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Add PARTUUID detection support

PATCH Superseded Nicholas Vinson 2 participants 12 messages Mar 18, 2018 – Mar 26, 2018

v6 of 10 Superseded Latest is v10 →

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Nicholas Vinson

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#0 lore raw

v6 cover Add PARTUUID detection support

Changes from Patch v5:
- Added sign-off by lines
- Fixed formatting errors found by Daniel Kiper

Changes from Patch v4:
- Updated grub.texi to reflect new behavior for GRUB_ENABLE_LINUX_PARTUUID

- Updated 10_linux.in logic to favor the PARTUUID when GRUB_ENABLE_LINUX_PARTUUID is enabled and GRUB_DISABLE_LINUX_UUID is disabled.

Changes from Patch v3:
- Removed flex-2.6.3 compatibility patch

- Removed Steve Kenton's patch

Changes from Patch v2:
- Added flex-2.6.3 compatibility patch

- Fixed a GPT partition read error

- Added Steve Kenton's patch

- Changed struct grub_part_gpt_type name to struct grub_part_gpt_part_guid

- Changed grub_part_gpt_type_t typedef name to grub_part_gpt_guid_t

- Added sprint_gpt_guid to Steve Kenton's patch

- Updated v1 and Steve Kenton's patch to use similar methods when reading partition GUIDs.

Changes from Patch v1:
- Added GRUB_ENABLE_LINUX_PARTUUID variable description to grub.texi

- Removed added gpt_part_guid copy logic from
grub_gpt_partition_map_iterate()

- Removed added NT disk signature copy logic from grub_partition_msdos_iterate()

- Removed modifications to partition number increment logic

- Removed added guid union definition.

- Added GRUB_ENABLE_LINUX_PARTUUID to grub-mkconfig.in export list

- Moved PRINT_GPT_PARTTYPE printing logic to print_gpt_guid() function in grub-probe.c

- Updated PRINT_GPT_PARTTYPE case to call print_gpt_guid() function in grub-probe.c.

- Created probe_partuuid() function in grub-probe.c

- Updated print == PRINT_PARTUUID check logic in probe() to call probe_partuuid().

- Updated UUID logic in 10_linux.in to enable root=PARTUUID feature only if GRUB_DISABLE_LINUX_UUID is not set to true, and GRUB_DEVICE_PARTUUID is not empty, GRUB_ENABLE_LINUX_PARTUUID is set to true.

Hello,

This is a request to add PARTUUID detection support grub-probe for MBR and GPT partition schemes. The Linux kernel supports mounting the root filesystem by Linux device name or by the Partition [GU]UID. GRUB's mkconfig, however, currently only supports specifying the rootfs in the kernel command-line by Linux device name unless an initramfs is also present. When an initramfs is present GRUB's mkconfig will set the kernel's root parameter value to either the Linux device name or to the filesystem [GU]UID.

Therefore, the only way to protect a Linux system from failing to boot when its Linux storage device names change is to either manually edit grub.cfg or /etc/default/grub and append root=PARTUUID=xxx to the command-line or create an initramfs that understands how to mount devices by filesystem [G]UID and let grub-mkconfig pass the filesystem [GU]UID to the initramfs.

The goal of this patch set is to enable root=PARTUUID=xxx support in grub-mkconfig, so that users don't have to manually edit /etc/default/grub or grub.cfg, or create an initramfs for the sole purpose of having a robust bootloader configuration for Linux.

Thanks,
Nicholas Vinson

Nicholas Vinson (4):
Centralize guid prints
Update grub_gpt_partentry
Add PARTUUID detection support to grub-probe
Update grub script template files

 docs/grub.texi               |  9 +++++
 grub-core/disk/ldm.c         |  2 +-
 grub-core/partmap/gpt.c      |  4 +--
 include/grub/gpt_partition.h |  8 ++---
 util/grub-install.c          |  2 +-
 util/grub-mkconfig.in        |  3 ++
 util/grub-probe.c            | 81 ++++++++++++++++++++++++++++++++++++--------
 util/grub.d/10_linux.in      | 12 +++++--
 8 files changed, 95 insertions(+), 26 deletions(-)
Signature · 1 line
2.16.2
author
#1 lore raw

PATCH v6 1/4 Centralize guid prints

Define print_gpt_guid(), so there is a central function for printing GUID strings. This change is a precursor for later patches which rely on this logic.

