Patchwork [04/17] virtio-9p: Implement P9_TSTAT

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Submitter Anthony Liguori
Date March 3, 2010, 7:01 p.m.
Message ID <1267642874-15001-6-git-send-email-aliguori@us.ibm.com>
Download mbox | patch
Permalink /patch/46858/
State New
Headers show

Comments

Anthony Liguori - March 3, 2010, 7:01 p.m.
This get the mount to work on the guest

[kiran@linux.vnet.ibm.com: malloc to qemu_malloc conversion]

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 hw/virtio-9p-local.c |    7 ++
 hw/virtio-9p.c       |  169 +++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 174 insertions(+), 2 deletions(-)
malc - March 3, 2010, 8:35 p.m.
On Wed, 3 Mar 2010, Anthony Liguori wrote:

> This get the mount to work on the guest
> 
> [kiran@linux.vnet.ibm.com: malloc to qemu_malloc conversion]
> 
> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
> Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
>  hw/virtio-9p-local.c |    7 ++
>  hw/virtio-9p.c       |  169 +++++++++++++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 174 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/virtio-9p-local.c b/hw/virtio-9p-local.c
> index 204437c..9752f76 100644
> --- a/hw/virtio-9p-local.c
> +++ b/hw/virtio-9p-local.c
> @@ -72,9 +72,16 @@ static int local_setuid(void *opaque, uid_t uid)
>      return 0;
>  }
>  
> +static ssize_t local_readlink(void *opaque, const char *path,
> +			      char *buf, size_t bufsz)
> +{
> +    return readlink(rpath(path), buf, bufsz);
> +}
> +
>  static V9fsPosixFileOperations ops = {
>      .lstat = local_lstat,
>      .setuid = local_setuid,
> +    .readlink = local_readlink,
>  };
>  
>  V9fsPosixFileOperations *virtio_9p_init_local(const char *path)
> diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c
> index c63ac80..10bcd89 100644
> --- a/hw/virtio-9p.c
> +++ b/hw/virtio-9p.c
> @@ -102,6 +102,21 @@ static int posix_setuid(V9fsState *s, uid_t uid)
>      return s->ops->setuid(s->ops->opaque, uid);
>  }
>  
> +static ssize_t posix_readlink(V9fsState *s, V9fsString *path, V9fsString *buf)
> +{
> +    ssize_t len;
> +
> +    buf->data = qemu_malloc(1024);
> +
> +    len = s->ops->readlink(s->ops->opaque, path->data, buf->data, 1024 - 1);
> +    if (len > -1) {
> +	buf->size = len;
> +	buf->data[len] = 0;
> +    }
> +
> +    return len;
> +}
> +
>  static void v9fs_string_free(V9fsString *str)
>  {
>      free(str->data);

Should be qemu_free, no?

[..snip..]
Aneesh Kumar K.V - March 4, 2010, 2:15 p.m.
On Wed, 3 Mar 2010 23:35:36 +0300 (MSK), malc <av1474@comtv.ru> wrote:
> On Wed, 3 Mar 2010, Anthony Liguori wrote:
> 
> > This get the mount to work on the guest
> > 
> > [kiran@linux.vnet.ibm.com: malloc to qemu_malloc conversion]
> > 
> > Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
> > Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
> > Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> > ---
> >  hw/virtio-9p-local.c |    7 ++
> >  hw/virtio-9p.c       |  169 +++++++++++++++++++++++++++++++++++++++++++++++++-
> >  2 files changed, 174 insertions(+), 2 deletions(-)
> > 
> > diff --git a/hw/virtio-9p-local.c b/hw/virtio-9p-local.c
> > index 204437c..9752f76 100644
> > --- a/hw/virtio-9p-local.c
> > +++ b/hw/virtio-9p-local.c
> > @@ -72,9 +72,16 @@ static int local_setuid(void *opaque, uid_t uid)
> >      return 0;
> >  }
> >  
> > +static ssize_t local_readlink(void *opaque, const char *path,
> > +			      char *buf, size_t bufsz)
> > +{
> > +    return readlink(rpath(path), buf, bufsz);
> > +}
> > +
> >  static V9fsPosixFileOperations ops = {
> >      .lstat = local_lstat,
> >      .setuid = local_setuid,
> > +    .readlink = local_readlink,
> >  };
> >  
> >  V9fsPosixFileOperations *virtio_9p_init_local(const char *path)
> > diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c
> > index c63ac80..10bcd89 100644
> > --- a/hw/virtio-9p.c
> > +++ b/hw/virtio-9p.c
> > @@ -102,6 +102,21 @@ static int posix_setuid(V9fsState *s, uid_t uid)
> >      return s->ops->setuid(s->ops->opaque, uid);
> >  }
> >  
> > +static ssize_t posix_readlink(V9fsState *s, V9fsString *path, V9fsString *buf)
> > +{
> > +    ssize_t len;
> > +
> > +    buf->data = qemu_malloc(1024);
> > +
> > +    len = s->ops->readlink(s->ops->opaque, path->data, buf->data, 1024 - 1);
> > +    if (len > -1) {
> > +	buf->size = len;
> > +	buf->data[len] = 0;
> > +    }
> > +
> > +    return len;
> > +}
> > +
> >  static void v9fs_string_free(V9fsString *str)
> >  {
> >      free(str->data);
> 
> Should be qemu_free, no?
> 


