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From: Xiao Guangrong <guangrong.xiao@linux.intel.com>
To: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
	pbonzini@redhat.com, imammedo@redhat.com
Cc: ehabkost@redhat.com, kvm@vger.kernel.org, mst@redhat.com,
	gleb@kernel.org, mtosatti@redhat.com, qemu-devel@nongnu.org,
	stefanha@redhat.com, dan.j.williams@intel.com, rth@twiddle.net
Subject: Re: [PATCH v6 09/33] exec: allow file_ram_alloc to work on file
Date: Sat, 31 Oct 2015 15:53:05 +0800	[thread overview]
Message-ID: <56347361.4030300@linux.intel.com> (raw)
In-Reply-To: <56337DD1.8010509@virtuozzo.com>



On 10/30/2015 10:25 PM, Vladimir Sementsov-Ogievskiy wrote:
> On 30.10.2015 08:56, Xiao Guangrong wrote:
>> Currently, file_ram_alloc() only works on directory - it creates a file
>> under @path and do mmap on it
>>
>> This patch tries to allow it to work on file directly, if @path is a
>> directory it works as before, otherwise it treats @path as the target
>> file then directly allocate memory from it
>>
>> Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
>> ---
>>   exec.c | 80 ++++++++++++++++++++++++++++++++++++++++++------------------------
>>   1 file changed, 51 insertions(+), 29 deletions(-)
>>
>> diff --git a/exec.c b/exec.c
>> index 3ca7e50..f219010 100644
>> --- a/exec.c
>> +++ b/exec.c
>> @@ -1174,14 +1174,60 @@ void qemu_mutex_unlock_ramlist(void)
>>   }
>>   #ifdef __linux__
>> +static bool path_is_dir(const char *path)
>> +{
>> +    struct stat fs;
>> +
>> +    return stat(path, &fs) == 0 && S_ISDIR(fs.st_mode);
>> +}
>> +
>> +static int open_file_path(RAMBlock *block, const char *path, size_t size)
>
> I think the name should be more descriptive, as it is very special function in common exec.c and it
> doesn't "just open file path'.. May be open_ram_file_path

Okay, good to me. :)

>
>
>> +{
>> +    char *filename;
>> +    char *sanitized_name;
>> +    char *c;
>> +    int fd;
>> +
>> +    if (!path_is_dir(path)) {
>> +        int flags = (block->flags & RAM_SHARED) ? O_RDWR : O_RDONLY;
>> +
>> +        flags |= O_EXCL;
>> +        return open(path, flags);
>> +    }
>
> Was not there old scenarios when path is file? statfs will  success for any file withing mounted
> filesystem.
>

Yes.

The old scenarios will create a temporary file under the @path that stop regular file's work.


> Also, may be we shouldn't warn about "Memory is not allocated from HugeTlbfs.\n" in case of
> !path_is_dir ?
>

A file from hugetlbfs and attach it as backend memory is a valid case to users.

WARNING: multiple messages have this Message-ID (diff)
From: Xiao Guangrong <guangrong.xiao@linux.intel.com>
To: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
	pbonzini@redhat.com, imammedo@redhat.com
Cc: ehabkost@redhat.com, kvm@vger.kernel.org, mst@redhat.com,
	gleb@kernel.org, mtosatti@redhat.com, qemu-devel@nongnu.org,
	stefanha@redhat.com, dan.j.williams@intel.com, rth@twiddle.net
Subject: Re: [Qemu-devel] [PATCH v6 09/33] exec: allow file_ram_alloc to work on file
Date: Sat, 31 Oct 2015 15:53:05 +0800	[thread overview]
Message-ID: <56347361.4030300@linux.intel.com> (raw)
In-Reply-To: <56337DD1.8010509@virtuozzo.com>



