[parted-devel] [PATCH] Properly sync partitions with operating system

Joel Granados Moreno jgranado at redhat.com
Wed Feb 18 21:01:11 UTC 2009


---
 include/parted/disk.h   |    3 +-
 libparted/arch/linux.c  |  113 +++++++++++++++++++++++++++++++++-------------
 libparted/disk.c        |   14 +++++-
 libparted/labels/aix.c  |    8 +++
 libparted/labels/bsd.c  |    2 +
 libparted/labels/dasd.c |    1 +
 libparted/labels/dos.c  |   10 ++++-
 libparted/labels/dvh.c  |    3 +-
 libparted/labels/gpt.c  |    9 +++-
 libparted/labels/loop.c |    2 +
 libparted/labels/mac.c  |   10 ++++-
 libparted/labels/pc98.c |    2 +
 libparted/labels/rdb.c  |    2 +
 libparted/labels/sun.c  |    2 +
 14 files changed, 143 insertions(+), 38 deletions(-)

diff --git a/include/parted/disk.h b/include/parted/disk.h
index dfcf39e..9e50716 100644
--- a/include/parted/disk.h
+++ b/include/parted/disk.h
@@ -210,6 +210,7 @@ struct _PedDiskOps {
         /* other */
         int (*alloc_metadata) (PedDisk* disk);
         int (*get_max_primary_partition_count) (const PedDisk* disk);
+        int (*get_max_partition_count) (const PedDisk* disk);
 };
 
 struct _PedDiskType {
@@ -322,7 +323,7 @@ extern PedPartition* ped_disk_extended_partition (const PedDisk* disk);
 /* internal functions */
 extern PedDisk* _ped_disk_alloc (const PedDevice* dev, const PedDiskType* type);
 extern void _ped_disk_free (PedDisk* disk);
-
+extern int ped_disk_get_max_partition_num(const PedDisk* disk);
 
 /** @} */
 
diff --git a/libparted/arch/linux.c b/libparted/arch/linux.c
index 4a8c9e7..35ef1a5 100644
--- a/libparted/arch/linux.c
+++ b/libparted/arch/linux.c
@@ -279,6 +279,9 @@ struct blkdev_ioctl_param {
                 || (M) == SCSI_CDROM_MAJOR                              \
                 || ((M) >= SCSI_DISK1_MAJOR && (M) <= SCSI_DISK7_MAJOR))
 
+/* Maximum number of partitions supported by linux. */
+#define MAX_NUM_PARTS		16
+
 static char* _device_get_part_path (PedDevice* dev, int num);
 static int _partition_is_mounted_by_path (const char* path);
 
@@ -2261,45 +2264,91 @@ _blkpg_remove_partition (PedDisk* disk, int n)
                                     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 int
+_device_get_partition_range(PedDevice* dev)
+{
+	int		range;
+	char	path[512];
+	FILE*	fd;
+
+	if(snprintf(path, sizeof(path), "/sys/block/%s/range", dev->path) < 0)
+		return MAX_NUM_PARTS;
+
+	fd = fopen(path, "r");
+	if(!fd)
+		return MAX_NUM_PARTS;
+
+	if(fscanf(fd, "%d", range) == EOF)
+		return MAX_NUM_PARTS;
+
+	return range;
+}
+
+/*
+ * We sync the partition table in two step process:
+ * 1. We remove all the partitions from the kernel's tables.  The partitions
+ *    will not be removed if the ioctl call fails.
+ * 2. We 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)
+ *
+ * For now we will hard code the maximum number of partitions for linux to 16.
+ * Might want to search for a way to include this from somewhere.
+ */
 static int
 _disk_sync_part_table (PedDisk* disk)
 {
-        int largest_partnum = ped_disk_get_last_partition_num (disk);
-        if (largest_partnum <= 0)
-          return 1;
+	PED_ASSERT(disk != NULL, return 0);
+	PED_ASSERT(disk->dev != NULL, return 0);
 
-        int     last = 16;
-        int*    rets = ped_malloc(sizeof(int) * last);
-        int*    errnums = ped_malloc(sizeof(int) * last);
-        int     ret = 1;
-        int     i;
+	/* lpn = largest partition number. */
+	int lpn = PED_MIN(_device_get_partition_range(disk->dev),
+				ped_disk_get_max_partition_num(disk));
 
-        for (i = 1; i <= last; i++) {
-                rets[i - 1] = _blkpg_remove_partition (disk, i);
-                errnums[i - 1] = errno;
-        }
+	/* Its not possible to support largets_partnum <= 0. */
+	if(lpn <= 0)
+		return 0;
 
-        for (i = 1; i <= last; i++) {
-                const PedPartition *part;
+	int*	rets = ped_malloc(sizeof(int) * lpn);
+	int*	errnums = ped_malloc(sizeof(int) * lpn);
+	int		ret = 1;
+	int		i;
 
