From 4ac9137858e08a19f29feac4e1f4df7c268b0ba5 Mon Sep 17 00:00:00 2001 From: Jan Blunck Date: Thu, 14 Feb 2008 19:34:32 -0800 Subject: Embed a struct path into struct nameidata instead of nd->{dentry,mnt} This is the central patch of a cleanup series. In most cases there is no good reason why someone would want to use a dentry for itself. This series reflects that fact and embeds a struct path into nameidata. Together with the other patches of this series - it enforced the correct order of getting/releasing the reference count on pairs - it prepares the VFS for stacking support since it is essential to have a struct path in every place where the stack can be traversed - it reduces the overall code size: without patch series: text data bss dec hex filename 5321639 858418 715768 6895825 6938d1 vmlinux with patch series: text data bss dec hex filename 5320026 858418 715768 6894212 693284 vmlinux This patch: Switch from nd->{dentry,mnt} to nd->path.{dentry,mnt} everywhere. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix cifs] [akpm@linux-foundation.org: fix smack] Signed-off-by: Jan Blunck Signed-off-by: Andreas Gruenbacher Acked-by: Christoph Hellwig Cc: Al Viro Cc: Casey Schaufler Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/namei.c | 220 +++++++++++++++++++++++++++++++------------------------------ 1 file changed, 112 insertions(+), 108 deletions(-) (limited to 'fs/namei.c') diff --git a/fs/namei.c b/fs/namei.c index 3ed4d7576d6..c9b05a71c39 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -231,7 +231,7 @@ int permission(struct inode *inode, int mask, struct nameidata *nd) struct vfsmount *mnt = NULL; if (nd) - mnt = nd->mnt; + mnt = nd->path.mnt; if (mask & MAY_WRITE) { umode_t mode = inode->i_mode; @@ -296,7 +296,7 @@ int permission(struct inode *inode, int mask, struct nameidata *nd) */ int vfs_permission(struct nameidata *nd, int mask) { - return permission(nd->dentry->d_inode, mask, nd); + return permission(nd->path.dentry->d_inode, mask, nd); } /** @@ -364,8 +364,8 @@ int deny_write_access(struct file * file) void path_release(struct nameidata *nd) { - dput(nd->dentry); - mntput(nd->mnt); + dput(nd->path.dentry); + mntput(nd->path.mnt); } /** @@ -530,15 +530,15 @@ walk_init_root(const char *name, struct nameidata *nd) read_lock(&fs->lock); if (fs->altroot && !(nd->flags & LOOKUP_NOALT)) { - nd->mnt = mntget(fs->altrootmnt); - nd->dentry = dget(fs->altroot); + nd->path.mnt = mntget(fs->altrootmnt); + nd->path.dentry = dget(fs->altroot); read_unlock(&fs->lock); if (__emul_lookup_dentry(name,nd)) return 0; read_lock(&fs->lock); } - nd->mnt = mntget(fs->rootmnt); - nd->dentry = dget(fs->root); + nd->path.mnt = mntget(fs->rootmnt); + nd->path.dentry = dget(fs->root); read_unlock(&fs->lock); return 1; } @@ -581,17 +581,17 @@ fail: static inline void dput_path(struct path *path, struct nameidata *nd) { dput(path->dentry); - if (path->mnt != nd->mnt) + if (path->mnt != nd->path.mnt) mntput(path->mnt); } static inline void path_to_nameidata(struct path *path, struct nameidata *nd) { - dput(nd->dentry); - if (nd->mnt != path->mnt) - mntput(nd->mnt); - nd->mnt = path->mnt; - nd->dentry = path->dentry; + dput(nd->path.dentry); + if (nd->path.mnt != path->mnt) + mntput(nd->path.mnt); + nd->path.mnt = path->mnt; + nd->path.dentry = path->dentry; } static __always_inline int __do_follow_link(struct path *path, struct nameidata *nd) @@ -603,7 +603,7 @@ static __always_inline int __do_follow_link(struct path *path, struct nameidata touch_atime(path->mnt, dentry); nd_set_link(nd, NULL); - if (path->mnt != nd->mnt) { + if (path->mnt != nd->path.mnt) { path_to_nameidata(path, nd); dget(dentry); } @@ -733,37 +733,37 @@ static __always_inline void follow_dotdot(struct nameidata *nd) while(1) { struct vfsmount *parent; - struct dentry *old = nd->dentry; + struct dentry *old = nd->path.dentry; read_lock(&fs->lock); - if (nd->dentry == fs->root && - nd->mnt == fs->rootmnt) { + if (nd->path.dentry == fs->root && + nd->path.mnt == fs->rootmnt) { read_unlock(&fs->lock); break; } read_unlock(&fs->lock); spin_lock(&dcache_lock); - if (nd->dentry != nd->mnt->mnt_root) { - nd->dentry = dget(nd->dentry->d_parent); + if (nd->path.dentry != nd->path.mnt->mnt_root) { + nd->path.dentry = dget(nd->path.dentry->d_parent); spin_unlock(&dcache_lock); dput(old); break; } spin_unlock(&dcache_lock); spin_lock(&vfsmount_lock); - parent = nd->mnt->mnt_parent; - if (parent == nd->mnt) { + parent = nd->path.mnt->mnt_parent; + if (parent == nd->path.mnt) { spin_unlock(&vfsmount_lock); break; } mntget(parent); - nd->dentry = dget(nd->mnt->mnt_mountpoint); + nd->path.dentry = dget(nd->path.mnt->mnt_mountpoint); spin_unlock(&vfsmount_lock); dput(old); - mntput(nd->mnt); - nd->mnt = parent; + mntput(nd->path.mnt); + nd->path.mnt = parent; } - follow_mount(&nd->mnt, &nd->dentry); + follow_mount(&nd->path.mnt, &nd->path.dentry); } /* @@ -774,8 +774,8 @@ static __always_inline void follow_dotdot(struct nameidata *nd) static int do_lookup(struct nameidata *nd, struct qstr *name, struct path *path) { - struct vfsmount *mnt = nd->mnt; - struct dentry *dentry = __d_lookup(nd->dentry, name); + struct vfsmount *mnt = nd->path.mnt; + struct dentry *dentry = __d_lookup(nd->path.dentry, name); if (!dentry) goto need_lookup; @@ -788,7 +788,7 @@ done: return 0; need_lookup: - dentry = real_lookup(nd->dentry, name, nd); + dentry = real_lookup(nd->path.dentry, name, nd); if (IS_ERR(dentry)) goto fail; goto done; @@ -825,7 +825,7 @@ static int __link_path_walk(const char *name, struct nameidata *nd) if (!*name) goto return_reval; - inode = nd->dentry->d_inode; + inode = nd->path.dentry->d_inode; if (nd->depth) lookup_flags = LOOKUP_FOLLOW | (nd->flags & LOOKUP_CONTINUE); @@ -873,7 +873,7 @@ static int __link_path_walk(const char *name, struct nameidata *nd) if (this.name[1] != '.') break; follow_dotdot(nd); - inode = nd->dentry->d_inode; + inode = nd->path.dentry->d_inode; /* fallthrough */ case 1: continue; @@ -882,8 +882,9 @@ static int __link_path_walk(const char *name, struct nameidata *nd) * See if the low-level filesystem might want * to use its own hash.. */ - if (nd->dentry->d_op && nd->dentry->d_op->d_hash) { - err = nd->dentry->d_op->d_hash(nd->dentry, &this); + if (nd->path.dentry->d_op && nd->path.dentry->d_op->d_hash) { + err = nd->path.dentry->d_op->d_hash(nd->path.dentry, + &this); if (err < 0) break; } @@ -905,7 +906,7 @@ static int __link_path_walk(const char *name, struct nameidata *nd) if (err) goto return_err; err = -ENOENT; - inode = nd->dentry->d_inode; + inode = nd->path.dentry->d_inode; if (!inode) break; err = -ENOTDIR; @@ -933,13 +934,14 @@ last_component: if (this.name[1] != '.') break; follow_dotdot(nd); - inode = nd->dentry->d_inode; + inode = nd->path.dentry->d_inode; /* fallthrough */ case 1: goto return_reval; } - if (nd->dentry->d_op && nd->dentry->d_op->d_hash) { - err = nd->dentry->d_op->d_hash(nd->dentry, &this); + if (nd->path.dentry->d_op && nd->path.dentry->d_op->d_hash) { + err = nd->path.dentry->d_op->d_hash(nd->path.dentry, + &this); if (err < 0) break; } @@ -952,7 +954,7 @@ last_component: err = do_follow_link(&next, nd); if (err) goto return_err; - inode = nd->dentry->d_inode; + inode = nd->path.dentry->d_inode; } else path_to_nameidata(&next, nd); err = -ENOENT; @@ -980,11 +982,12 @@ return_reval: * We bypassed the ordinary revalidation routines. * We may need to check the cached dentry for staleness. */ - if (nd->dentry && nd->dentry->d_sb && - (nd->dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT)) { + if (nd->path.dentry && nd->path.dentry->d_sb && + (nd->path.dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT)) { err = -ESTALE; /* Note: we do not d_invalidate() */ - if (!nd->dentry->d_op->d_revalidate(nd->dentry, nd)) + if (!nd->path.dentry->d_op->d_revalidate( + nd->path.dentry, nd)) break; } return_base: @@ -1011,20 +1014,20 @@ static int link_path_walk(const char *name, struct nameidata *nd) int result; /* make sure the stuff we saved doesn't go away */ - dget(save.dentry); - mntget(save.mnt); + dget(save.path.dentry); + mntget(save.path.mnt); result = __link_path_walk(name, nd); if (result == -ESTALE) { *nd = save; - dget(nd->dentry); - mntget(nd->mnt); + dget(nd->path.dentry); + mntget(nd->path.mnt); nd->flags |= LOOKUP_REVAL; result = __link_path_walk(name, nd); } - dput(save.dentry); - mntput(save.mnt); + dput(save.path.dentry); + mntput(save.path.mnt); return result; } @@ -1044,9 +1047,10 @@ static int __emul_lookup_dentry(const char *name, struct nameidata *nd) if (path_walk(name, nd)) return 0; /* something went wrong... */ - if (!nd->dentry->d_inode || S_ISDIR(nd->dentry->d_inode->i_mode)) { - struct dentry *old_dentry = nd->dentry; - struct vfsmount *old_mnt = nd->mnt; + if (!nd->path.dentry->d_inode || + S_ISDIR(nd->path.dentry->d_inode->i_mode)) { + struct dentry *old_dentry = nd->path.dentry; + struct vfsmount *old_mnt = nd->path.mnt; struct qstr last = nd->last; int last_type = nd->last_type; struct fs_struct *fs = current->fs; @@ -1057,19 +1061,19 @@ static int __emul_lookup_dentry(const char *name, struct nameidata *nd) */ nd->last_type = LAST_ROOT; read_lock(&fs->lock); - nd->mnt = mntget(fs->rootmnt); - nd->dentry = dget(fs->root); + nd->path.mnt = mntget(fs->rootmnt); + nd->path.dentry = dget(fs->root); read_unlock(&fs->lock); if (path_walk(name, nd) == 0) { - if (nd->dentry->d_inode) { + if (nd->path.dentry->d_inode) { dput(old_dentry); mntput(old_mnt); return 