Re: [Qemu-devel] [PATCH 1/2] virtio-9p: make virtio-9p available to all POSIX systems

[Venkateswararao Jujjuri (JV)]

Blue Swirl wrote:
> On Mon, May 24, 2010 at 8:46 PM, Venkateswararao Jujjuri (JV)
> <address@hidden> wrote:
>> Blue Swirl wrote:
>>> Field d_off in struct dirent is Linux specific.
>>>
>>> Signed-off-by: Blue Swirl <address@hidden>
>>> ---
>>>  Makefile.objs   |    8 ++++----
>>>  Makefile.target |    2 +-
>>>  hw/virtio-9p.c  |    2 +-
>>>  hw/virtio-pci.c |    6 +++---
>>>  hw/virtio.h     |    4 ++--
>>>  qemu-config.c   |    4 ++--
>>>  qemu-config.h   |    2 +-
>>>  qemu-options.hx |    8 ++++----
>>>  vl.c            |    8 ++++----
>>>  9 files changed, 22 insertions(+), 22 deletions(-)
>>>
>>> diff --git a/Makefile.objs b/Makefile.objs
>>> index 1585101..b1a6e01 100644
>>> --- a/Makefile.objs
>>> +++ b/Makefile.objs
>>> @@ -35,8 +35,8 @@ net-nested-$(CONFIG_SLIRP) += slirp.o
>>>  net-nested-$(CONFIG_VDE) += vde.o
>>>  net-obj-y += $(addprefix net/, $(net-nested-y))
>>>
>>> -fsdev-nested-$(CONFIG_LINUX) = qemu-fsdev.o
>>> -fsdev-obj-$(CONFIG_LINUX) += $(addprefix fsdev/, $(fsdev-nested-y))
>>> +fsdev-nested-$(CONFIG_POSIX) = qemu-fsdev.o
>>> +fsdev-obj-$(CONFIG_POSIX) += $(addprefix fsdev/, $(fsdev-nested-y))
>>>
>>>  ######################################################################
>>>  # libqemu_common.a: Target independent part of system emulation. The
>>> @@ -47,7 +47,7 @@ fsdev-obj-$(CONFIG_LINUX) += $(addprefix fsdev/,
>>> $(fsdev-nested-y))
>>>  common-obj-y = $(block-obj-y)
>>>  common-obj-y += $(net-obj-y)
>>>  common-obj-y += $(qobject-obj-y)
>>> -common-obj-$(CONFIG_LINUX) += $(fsdev-obj-$(CONFIG_LINUX))
>>> +common-obj-$(CONFIG_POSIX) += $(fsdev-obj-$(CONFIG_POSIX))
>>>  common-obj-y += readline.o console.o async.o qemu-error.o
>>>  common-obj-y += tcg-runtime.o host-utils.o
>>>  common-obj-y += irq.o ioport.o input.o
>>> @@ -229,7 +229,7 @@ sound-obj-$(CONFIG_CS4231A) += cs4231a.o
>>>  adlib.o fmopl.o: QEMU_CFLAGS += -DBUILD_Y8950=0
>>>  hw-obj-$(CONFIG_SOUND) += $(sound-obj-y)
>>>
>>> -hw-obj-$(CONFIG_LINUX) += virtio-9p-debug.o virtio-9p-local.o
>>> +hw-obj-$(CONFIG_POSIX) += virtio-9p-debug.o virtio-9p-local.o
>>>
>>>  ######################################################################
>>>  # libdis
>>> diff --git a/Makefile.target b/Makefile.target
>>> index fda5bf3..00e140f 100644
>>> --- a/Makefile.target
>>> +++ b/Makefile.target
>>> @@ -168,7 +168,7 @@ obj-y += virtio-blk.o virtio-balloon.o
>>> virtio-net.o virtio-serial-bus.o
>>>  obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
>>>  obj-y += vhost_net.o
>>>  obj-$(CONFIG_VHOST_NET) += vhost.o
>>> -obj-$(CONFIG_LINUX) += virtio-9p.o
>>> +obj-$(CONFIG_POSIX) += virtio-9p.o
>>>  obj-y += rwhandler.o
>>>  obj-$(CONFIG_KVM) += kvm.o kvm-all.o
>>>  obj-$(CONFIG_NO_KVM) += kvm-stub.o
>>> diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c
>>> index e5d0112..68b0696 100644
>>> --- a/hw/virtio-9p.c
>>> +++ b/hw/virtio-9p.c
>>> @@ -1447,8 +1447,8 @@ static void v9fs_read_post_dir_lstat(V9fsState
>>> *s, V9fsReadState *vs,
>>>      vs->count += vs->len;
>>>      v9fs_stat_free(&vs->v9stat);
>>>      v9fs_string_free(&vs->name);
>>> -    vs->dir_pos = vs->dent->d_off;
>>>      vs->dent = v9fs_do_readdir(s, vs->fidp->dir);
>>> +    vs->dir_pos = v9fs_do_telldir(s, vs->fidp->dir);
>>
>> We need to save the the current dir position before making next readdir
>> We need to seek back if we can't fit it into PDU.
>> Hence moving the dir_pos after readdir is not a good idea.
> 
> Hmm, the manual page for readdir says:
>        On Linux, the dirent structure is defined as follows:
> 
>            struct dirent {
>                ino_t          d_ino;       /* inode number */
>                off_t          d_off;       /* offset to the next dirent */
>                unsigned short d_reclen;    /* length of this record */
>                unsigned char  d_type;      /* type of file */
>                char           d_name[256]; /* filename */
>            };
> 
> My change was based on the comment for d_off.
> 
> But when I run this program:
> 
> $ cat dirent.c
> #include <sys/types.h>
> #include <dirent.h>
> #include <stdio.h>
> 
> int main(int argc, const char **argv)
> {
>     DIR *d;
>     struct dirent *entry;
>     off_t pos;
> 
>     d = opendir(argv[1]);
>     entry = readdir(d);
>     do {
>         pos = telldir(d);
>         printf("name %s d_off %ld ino %ld pos %ld\n", entry->d_name,
> entry->d_off, entry->d_ino, pos);
>         entry = readdir(d);
>     } while (entry);
>     closedir(d);
> 
>     return 0;
> }
> 
> d_off is equal to telldir value:

