Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761478AbXFQTNG (ORCPT ); Sun, 17 Jun 2007 15:13:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761200AbXFQTKK (ORCPT ); Sun, 17 Jun 2007 15:10:10 -0400 Received: from filer.fsl.cs.sunysb.edu ([130.245.126.2]:36875 "EHLO filer.fsl.cs.sunysb.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761133AbXFQTKA (ORCPT ); Sun, 17 Jun 2007 15:10:00 -0400 From: "Josef 'Jeff' Sipek" To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: akpm@linux-foundation.org, Erez Zadok , "Josef 'Jeff' Sipek" Subject: [PATCH 04/16] Unionfs: Set lower inodes correctly after branch management succeeds Date: Sun, 17 Jun 2007 15:09:11 -0400 Message-Id: <11821073631286-git-send-email-jsipek@cs.sunysb.edu> X-Mailer: git-send-email 1.5.2.rc1.165.gaf9b In-Reply-To: <11821073632989-git-send-email-jsipek@cs.sunysb.edu> References: <11821073632989-git-send-email-jsipek@cs.sunysb.edu> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4522 Lines: 120 From: Erez Zadok Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek --- fs/unionfs/super.c | 50 +++++++++++++++++++++++++++++++++++++++++++++----- 1 files changed, 45 insertions(+), 5 deletions(-) diff --git a/fs/unionfs/super.c b/fs/unionfs/super.c index fe02941..b3a5e64 100644 --- a/fs/unionfs/super.c +++ b/fs/unionfs/super.c @@ -335,7 +335,13 @@ found_insertion_point: new_branch, err); goto out; } - /* it's probably safe to check_mode the new branch to insert */ + /* + * It's probably safe to check_mode the new branch to insert. Note: + * we don't allow inserting branches which are unionfs's by + * themselves (check_branch returns EINVAL in that case). This is + * because this code base doesn't support stacking unionfs: the ODF + * code base supports that correctly. + */ if ((err = check_branch(&nd))) { printk(KERN_WARNING "unionfs: hidden directory " "\"%s\" is not a valid branch\n", optarg); @@ -400,15 +406,17 @@ static int unionfs_remount_fs(struct super_block *sb, int *flags, int i; char *optionstmp, *tmp_to_free; /* kstrdup'ed of "options" */ char *optname; - int cur_branches; /* no. of current branches */ - int new_branches; /* no. of branches actually left in the end */ + int cur_branches = 0; /* no. of current branches */ + int new_branches = 0; /* no. of branches actually left in the end */ int add_branches; /* est. no. of branches to add */ int del_branches; /* est. no. of branches to del */ int max_branches; /* max possible no. of branches */ struct unionfs_data *new_data = NULL, *tmp_data = NULL; struct path *new_lower_paths = NULL, *tmp_lower_paths = NULL; + struct inode **new_lower_inodes = NULL; int new_high_branch_id; /* new high branch ID */ int size; /* memory allocation size, temp var */ + int old_ibstart, old_ibend; unionfs_write_lock(sb); @@ -640,6 +648,14 @@ out_no_change: goto out_release; } + /* allocate space for new pointers to lower inodes */ + new_lower_inodes = kcalloc(new_branches, + sizeof(struct inode *), GFP_KERNEL); + if (!new_lower_inodes) { + err = -ENOMEM; + goto out_release; + } + /* * OK, just before we actually put the new set of branches in place, * we need to ensure that our own f/s has no dirty objects left. @@ -660,7 +676,7 @@ out_no_change: * fsync_super() which would not have returned until all dirty pages * were flushed. * - * But do w have to worry about locked pages? Is there any chance + * But do we have to worry about locked pages? Is there any chance * that in here we'll get locked pages? * * XXX: what about pages mapped into pagetables? Are these pages @@ -687,8 +703,31 @@ out_no_change: i = sbmax(sb); /* save no. of branches to release at end */ sbend(sb) = new_branches - 1; set_dbend(sb->s_root, new_branches - 1); + old_ibstart = ibstart(sb->s_root->d_inode); + old_ibend = ibend(sb->s_root->d_inode); + ibend(sb->s_root->d_inode) = new_branches - 1; UNIONFS_D(sb->s_root)->bcount = new_branches; - new_branches = i; /* no. of branches to release below */ + new_branches = i; /* no. of branches to release below */ + + /* + * Update lower inodes: 3 steps + * 1. grab ref on all new lower inodes + */ + for (i=dbstart(sb->s_root); i<=dbend(sb->s_root); i++) { + struct dentry *lower_dentry = + unionfs_lower_dentry_idx(sb->s_root, i); + atomic_inc(&lower_dentry->d_inode->i_count); + new_lower_inodes[i] = lower_dentry->d_inode; + } + /* 2. release reference on all older lower inodes */ + for (i=old_ibstart; i<=old_ibend; i++) { + iput(unionfs_lower_inode_idx(sb->s_root->d_inode, i)); + unionfs_set_lower_inode_idx(sb->s_root->d_inode, i, NULL); + } + kfree(UNIONFS_I(sb->s_root->d_inode)->lower_inodes); + /* 3. update root dentry's inode to new lower_inodes array */ + UNIONFS_I(sb->s_root->d_inode)->lower_inodes = new_lower_inodes; + new_lower_inodes = NULL; /* maxbytes may have changed */ sb->s_maxbytes = unionfs_lower_super_idx(sb, 0)->s_maxbytes; @@ -723,6 +762,7 @@ out_free: kfree(tmp_data); kfree(new_lower_paths); kfree(new_data); + kfree(new_lower_inodes); out_error: unionfs_write_unlock(sb); return err; -- 1.5.2.rc1.165.gaf9b - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/