[PATCH] vfs: workaround gcc <4.6 build error in link_path_walk()

From: James Hogan
Date: Tue Sep 16 2014 - 08:07:58 EST


Commit d6bb3e9075bb (vfs: simplify and shrink stack frame of
link_path_walk()) introduced build problems with GCC versions older than
4.6 due to the initialisation of a member of an anonymous union in
struct qstr without enclosing braces.

This hits GCC bug 10676 [1] (which was fixed in GCC 4.6 by [2]), and
causes the following build error:
fs/namei.c: In function 'link_path_walk':
fs/namei.c:1778: error: unknown field 'hash_len' specified in initializer

This is worked around by adding explicit braces.

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=10676
[2] https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=159206

Fixes: d6bb3e9075bb (vfs: simplify and shrink stack frame of link_path_walk())
Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: linux-fsdevel@xxxxxxxxxxxxxxx
Cc: linux-metag@xxxxxxxxxxxxxxx
---
At least for metag it's feasible to fix the compiler, since backporting
the fix to GCC 4.2.4 isn't actually very difficult. I don't know about
other users of GCC <4.6 though.
---
fs/namei.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/namei.c b/fs/namei.c
index 01d03892316c..a7b05bf82d31 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1775,7 +1775,7 @@ static int link_path_walk(const char *name, struct nameidata *nd)
struct dentry *parent = nd->path.dentry;
nd->flags &= ~LOOKUP_JUMPED;
if (unlikely(parent->d_flags & DCACHE_OP_HASH)) {
- struct qstr this = { .hash_len = hash_len, .name = name };
+ struct qstr this = { { .hash_len = hash_len }, .name = name };
err = parent->d_op->d_hash(parent, &this);
if (err < 0)
break;
--
1.8.5.5

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