The patch titled
fs/namei.c: replace multiple current->fs by shortcut variable
has been added to the -mm tree. Its filename is
fs-nameic-replace-multiple-current-fs-by-shortcut-variable.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: fs/namei.c: replace multiple current->fs by shortcut variable
From: Andreas Mohr <andi@xxxxxxxxxxxxxxxxxxxxxxx>
Replace current->fs by fs helper variable to reduce some indirection
overhead and (at least at the moment, before the current_thread_info() %gs
PDA improvement is available) get rid of more costly current references.
Reduces fs/namei.o from 37786 to 37082 Bytes (704 Bytes saved).
Signed-off-by: Andreas Mohr <andi@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/namei.c | 79 +++++++++++++++++++++++++++------------------------
1 files changed, 42 insertions(+), 37 deletions(-)
diff -puN fs/namei.c~fs-nameic-replace-multiple-current-fs-by-shortcut-variable fs/namei.c
--- a/fs/namei.c~fs-nameic-replace-multiple-current-fs-by-shortcut-variable
+++ a/fs/namei.c
@@ -518,18 +518,19 @@ static int __emul_lookup_dentry(const ch
static __always_inline int
walk_init_root(const char *name, struct nameidata *nd)
{
- read_lock(¤t->fs->lock);
- if (current->fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
- nd->mnt = mntget(current->fs->altrootmnt);
- nd->dentry = dget(current->fs->altroot);
- read_unlock(¤t->fs->lock);
+ struct fs_struct *fs = current->fs;
+ read_lock(&fs->lock);
+ if (fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
+ nd->mnt = mntget(fs->altrootmnt);
+ nd->dentry = dget(fs->altroot);
+ read_unlock(&fs->lock);
if (__emul_lookup_dentry(name,nd))
return 0;
- read_lock(¤t->fs->lock);
+ read_lock(&fs->lock);
}
- nd->mnt = mntget(current->fs->rootmnt);
- nd->dentry = dget(current->fs->root);
- read_unlock(¤t->fs->lock);
+ nd->mnt = mntget(fs->rootmnt);
+ nd->dentry = dget(fs->root);
+ read_unlock(&fs->lock);
return 1;
}
@@ -724,17 +725,18 @@ int follow_down(struct vfsmount **mnt, s
static __always_inline void follow_dotdot(struct nameidata *nd)
{
+ struct fs_struct *fs = current->fs;
while(1) {
struct vfsmount *parent;
struct dentry *old = nd->dentry;
- read_lock(¤t->fs->lock);
- if (nd->dentry == current->fs->root &&
- nd->mnt == current->fs->rootmnt) {
- read_unlock(¤t->fs->lock);
+ read_lock(&fs->lock);
+ if (nd->dentry == fs->root &&
+ nd->mnt == fs->rootmnt) {
+ read_unlock(&fs->lock);
break;
}
- read_unlock(¤t->fs->lock);
+ read_unlock(&fs->lock);
spin_lock(&dcache_lock);
if (nd->dentry != nd->mnt->mnt_root) {
nd->dentry = dget(nd->dentry->d_parent);
@@ -1042,15 +1044,16 @@ static int __emul_lookup_dentry(const ch
struct vfsmount *old_mnt = nd->mnt;
struct qstr last = nd->last;
int last_type = nd->last_type;
+ struct fs_struct *fs = current->fs;
/*
* NAME was not found in alternate root or it's a directory. Try to find
* it in the normal root:
*/
nd->last_type = LAST_ROOT;
- read_lock(¤t->fs->lock);
- nd->mnt = mntget(current->fs->rootmnt);
- nd->dentry = dget(current->fs->root);
- read_unlock(¤t->fs->lock);
+ read_lock(&fs->lock);
+ nd->mnt = mntget(fs->rootmnt);
+ nd->dentry = dget(fs->root);
+ read_unlock(&fs->lock);
if (path_walk(name, nd) == 0) {
if (nd->dentry->d_inode) {
dput(old_dentry);
@@ -1074,6 +1077,7 @@ void set_fs_altroot(void)
struct vfsmount *mnt = NULL, *oldmnt;
struct dentry *dentry = NULL, *olddentry;
int err;
+ struct fs_struct *fs = current->fs;
if (!emul)
goto set_it;
@@ -1083,12 +1087,12 @@ void set_fs_altroot(void)
dentry = nd.dentry;
}
set_it:
- write_lock(¤t->fs->lock);
- oldmnt = current->fs->altrootmnt;
- olddentry = current->fs->altroot;
- current->fs->altrootmnt = mnt;
- current->fs->altroot = dentry;
- write_unlock(¤t->fs->lock);
+ write_lock(&fs->lock);
+ oldmnt = fs->altrootmnt;
+ olddentry = fs->altroot;
+ fs->altrootmnt = mnt;
+ fs->altroot = dentry;
+ write_unlock(&fs->lock);
if (olddentry) {
dput(olddentry);
mntput(oldmnt);
@@ -1102,29 +1106,30 @@ static int fastcall do_path_lookup(int d
int retval = 0;
int fput_needed;
struct file *file;
+ struct fs_struct *fs = current->fs;
nd->last_type = LAST_ROOT; /* if there are only slashes... */
nd->flags = flags;
nd->depth = 0;
if (*name=='/') {
- read_lock(¤t->fs->lock);
- if (current->fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
- nd->mnt = mntget(current->fs->altrootmnt);
- nd->dentry = dget(current->fs->altroot);
- read_unlock(¤t->fs->lock);
+ read_lock(&fs->lock);
+ if (fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
+ nd->mnt = mntget(fs->altrootmnt);
+ nd->dentry = dget(fs->altroot);
+ read_unlock(&fs->lock);
if (__emul_lookup_dentry(name,nd))
goto out; /* found in altroot */
- read_lock(¤t->fs->lock);
+ read_lock(&fs->lock);
}
- nd->mnt = mntget(current->fs->rootmnt);
- nd->dentry = dget(current->fs->root);
- read_unlock(¤t->fs->lock);
+ nd->mnt = mntget(fs->rootmnt);
+ nd->dentry = dget(fs->root);
+ read_unlock(&fs->lock);
} else if (dfd == AT_FDCWD) {
- read_lock(¤t->fs->lock);
- nd->mnt = mntget(current->fs->pwdmnt);
- nd->dentry = dget(current->fs->pwd);
- read_unlock(¤t->fs->lock);
+ read_lock(&fs->lock);
+ nd->mnt = mntget(fs->pwdmnt);
+ nd->dentry = dget(fs->pwd);
+ read_unlock(&fs->lock);
} else {
struct dentry *dentry;
_
Patches currently in -mm which might be from andi@xxxxxxxxxxxxxxxxxxxxxxx are
acx1xx-wireless-driver.patch
lib-rwsemc-un-inline-rwsem_down_failed_common.patch
fs-nameic-replace-multiple-current-fs-by-shortcut-variable.patch
fs-inodec-tweaks.patch
-
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