[patch 09/10] Use struct path in fs_struct

From: jblunck
Date: Thu Sep 27 2007 - 10:12:05 EST

* Use struct path in fs_struct.

Signed-off-by: Andreas Gruenbacher <agruen@xxxxxxx>
Signed-off-by: Jan Blunck <jblunck@xxxxxxx>
---
fs/dcache.c | 31 +++++++++----------------
fs/namei.c | 47 +++++++++++++-------------------------
fs/namespace.c | 56 +++++++++++++++++++---------------------------
fs/proc/base.c | 8 +++---
include/linux/fs_struct.h | 6 +---
init/do_mounts.c | 6 ++--
kernel/auditsc.c | 4 +--
kernel/exit.c | 12 +++------
kernel/fork.c | 17 +++++--------
9 files changed, 75 insertions(+), 112 deletions(-)

Index: b/fs/dcache.c
===================================================================
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1854,8 +1854,7 @@ char * d_path(struct dentry *dentry, str
char *buf, int buflen)
{
char *res;
- struct vfsmount *rootmnt;
- struct dentry *root;
+ struct path root;

/*
* We have various synthetic filesystems that never get mounted. On
@@ -1868,14 +1867,12 @@ char * d_path(struct dentry *dentry, str
return dentry->d_op->d_dname(dentry, buf, buflen);

read_lock(&current->fs->lock);
- rootmnt = mntget(current->fs->rootmnt);
- root = dget(current->fs->root);
+ root = *path_get(&current->fs->root);
read_unlock(&current->fs->lock);
spin_lock(&dcache_lock);
- res = __d_path(dentry, vfsmnt, root, rootmnt, buf, buflen);
+ res = __d_path(dentry, vfsmnt, root.dentry, root.mnt, buf, buflen);
spin_unlock(&dcache_lock);
- dput(root);
- mntput(rootmnt);
+ path_put(&root);
return res;
}

@@ -1921,28 +1918,26 @@ char *dynamic_dname(struct dentry *dentr
asmlinkage long sys_getcwd(char __user *buf, unsigned long size)
{
int error;
- struct vfsmount *pwdmnt, *rootmnt;
- struct dentry *pwd, *root;
+ struct path pwd, root;
char *page = (char *) __get_free_page(GFP_USER);

if (!page)
return -ENOMEM;

read_lock(&current->fs->lock);
- pwdmnt = mntget(current->fs->pwdmnt);
- pwd = dget(current->fs->pwd);
- rootmnt = mntget(current->fs->rootmnt);
- root = dget(current->fs->root);
+ pwd = *path_get(&current->fs->pwd);
+ root = *path_get(&current->fs->root);
read_unlock(&current->fs->lock);

error = -ENOENT;
/* Has the current directory has been unlinked? */
spin_lock(&dcache_lock);
- if (pwd->d_parent == pwd || !d_unhashed(pwd)) {
+ if (pwd.dentry->d_parent == pwd.dentry || !d_unhashed(pwd.dentry)) {
unsigned long len;
char * cwd;

- cwd = __d_path(pwd, pwdmnt, root, rootmnt, page, PAGE_SIZE);
+ cwd = __d_path(pwd.dentry, pwd.mnt, root.dentry, root.mnt,
+ page, PAGE_SIZE);
spin_unlock(&dcache_lock);

error = PTR_ERR(cwd);
@@ -1960,10 +1955,8 @@ asmlinkage long sys_getcwd(char __user *
spin_unlock(&dcache_lock);

out:
- dput(pwd);
- mntput(pwdmnt);
- dput(root);
- mntput(rootmnt);
+ path_put(&pwd);
+ path_put(&root);
free_page((unsigned long) page);
return error;
}
Index: b/fs/namei.c
===================================================================
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -535,16 +535,14 @@ walk_init_root(const char *name, struct
struct fs_struct *fs = current->fs;