Updated the patch

-aneesh
jvrao - March 9, 2010, 2:08 a.m.
Aneesh Kumar K. V wrote:
> On Wed, 3 Mar 2010 23:35:36 +0300 (MSK), malc <av1474@comtv.ru> wrote:
>> On Wed, 3 Mar 2010, Anthony Liguori wrote:
>>
>>> This get the mount to work on the guest
>>>
>>> [kiran@linux.vnet.ibm.com: malloc to qemu_malloc conversion]
>>>
>>> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
>>> Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
>>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
>>> ---
>>>  hw/virtio-9p-local.c |    7 ++
>>>  hw/virtio-9p.c       |  169 +++++++++++++++++++++++++++++++++++++++++++++++++-
>>>  2 files changed, 174 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/hw/virtio-9p-local.c b/hw/virtio-9p-local.c
>>> index 204437c..9752f76 100644
>>> --- a/hw/virtio-9p-local.c
>>> +++ b/hw/virtio-9p-local.c
>>> @@ -72,9 +72,16 @@ static int local_setuid(void *opaque, uid_t uid)
>>>      return 0;
>>>  }
>>>  
>>> +static ssize_t local_readlink(void *opaque, const char *path,
>>> +			      char *buf, size_t bufsz)
>>> +{
>>> +    return readlink(rpath(path), buf, bufsz);
>>> +}
>>> +
>>>  static V9fsPosixFileOperations ops = {
>>>      .lstat = local_lstat,
>>>      .setuid = local_setuid,
>>> +    .readlink = local_readlink,
>>>  };
>>>  
>>>  V9fsPosixFileOperations *virtio_9p_init_local(const char *path)
>>> diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c
>>> index c63ac80..10bcd89 100644
>>> --- a/hw/virtio-9p.c
>>> +++ b/hw/virtio-9p.c
>>> @@ -102,6 +102,21 @@ static int posix_setuid(V9fsState *s, uid_t uid)
>>>      return s->ops->setuid(s->ops->opaque, uid);
>>>  }
>>>  
>>> +static ssize_t posix_readlink(V9fsState *s, V9fsString *path, V9fsString *buf)
>>> +{
>>> +    ssize_t len;
>>> +
>>> +    buf->data = qemu_malloc(1024);
>>> +
>>> +    len = s->ops->readlink(s->ops->opaque, path->data, buf->data, 1024 - 1);
>>> +    if (len > -1) {
>>> +	buf->size = len;
>>> +	buf->data[len] = 0;
>>> +    }
>>> +
>>> +    return len;
>>> +}
>>> +
>>>  static void v9fs_string_free(V9fsString *str)
>>>  {
>>>      free(str->data);
>> Should be qemu_free, no?
>>
> 
> 
> Updated the patch

Is  there any reason (other than being coding style) in using qemu_free() 
instead of free()? As per qem-malloc.c qemu_free() is nothing but free().

The reason I am asking is.. tracking string allocs become tricky 
if some of them were defined using qemu_alloc() and others are allocated through
sprintf().

