units: make networkd pull in its own .busname unit

[elogind.git] / src / shared / btrfs-util.c

diff --git a/src/shared/btrfs-util.c b/src/shared/btrfs-util.c
index ac1907daf7a42d256abc1bdfa26c393d4e3abc47..49528dbf0152e119d6ee1d9f3ed7acaa0f067b41 100644 (file)
--- a/src/shared/btrfs-util.c
+++ b/src/shared/btrfs-util.c
@@ -803,6 +803,7 @@ static int subvol_remove_children(int fd, const char *subvolume, uint64_t subvol
         struct btrfs_ioctl_vol_args vol_args = {};
         _cleanup_close_ int subvol_fd = -1;
         struct stat st;
+        bool made_writable = false;
         int r;
 
         assert(fd >= 0);
@@ -872,6 +873,14 @@ static int subvol_remove_children(int fd, const char *subvolume, uint64_t subvol
                         if (ioctl(fd, BTRFS_IOC_INO_LOOKUP, &ino_args) < 0)
                                 return -errno;
 
+                        if (!made_writable) {
+                                r = btrfs_subvol_set_read_only_fd(subvol_fd, false);
+                                if (r < 0)
+                                        return r;
+
+                                made_writable = true;
+                        }
+
                         if (isempty(ino_args.name))
                                 /* Subvolume is in the top-level
                                  * directory of the subvolume. */
@@ -948,6 +957,7 @@ static int subvol_snapshot_children(int old_fd, int new_fd, const char *subvolum
                 .fd = old_fd,
         };
         int r;
+        _cleanup_close_ int subvolume_fd = -1;
 
         assert(old_fd >= 0);
         assert(new_fd >= 0);
@@ -1028,14 +1038,47 @@ static int subvol_snapshot_children(int old_fd, int new_fd, const char *subvolum
                         if (new_child_fd < 0)
                                 return -errno;
 
+                        if (flags & BTRFS_SNAPSHOT_READ_ONLY) {
+                                /* If the snapshot is read-only we
+                                 * need to mark it writable
+                                 * temporarily, to put the subsnapshot
+                                 * into place. */
+
+                                if (subvolume_fd < 0) {
+                                        subvolume_fd = openat(new_fd, subvolume, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
+                                        if (subvolume_fd < 0)
+                                                return -errno;
+                                }
+
+                                r = btrfs_subvol_set_read_only_fd(subvolume_fd, false);
+                                if (r < 0)
+                                        return r;
+                        }
+
                         /* When btrfs clones the subvolumes, child
                          * subvolumes appear as directories. Remove
                          * them, so that we can create a new snapshot
                          * in their place */
-                        if (unlinkat(new_child_fd, p, AT_REMOVEDIR) < 0)
-                                return -errno;
+                        if (unlinkat(new_child_fd, p, AT_REMOVEDIR) < 0) {
+                                int k = -errno;
+
+                                if (flags & BTRFS_SNAPSHOT_READ_ONLY)
+                                        (void) btrfs_subvol_set_read_only_fd(subvolume_fd, true);
+
+                                return k;
+                        }
 
                         r = subvol_snapshot_children(old_child_fd, new_child_fd, p, sh->objectid, flags & ~BTRFS_SNAPSHOT_FALLBACK_COPY);
+
+                        /* Restore the readonly flag */
+                        if (flags & BTRFS_SNAPSHOT_READ_ONLY) {
+                                int k;
+
+                                k = btrfs_subvol_set_read_only_fd(subvolume_fd, true);
+                                if (r >= 0 && k < 0)
+                                        return k;
+                        }
+
                         if (r < 0)
                                 return r;
                 }