From e518ddb7ba44a3d852c0e41961365844c76eb2bf Mon Sep 17 00:00:00 2001 From: Andreas Mohr Date: Fri, 29 Sep 2006 02:01:22 -0700 Subject: [PATCH] [PATCH] fs/namei.c: replace multiple current->fs by shortcut variable 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). [akpm@osdl.org: cleanup] Signed-off-by: Andreas Mohr Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/namei.c | 86 +++++++++++++++++++++++++++++------------------------- 1 file changed, 47 insertions(+), 39 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 808e4ea2bb94..2892e68d3a86 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -518,18 +518,20 @@ static int __emul_lookup_dentry(const char *, struct nameidata *); 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 +726,19 @@ int follow_down(struct vfsmount **mnt, struct dentry **dentry) 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 +1046,17 @@ static int __emul_lookup_dentry(const char *name, struct nameidata *nd) 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: + * 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 +1080,7 @@ 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 +1090,12 @@ 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 +1109,30 @@ static int fastcall do_path_lookup(int dfd, const char *name, 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;