Thanks,
JV


> 
> -aneesh
> 
>
Paul Brook - March 9, 2010, 12:30 p.m.
> Is  there any reason (other than being coding style) in using qemu_free()
> instead of free()? As per qem-malloc.c qemu_free() is nothing but free().

The whole point of qemu_{malloc,free} is to isolate code from the system 
implementation of malloc/free. It's entirely possible that future versions of 
qemu_malloc will use a different memory allocation strategy.
 
> The reason I am asking is.. tracking string allocs become tricky
> if some of them were defined using qemu_alloc() and others are allocated
>  through sprintf().

sprintf does not allocate memory.
If you mean strdup, then you shouldn't be using that (use qemu_strdup).

Paul
Aneesh Kumar K.V - March 9, 2010, 2:35 p.m.
On Tue, 9 Mar 2010 12:30:08 +0000, Paul Brook <paul@codesourcery.com> wrote:
> > Is  there any reason (other than being coding style) in using qemu_free()
> > instead of free()? As per qem-malloc.c qemu_free() is nothing but free().
> 
> The whole point of qemu_{malloc,free} is to isolate code from the system 
> implementation of malloc/free. It's entirely possible that future versions of 
> qemu_malloc will use a different memory allocation strategy.
> 
> > The reason I am asking is.. tracking string allocs become tricky
> > if some of them were defined using qemu_alloc() and others are allocated
> >  through sprintf().
> 
> sprintf does not allocate memory.
> If you mean strdup, then you shouldn't be using that (use qemu_strdup).

we have code that does

static void v9fs_string_sprintf(V9fsString *str, const char *fmt, ...)
{
    va_list ap;
    int err;

    v9fs_string_free(str);

    va_start(ap, fmt);
    err = vasprintf(&str->data, fmt, ap);
    BUG_ON(err == -1);
    va_end(ap);

    str->size = err;
}


I guess we should not be using vasprint. What alternatives are
available today ?

-aneesh
jvrao - March 9, 2010, 3:59 p.m.
Paul Brook wrote:
>> Is  there any reason (other than being coding style) in using qemu_free()
>> instead of free()? As per qem-malloc.c qemu_free() is nothing but free().
> 
> The whole point of qemu_{malloc,free} is to isolate code from the system 
> implementation of malloc/free. It's entirely possible that future versions of 
> qemu_malloc will use a different memory allocation strategy.
> 
>> The reason I am asking is.. tracking string allocs become tricky
>> if some of them were defined using qemu_alloc() and others are allocated
>>  through sprintf().
> 
> sprintf does not allocate memory.
> If you mean strdup, then you shouldn't be using that (use qemu_strdup).

Thanks for correcting Paul.. I was talking about vasprintf() .. not really the sprintf()
In any case.. right way to do it may be adding a new qemu_vasprintf() for and use it
along with qemu_free() Right?

Thanks,
JV

> 
> Paul
Paul Brook - March 11, 2010, 4:37 p.m.
> Paul Brook wrote:
> >> Is  there any reason (other than being coding style) in using
> >> qemu_free() instead of free()? As per qem-malloc.c qemu_free() is
> >> nothing but free().
> >
> > The whole point of qemu_{malloc,free} is to isolate code from the system
> > implementation of malloc/free. It's entirely possible that future
> > versions of qemu_malloc will use a different memory allocation strategy.
> >
> >> The reason I am asking is.. tracking string allocs become tricky
> >> if some of them were defined using qemu_alloc() and others are allocated
> >>  through sprintf().
> >
> > sprintf does not allocate memory.
> > If you mean strdup, then you shouldn't be using that (use qemu_strdup).
> 
> Thanks for correcting Paul.. I was talking about vasprintf() .. not really
>  the sprintf() In any case.. right way to do it may be adding a new
>  qemu_vasprintf() for and use it along with qemu_free() Right?

Something like that, yes.  Any use of [v]asprintf is incorrect.