Signed-off-by Nicholas Vinson <[email protected]>
---
 util/grub-probe.c | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)
util/grub-probe.c +15 -15
index 8ac527d2f..21cb80fbe 100644
@@ -129,6 +129,20 @@ get_targets_string (void)
   return str;
 }
 
+static int
+print_gpt_guid (grub_gpt_part_guid_t guid)
+{
+  guid.data1 = grub_le_to_cpu32 (guid.data1);
+  guid.data2 = grub_le_to_cpu16 (guid.data2);
+  guid.data3 = grub_le_to_cpu16 (guid.data3);
+
+  return grub_printf ("%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
+		      guid.data1, guid.data2, guid.data3, guid.data4[0],
+		      guid.data4[1], guid.data4[2], guid.data4[3],
+		      guid.data4[4], guid.data4[5], guid.data4[6],
+		      guid.data4[7]);
+}
+
 static void
 do_print (const char *x, void *data)
 {

@@ -641,21 +655,7 @@ probe (const char *path, char **device_names, char delim)
 
               if (grub_disk_read (dev->disk, p->offset, p->index,
                                   sizeof (gptdata), &gptdata) == 0)
-                {
-                  grub_gpt_part_type_t gpttype;
-                  gpttype.data1 = grub_le_to_cpu32 (gptdata.type.data1);
-                  gpttype.data2 = grub_le_to_cpu16 (gptdata.type.data2);
-                  gpttype.data3 = grub_le_to_cpu16 (gptdata.type.data3);
-                  grub_memcpy (gpttype.data4, gptdata.type.data4, 8);
-
-                  grub_printf ("%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
-                               gpttype.data1, gpttype.data2,
-                               gpttype.data3, gpttype.data4[0], 
-                               gpttype.data4[1], gpttype.data4[2],
-                               gpttype.data4[3], gpttype.data4[4],
-                               gpttype.data4[5], gpttype.data4[6],
-                               gpttype.data4[7]);
-                }
+		print_gpt_guid(gptdata.type);
               dev->disk->partition = p;
             }
           putchar (delim);
Signature · 1 line
2.16.2
author
#3 lore raw

PATCH v6 2/4 Update grub_gpt_partentry

In reply to Nicholas Vinson

Rename grub_gpt_part_type to grub_gpt_part_guid and update grub_gpt_partentry to use this type for both the partition type GUID string and the partition GUID string entries. This change ensures that the two GUID fields are handled more consistently and helps to simplify the changes needed to add Linux partition GUID support.

Signed-off-by Nicholas Vinson <[email protected]>
---
 grub-core/disk/ldm.c         | 2 +-
 grub-core/partmap/gpt.c      | 4 ++--
 include/grub/gpt_partition.h | 8 ++++----
 util/grub-install.c          | 2 +-
 4 files changed, 8 insertions(+), 8 deletions(-)
grub-core/disk/ldm.c +1 -1
index 0f978ad05..2a22d2d6c 100644
@@ -135,7 +135,7 @@ msdos_has_ldm_partition (grub_disk_t dsk)
   return has_ldm;
 }
 
-static const grub_gpt_part_type_t ldm_type = GRUB_GPT_PARTITION_TYPE_LDM;
+static const grub_gpt_part_guid_t ldm_type = GRUB_GPT_PARTITION_TYPE_LDM;
 
 /* Helper for gpt_ldm_sector.  */
 static int
grub-core/partmap/gpt.c +2 -2
index 83bcba779..103f6796f 100644
@@ -33,10 +33,10 @@ static grub_uint8_t grub_gpt_magic[8] =
     0x45, 0x46, 0x49, 0x20, 0x50, 0x41, 0x52, 0x54
   };
 
-static const grub_gpt_part_type_t grub_gpt_partition_type_empty = GRUB_GPT_PARTITION_TYPE_EMPTY;
+static const grub_gpt_part_guid_t grub_gpt_partition_type_empty = GRUB_GPT_PARTITION_TYPE_EMPTY;
 
 #ifdef GRUB_UTIL
-static const grub_gpt_part_type_t grub_gpt_partition_type_bios_boot = GRUB_GPT_PARTITION_TYPE_BIOS_BOOT;
+static const grub_gpt_part_guid_t grub_gpt_partition_type_bios_boot = GRUB_GPT_PARTITION_TYPE_BIOS_BOOT;
 #endif
 