-                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;
-                }
-        }
+	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;
+
+		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;
+	free (rets);
+	free (errnums);
+	return ret;
 }
 
 #ifdef ENABLE_DEVICE_MAPPER
diff --git a/libparted/disk.c b/libparted/disk.c
index 93929b2..f259a9a 100644
--- a/libparted/disk.c
+++ b/libparted/disk.c
@@ -628,7 +628,7 @@ ped_disk_get_primary_partition_count (const PedDisk* disk)
 }
 
 /**
- * Get the highest partition number on \p disk.
+ * Get the highest available partition number on \p disk.
  */
 int
 ped_disk_get_last_partition_num (const PedDisk* disk)
@@ -648,6 +648,18 @@ ped_disk_get_last_partition_num (const PedDisk* disk)
 }
 
 /**
+ * Get the highest suppoerted partition number on \p disk.
+ */
+int
+ped_disk_get_max_partition_num(const PedDisk* disk)
+{
+	PED_ASSERT(disk != NULL, return 0);
+	PED_ASSERT(disk->type->ops->get_max_partition_count != NULL, return 0);
+
+	return disk->type->ops->get_max_partition_count(disk);
+}
+
+/**
  * Get the maximum number of (primary) partitions the disk label supports.
  * 
  * For example, MacIntosh partition maps can have different sizes,
diff --git a/libparted/labels/aix.c b/libparted/labels/aix.c
index b3dd176..c5da1fd 100644
--- a/libparted/labels/aix.c
+++ b/libparted/labels/aix.c
@@ -222,6 +222,12 @@ aix_get_max_primary_partition_count (const PedDisk* disk)
 }
 
 static int
+aix_get_max_partitoin_count (const PedDisk* disk)
+{
+	return 16;
+}
+
+static int
 aix_partition_align (PedPartition* part, const PedConstraint* constraint)
 {
         PED_ASSERT (part != NULL, return 0);
@@ -270,6 +276,8 @@ static PedDiskOps aix_disk_ops = {
 	alloc_metadata:		aix_alloc_metadata,
 	get_max_primary_partition_count:
 				aix_get_max_primary_partition_count,
+	get_max_partition_count:
+				aix_get_max_partitoin_count,
 
 	partition_set_name:		NULL,
 	partition_get_name:		NULL,
diff --git a/libparted/labels/bsd.c b/libparted/labels/bsd.c
index 3eb5363..a1c75b8 100644
--- a/libparted/labels/bsd.c
+++ b/libparted/labels/bsd.c
@@ -656,6 +656,8 @@ static PedDiskOps bsd_disk_ops = {
 
 	alloc_metadata:		bsd_alloc_metadata,
 	get_max_primary_partition_count:
+				bsd_get_max_primary_partition_count,
+	get_max_partition_count:
 				bsd_get_max_primary_partition_count
 };
 
diff --git a/libparted/labels/dasd.c b/libparted/labels/dasd.c
index 9edab40..af35707 100644
--- a/libparted/labels/dasd.c
+++ b/libparted/labels/dasd.c
@@ -128,6 +128,7 @@ static PedDiskOps dasd_disk_ops = {
 
 	alloc_metadata: dasd_alloc_metadata,
 	get_max_primary_partition_count: dasd_get_max_primary_partition_count,
+	get_max_partition_count: dasd_get_max_primary_partition_count,
 
 	partition_duplicate: NULL
 };
diff --git a/libparted/labels/dos.c b/libparted/labels/dos.c
index cb7e45e..3193069 100644
--- a/libparted/labels/dos.c
+++ b/libparted/labels/dos.c
@@ -2213,6 +2213,12 @@ msdos_get_max_primary_partition_count (const PedDisk* disk)
 	return 4;
 }
 
+static int
+msdos_get_max_partition_count(const PedDisk* disk)
+{
+	return 16;
+}
+
 static PedDiskOps msdos_disk_ops = {
 	probe:			msdos_probe,
 #ifndef DISCOVER_ONLY
@@ -2244,7 +2250,9 @@ static PedDiskOps msdos_disk_ops = {
 
 	alloc_metadata:		msdos_alloc_metadata,
 	get_max_primary_partition_count:
-				msdos_get_max_primary_partition_count
+				msdos_get_max_primary_partition_count,
+	get_max_partition_count:
+				msdos_get_max_partition_count
 };
 
 static PedDiskType msdos_disk_type = {
diff --git a/libparted/labels/dvh.c b/libparted/labels/dvh.c
index 8d8ba76..bdea1c7 100644
--- a/libparted/labels/dvh.c
+++ b/libparted/labels/dvh.c
@@ -888,7 +888,8 @@ static PedDiskOps dvh_disk_ops = {
 
