From: Josef "Jeff" Sipek <jsipek@xxxxxxxxxxxxx> This patch contains the ioctls to increase the union generation and to query which branch a file exists on. Signed-off-by: Josef "Jeff" Sipek <jsipek@xxxxxxxxxxxxx> Signed-off-by: David Quigley <dquigley@xxxxxxxxxxxxxxxxx> Signed-off-by: Erez Zadok <ezk@xxxxxxxxxxxxx> --- fs/unionfs/branchman.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 81 insertions(+), 0 deletions(-) diff --git a/fs/unionfs/branchman.c b/fs/unionfs/branchman.c new file mode 100644 index 0000000..168c5d5 --- /dev/null +++ b/fs/unionfs/branchman.c @@ -0,0 +1,81 @@ +/* + * Copyright (c) 2003-2006 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2006 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2006 Stony Brook University + * Copyright (c) 2003-2006 The Research Foundation of State University of New York + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +/* increase the superblock generation count; effectively invalidating every + * upper inode, dentry and file object */ +int unionfs_ioctl_incgen(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct super_block *sb; + int gen; + + sb = file->f_dentry->d_sb; + + unionfs_write_lock(sb); + + gen = atomic_inc_return(&UNIONFS_SB(sb)->generation); + + atomic_set(&UNIONFS_D(sb->s_root)->generation, gen); + atomic_set(&UNIONFS_I(sb->s_root->d_inode)->generation, gen); + + unionfs_write_unlock(sb); + + return gen; +} + +/* return to userspace the branch indices containing the file in question + * + * We use fd_set and therefore we are limited to the number of the branches + * to FD_SETSIZE, which is currently 1024 - plenty for most people + */ +int unionfs_ioctl_queryfile(struct file *file, unsigned int cmd, + unsigned long arg) +{ + int err = 0; + fd_set branchlist; + + int bstart = 0, bend = 0, bindex = 0; + struct dentry *dentry, *hidden_dentry; + + dentry = file->f_dentry; + lock_dentry(dentry); + if ((err = unionfs_partial_lookup(dentry))) + goto out; + bstart = dbstart(dentry); + bend = dbend(dentry); + + FD_ZERO(&branchlist); + + for (bindex = bstart; bindex <= bend; bindex++) { + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); + if (!hidden_dentry) + continue; + if (hidden_dentry->d_inode) + FD_SET(bindex, &branchlist); + } + + err = copy_to_user((void __user *)arg, &branchlist, sizeof(fd_set)); + if (err) + err = -EFAULT; + +out: + unlock_dentry(dentry); + return err < 0 ? err : bend; +} + -- 1.4.3.3 - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html