Attachment 583438 Details for Bug 820473 – patch for fixe the bug.

[patch] patch for fixe the bug.

0001-libparted-reenable-use-of-BLKPG-ioctls.patch (text/plain), 8.86 KB, created by Luan Jianhai on 2012-05-10 05:45:57 UTC

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Creator: Luan Jianhai

Created: 2012-05-10 05:45:57 UTC

Size: 8.86 KB

patch

obsolete

>From 0e04d17386274fc218a9e6f9ae17d75510e632a3 Mon Sep 17 00:00:00 2001
>From: Phillip Susi <psusi@cfl.rr.com>
>Date: Tue, 30 Mar 2010 15:04:43 -0400
>Subject: [PATCH] libparted: reenable use of BLKPG ioctls
>
>This patch effectively reverses commit 1d8f9bec which removed the code
>using the new BLKPG ioctls instead of the old BLKRRPART ioctl to update
>the in-kernel partition table.  The reason for this is because BLKRRPART
>fails if any partition on the disk is in use, but the BLKPG ioctls allow
>you to manipulate the other partitions on the disk without requiring a
>reboot.  Also BLKRRPART requires that the kernel understand the
>partition table on the disk, which may not always be the case.
>---
> libparted/arch/linux.c |  208 +++++++++++++++++++++++++++++++++++++++++++++++-
> 1 files changed, 205 insertions(+), 3 deletions(-)
>
>diff --git a/libparted/arch/linux.c b/libparted/arch/linux.c
>index d7ec2e4..65043d3 100644
>--- a/libparted/arch/linux.c
>+++ b/libparted/arch/linux.c
>@@ -19,7 +19,7 @@
> 
> #include <config.h>
> #include <arch/linux.h>
>-
>+#include <linux/blkpg.h>
> #include <parted/parted.h>
> #include <parted/debug.h>
> #if defined __s390__ || defined __s390x__
>@@ -2305,6 +2305,182 @@ linux_partition_is_busy (const PedPartition* part)
>         return 0;
> }
> 
>+static int
>+_blkpg_part_command (PedDevice* dev, struct blkpg_partition* part, int op)
>+{
>+        LinuxSpecific*          arch_specific = LINUX_SPECIFIC (dev);
>+        struct blkpg_ioctl_arg  ioctl_arg;
>+
>+        ioctl_arg.op = op;
>+        ioctl_arg.flags = 0;
>+        ioctl_arg.datalen = sizeof (struct blkpg_partition);
>+        ioctl_arg.data = (void*) part;
>+
>+        return ioctl (arch_specific->fd, BLKPG, &ioctl_arg) == 0;
>+}
>+
>+static int
>+_blkpg_add_partition (PedDisk* disk, const PedPartition *part)
>+{
>+        struct blkpg_partition  linux_part;
>+        const char*             vol_name;
>+        char*                   dev_name;
>+
>+        PED_ASSERT(disk != NULL, return 0);
>+        PED_ASSERT(disk->dev->sector_size % PED_SECTOR_SIZE_DEFAULT == 0,
>+                   return 0);
>+
>+        if (!_has_partitions (disk))
>+                return 0;
>+
>+        if (ped_disk_type_check_feature (disk->type,
>+                                         PED_DISK_TYPE_PARTITION_NAME))
>+                vol_name = ped_partition_get_name (part);
>+        else
>+                vol_name = NULL;
>+
>+        dev_name = _device_get_part_path (disk->dev, part->num);
>+        if (!dev_name)
>+                return 0;
>+
>+        memset (&linux_part, 0, sizeof (linux_part));
>+        linux_part.start = part->geom.start * disk->dev->sector_size;
>+        /* see fs/partitions/msdos.c:msdos_partition(): "leave room for LILO" */
>+        if (part->type & PED_PARTITION_EXTENDED)
>+                linux_part.length = part->geom.length == 1 ? 512 : 1024;
>+        else
>+                linux_part.length = part->geom.length * disk->dev->sector_size;
>+        linux_part.pno = part->num;
>+        strncpy (linux_part.devname, dev_name, BLKPG_DEVNAMELTH);
>+        if (vol_name)
>+                strncpy (linux_part.volname, vol_name, BLKPG_VOLNAMELTH);
>+
>+        free (dev_name);
>+
>+        if (!_blkpg_part_command (disk->dev, &linux_part,
>+                                  BLKPG_ADD_PARTITION)) {
>+                return ped_exception_throw (
>+                        PED_EXCEPTION_ERROR,
>+                        PED_EXCEPTION_IGNORE_CANCEL,
>+                        _("Error informing the kernel about modifications to "
>+                          "partition %s -- %s.  This means Linux won't know "
>+                          "about any changes you made to %s until you reboot "
>+                          "-- so you shouldn't mount it or use it in any way "
>+                          "before rebooting."),
>+                        linux_part.devname,
>+                        strerror (errno),
>+                        linux_part.devname)
>+                                == PED_EXCEPTION_IGNORE;
>+        }
>+
>+        return 1;
>+}
>+
>+static int
>+_blkpg_remove_partition (PedDisk* disk, int n)
>+{
>+        struct blkpg_partition  linux_part;
>+
>+        if (!_has_partitions (disk))
>+                return 0;
>+
>+        memset (&linux_part, 0, sizeof (linux_part));
>+        linux_part.pno = n;
>+        return _blkpg_part_command (disk->dev, &linux_part,
>+                                    BLKPG_DEL_PARTITION);
>+}
>+
>+/*
