Commit f7ad3c6b authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Al Viro
Browse files

vfs: add helpers to get root and pwd 



Add three helpers that retrieve a refcounted copy of the root and cwd
from the supplied fs_struct.

 get_fs_root()
 get_fs_pwd()
 get_fs_root_and_pwd()

Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 542ce7a9

fs/cachefiles/daemon.c

+2 −12
Original line number Diff line number Diff line
@@ -552,7 +552,6 @@ static int cachefiles_daemon_tag(struct cachefiles_cache *cache, char *args) 
 */

static int cachefiles_daemon_cull(struct cachefiles_cache *cache, char *args)

{

	struct fs_struct *fs;

	struct path path;

	const struct cred *saved_cred;

	int ret;
@@ -573,11 +572,7 @@ static int cachefiles_daemon_cull(struct cachefiles_cache *cache, char *args) 
	}



	/* extract the directory dentry from the cwd */

	fs = current->fs;

	read_lock(&fs->lock);

	path = fs->pwd;

	path_get(&path);

	read_unlock(&fs->lock);

	get_fs_pwd(current->fs, &path);



	if (!S_ISDIR(path.dentry->d_inode->i_mode))

		goto notdir;
@@ -629,7 +624,6 @@ inval: 
 */

static int cachefiles_daemon_inuse(struct cachefiles_cache *cache, char *args)

{

	struct fs_struct *fs;

	struct path path;

	const struct cred *saved_cred;

	int ret;
@@ -650,11 +644,7 @@ static int cachefiles_daemon_inuse(struct cachefiles_cache *cache, char *args) 
	}



	/* extract the directory dentry from the cwd */

	fs = current->fs;

	read_lock(&fs->lock);

	path = fs->pwd;

	path_get(&path);

	read_unlock(&fs->lock);

	get_fs_pwd(current->fs, &path);



	if (!S_ISDIR(path.dentry->d_inode->i_mode))

		goto notdir;

fs/dcache.c

+2 −10
Original line number Diff line number Diff line
@@ -2014,10 +2014,7 @@ char *d_path(const struct path *path, char *buf, int buflen) 
	if (path->dentry->d_op && path->dentry->d_op->d_dname)

		return path->dentry->d_op->d_dname(path->dentry, buf, buflen);



	read_lock(&current->fs->lock);

	root = current->fs->root;

	path_get(&root);

	read_unlock(&current->fs->lock);

	get_fs_root(current->fs, &root);

	spin_lock(&dcache_lock);

	tmp = root;

	res = __d_path(path, &tmp, buf, buflen);
@@ -2129,12 +2126,7 @@ SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size) 
	if (!page)

		return -ENOMEM;



	read_lock(&current->fs->lock);

	pwd = current->fs->pwd;

	path_get(&pwd);

	root = current->fs->root;

	path_get(&root);

	read_unlock(&current->fs->lock);

	get_fs_root_and_pwd(current->fs, &root, &pwd);



	error = -ENOENT;

	spin_lock(&dcache_lock);

fs/fs_struct.c

+1 −6
Original line number Diff line number Diff line
@@ -106,12 +106,7 @@ struct fs_struct *copy_fs_struct(struct fs_struct *old) 
		fs->in_exec = 0;

		rwlock_init(&fs->lock);

		fs->umask = old->umask;

		read_lock(&old->lock);

		fs->root = old->root;

		path_get(&old->root);

		fs->pwd = old->pwd;

		path_get(&old->pwd);

		read_unlock(&old->lock);

		get_fs_root_and_pwd(old, &fs->root, &fs->pwd);

	}

	return fs;

}

fs/namei.c

+3 −12
Original line number Diff line number Diff line
@@ -483,13 +483,8 @@ ok: 


static __always_inline void set_root(struct nameidata *nd)

{

	if (!nd->root.mnt) {

		struct fs_struct *fs = current->fs;

		read_lock(&fs->lock);

		nd->root = fs->root;

		path_get(&nd->root);

		read_unlock(&fs->lock);

	}

	if (!nd->root.mnt)

		get_fs_root(current->fs, &nd->root);

}



static int link_path_walk(const char *, struct nameidata *);
@@ -1015,11 +1010,7 @@ static int path_init(int dfd, const char *name, unsigned int flags, struct namei 
		nd->path = nd->root;

		path_get(&nd->root);

	} else if (dfd == AT_FDCWD) {

		struct fs_struct *fs = current->fs;

		read_lock(&fs->lock);

		nd->path = fs->pwd;

		path_get(&fs->pwd);

		read_unlock(&fs->lock);

		get_fs_pwd(current->fs, &nd->path);

	} else {

		struct dentry *dentry;

fs/namespace.c

+1 −4
Original line number Diff line number Diff line
@@ -2213,10 +2213,7 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root, 
		goto out1;

	}



	read_lock(&current->fs->lock);

	root = current->fs->root;

	path_get(&current->fs->root);

	read_unlock(&current->fs->lock);

	get_fs_root(current->fs, &root);

	down_write(&namespace_sem);

	mutex_lock(&old.dentry->d_inode->i_mutex);

	error = -EINVAL;

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