Attachment 650590 Details for Bug 835622 – add block device discard support to qemu (WIP)

[patch] add block device discard support to qemu (WIP)

835622-qemu-block-discard.patch (text/plain), 2.01 KB, created by Dominic Cleal on 2012-11-23 17:50:32 UTC

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Creator: Dominic Cleal

Created: 2012-11-23 17:50:32 UTC

Size: 2.01 KB

patch

obsolete

>commit 0f63b071eb1b366f2a7364aa735e66e27e578cda
>Author: Dominic Cleal <dcleal@redhat.com>
>Date:   Mon Oct 29 09:34:57 2012 +0000
>
>    Block device discard support
>    
>    * add discard capability to raw POSIX block devices
>    * discard the entire device on block device creation
>
>diff --git a/block/raw-posix.c b/block/raw-posix.c
>index 28d439f..6b34420 100644
>--- a/block/raw-posix.c
>+++ b/block/raw-posix.c
>@@ -108,6 +108,10 @@
> #define O_DIRECT O_DSYNC
> #endif
> 
>+#ifndef BLKDISCARD
>+#define BLKDISCARD _IO(0x12, 119)
>+#endif
>+
> #define FTYPE_FILE   0
> #define FTYPE_CD     1
> #define FTYPE_FD     2
>@@ -1087,6 +1091,7 @@ static int hdev_create(const char *filename, QEMUOptionParameter *options)
>     int ret = 0;
>     struct stat stat_buf;
>     int64_t total_size = 0;
>+    uint64_t range[2];
> 
>     /* Read out options */
>     while (options && options->name) {
>@@ -1107,13 +1112,36 @@ static int hdev_create(const char *filename, QEMUOptionParameter *options)
>     else if (lseek(fd, 0, SEEK_END) < total_size * BDRV_SECTOR_SIZE)
>         ret = -ENOSPC;
> 
>+#ifdef __linux__
>+    /* Zero the device first if possible */
>+    range[0] = 0;
>+    range[1] = total_size * BDRV_SECTOR_SIZE;
>+    if (ioctl(fd, BLKDISCARD, &range))
>+        return -errno;
>+#endif
>+
>     qemu_close(fd);
>     return ret;
> }
> 
> static int hdev_has_zero_init(BlockDriverState *bs)
> {
>+#ifdef __linux__
>+    return 1;
>+#else
>     return 0;
>+#endif
>+}
>+
>+static BlockDriverAIOCB *hdev_aio_discard(BlockDriverState *bs,
>+        int64_t sector_num, int nb_sectors,
>+        BlockDriverCompletionFunc *cb, void *opaque)
>+{
>+    uint64_t range[2];
>+    range[0] = sector_num << BDRV_SECTOR_BITS;
>+    range[1] = nb_sectors << BDRV_SECTOR_BITS;
>+
>+    return hdev_aio_ioctl(bs, BLKDISCARD, &range, cb, opaque);
> }
> 
> static BlockDriver bdrv_host_device = {
>@@ -1140,6 +1168,7 @@ static BlockDriver bdrv_host_device = {
> #ifdef __linux__
>     .bdrv_ioctl         = hdev_ioctl,
>     .bdrv_aio_ioctl     = hdev_aio_ioctl,
>+    .bdrv_aio_discard   = hdev_aio_discard,
> #endif
> };
>

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Attachments on bug 835622: 650590