>+ * The number of partitions that a device can have depends on the kernel.
>+ * If we don't find this value in /sys/block/DEV/range, we will use our own
>+ * value.
>+ */
>+static unsigned int
>+_device_get_partition_range(PedDevice* dev)
>+{
>+        int         range, r;
>+        char        path[128];
>+        FILE*       fp;
>+        bool        ok;
>+
>+        r = snprintf(path, sizeof(path), "/sys/block/%s/range",
>+                     last_component(dev->path));
>+        if(r < 0 || r >= sizeof(path))
>+                return MAX_NUM_PARTS;
>+
>+        fp = fopen(path, "r");
>+        if(!fp)
>+                return MAX_NUM_PARTS;
>+
>+        ok = fscanf(fp, "%d", &range) == 1;
>+        fclose(fp);
>+
>+        /* (range <= 0) is none sense.*/
>+        return ok && range > 0 ? range : MAX_NUM_PARTS;
>+}
>+
>+/*
>+ * Sync the partition table in two step process:
>+ * 1. Remove all of the partitions from the kernel's tables, but do not attempt
>+ *    removal of any partition for which the corresponding ioctl call fails.
>+ * 2. Add all the partitions that we hold in disk.
>+ *
>+ * To achieve this two step process we must calculate the minimum number of
>+ * maximum possible partitions between what linux supports and what the label
>+ * type supports. EX:
>+ *
>+ * number=MIN(max_parts_supported_in_linux,max_parts_supported_in_msdos_tables)
>+ */
>+static int
>+_disk_sync_part_table (PedDisk* disk)
>+{
>+        PED_ASSERT(disk != NULL, return 0);
>+        PED_ASSERT(disk->dev != NULL, return 0);
>+        int lpn;
>+
>+        /* lpn = largest partition number. */
>+        if(ped_disk_get_max_supported_partition_count(disk, &lpn))
>+                lpn = PED_MIN(lpn, _device_get_partition_range(disk->dev));
>+        else
>+                lpn = _device_get_partition_range(disk->dev);
>+
>+        /* Its not possible to support largest_partnum < 0.
>+         * largest_partnum == 0 would mean does not support partitions.
>+         * */
>+        if(lpn < 0)
>+                return 0;
>+
>+        int *rets = ped_malloc(sizeof(int) * lpn);
>+        int *errnums = ped_malloc(sizeof(int) * lpn);
>+        int ret = 1;
>+        int i;
>+
>+        for (i = 1; i <= lpn; i++) {
>+                rets[i - 1] = _blkpg_remove_partition (disk, i);
>+                errnums[i - 1] = errno;
>+        }
>+
>+        for (i = 1; i <= lpn; i++) {
>+                const PedPartition *part = ped_disk_get_partition (disk, i);
>+                if (part) {
>+                        /* busy... so we won't (can't!) disturb ;)  Prolly
>+                         * doesn't matter anyway, because users shouldn't be
>+                         * changing mounted partitions anyway...
>+                         */
>+                        if (!rets[i - 1] && errnums[i - 1] == EBUSY)
>+                                        continue;
>+
>+                        /* add the (possibly modified or new) partition */
>+                        if (!_blkpg_add_partition (disk, part))
>+                                ret = 0;
>+                }
>+        }
>+
>+        free (rets);
>+        free (errnums);
>+        return ret;
>+}
>+
> #ifdef ENABLE_DEVICE_MAPPER
> static int
> _dm_remove_map_name(char *name)
>@@ -2543,16 +2719,42 @@ _kernel_reread_part_table (PedDevice* dev)
> }
> 
> static int
>+_have_blkpg ()
>+{
>+        static int have_blkpg = -1;
>+        int kver;
>+
>+        if (have_blkpg != -1)
>+                return have_blkpg;
>+
>+        kver = _get_linux_version();
>+        return have_blkpg = kver >= KERNEL_VERSION (2,4,0) ? 1 : 0;
>+}
>+
>+static int
> linux_disk_commit (PedDisk* disk)
> {
>-       if (!_has_partitions (disk))
>-               return 1;
>+        if (!_has_partitions (disk))
>+                return 1;
> 
> #ifdef ENABLE_DEVICE_MAPPER
>         if (disk->dev->type == PED_DEVICE_DM)
>                 return _dm_reread_part_table (disk);
> #endif
>         if (disk->dev->type != PED_DEVICE_FILE) {
>+                /* The ioctl() command BLKPG_ADD_PARTITION does not notify
>+                 * the devfs system; consequently, /proc/partitions will not
>+                 * be up to date, and the proper links in /dev are not
>+                 * created.  Therefore, if using DevFS, we must get the kernel
>+                 * to re-read and grok the partition table.
>+                 */
>+                /* Work around kernel dasd problem so we really do BLKRRPART */
>+                if (disk->dev->type != PED_DEVICE_DASD &&
>+                    _have_blkpg () ) {
>+                        if (_disk_sync_part_table (disk))
>+                                return 1;
>+                }
>+
>                 return _kernel_reread_part_table (disk->dev);
>         }
> 
>-- 
>1.7.6.5
>

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Attachments on bug 820473: 583438