Paul

Patch

diff --git a/hw/virtio-9p-local.c b/hw/virtio-9p-local.c
index 204437c..9752f76 100644
--- a/hw/virtio-9p-local.c
+++ b/hw/virtio-9p-local.c
@@ -72,9 +72,16 @@  static int local_setuid(void *opaque, uid_t uid)
     return 0;
 }
 
+static ssize_t local_readlink(void *opaque, const char *path,
+			      char *buf, size_t bufsz)
+{
+    return readlink(rpath(path), buf, bufsz);
+}
+
 static V9fsPosixFileOperations ops = {
     .lstat = local_lstat,
     .setuid = local_setuid,
+    .readlink = local_readlink,
 };
 
 V9fsPosixFileOperations *virtio_9p_init_local(const char *path)
diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c
index c63ac80..10bcd89 100644
--- a/hw/virtio-9p.c
+++ b/hw/virtio-9p.c
@@ -102,6 +102,21 @@  static int posix_setuid(V9fsState *s, uid_t uid)
     return s->ops->setuid(s->ops->opaque, uid);
 }
 
+static ssize_t posix_readlink(V9fsState *s, V9fsString *path, V9fsString *buf)
+{
+    ssize_t len;
+
+    buf->data = qemu_malloc(1024);
+
+    len = s->ops->readlink(s->ops->opaque, path->data, buf->data, 1024 - 1);
+    if (len > -1) {
+	buf->size = len;
+	buf->data[len] = 0;
+    }
+
+    return len;
+}
+
 static void v9fs_string_free(V9fsString *str)
 {
     free(str->data);
@@ -109,6 +124,11 @@  static void v9fs_string_free(V9fsString *str)
     str->size = 0;
 }
 
+static void v9fs_string_null(V9fsString *str)
+{
+    v9fs_string_free(str);
+}
+
 static void v9fs_string_sprintf(V9fsString *str, const char *fmt, ...)
 {
     va_list ap;
@@ -124,6 +144,11 @@  static void v9fs_string_sprintf(V9fsString *str, const char *fmt, ...)
     str->size = err;
 }
 
+static size_t v9fs_string_size(V9fsString *str)
+{
+    return str->size;
+}
+
 static V9fsFidState *lookup_fid(V9fsState *s, int32_t fid)
 {
     V9fsFidState *f;
@@ -436,6 +461,15 @@  static size_t pdu_marshal(V9fsPDU *pdu, size_t offset, const char *fmt, ...)
     return offset - old_offset;
 }
 
+static void v9fs_stat_free(V9fsStat *stat)
+{
+    v9fs_string_free(&stat->name);
+    v9fs_string_free(&stat->uid);
+    v9fs_string_free(&stat->gid);
+    v9fs_string_free(&stat->muid);
+    v9fs_string_free(&stat->extension);
+}
+
 static void complete_pdu(V9fsState *s, V9fsPDU *pdu, ssize_t len)
 {
     int8_t id = pdu->id + 1; /* Response */
@@ -474,6 +508,88 @@  static void complete_pdu(V9fsState *s, V9fsPDU *pdu, ssize_t len)
     free_pdu(s, pdu);
 }
 
