vfs: make it possible to access the dentry hash/len as one 64-bit entry
This allows comparing hash and len in one operation on 64-bit
architectures. Right now only __d_lookup_rcu() takes advantage of this,
since that is the case we care most about.
The use of anonymous struct/unions hides the alternate 64-bit approach
from most users, the exception being a few cases where we initialize a
'struct qstr' with a static initializer. This makes the problematic
cases use a new QSTR_INIT() helper function for that (but initializing
just the name pointer with a "{ .name = xyzzy }" initializer remains
valid, as does just copying another qstr structure).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/libfs.c b/fs/libfs.c
index 18d08f5..f86ec27 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -68,7 +68,7 @@
int dcache_dir_open(struct inode *inode, struct file *file)
{
- static struct qstr cursor_name = {.len = 1, .name = "."};
+ static struct qstr cursor_name = QSTR_INIT(".", 1);
file->private_data = d_alloc(file->f_path.dentry, &cursor_name);
@@ -225,7 +225,7 @@
struct super_block *s = sget(fs_type, NULL, set_anon_super, NULL);
struct dentry *dentry;
struct inode *root;
- struct qstr d_name = {.name = name, .len = strlen(name)};
+ struct qstr d_name = QSTR_INIT(name, strlen(name));
if (IS_ERR(s))
return ERR_CAST(s);