#include <linux/initrd.h>
#include <linux/async.h>
#include <linux/fs_struct.h>
+#include <linux/slab.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_fs_sb.h>
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;
__setup("ro", readonly);
__setup("rw", readwrite);
+#ifdef CONFIG_BLOCK
+/**
+ * match_dev_by_uuid - callback for finding a partition using its uuid
+ * @dev: device passed in by the caller
+ * @data: opaque pointer to a 36 byte char array with a UUID
+ *
+ * Returns 1 if the device matches, and 0 otherwise.
+ */
+static int match_dev_by_uuid(struct device *dev, void *data)
+{
+ u8 *uuid = data;
+ struct hd_struct *part = dev_to_part(dev);
+
+ if (!part->info)
+ goto no_match;
+
+ if (memcmp(uuid, part->info->uuid, sizeof(part->info->uuid)))
+ goto no_match;
+
+ return 1;
+no_match:
+ return 0;
+}
+
+
+/**
+ * devt_from_partuuid - looks up the dev_t of a partition by its 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)
+{
+ 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);
+
+ dev = class_find_device(&block_class, NULL, uuid, &match_dev_by_uuid);
+ if (!dev)
+ goto done;
+
+ res = dev->devt;
+
+ /* 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;
+}
+#endif
+
/*
* Convert a name into device number. We accept the following variants:
*
* of partition - device number of disk plus the partition number
* 5) /dev/<disk_name>p<decimal> - same as the above, that form is
* 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
dev_t res = 0;
int part;
+#ifdef CONFIG_BLOCK
+ if (strncmp(name, "PARTUUID=", 9) == 0) {
+ name += 9;
+ res = devt_from_partuuid(name);
+ if (!res)
+ goto fail;
+ goto done;
+ }
+#endif
+
if (strncmp(name, "/dev/", 5) != 0) {
unsigned maj, min;
goto done;
/*
- * try non-existant, but valid partition, which may only exist
+ * try non-existent, but valid partition, which may only exist
* after revalidating the disk, like partitioned md devices
*/
while (p > s && isdigit(p[-1]))
if (err)
return err;
- sys_chdir("/root");
+ sys_chdir((const char __user __force *)"/root");
ROOT_DEV = current->fs->pwd.mnt->mnt_sb->s_dev;
- printk("VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
+ printk(KERN_INFO
+ "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
current->fs->pwd.mnt->mnt_sb->s_type->name,
current->fs->pwd.mnt->mnt_sb->s_flags & MS_RDONLY ?
" readonly" : "", MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
}
#ifdef CONFIG_ROOT_NFS
+
+#define NFSROOT_TIMEOUT_MIN 5
+#define NFSROOT_TIMEOUT_MAX 30
+#define NFSROOT_RETRY_MAX 5
+
static int __init mount_nfs_root(void)
{
- void *data = nfs_root_data();
+ char *root_dev, *root_data;
+ unsigned int timeout;
+ int try, err;
- create_dev("/dev/root", ROOT_DEV);
- if (data &&
- do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
- return 1;
+ err = nfs_root_data(&root_dev, &root_data);
+ if (err != 0)
+ return 0;
+
+ /*
+ * The server or network may not be ready, so try several
+ * times. Stop after a few tries in case the client wants
+ * to fall back to other boot methods.
+ */
+ timeout = NFSROOT_TIMEOUT_MIN;
+ for (try = 1; ; try++) {
+ err = do_mount_root(root_dev, "nfs",
+ root_mountflags, root_data);
+ if (err == 0)
+ return 1;
+ if (try > NFSROOT_RETRY_MAX)
+ break;
+
+ /* Wait, in case the server refused us immediately */
+ ssleep(timeout);
+ timeout <<= 1;
+ if (timeout > NFSROOT_TIMEOUT_MAX)
+ timeout = NFSROOT_TIMEOUT_MAX;
+ }
return 0;
}
#endif
mount_root();
out:
+ devtmpfs_mount("dev");
sys_mount(".", "/", NULL, MS_MOVE, NULL);
- sys_chroot(".");
+ sys_chroot((const char __user __force *)".");
}
-
projects / linux-flexiantxendom0.git / blobdiff