1 files changed, 117 insertions, 92 deletions

diff --git a/fs/namei.c b/fs/namei.c
index 808e4ea2bb94..28d49b301d55 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(&current->fs->lock);
-        if (current->fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
-                nd->mnt = mntget(current->fs->altrootmnt);
-                nd->dentry = dget(current->fs->altroot);
-                read_unlock(&current->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(&current->fs->lock);
+                read_lock(&fs->lock);
         }
-        nd->mnt = mntget(current->fs->rootmnt);
-        nd->dentry = dget(current->fs->root);
-        read_unlock(&current->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(&current->fs->lock);
-                if (nd->dentry == current->fs->root &&
-                    nd->mnt == current->fs->rootmnt) {
-                        read_unlock(&current->fs->lock);
+                read_lock(&fs->lock);
+                if (nd->dentry == fs->root &&
+                    nd->mnt == fs->rootmnt) {
+                        read_unlock(&fs->lock);
                         break;
                 }
-                read_unlock(&current->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(&current->fs->lock);
-                nd->mnt = mntget(current->fs->rootmnt);
-                nd->dentry = dget(current->fs->root);
-                read_unlock(&current->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(&current->fs->lock);
-        oldmnt = current->fs->altrootmnt;
-        olddentry = current->fs->altroot;
-        current->fs->altrootmnt = mnt;
-        current->fs->altroot = dentry;
-        write_unlock(&current->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(&current->fs->lock);
-                if (current->fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
-                        nd->mnt = mntget(current->fs->altrootmnt);
-                        nd->dentry = dget(current->fs->altroot);
-                        read_unlock(&current->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(&current->fs->lock);
+                        read_lock(&fs->lock);
                 }
-                nd->mnt = mntget(current->fs->rootmnt);
-                nd->dentry = dget(current->fs->root);
-                read_unlock(&current->fs->lock);
+                nd->mnt = mntget(fs->rootmnt);
+                nd->dentry = dget(fs->root);
+                read_unlock(&fs->lock);
         } else if (dfd == AT_FDCWD) {
-                read_lock(&current->fs->lock);
-                nd->mnt = mntget(current->fs->pwdmnt);
-                nd->dentry = dget(current->fs->pwd);
-                read_unlock(&current->fs->lock);
+                read_lock(&fs->lock);
+                nd->mnt = mntget(fs->pwdmnt);
+                nd->dentry = dget(fs->pwd);
+                read_unlock(&fs->lock);
         } else {
                 struct dentry *dentry;
 
@@ -1587,6 +1595,24 @@ int may_open(struct nameidata *nd, int acc_mode, int flag)
         return 0;
 }
 
+static int open_namei_create(struct nameidata *nd, struct path *path,
+                                int flag, int mode)
+{
+        int error;
+        struct dentry *dir = nd->dentry;
+
+        if (!IS_POSIXACL(dir->d_inode))
+                mode &= ~current->fs->umask;
+        error = vfs_create(dir->d_inode, path->dentry, mode, nd);
+        mutex_unlock(&dir->d_inode->i_mutex);
+        dput(nd->dentry);
+        nd->dentry = path->dentry;
+        if (error)
+                return error;
+        /* Don't check for write permission, don't truncate */
+        return may_open(nd, 0, flag & ~O_TRUNC);
+}
+
 /*
  *      open_namei()
  *
@@ -1668,18 +1694,10 @@ do_last:
 
         /* Negative dentry, just create the file */
         if (!path.dentry->d_inode) {
-                if (!IS_POSIXACL(dir->d_inode))
-                        mode &= ~current->fs->umask;
-                error = vfs_create(dir->d_inode, path.dentry, mode, nd);
-                mutex_unlock(&dir->d_inode->i_mutex);
-                dput(nd->dentry);
-                nd->dentry = path.dentry;
+                error = open_namei_create(nd, &path, flag, mode);
                 if (error)
                         goto exit;
-                /* Don't check for write permission, don't truncate */
-                acc_mode = 0;
-                flag &= ~O_TRUNC;
-                goto ok;
+                return 0;
         }
 
         /*
@@ -1926,30 +1944,32 @@ asmlinkage long sys_mkdirat(int dfd, const char __user *pathname, int mode)
 {
         int error = 0;
         char * tmp;
+        struct dentry *dentry;
+        struct nameidata nd;
 
         tmp = getname(pathname);
         error = PTR_ERR(tmp);
-        if (!IS_ERR(tmp)) {
-                struct dentry *dentry;
-                struct nameidata nd;
+        if (IS_ERR(tmp))
+                goto out_err;
 
