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Re: [PATCH] DM-RAID probing
|
From: |
Colin Watson |
|
Subject: |
Re: [PATCH] DM-RAID probing |
|
Date: |
Tue, 26 Jan 2010 14:32:01 +0000 |
|
User-agent: |
Mutt/1.5.18 (2008-05-17) |
On Mon, Jan 25, 2010 at 07:48:46PM +0000, Colin Watson wrote:
> I've pushed this branch with improved DM-RAID probing support:
>
> sftp://bzr.sv.gnu.org/srv/bzr/grub/branches/dmraid-probe/
>
> This makes it possible for things like this to work:
>
> grub-probe --target=partmap --device <DM-RAID partition device>
>
> ... which in turn makes it possible for grub-install to work when
> /boot/grub is on a DM-RAID device. The change is a bit involved, and
> requires the device-mapper userspace libraries to be effective (but I
> think these are pretty widespread). Could somebody have a look over
> this?
I've extended this so that device iteration sees DM-RAID disk devices as
well. This means that grub-mkdevicemap works (as long as you don't mind
DM-RAID disk devices showing up as "(hd2)" or similar; with UUIDs it
really doesn't matter much so I didn't go to the effort of inventing
some other namespace for them), which in turn will mean that my patch to
the Debian packaging to record the installation device using by-id paths
should work with no further changes required.
Please have a look. Proper error handling with the device-mapper
libraries winds up being a bit verbose, but I tried to make it as
readable as I could.
=== added file 'ChangeLog.dmraid-probe'
--- ChangeLog.dmraid-probe 1970-01-01 00:00:00 +0000
+++ ChangeLog.dmraid-probe 2010-01-26 14:26:09 +0000
@@ -0,0 +1,26 @@
+2010-01-26 Colin Watson <address@hidden>
+
+ * configure.ac: Check for Linux device-mapper support.
+
+ * util/hostdisk.c (device_is_mapped): New function.
+ (find_partition_start): New function, partly broken out from
+ linux_find_partition and grub_util_biosdisk_get_grub_dev but with
+ device-mapper support added.
+ (linux_find_partition): Use find_partition_start.
+ (convert_system_partition_to_system_disk): Add `st' argument.
+ Support Linux /dev/mapper/* devices if device-mapper support is
+ available; only DM-RAID devices are understood at present.
+ (find_system_device): Add `st' argument. Pass it to
+ convert_system_partition_to_system_disk.
+ (grub_util_biosdisk_get_grub_dev): Pass stat result to
+ find_system_device and convert_system_partition_to_system_disk. Use
+ find_partition_start.
+
+ * conf/common.rmk (grub_mkdevicemap_SOURCES): Add kern/env.c,
+ kern/err.c, kern/list.c, and kern/misc.c.
+ * util/deviceiter.c [__linux__]: Define MINOR.
+ (grub_util_iterate_devices): Add support for DM-RAID disk devices.
+ * util/mkdevicemap.c (grub_putchar): New function.
+ (grub_getkey): New function.
+ (grub_refresh): New function.
+ (main): Set debug=all if -v -v is used.
=== modified file 'conf/common.rmk'
--- conf/common.rmk 2010-01-20 20:31:39 +0000
+++ conf/common.rmk 2010-01-26 14:21:28 +0000
@@ -3,7 +3,8 @@
sbin_UTILITIES += grub-mkdevicemap
grub_mkdevicemap_SOURCES = gnulib/progname.c util/grub-mkdevicemap.c \
util/deviceiter.c \
- util/misc.c
+ util/misc.c \
+ kern/env.c kern/err.c kern/list.c kern/misc.c
ifeq ($(target_cpu)-$(platform), sparc64-ieee1275)
grub_mkdevicemap_SOURCES += util/ieee1275/ofpath.c util/ieee1275/devicemap.c
=== modified file 'configure.ac'
--- configure.ac 2010-01-25 09:06:55 +0000
+++ configure.ac 2010-01-25 16:40:40 +0000
@@ -659,6 +659,23 @@ AC_SUBST([enable_grub_mkfont])
AC_SUBST([freetype_cflags])
AC_SUBST([freetype_libs])
+AC_ARG_ENABLE([device-mapper],
+ [AS_HELP_STRING([--enable-device-mapper],
+ [enable Linux device-mapper support
(default=guessed)])])
+if test x"$enable_device_mapper" = xno ; then
+ device_mapper_excuse="explicitly disabled"
+fi
+
+if test x"$device_mapper_excuse" = x ; then
+ # Check for device-mapper library.