On 10/30/2015 10:25 PM, Vladimir Sementsov-Ogievskiy wrote:
> On 30.10.2015 08:56, Xiao Guangrong wrote:
>> Currently, file_ram_alloc() only works on directory - it creates a file
>> under @path and do mmap on it
>>
>> This patch tries to allow it to work on file directly, if @path is a
>> directory it works as before, otherwise it treats @path as the target
>> file then directly allocate memory from it
>>
>> Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
>> ---
>>   exec.c | 80 ++++++++++++++++++++++++++++++++++++++++++------------------------
>>   1 file changed, 51 insertions(+), 29 deletions(-)
>>
>> diff --git a/exec.c b/exec.c
>> index 3ca7e50..f219010 100644
>> --- a/exec.c
>> +++ b/exec.c
>> @@ -1174,14 +1174,60 @@ void qemu_mutex_unlock_ramlist(void)
>>   }
>>   #ifdef __linux__
>> +static bool path_is_dir(const char *path)
>> +{
>> +    struct stat fs;
>> +
>> +    return stat(path, &fs) == 0 && S_ISDIR(fs.st_mode);
>> +}
>> +
>> +static int open_file_path(RAMBlock *block, const char *path, size_t size)
>
> I think the name should be more descriptive, as it is very special function in common exec.c and it
> doesn't "just open file path'.. May be open_ram_file_path

Okay, good to me. :)

>
>
>> +{
>> +    char *filename;
>> +    char *sanitized_name;
>> +    char *c;
>> +    int fd;
>> +
>> +    if (!path_is_dir(path)) {
>> +        int flags = (block->flags & RAM_SHARED) ? O_RDWR : O_RDONLY;
>> +
>> +        flags |= O_EXCL;
>> +        return open(path, flags);
>> +    }
>
> Was not there old scenarios when path is file? statfs will  success for any file withing mounted
> filesystem.
>

Yes.

The old scenarios will create a temporary file under the @path that stop regular file's work.


> Also, may be we shouldn't warn about "Memory is not allocated from HugeTlbfs.\n" in case of
> !path_is_dir ?
>

A file from hugetlbfs and attach it as backend memory is a valid case to users.

  reply	other threads:[~2015-10-31  7:53 UTC|newest]

