[Qemu-devel] [PATCH 3/4] blocksize: Add driver method to get the blocksizes

[Ekaterina Tumanova]

This patch introduces a new method of defining the physical
and logical blocksizes for "raw" and "host_device" drivers.
It uses various ioctls to determine the logical and physical
blocksizes.

For detecting the logical size it uses ioctl calls, that
were previously coded in raw_probe_alignment (now moved into
separate function probe_logical_blocksize). For detecting the
physical blocksize it uses BLKPBSZGET ioctl.

For "raw" devices driver calls the child's method.

Signed-off-by: Ekaterina Tumanova <address@hidden>
Reviewed-by: David Hildenbrand <address@hidden>
Acked-by: Cornelia Huck <address@hidden>
---
 block/raw-posix.c | 69 ++++++++++++++++++++++++++++++++++++++++---------------
 block/raw_bsd.c   | 14 +++++++++++
 2 files changed, 64 insertions(+), 19 deletions(-)

diff --git a/block/raw-posix.c b/block/raw-posix.c
index 8e9758e..6e0d80c 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -221,50 +221,70 @@ static int raw_normalize_devicepath(const char **filename)
 }
 #endif
 
-static void raw_probe_alignment(BlockDriverState *bs, int fd, Error **errp)
+static unsigned int probe_logical_blocksize(BlockDriverState *bs, int fd)
 {
-    BDRVRawState *s = bs->opaque;
-    char *buf;
-    unsigned int sector_size;
-
-    /* For /dev/sg devices the alignment is not really used.
-       With buffered I/O, we don't have any restrictions. */
-    if (bs->sg || !(s->open_flags & O_DIRECT)) {
-        bs->request_alignment = 1;
-        s->buf_align = 1;
-        return;
-    }
+    unsigned int sector_size = 0;
 
     /* Try a few ioctls to get the right size */
-    bs->request_alignment = 0;
-    s->buf_align = 0;
-
 #ifdef BLKSSZGET
     if (ioctl(fd, BLKSSZGET, &sector_size) >= 0) {
-        bs->request_alignment = sector_size;
+        return sector_size;
     }
 #endif
 #ifdef DKIOCGETBLOCKSIZE
     if (ioctl(fd, DKIOCGETBLOCKSIZE, &sector_size) >= 0) {
-        bs->request_alignment = sector_size;
+        return sector_size;
     }
 #endif
 #ifdef DIOCGSECTORSIZE
     if (ioctl(fd, DIOCGSECTORSIZE, &sector_size) >= 0) {
-        bs->request_alignment = sector_size;
+        return sector_size;
     }
 #endif
 #ifdef CONFIG_XFS
     if (s->is_xfs) {
         struct dioattr da;
         if (xfsctl(NULL, fd, XFS_IOC_DIOINFO, &da) >= 0) {
-            bs->request_alignment = da.d_miniosz;
+            sector_size = da.d_miniosz;
             /* The kernel returns wrong information for d_mem */
             /* s->buf_align = da.d_mem; */
+            return sector_size;
         }
     }
 #endif
 
+    return 0;
+}
+
+static unsigned int probe_physical_blocksize(BlockDriverState *bs, int fd)
+{
+    unsigned int blk_size = 0;
+#ifdef BLKPBSZGET
+    if (ioctl(fd, BLKPBSZGET, &blk_size) >= 0) {
+        return blk_size;
+    }
+#endif
+
+    return 0;
+}
+
+static void raw_probe_alignment(BlockDriverState *bs, int fd, Error **errp)
+{
+    BDRVRawState *s = bs->opaque;
+    char *buf;
+
+    /* For /dev/sg devices the alignment is not really used.
+       With buffered I/O, we don't have any restrictions. */
+    if (bs->sg || !(s->open_flags & O_DIRECT)) {
+        bs->request_alignment = 1;
+        s->buf_align = 1;
+        return;
+    }
+
+    s->buf_align = 0;
+    /* Let's try to use the logical blocksize for the alignment. */
+    bs->request_alignment = probe_logical_blocksize(bs, fd);
+
     /* If we could not get the sizes so far, we can only guess them */
     if (!s->buf_align) {
         size_t align;
@@ -642,6 +662,16 @@ static void raw_refresh_limits(BlockDriverState *bs, Error 
**errp)
     bs->bl.opt_mem_alignment = s->buf_align;
 }
 
+static int hdev_probe_blocksizes(BlockDriverState *bs)
+{
+    BDRVRawState *s = bs->opaque;
+
+    bs->logical_block_size = probe_logical_blocksize(bs, s->fd);
+    bs->physical_block_size = probe_physical_blocksize(bs, s->fd);
+
+    return 0;
+}
+
 static ssize_t handle_aiocb_ioctl(RawPosixAIOData *aiocb)
 {
     int ret;
@@ -2009,6 +2039,7 @@ 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_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 f82f4c2..ae400a6 100644
--- a/block/raw_bsd.c
+++ b/block/raw_bsd.c
@@ -173,6 +173,19 @@ static int raw_probe(const uint8_t *buf, int buf_size, 
const char *filename)
     return 1;
 }
 
+static int raw_probe_blocksizes(BlockDriverState *bs)
+{
+    int ret;
+
+    ret = bdrv_probe_blocksizes(bs->file);
+    if (ret == 0) {
+        bs->logical_block_size = bs->file->logical_block_size;
+        bs->physical_block_size = bs->file->physical_block_size;
+    }
+
+    return ret;
+}
+
 static BlockDriver bdrv_raw = {
     .format_name          = "raw",
     .bdrv_probe           = &raw_probe,
@@ -190,6 +203,7 @@ 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_is_inserted     = &raw_is_inserted,
     .bdrv_media_changed   = &raw_media_changed,
     .bdrv_eject           = &raw_eject,
-- 
1.8.5.5