 /* 512 << 7 = 65536 byte sectors.  */
include/grub/gpt_partition.h +4 -4
index 1b32f6725..354fe2246 100644
@@ -22,14 +22,14 @@
 #include <grub/types.h>
 #include <grub/partition.h>
 
-struct grub_gpt_part_type
+struct grub_gpt_part_guid
 {
   grub_uint32_t data1;
   grub_uint16_t data2;
   grub_uint16_t data3;
   grub_uint8_t data4[8];
 } __attribute__ ((aligned(8)));
-typedef struct grub_gpt_part_type grub_gpt_part_type_t;
+typedef struct grub_gpt_part_guid grub_gpt_part_guid_t;
 
 #define GRUB_GPT_PARTITION_TYPE_EMPTY \
   { 0x0, 0x0, 0x0, \

@@ -70,8 +70,8 @@ struct grub_gpt_header
 
 struct grub_gpt_partentry
 {
-  grub_gpt_part_type_t type;
-  grub_uint8_t guid[16];
+  grub_gpt_part_guid_t type;
+  grub_gpt_part_guid_t guid;
   grub_uint64_t start;
   grub_uint64_t end;
   grub_uint64_t attrib;
util/grub-install.c +1 -1
index 690f180c5..78d0138cb 100644
@@ -714,7 +714,7 @@ is_prep_partition (grub_device_t dev)
       if (grub_disk_read (dev->disk, p->offset, p->index,
 			  sizeof (gptdata), &gptdata) == 0)
 	{
-	  const grub_gpt_part_type_t template = {
+	  const grub_gpt_part_guid_t template = {
 	    grub_cpu_to_le32_compile_time (0x9e1a2d38),
 	    grub_cpu_to_le16_compile_time (0xc612),
 	    grub_cpu_to_le16_compile_time (0x4316),
Signature · 1 line
2.16.2
author
#5 lore raw

PATCH v6 3/4 Add PARTUUID detection support to grub-probe

In reply to Nicholas Vinson

Add PARTUUID detection support grub-probe for MBR and GPT partition schemes.

Signed-off-by Nicholas Vinson <[email protected]>
---
 util/grub-probe.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
util/grub-probe.c +51 -0
index 21cb80fbe..0ae73c591 100644
@@ -28,6 +28,7 @@
 #include <grub/partition.h>
 #include <grub/msdos_partition.h>
 #include <grub/gpt_partition.h>
+#include <grub/i386/pc/boot.h>
 #include <grub/emu/hostdisk.h>
 #include <grub/emu/getroot.h>
 #include <grub/term.h>

@@ -62,6 +63,7 @@ enum {
   PRINT_DRIVE,
   PRINT_DEVICE,
   PRINT_PARTMAP,
+  PRINT_PARTUUID,
   PRINT_ABSTRACTION,
   PRINT_CRYPTODISK_UUID,
   PRINT_HINT_STR,

@@ -85,6 +87,7 @@ static const char *targets[] =
     [PRINT_DRIVE]              = "drive",
     [PRINT_DEVICE]             = "device",
     [PRINT_PARTMAP]            = "partmap",
+    [PRINT_PARTUUID]           = "partuuid",
     [PRINT_ABSTRACTION]        = "abstraction",
     [PRINT_CRYPTODISK_UUID]    = "cryptodisk_uuid",
     [PRINT_HINT_STR]           = "hints_string",

@@ -181,6 +184,48 @@ probe_partmap (grub_disk_t disk, char delim)
     }
 }
 
+static void
+probe_partuuid (grub_disk_t disk, char delim)
+{
+  /*
+   * Nested partitions not supported for now.
+   * Non-nested partitions must have disk->partition->parent == NULL
+   */
+  if (disk->partition && disk->partition->parent == NULL)
+    {
+      if (strcmp(disk->partition->partmap->name, "msdos") == 0)
+	{
+	    /*
+	     * The partition GUID for MSDOS is the partition number (starting
+	     * with 1) prepended with the NT disk signature.
+	     */
+            grub_uint32_t nt_disk_sig;
+	    grub_partition_t p = disk->partition;
+	    disk->partition = p->parent;
+
+	    if (grub_disk_read (disk, 0, GRUB_BOOT_MACHINE_WINDOWS_NT_MAGIC,
+				sizeof(nt_disk_sig), &nt_disk_sig) == 0)
+
+		grub_printf ("%08x-%02x",
+			     grub_le_to_cpu32(nt_disk_sig), 1 + p->number);
+	    disk->partition = p;
+	}
+      else if (strcmp(disk->partition->partmap->name, "gpt") == 0)
+	{
+	  grub_partition_t p = disk->partition;
+	  struct grub_gpt_partentry gptdata;
+
+	  disk->partition = p->parent;
+
+	  if (grub_disk_read (disk, p->offset, p->index,
+			      sizeof(gptdata), &gptdata) == 0)
+	    print_gpt_guid(gptdata.guid);
+
+	  disk->partition = p;
+	}
+    }
+}
+
 static void
 probe_cryptodisk_uuid (grub_disk_t disk, char delim)
 {

