Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs (1a892b48) · Commits · e / devices / android_kernel_fairphone_FP3

fs/namei.c

+25 −0

Original line number	Original line	Diff line number	Diff line
	@@ -4668,6 +4668,31 @@ int generic_readlink(struct dentry dentry, char __user buffer, int buflen)
	}		}
	EXPORT_SYMBOL(generic_readlink);		EXPORT_SYMBOL(generic_readlink);

			/**
			* vfs_get_link - get symlink body
			* @dentry: dentry on which to get symbolic link
			* @done: caller needs to free returned data with this
			*
			* Calls security hook and i_op->get_link() on the supplied inode.
			*
			* It does not touch atime. That's up to the caller if necessary.
			*
			* Does not work on "special" symlinks like /proc/$$/fd/N
			*/
			const char vfs_get_link(struct dentry dentry, struct delayed_call *done)
			{
			const char *res = ERR_PTR(-EINVAL);
			struct inode *inode = d_inode(dentry);

			if (d_is_symlink(dentry)) {
			res = ERR_PTR(security_inode_readlink(dentry));
			if (!res)
			res = inode->i_op->get_link(dentry, inode, done);
			}
			return res;
			}
			EXPORT_SYMBOL(vfs_get_link);

	/* get the link contents into pagecache */		/* get the link contents into pagecache */
	const char page_get_link(struct dentry dentry, struct inode *inode,		const char page_get_link(struct dentry dentry, struct inode *inode,
	struct delayed_call *callback)		struct delayed_call *callback)

fs/overlayfs/copy_up.c

+20 −47

Original line number	Original line	Diff line number	Diff line
	@@ -57,6 +57,7 @@ int ovl_copy_xattr(struct dentry old, struct dentry new)
	ssize_t list_size, size, value_size = 0;		ssize_t list_size, size, value_size = 0;
	char buf, name, *value = NULL;		char buf, name, *value = NULL;
	int uninitialized_var(error);		int uninitialized_var(error);
			size_t slen;

	if (!(old->d_inode->i_opflags & IOP_XATTR) \|\|		if (!(old->d_inode->i_opflags & IOP_XATTR) \|\|
	!(new->d_inode->i_opflags & IOP_XATTR))		!(new->d_inode->i_opflags & IOP_XATTR))
	@@ -79,7 +80,16 @@ int ovl_copy_xattr(struct dentry old, struct dentry new)
	goto out;		goto out;
	}		}

	for (name = buf; name < (buf + list_size); name += strlen(name) + 1) {		for (name = buf; list_size; name += slen) {
			slen = strnlen(name, list_size) + 1;

			/* underlying fs providing us with an broken xattr list? */
			if (WARN_ON(slen > list_size)) {
			error = -EIO;
			break;
			}
			list_size -= slen;

	if (ovl_is_private_xattr(name))		if (ovl_is_private_xattr(name))
	continue;		continue;
	retry:		retry:
	@@ -174,40 +184,6 @@ static int ovl_copy_up_data(struct path old, struct path new, loff_t len)
	return error;		return error;
	}		}

	static char ovl_read_symlink(struct dentry realdentry)
	{
	int res;
	char *buf;
	struct inode *inode = realdentry->d_inode;
	mm_segment_t old_fs;

	res = -EINVAL;
	if (!inode->i_op->readlink)
	goto err;

	res = -ENOMEM;
	buf = (char *) __get_free_page(GFP_KERNEL);
	if (!buf)
	goto err;

	old_fs = get_fs();
	set_fs(get_ds());
	/* The cast to a user pointer is valid due to the set_fs() */
	res = inode->i_op->readlink(realdentry,
	(char __user *)buf, PAGE_SIZE - 1);
	set_fs(old_fs);
	if (res < 0) {
	free_page((unsigned long) buf);
	goto err;
	}
	buf[res] = '\0';

	return buf;

	err:
	return ERR_PTR(res);
	}

	static int ovl_set_timestamps(struct dentry upperdentry, struct kstat stat)		static int ovl_set_timestamps(struct dentry upperdentry, struct kstat stat)
	{		{
	struct iattr attr = {		struct iattr attr = {
	@@ -354,19 +330,20 @@ static int ovl_copy_up_locked(struct dentry workdir, struct dentry upperdir,
	int ovl_copy_up_one(struct dentry parent, struct dentry dentry,		int ovl_copy_up_one(struct dentry parent, struct dentry dentry,
	struct path lowerpath, struct kstat stat)		struct path lowerpath, struct kstat stat)
	{		{
			DEFINE_DELAYED_CALL(done);
	struct dentry *workdir = ovl_workdir(dentry);		struct dentry *workdir = ovl_workdir(dentry);
	int err;		int err;
	struct kstat pstat;		struct kstat pstat;
	struct path parentpath;		struct path parentpath;
			struct dentry *lowerdentry = lowerpath->dentry;
	struct dentry *upperdir;		struct dentry *upperdir;
	struct dentry *upperdentry;		struct dentry *upperdentry;
	const struct cred *old_cred;		const char *link = NULL;
	char *link = NULL;