+ AC_CHECK_LIB([devmapper], [dm_task_create],
+ [LDFLAGS="$LDFLAGS -ldevmapper"
+ AC_DEFINE([HAVE_DEVICE_MAPPER], [1],
+ [Define to 1 if you have the devmapper library.])],
+ [device_mapper_excuse="need devmapper library"])
+ AC_SUBST([LIBDEVMAPPER])
+fi
+
AC_SUBST(ASFLAGS)
# Output files.
=== modified file 'util/deviceiter.c'
--- util/deviceiter.c 2009-07-29 14:11:50 +0000
+++ util/deviceiter.c 2010-01-26 14:22:50 +0000
@@ -31,6 +31,8 @@
#include <grub/util/misc.h>
#include <grub/util/deviceiter.h>
+#include <grub/list.h>
+#include <grub/misc.h>
#ifdef __linux__
# if !defined(__GLIBC__) || \
@@ -62,12 +64,23 @@ struct hd_geometry
| ((unsigned int) (__dev >> 32) & ~0xfff); \
})
# endif /* ! MAJOR */
+# ifndef MINOR
+# define MINOR(dev) \
+ ({ \
+ unsigned long long __dev = (dev); \
+ (unsigned) (__dev & 0xff) | ((unsigned int) (__dev >> 12) & ~0xff); \
+ })
+# endif /* ! MINOR */
# ifndef CDROM_GET_CAPABILITY
# define CDROM_GET_CAPABILITY 0x5331 /* get capabilities */
# endif /* ! CDROM_GET_CAPABILITY */
# ifndef BLKGETSIZE
# define BLKGETSIZE _IO(0x12,96) /* return device size */
# endif /* ! BLKGETSIZE */
+
+#ifdef HAVE_DEVICE_MAPPER
+# include <libdevmapper.h>
+#endif
#endif /* __linux__ */
/* Use __FreeBSD_kernel__ instead of __FreeBSD__ for compatibility with
@@ -411,6 +424,16 @@ check_device (const char *device)
return 1;
}
+#ifdef __linux__
+# ifdef HAVE_DEVICE_MAPPER
+struct dmraid_seen
+{
+ struct dmraid_seen *next;
+ const char *name;
+};
+# endif /* HAVE_DEVICE_MAPPER */
+#endif /* __linux__ */
+
void
grub_util_iterate_devices (int NESTED_FUNC_ATTR (*hook) (const char *, int),
int floppy_disks)
@@ -643,6 +666,123 @@ grub_util_iterate_devices (int NESTED_FU
return;
}
}
+
+# ifdef HAVE_DEVICE_MAPPER
+# define dmraid_check(cond, ...) \
+ if (! (cond)) \
+ { \
+ grub_dprintf ("deviceiter", __VA_ARGS__); \
+ goto dmraid_end; \
+ }
+
+ /* DM-RAID. */
+ {
+ struct dm_tree *tree = NULL;
+ struct dm_task *task = NULL;
+ struct dm_names *names = NULL;
+ unsigned int next = 0;
+ void *top_handle, *second_handle;
+ struct dm_tree_node *root, *top, *second;
+ struct dmraid_seen *seen = NULL;
+
+ /* Build DM tree for all devices. */
+ tree = dm_tree_create ();
+ dmraid_check (tree, "dm_tree_create failed\n");
+ task = dm_task_create (DM_DEVICE_LIST);
+ dmraid_check (task, "dm_task_create failed\n");
+ dmraid_check (dm_task_run (task), "dm_task_run failed\n");
+ names = dm_task_get_names (task);
+ dmraid_check (names, "dm_task_get_names failed\n");
+ dmraid_check (names->dev, "No DM devices found\n");
+ do
+ {
+ names = (void *) names + next;
+ dmraid_check (dm_tree_add_dev (tree, MAJOR (names->dev),
+ MINOR (names->dev)),
+ "dm_tree_add_dev (%s) failed\n", names->name);
+ next = names->next;
+ }
+ while (next);
+
+ /* Walk the second-level children of the inverted tree; that is, devices
+ which are directly composed of non-DM devices such as hard disks.
