diff options
Diffstat (limited to 'libstore')
| -rw-r--r-- | libstore/device.c | 26 |
1 files changed, 16 insertions, 10 deletions
diff --git a/libstore/device.c b/libstore/device.c index 5639157a..e002866d 100644 --- a/libstore/device.c +++ b/libstore/device.c @@ -189,29 +189,35 @@ error_t store_device_create (device_t device, int flags, struct store **store) { struct store_run run; - size_t sizes[DEV_GET_SIZE_COUNT], block_size = 0; - size_t sizes_len = DEV_GET_SIZE_COUNT; - error_t err = device_get_status (device, DEV_GET_SIZE, sizes, &sizes_len); + size_t block_size = 0; + size_t sizes[DEV_STATUS_MAX]; + size_t sizes_len = DEV_STATUS_MAX; + error_t err; - if (! err) + /* Some Mach devices do not implement device_get_status, but do not + return an error. To detect these devices we set the size of the + input buffer to something larger than DEV_GET_SIZE_COUNT. If the + size of the returned device status is not equal to + DEV_GET_SIZE_COUNT, we know that something is wrong. */ + err = device_get_status (device, DEV_GET_SIZE, sizes, &sizes_len); + if (! err && sizes_len == DEV_GET_SIZE_COUNT) { - if (sizes_len != DEV_GET_SIZE_COUNT) - err = EINVAL; - else + block_size = sizes[DEV_GET_SIZE_RECORD_SIZE]; + + if (block_size) { - block_size = sizes[DEV_GET_SIZE_RECORD_SIZE]; run.start = 0; run.length = sizes[DEV_GET_SIZE_DEVICE_SIZE] / block_size; if (run.length * block_size != sizes[DEV_GET_SIZE_DEVICE_SIZE]) /* Bogus results (which some mach devices return). */ - err = EINVAL; + block_size = 0; } } flags |= STORE_ENFORCED; /* 'cause it's the whole device. */ - if (err) + if (block_size == 0) /* Treat devices that can't do device_get_status as zero-length. */ return _store_device_create (device, flags, 0, &run, 0, store); else |