@ fail=0

 # cp should not preserve xattr by default

 cp a b || fail=1

 getfattr -d b >out_b || skip_test_ "failed to get xattr of file"

-grep -F "$xattr_pair" out_b >/dev/null && fail=1

+grep -F "$xattr_pair" out_b && fail=1

 # test if --preserve=xattr option works

 cp --preserve=xattr a b || fail=1

 getfattr -d b >out_b || skip_test_ "failed to get xattr of file"

-grep -F "$xattr_pair" out_b >/dev/null || fail=1

+grep -F "$xattr_pair" out_b || fail=1

 #test if --preserve=all option works

 cp --preserve=all a c || fail=1

 getfattr -d c >out_c || skip_test_ "failed to get xattr of file"

-grep -F "$xattr_pair" out_c >/dev/null || fail=1

+grep -F "$xattr_pair" out_c || fail=1

 #test if -a option works without any diagnostics

 cp -a a d 2>err && test -s err && fail=1

 getfattr -d d >out_d || skip_test_ "failed to get xattr of file"

-grep -F "$xattr_pair" out_d >/dev/null || fail=1

+grep -F "$xattr_pair" out_d || fail=1

+

+#test if --preserve=xattr works even for files without write access

+chmod a-w a || framework_failure

+rm -f e

+cp --preserve=xattr a e || fail=1

+getfattr -d e >out_e || skip_test_ "failed to get xattr of file"

+grep -F "$xattr_pair" out_e || fail=1

+

+#Ensure that permission bits are preserved, too.

+src_perm=$(stat --format=%a a)

+dst_perm=$(stat --format=%a e)

+test "$dst_perm" = "$src_perm" || fail=1

+

+chmod u+w a || framework_failure

 rm b || framework_failure

 # install should never preserve xattr

 ginstall a b || fail=1

 getfattr -d b >out_b || skip_test_ "failed to get xattr of file"

-grep -F "$xattr_pair" out_b >/dev/null && fail=1

+grep -F "$xattr_pair" out_b && fail=1

 # mv should preserve xattr when renaming within a file system.

 # This is implicitly done by rename () and doesn't need explicit

 # xattr support in mv.

 mv a b || fail=1

 getfattr -d b >out_b || skip_test_ "failed to get xattr of file"

-grep -F "$xattr_pair" out_b >/dev/null || cat >&2 <

+grep -F "$xattr_pair" out_b || cat >&2 <

 =================================================================

 $0: WARNING!!!

 rename () does not preserve extended attributes

@@ -99,18 +113,18 @@ EOF

 # try to set user xattr on file on other partition

 test_mv=1

 touch "$b_other" || framework_failure

-setfattr -n "$xattr_name" -v "$xattr_value" "$b_other" >out_a 2>/dev/null \

+setfattr -n "$xattr_name" -v "$xattr_value" "$b_other" >out_a \

   || test_mv=0

-getfattr -d "$b_other" >out_b 2>/dev/null || test_mv=0

-grep -F "$xattr_pair" out_b >/dev/null || test_mv=0

+getfattr -d "$b_other" >out_b || test_mv=0

+grep -F "$xattr_pair" out_b || test_mv=0

 rm -f "$b_other" || framework_failure

 if test $test_mv -eq 1; then

   # mv should preserve xattr when copying content from one partition to another

   mv b "$b_other" || fail=1

-  getfattr -d "$b_other" >out_b 2>/dev/null ||

+  getfattr -d "$b_other" >out_b ||

     skip_test_ "failed to get xattr of file"

-  grep -F "$xattr_pair" out_b >/dev/null || fail=1

+  grep -F "$xattr_pair" out_b || fail=1

 else

   cat >&2 <

 =================================================================

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