	if (WARN_ON(!workdir))		if (WARN_ON(!workdir))
	return -EROFS;		return -EROFS;

	ovl_do_check_copy_up(lowerpath->dentry);		ovl_do_check_copy_up(lowerdentry);

	ovl_path_upper(parent, &parentpath);		ovl_path_upper(parent, &parentpath);
	upperdir = parentpath.dentry;		upperdir = parentpath.dentry;
	@@ -376,13 +353,11 @@ int ovl_copy_up_one(struct dentry parent, struct dentry dentry,
	return err;		return err;

	if (S_ISLNK(stat->mode)) {		if (S_ISLNK(stat->mode)) {
	link = ovl_read_symlink(lowerpath->dentry);		link = vfs_get_link(lowerdentry, &done);
	if (IS_ERR(link))		if (IS_ERR(link))
	return PTR_ERR(link);		return PTR_ERR(link);
	}		}

	old_cred = ovl_override_creds(dentry->d_sb);

	err = -EIO;		err = -EIO;
	if (lock_rename(workdir, upperdir) != NULL) {		if (lock_rename(workdir, upperdir) != NULL) {
	pr_err("overlayfs: failed to lock workdir+upperdir\n");		pr_err("overlayfs: failed to lock workdir+upperdir\n");
	@@ -403,19 +378,16 @@ int ovl_copy_up_one(struct dentry parent, struct dentry dentry,
	}		}
	out_unlock:		out_unlock:
	unlock_rename(workdir, upperdir);		unlock_rename(workdir, upperdir);
	revert_creds(old_cred);		do_delayed_call(&done);

	if (link)
	free_page((unsigned long) link);

	return err;		return err;
	}		}

	int ovl_copy_up(struct dentry *dentry)		int ovl_copy_up(struct dentry *dentry)
	{		{
	int err;		int err = 0;
			const struct cred *old_cred = ovl_override_creds(dentry->d_sb);

	err = 0;
	while (!err) {		while (!err) {
	struct dentry *next;		struct dentry *next;
	struct dentry *parent;		struct dentry *parent;
	@@ -447,6 +419,7 @@ int ovl_copy_up(struct dentry *dentry)
	dput(parent);		dput(parent);
	dput(next);		dput(next);
	}		}
			revert_creds(old_cred);

	return err;		return err;
	}		}

fs/overlayfs/dir.c

+4 −1

Original line number	Original line	Diff line number	Diff line
	@@ -14,6 +14,7 @@
	#include <linux/cred.h>		#include <linux/cred.h>
	#include <linux/posix_acl.h>		#include <linux/posix_acl.h>
	#include <linux/posix_acl_xattr.h>		#include <linux/posix_acl_xattr.h>
			#include <linux/atomic.h>
	#include "overlayfs.h"		#include "overlayfs.h"

	void ovl_cleanup(struct inode wdir, struct dentry wdentry)		void ovl_cleanup(struct inode wdir, struct dentry wdentry)
	@@ -37,8 +38,10 @@ struct dentry ovl_lookup_temp(struct dentry workdir, struct dentry *dentry)
	{		{
	struct dentry *temp;		struct dentry *temp;
	char name[20];		char name[20];
			static atomic_t temp_id = ATOMIC_INIT(0);

	snprintf(name, sizeof(name), "#%lx", (unsigned long) dentry);		/* counter is allowed to wrap, since temp dentries are ephemeral */
			snprintf(name, sizeof(name), "#%x", atomic_inc_return(&temp_id));

	temp = lookup_one_len(name, workdir, strlen(name));		temp = lookup_one_len(name, workdir, strlen(name));
	if (!IS_ERR(temp) && temp->d_inode) {		if (!IS_ERR(temp) && temp->d_inode) {

fs/overlayfs/inode.c

+10 −34

Original line number	Original line	Diff line number	Diff line
	@@ -19,6 +19,7 @@ static int ovl_copy_up_truncate(struct dentry *dentry)
	struct dentry *parent;		struct dentry *parent;
	struct kstat stat;		struct kstat stat;
	struct path lowerpath;		struct path lowerpath;
			const struct cred *old_cred;

