From c0d91fb9101100b8c13779b95f70b2ef75b54526 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Thu, 9 Nov 2017 10:23:28 +0100 Subject: [PATCH] ovl: split out ovl_get_lower_layers() from ovl_fill_super() Signed-off-by: Miklos Szeredi --- fs/overlayfs/super.c | 90 +++++++++++++++++++++++++------------------- 1 file changed, 52 insertions(+), 38 deletions(-) diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index aadd07a1e9c1..537412ad12a0 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -1038,6 +1038,55 @@ out_free_stack: goto out; } +static int ovl_get_lower_layers(struct ovl_fs *ufs, struct path *stack, + unsigned int numlower) +{ + int err; + unsigned int i; + + err = -ENOMEM; + ufs->lower_layers = kcalloc(numlower, sizeof(struct ovl_layer), + GFP_KERNEL); + if (ufs->lower_layers == NULL) + goto out; + 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; + } + + 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; + } + /* + * Make lower layers R/O. That way fchmod/fchown on lower file + * will fail instead of modifying lower fs. + */ + 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 */ + if (i == 0) + ufs->same_sb = mnt->mnt_sb; + else if (ufs->same_sb != mnt->mnt_sb) + ufs->same_sb = NULL; + } + err = 0; +out: + return err; +} + static int ovl_fill_super(struct super_block *sb, void *data, int silent) { struct path upperpath = { }; @@ -1103,44 +1152,9 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) goto out_put_workdir; } - err = -ENOMEM; - ufs->lower_layers = kcalloc(numlower, sizeof(struct ovl_layer), - GFP_KERNEL); - if (ufs->lower_layers == NULL) - 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; - } - /* - * Make lower layers R/O. That way fchmod/fchown on lower file - * will fail instead of modifying lower fs. - */ - 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 */ - if (i == 0) - ufs->same_sb = mnt->mnt_sb; - else if (ufs->same_sb != mnt->mnt_sb) - ufs->same_sb = NULL; - } + err = ovl_get_lower_layers(ufs, stack, numlower); + if (err) + goto out_put_lower_layers; /* If the upper fs is nonexistent, we mark overlayfs r/o too */ if (!ufs->upper_mnt) -- 2.39.5