+static uint32_t stat_to_v9mode(const struct stat *stbuf)
+{
+    uint32_t mode;
+
+    mode = stbuf->st_mode & 0777;
+    if (S_ISDIR(stbuf->st_mode))
+	mode |= P9_STAT_MODE_DIR;
+
+    if (dotu) {
+	if (S_ISLNK(stbuf->st_mode))
+	    mode |= P9_STAT_MODE_SYMLINK;
+	if (S_ISSOCK(stbuf->st_mode))
+	    mode |= P9_STAT_MODE_SOCKET;
+	if (S_ISFIFO(stbuf->st_mode))
+	    mode |= P9_STAT_MODE_NAMED_PIPE;
+	if (S_ISBLK(stbuf->st_mode) || S_ISCHR(stbuf->st_mode))
+	    mode |= P9_STAT_MODE_DEVICE;
+	if (stbuf->st_mode & S_ISUID)
+	    mode |= P9_STAT_MODE_SETUID;
+	if (stbuf->st_mode & S_ISGID)
+	    mode |= P9_STAT_MODE_SETGID;
+	if (stbuf->st_mode & S_ISVTX)
+	    mode |= P9_STAT_MODE_SETVTX;
+    }
+
+    return mode;
+}
+
+static void stat_to_v9stat(V9fsState *s, V9fsString *name,
+			   const struct stat *stbuf,
+			   V9fsStat *v9stat)
+{
+    int err;
+    const char *str;
+
+    memset(v9stat, 0, sizeof(*v9stat));
+
+    stat_to_qid(stbuf, &v9stat->qid);
+    v9stat->mode = stat_to_v9mode(stbuf);
+    v9stat->atime = stbuf->st_atime;
+    v9stat->mtime = stbuf->st_mtime;
+    v9stat->length = stbuf->st_size;
+
+    v9fs_string_null(&v9stat->uid);
+    v9fs_string_null(&v9stat->gid);
+    v9fs_string_null(&v9stat->muid);
+
+    if (dotu) {
+	v9stat->n_uid = stbuf->st_uid;
+	v9stat->n_gid = stbuf->st_gid;
+	v9stat->n_muid = 0;
+
+	v9fs_string_null(&v9stat->extension);
+
+	if (v9stat->mode & P9_STAT_MODE_SYMLINK) {
+	    err = posix_readlink(s, name, &v9stat->extension);
+	    BUG_ON(err == -1);
+	    v9stat->extension.data[err] = 0;
+	    v9stat->extension.size = err;
+	} else if (v9stat->mode & P9_STAT_MODE_DEVICE) {
+	    v9fs_string_sprintf(&v9stat->extension, "%c %u %u",
+				S_ISCHR(stbuf->st_mode) ? 'c' : 'b',
+				major(stbuf->st_rdev), minor(stbuf->st_rdev));
+	}
+    }
+
+    str = strrchr(name->data, '/');
+    if (str)
+	str += 1;
+    else
+	str = name->data;
+
+    v9fs_string_sprintf(&v9stat->name, "%s", str);
+
+    v9stat->size = 61 +
+	v9fs_string_size(&v9stat->name) +
+	v9fs_string_size(&v9stat->uid) +
+	v9fs_string_size(&v9stat->gid) +
+	v9fs_string_size(&v9stat->muid) +
+	v9fs_string_size(&v9stat->extension);
+}
+
 static void v9fs_version(V9fsState *s, V9fsPDU *pdu)
 {
     int32_t msize;
@@ -520,10 +636,59 @@  out:
     v9fs_string_free(&aname);
 }
 
+typedef struct V9fsStatState {
+    V9fsPDU *pdu;
+    size_t offset;
+    int32_t fid;
+    V9fsStat v9stat;
+    V9fsFidState *fidp;
+    struct stat stbuf;
+} V9fsStatState;
+
+static void v9fs_stat_post_lstat(V9fsState *s, V9fsStatState *vs, int err)
+{
+    if (err == -1) {
+        err = -errno;
+        goto out;
+    }
+
+    stat_to_v9stat(s, &vs->fidp->path, &vs->stbuf, &vs->v9stat);
+    vs->offset += pdu_marshal(vs->pdu, vs->offset, "wS", 0, &vs->v9stat);
+    err = vs->offset;
+
+out:
+    complete_pdu(s, vs->pdu, err);
+    v9fs_stat_free(&vs->v9stat);
+    qemu_free(vs);
+}
+
 static void v9fs_stat(V9fsState *s, V9fsPDU *pdu)
 {
-    if (debug_9p_pdu)
-	pprint_pdu(pdu);
+    V9fsStatState *vs;
+    ssize_t err = 0;
+
+    vs = qemu_malloc(sizeof(*vs));
+    vs->pdu = pdu;
+    vs->offset = 7;
+
+    memset(&vs->v9stat, 0, sizeof(vs->v9stat));
+
+    pdu_unmarshal(vs->pdu, vs->offset, "d", &vs->fid);
+
+    vs->fidp = lookup_fid(s, vs->fid);
+    if (vs->fidp == NULL) {
+	    err = -ENOENT;
+        goto out;
+    }
+
+    err = posix_lstat(s, &vs->fidp->path, &vs->stbuf);
+    v9fs_stat_post_lstat(s, vs, err);
+    return;
+
+out:
+    complete_pdu(s, vs->pdu, err);
+    v9fs_stat_free(&vs->v9stat);
+    qemu_free(vs);
 }
 
 static void v9fs_walk(V9fsState *s, V9fsPDU *pdu)