@@ -635,6 +680,12 @@ probe (const char *path, char **device_names, char delim)
 	/* Check if dev->disk itself is contained in a partmap.  */
 	probe_partmap (dev->disk, delim);
 
+      else if (print == PRINT_PARTUUID)
+	{
+	  probe_partuuid (dev->disk, delim);
+	  putchar (delim);
+	}
+
       else if (print == PRINT_MSDOS_PARTTYPE)
 	{
 	  if (dev->disk->partition
Signature · 1 line
2.16.2
author
#8 lore raw

PATCH v6 4/4 Update grub script template files

In reply to Nicholas Vinson

Update grub-mkconfig.in and 10_linux.in to support grub-probe's new partuuid target. Update grub.texi documenation.

Signed-off-by Nicholas Vinson <[email protected]>
---
 docs/grub.texi          |  9 +++++++++
 util/grub-mkconfig.in   |  3 +++
 util/grub.d/10_linux.in | 12 +++++++++---
 3 files changed, 21 insertions(+), 3 deletions(-)
docs/grub.texi +9 -0
index 65b4bbeda..b6a44eb6b 100644
@@ -1424,6 +1424,15 @@ the Linux kernel, using a @samp{root=UUID=...} kernel parameter.  This is
 usually more reliable, but in some cases it may not be appropriate.  To
 disable the use of UUIDs, set this option to @samp{true}.
 
+@item GRUB_ENABLE_LINUX_PARTUUID
+Setting this option to @samp{true} changes the behavior of
+@command{grub-mkconfig} so that it identifies the device containing the root
+filesystem by the partition UUID via the @samp{root=PARTUUID=...} kernel
+parameter.  This is desirable for Linux systems where identifying the root
+filesystem by its filesystem UUID or device name is imappropriate.  However,
+this option is only supported in Linux kernel versions least 2.6.37 (3.10 for
+systems using the MSDOS partition scheme) or newer.
+
 @item GRUB_DISABLE_RECOVERY
 If this option is set to @samp{true}, disable the generation of recovery
 mode menu entries.
util/grub-mkconfig.in +3 -0
index 35ef583b0..9a1f92bdf 100644
@@ -134,6 +134,7 @@ fi
 # Device containing our userland.  Typically used for root= parameter.
 GRUB_DEVICE="`${grub_probe} --target=device /`"
 GRUB_DEVICE_UUID="`${grub_probe} --device ${GRUB_DEVICE} --target=fs_uuid 2> /dev/null`" || true
+GRUB_DEVICE_PARTUUID="`${grub_probe} --device ${GRUB_DEVICE} --target=partuuid 2> /dev/null`" || true
 
 # Device containing our /boot partition.  Usually the same as GRUB_DEVICE.
 GRUB_DEVICE_BOOT="`${grub_probe} --target=device /boot`"

@@ -188,6 +189,7 @@ if [ "x${GRUB_ACTUAL_DEFAULT}" = "xsaved" ] ; then GRUB_ACTUAL_DEFAULT="`"${grub
 # override them.
 export GRUB_DEVICE \
   GRUB_DEVICE_UUID \
+  GRUB_DEVICE_PARTUUID \
   GRUB_DEVICE_BOOT \
   GRUB_DEVICE_BOOT_UUID \
   GRUB_FS \

@@ -223,6 +225,7 @@ export GRUB_DEFAULT \
   GRUB_TERMINAL_OUTPUT \
   GRUB_SERIAL_COMMAND \
   GRUB_DISABLE_LINUX_UUID \
+  GRUB_ENABLE_LINUX_PARTUUID \
   GRUB_DISABLE_RECOVERY \
   GRUB_VIDEO_BACKEND \
   GRUB_GFXMODE \
util/grub.d/10_linux.in +9 -3
index faedf74e1..53de33bea 100644
@@ -45,12 +45,18 @@ esac
 
