* [Qemu-devel] [PATCH] [RESEND-try-3] hw/9pfs: fix P9_STATS_GEN handling
@ 2014-01-28 10:55 Kirill A. Shutemov
2014-01-28 11:15 ` Paolo Bonzini
2014-01-28 11:26 ` Michael S. Tsirkin
0 siblings, 2 replies; 6+ messages in thread
From: Kirill A. Shutemov @ 2014-01-28 10:55 UTC (permalink / raw)
To: qemu-devel, aliguori; +Cc: aneesh.kumar, Kirill A. Shutemov, armbru
Currently we have few issues with P9_STATS_GEN:
- We don't try to read st_gen anything except files or directories, but
still set P9_STATS_GEN bit in st_result_mask. It may mislead client:
we present garbage as valid st_gen.
- If we failed to get valid st_gen with ENOTTY, we ignore error, but
still set P9_STATS_GEN bit in st_result_mask.
- If we failed to get valid st_gen with any other errno, we fail
getattr altogether. It's excessive: we block valid client use-cases,
like chdir(2) to non-readable directory with execution bit set.
The patch fixes these issues and cleanup code a bit.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
hw/9pfs/cofile.c | 4 ----
hw/9pfs/virtio-9p-handle.c | 8 +++++++-
hw/9pfs/virtio-9p-local.c | 10 ++++++----
hw/9pfs/virtio-9p-proxy.c | 3 ++-
hw/9pfs/virtio-9p.c | 12 ++++++++++--
5 files changed, 25 insertions(+), 12 deletions(-)
diff --git a/hw/9pfs/cofile.c b/hw/9pfs/cofile.c
index 194c1306c665..2efebf35710f 100644
--- a/hw/9pfs/cofile.c
+++ b/hw/9pfs/cofile.c
@@ -38,10 +38,6 @@ int v9fs_co_st_gen(V9fsPDU *pdu, V9fsPath *path, mode_t st_mode,
});
v9fs_path_unlock(s);
}
- /* The ioctl may not be supported depending on the path */
- if (err == -ENOTTY) {
- err = 0;
- }
return err;
}
diff --git a/hw/9pfs/virtio-9p-handle.c b/hw/9pfs/virtio-9p-handle.c
index fe8e0ed19dcc..17002a3d2867 100644
--- a/hw/9pfs/virtio-9p-handle.c
+++ b/hw/9pfs/virtio-9p-handle.c
@@ -582,6 +582,7 @@ static int handle_unlinkat(FsContext *ctx, V9fsPath *dir,
static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path,
mode_t st_mode, uint64_t *st_gen)
{
+#ifdef FS_IOC_GETVERSION
int err;
V9fsFidOpenState fid_open;
@@ -590,7 +591,8 @@ static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path,
* We can get fd for regular files and directories only
*/
if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
- return 0;
+ errno = ENOTTY;
+ return -1;
}
err = handle_open(ctx, path, O_RDONLY, &fid_open);
if (err < 0) {
@@ -599,6 +601,10 @@ static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path,
err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
handle_close(ctx, &fid_open);
return err;
+#else
+ errno = ENOTTY;
+ return -1;
+#endif
}
static int handle_init(FsContext *ctx)
diff --git a/hw/9pfs/virtio-9p-local.c b/hw/9pfs/virtio-9p-local.c
index fc93e9e6e8da..df0dbffa7ac4 100644
--- a/hw/9pfs/virtio-9p-local.c
+++ b/hw/9pfs/virtio-9p-local.c
@@ -1068,8 +1068,8 @@ err_out:
static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
mode_t st_mode, uint64_t *st_gen)
{
- int err;
#ifdef FS_IOC_GETVERSION
+ int err;
V9fsFidOpenState fid_open;
/*
@@ -1077,7 +1077,8 @@ static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
