btrfs: non-functional changes

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/bdev/lxcbtrfs.c b/src/lxc/bdev/lxcbtrfs.c
index 07265490774af8006611d84552ecdacba8491478..43cd686bfcd28efbf5061af4757ad2861ec2db08 100644 (file)
--- a/src/lxc/bdev/lxcbtrfs.c
+++ b/src/lxc/bdev/lxcbtrfs.c
@@ -225,38 +225,40 @@ int btrfs_umount(struct bdev *bdev)
 
 static int btrfs_subvolume_create(const char *path)
 {
-       int ret, fd = -1;
-       struct btrfs_ioctl_vol_args  args;
-       char *p, *newfull = strdup(path);
+       int ret, saved_errno;
+       struct btrfs_ioctl_vol_args args;
+       char *p, *newfull;
+       int fd = -1;
 
+       newfull = strdup(path);
        if (!newfull) {
-               ERROR("Error: out of memory");
-               return -1;
+               errno = ENOMEM;
+               return -ENOMEM;
        }
 
        p = strrchr(newfull, '/');
        if (!p) {
-               ERROR("bad path: %s", path);
                free(newfull);
-               return -1;
+               errno = EINVAL;
+               return -EINVAL;
        }
        *p = '\0';
 
        fd = open(newfull, O_RDONLY);
+       free(newfull);
        if (fd < 0) {
-               ERROR("Error opening %s", newfull);
-               free(newfull);
-               return -1;
+               return -errno;
        }
 
        memset(&args, 0, sizeof(args));
-       strncpy(args.name, p+1, BTRFS_SUBVOL_NAME_MAX);
-       args.name[BTRFS_SUBVOL_NAME_MAX-1] = 0;
+       strncpy(args.name, p + 1, BTRFS_SUBVOL_NAME_MAX);
+       args.name[BTRFS_SUBVOL_NAME_MAX - 1] = 0;
+
        ret = ioctl(fd, BTRFS_IOC_SUBVOL_CREATE, &args);
-       INFO("btrfs: snapshot create ioctl returned %d", ret);
+       saved_errno = errno;
 
-       free(newfull);
        close(fd);
+       errno = saved_errno;
        return ret;
 }
 
@@ -303,39 +305,37 @@ out:
 
 int btrfs_snapshot(const char *orig, const char *new)
 {
+       struct btrfs_ioctl_vol_args_v2 args;
+       char *newdir, *newname;
+       char *newfull = NULL;
+       int saved_errno = -1;
        int fd = -1, fddst = -1, ret = -1;
-       struct btrfs_ioctl_vol_args_v2  args;
-       char *newdir, *newname, *newfull = NULL;
 
        newfull = strdup(new);
-       if (!newfull) {
-               ERROR("Error: out of memory");
+       if (!newfull)
                goto out;
-       }
-       // make sure the directory doesn't already exist
-       if (rmdir(newfull) < 0 && errno != ENOENT) {
-               SYSERROR("Error removing empty new rootfs");
+
+       ret = rmdir(newfull);
+       if (ret < 0 && errno != ENOENT)
                goto out;
-       }
+
        newname = basename(newfull);
-       newdir = dirname(newfull);
        fd = open(orig, O_RDONLY);
-       if (fd < 0) {
-               SYSERROR("Error opening original rootfs %s", orig);
+       if (fd < 0)
                goto out;
-       }
+
+       newdir = dirname(newfull);
        fddst = open(newdir, O_RDONLY);
-       if (fddst < 0) {
-               SYSERROR("Error opening new container dir %s", newdir);
+       if (fddst < 0)
                goto out;
-       }
 
        memset(&args, 0, sizeof(args));
        args.fd = fd;
        strncpy(args.name, newname, BTRFS_SUBVOL_NAME_MAX);
-       args.name[BTRFS_SUBVOL_NAME_MAX-1] = 0;
+       args.name[BTRFS_SUBVOL_NAME_MAX - 1] = 0;
+
        ret = ioctl(fddst, BTRFS_IOC_SNAP_CREATE_V2, &args);
-       INFO("btrfs: snapshot create ioctl returned %d", ret);
+       saved_errno = errno;
 
 out:
        if (fddst != -1)
@@ -343,6 +343,9 @@ out:
        if (fd != -1)
                close(fd);
        free(newfull);
+
+       if (saved_errno >= 0)
+               errno = saved_errno;
        return ret;
 }
 
@@ -357,13 +360,13 @@ static int btrfs_snapshot_wrapper(void *data)
        }
        if (setgroups(0, NULL) < 0)
                WARN("Failed to clear groups");
+
        if (setuid(0) < 0) {
                ERROR("Failed to setuid to 0");
                return -1;
        }
 
        src = lxc_storage_get_path(arg->src, "btrfs");
-
        return btrfs_snapshot(src, arg->dest);
 }
 
@@ -372,6 +375,7 @@ int btrfs_clonepaths(struct bdev *orig, struct bdev *new, const char *oldname,
                     const char *lxcpath, int snap, uint64_t newsize,
                     struct lxc_conf *conf)
 {
+       int ret;
        char *src;
 
        if (!orig->dest || !orig->src)
@@ -388,16 +392,27 @@ int btrfs_clonepaths(struct bdev *orig, struct bdev *new, const char *oldname,
            (const char *[]){"btrfs:", *lxcpath != '/' ? lxcpath : ++lxcpath,
                             cname, "rootfs", NULL},
            false);
-       if (!new->src)
+       if (!new->src) {
+               ERROR("Failed to create new rootfs path");
                return -1;
+       }
+       TRACE("Created new rootfs path \"%s\"", new->src);
 
        src = lxc_storage_get_path(new->src, "btrfs");
        new->dest = strdup(src);
-       if (!new->dest)
+       if (!new->dest) {
+               ERROR("Failed to duplicate string \"%s\"", src);
                return -1;
+       }
 
-       if (orig->mntopts && (new->mntopts = strdup(orig->mntopts)) == NULL)
-               return -1;
+       if (orig->mntopts) {
+               new->mntopts = strdup(orig->mntopts);
+               if (!new->mntopts) {
+                       ERROR("Failed to duplicate string \"%s\"",
+                             orig->mntopts);
+                       return -1;
+               }
+       }
 
        if (snap) {
                struct rsync_data_char sdata;
@@ -409,12 +424,16 @@ int btrfs_clonepaths(struct bdev *orig, struct bdev *new, const char *oldname,
                                     "btrfs_snapshot_wrapper");
        }
 
-       if (rmdir(new->dest) < 0 && errno != ENOENT) {
-               SYSERROR("removing %s", new->dest);
+       ret = rmdir(new->dest);
+       if (ret < 0 && errno != ENOENT) {
+               SYSERROR("Failed to remove directory \"%s\"", new->dest);
                return -1;
        }
 
-       return btrfs_subvolume_create(new->dest);
+       ret = btrfs_subvolume_create(new->dest);
+       if (ret < 0)
+               SYSERROR("Failed to create btrfs subvolume \"%s\"", new->dest);
+       return ret;
 }
 
 static int btrfs_do_destroy_subvol(const char *path)