+ This class includes all DM-RAID disks and excludes all DM-RAID
+ partitions. */
+ root = dm_tree_find_node (tree, 0, 0);
+ top_handle = NULL;
+ top = dm_tree_next_child (&top_handle, root, 1);
+ while (top)
+ {
+ second_handle = NULL;
+ second = dm_tree_next_child (&second_handle, top, 1);
+ while (second)
+ {
+ const char *node_name, *node_uuid;
+ char *name;
+ struct dmraid_seen *seen_elt;
+
+ node_name = dm_tree_node_get_name (second);
+ dmraid_check (node_name, "dm_tree_node_get_name failed\n");
+ node_uuid = dm_tree_node_get_uuid (second);
+ dmraid_check (node_uuid, "dm_tree_node_get_uuid failed\n");
+ if (strncmp (node_uuid, "DMRAID-", 7) != 0)
+ {
+ grub_dprintf ("deviceiter", "%s is not DM-RAID\n", node_name);
+ goto dmraid_next_child;
+ }
+
+ /* Have we already seen this node? There are typically very few
+ DM-RAID disks, so a list should be fast enough. */
+ if (grub_named_list_find (GRUB_AS_NAMED_LIST (seen), node_name))
+ {
+ grub_dprintf ("deviceiter", "Already seen DM device %s\n",
+ node_name);
+ goto dmraid_next_child;
+ }
+
+ name = xasprintf ("/dev/mapper/%s", node_name);
+ if (check_device (name))
+ {
+ if (hook (name, 0))
+ {
+ free (name);
+ while (seen)
+ {
+ struct dmraid_seen *seen_elt =
+ grub_list_pop (GRUB_AS_LIST_P (&seen));
+ free (seen_elt);
+ }
+ if (task)
+ dm_task_destroy (task);
+ if (tree)
+ dm_tree_free (tree);
+ return;
+ }
+ }
+ free (name);
+
+ seen_elt = xmalloc (sizeof *seen_elt);
+ seen_elt->name = node_name;
+ grub_list_push (GRUB_AS_LIST_P (&seen), GRUB_AS_LIST (seen_elt));
+
+dmraid_next_child:
+ second = dm_tree_next_child (&second_handle, top, 1);
+ }
+ top = dm_tree_next_child (&top_handle, root, 1);
+ }
+
+dmraid_end:
+ while (seen)
+ {
+ struct dmraid_seen *seen_elt = grub_list_pop (GRUB_AS_LIST_P (&seen));
+ free (seen_elt);
+ }
+ if (task)
+ dm_task_destroy (task);
+ if (tree)
+ dm_tree_free (tree);
+ }
+# endif /* HAVE_DEVICE_MAPPER */
#endif /* __linux__ */
}
=== modified file 'util/grub-mkdevicemap.c'
--- util/grub-mkdevicemap.c 2010-01-16 00:26:52 +0000
+++ util/grub-mkdevicemap.c 2010-01-26 12:36:45 +0000
@@ -31,6 +31,7 @@
#include <grub/util/misc.h>
#include <grub/util/deviceiter.h>
+#include <grub/env.h>
#include <grub/i18n.h>
#define _GNU_SOURCE 1
@@ -38,6 +39,24 @@
#include "progname.h"
+void
+grub_putchar (int c)
+{
+ putchar (c);
+}
+
+int
+grub_getkey (void)
+{
+ return -1;
+}
+
+void
+grub_refresh (void)
+{
+ fflush (stdout);
+}
+
static void
make_device_map (const char *device_map, int floppy_disks)
{
@@ -158,6 +177,9 @@ main (int argc, char *argv[])
}
}
+ if (verbosity > 1)
+ grub_env_set ("debug", "all");
+