* We can get fd for regular files and directories only
*/
if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
- return 0;
+ errno = ENOTTY;
+ return -1;
}
err = local_open(ctx, path, O_RDONLY, &fid_open);
if (err < 0) {
@@ -1085,10 +1086,11 @@ static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
}
err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
local_close(ctx, &fid_open);
+ return err;
#else
- err = -ENOTTY;
+ errno = ENOTTY;
+ return -1;
#endif
- return err;
}
static int local_init(FsContext *ctx)
diff --git a/hw/9pfs/virtio-9p-proxy.c b/hw/9pfs/virtio-9p-proxy.c
index 5f44bb758b35..b57966d9d883 100644
--- a/hw/9pfs/virtio-9p-proxy.c
+++ b/hw/9pfs/virtio-9p-proxy.c
@@ -1086,7 +1086,8 @@ static int proxy_ioc_getversion(FsContext *fs_ctx, V9fsPath *path,
* we can get fd for regular files and directories only
*/
if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
- return 0;
+ errno = ENOTTY;
+ return -1;
}
err = v9fs_request(fs_ctx->private, T_GETVERSION, st_gen, "s", path);
if (err < 0) {
diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
index 8cbb8ae32a03..3e51fcd152f8 100644
--- a/hw/9pfs/virtio-9p.c
+++ b/hw/9pfs/virtio-9p.c
@@ -1080,10 +1080,18 @@ static void v9fs_getattr(void *opaque)
/* fill st_gen if requested and supported by underlying fs */
if (request_mask & P9_STATS_GEN) {
retval = v9fs_co_st_gen(pdu, &fidp->path, stbuf.st_mode, &v9stat_dotl);
- if (retval < 0) {
+ switch (retval) {
+ case 0:
+ /* we have valid st_gen: update result mask */
+ v9stat_dotl.st_result_mask |= P9_STATS_GEN;
+ break;
+ case -EINTR:
+ /* request cancelled */
goto out;
+ default:
+ /* failed to get st_gen: not fatal, ignore */
+ break;
}
- v9stat_dotl.st_result_mask |= P9_STATS_GEN;
}
retval = pdu_marshal(pdu, offset, "A", &v9stat_dotl);
if (retval < 0) {
--
1.8.5.2
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] [RESEND-try-3] hw/9pfs: fix P9_STATS_GEN handling
2014-01-28 10:55 [Qemu-devel] [PATCH] [RESEND-try-3] hw/9pfs: fix P9_STATS_GEN handling Kirill A. Shutemov
@ 2014-01-28 11:15 ` Paolo Bonzini
2014-01-28 12:31 ` Aneesh Kumar K.V
2014-01-28 11:26 ` Michael S. Tsirkin
1 sibling, 1 reply; 6+ messages in thread
From: Paolo Bonzini @ 2014-01-28 11:15 UTC (permalink / raw)
To: Kirill A. Shutemov, qemu-devel, aliguori
Cc: Michael S. Tsirkin, aneesh.kumar, armbru
Il 28/01/2014 11:55, Kirill A. Shutemov ha scritto:
> Currently we have few issues with P9_STATS_GEN:
>
> - We don't try to read st_gen anything except files or directories, but
> still set P9_STATS_GEN bit in st_result_mask. It may mislead client:
> we present garbage as valid st_gen.
>
> - If we failed to get valid st_gen with ENOTTY, we ignore error, but
> still set P9_STATS_GEN bit in st_result_mask.
>
> - If we failed to get valid st_gen with any other errno, we fail
> getattr altogether. It's excessive: we block valid client use-cases,
> like chdir(2) to non-readable directory with execution bit set.
>
> The patch fixes these issues and cleanup code a bit.