-                error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd);
-                if (error)
-                        goto out;
-                dentry = lookup_create(&nd, 1);
-                error = PTR_ERR(dentry);
-                if (!IS_ERR(dentry)) {
-                        if (!IS_POSIXACL(nd.dentry->d_inode))
-                                mode &= ~current->fs->umask;
-                        error = vfs_mkdir(nd.dentry->d_inode, dentry, mode);
-                        dput(dentry);
-                }
-                mutex_unlock(&nd.dentry->d_inode->i_mutex);
-                path_release(&nd);
-out:
-                putname(tmp);
-        }
+        error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd);
+        if (error)
+                goto out;
+        dentry = lookup_create(&nd, 1);
+        error = PTR_ERR(dentry);
+        if (IS_ERR(dentry))
+                goto out_unlock;
 
+        if (!IS_POSIXACL(nd.dentry->d_inode))
+                mode &= ~current->fs->umask;
+        error = vfs_mkdir(nd.dentry->d_inode, dentry, mode);
+        dput(dentry);
+out_unlock:
+        mutex_unlock(&nd.dentry->d_inode->i_mutex);
+        path_release(&nd);
+out:
+        putname(tmp);
+out_err:
         return error;
 }
 
@@ -2048,10 +2068,11 @@ static long do_rmdir(int dfd, const char __user *pathname)
         mutex_lock_nested(&nd.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
         dentry = lookup_hash(&nd);
         error = PTR_ERR(dentry);
-        if (!IS_ERR(dentry)) {
-                error = vfs_rmdir(nd.dentry->d_inode, dentry);
-                dput(dentry);
-        }
+        if (IS_ERR(dentry))
+                goto exit2;
+        error = vfs_rmdir(nd.dentry->d_inode, dentry);
+        dput(dentry);
+exit2:
         mutex_unlock(&nd.dentry->d_inode->i_mutex);
 exit1:
         path_release(&nd);
@@ -2191,30 +2212,33 @@ asmlinkage long sys_symlinkat(const char __user *oldname,
         int error = 0;
         char * from;
         char * to;
+        struct dentry *dentry;
+        struct nameidata nd;
 
         from = getname(oldname);
         if(IS_ERR(from))
                 return PTR_ERR(from);
         to = getname(newname);
         error = PTR_ERR(to);
-        if (!IS_ERR(to)) {
-                struct dentry *dentry;
-                struct nameidata nd;
+        if (IS_ERR(to))
+                goto out_putname;
 
-                error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd);
-                if (error)
-                        goto out;
-                dentry = lookup_create(&nd, 0);
-                error = PTR_ERR(dentry);
-                if (!IS_ERR(dentry)) {
-                        error = vfs_symlink(nd.dentry->d_inode, dentry, from, S_IALLUGO);
-                        dput(dentry);
-                }
-                mutex_unlock(&nd.dentry->d_inode->i_mutex);
-                path_release(&nd);
+        error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd);
+        if (error)
+                goto out;
+        dentry = lookup_create(&nd, 0);
+        error = PTR_ERR(dentry);
+        if (IS_ERR(dentry))
+                goto out_unlock;
+
+        error = vfs_symlink(nd.dentry->d_inode, dentry, from, S_IALLUGO);
+        dput(dentry);
+out_unlock:
+        mutex_unlock(&nd.dentry->d_inode->i_mutex);
+        path_release(&nd);
 out:
-                putname(to);
-        }
+        putname(to);
+out_putname:
         putname(from);
         return error;
 }
@@ -2300,10 +2324,11 @@ asmlinkage long sys_linkat(int olddfd, const char __user *oldname,
                 goto out_release;
         new_dentry = lookup_create(&nd, 0);
         error = PTR_ERR(new_dentry);
-        if (!IS_ERR(new_dentry)) {
-                error = vfs_link(old_nd.dentry, nd.dentry->d_inode, new_dentry);
-                dput(new_dentry);
-        }
+        if (IS_ERR(new_dentry))
+                goto out_unlock;
+        error = vfs_link(old_nd.dentry, nd.dentry->d_inode, new_dentry);
+        dput(new_dentry);
+out_unlock:
         mutex_unlock(&nd.dentry->d_inode->i_mutex);
 out_release:
         path_release(&nd);