read_lock(&fs->lock);
- if (fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
- nd->path.mnt = mntget(fs->altrootmnt);
- nd->path.dentry = dget(fs->altroot);
+ if (fs->altroot.dentry && !(nd->flags & LOOKUP_NOALT)) {
+ nd->path = *path_get(&fs->altroot);
read_unlock(&fs->lock);
if (__emul_lookup_dentry(name,nd))
return 0;
read_lock(&fs->lock);
}
- nd->path.mnt = mntget(fs->rootmnt);
- nd->path.dentry = dget(fs->root);
+ nd->path = *path_get(&fs->root);
read_unlock(&fs->lock);
return 1;
}
@@ -741,8 +739,8 @@ static __always_inline void follow_dotdo
struct dentry *old = nd->path.dentry;

read_lock(&fs->lock);
- if (nd->path.dentry == fs->root &&
- nd->path.mnt == fs->rootmnt) {
+ if (nd->path.dentry == fs->root.dentry &&
+ nd->path.mnt == fs->root.mnt) {
read_unlock(&fs->lock);
break;
}
@@ -1064,8 +1062,7 @@ static int __emul_lookup_dentry(const ch
*/
nd->last_type = LAST_ROOT;
read_lock(&fs->lock);
- nd->path.mnt = mntget(fs->rootmnt);
- nd->path.dentry = dget(fs->root);
+ nd->path = *path_get(&fs->root);
read_unlock(&fs->lock);
if (path_walk(name, nd) == 0) {
if (nd->path.dentry->d_inode) {
@@ -1085,29 +1082,22 @@ void set_fs_altroot(void)
{
char *emul = __emul_prefix();
struct nameidata nd;
- struct vfsmount *mnt = NULL, *oldmnt;
- struct dentry *dentry = NULL, *olddentry;
+ struct path path = {}, old_path;
int err;
struct fs_struct *fs = current->fs;

if (!emul)
goto set_it;
err = path_lookup(emul, LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_NOALT, &nd);
- if (!err) {
- mnt = nd.path.mnt;
- dentry = nd.path.dentry;
- }
+ if (!err)
+ path = nd.path;
set_it:
write_lock(&fs->lock);
- oldmnt = fs->altrootmnt;
- olddentry = fs->altroot;
- fs->altrootmnt = mnt;
- fs->altroot = dentry;
+ old_path = fs->altroot;
+ fs->altroot = path;
write_unlock(&fs->lock);
- if (olddentry) {
- dput(olddentry);
- mntput(oldmnt);
- }
+ if (old_path.dentry)
+ path_put(&old_path);
}

/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
@@ -1125,21 +1115,18 @@ static int fastcall do_path_lookup(int d

if (*name=='/') {
read_lock(&fs->lock);
- if (fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
- nd->path.mnt = mntget(fs->altrootmnt);
- nd->path.dentry = dget(fs->altroot);
+ if (fs->altroot.dentry && !(nd->flags & LOOKUP_NOALT)) {
+ nd->path = *path_get(&fs->altroot);
read_unlock(&fs->lock);
if (__emul_lookup_dentry(name,nd))
goto out; /* found in altroot */
read_lock(&fs->lock);
}
- nd->path.mnt = mntget(fs->rootmnt);
- nd->path.dentry = dget(fs->root);
+ nd->path = *path_get(&fs->root);
read_unlock(&fs->lock);
} else if (dfd == AT_FDCWD) {
read_lock(&fs->lock);
- nd->path.mnt = mntget(fs->pwdmnt);
- nd->path.dentry = dget(fs->pwd);
+ nd->path = *path_get(&fs->pwd);
read_unlock(&fs->lock);
} else {
struct dentry *dentry;
Index: b/fs/namespace.c
===================================================================
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -551,7 +551,7 @@ static int do_umount(struct vfsmount *mn
* (2) the usage count == 1 [parent vfsmount] + 1 [sys_umount]
*/
if (flags & MNT_EXPIRE) {
- if (mnt == current->fs->rootmnt ||
+ if (mnt == current->fs->root.mnt ||
flags & (MNT_FORCE | MNT_DETACH))
return -EINVAL;