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
> hw/9pfs/cofile.c | 4 ----
> hw/9pfs/virtio-9p-handle.c | 8 +++++++-
> hw/9pfs/virtio-9p-local.c | 10 ++++++----
> hw/9pfs/virtio-9p-proxy.c | 3 ++-
> hw/9pfs/virtio-9p.c | 12 ++++++++++--
> 5 files changed, 25 insertions(+), 12 deletions(-)
>
> diff --git a/hw/9pfs/cofile.c b/hw/9pfs/cofile.c
> index 194c1306c665..2efebf35710f 100644
> --- a/hw/9pfs/cofile.c
> +++ b/hw/9pfs/cofile.c
> @@ -38,10 +38,6 @@ int v9fs_co_st_gen(V9fsPDU *pdu, V9fsPath *path, mode_t st_mode,
> });
> v9fs_path_unlock(s);
> }
> - /* The ioctl may not be supported depending on the path */
> - if (err == -ENOTTY) {
> - err = 0;
> - }
> return err;
> }
>
> diff --git a/hw/9pfs/virtio-9p-handle.c b/hw/9pfs/virtio-9p-handle.c
> index fe8e0ed19dcc..17002a3d2867 100644
> --- a/hw/9pfs/virtio-9p-handle.c
> +++ b/hw/9pfs/virtio-9p-handle.c
> @@ -582,6 +582,7 @@ static int handle_unlinkat(FsContext *ctx, V9fsPath *dir,
> static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path,
> mode_t st_mode, uint64_t *st_gen)
> {
> +#ifdef FS_IOC_GETVERSION
> int err;
> V9fsFidOpenState fid_open;
>
> @@ -590,7 +591,8 @@ static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path,
> * We can get fd for regular files and directories only
> */
> if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
> - return 0;
> + errno = ENOTTY;
> + return -1;
> }
> err = handle_open(ctx, path, O_RDONLY, &fid_open);
> if (err < 0) {
> @@ -599,6 +601,10 @@ static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path,
> err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
> handle_close(ctx, &fid_open);
> return err;
> +#else
> + errno = ENOTTY;
> + return -1;
> +#endif
> }
>
> static int handle_init(FsContext *ctx)
> diff --git a/hw/9pfs/virtio-9p-local.c b/hw/9pfs/virtio-9p-local.c
> index fc93e9e6e8da..df0dbffa7ac4 100644
> --- a/hw/9pfs/virtio-9p-local.c
> +++ b/hw/9pfs/virtio-9p-local.c
> @@ -1068,8 +1068,8 @@ err_out:
> static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
> mode_t st_mode, uint64_t *st_gen)
> {
> - int err;
> #ifdef FS_IOC_GETVERSION
> + int err;
> V9fsFidOpenState fid_open;
>
> /*
> @@ -1077,7 +1077,8 @@ static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
> * We can get fd for regular files and directories only
> */
> if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
> - return 0;
> + errno = ENOTTY;
> + return -1;
> }
> err = local_open(ctx, path, O_RDONLY, &fid_open);
> if (err < 0) {
> @@ -1085,10 +1086,11 @@ static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
> }
> err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
> local_close(ctx, &fid_open);
> + return err;
> #else
> - err = -ENOTTY;
> + errno = ENOTTY;
> + return -1;
> #endif
> - return err;
> }
>
> static int local_init(FsContext *ctx)
> diff --git a/hw/9pfs/virtio-9p-proxy.c b/hw/9pfs/virtio-9p-proxy.c
> index 5f44bb758b35..b57966d9d883 100644
> --- a/hw/9pfs/virtio-9p-proxy.c
> +++ b/hw/9pfs/virtio-9p-proxy.c
> @@ -1086,7 +1086,8 @@ static int proxy_ioc_getversion(FsContext *fs_ctx, V9fsPath *path,
> * we can get fd for regular files and directories only
> */
> if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
> - return 0;
> + errno = ENOTTY;
> + return -1;
> }
> err = v9fs_request(fs_ctx->private, T_GETVERSION, st_gen, "s", path);
> if (err < 0) {
> diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
> index 8cbb8ae32a03..3e51fcd152f8 100644
> --- a/hw/9pfs/virtio-9p.c
> +++ b/hw/9pfs/virtio-9p.c
> @@ -1080,10 +1080,18 @@ static void v9fs_getattr(void *opaque)
> /* fill st_gen if requested and supported by underlying fs */
> if (request_mask & P9_STATS_GEN) {
> retval = v9fs_co_st_gen(pdu, &fidp->path, stbuf.st_mode, &v9stat_dotl);
> - if (retval < 0) {
> + switch (retval) {
> + case 0:
> + /* we have valid st_gen: update result mask */
> + v9stat_dotl.st_result_mask |= P9_STATS_GEN;
> + break;
> + case -EINTR:
> + /* request cancelled */
> goto out;
> + default:
> + /* failed to get st_gen: not fatal, ignore */
> + break;
> }
> - v9stat_dotl.st_result_mask |= P9_STATS_GEN;
> }
> retval = pdu_marshal(pdu, offset, "A", &v9stat_dotl);
> if (retval < 0) {
>
Michael, are you going to take this patch given that the virtio-9p
maintainer is AWOL?