 # btrfs may reside on multiple devices. We cannot pass them as value of root= parameter
 # and mounting btrfs requires user space scanning, so force UUID in this case.
-if [ "x${GRUB_DEVICE_UUID}" = "x" ] || [ "x${GRUB_DISABLE_LINUX_UUID}" = "xtrue" ] \
-    || ! test -e "/dev/disk/by-uuid/${GRUB_DEVICE_UUID}" \
+if [ "x${GRUB_DEVICE_UUID}" = "x" ] && [ "x${GRUB_DEVICE_PARTUUID}" = "x" ] \
+    || [ "x${GRUB_DISABLE_LINUX_UUID}" = "xtrue" ] \
+    || ( ! test -e "/dev/disk/by-uuid/${GRUB_DEVICE_UUID}" \
+        && ! test -e "/dev/disk/by-partuuid/${GRUB_DEVICE_PARTUUID}" ) \
     || ( test -e "${GRUB_DEVICE}" && uses_abstraction "${GRUB_DEVICE}" lvm ); then
   LINUX_ROOT_DEVICE=${GRUB_DEVICE}
-else
+elif [ "x${GRUB_ENABLE_LINUX_PARTUUID}" != "xtrue" ] \
+    || [ "x${GRUB_DEVICE_PARTUUID}" = "x" ] \
+    || ! test -e "/dev/disk/by-partuuid/${GRUB_DEVICE_PARTUUID}"; then
   LINUX_ROOT_DEVICE=UUID=${GRUB_DEVICE_UUID}
+else
+  LINUX_ROOT_DEVICE=PARTUUID=${GRUB_DEVICE_PARTUUID}
 fi
 
 case x"$GRUB_FS" in
Signature · 1 line
2.16.2
Reviewed-by on v6 2/4
#4 lore raw

Re: [GRUB PARTUUID PATCH V6 2/4] Update grub_gpt_partentry

In reply to Nicholas Vinson
Quoted 7 lines · Nicholas Vinson

Rename grub_gpt_part_type to grub_gpt_part_guid and update grub_gpt_partentry to use this type for both the partition type GUID string and the partition GUID string entries. This change ensures that the two GUID fields are handled more consistently and helps to simplify the changes needed to add Linux partition GUID support.

Signed-off-by Nicholas Vinson <[email protected]>
Reviewed-by Daniel Kiper <[email protected]>

Daniel

#6 lore raw

Re: [GRUB PARTUUID PATCH V6 3/4] Add PARTUUID detection support to grub-probe

In reply to Nicholas Vinson
Quoted 37 lines · Nicholas Vinson

Add PARTUUID detection support grub-probe for MBR and GPT partition schemes.

Signed-off-by Nicholas Vinson <[email protected]>
---
 util/grub-probe.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
util/grub-probe.c +3 -0
index 21cb80fbe..0ae73c591 100644
@@ -28,6 +28,7 @@
 #include <grub/partition.h>
 #include <grub/msdos_partition.h>
 #include <grub/gpt_partition.h>
+#include <grub/i386/pc/boot.h>
 #include <grub/emu/hostdisk.h>
 #include <grub/emu/getroot.h>
 #include <grub/term.h>

@@ -62,6 +63,7 @@ enum {
   PRINT_DRIVE,
   PRINT_DEVICE,
   PRINT_PARTMAP,
+  PRINT_PARTUUID,
   PRINT_ABSTRACTION,
   PRINT_CRYPTODISK_UUID,
   PRINT_HINT_STR,

@@ -85,6 +87,7 @@ static const char *targets[] =
     [PRINT_DRIVE]              = "drive",
     [PRINT_DEVICE]             = "device",
     [PRINT_PARTMAP]            = "partmap",
+    [PRINT_PARTUUID]           = "partuuid",
     [PRINT_ABSTRACTION]        = "abstraction",
     [PRINT_CRYPTODISK_UUID]    = "cryptodisk_uuid",
     [PRINT_HINT_STR]           = "hints_string",

util/grub-probe.c probe_partmap (grub_disk_t disk, char delim) · line 189

Quoted 6 lines
util/grub-probe.c +3 -0
@@ -181,6 +184,48 @@ probe_partmap (grub_disk_t disk, char delim)
     }
 }
 