@@ -586,7 +586,7 @@ static int do_umount(struct vfsmount *mn
* /reboot - static binary that would close all descriptors and
* call reboot(9). Then init(8) could umount root and exec /reboot.
*/
- if (mnt == current->fs->rootmnt && !(flags & MNT_DETACH)) {
+ if (mnt == current->fs->root.mnt && !(flags & MNT_DETACH)) {
/*
* Special case for "unmounting" root ...
* we just try to remount it readonly.
@@ -1489,17 +1489,17 @@ static struct mnt_namespace *dup_mnt_ns(
while (p) {
q->mnt_ns = new_ns;
if (fs) {
- if (p == fs->rootmnt) {
+ if (p == fs->root.mnt) {
rootmnt = p;
- fs->rootmnt = mntget(q);
+ fs->root.mnt = mntget(q);
}
- if (p == fs->pwdmnt) {
+ if (p == fs->pwd.mnt) {
pwdmnt = p;
- fs->pwdmnt = mntget(q);
+ fs->pwd.mnt = mntget(q);
}
- if (p == fs->altrootmnt) {
+ if (p == fs->altroot.mnt) {
altrootmnt = p;
- fs->altrootmnt = mntget(q);
+ fs->altroot.mnt = mntget(q);
}
}
p = next_mnt(p, mnt_ns->root);
@@ -1583,18 +1583,15 @@ out1:
void set_fs_root(struct fs_struct *fs, struct vfsmount *mnt,
struct dentry *dentry)
{
- struct dentry *old_root;
- struct vfsmount *old_rootmnt;
+ struct path old_root;
+
write_lock(&fs->lock);
old_root = fs->root;
- old_rootmnt = fs->rootmnt;
- fs->rootmnt = mntget(mnt);
- fs->root = dget(dentry);
+ fs->root.mnt = mntget(mnt);
+ fs->root.dentry = dget(dentry);
write_unlock(&fs->lock);
- if (old_root) {
- dput(old_root);
- mntput(old_rootmnt);
- }
+ if (old_root.dentry)
+ path_put(&old_root);
}

/*
@@ -1604,20 +1601,16 @@ void set_fs_root(struct fs_struct *fs, s
void set_fs_pwd(struct fs_struct *fs, struct vfsmount *mnt,
struct dentry *dentry)
{
- struct dentry *old_pwd;
- struct vfsmount *old_pwdmnt;
+ struct path old_pwd;

write_lock(&fs->lock);
old_pwd = fs->pwd;
- old_pwdmnt = fs->pwdmnt;
- fs->pwdmnt = mntget(mnt);
- fs->pwd = dget(dentry);
+ fs->pwd.mnt = mntget(mnt);
+ fs->pwd.dentry = dget(dentry);
write_unlock(&fs->lock);

- if (old_pwd) {
- dput(old_pwd);
- mntput(old_pwdmnt);
- }
+ if (old_pwd.dentry)
+ path_put(&old_pwd);
}

static void chroot_fs_refs(struct nameidata *old_nd, struct nameidata *new_nd)
@@ -1632,12 +1625,12 @@ static void chroot_fs_refs(struct nameid
if (fs) {
atomic_inc(&fs->count);
task_unlock(p);
- if (fs->root == old_nd->path.dentry
- && fs->rootmnt == old_nd->path.mnt)
+ if (fs->root.dentry == old_nd->path.dentry
+ && fs->root.mnt == old_nd->path.mnt)
set_fs_root(fs, new_nd->path.mnt,
new_nd->path.dentry);
- if (fs->pwd == old_nd->path.dentry
- && fs->pwdmnt == old_nd->path.mnt)
+ if (fs->pwd.dentry == old_nd->path.dentry
+ && fs->pwd.mnt == old_nd->path.mnt)
set_fs_pwd(fs, new_nd->path.mnt,
new_nd->path.dentry);
put_fs_struct(fs);
@@ -1703,8 +1696,7 @@ asmlinkage long sys_pivot_root(const cha
}

