[v3,11/32] hostmem-file: use whole file size if possible
diff mbox

Message ID 1444535584-18220-12-git-send-email-guangrong.xiao@linux.intel.com
State New
Headers show

Commit Message

Xiao Guangrong Oct. 11, 2015, 3:52 a.m. UTC
Use the whole file size if @size is not specified which is useful
if we want to directly pass a file to guest

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
---
 backends/hostmem-file.c | 47 +++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 43 insertions(+), 4 deletions(-)

Comments

Vladimir Sementsov-Ogievskiy Oct. 13, 2015, 11:50 a.m. UTC | #1
On 11.10.2015 06:52, Xiao Guangrong wrote:
> Use the whole file size if @size is not specified which is useful
> if we want to directly pass a file to guest
>
> Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
> ---
>   backends/hostmem-file.c | 47 +++++++++++++++++++++++++++++++++++++++++++----
>   1 file changed, 43 insertions(+), 4 deletions(-)
>
> diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c
> index 9097a57..adf2835 100644
> --- a/backends/hostmem-file.c
> +++ b/backends/hostmem-file.c
> @@ -9,6 +9,9 @@
>    * This work is licensed under the terms of the GNU GPL, version 2 or later.
>    * See the COPYING file in the top-level directory.
>    */
> +#include <sys/ioctl.h>
> +#include <linux/fs.h>
> +
>   #include "qemu-common.h"
>   #include "sysemu/hostmem.h"
>   #include "sysemu/sysemu.h"
> @@ -33,20 +36,56 @@ struct HostMemoryBackendFile {
>       char *mem_path;
>   };
>   
> +static uint64_t get_file_size(const char *file)
> +{
> +    struct stat stat_buf;
> +    uint64_t size = 0;
> +    int fd;
> +
> +    fd = open(file, O_RDONLY);
> +    if (fd < 0) {
> +        return 0;
> +    }
> +
> +    if (stat(file, &stat_buf) < 0) {
> +        goto exit;
> +    }
> +
> +    if ((S_ISBLK(stat_buf.st_mode)) && !ioctl(fd, BLKGETSIZE64, &size)) {
> +        goto exit;
> +    }
> +
> +    size = lseek(fd, 0, SEEK_END);
> +    if (size == -1) {
> +        size = 0;
> +    }
> +exit:
> +    close(fd);
> +    return size;
> +}
> +
>   static void
>   file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
>   {
>       HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(backend);
>   
> -    if (!backend->size) {
> -        error_setg(errp, "can't create backend with size 0");
> -        return;
> -    }
>       if (!fb->mem_path) {
>           error_setg(errp, "mem-path property not set");
>           return;
>       }
>   
> +    if (!backend->size) {
> +        /*
> +         * use the whole file size if @size is not specified.
> +         */
> +        backend->size = get_file_size(fb->mem_path);
> +    }
> +
> +    if (!backend->size) {
> +        error_setg(errp, "can't create backend with size 0");
> +        return;
> +    }

in case of any error in get_file_size (open, stat, lseek) it will write 
about "backend with size 0" which may be not appropriate..