I don't think there is any dispute there.. All I am saying is 

Your diff was this:

-    vs->dir_pos = vs->dent->d_off;
      vs->dent = v9fs_do_readdir(s, vs->fidp->dir);
+    vs->dir_pos = v9fs_do_telldir(s, vs->fidp->dir);


It should be:
-    vs->dir_pos = vs->dent->d_off;
+   vs->dir_pos = v9fs_do_telldir(s, vs->fidp->dir);
      vs->dent = v9fs_do_readdir(s, vs->fidp->dir);


> $ ./dirent /
> name tmp d_off 206002973 ino 56 pos 206002973
> name root d_off 224116791 ino 521217 pos 224116791
> name vmlinuz.old d_off 255549115 ino 17 pos 255549115
> name dev d_off 378658993 ino 374625 pos 378658993
> 
> I'll send an updated patch.
> 
>> BTW, Thanks for making VirtFS generic to all POSIX systems.
>>
>> Thanks,
>> JV.
>>
>>>      v9fs_read_post_readdir(s, vs, err);
>>>      return;
>>>  out:
>>> diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
>>> index 7ddf612..0a74781 100644
>>> --- a/hw/virtio-pci.c
>>> +++ b/hw/virtio-pci.c
>>> @@ -102,7 +102,7 @@ typedef struct {
>>>      BlockConf block;
>>>      NICConf nic;
>>>      uint32_t host_features;
>>> -#ifdef CONFIG_LINUX
>>> +#ifdef CONFIG_POSIX
>>>      V9fsConf fsconf;
>>>  #endif
>>>      /* Max. number of ports we can have for a the virtio-serial device */
>>> @@ -642,7 +642,7 @@ static int virtio_balloon_init_pci(PCIDevice *pci_dev)
>>>      return 0;
>>>  }
>>>
>>> -#ifdef CONFIG_LINUX
>>> +#ifdef CONFIG_POSIX
>>>  static int virtio_9p_init_pci(PCIDevice *pci_dev)
>>>  {
>>>      VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
>>> @@ -713,7 +713,7 @@ static PCIDeviceInfo virtio_info[] = {
>>>          },
>>>          .qdev.reset = virtio_pci_reset,
>>>      },{
>>> -#ifdef CONFIG_LINUX
>>> +#ifdef CONFIG_POSIX
>>>          .qdev.name = "virtio-9p-pci",
>>>          .qdev.size = sizeof(VirtIOPCIProxy),
>>>          .init      = virtio_9p_init_pci,
>>> diff --git a/hw/virtio.h b/hw/virtio.h
>>> index e4306cd..e77af13 100644
>>> --- a/hw/virtio.h
>>> +++ b/hw/virtio.h
>>> @@ -20,7 +20,7 @@
>>>  #include "sysemu.h"
>>>  #include "block_int.h"
>>>  #include "event_notifier.h"
>>> -#ifdef CONFIG_LINUX
>>> +#ifdef CONFIG_POSIX
>>>  #include "9p.h"
>>>  #endif
>>>
>>> @@ -188,7 +188,7 @@ VirtIODevice *virtio_blk_init(DeviceState *dev,
>>> BlockConf *conf);
>>>  VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf);
>>>  VirtIODevice *virtio_serial_init(DeviceState *dev, uint32_t max_nr_ports);
>>>  VirtIODevice *virtio_balloon_init(DeviceState *dev);
>>> -#ifdef CONFIG_LINUX
>>> +#ifdef CONFIG_POSIX
>>>  VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf);
>>>  #endif
>>>
>>> diff --git a/qemu-config.c b/qemu-config.c
>>> index d500885..78e80e3 100644
>>> --- a/qemu-config.c
>>> +++ b/qemu-config.c
>>> @@ -151,7 +151,7 @@ QemuOptsList qemu_chardev_opts = {
>>>      },
>>>  };
>>>
>>> -#ifdef CONFIG_LINUX
>>> +#ifdef CONFIG_POSIX
>>>  QemuOptsList qemu_fsdev_opts = {
>>>      .name = "fsdev",
>>>      .implied_opt_name = "fstype",
>>> @@ -169,7 +169,7 @@ QemuOptsList qemu_fsdev_opts = {
>>>  };
>>>  #endif
>>>
>>> -#ifdef CONFIG_LINUX
>>> +#ifdef CONFIG_POSIX
>>>  QemuOptsList qemu_virtfs_opts = {
