Re: [Libguestfs] [PATCH 2/7] btrfs: Update btrfs_subvolume_list to take Mountable_or_Path

btrfs_subvolume_list can now take either the path of a mounted btrfs filesystem, or a mountable describing the location of a btrfs filesystem, or one of its volumes. In the latter case, the filesystem will be automatically mounted outside of /sysroot before running the btrfs tool, and unmounted afterwards. --- daemon/btrfs.c | 71 ++++++++++++++++++++++++++++++++++++++++++++-------- generator/actions.ml | 2 +- 2 files changed, 61 insertions(+), 12 deletions(-) diff --git a/daemon/btrfs.c b/daemon/btrfs.c index 81ce5f5..c3247ac 100644 --- a/daemon/btrfs.c +++ b/daemon/btrfs.c @@ -34,6 +34,7 @@ GUESTFSD_EXT_CMD(str_btrfs, btrfs); GUESTFSD_EXT_CMD(str_btrfstune, btrfstune); GUESTFSD_EXT_CMD(str_btrfsck, btrfsck); GUESTFSD_EXT_CMD(str_mkfs_btrfs, mkfs.btrfs); +GUESTFSD_EXT_CMD(str_umount, umount); int optgroup_btrfs_available (void) @@ -307,16 +308,47 @@ do_btrfs_subvolume_create (const char *dest) } guestfs_int_btrfssubvolume_list * -do_btrfs_subvolume_list (const char *fs) +do_btrfs_subvolume_list (const mountable_t *fs) { char **lines; /* Execute 'btrfs subvolume list <fs>', and split the output into lines */ { - CLEANUP_FREE char *fs_buf = sysroot_path (fs); - if (fs_buf == NULL) { - reply_with_perror ("malloc"); - return NULL; + CLEANUP_FREE char *fs_buf = NULL; + + if (fs->type == MOUNTABLE_PATH) { + fs_buf = sysroot_path (fs->device); + if (fs_buf == NULL) { + reply_with_perror ("malloc"); + + cmderror: + if (fs->type != MOUNTABLE_PATH && fs_buf) { + CLEANUP_FREE char *err = NULL; + if (command (NULL, &err, str_umount, fs_buf, NULL) == -1) + fprintf (stderr, "%s\n", err); + + if (rmdir (fs_buf) == -1 && errno != ENOENT) + fprintf (stderr, "rmdir: %m\n"); + } + return NULL; + } + } + + else { + fs_buf = strdup ("/tmp/btrfs.XXXXXX"); + if (fs_buf == NULL) { + reply_with_perror ("strdup"); + goto cmderror; + } + + if (mkdtemp (fs_buf) == NULL) { + reply_with_perror ("mkdtemp"); + goto cmderror; + } + + if (mount_vfs_nochroot ("", NULL, fs, fs_buf, "<internal>") == -1) { + goto cmderror; + } } size_t i = 0; @@ -328,16 +360,33 @@ do_btrfs_subvolume_list (const char *fs) ADD_ARG (argv, i, fs_buf); ADD_ARG (argv, i, NULL); - CLEANUP_FREE char *out = NULL, *err = NULL; - int r = commandv (&out, &err, argv); + CLEANUP_FREE char *out = NULL, *errout = NULL; + int r = commandv (&out, &errout, argv); + + if (fs->type != MOUNTABLE_PATH) { + CLEANUP_FREE char *err = NULL; + if (command (NULL, &err, str_umount, fs_buf, NULL) == -1) { + reply_with_error ("%s", err ? err : "malloc"); + goto cmderror; + } + + if (rmdir (fs_buf) == -1 && errno != ENOENT) { + reply_with_error ("rmdir: %m\n"); + goto cmderror; + } + } + if (r == -1) { - reply_with_error ("%s: %s", fs, err); - return NULL; + CLEANUP_FREE char *fs_desc = mountable_to_string (fs); + if (fs_desc == NULL) { + fprintf (stderr, "malloc: %m"); + } + reply_with_error ("%s: %s", fs_desc ? fs_desc : "malloc", errout); + goto cmderror; } lines = split_lines (out); - if (!lines) - return NULL; + if (!lines) return NULL; } /* Output is: diff --git a/generator/actions.ml b/generator/actions.ml index 6a42bca..f17cb6a 100644 --- a/generator/actions.ml +++ b/generator/actions.ml @@ -9519,7 +9519,7 @@ directory and the name of the snapshot, in the form C</path/to/dest/name>." }; { defaults with name = "btrfs_subvolume_list"; - style = RStructList ("subvolumes", "btrfssubvolume"), [Pathname "fs"], []; + style = RStructList ("subvolumes", "btrfssubvolume"), [Mountable_or_Path "fs"], []; proc_nr = Some 325; optional = Some "btrfs"; camel_name = "BTRFSSubvolumeList"; tests = [] (* tested in tests/btrfs *); -- 1.8.1.2