make_device_map (dev_map ? : DEFAULT_DEVICE_MAP, floppy_disks);
free (dev_map);
=== modified file 'util/hostdisk.c'
--- util/hostdisk.c 2010-01-25 17:04:22 +0000
+++ util/hostdisk.c 2010-01-25 17:39:37 +0000
@@ -97,6 +97,10 @@ struct hd_geometry
# include <sys/disk.h>
#endif
+#ifdef HAVE_DEVICE_MAPPER
+# include <libdevmapper.h>
+#endif
+
struct
{
char *drive;
@@ -253,6 +257,115 @@ grub_util_biosdisk_open (const char *nam
return GRUB_ERR_NONE;
}
+#ifdef HAVE_DEVICE_MAPPER
+static int
+device_is_mapped (const char *dev)
+{
+ struct stat st;
+
+ if (stat (dev, &st) < 0)
+ return 0;
+
+ return dm_is_dm_major (major (st.st_rdev));
+}
+#endif /* HAVE_DEVICE_MAPPER */
+
+#if defined(__linux__) || defined(__CYGWIN__)
+static grub_disk_addr_t
+find_partition_start (const char *dev)
+{
+ int fd;
+ struct hd_geometry hdg;
+
+#ifdef HAVE_DEVICE_MAPPER
+ if (device_is_mapped (dev)) {
+ struct dm_task *task = NULL;
+ grub_uint64_t start, length;
+ char *target_type, *params, *space;
+ grub_disk_addr_t partition_start;
+
+ /* If any device-mapper operation fails, we fall back silently to
+ HDIO_GETGEO. */
+ task = dm_task_create (DM_DEVICE_TABLE);
+ if (! task)
+ {
+ grub_dprintf ("hostdisk", "dm_task_create failed\n");
+ goto devmapper_fail;
+ }
+
+ if (! dm_task_set_name (task, dev))
+ {
+ grub_dprintf ("hostdisk", "dm_task_set_name failed\n");
+ goto devmapper_fail;
+ }
+
+ if (! dm_task_run (task))
+ {
+ grub_dprintf ("hostdisk", "dm_task_run failed\n");
+ goto devmapper_fail;
+ }
+
+ dm_get_next_target (task, NULL, &start, &length, &target_type, ¶ms);
+ if (! target_type)
+ {
+ grub_dprintf ("hostdisk", "no dm target\n");
+ goto devmapper_fail;
+ }
+ if (strcmp (target_type, "linear") != 0)
+ {
+ grub_dprintf ("hostdisk", "ignoring dm target %s (not linear)\n",
+ target_type);
+ goto devmapper_fail;
+ }
+ if (! params)
+ {
+ grub_dprintf ("hostdisk", "no dm params\n");
+ goto devmapper_fail;
+ }
+
+ /* The params string for a linear target looks like this:
+ DEVICE-NAME START-SECTOR
+ Parse this out. */
+ space = strchr (params, ' ');
+ if (! space)
+ goto devmapper_fail;
+ errno = 0;
+ partition_start = strtoull (space + 1, NULL, 10);
+ if (errno == 0)
+ {
+ grub_dprintf ("hostdisk", "dm %s starts at %llu\n",
+ dev, partition_start);
+ dm_task_destroy (task);
+ return partition_start;
+ }
+
+devmapper_fail:
+ if (task)
+ dm_task_destroy (task);
+ }
+#endif /* HAVE_DEVICE_MAPPER */
+
+ fd = open (dev, O_RDONLY);
+ if (fd == -1)
+ {
+ grub_error (GRUB_ERR_BAD_DEVICE, "cannot open `%s' while attempting to
get disk geometry", dev);
+ return 0;
+ }
+
+ if (ioctl (fd, HDIO_GETGEO, &hdg))
+ {