	parent = dget_parent(dentry);		parent = dget_parent(dentry);
	err = ovl_copy_up(parent);		err = ovl_copy_up(parent);
	@@ -26,12 +27,14 @@ static int ovl_copy_up_truncate(struct dentry *dentry)
	goto out_dput_parent;		goto out_dput_parent;

	ovl_path_lower(dentry, &lowerpath);		ovl_path_lower(dentry, &lowerpath);
	err = vfs_getattr(&lowerpath, &stat);
	if (err)
	goto out_dput_parent;

			old_cred = ovl_override_creds(dentry->d_sb);
			err = vfs_getattr(&lowerpath, &stat);
			if (!err) {
	stat.size = 0;		stat.size = 0;
	err = ovl_copy_up_one(parent, dentry, &lowerpath, &stat);		err = ovl_copy_up_one(parent, dentry, &lowerpath, &stat);
			}
			revert_creds(old_cred);

	out_dput_parent:		out_dput_parent:
	dput(parent);		dput(parent);
	@@ -153,45 +156,18 @@ static const char ovl_get_link(struct dentry dentry,
	struct inode *inode,		struct inode *inode,
	struct delayed_call *done)		struct delayed_call *done)
	{		{
	struct dentry *realdentry;
	struct inode *realinode;
	const struct cred *old_cred;		const struct cred *old_cred;
	const char *p;		const char *p;

	if (!dentry)		if (!dentry)
	return ERR_PTR(-ECHILD);		return ERR_PTR(-ECHILD);

	realdentry = ovl_dentry_real(dentry);
	realinode = realdentry->d_inode;

	if (WARN_ON(!realinode->i_op->get_link))
	return ERR_PTR(-EPERM);

	old_cred = ovl_override_creds(dentry->d_sb);		old_cred = ovl_override_creds(dentry->d_sb);
	p = realinode->i_op->get_link(realdentry, realinode, done);		p = vfs_get_link(ovl_dentry_real(dentry), done);
	revert_creds(old_cred);		revert_creds(old_cred);
	return p;		return p;
	}		}

	static int ovl_readlink(struct dentry dentry, char __user buf, int bufsiz)
	{
	struct path realpath;
	struct inode *realinode;
	const struct cred *old_cred;
	int err;

	ovl_path_real(dentry, &realpath);
	realinode = realpath.dentry->d_inode;

	if (!realinode->i_op->readlink)
	return -EINVAL;

	old_cred = ovl_override_creds(dentry->d_sb);
	err = realinode->i_op->readlink(realpath.dentry, buf, bufsiz);
	revert_creds(old_cred);
	return err;
	}

	bool ovl_is_private_xattr(const char *name)		bool ovl_is_private_xattr(const char *name)
	{		{
	return strncmp(name, OVL_XATTR_PREFIX,		return strncmp(name, OVL_XATTR_PREFIX,
	@@ -375,7 +351,7 @@ static const struct inode_operations ovl_file_inode_operations = {
	static const struct inode_operations ovl_symlink_inode_operations = {		static const struct inode_operations ovl_symlink_inode_operations = {
	.setattr = ovl_setattr,		.setattr = ovl_setattr,
	.get_link = ovl_get_link,		.get_link = ovl_get_link,
	.readlink = ovl_readlink,		.readlink = generic_readlink,
	.getattr = ovl_getattr,		.getattr = ovl_getattr,
	.listxattr = ovl_listxattr,		.listxattr = ovl_listxattr,
	.update_time = ovl_update_time,		.update_time = ovl_update_time,

fs/overlayfs/super.c

+22 −11

Original line number	Original line	Diff line number	Diff line
	@@ -273,12 +273,11 @@ static bool ovl_is_opaquedir(struct dentry *dentry)
	{		{
	int res;		int res;
	char val;		char val;
	struct inode *inode = dentry->d_inode;

	if (!S_ISDIR(inode->i_mode) \|\| !(inode->i_opflags & IOP_XATTR))		if (!d_is_dir(dentry))
	return false;		return false;

	res = __vfs_getxattr(dentry, inode, OVL_XATTR_OPAQUE, &val, 1);		res = vfs_getxattr(dentry, OVL_XATTR_OPAQUE, &val, 1);
	if (res == 1 && val == 'y')		if (res == 1 && val == 'y')
	return true;		return true;

