diff mbox

[RFC,v11,5/6] raw-posix: Add falloc and full preallocation option

Message ID 8dacb5b0b38ccb69f64ee08d3a4ba6998b65889d.1404287261.git.hutao@cn.fujitsu.com
State New
Headers show

Commit Message

Hu Tao July 2, 2014, 8:17 a.m. UTC 
This patch adds a new option preallocation for raw format, and implements
falloc and full preallocation.

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
---
 block/raw-posix.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 55 insertions(+), 7 deletions(-)

Comments

Max Reitz July 3, 2014, 8:10 p.m. UTC | #1 
On 02.07.2014 10:17, Hu Tao wrote:
> This patch adds a new option preallocation for raw format, and implements
> falloc and full preallocation.
>
> Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
> ---
>   block/raw-posix.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++-------
>   1 file changed, 55 insertions(+), 7 deletions(-)
>
> diff --git a/block/raw-posix.c b/block/raw-posix.c
> index 58c51d8..5dcd465 100644
> --- a/block/raw-posix.c
> +++ b/block/raw-posix.c
> @@ -30,6 +30,7 @@
>   #include "block/thread-pool.h"
>   #include "qemu/iov.h"
>   #include "raw-aio.h"
> +#include "qapi/util.h"
>   
>   #if defined(__APPLE__) && (__MACH__)
>   #include <paths.h>
> @@ -1278,28 +1279,70 @@ static int raw_create(const char *filename, QemuOpts *opts, Error **errp)
>       int fd;
>       int result = 0;
>       int64_t total_size = 0;
> +    PreallocMode prealloc = PREALLOC_MODE_OFF;
> +    char *buf = NULL;

It's not really necessary to initialize these two here, but it won't 
hurt either, of course (same thing later with num, which could have even 
been declared inside of the while loop).

Reviewed-by: Max Reitz <mreitz@redhat.com>
diff mbox

Patch

diff --git a/block/raw-posix.c b/block/raw-posix.c
index 58c51d8..5dcd465 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -30,6 +30,7 @@ 
 #include "block/thread-pool.h"
 #include "qemu/iov.h"
 #include "raw-aio.h"
+#include "qapi/util.h"
 
 #if defined(__APPLE__) && (__MACH__)
 #include <paths.h>
@@ -1278,28 +1279,70 @@  static int raw_create(const char *filename, QemuOpts *opts, Error **errp)
     int fd;
     int result = 0;
     int64_t total_size = 0;
+    PreallocMode prealloc = PREALLOC_MODE_OFF;
+    char *buf = NULL;
+    Error *local_err = NULL;
 
     strstart(filename, "file:", &filename);
 
     /* Read out options */
     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
                           BDRV_SECTOR_SIZE);
+    buf = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC);
+    prealloc = qapi_enum_parse(PreallocMode_lookup, buf,
+                               PREALLOC_MODE_MAX, PREALLOC_MODE_OFF,
+                               &local_err);
+    g_free(buf);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        result = -EINVAL;
+        goto out;
+    }
 
     fd = qemu_open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
                    0644);
     if (fd < 0) {
         result = -errno;
         error_setg_errno(errp, -result, "Could not create file");
-    } else {
-        if (ftruncate(fd, total_size) != 0) {
-            result = -errno;
-            error_setg_errno(errp, -result, "Could not resize file");
+        goto out;
+    }
+    if (ftruncate(fd, total_size) != 0) {
+        result = -errno;
+        error_setg_errno(errp, -result, "Could not resize file");
+        goto out_close;
+    }
+    if (prealloc == PREALLOC_MODE_FALLOC) {
+        /* posix_fallocate() doesn't set errno. */
+        result = -posix_fallocate(fd, 0, total_size);
+        if (result != 0) {
+            error_setg_errno(errp, -result,
+                             "Could not preallocate data for the new file");
         }
-        if (qemu_close(fd) != 0) {
-            result = -errno;
-            error_setg_errno(errp, -result, "Could not close the new file");
+    } else if (prealloc == PREALLOC_MODE_FULL) {
+        buf = g_malloc0(65536);
+        int64_t num = 0, left = total_size;
+
+        while (left > 0) {
+            num = MIN(left, 65536);
+            result = write(fd, buf, num);
+            if (result < 0) {
+                result = -errno;
+                error_setg_errno(errp, -result,
+                                 "Could not write to the new file");
+                g_free(buf);
+                goto out_close;
+            }
+            left -= num;
         }
+        fsync(fd);
+        g_free(buf);
+    }
+out_close:
+    if (qemu_close(fd) != 0 && result == 0) {
+        result = -errno;
+        error_setg_errno(errp, -result, "Could not close the new file");
     }
+out:
     return result;
 }
 
@@ -1477,6 +1520,11 @@  static QemuOptsList raw_create_opts = {
             .type = QEMU_OPT_SIZE,
             .help = "Virtual disk size"
         },
+        {
+            .name = BLOCK_OPT_PREALLOC,
+            .type = QEMU_OPT_STRING,
+            .help = "Preallocation mode (allowed values: off, falloc, full)"
+        },
         { /* end of list */ }
     }
 };