+ grub_error (GRUB_ERR_BAD_DEVICE,
+ "cannot get geometry of `%s'", dev);
+ close (fd);
+ return 0;
+ }
+
+ close (fd);
+
+ return hdg.start;
+}
+#endif /* __linux__ || __CYGWIN__ */
+
#ifdef __linux__
static int
linux_find_partition (char *dev, unsigned long sector)
@@ -284,22 +397,20 @@ linux_find_partition (char *dev, unsigne
for (i = 1; i < 10000; i++)
{
int fd;
- struct hd_geometry hdg;
+ grub_disk_addr_t start;
sprintf (p, format, i);
+
fd = open (real_dev, O_RDONLY);
if (fd == -1)
return 0;
-
- if (ioctl (fd, HDIO_GETGEO, &hdg))
- {
- close (fd);
- return 0;
- }
-
close (fd);
- if (hdg.start == sector)
+ start = find_partition_start (real_dev);
+ /* We don't care about errors here. */
+ grub_errno = GRUB_ERR_NONE;
+
+ if (start == sector)
{
strcpy (dev, real_dev);
return 1;
@@ -699,7 +810,7 @@ make_device_name (int drive, int dos_par
}
static char *
-convert_system_partition_to_system_disk (const char *os_dev)
+convert_system_partition_to_system_disk (const char *os_dev, struct stat *st)
{
#if defined(__linux__)
char *path = xmalloc (PATH_MAX);
@@ -817,6 +928,83 @@ convert_system_partition_to_system_disk
p[4] = '\0';
return path;
}
+
+#ifdef HAVE_DEVICE_MAPPER
+ /* If this is a DM-RAID device. */
+ if ((strncmp ("mapper/", p, 7) == 0))
+ {
+ static struct dm_tree *tree = NULL;
+ uint32_t maj, min;
+ struct dm_tree_node *node, *child;
+ void *handle;
+ const char *node_uuid, *child_uuid, *child_name;
+
+ if (! tree)
+ tree = dm_tree_create ();
+
+ if (! tree)
+ {
+ grub_dprintf ("hostdisk", "dm_tree_create failed\n");
+ return NULL;
+ }
+
+ maj = major (st->st_rdev);
+ min = minor (st->st_rdev);
+ if (! dm_tree_add_dev (tree, maj, min))
+ {
+ grub_dprintf ("hostdisk", "dm_tree_add_dev failed\n");
+ return NULL;
+ }
+
+ node = dm_tree_find_node (tree, maj, min);
+ if (! node)
+ {
+ grub_dprintf ("hostdisk", "dm_tree_find_node failed\n");
+ return NULL;
+ }
+ node_uuid = dm_tree_node_get_uuid (node);
+ if (! node_uuid)
+ {
+ grub_dprintf ("hostdisk", "%s has no DM uuid\n", path);
+ return NULL;
+ }
+ else if (strncmp (node_uuid, "DMRAID-", 7) != 0)
+ {
+ grub_dprintf ("hostdisk", "%s is not DM-RAID\n", path);
+ return NULL;
+ }
+
+ handle = NULL;
+ /* Counter-intuitively, device-mapper refers to the disk-like
+ device containing a DM-RAID partition device as a "child" of
+ the partition device. */
+ child = dm_tree_next_child (&handle, node, 0);
+ if (! child)
+ {
+ grub_dprintf ("hostdisk", "%s has no DM children\n", path);
+ return NULL;
+ }
+ child_uuid = dm_tree_node_get_uuid (child);
+ if (! child_uuid)
+ {
+ grub_dprintf ("hostdisk", "%s child has no DM uuid\n", path);
+ return NULL;
