[Qemu-devel] [PATCH v3 3/5] block: Add driver methods to probe blocksizes and geometry

[Ekaterina Tumanova]

This patch introduces driver methods of defining disk blocksizes
(physical and logical) and hard drive geometry.
The method is only implemented for "host_device". For "raw" devices
driver calls child's method.

For the time being geometry detection will only work for DASD devices.
In order to check that a local check_for_dasd function was introduced,
which calls BIODASDINFO2 ioctl and returns its rc.

Blocksizes detection fuction will probe sizes for DASD devices and
set default for other devices.

Signed-off-by: Ekaterina Tumanova <address@hidden>
---
 block/raw-posix.c | 91 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 block/raw_bsd.c   | 14 +++++++++
 2 files changed, 105 insertions(+)

diff --git a/block/raw-posix.c b/block/raw-posix.c
index 633d5bc..33f9983 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -56,6 +56,7 @@
 #include <linux/cdrom.h>
 #include <linux/fd.h>
 #include <linux/fs.h>
+#include <linux/hdreg.h>
 #ifndef FS_NOCOW_FL
 #define FS_NOCOW_FL                     0x00800000 /* Do not cow file */
 #endif
@@ -90,6 +91,10 @@
 #include <xfs/xfs.h>
 #endif
 
+#ifdef __s390__
+#include <asm/dasd.h>
+#endif
+
 //#define DEBUG_FLOPPY
 
 //#define DEBUG_BLOCK
@@ -242,6 +247,20 @@ static int probe_logical_blocksize(int fd, unsigned int 
*sector_size)
     return 0;
 }
 
+/*
+ * Set physical block size via ioctl. On success return 0. Otherwise -errno.
+ */
+static int probe_physical_blocksize(int fd, unsigned int *blk_size)
+{
+#ifdef BLKPBSZGET
+    if (ioctl(fd, BLKPBSZGET, blk_size) < 0) {
+        return -errno;
+    }
+#endif
+
+    return 0;
+}
+
 static void raw_probe_alignment(BlockDriverState *bs, int fd, Error **errp)
 {
     BDRVRawState *s = bs->opaque;
@@ -662,6 +681,76 @@ static void raw_refresh_limits(BlockDriverState *bs, Error 
**errp)
     bs->bl.opt_mem_alignment = s->buf_align;
 }
 
+static int check_for_dasd(int fd)
+{
+#ifdef BIODASDINFO2
+    struct dasd_information2_t info = {0};
+
+    return ioctl(fd, BIODASDINFO2, &info);
+#endif
+    return -1;
+}
+
+/*
+ * Try to get the device blocksize. On success 0. On failure return -errno.
+ * Currently only implemented for DASD drives.
+ */
+static int hdev_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
+{
+    BDRVRawState *s = bs->opaque;
+    int ret;
+
+    /* If DASD, get blocksizes */
+    if (check_for_dasd(s->fd) < 0) {
+        return -1;
+    }
+    ret = probe_logical_blocksize(s->fd, &bsz->log);
+    if (ret < 0) {
+        return ret;
+    }
+    return probe_physical_blocksize(s->fd, &bsz->phys);
+}
+
+/*
+ * Try to get the device geometry. On success 0. On failure return -errno.
+ * Currently only implemented for DASD drives.
+ */
+static int hdev_probe_geometry(BlockDriverState *bs, hdGeometry *geo)
+{
+    BDRVRawState *s = bs->opaque;
+    struct hd_geometry ioctl_geo = {0};
+    uint32_t blksize;
+
+    /* If DASD, get it's geometry */
+    if (check_for_dasd(s->fd) < 0) {
+        return -1;
+    }
+    if (ioctl(s->fd, HDIO_GETGEO, &ioctl_geo) < 0) {
+        return -errno;
+    }
+    /* HDIO_GETGEO may return success even though geo contains zeros
+       (e.g. certain multipath setups) */
+    if (!ioctl_geo.heads || !ioctl_geo.sectors || !ioctl_geo.cylinders) {
+        return -1;
+    }
+    /* Do not return a geometry for partition */
+    if (ioctl_geo.start != 0) {
+        return -1;
+    }
+    geo->heads = ioctl_geo.heads;
+    geo->sectors = ioctl_geo.sectors;
+    if (bs->total_sectors) {
+        if (!probe_physical_blocksize(s->fd, &blksize)) {
+            geo->cylinders = bs->total_sectors / (blksize / BDRV_SECTOR_SIZE)
+                                               / (geo->heads * geo->sectors);
+            return 0;
+        }
+    }
+    geo->cylinders = ioctl_geo.cylinders;
+
+    return 0;
+}
+
 static ssize_t handle_aiocb_ioctl(RawPosixAIOData *aiocb)
 {
     int ret;
@@ -2127,6 +2216,8 @@ static BlockDriver bdrv_host_device = {
     .bdrv_get_info = raw_get_info,
     .bdrv_get_allocated_file_size
                         = raw_get_allocated_file_size,
+    .bdrv_probe_blocksizes = hdev_probe_blocksizes,
+    .bdrv_probe_geometry = hdev_probe_geometry,
 
     .bdrv_detach_aio_context = raw_detach_aio_context,
     .bdrv_attach_aio_context = raw_attach_aio_context,
diff --git a/block/raw_bsd.c b/block/raw_bsd.c
index 401b967..cfd5249 100644
--- a/block/raw_bsd.c
+++ b/block/raw_bsd.c
@@ -173,6 +173,18 @@ static int raw_probe(const uint8_t *buf, int buf_size, 
const char *filename)
     return 1;
 }
 
+static int raw_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
+{
+    bdrv_probe_blocksizes(bs->file, bsz);
+
+    return 0;
+}
+
+static int raw_probe_geometry(BlockDriverState *bs, hdGeometry *geo)
+{
+    return bdrv_probe_geometry(bs->file, geo);
+}
+
 static BlockDriver bdrv_raw = {
     .format_name          = "raw",
     .bdrv_probe           = &raw_probe,
@@ -190,6 +202,8 @@ static BlockDriver bdrv_raw = {
     .has_variable_length  = true,
     .bdrv_get_info        = &raw_get_info,
     .bdrv_refresh_limits  = &raw_refresh_limits,
+    .bdrv_probe_blocksizes = &raw_probe_blocksizes,
+    .bdrv_probe_geometry  = &raw_probe_geometry,
     .bdrv_is_inserted     = &raw_is_inserted,
     .bdrv_media_changed   = &raw_media_changed,
     .bdrv_eject           = &raw_eject,
-- 
1.8.5.5