 	alloc_metadata:		dvh_alloc_metadata,
 	get_max_primary_partition_count:
-				dvh_get_max_primary_partition_count
+				dvh_get_max_primary_partition_count,
+	get_max_partition_count: dvh_get_max_primary_partition_count
 };
 
 static PedDiskType dvh_disk_type = {
diff --git a/libparted/labels/gpt.c b/libparted/labels/gpt.c
index eea562d..6c9929b 100644
--- a/libparted/labels/gpt.c
+++ b/libparted/labels/gpt.c
@@ -1470,6 +1470,12 @@ gpt_get_max_primary_partition_count (const PedDisk *disk)
 	return gpt_disk_data->entry_count;
 }
 
+static int
+gpt_get_max_partitoin_count(const PedDisk *disk)
+{
+	return 16;
+}
+
 static PedConstraint*
 _non_metadata_constraint (const PedDisk* disk)
 {
@@ -1524,7 +1530,8 @@ static PedDiskOps gpt_disk_ops = {
 	partition_align:		gpt_partition_align,
 	partition_enumerate:		gpt_partition_enumerate,
 	alloc_metadata:			gpt_alloc_metadata,
-	get_max_primary_partition_count: gpt_get_max_primary_partition_count
+	get_max_primary_partition_count: gpt_get_max_primary_partition_count,
+	get_max_partition_count: gpt_get_max_partitoin_count
 };
 
 static PedDiskType gpt_disk_type = {
diff --git a/libparted/labels/loop.c b/libparted/labels/loop.c
index a6a2057..19181ee 100644
--- a/libparted/labels/loop.c
+++ b/libparted/labels/loop.c
@@ -311,6 +311,8 @@ static PedDiskOps loop_disk_ops = {
 
 	alloc_metadata:		loop_alloc_metadata,
 	get_max_primary_partition_count:
+				loop_get_max_primary_partition_count,
+	get_max_partition_count:
 				loop_get_max_primary_partition_count
 };
 
diff --git a/libparted/labels/mac.c b/libparted/labels/mac.c
index 3ec8390..8f17e8a 100644
--- a/libparted/labels/mac.c
+++ b/libparted/labels/mac.c
@@ -1563,6 +1563,12 @@ mac_get_max_primary_partition_count (const PedDisk* disk)
 		- mac_disk_data->free_part_entry_count + 1;
 }
 
+static int
+mac_get_max_partitoin_count (const PedDisk* disk)
+{
+	return 65536;
+}
+
 static PedDiskOps mac_disk_ops = {
 	probe:			mac_probe,
 #ifndef DISCOVER_ONLY
@@ -1596,7 +1602,9 @@ static PedDiskOps mac_disk_ops = {
 
 	alloc_metadata:		mac_alloc_metadata,
 	get_max_primary_partition_count:
-				mac_get_max_primary_partition_count
+				mac_get_max_primary_partition_count,
+	get_max_partition_count:
+				mac_get_max_partitoin_count
 };
 
 static PedDiskType mac_disk_type = {
diff --git a/libparted/labels/pc98.c b/libparted/labels/pc98.c
index a7b7e57..05e1e45 100644
--- a/libparted/labels/pc98.c
+++ b/libparted/labels/pc98.c
@@ -863,6 +863,8 @@ static PedDiskOps pc98_disk_ops = {
 
 	alloc_metadata:		pc98_alloc_metadata,
 	get_max_primary_partition_count:
+				pc98_get_max_primary_partition_count,
+	get_max_partition_count:
 				pc98_get_max_primary_partition_count
 };
 
diff --git a/libparted/labels/rdb.c b/libparted/labels/rdb.c
index 386b2bd..093d48f 100644
--- a/libparted/labels/rdb.c
+++ b/libparted/labels/rdb.c
@@ -1157,6 +1157,8 @@ static PedDiskOps amiga_disk_ops = {
 
 	alloc_metadata:		amiga_alloc_metadata,
 	get_max_primary_partition_count:
+				amiga_get_max_primary_partition_count,
+	get_max_partition_count:
 				amiga_get_max_primary_partition_count
 };
 
diff --git a/libparted/labels/sun.c b/libparted/labels/sun.c
index 76f2b78..befc2fc 100644
--- a/libparted/labels/sun.c
+++ b/libparted/labels/sun.c
@@ -858,6 +858,8 @@ static PedDiskOps sun_disk_ops = {
 	alloc_metadata:		sun_alloc_metadata,
 	get_max_primary_partition_count:
 				sun_get_max_primary_partition_count,
+	get_max_partition_count:
+				sun_get_max_primary_partition_count,
 
 	partition_set_name:		NULL,
 	partition_get_name:		NULL,
-- 
1.6.0.6




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