From e20966be67676f34390decddbf5a863e85c34412 Mon Sep 17 00:00:00 2001
From: Christian Brauner <christian.brauner@ubuntu.com>
Date: Mon, 24 Jul 2017 16:32:10 +0200
Subject: [PATCH] dir: improvements

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
---
 src/lxc/bdev/lxcdir.c | 68 ++++++++++++++++++++++++++++---------------
 1 file changed, 44 insertions(+), 24 deletions(-)

diff --git a/src/lxc/bdev/lxcdir.c b/src/lxc/bdev/lxcdir.c
index 2e8e69f1e..610425aed 100644
--- a/src/lxc/bdev/lxcdir.c
+++ b/src/lxc/bdev/lxcdir.c
@@ -39,12 +39,12 @@ int dir_clonepaths(struct bdev *orig, struct bdev *new, const char *oldname,
 		   const char *cname, const char *oldpath, const char *lxcpath,
 		   int snap, uint64_t newsize, struct lxc_conf *conf)
 {
+	char *src_no_prefix;
 	int ret;
 	size_t len;
 
 	if (snap) {
-		ERROR("directories cannot be snapshotted.  Try aufs or "
-		      "overlayfs.");
+		ERROR("Directories cannot be snapshotted");
 		return -1;
 	}
 
@@ -53,17 +53,25 @@ int dir_clonepaths(struct bdev *orig, struct bdev *new, const char *oldname,
 
 	len = strlen(lxcpath) + strlen(cname) + strlen("rootfs") + 4 + 3;
 	new->src = malloc(len);
-	if (!new->src)
+	if (!new->src) {
+		ERROR("Failed to allocate memory");
 		return -1;
+	}
 
 	ret = snprintf(new->src, len, "dir:%s/%s/rootfs", lxcpath, cname);
-	if (ret < 0 || (size_t)ret >= len)
+	if (ret < 0 || (size_t)ret >= len) {
+		ERROR("Failed to create string");
 		return -1;
+	}
 
-	new->dest = strdup(new->src + 4);
-	if (!new->dest)
+	src_no_prefix = lxc_storage_get_path(new->src, new->type);
+	new->dest = strdup(src_no_prefix);
+	if (!new->dest) {
+		ERROR("Failed to duplicate string \"%s\"", new->src);
 		return -1;
+	}
 
+	TRACE("Created new path \"%s\" for dir storage driver", new->dest);
 	return 0;
 }
 
@@ -83,40 +91,45 @@ int dir_create(struct bdev *bdev, const char *dest, const char *n,
 
 	len += strlen(src) + 1;
 	bdev->src = malloc(len);
-	if (!bdev->src)
+	if (!bdev->src) {
+		ERROR("Failed to allocate memory");
 		return -1;
+	}
 
 	ret = snprintf(bdev->src, len, "dir:%s", src);
-	if (ret < 0 || (size_t)ret >= len)
+	if (ret < 0 || (size_t)ret >= len) {
+		ERROR("Failed to create string");
 		return -1;
+	}
 
 	bdev->dest = strdup(dest);
-	if (!bdev->dest)
-		return -1;
-
-	ret = mkdir_p(src, 0755);
-	if (ret < 0) {
-		ERROR("Failed to create %s", src);
+	if (!bdev->dest) {
+		ERROR("Failed to duplicate string \"%s\"", dest);
 		return -1;
 	}
 
-	ret = mkdir_p(bdev->dest, 0755);
+	ret = mkdir_p(dest, 0755);
 	if (ret < 0) {
-		ERROR("Failed to create %s", bdev->dest);
+		ERROR("Failed to create directory \"%s\"", dest);
 		return -1;
 	}
+	TRACE("Created directory \"%s\"", dest);
 
 	return 0;
 }
 
 int dir_destroy(struct bdev *orig)
 {
+	int ret;
 	char *src;
 
 	src = lxc_storage_get_path(orig->src, orig->src);
 
-	if (lxc_rmdir_onedev(src, NULL) < 0)
+	ret = lxc_rmdir_onedev(src, NULL);
+	if (ret < 0) {
+		ERROR("Failed to delete \"%s\"", src);
 		return -1;
+	}
 
 	return 0;
 }
@@ -134,10 +147,9 @@ int dir_detect(const char *path)
 
 int dir_mount(struct bdev *bdev)
 {
-	unsigned long mntflags;
-	char *src, *mntdata;
 	int ret;
-	unsigned long mflags;
+	unsigned long mflags, mntflags;
+	char *src, *mntdata;
 
 	if (strcmp(bdev->type, "dir"))
 		return -22;
@@ -145,7 +157,9 @@ int dir_mount(struct bdev *bdev)
 	if (!bdev->src || !bdev->dest)
 		return -22;
 
-	if (parse_mntopts(bdev->mntopts, &mntflags, &mntdata) < 0) {
+	ret = parse_mntopts(bdev->mntopts, &mntflags, &mntdata);
+	if (ret < 0) {
+		ERROR("Failed to parse mount options \"%s\"", bdev->mntopts);
 		free(mntdata);
 		return -22;
 	}
@@ -155,13 +169,19 @@ int dir_mount(struct bdev *bdev)
 	ret = mount(src, bdev->dest, "bind", MS_BIND | MS_REC | mntflags,
 		    mntdata);
 	if ((0 == ret) && (mntflags & MS_RDONLY)) {
-		DEBUG("remounting %s on %s with readonly options",
+		DEBUG("Remounting \"%s\" on \"%s\" readonly",
 		      src ? src : "(none)", bdev->dest ? bdev->dest : "(none)");
-		mflags = add_required_remount_flags(
-		    src, bdev->dest, MS_BIND | MS_REC | mntflags | MS_REMOUNT);
+		mflags = add_required_remount_flags(src, bdev->dest, MS_BIND | MS_REC | mntflags | MS_REMOUNT);
 		ret = mount(src, bdev->dest, "bind", mflags, mntdata);
 	}
 
+	if (ret < 0) {
+		SYSERROR("Failed to mount \"%s\" on \"%s\"", src, bdev->dest);
+		free(mntdata);
+		return -1;
+	}
+
+	TRACE("Mounted \"%s\" on \"%s\"", src, bdev->dest);
 	free(mntdata);
 	return ret;
 }
-- 
2.47.3