Paolo
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] [RESEND-try-3] hw/9pfs: fix P9_STATS_GEN handling
2014-01-28 10:55 [Qemu-devel] [PATCH] [RESEND-try-3] hw/9pfs: fix P9_STATS_GEN handling Kirill A. Shutemov
2014-01-28 11:15 ` Paolo Bonzini
@ 2014-01-28 11:26 ` Michael S. Tsirkin
2014-01-28 11:40 ` Kirill A. Shutemov
1 sibling, 1 reply; 6+ messages in thread
From: Michael S. Tsirkin @ 2014-01-28 11:26 UTC (permalink / raw)
To: Kirill A. Shutemov; +Cc: armbru, qemu-devel, aliguori, aneesh.kumar
On Tue, Jan 28, 2014 at 12:55:51PM +0200, Kirill A. Shutemov wrote:
> Currently we have few issues with P9_STATS_GEN:
>
> - We don't try to read st_gen anything except files or directories, but
> still set P9_STATS_GEN bit in st_result_mask. It may mislead client:
> we present garbage as valid st_gen.
>
> - If we failed to get valid st_gen with ENOTTY, we ignore error, but
> still set P9_STATS_GEN bit in st_result_mask.
>
> - If we failed to get valid st_gen with any other errno, we fail
> getattr altogether. It's excessive: we block valid client use-cases,
> like chdir(2) to non-readable directory with execution bit set.
>
> The patch fixes these issues and cleanup code a bit.
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Would be better to split unrelated issues out to separate patches.
> ---
> hw/9pfs/cofile.c | 4 ----
> hw/9pfs/virtio-9p-handle.c | 8 +++++++-
> hw/9pfs/virtio-9p-local.c | 10 ++++++----
> hw/9pfs/virtio-9p-proxy.c | 3 ++-
> hw/9pfs/virtio-9p.c | 12 ++++++++++--
> 5 files changed, 25 insertions(+), 12 deletions(-)
>
> diff --git a/hw/9pfs/cofile.c b/hw/9pfs/cofile.c
> index 194c1306c665..2efebf35710f 100644
> --- a/hw/9pfs/cofile.c
> +++ b/hw/9pfs/cofile.c
> @@ -38,10 +38,6 @@ int v9fs_co_st_gen(V9fsPDU *pdu, V9fsPath *path, mode_t st_mode,
> });
> v9fs_path_unlock(s);
> }
> - /* The ioctl may not be supported depending on the path */
> - if (err == -ENOTTY) {
> - err = 0;
> - }
> return err;
> }
>
> diff --git a/hw/9pfs/virtio-9p-handle.c b/hw/9pfs/virtio-9p-handle.c
> index fe8e0ed19dcc..17002a3d2867 100644
> --- a/hw/9pfs/virtio-9p-handle.c
> +++ b/hw/9pfs/virtio-9p-handle.c
> @@ -582,6 +582,7 @@ static int handle_unlinkat(FsContext *ctx, V9fsPath *dir,
> static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path,
> mode_t st_mode, uint64_t *st_gen)
> {
> +#ifdef FS_IOC_GETVERSION
> int err;
> V9fsFidOpenState fid_open;
>
> @@ -590,7 +591,8 @@ static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path,
> * We can get fd for regular files and directories only
> */
> if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
> - return 0;
> + errno = ENOTTY;
> + return -1;
> }
> err = handle_open(ctx, path, O_RDONLY, &fid_open);
> if (err < 0) {
> @@ -599,6 +601,10 @@ static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path,
> err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
> handle_close(ctx, &fid_open);
> return err;
> +#else
> + errno = ENOTTY;
> + return -1;
> +#endif
> }
>
> static int handle_init(FsContext *ctx)
> diff --git a/hw/9pfs/virtio-9p-local.c b/hw/9pfs/virtio-9p-local.c
> index fc93e9e6e8da..df0dbffa7ac4 100644
> --- a/hw/9pfs/virtio-9p-local.c
> +++ b/hw/9pfs/virtio-9p-local.c
> @@ -1068,8 +1068,8 @@ err_out:
> static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
> mode_t st_mode, uint64_t *st_gen)
> {
> - int err;
> #ifdef FS_IOC_GETVERSION
> + int err;
> V9fsFidOpenState fid_open;
>
> /*
> @@ -1077,7 +1077,8 @@ static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
> * We can get fd for regular files and directories only
> */
> if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
> - return 0;
> + errno = ENOTTY;
> + return -1;
> }
> err = local_open(ctx, path, O_RDONLY, &fid_open);
> if (err < 0) {
> @@ -1085,10 +1086,11 @@ static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
