From mboxrd@z Thu Jan 1 00:00:00 1970 From: Amir Goldstein Subject: [PATCH v6 3/9] ovl: allocate anonymous devs for lowerdirs Date: Wed, 1 Nov 2017 22:22:47 +0200 Message-ID: <1509567773-25590-4-git-send-email-amir73il@gmail.com> References: <1509567773-25590-1-git-send-email-amir73il@gmail.com> Return-path: Received: from mail-wr0-f196.google.com ([209.85.128.196]:57267 "EHLO mail-wr0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755040AbdKAUWQ (ORCPT ); Wed, 1 Nov 2017 16:22:16 -0400 Received: by mail-wr0-f196.google.com with SMTP id r79so2995859wrb.13 for ; Wed, 01 Nov 2017 13:22:15 -0700 (PDT) In-Reply-To: <1509567773-25590-1-git-send-email-amir73il@gmail.com> Sender: linux-unionfs-owner@vger.kernel.org List-Id: linux-unionfs@vger.kernel.org To: Miklos Szeredi Cc: Chandan Rajendra , Vivek Goyal , linux-unionfs@vger.kernel.org From: Chandan Rajendra Generate unique values of st_dev per lower layer for non-samefs overlay mount. The unique values are obtained by allocating anonymous bdevs for each of the lowerdirs in the overlayfs instance. The anonymous bdev is going to be returned by stat(2) for lowerdir non-dir entries in non-samefs case. [amir: split from ovl_getattr() and re-structure patches] Signed-off-by: Chandan Rajendra Signed-off-by: Amir Goldstein --- fs/overlayfs/ovl_entry.h | 1 + fs/overlayfs/super.c | 18 ++++++++++++++++-- 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h index 1e28329b5db8..93eb6a044dd2 100644 --- a/fs/overlayfs/ovl_entry.h +++ b/fs/overlayfs/ovl_entry.h @@ -19,6 +19,7 @@ struct ovl_config { struct ovl_layer { struct vfsmount *mnt; + dev_t pseudo_dev; }; struct ovl_path { diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index e6e13d9588d1..323dfd7a0236 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -219,8 +219,10 @@ static void ovl_put_super(struct super_block *sb) if (ufs->upper_mnt && ufs->upperdir_locked) ovl_inuse_unlock(ufs->upper_mnt->mnt_root); mntput(ufs->upper_mnt); - for (i = 0; i < ufs->numlower; i++) + for (i = 0; i < ufs->numlower; i++) { mntput(ufs->lower_layers[i].mnt); + free_anon_bdev(ufs->lower_layers[i].pseudo_dev); + } kfree(ufs->lower_layers); kfree(ufs->config.lowerdir); @@ -1032,11 +1034,19 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) goto out_put_workdir; for (i = 0; i < numlower; i++) { struct vfsmount *mnt; + dev_t dev; + + err = get_anon_bdev(&dev); + if (err) { + pr_err("overlayfs: failed to get anonymous bdev for lowerpath\n"); + goto out_put_lower_layers; + } mnt = clone_private_mount(&stack[i]); err = PTR_ERR(mnt); if (IS_ERR(mnt)) { pr_err("overlayfs: failed to clone lowerpath\n"); + free_anon_bdev(dev); goto out_put_lower_layers; } /* @@ -1046,6 +1056,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) mnt->mnt_flags |= MNT_READONLY | MNT_NOATIME; ufs->lower_layers[ufs->numlower].mnt = mnt; + ufs->lower_layers[ufs->numlower].pseudo_dev = dev; ufs->numlower++; /* Check if all lower layers are on same sb */ @@ -1160,8 +1171,11 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) out_free_oe: kfree(oe); out_put_lower_layers: - for (i = 0; i < ufs->numlower; i++) + for (i = 0; i < ufs->numlower; i++) { + if (ufs->lower_layers[i].mnt) + free_anon_bdev(ufs->lower_layers[i].pseudo_dev); mntput(ufs->lower_layers[i].mnt); + } kfree(ufs->lower_layers); out_put_workdir: dput(ufs->workdir); -- 2.7.4