+ }
+ else if (strncmp (child_uuid, "DMRAID-", 7) != 0)
+ {
+ grub_dprintf ("hostdisk", "%s child is not DM-RAID\n", path);
+ return NULL;
+ }
+ child_name = dm_tree_node_get_name (child);
+ if (! child_name)
+ {
+ grub_dprintf ("hostdisk", "%s child has no DM name\n", path);
+ return NULL;
+ }
+
+ return xasprintf ("/dev/mapper/%s", child_name);
+ }
+#endif /* HAVE_DEVICE_MAPPER */
}
return path;
@@ -872,12 +1060,12 @@ device_is_wholedisk (const char *os_dev)
#endif
static int
-find_system_device (const char *os_dev)
+find_system_device (const char *os_dev, struct stat *st)
{
unsigned int i;
char *os_disk;
- os_disk = convert_system_partition_to_system_disk (os_dev);
+ os_disk = convert_system_partition_to_system_disk (os_dev, st);
if (! os_disk)
return -1;
@@ -911,7 +1099,7 @@ grub_util_biosdisk_get_grub_dev (const c
return 0;
}
- drive = find_system_device (os_dev);
+ drive = find_system_device (os_dev, &st);
if (drive < 0)
{
grub_error (GRUB_ERR_BAD_DEVICE,
@@ -919,8 +1107,8 @@ grub_util_biosdisk_get_grub_dev (const c
return 0;
}
- if (grub_strcmp (os_dev, convert_system_partition_to_system_disk (os_dev))
- == 0)
+ if (grub_strcmp (os_dev,
+ convert_system_partition_to_system_disk (os_dev, &st)) == 0)
return make_device_name (drive, -1, -1);
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__APPLE__)
@@ -942,8 +1130,7 @@ grub_util_biosdisk_get_grub_dev (const c
{
char *name;
grub_disk_t disk;
- int fd;
- struct hd_geometry hdg;
+ grub_disk_addr_t start;
int dos_part = -1;
int bsd_part = -1;
auto int find_partition (grub_disk_t disk,
@@ -973,7 +1160,7 @@ grub_util_biosdisk_get_grub_dev (const c
partition->index, partition->start);
}
- if (hdg.start == partition->start)
+ if (start == partition->start)
{
if (pcdata)
{
@@ -996,28 +1183,16 @@ grub_util_biosdisk_get_grub_dev (const c
if (MAJOR (st.st_rdev) == FLOPPY_MAJOR)
return name;
- fd = open (os_dev, O_RDONLY);
- if (fd == -1)
- {
- grub_error (GRUB_ERR_BAD_DEVICE, "cannot open `%s' while attempting to
get disk geometry", os_dev);
- free (name);
- return 0;
- }
-
- if (ioctl (fd, HDIO_GETGEO, &hdg))
+ start = find_partition_start (os_dev);
+ if (grub_errno != GRUB_ERR_NONE)
{
- grub_error (GRUB_ERR_BAD_DEVICE,
- "cannot get geometry of `%s'", os_dev);
- close (fd);
free (name);
return 0;
}
- close (fd);
-
- grub_util_info ("%s starts from %lu", os_dev, hdg.start);
+ grub_util_info ("%s starts from %lu", os_dev, start);
- if (hdg.start == 0 && device_is_wholedisk (os_dev))
+ if (start == 0 && device_is_wholedisk (os_dev))
return name;
grub_util_info ("opening the device %s", name);
Thanks,
--
Colin Watson address@hidden