>>>      .name = "virtfs",
>>>      .implied_opt_name = "fstype",
>>> diff --git a/qemu-config.h b/qemu-config.h
>>> index dca69d4..5376935 100644
>>> --- a/qemu-config.h
>>> +++ b/qemu-config.h
>>> @@ -3,7 +3,7 @@
>>>
>>>  extern QemuOptsList qemu_drive_opts;
>>>  extern QemuOptsList qemu_chardev_opts;
>>> -#ifdef CONFIG_LINUX
>>> +#ifdef CONFIG_POSIX
>>>  extern QemuOptsList qemu_fsdev_opts;
>>>  extern QemuOptsList qemu_virtfs_opts;
>>>  #endif
>>> diff --git a/qemu-options.hx b/qemu-options.hx
>>> index 03e95fd..34ed806 100644
>>> --- a/qemu-options.hx
>>> +++ b/qemu-options.hx
>>> @@ -475,7 +475,7 @@ possible drivers and properties, use @code{-device ?} 
>>> and
>>>  @code{-device @var{driver},?}.
>>>  ETEXI
>>>
>>> -#ifdef CONFIG_LINUX
>>> +#ifdef CONFIG_POSIX
>>>  DEFHEADING(File system options:)
>>>
>>>  DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
>>> @@ -499,7 +499,7 @@ Options to each backend are described below.
>>>
>>>  Create a file-system-"device" for local-filesystem.
>>>
>>> address@hidden is only available on Linux.
>>> address@hidden is only available on POSIX systems.
>>>
>>>  @option{path} specifies the path to be exported. @option{path} is required.
>>>
>>> @@ -507,7 +507,7 @@ Create a file-system-"device" for local-filesystem.
>>>  ETEXI
>>>  #endif
>>>
>>> -#ifdef CONFIG_LINUX
>>> +#ifdef CONFIG_POSIX
>>>  DEFHEADING(Virtual File system pass-through options:)
>>>
>>>  DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
>>> @@ -531,7 +531,7 @@ Options to each backend are described below.
>>>
>>>  Create a Virtual file-system-pass through for local-filesystem.
>>>
>>> address@hidden is only available on Linux.
>>> address@hidden is only available on POSIX systems.
>>>
>>>  @option{path} specifies the path to be exported. @option{path} is required.
>>>
>>> diff --git a/vl.c b/vl.c
>>> index d77b47c..d5c1e34 100644
>>> --- a/vl.c
>>> +++ b/vl.c
>>> @@ -149,7 +149,7 @@ int main(int argc, char **argv)
>>>  #include "qemu-option.h"
>>>  #include "qemu-config.h"
>>>  #include "qemu-objects.h"
>>> -#ifdef CONFIG_LINUX
>>> +#ifdef CONFIG_POSIX
>>>  #include "fsdev/qemu-fsdev.h"
>>>  #endif
>>>
>>> @@ -2314,7 +2314,7 @@ static int chardev_init_func(QemuOpts *opts, void 
>>> *opaque)
>>>      return 0;
>>>  }
>>>
>>> -#ifdef CONFIG_LINUX
>>> +#ifdef CONFIG_POSIX
>>>  static int fsdev_init_func(QemuOpts *opts, void *opaque)
>>>  {
>>>      int ret;
>>> @@ -3090,7 +3090,7 @@ int main(int argc, char **argv, char **envp)
>>>                      exit(1);
>>>                  }
>>>                  break;
>>> -#ifdef CONFIG_LINUX
>>> +#ifdef CONFIG_POSIX
>>>              case QEMU_OPTION_fsdev:
>>>                  opts = qemu_opts_parse(&qemu_fsdev_opts, optarg, 1);
>>>                  if (!opts) {
>>> @@ -3513,7 +3513,7 @@ int main(int argc, char **argv, char **envp)
>>>
>>>      if (qemu_opts_foreach(&qemu_chardev_opts, chardev_init_func, NULL, 1) 
>>> != 0)
>>>          exit(1);
>>> -#ifdef CONFIG_LINUX
>>> +#ifdef CONFIG_POSIX
>>>      if (qemu_opts_foreach(&qemu_fsdev_opts, fsdev_init_func, NULL, 1) != 
>>> 0) {
>>>          exit(1);
>>>      }
>>
>>