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Commit e8e96157 authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Linus Torvalds
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fuse: clean up execute permission checking 



Define a new function fuse_refresh_attributes() that conditionally refreshes
the attributes based on the validity timeout.

In fuse_permission() only refresh the attributes for checking the execute bits
if necessary.

Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c9c9d7df

fs/fuse/dir.c

+31 −18
Original line number Diff line number Diff line
@@ -694,6 +694,20 @@ static int fuse_do_getattr(struct inode *inode) 
	return err;

}



/*

 * Check if attributes are still valid, and if not send a GETATTR

 * request to refresh them.

 */

static int fuse_refresh_attributes(struct inode *inode)

{

	struct fuse_inode *fi = get_fuse_inode(inode);



	if (fi->i_time < get_jiffies_64())

		return fuse_do_getattr(inode);

	else

		return 0;

}



/*

 * Calling into a user-controlled filesystem gives the filesystem

 * daemon ptrace-like capabilities over the requester process.  This
@@ -770,7 +784,6 @@ static int fuse_access(struct inode *inode, int mask) 
static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)

{

	struct fuse_conn *fc = get_fuse_conn(inode);

	struct fuse_inode *fi = get_fuse_inode(inode);

	bool refreshed = false;

	int err = 0;
@@ -778,12 +791,11 @@ static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd) 
		return -EACCES;



	/*

	 * If attributes are needed, but are stale, refresh them

	 * before proceeding

	 * If attributes are needed, refresh them before proceeding

	 */

	if (((fc->flags & FUSE_DEFAULT_PERMISSIONS) || (mask & MAY_EXEC)) &&

	    fi->i_time < get_jiffies_64()) {

		err = fuse_do_getattr(inode);

	if ((fc->flags & FUSE_DEFAULT_PERMISSIONS) ||

	    ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) {

		err = fuse_refresh_attributes(inode);

		if (err)

			return err;
@@ -806,14 +818,17 @@ static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd) 
		   exist.  So if permissions are revoked this won't be

		   noticed immediately, only after the attribute

		   timeout has expired */



	} else {

		int mode = inode->i_mode;

		if ((mask & MAY_EXEC) && !S_ISDIR(mode) && !(mode & S_IXUGO))

	} else if (nd && (nd->flags & (LOOKUP_ACCESS | LOOKUP_CHDIR))) {

		err = fuse_access(inode, mask);

	} else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {

		if (!(inode->i_mode & S_IXUGO)) {

			if (refreshed)

				return -EACCES;



		if (nd && (nd->flags & (LOOKUP_ACCESS | LOOKUP_CHDIR)))

			return fuse_access(inode, mask);

			err = fuse_do_getattr(inode);

			if (!err && !(inode->i_mode & S_IXUGO))

				return -EACCES;

		}

	}

	return err;

}
@@ -1046,14 +1061,12 @@ static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry, 
	struct inode *inode = entry->d_inode;

	struct fuse_inode *fi = get_fuse_inode(inode);

	struct fuse_conn *fc = get_fuse_conn(inode);

	int err = 0;

	int err;



	if (!fuse_allow_task(fc, current))

		return -EACCES;



	if (fi->i_time < get_jiffies_64())

		err = fuse_do_getattr(inode);



	err = fuse_refresh_attributes(inode);

	if (!err) {

		generic_fillattr(inode, stat);

		stat->mode = fi->orig_i_mode;