> }
> err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
> local_close(ctx, &fid_open);
> + return err;
> #else
> - err = -ENOTTY;
> + errno = ENOTTY;
> + return -1;
> #endif
> - return err;
> }
>
> static int local_init(FsContext *ctx)
> diff --git a/hw/9pfs/virtio-9p-proxy.c b/hw/9pfs/virtio-9p-proxy.c
> index 5f44bb758b35..b57966d9d883 100644
> --- a/hw/9pfs/virtio-9p-proxy.c
> +++ b/hw/9pfs/virtio-9p-proxy.c
> @@ -1086,7 +1086,8 @@ static int proxy_ioc_getversion(FsContext *fs_ctx, V9fsPath *path,
> * we can get fd for regular files and directories only
> */
> if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
> - return 0;
> + errno = ENOTTY;
> + return -1;
> }
> err = v9fs_request(fs_ctx->private, T_GETVERSION, st_gen, "s", path);
> if (err < 0) {
> diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
> index 8cbb8ae32a03..3e51fcd152f8 100644
> --- a/hw/9pfs/virtio-9p.c
> +++ b/hw/9pfs/virtio-9p.c
> @@ -1080,10 +1080,18 @@ static void v9fs_getattr(void *opaque)
> /* fill st_gen if requested and supported by underlying fs */
> if (request_mask & P9_STATS_GEN) {
> retval = v9fs_co_st_gen(pdu, &fidp->path, stbuf.st_mode, &v9stat_dotl);
> - if (retval < 0) {
> + switch (retval) {
> + case 0:
> + /* we have valid st_gen: update result mask */
> + v9stat_dotl.st_result_mask |= P9_STATS_GEN;
> + break;
> + case -EINTR:
> + /* request cancelled */
> goto out;
Shouldn't EINTR be retried?
> + default:
> + /* failed to get st_gen: not fatal, ignore */
> + break;
> }
> - v9stat_dotl.st_result_mask |= P9_STATS_GEN;
> }
> retval = pdu_marshal(pdu, offset, "A", &v9stat_dotl);
> if (retval < 0) {
> --
> 1.8.5.2
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] [RESEND-try-3] hw/9pfs: fix P9_STATS_GEN handling
2014-01-28 11:26 ` Michael S. Tsirkin
@ 2014-01-28 11:40 ` Kirill A. Shutemov
2014-01-28 12:09 ` Michael S. Tsirkin
0 siblings, 1 reply; 6+ messages in thread
From: Kirill A. Shutemov @ 2014-01-28 11:40 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: aneesh.kumar, armbru, qemu-devel, Kirill A. Shutemov, aliguori
Michael S. Tsirkin wrote:
> On Tue, Jan 28, 2014 at 12:55:51PM +0200, Kirill A. Shutemov wrote:
> > Currently we have few issues with P9_STATS_GEN:
> >
> > - We don't try to read st_gen anything except files or directories, but
> > still set P9_STATS_GEN bit in st_result_mask. It may mislead client:
> > we present garbage as valid st_gen.
> >
> > - If we failed to get valid st_gen with ENOTTY, we ignore error, but
> > still set P9_STATS_GEN bit in st_result_mask.
> >
> > - If we failed to get valid st_gen with any other errno, we fail
> > getattr altogether. It's excessive: we block valid client use-cases,
> > like chdir(2) to non-readable directory with execution bit set.
> >
> > The patch fixes these issues and cleanup code a bit.
> >
> > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> > Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
> > Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
>
> Would be better to split unrelated issues out to separate patches.
They are not totally unrelated: they all unbreak P9_STATS_GEN.
But yes, I can split if it needed.
> > diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
> > index 8cbb8ae32a03..3e51fcd152f8 100644
> > --- a/hw/9pfs/virtio-9p.c
> > +++ b/hw/9pfs/virtio-9p.c
> > @@ -1080,10 +1080,18 @@ static void v9fs_getattr(void *opaque)
> > /* fill st_gen if requested and supported by underlying fs */
> > if (request_mask & P9_STATS_GEN) {
> > retval = v9fs_co_st_gen(pdu, &fidp->path, stbuf.st_mode, &v9stat_dotl);
> > - if (retval < 0) {
> > + switch (retval) {
> > + case 0:
> > + /* we have valid st_gen: update result mask */
> > + v9stat_dotl.st_result_mask |= P9_STATS_GEN;
> > + break;
> > + case -EINTR:
> > + /* request cancelled */
> > goto out;
>
> Shouldn't EINTR be retried?