1; } path_release(nd); } - nd->dentry = old_dentry; - nd->mnt = old_mnt; + nd->path.dentry = old_dentry; + nd->path.mnt = old_mnt; nd->last = last; nd->last_type = last_type; } @@ -1089,8 +1093,8 @@ void set_fs_altroot(void) goto set_it; err = path_lookup(emul, LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_NOALT, &nd); if (!err) { - mnt = nd.mnt; - dentry = nd.dentry; + mnt = nd.path.mnt; + dentry = nd.path.dentry; } set_it: write_lock(&fs->lock); @@ -1121,20 +1125,20 @@ static int do_path_lookup(int dfd, const char *name, if (*name=='/') { read_lock(&fs->lock); if (fs->altroot && !(nd->flags & LOOKUP_NOALT)) { - nd->mnt = mntget(fs->altrootmnt); - nd->dentry = dget(fs->altroot); + nd->path.mnt = mntget(fs->altrootmnt); + nd->path.dentry = dget(fs->altroot); read_unlock(&fs->lock); if (__emul_lookup_dentry(name,nd)) goto out; /* found in altroot */ read_lock(&fs->lock); } - nd->mnt = mntget(fs->rootmnt); - nd->dentry = dget(fs->root); + nd->path.mnt = mntget(fs->rootmnt); + nd->path.dentry = dget(fs->root); read_unlock(&fs->lock); } else if (dfd == AT_FDCWD) { read_lock(&fs->lock); - nd->mnt = mntget(fs->pwdmnt); - nd->dentry = dget(fs->pwd); + nd->path.mnt = mntget(fs->pwdmnt); + nd->path.dentry = dget(fs->pwd); read_unlock(&fs->lock); } else { struct dentry *dentry; @@ -1154,17 +1158,17 @@ static int do_path_lookup(int dfd, const char *name, if (retval) goto fput_fail; - nd->mnt = mntget(file->f_path.mnt); - nd->dentry = dget(dentry); + nd->path.mnt = mntget(file->f_path.mnt); + nd->path.dentry = dget(dentry); fput_light(file, fput_needed); } retval = path_walk(name, nd); out: - if (unlikely(!retval && !audit_dummy_context() && nd->dentry && - nd->dentry->d_inode)) - audit_inode(name, nd->dentry); + if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry && + nd->path.dentry->d_inode)) + audit_inode(name, nd->path.dentry); out_fail: return retval; @@ -1198,13 +1202,13 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt, nd->flags = flags; nd->depth = 0; - nd->mnt = mntget(mnt); - nd->dentry = dget(dentry); + nd->path.mnt = mntget(mnt); + nd->path.dentry = dget(dentry); retval = path_walk(name, nd); - if (unlikely(!retval && !audit_dummy_context() && nd->dentry && - nd->dentry->d_inode)) - audit_inode(name, nd->dentry); + if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry && + nd->path.dentry->d_inode)) + audit_inode(name, nd->path.dentry); return retval; @@ -1323,10 +1327,10 @@ static struct dentry *lookup_hash(struct nameidata *nd) { int err; - err = permission(nd->dentry->d_inode, MAY_EXEC, nd); + err = permission(nd->path.dentry->d_inode, MAY_EXEC, nd); if (err) return ERR_PTR(err); - return __lookup_hash(&nd->last, nd->dentry, nd); + return __lookup_hash(&nd->last, nd->path.dentry, nd); } static int __lookup_one_len(const char *name, struct qstr *this, @@ -1585,7 +1589,7 @@ int vfs_create(struct inode *dir, struct dentry *dentry, int mode, int may_open(struct nameidata *nd, int acc_mode, int flag) { - struct dentry *dentry = nd->dentry; + struct dentry *dentry = nd->path.dentry; struct inode *inode = dentry->d_inode; int error; @@ -1606,7 +1610,7 @@ int may_open(struct nameidata *nd, int acc_mode, int flag) if (S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { flag &= ~O_TRUNC; } else if (S_ISBLK(inode->i_mode) || S_ISCHR(inode->i_mode)) { - if (nd->mnt->mnt_flags & MNT_NODEV) + if (nd->path.mnt->mnt_flags & MNT_NODEV) return -EACCES; flag &= ~O_TRUNC; @@ -1668,14 +1672,14 @@ static int open_namei_create(struct nameidata *nd, struct path *path, int flag, int mode) { int error; - struct dentry *dir = nd->dentry; + struct dentry *dir = nd->path.