read_lock(&current->fs->lock);
- user_nd.path.mnt = mntget(current->fs->rootmnt);
- user_nd.path.dentry = dget(current->fs->root);
+ user_nd.path = *path_get(&current->fs->root);
read_unlock(&current->fs->lock);
down_write(&namespace_sem);
mutex_lock(&old_nd.path.dentry->d_inode->i_mutex);
Index: b/fs/proc/base.c
===================================================================
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -162,8 +162,8 @@ static int proc_cwd_link(struct inode *i
}
if (fs) {
read_lock(&fs->lock);
- *mnt = mntget(fs->pwdmnt);
- *dentry = dget(fs->pwd);
+ *mnt = mntget(fs->pwd.mnt);
+ *dentry = dget(fs->pwd.dentry);
read_unlock(&fs->lock);
result = 0;
put_fs_struct(fs);
@@ -183,8 +183,8 @@ static int proc_root_link(struct inode *
}
if (fs) {
read_lock(&fs->lock);
- *mnt = mntget(fs->rootmnt);
- *dentry = dget(fs->root);
+ *mnt = mntget(fs->root.mnt);
+ *dentry = dget(fs->root.dentry);
read_unlock(&fs->lock);
result = 0;
put_fs_struct(fs);
Index: b/include/linux/fs_struct.h
===================================================================
--- a/include/linux/fs_struct.h
+++ b/include/linux/fs_struct.h
@@ -1,15 +1,13 @@
#ifndef _LINUX_FS_STRUCT_H
#define _LINUX_FS_STRUCT_H

-struct dentry;
-struct vfsmount;
+#include <linux/path.h>

struct fs_struct {
atomic_t count;
rwlock_t lock;
int umask;
- struct dentry * root, * pwd, * altroot;
- struct vfsmount * rootmnt, * pwdmnt, * altrootmnt;
+ struct path root, pwd, altroot;
};

#define INIT_FS { \
Index: b/init/do_mounts.c
===================================================================
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -286,10 +286,10 @@ static int __init do_mount_root(char *na
return err;

sys_chdir("/root");
- ROOT_DEV = current->fs->pwdmnt->mnt_sb->s_dev;
+ ROOT_DEV = current->fs->pwd.mnt->mnt_sb->s_dev;
printk("VFS: Mounted root (%s filesystem)%s.\n",
- current->fs->pwdmnt->mnt_sb->s_type->name,
- current->fs->pwdmnt->mnt_sb->s_flags & MS_RDONLY ?
+ current->fs->pwd.mnt->mnt_sb->s_type->name,
+ current->fs->pwd.mnt->mnt_sb->s_flags & MS_RDONLY ?
" readonly" : "");
return 0;
}
Index: b/kernel/auditsc.c
===================================================================
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1313,8 +1313,8 @@ void __audit_getname(const char *name)
++context->name_count;
if (!context->pwd) {
read_lock(&current->fs->lock);
- context->pwd = dget(current->fs->pwd);
- context->pwdmnt = mntget(current->fs->pwdmnt);
+ context->pwd = dget(current->fs->pwd.dentry);
+ context->pwdmnt = mntget(current->fs->pwd.mnt);
read_unlock(&current->fs->lock);
}

Index: b/kernel/exit.c
===================================================================
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -514,14 +514,10 @@ static inline void __put_fs_struct(struc
{
/* No need to hold fs->lock if we are killing it */
if (atomic_dec_and_test(&fs->count)) {
- dput(fs->root);
- mntput(fs->rootmnt);
- dput(fs->pwd);
- mntput(fs->pwdmnt);
- if (fs->altroot) {
- dput(fs->altroot);
- mntput(fs->altrootmnt);
- }
+ path_put(&fs->root);
+ path_put(&fs->pwd);
+ if (fs->altroot.dentry)
+ path_put(&fs->altroot);
kmem_cache_free(fs_cachep, fs);
}
}
Index: b/kernel/fork.c
===================================================================
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -582,16 +582,13 @@ static inline struct fs_struct *__copy_f
rwlock_init(&fs->lock);
fs->umask = old->umask;
read_lock(&old->lock);
- fs->rootmnt = mntget(old->rootmnt);
- fs->root = dget(old->root);
- fs->pwdmnt = mntget(old->pwdmnt);
- fs->pwd = dget(old->pwd);
- if (old->altroot) {
- fs->altrootmnt = mntget(old->altrootmnt);
- fs->altroot = dget(old->altroot);
- } else {
- fs->altrootmnt = NULL;
- fs->altroot = NULL;
+ fs->root = *path_get(&old->root);
+ fs->pwd = *path_get(&old->pwd);
+ if (old->altroot.dentry)
+ fs->altroot = *path_get(&old->altroot);
+ else {
+ fs->altroot.mnt = NULL;
+ fs->altroot.dentry = NULL;
}
read_unlock(&old->lock);
}

--

-
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