Thread overview: 182+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-30  5:55 [PATCH v6 00/33] implement vNVDIMM Xiao Guangrong
2015-10-30  5:55 ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:55 ` [PATCH v6 01/33] acpi: add aml_derefof Xiao Guangrong
2015-10-30  5:55   ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:55 ` [PATCH v6 02/33] acpi: add aml_sizeof Xiao Guangrong
2015-10-30  5:55   ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:55 ` [PATCH v6 03/33] acpi: add aml_create_field Xiao Guangrong
2015-10-30  5:55   ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:55 ` [PATCH v6 04/33] acpi: add aml_concatenate Xiao Guangrong
2015-10-30  5:55   ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:55 ` [PATCH v6 05/33] acpi: add aml_object_type Xiao Guangrong
2015-10-30  5:55   ` [Qemu-devel] " Xiao Guangrong
2015-11-09 11:35   ` Michael S. Tsirkin
2015-11-09 11:35     ` [Qemu-devel] " Michael S. Tsirkin
2015-11-09 12:40     ` Igor Mammedov
2015-11-09 12:40       ` [Qemu-devel] " Igor Mammedov
2015-10-30  5:56 ` [PATCH v6 06/33] acpi: add aml_method_serialized Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-11-09 11:14   ` Michael S. Tsirkin
2015-11-09 11:14     ` [Qemu-devel] " Michael S. Tsirkin
2015-11-09 11:18     ` Xiao Guangrong
2015-11-09 11:18       ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 07/33] util: introduce qemu_file_get_page_size() Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30 13:26   ` Vladimir Sementsov-Ogievskiy
2015-10-30 13:26     ` Vladimir Sementsov-Ogievskiy
2015-10-31  7:26     ` Xiao Guangrong
2015-10-31  7:26       ` [Qemu-devel] " Xiao Guangrong
2015-10-31  9:37       ` Vladimir Sementsov-Ogievskiy
2015-10-31  9:37         ` Vladimir Sementsov-Ogievskiy
2015-10-31 14:06         ` Xiao Guangrong
2015-10-31 14:06           ` [Qemu-devel] " Xiao Guangrong
2015-10-30 15:54   ` Eduardo Habkost
2015-10-30 15:54     ` [Qemu-devel] " Eduardo Habkost
2015-10-31  8:09     ` Xiao Guangrong
2015-10-31  8:09       ` [Qemu-devel] " Xiao Guangrong
2015-10-31 14:11       ` Eduardo Habkost
2015-10-31 14:11         ` [Qemu-devel] " Eduardo Habkost
2015-10-31 17:03         ` Xiao Guangrong
2015-10-31 17:03           ` [Qemu-devel] " Xiao Guangrong
2015-11-09 20:00       ` Michael S. Tsirkin
2015-11-09 20:00         ` [Qemu-devel] " Michael S. Tsirkin
2015-10-31  8:25     ` Xiao Guangrong
2015-10-31  8:25       ` [Qemu-devel] " Xiao Guangrong
2015-11-09 10:33   ` Michael S. Tsirkin
2015-11-09 10:33     ` [Qemu-devel] " Michael S. Tsirkin
2015-11-09 10:55     ` Xiao Guangrong
2015-11-09 10:55       ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 08/33] exec: allow memory to be allocated from any kind of path Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30 14:04   ` Vladimir Sementsov-Ogievskiy
2015-10-30 14:04     ` Vladimir Sementsov-Ogievskiy
2015-10-31  7:44     ` Xiao Guangrong
2015-10-31 13:55       ` Eduardo Habkost
2015-10-31 13:55         ` Eduardo Habkost
2015-10-31 15:56         ` Xiao Guangrong
2015-10-31 15:56           ` Xiao Guangrong
2015-11-09 10:39   ` Michael S. Tsirkin
2015-11-09 10:39     ` [Qemu-devel] " Michael S. Tsirkin
2015-11-09 11:01     ` Xiao Guangrong
2015-11-09 11:01       ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 09/33] exec: allow file_ram_alloc to work on file Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30 14:25   ` Vladimir Sementsov-Ogievskiy
2015-10-30 14:25     ` Vladimir Sementsov-Ogievskiy
2015-10-31  7:53     ` Xiao Guangrong [this message]
2015-10-31  7:53       ` Xiao Guangrong
2015-11-09 10:13   ` Michael S. Tsirkin
2015-11-09 10:13     ` [Qemu-devel] " Michael S. Tsirkin
2015-11-09 10:48     ` Xiao Guangrong
2015-11-09 10:48       ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 10/33] hostmem-file: clean up memory allocation Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30 14:54   ` Vladimir Sementsov-Ogievskiy
2015-10-30 14:54     ` Vladimir Sementsov-Ogievskiy
2015-10-30  5:56 ` [PATCH v6 11/33] hostmem-file: use whole file size if possible Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30 15:27   ` Vladimir Sementsov-Ogievskiy
2015-10-30 15:27     ` Vladimir Sementsov-Ogievskiy
2015-10-31  7:59     ` Xiao Guangrong
2015-10-31  7:59       ` [Qemu-devel] " Xiao Guangrong
2015-10-30 17:30   ` Eduardo Habkost
2015-10-30 17:30     ` Eduardo Habkost
2015-10-31  8:46     ` Xiao Guangrong
2015-10-31  8:46       ` Xiao Guangrong
2015-10-31 13:45       ` Eduardo Habkost
2015-10-31 13:45         ` Eduardo Habkost
2015-10-31 16:59         ` Xiao Guangrong
2015-10-31 16:59           ` [Qemu-devel] " Xiao Guangrong
2015-11-09 10:17   ` Michael S. Tsirkin
2015-11-09 10:17     ` [Qemu-devel] " Michael S. Tsirkin
2015-11-09 10:49     ` Xiao Guangrong
