[PATCH 20/21] namei: move saved_nd pointer into struct nameidata

From: Al Viro
Date: Wed May 13 2015 - 18:29:25 EST


From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

these guys are always declared next to each other; might as well put
the former (pointer to previous instance) into the latter and simplify
the calling conventions for {set,restore}_nameidata()

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
fs/namei.c | 46 ++++++++++++++++++++++++----------------------
1 file changed, 24 insertions(+), 22 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 23dd9e8..dead60d 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -498,10 +498,8 @@ struct nameidata {
struct qstr last;
struct path root;
struct inode *inode; /* path.dentry.d_inode */
- struct filename *name;
- int dfd;
unsigned int flags;
- unsigned seq, m_seq, root_seq;
+ unsigned seq, m_seq;
int last_type;
unsigned depth;
int total_link_count;
@@ -512,23 +510,26 @@ struct nameidata {
struct inode *inode;
unsigned seq;
} *stack, internal[EMBEDDED_LEVELS];
+ struct filename *name;
+ struct nameidata *saved;
+ unsigned root_seq;
+ int dfd;
};

-static struct nameidata *set_nameidata(struct nameidata *p, int dfd,
- struct filename *name)
+static void set_nameidata(struct nameidata *p, int dfd, struct filename *name)
{
struct nameidata *old = current->nameidata;
p->stack = p->internal;
p->dfd = dfd;
p->name = name;
p->total_link_count = old ? old->total_link_count : 0;
+ p->saved = old;
current->nameidata = p;
- return old;
}

-static void restore_nameidata(struct nameidata *old)
+static void restore_nameidata(void)
{
- struct nameidata *now = current->nameidata;
+ struct nameidata *now = current->nameidata, *old = now->saved;

current->nameidata = old;
if (old)
@@ -2118,14 +2119,14 @@ static int filename_lookup(int dfd, struct filename *name, unsigned flags,
struct path *path, struct path *root)
{
int retval;
- struct nameidata nd, *saved_nd;
+ struct nameidata nd;
if (IS_ERR(name))
return PTR_ERR(name);
- saved_nd = set_nameidata(&nd, dfd, name);
if (unlikely(root)) {
nd.root = *root;
flags |= LOOKUP_ROOT;
}
+ set_nameidata(&nd, dfd, name);
retval = path_lookupat(&nd, flags | LOOKUP_RCU, path);
if (unlikely(retval == -ECHILD))
retval = path_lookupat(&nd, flags, path);
@@ -2134,7 +2135,7 @@ static int filename_lookup(int dfd, struct filename *name, unsigned flags,

if (likely(!retval))
audit_inode(name, path->dentry, flags & LOOKUP_PARENT);
- restore_nameidata(saved_nd);
+ restore_nameidata();
putname(name);
return retval;
}
@@ -2164,11 +2165,11 @@ static struct filename *filename_parentat(int dfd, struct filename *name,
struct qstr *last, int *type)
{
int retval;
- struct nameidata nd, *saved_nd;
+ struct nameidata nd;

if (IS_ERR(name))
return name;
- saved_nd = set_nameidata(&nd, dfd, name);
+ set_nameidata(&nd, dfd, name);
retval = path_parentat(&nd, flags | LOOKUP_RCU, parent);
if (unlikely(retval == -ECHILD))
retval = path_parentat(&nd, flags, parent);
@@ -2182,7 +2183,7 @@ static struct filename *filename_parentat(int dfd, struct filename *name,
putname(name);
name = ERR_PTR(retval);
}
- restore_nameidata(saved_nd);
+ restore_nameidata();
return name;
}

@@ -2443,11 +2444,11 @@ static int
filename_mountpoint(int dfd, struct filename *name, struct path *path,
unsigned int flags)
{
- struct nameidata nd, *saved;
+ struct nameidata nd;
int error;
if (IS_ERR(name))
return PTR_ERR(name);
- saved = set_nameidata(&nd, dfd, name);
+ set_nameidata(&nd, dfd, name);
error = path_mountpoint(&nd, flags | LOOKUP_RCU, path);
if (unlikely(error == -ECHILD))
error = path_mountpoint(&nd, flags, path);
@@ -2455,7 +2456,7 @@ filename_mountpoint(int dfd, struct filename *name, struct path *path,
error = path_mountpoint(&nd, flags | LOOKUP_REVAL, path);
if (likely(!error))
audit_inode(name, path->dentry, 0);
- restore_nameidata(saved);
+ restore_nameidata();
putname(name);
return error;
}
@@ -3325,23 +3326,24 @@ out2:
struct file *do_filp_open(int dfd, struct filename *pathname,
const struct open_flags *op)
{
- struct nameidata nd, *saved_nd = set_nameidata(&nd, dfd, pathname);
+ struct nameidata nd;
int flags = op->lookup_flags;
struct file *filp;

+ set_nameidata(&nd, dfd, pathname);
filp = path_openat(&nd, op, flags | LOOKUP_RCU);
if (unlikely(filp == ERR_PTR(-ECHILD)))
filp = path_openat(&nd, op, flags);
if (unlikely(filp == ERR_PTR(-ESTALE)))
filp = path_openat(&nd, op, flags | LOOKUP_REVAL);
- restore_nameidata(saved_nd);
+ restore_nameidata();
return filp;
}

struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
const char *name, const struct open_flags *op)
{
- struct nameidata nd, *saved_nd;
+ struct nameidata nd;
struct file *file;
struct filename *filename;
int flags = op->lookup_flags | LOOKUP_ROOT;
@@ -3356,13 +3358,13 @@ struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
if (unlikely(IS_ERR(filename)))
return ERR_CAST(filename);

- saved_nd = set_nameidata(&nd, -1, filename);
+ set_nameidata(&nd, -1, filename);
file = path_openat(&nd, op, flags | LOOKUP_RCU);
if (unlikely(file == ERR_PTR(-ECHILD)))
file = path_openat(&nd, op, flags);
if (unlikely(file == ERR_PTR(-ESTALE)))
file = path_openat(&nd, op, flags | LOOKUP_REVAL);
- restore_nameidata(saved_nd);
+ restore_nameidata();
putname(filename);
return file;
}
--
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/