+static void
+probe_partuuid (grub_disk_t disk, char delim)
+{

Define p here:
grub_partition_t p = disk->partition;

util/grub-probe.c probe_partmap (grub_disk_t disk, char delim) · line 202

Quoted 13 lines
util/grub-probe.c +13 -0
+  /*
+   * Nested partitions not supported for now.
+   * Non-nested partitions must have disk->partition->parent == NULL
+   */
+  if (disk->partition && disk->partition->parent == NULL)
+    {
+      if (strcmp(disk->partition->partmap->name, "msdos") == 0)
+	{
+	    /*
+	     * The partition GUID for MSDOS is the partition number (starting
+	     * with 1) prepended with the NT disk signature.
+	     */
+            grub_uint32_t nt_disk_sig;

Somthing is wrong with formating here and there. Please fix this.

util/grub-probe.c probe_partmap (grub_disk_t disk, char delim) · line 203

Quoted 1 line
util/grub-probe.c +1 -0
+	    grub_partition_t p = disk->partition;

Drop this...

util/grub-probe.c probe_partmap (grub_disk_t disk, char delim) · line 211

Quoted 8 lines
util/grub-probe.c +8 -0
+	    disk->partition = p->parent;
+
+	    if (grub_disk_read (disk, 0, GRUB_BOOT_MACHINE_WINDOWS_NT_MAGIC,
+				sizeof(nt_disk_sig), &nt_disk_sig) == 0)
+
+		grub_printf ("%08x-%02x",
+			     grub_le_to_cpu32(nt_disk_sig), 1 + p->number);
+	    disk->partition = p;

...and above line...

util/grub-probe.c probe_partmap (grub_disk_t disk, char delim) · line 224

Quoted 13 lines
util/grub-probe.c +13 -0
+	}
+      else if (strcmp(disk->partition->partmap->name, "gpt") == 0)
+	{
+	  grub_partition_t p = disk->partition;
+	  struct grub_gpt_partentry gptdata;
+
+	  disk->partition = p->parent;
+
+	  if (grub_disk_read (disk, p->offset, p->index,
+			      sizeof(gptdata), &gptdata) == 0)
+	    print_gpt_guid(gptdata.guid);
+
+	  disk->partition = p;

...and above line...

util/grub-probe.c probe_partmap (grub_disk_t disk, char delim) · line 225

Quoted 1 line
util/grub-probe.c +1 -0
+	}

...and add this here:

    disk->partition = p;

Daniel

#9 lore raw

Re: [GRUB PARTUUID PATCH V6 4/4] Update grub script template files

In reply to Nicholas Vinson
Quoted 15 lines · Nicholas Vinson

Update grub-mkconfig.in and 10_linux.in to support grub-probe's new partuuid target. Update grub.texi documenation.

Signed-off-by Nicholas Vinson <[email protected]>
---
 docs/grub.texi          |  9 +++++++++
 util/grub-mkconfig.in   |  3 +++
 util/grub.d/10_linux.in | 12 +++++++++---
 3 files changed, 21 insertions(+), 3 deletions(-)
docs/grub.texi +0 -0
index 65b4bbeda..b6a44eb6b 100644

docs/grub.texi the Linux kernel, using a @samp{root=UUID=...} kernel parameter. This is · line 1432

Quoted 9 lines
docs/grub.texi +6 -0
@@ -1424,6 +1424,15 @@ the Linux kernel, using a @samp{root=UUID=...} kernel parameter.  This is
 usually more reliable, but in some cases it may not be appropriate.  To
 disable the use of UUIDs, set this option to @samp{true}.
 
+@item GRUB_ENABLE_LINUX_PARTUUID
+Setting this option to @samp{true} changes the behavior of
+@command{grub-mkconfig} so that it identifies the device containing the root
+filesystem by the partition UUID via the @samp{root=PARTUUID=...} kernel
+parameter.  This is desirable for Linux systems where identifying the root
+filesystem by its filesystem UUID or device name is imappropriate.  However,

s/imappropriate/inappropriate/

docs/grub.texi the Linux kernel, using a @samp{root=UUID=...} kernel parameter. This is · line 1433

Quoted 1 line
docs/grub.texi +1 -0
+this option is only supported in Linux kernel versions least 2.6.37 (3.10 for

s/least/at least/?