No. It could be canceled by client (with Tflush) on purpose and client can
retry if needed.
--
Kirill A. Shutemov
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] [RESEND-try-3] hw/9pfs: fix P9_STATS_GEN handling
2014-01-28 11:40 ` Kirill A. Shutemov
@ 2014-01-28 12:09 ` Michael S. Tsirkin
0 siblings, 0 replies; 6+ messages in thread
From: Michael S. Tsirkin @ 2014-01-28 12:09 UTC (permalink / raw)
To: Kirill A. Shutemov; +Cc: armbru, qemu-devel, aliguori, aneesh.kumar
On Tue, Jan 28, 2014 at 01:40:59PM +0200, Kirill A. Shutemov wrote:
> Michael S. Tsirkin wrote:
> > On Tue, Jan 28, 2014 at 12:55:51PM +0200, Kirill A. Shutemov wrote:
> > > Currently we have few issues with P9_STATS_GEN:
> > >
> > > - We don't try to read st_gen anything except files or directories, but
> > > still set P9_STATS_GEN bit in st_result_mask. It may mislead client:
> > > we present garbage as valid st_gen.
> > >
> > > - If we failed to get valid st_gen with ENOTTY, we ignore error, but
> > > still set P9_STATS_GEN bit in st_result_mask.
> > >
> > > - If we failed to get valid st_gen with any other errno, we fail
> > > getattr altogether. It's excessive: we block valid client use-cases,
> > > like chdir(2) to non-readable directory with execution bit set.
> > >
> > > The patch fixes these issues and cleanup code a bit.
> > >
> > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> > > Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
> > > Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> >
> > Would be better to split unrelated issues out to separate patches.
>
> They are not totally unrelated: they all unbreak P9_STATS_GEN.
>
> But yes, I can split if it needed.
Probably a good idea.
If you can append explanation on how to reproduce the bug
that's fixed for each patch, even better.
> > > diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
> > > index 8cbb8ae32a03..3e51fcd152f8 100644
> > > --- a/hw/9pfs/virtio-9p.c
> > > +++ b/hw/9pfs/virtio-9p.c
> > > @@ -1080,10 +1080,18 @@ static void v9fs_getattr(void *opaque)
> > > /* fill st_gen if requested and supported by underlying fs */
> > > if (request_mask & P9_STATS_GEN) {
> > > retval = v9fs_co_st_gen(pdu, &fidp->path, stbuf.st_mode, &v9stat_dotl);
> > > - if (retval < 0) {
> > > + switch (retval) {
> > > + case 0:
> > > + /* we have valid st_gen: update result mask */
> > > + v9stat_dotl.st_result_mask |= P9_STATS_GEN;
> > > + break;
> > > + case -EINTR:
> > > + /* request cancelled */
> > > goto out;
> >
> > Shouldn't EINTR be retried?
>
> No. It could be canceled by client (with Tflush) on purpose and client can
> retry if needed.
>
> --
> Kirill A. Shutemov
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] [RESEND-try-3] hw/9pfs: fix P9_STATS_GEN handling
2014-01-28 11:15 ` Paolo Bonzini
@ 2014-01-28 12:31 ` Aneesh Kumar K.V
0 siblings, 0 replies; 6+ messages in thread
From: Aneesh Kumar K.V @ 2014-01-28 12:31 UTC (permalink / raw)
To: Paolo Bonzini, Kirill A. Shutemov, qemu-devel, aliguori
Cc: armbru, Michael S. Tsirkin
Paolo Bonzini <pbonzini@redhat.com> writes:
> Il 28/01/2014 11:55, Kirill A. Shutemov ha scritto:
>> Currently we have few issues with P9_STATS_GEN:
>>
>> - We don't try to read st_gen anything except files or directories, but
>> still set P9_STATS_GEN bit in st_result_mask. It may mislead client:
>> we present garbage as valid st_gen.
