Commit 482928d5 authored by Al Viro's avatar Al Viro
Browse files

Fix f_flags/f_mode in case of lookup_instantiate_filp() from open(pathname, 3) 



Just set f_flags when shoving struct file into nameidata; don't
postpone that until __dentry_open().  do_filp_open() has correct
value; lookup_instantiate_filp() doesn't - we lose the difference
between O_RDWR and 3 by that point.

We still set .intent.open.flags, so no fs code needs to be changed.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 628ff7c1

fs/internal.h

+7 −0
Original line number Diff line number Diff line
@@ -85,3 +85,10 @@ extern struct file *get_empty_filp(void); 
 * super.c

 */

extern int do_remount_sb(struct super_block *, int, void *, int);



/*

 * open.c

 */

struct nameidata;

extern struct file *nameidata_to_filp(struct nameidata *);

extern void release_open_intent(struct nameidata *);

fs/namei.c

+4 −2
Original line number Diff line number Diff line
@@ -1640,6 +1640,7 @@ struct file *do_filp_open(int dfd, const char *pathname, 
		if (filp == NULL)

			return ERR_PTR(-ENFILE);

		nd.intent.open.file = filp;

		filp->f_flags = open_flag;

		nd.intent.open.flags = flag;

		nd.intent.open.create_mode = 0;

		error = do_path_lookup(dfd, pathname,
@@ -1685,6 +1686,7 @@ struct file *do_filp_open(int dfd, const char *pathname, 
	if (filp == NULL)

		goto exit_parent;

	nd.intent.open.file = filp;

	filp->f_flags = open_flag;

	nd.intent.open.flags = flag;

	nd.intent.open.create_mode = mode;

	dir = nd.path.dentry;
@@ -1725,7 +1727,7 @@ do_last: 
			mnt_drop_write(nd.path.mnt);

			goto exit;

		}

		filp = nameidata_to_filp(&nd, open_flag);

		filp = nameidata_to_filp(&nd);

		mnt_drop_write(nd.path.mnt);

		if (nd.root.mnt)

			path_put(&nd.root);
@@ -1789,7 +1791,7 @@ ok: 
			mnt_drop_write(nd.path.mnt);

		goto exit;

	}

	filp = nameidata_to_filp(&nd, open_flag);

	filp = nameidata_to_filp(&nd);

	if (!IS_ERR(filp)) {

		error = ima_path_check(&filp->f_path, filp->f_mode &

			       (MAY_READ | MAY_WRITE | MAY_EXEC));

fs/open.c

+6 −7
Original line number Diff line number Diff line
@@ -821,15 +821,14 @@ static inline int __get_file_write_access(struct inode *inode, 
}



static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,

					int flags, struct file *f,

					struct file *f,

					int (*open)(struct inode *, struct file *),

					const struct cred *cred)

{

	struct inode *inode;

	int error;



	f->f_flags = flags;

	f->f_mode = (__force fmode_t)((flags+1) & O_ACCMODE) | FMODE_LSEEK |

	f->f_mode = (__force fmode_t)((f->f_flags+1) & O_ACCMODE) | FMODE_LSEEK |

				FMODE_PREAD | FMODE_PWRITE;

	inode = dentry->d_inode;

	if (f->f_mode & FMODE_WRITE) {
@@ -930,7 +929,6 @@ struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry 
	if (IS_ERR(dentry))

		goto out_err;

	nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt),

					     nd->intent.open.flags - 1,

					     nd->intent.open.file,

					     open, cred);

out:
@@ -949,7 +947,7 @@ EXPORT_SYMBOL_GPL(lookup_instantiate_filp); 
 *

 * Note that this function destroys the original nameidata

 */

struct file *nameidata_to_filp(struct nameidata *nd, int flags)

struct file *nameidata_to_filp(struct nameidata *nd)

{

	const struct cred *cred = current_cred();

	struct file *filp;
@@ -958,7 +956,7 @@ struct file *nameidata_to_filp(struct nameidata *nd, int flags) 
	filp = nd->intent.open.file;

	/* Has the filesystem initialised the file for us? */

	if (filp->f_path.dentry == NULL)

		filp = __dentry_open(nd->path.dentry, nd->path.mnt, flags, filp,

		filp = __dentry_open(nd->path.dentry, nd->path.mnt, filp,

				     NULL, cred);

	else

		path_put(&nd->path);
@@ -997,7 +995,8 @@ struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags, 
		return ERR_PTR(error);

	}



	return __dentry_open(dentry, mnt, flags, f, NULL, cred);

	f->f_flags = flags;

	return __dentry_open(dentry, mnt, f, NULL, cred);

}

EXPORT_SYMBOL(dentry_open);

include/linux/namei.h

+0 −2
Original line number Diff line number Diff line
@@ -72,8 +72,6 @@ extern int vfs_path_lookup(struct dentry *, struct vfsmount *, 


extern struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,

		int (*open)(struct inode *, struct file *));

extern struct file *nameidata_to_filp(struct nameidata *nd, int flags);

extern void release_open_intent(struct nameidata *);



extern struct dentry *lookup_one_len(const char *, struct dentry *, int);

CRA Git | Maintained and supported by SUSTech CRA and CCSE