Otherwise LGTM.

Daniel

author
#10 lore raw

Re: [GRUB PARTUUID PATCH V6 4/4] Update grub script template files

Quoted 19 lines · Daniel Kiper
Quoted 18 lines · Nicholas Vinson

Update grub-mkconfig.in and 10_linux.in to support grub-probe's new partuuid target. Update grub.texi documenation.

Signed-off-by Nicholas Vinson <[email protected]>
---
 docs/grub.texi          |  9 +++++++++
 util/grub-mkconfig.in   |  3 +++
 util/grub.d/10_linux.in | 12 +++++++++---
 3 files changed, 21 insertions(+), 3 deletions(-)
docs/grub.texi +0 -0
index 65b4bbeda..b6a44eb6b 100644
@@ -1424,6 +1424,15 @@ the Linux kernel, using a @samp{root=UUID=...} kernel parameter.  This is
 usually more reliable, but in some cases it may not be appropriate.  To
 disable the use of UUIDs, set this option to @samp{true}.
Quoted 8 lines

docs/grub.texi the Linux kernel, using a @samp{root=UUID=...} kernel parameter. This is · line 1432

Quoted 6 lines
docs/grub.texi +6 -0
+@item GRUB_ENABLE_LINUX_PARTUUID
+Setting this option to @samp{true} changes the behavior of
+@command{grub-mkconfig} so that it identifies the device containing the root
+filesystem by the partition UUID via the @samp{root=PARTUUID=...} kernel
+parameter.  This is desirable for Linux systems where identifying the root
+filesystem by its filesystem UUID or device name is imappropriate.  However,

s/imappropriate/inappropriate/

fixed

Quoted 4 lines

docs/grub.texi the Linux kernel, using a @samp{root=UUID=...} kernel parameter. This is · line 1433

Quoted 2 lines
docs/grub.texi +1 -0
+this option is only supported in Linux kernel versions least 2.6.37 (3.10 for

s/least/at least/?

I think s/least// would sound better than s/least/at least/. Thoughts?

Thanks,
Nicholas Vinson

Quoted 5 lines

Otherwise LGTM.

Daniel

author
#7 lore raw

Re: [GRUB PARTUUID PATCH V6 3/4] Add PARTUUID detection support to grub-probe

In reply to Daniel Kiper
Quoted 41 lines · Daniel Kiper
Quoted 40 lines · Nicholas Vinson

Add PARTUUID detection support grub-probe for MBR and GPT partition schemes.

Signed-off-by Nicholas Vinson <[email protected]>
---
 util/grub-probe.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
util/grub-probe.c +3 -0
index 21cb80fbe..0ae73c591 100644
@@ -28,6 +28,7 @@
 #include <grub/partition.h>
 #include <grub/msdos_partition.h>
 #include <grub/gpt_partition.h>
+#include <grub/i386/pc/boot.h>
 #include <grub/emu/hostdisk.h>
 #include <grub/emu/getroot.h>
 #include <grub/term.h>

@@ -62,6 +63,7 @@ enum {
   PRINT_DRIVE,
   PRINT_DEVICE,
   PRINT_PARTMAP,
+  PRINT_PARTUUID,
   PRINT_ABSTRACTION,
   PRINT_CRYPTODISK_UUID,
   PRINT_HINT_STR,

@@ -85,6 +87,7 @@ static const char *targets[] =
     [PRINT_DRIVE]              = "drive",
     [PRINT_DEVICE]             = "device",
     [PRINT_PARTMAP]            = "partmap",
+    [PRINT_PARTUUID]           = "partuuid",
     [PRINT_ABSTRACTION]        = "abstraction",
     [PRINT_CRYPTODISK_UUID]    = "cryptodisk_uuid",
     [PRINT_HINT_STR]           = "hints_string",

@@ -181,6 +184,48 @@ probe_partmap (grub_disk_t disk, char delim)
     }
 }
Quoted 6 lines

util/grub-probe.c probe_partmap (grub_disk_t disk, char delim) · line 189

Quoted 3 lines
util/grub-probe.c +3 -0
+static void
+probe_partuuid (grub_disk_t disk, char delim)
+{

Define p here:
grub_partition_t p = disk->partition;

done.