	@@ -419,16 +418,12 @@ static bool ovl_dentry_weird(struct dentry *dentry)
	DCACHE_OP_COMPARE);		DCACHE_OP_COMPARE);
	}		}

	static inline struct dentry ovl_lookup_real(struct super_block ovl_sb,		static inline struct dentry ovl_lookup_real(struct dentry dir,
	struct dentry *dir,
	const struct qstr *name)		const struct qstr *name)
	{		{
	const struct cred *old_cred;
	struct dentry *dentry;		struct dentry *dentry;

	old_cred = ovl_override_creds(ovl_sb);
	dentry = lookup_one_len_unlocked(name->name, dir, name->len);		dentry = lookup_one_len_unlocked(name->name, dir, name->len);
	revert_creds(old_cred);

	if (IS_ERR(dentry)) {		if (IS_ERR(dentry)) {
	if (PTR_ERR(dentry) == -ENOENT)		if (PTR_ERR(dentry) == -ENOENT)
	@@ -469,6 +464,7 @@ struct dentry ovl_lookup(struct inode dir, struct dentry *dentry,
	unsigned int flags)		unsigned int flags)
	{		{
	struct ovl_entry *oe;		struct ovl_entry *oe;
			const struct cred *old_cred;
	struct ovl_entry *poe = dentry->d_parent->d_fsdata;		struct ovl_entry *poe = dentry->d_parent->d_fsdata;
	struct path *stack = NULL;		struct path *stack = NULL;
	struct dentry upperdir, upperdentry = NULL;		struct dentry upperdir, upperdentry = NULL;
	@@ -479,9 +475,10 @@ struct dentry ovl_lookup(struct inode dir, struct dentry *dentry,
	unsigned int i;		unsigned int i;
	int err;		int err;

			old_cred = ovl_override_creds(dentry->d_sb);
	upperdir = ovl_upperdentry_dereference(poe);		upperdir = ovl_upperdentry_dereference(poe);
	if (upperdir) {		if (upperdir) {
	this = ovl_lookup_real(dentry->d_sb, upperdir, &dentry->d_name);		this = ovl_lookup_real(upperdir, &dentry->d_name);
	err = PTR_ERR(this);		err = PTR_ERR(this);
	if (IS_ERR(this))		if (IS_ERR(this))
	goto out;		goto out;
	@@ -514,8 +511,7 @@ struct dentry ovl_lookup(struct inode dir, struct dentry *dentry,
	bool opaque = false;		bool opaque = false;
	struct path lowerpath = poe->lowerstack[i];		struct path lowerpath = poe->lowerstack[i];

	this = ovl_lookup_real(dentry->d_sb,		this = ovl_lookup_real(lowerpath.dentry, &dentry->d_name);
	lowerpath.dentry, &dentry->d_name);
	err = PTR_ERR(this);		err = PTR_ERR(this);
	if (IS_ERR(this)) {		if (IS_ERR(this)) {
	/*		/*
	@@ -588,6 +584,7 @@ struct dentry ovl_lookup(struct inode dir, struct dentry *dentry,
	ovl_copyattr(realdentry->d_inode, inode);		ovl_copyattr(realdentry->d_inode, inode);
	}		}

			revert_creds(old_cred);
	oe->opaque = upperopaque;		oe->opaque = upperopaque;
	oe->__upperdentry = upperdentry;		oe->__upperdentry = upperdentry;
	memcpy(oe->lowerstack, stack, sizeof(struct path) * ctr);		memcpy(oe->lowerstack, stack, sizeof(struct path) * ctr);
	@@ -606,6 +603,7 @@ struct dentry ovl_lookup(struct inode dir, struct dentry *dentry,
	out_put_upper:		out_put_upper:
	dput(upperdentry);		dput(upperdentry);
	out:		out:
			revert_creds(old_cred);
	return ERR_PTR(err);		return ERR_PTR(err);
	}		}

	@@ -834,6 +832,19 @@ static struct dentry ovl_workdir_create(struct vfsmount mnt,
	if (err)		if (err)
	goto out_dput;		goto out_dput;

			/*
			* Try to remove POSIX ACL xattrs from workdir. We are good if:
			*
			* a) success (there was a POSIX ACL xattr and was removed)
			* b) -ENODATA (there was no POSIX ACL xattr)
			* c) -EOPNOTSUPP (POSIX ACL xattrs are not supported)
			*
			* There are various other error values that could effectively
			* mean that the xattr doesn't exist (e.g. -ERANGE is returned
			* if the xattr name is too long), but the set of filesystems
			* allowed as upper are limited to "normal" ones, where checking
			* for the above two errors is sufficient.
			*/
	err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_DEFAULT);		err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_DEFAULT);
	if (err && err != -ENODATA && err != -EOPNOTSUPP)		if (err && err != -ENODATA && err != -EOPNOTSUPP)
	goto out_dput;		goto out_dput;