diff options
| -rw-r--r-- | init/do_mounts.c | 48 |
1 files changed, 43 insertions, 5 deletions
diff --git a/init/do_mounts.c b/init/do_mounts.c index c0851a8e030c..0f6e1d985a3b 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -28,7 +28,7 @@ int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */ int root_mountflags = MS_RDONLY | MS_SILENT; static char * __initdata root_device_name; static char __initdata saved_root_name[64]; -static int __initdata root_wait; +static int root_wait; dev_t ROOT_DEV; @@ -85,12 +85,15 @@ no_match: /** * devt_from_partuuid - looks up the dev_t of a partition by its UUID - * @uuid: 36 byte char array containing a hex ascii UUID + * @uuid: min 36 byte char array containing a hex ascii UUID * * The function will return the first partition which contains a matching * UUID value in its partition_meta_info struct. This does not search * by filesystem UUIDs. * + * If @uuid is followed by a "/PARTNROFF=%d", then the number will be + * extracted and used as an offset from the partition identified by the UUID. + * * Returns the matching dev_t on success or 0 on failure. */ static dev_t devt_from_partuuid(char *uuid_str) @@ -98,6 +101,28 @@ static dev_t devt_from_partuuid(char *uuid_str) dev_t res = 0; struct device *dev = NULL; u8 uuid[16]; + struct gendisk *disk; + struct hd_struct *part; + int offset = 0; + + if (strlen(uuid_str) < 36) + goto done; + + /* Check for optional partition number offset attributes. */ + if (uuid_str[36]) { + char c = 0; + /* Explicitly fail on poor PARTUUID syntax. */ + if (sscanf(&uuid_str[36], + "/PARTNROFF=%d%c", &offset, &c) != 1) { + printk(KERN_ERR "VFS: PARTUUID= is invalid.\n" + "Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n"); + if (root_wait) + printk(KERN_ERR + "Disabling rootwait; root= is invalid.\n"); + root_wait = 0; + goto done; + } + } /* Pack the requested UUID in the expected format. */ part_pack_uuid(uuid_str, uuid); @@ -107,8 +132,21 @@ static dev_t devt_from_partuuid(char *uuid_str) goto done; res = dev->devt; - put_device(dev); + /* Attempt to find the partition by offset. */ + if (!offset) + goto no_offset; + + res = 0; + disk = part_to_disk(dev_to_part(dev)); + part = disk_get_part(disk, dev_to_part(dev)->partno + offset); + if (part) { + res = part_devt(part); + put_device(part_to_dev(part)); + } + +no_offset: + put_device(dev); done: return res; } @@ -126,6 +164,8 @@ done: * used when disk name of partitioned disk ends on a digit. * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the * unique id of a partition if the partition table provides it. + * 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to + * a partition with a known unique id. * * If name doesn't have fall into the categories above, we return (0,0). * block_class is used to check if something is a disk name. If the disk @@ -143,8 +183,6 @@ dev_t name_to_dev_t(char *name) #ifdef CONFIG_BLOCK if (strncmp(name, "PARTUUID=", 9) == 0) { name += 9; - if (strlen(name) != 36) - goto fail; res = devt_from_partuuid(name); if (!res) goto fail; |