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; + dput(nd->path.dentry); + nd->path.dentry = path->dentry; if (error) return error; /* Don't check for write permission, don't truncate */ @@ -1742,11 +1746,11 @@ int open_namei(int dfd, const char *pathname, int flag, if (nd->last_type != LAST_NORM || nd->last.name[nd->last.len]) goto exit; - dir = nd->dentry; + dir = nd->path.dentry; nd->flags &= ~LOOKUP_PARENT; mutex_lock(&dir->d_inode->i_mutex); path.dentry = lookup_hash(nd); - path.mnt = nd->mnt; + path.mnt = nd->path.mnt; do_last: error = PTR_ERR(path.dentry); @@ -1851,10 +1855,10 @@ do_link: __putname(nd->last.name); goto exit; } - dir = nd->dentry; + dir = nd->path.dentry; mutex_lock(&dir->d_inode->i_mutex); path.dentry = lookup_hash(nd); - path.mnt = nd->mnt; + path.mnt = nd->path.mnt; __putname(nd->last.name); goto do_last; } @@ -1867,13 +1871,13 @@ do_link: * Simple function to lookup and return a dentry and create it * if it doesn't exist. Is SMP-safe. * - * Returns with nd->dentry->d_inode->i_mutex locked. + * Returns with nd->path.dentry->d_inode->i_mutex locked. */ struct dentry *lookup_create(struct nameidata *nd, int is_dir) { struct dentry *dentry = ERR_PTR(-EEXIST); - mutex_lock_nested(&nd->dentry->d_inode->i_mutex, I_MUTEX_PARENT); + mutex_lock_nested(&nd->path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); /* * Yucky last component or no last component at all? * (foo/., foo/.., /////) @@ -1952,19 +1956,19 @@ asmlinkage long sys_mknodat(int dfd, const char __user *filename, int mode, dentry = lookup_create(&nd, 0); error = PTR_ERR(dentry); - if (!IS_POSIXACL(nd.dentry->d_inode)) + if (!IS_POSIXACL(nd.path.dentry->d_inode)) mode &= ~current->fs->umask; if (!IS_ERR(dentry)) { switch (mode & S_IFMT) { case 0: case S_IFREG: - error = vfs_create(nd.dentry->d_inode,dentry,mode,&nd); + error = vfs_create(nd.path.dentry->d_inode,dentry,mode,&nd); break; case S_IFCHR: case S_IFBLK: - error = vfs_mknod(nd.dentry->d_inode,dentry,mode, + error = vfs_mknod(nd.path.dentry->d_inode,dentry,mode, new_decode_dev(dev)); break; case S_IFIFO: case S_IFSOCK: - error = vfs_mknod(nd.dentry->d_inode,dentry,mode,0); + error = vfs_mknod(nd.path.dentry->d_inode,dentry,mode,0); break; case S_IFDIR: error = -EPERM; @@ -1974,7 +1978,7 @@ asmlinkage long sys_mknodat(int dfd, const char __user *filename, int mode, } dput(dentry); } - mutex_unlock(&nd.dentry->d_inode->i_mutex); + mutex_unlock(&nd.path.dentry->d_inode->i_mutex); path_release(&nd); out: putname(tmp); @@ -2029,12 +2033,12 @@ asmlinkage long sys_mkdirat(int dfd, const char __user *pathname, int mode) if (IS_ERR(dentry)) goto out_unlock; - if (!IS_POSIXACL(nd.dentry->d_inode)) + if (!IS_POSIXACL(nd.path.dentry->d_inode)) mode &= ~current->fs->umask; - error = vfs_mkdir(nd.dentry->d_inode, dentry, mode); + error = vfs_mkdir(nd.path.dentry->d_inode, dentry, mode); dput(dentry); out_unlock: - mutex_unlock(&nd.dentry->d_inode->i_mutex); + mutex_unlock(&nd.path.dentry->d_inode->i_mutex); path_release(&nd); out: putname(tmp); @@ -2133,15 +2137,15 @@ static long do_rmdir(int dfd, const char __user *pathname) error = -EBUSY; goto exit1; } - mutex_lock_nested(&nd.dentry->d_inode->i_mutex, I_MUTEX_PARENT); + mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); dentry = lookup_hash(&nd); error = PTR_ERR(dentry); if (IS_ERR(dentry)) goto exit2; - error = vfs_rmdir(nd.dentry->d_inode, dentry); + error = vfs_rmdir(nd.path.dentry->d_inode, dentry); dput(dentry); exit2: - mutex_unlock(&nd.dentry->d_inode->i_mutex); + mutex_unlock(&nd.path.dentry->d_inode->i_mutex); exit1: path_release(&nd); exit: @@ -2209,7 +2213,7 @@ static long do_unlinkat(int dfd, const char __user *pathname) error = -EISDIR; if (nd.last_type != LAST_NORM) goto exit1; - mutex_lock_nested(&nd.dentry->d_inode->i_mutex, I_MUTEX_PARENT); + mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); dentry = lookup_hash(&nd); error = PTR_ERR(dentry); if (!IS_ERR(dentry)) { @@ -2219,11 +2223,11 @@ static long do_unlinkat(int dfd, const char __user *pathname) inode = dentry->d_inode; if (inode) atomic_inc(&inode->i_count); - error = vfs_unlink(nd.dentry->d_inode, dentry); + error = vfs_unlink(nd.path.dentry->d_inode, dentry); exit2: dput(dentry); } - mutex_unlock(&nd.dentry->d_inode->i_mutex); + mutex_unlock(&nd.path.dentry->d_inode->i_mutex); if (inode) iput(inode); /* truncate the inode here */ exit1: @@ -2300,10 +2304,10 @@ asmlinkage long sys_symlinkat(const char __user *oldname, if (IS_ERR(dentry)) goto out_unlock; - error = vfs_symlink(nd.dentry->d_inode, dentry, from, S_IALLUGO); + error = vfs_symlink(nd.path.dentry->d_inode, dentry, from, S_IALLUGO); dput(dentry); out_unlock: - mutex_unlock(&nd.dentry->d_inode->i_mutex); + mutex_unlock(&nd.path.dentry->d_inode->i_mutex); path_release(&nd); out: putname(to); @@ -2389,16 +2393,16 @@ asmlinkage long sys_linkat(int olddfd, const char __user *oldname, if (error) goto out; error = -EXDEV; - if (old_nd.mnt != nd.mnt) + if (old_nd.path.mnt != nd.path.mnt) goto out_release; new_dentry = lookup_create(&nd, 0); error = PTR_ERR(new_dentry); if (IS_ERR(new_dentry)) goto out_unlock; - error = vfs_link(old_nd.dentry, nd.dentry->d_inode, new_dentry); + error = vfs_link(old_nd.path.dentry, nd.path.dentry->d_inode, new_dentry); dput(new_dentry); out_unlock: - mutex_unlock(&nd.dentry->d_inode->i_mutex); + mutex_unlock(&nd.path.dentry->d_inode->i_mutex); out_release: path_release(&nd); out: @@ -2578,15 +2582,15 @@ static int do_rename(int olddfd, const char *oldname, goto exit1; error = -EXDEV; - if (oldnd.mnt != newnd.mnt) + if (oldnd.path.mnt != newnd.path.mnt) goto exit2; - old_dir = oldnd.dentry; + old_dir = oldnd.path.dentry; error = -EBUSY; if (oldnd.last_type != LAST_NORM) goto exit2; - new_dir = newnd.dentry; + new_dir = newnd.path.dentry; if (newnd.last_type != LAST_NORM) goto exit2; -- cgit v1.2.3