[Libguestfs] Re: [PATCH] daemon: Fix btrfs volume device reverse-translation

Devices associated with btrfs volumes are not reverse-translated (e.g., btrfsvol:/dev/sdX to sdY). Forward translation occurs, creating a path mismatch. This causes errors in subsequent btrfs commands.

daemon/device-name-translation.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/daemon/device-name-translation.c b/daemon/device-name-translation.c index cfebc6495..eaf9a4686 100644 --- a/daemon/device-name-translation.c +++ b/daemon/device-name-translation.c @@ -251,9 +251,28 @@ device_name_translation (const char *device) char * reverse_device_name_translation (const char *device) { + const char *original_device = device; char *ret = NULL; size_t i; + const char *prefix = ""; + const char *suffix = ""; + bool btrfsvol = STRPREFIX (device, "btrfsvol:"); + if (btrfsvol) { + prefix = "btrfsvol:"; + + const char *device_start = device + strlen (prefix); + const char *device_end = strchr (device_start + strlen ("/dev/"), '/'); + device = strndup(device_start, device_end - device_start); + if (device == NULL) { + perror ("strndup"); + return NULL; + } + + suffix = device_end; + + } + /* Look it up in the cache, and if found return the canonical name. * If not found return a copy of the original string. */ @@ -265,13 +284,19 @@ reverse_device_name_translation (const char *device) char drv[16]; guestfs_int_drive_name (i, drv); - if (asprintf (&ret, "/dev/sd%s%s", drv, &device[len]) == -1) { + if (asprintf (&ret, "%s/dev/sd%s%s%s", prefix, drv, &device[len], suffix) == -1) { reply_with_perror ("asprintf"); + if (btrfsvol) + free (device); return NULL; } break; } } + if (btrfsvol) { + free (device); + device = original_device; + } if (ret == NULL) { ret = strdup (device); -- 2.52.0.460.gd25c4c69ec-goog