2015-11-09 10:49       ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 12/33] pc-dimm: remove DEFAULT_PC_DIMMSIZE Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-11-09 10:40   ` Michael S. Tsirkin
2015-11-09 10:40     ` [Qemu-devel] " Michael S. Tsirkin
2015-11-09 11:03     ` Xiao Guangrong
2015-11-09 11:03       ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 13/33] pc-dimm: make pc_existing_dimms_capacity static and rename it Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30 15:38   ` Vladimir Sementsov-Ogievskiy
2015-10-30 15:38     ` Vladimir Sementsov-Ogievskiy
2015-10-30  5:56 ` [PATCH v6 14/33] pc-dimm: drop the prefix of pc-dimm Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30 16:10   ` Vladimir Sementsov-Ogievskiy
2015-10-30 16:10     ` Vladimir Sementsov-Ogievskiy
2015-10-31  8:18     ` Xiao Guangrong
2015-10-30 17:06   ` Eric Blake
2015-10-31  8:23     ` Xiao Guangrong
2015-11-09 20:05   ` Michael S. Tsirkin
2015-11-09 20:05     ` [Qemu-devel] " Michael S. Tsirkin
2015-10-30  5:56 ` [PATCH v6 15/33] stubs: rename qmp_pc_dimm_device_list.c Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 16/33] pc-dimm: rename pc-dimm.c and pc-dimm.h Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-31 10:28   ` Vladimir Sementsov-Ogievskiy
2015-10-31 10:28     ` Vladimir Sementsov-Ogievskiy
2015-10-30  5:56 ` [PATCH v6 17/33] dimm: abstract dimm device from pc-dimm Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-31 10:41   ` Vladimir Sementsov-Ogievskiy
2015-10-31 10:41     ` [Qemu-devel] " Vladimir Sementsov-Ogievskiy
2015-10-30  5:56 ` [PATCH v6 18/33] dimm: get mapped memory region from DIMMDeviceClass->get_memory_region Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-31 10:52   ` Vladimir Sementsov-Ogievskiy
2015-10-31 10:52     ` Vladimir Sementsov-Ogievskiy
2015-10-31 14:15     ` Xiao Guangrong
2015-10-31 14:15       ` [Qemu-devel] " Xiao Guangrong
2015-11-02  9:18       ` Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 19/33] dimm: keep the state of the whole backend memory Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-31 11:05   ` Vladimir Sementsov-Ogievskiy
2015-10-31 11:05     ` Vladimir Sementsov-Ogievskiy
2015-10-31 14:19     ` Xiao Guangrong
2015-11-09 11:04   ` Michael S. Tsirkin
2015-11-09 11:04     ` [Qemu-devel] " Michael S. Tsirkin
2015-11-09 11:13     ` Xiao Guangrong
2015-11-09 11:13       ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 20/33] dimm: introduce realize callback Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-31 11:22   ` Vladimir Sementsov-Ogievskiy
2015-10-31 11:22     ` [Qemu-devel] " Vladimir Sementsov-Ogievskiy
2015-10-30  5:56 ` [PATCH v6 21/33] nvdimm: implement NVDIMM device abstract Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 22/33] docs: add NVDIMM ACPI documentation Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 23/33] nvdimm acpi: init the resource used by NVDIMM ACPI Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 24/33] nvdimm acpi: build ACPI NFIT table Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 25/33] nvdimm acpi: build ACPI nvdimm devices Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-11-08 17:38   ` Michael S. Tsirkin
2015-11-08 17:38     ` [Qemu-devel] " Michael S. Tsirkin
2015-11-09  6:07     ` Xiao Guangrong
2015-11-09  6:07       ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 26/33] nvdimm acpi: save arg3 for NVDIMM device _DSM method Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 27/33] nvdimm acpi: support function 0 Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30 10:14   ` Stefan Hajnoczi
2015-10-30 10:14     ` [Qemu-devel] " Stefan Hajnoczi
2015-10-30 13:01     ` Xiao Guangrong
2015-10-30 13:01       ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 28/33] nvdimm acpi: support Get Namespace Label Size function Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 29/33] nvdimm acpi: support Get Namespace Label Data function Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 30/33] nvdimm acpi: support Set " Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 31/33] nvdimm: allow using whole backend memory as pmem Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 32/33] nvdimm acpi: support _FIT method Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-11-08 17:50   ` Michael S. Tsirkin
2015-11-08 17:50     ` [Qemu-devel] " Michael S. Tsirkin
2015-11-09  6:37     ` Xiao Guangrong
2015-11-09  6:37       ` [Qemu-devel] " Xiao Guangrong
2015-10-30  5:56 ` [PATCH v6 33/33] nvdimm: add maintain info Xiao Guangrong
2015-10-30  5:56   ` [Qemu-devel] " Xiao Guangrong
2015-10-30 10:15 ` [PATCH v6 00/33] implement vNVDIMM Stefan Hajnoczi
2015-10-30 10:15   ` [Qemu-devel] " Stefan Hajnoczi

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