diff options
Diffstat (limited to 'src/basic')
| -rw-r--r-- | src/basic/btrfs-util.c | 39 | ||||
| -rw-r--r-- | src/basic/btrfs-util.h | 4 |
2 files changed, 33 insertions, 10 deletions
diff --git a/src/basic/btrfs-util.c b/src/basic/btrfs-util.c index 656bb13719..5f9e21dcba 100644 --- a/src/basic/btrfs-util.c +++ b/src/basic/btrfs-util.c @@ -20,6 +20,7 @@ #include <errno.h> #include <fcntl.h> #include <inttypes.h> +#include <linux/fs.h> #include <linux/loop.h> #include <stddef.h> #include <stdio.h> @@ -38,6 +39,7 @@ #include "alloc-util.h" #include "btrfs-ctree.h" #include "btrfs-util.h" +#include "chattr-util.h" #include "copy.h" #include "fd-util.h" #include "fileio.h" @@ -45,6 +47,7 @@ #include "macro.h" #include "missing.h" #include "path-util.h" +#include "rm-rf.h" #include "selinux-util.h" #include "smack-util.h" #include "sparse-endian.h" @@ -1718,28 +1721,46 @@ int btrfs_subvol_snapshot_fd(int old_fd, const char *new_path, BtrfsSnapshotFlag if (r < 0) return r; if (r == 0) { + bool plain_directory = false; + + /* If the source isn't a proper subvolume, fail unless fallback is requested */ if (!(flags & BTRFS_SNAPSHOT_FALLBACK_COPY)) return -EISDIR; r = btrfs_subvol_make(new_path); - if (r < 0) + if (r == -ENOTTY && (flags & BTRFS_SNAPSHOT_FALLBACK_DIRECTORY)) { + /* If the destination doesn't support subvolumes, then use a plain directory, if that's requested. */ + if (mkdir(new_path, 0755) < 0) + return r; + + plain_directory = true; + } else if (r < 0) return r; r = copy_directory_fd(old_fd, new_path, true); - if (r < 0) { - (void) btrfs_subvol_remove(new_path, BTRFS_REMOVE_QUOTA); - return r; - } + if (r < 0) + goto fallback_fail; if (flags & BTRFS_SNAPSHOT_READ_ONLY) { - r = btrfs_subvol_set_read_only(new_path, true); - if (r < 0) { - (void) btrfs_subvol_remove(new_path, BTRFS_REMOVE_QUOTA); - return r; + + if (plain_directory) { + /* Plain directories have no recursive read-only flag, but something pretty close to + * it: the IMMUTABLE bit. Let's use this here, if this is requested. */ + + if (flags & BTRFS_SNAPSHOT_FALLBACK_IMMUTABLE) + (void) chattr_path(new_path, FS_IMMUTABLE_FL, FS_IMMUTABLE_FL); + } else { + r = btrfs_subvol_set_read_only(new_path, true); + if (r < 0) + goto fallback_fail; } } return 0; + + fallback_fail: + (void) rm_rf(new_path, REMOVE_ROOT|REMOVE_PHYSICAL|REMOVE_SUBVOLUME); + return r; } r = extract_subvolume_name(new_path, &subvolume); diff --git a/src/basic/btrfs-util.h b/src/basic/btrfs-util.h index 1d852d502c..04a2e1274b 100644 --- a/src/basic/btrfs-util.h +++ b/src/basic/btrfs-util.h @@ -45,10 +45,12 @@ typedef struct BtrfsQuotaInfo { } BtrfsQuotaInfo; typedef enum BtrfsSnapshotFlags { - BTRFS_SNAPSHOT_FALLBACK_COPY = 1, + BTRFS_SNAPSHOT_FALLBACK_COPY = 1, /* If the source isn't a subvolume, reflink everything */ BTRFS_SNAPSHOT_READ_ONLY = 2, BTRFS_SNAPSHOT_RECURSIVE = 4, BTRFS_SNAPSHOT_QUOTA = 8, + BTRFS_SNAPSHOT_FALLBACK_DIRECTORY = 16, /* If the destination doesn't support subvolumes, reflink/copy instead */ + BTRFS_SNAPSHOT_FALLBACK_IMMUTABLE = 32, /* When we can't create a subvolume, use the FS_IMMUTABLE attribute for indicating read-only */ } BtrfsSnapshotFlags; typedef enum BtrfsRemoveFlags { |