Quoted 16 lines
Quoted 4 lines
util/grub-probe.c +3 -0
+  /*
+   * Nested partitions not supported for now.
+   * Non-nested partitions must have disk->partition->parent == NULL

util/grub-probe.c probe_partmap (grub_disk_t disk, char delim) · line 202

Quoted 10 lines
util/grub-probe.c +10 -0
+   */
+  if (disk->partition && disk->partition->parent == NULL)
+    {
+      if (strcmp(disk->partition->partmap->name, "msdos") == 0)
+	{
+	    /*
+	     * The partition GUID for MSDOS is the partition number (starting
+	     * with 1) prepended with the NT disk signature.
+	     */
+            grub_uint32_t nt_disk_sig;

Somthing is wrong with formating here and there. Please fix this.

fixed. I forgot to tell vim not to expand tab characters.

Quoted 5 lines

util/grub-probe.c probe_partmap (grub_disk_t disk, char delim) · line 203

Quoted 2 lines
util/grub-probe.c +1 -0
+	    grub_partition_t p = disk->partition;

Drop this...

dropped.

Quoted 11 lines

util/grub-probe.c probe_partmap (grub_disk_t disk, char delim) · line 211

Quoted 8 lines
util/grub-probe.c +8 -0
+	    disk->partition = p->parent;
+
+	    if (grub_disk_read (disk, 0, GRUB_BOOT_MACHINE_WINDOWS_NT_MAGIC,
+				sizeof(nt_disk_sig), &nt_disk_sig) == 0)
+
+		grub_printf ("%08x-%02x",
+			     grub_le_to_cpu32(nt_disk_sig), 1 + p->number);
+	    disk->partition = p;

...and above line...

done.

Quoted 7 lines
Quoted 7 lines
util/grub-probe.c +7 -0
+	}
+      else if (strcmp(disk->partition->partmap->name, "gpt") == 0)
+	{
+	  grub_partition_t p = disk->partition;
+	  struct grub_gpt_partentry gptdata;
+
+	  disk->partition = p->parent;
Quoted 8 lines

util/grub-probe.c probe_partmap (grub_disk_t disk, char delim) · line 224

Quoted 6 lines
util/grub-probe.c +6 -0
+
+	  if (grub_disk_read (disk, p->offset, p->index,
+			      sizeof(gptdata), &gptdata) == 0)
+	    print_gpt_guid(gptdata.guid);
+
+	  disk->partition = p;

...and above line...

done.

Quoted 5 lines

util/grub-probe.c probe_partmap (grub_disk_t disk, char delim) · line 225

Quoted 2 lines
util/grub-probe.c +1 -0
+	}

...and add this here:

    disk->partition = p;

added.

Thanks,
Nicholas Vinson

Quoted 3 lines

Daniel

#11 lore raw

Re: [GRUB PARTUUID PATCH V6 4/4] Update grub script template files

In reply to Nick Vinson
Quoted 29 lines · Nick Vinson
Quoted 19 lines · Daniel Kiper
Quoted 18 lines · Nicholas Vinson

Update grub-mkconfig.in and 10_linux.in to support grub-probe's new partuuid target. Update grub.texi documenation.

Signed-off-by Nicholas Vinson <[email protected]>
---
 docs/grub.texi          |  9 +++++++++
 util/grub-mkconfig.in   |  3 +++
 util/grub.d/10_linux.in | 12 +++++++++---
 3 files changed, 21 insertions(+), 3 deletions(-)
docs/grub.texi +0 -0
index 65b4bbeda..b6a44eb6b 100644
@@ -1424,6 +1424,15 @@ the Linux kernel, using a @samp{root=UUID=...} kernel parameter.  This is
 usually more reliable, but in some cases it may not be appropriate.  To
 disable the use of UUIDs, set this option to @samp{true}.
Quoted 8 lines

docs/grub.texi the Linux kernel, using a @samp{root=UUID=...} kernel parameter. This is · line 1432

Quoted 6 lines
docs/grub.texi +6 -0
+@item GRUB_ENABLE_LINUX_PARTUUID
+Setting this option to @samp{true} changes the behavior of
+@command{grub-mkconfig} so that it identifies the device containing the root
+filesystem by the partition UUID via the @samp{root=PARTUUID=...} kernel
+parameter.  This is desirable for Linux systems where identifying the root
+filesystem by its filesystem UUID or device name is imappropriate.  However,

s/imappropriate/inappropriate/

Quoted 1 line

fixed

Could you repost whole patch series?

Daniel