> +
>       backend->force_prealloc = mem_prealloc;
>       memory_region_init_ram_from_file(&backend->mr, OBJECT(backend),
>                                    object_get_canonical_path(OBJECT(backend)),
Xiao Guangrong Oct. 13, 2015, 4:53 p.m. UTC | #2
On 10/13/2015 07:50 PM, Vladimir Sementsov-Ogievskiy wrote:
> On 11.10.2015 06:52, Xiao Guangrong wrote:
>> Use the whole file size if @size is not specified which is useful
>> if we want to directly pass a file to guest
>>
>> Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
>> ---
>>   backends/hostmem-file.c | 47 +++++++++++++++++++++++++++++++++++++++++++----
>>   1 file changed, 43 insertions(+), 4 deletions(-)
>>
>> diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c
>> index 9097a57..adf2835 100644
>> --- a/backends/hostmem-file.c
>> +++ b/backends/hostmem-file.c
>> @@ -9,6 +9,9 @@
>>    * This work is licensed under the terms of the GNU GPL, version 2 or later.
>>    * See the COPYING file in the top-level directory.
>>    */
>> +#include <sys/ioctl.h>
>> +#include <linux/fs.h>
>> +
>>   #include "qemu-common.h"
>>   #include "sysemu/hostmem.h"
>>   #include "sysemu/sysemu.h"
>> @@ -33,20 +36,56 @@ struct HostMemoryBackendFile {
>>       char *mem_path;
>>   };
>> +static uint64_t get_file_size(const char *file)
>> +{
>> +    struct stat stat_buf;
>> +    uint64_t size = 0;
>> +    int fd;
>> +
>> +    fd = open(file, O_RDONLY);
>> +    if (fd < 0) {
>> +        return 0;
>> +    }
>> +
>> +    if (stat(file, &stat_buf) < 0) {
>> +        goto exit;
>> +    }
>> +
>> +    if ((S_ISBLK(stat_buf.st_mode)) && !ioctl(fd, BLKGETSIZE64, &size)) {
>> +        goto exit;
>> +    }
>> +
>> +    size = lseek(fd, 0, SEEK_END);
>> +    if (size == -1) {
>> +        size = 0;
>> +    }
>> +exit:
>> +    close(fd);
>> +    return size;
>> +}
>> +
>>   static void
>>   file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
>>   {
>>       HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(backend);
>> -    if (!backend->size) {
>> -        error_setg(errp, "can't create backend with size 0");
>> -        return;
>> -    }
>>       if (!fb->mem_path) {
>>           error_setg(errp, "mem-path property not set");
>>           return;
>>       }
>> +    if (!backend->size) {
>> +        /*
>> +         * use the whole file size if @size is not specified.
>> +         */
>> +        backend->size = get_file_size(fb->mem_path);
>> +    }
>> +
>> +    if (!backend->size) {
>> +        error_setg(errp, "can't create backend with size 0");
>> +        return;
>> +    }
>
> in case of any error in get_file_size (open, stat, lseek) it will write about "backend with size 0"
> which may be not appropriate..

Okay, i will change it to:
("failed to get file size for %s, can't create backend on it", mem_path);
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Patch
diff mbox

diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c
index 9097a57..adf2835 100644
--- a/backends/hostmem-file.c
+++ b/backends/hostmem-file.c
@@ -9,6 +9,9 @@ 
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  * See the COPYING file in the top-level directory.
  */
+#include <sys/ioctl.h>
+#include <linux/fs.h>
+
 #include "qemu-common.h"
 #include "sysemu/hostmem.h"
 #include "sysemu/sysemu.h"
@@ -33,20 +36,56 @@  struct HostMemoryBackendFile {
     char *mem_path;
 };
 
+static uint64_t get_file_size(const char *file)
+{
+    struct stat stat_buf;
+    uint64_t size = 0;
+    int fd;
+
+    fd = open(file, O_RDONLY);
+    if (fd < 0) {
+        return 0;
+    }
+
+    if (stat(file, &stat_buf) < 0) {
+        goto exit;
+    }
+
+    if ((S_ISBLK(stat_buf.st_mode)) && !ioctl(fd, BLKGETSIZE64, &size)) {
+        goto exit;
+    }
+
+    size = lseek(fd, 0, SEEK_END);
+    if (size == -1) {
+        size = 0;
+    }
+exit:
+    close(fd);
+    return size;
+}
+
 static void
 file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
 {
     HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(backend);
 
-    if (!backend->size) {
-        error_setg(errp, "can't create backend with size 0");
-        return;
-    }
     if (!fb->mem_path) {
         error_setg(errp, "mem-path property not set");
         return;
     }
 
+    if (!backend->size) {
+        /*
+         * use the whole file size if @size is not specified.
+         */
+        backend->size = get_file_size(fb->mem_path);
+    }
+
+    if (!backend->size) {
+        error_setg(errp, "can't create backend with size 0");
+        return;
+    }
+
     backend->force_prealloc = mem_prealloc;
     memory_region_init_ram_from_file(&backend->mr, OBJECT(backend),
                                  object_get_canonical_path(OBJECT(backend)),