>>
>> - If we failed to get valid st_gen with ENOTTY, we ignore error, but
>> still set P9_STATS_GEN bit in st_result_mask.
>>
>> - If we failed to get valid st_gen with any other errno, we fail
>> getattr altogether. It's excessive: we block valid client use-cases,
>> like chdir(2) to non-readable directory with execution bit set.
>>
>> The patch fixes these issues and cleanup code a bit.
>>
>> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
>> Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
>> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
>> ---
>> hw/9pfs/cofile.c | 4 ----
>> hw/9pfs/virtio-9p-handle.c | 8 +++++++-
>> hw/9pfs/virtio-9p-local.c | 10 ++++++----
>> hw/9pfs/virtio-9p-proxy.c | 3 ++-
>> hw/9pfs/virtio-9p.c | 12 ++++++++++--
>> 5 files changed, 25 insertions(+), 12 deletions(-)
>>
>> diff --git a/hw/9pfs/cofile.c b/hw/9pfs/cofile.c
>> index 194c1306c665..2efebf35710f 100644
>> --- a/hw/9pfs/cofile.c
>> +++ b/hw/9pfs/cofile.c
>> @@ -38,10 +38,6 @@ int v9fs_co_st_gen(V9fsPDU *pdu, V9fsPath *path, mode_t st_mode,
>> });
>> v9fs_path_unlock(s);
>> }
>> - /* The ioctl may not be supported depending on the path */
>> - if (err == -ENOTTY) {
>> - err = 0;
>> - }
>> return err;
>> }
>>
>> diff --git a/hw/9pfs/virtio-9p-handle.c b/hw/9pfs/virtio-9p-handle.c
>> index fe8e0ed19dcc..17002a3d2867 100644
>> --- a/hw/9pfs/virtio-9p-handle.c
>> +++ b/hw/9pfs/virtio-9p-handle.c
>> @@ -582,6 +582,7 @@ static int handle_unlinkat(FsContext *ctx, V9fsPath *dir,
>> static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path,
>> mode_t st_mode, uint64_t *st_gen)
>> {
>> +#ifdef FS_IOC_GETVERSION
>> int err;
>> V9fsFidOpenState fid_open;
>>
>> @@ -590,7 +591,8 @@ static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path,
>> * We can get fd for regular files and directories only
>> */
>> if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
>> - return 0;
>> + errno = ENOTTY;
>> + return -1;
>> }
>> err = handle_open(ctx, path, O_RDONLY, &fid_open);
>> if (err < 0) {
>> @@ -599,6 +601,10 @@ static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path,
>> err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
>> handle_close(ctx, &fid_open);
>> return err;
>> +#else
>> + errno = ENOTTY;
>> + return -1;
>> +#endif
>> }
>>
>> static int handle_init(FsContext *ctx)
>> diff --git a/hw/9pfs/virtio-9p-local.c b/hw/9pfs/virtio-9p-local.c
>> index fc93e9e6e8da..df0dbffa7ac4 100644
>> --- a/hw/9pfs/virtio-9p-local.c
>> +++ b/hw/9pfs/virtio-9p-local.c
>> @@ -1068,8 +1068,8 @@ err_out:
>> static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
>> mode_t st_mode, uint64_t *st_gen)
>> {
>> - int err;
>> #ifdef FS_IOC_GETVERSION
>> + int err;
>> V9fsFidOpenState fid_open;
>>
>> /*
>> @@ -1077,7 +1077,8 @@ static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
>> * We can get fd for regular files and directories only
>> */
>> if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
>> - return 0;
>> + errno = ENOTTY;
>> + return -1;
>> }
>> err = local_open(ctx, path, O_RDONLY, &fid_open);
>> if (err < 0) {
>> @@ -1085,10 +1086,11 @@ static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
>> }
>> err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
>> local_close(ctx, &fid_open);
>> + return err;
>> #else
>> - err = -ENOTTY;
>> + errno = ENOTTY;
>> + return -1;
>> #endif
>> - return err;
>> }
>>
>> static int local_init(FsContext *ctx)
>> diff --git a/hw/9pfs/virtio-9p-proxy.c b/hw/9pfs/virtio-9p-proxy.c
>> index 5f44bb758b35..b57966d9d883 100644
>> --- a/hw/9pfs/virtio-9p-proxy.c
>> +++ b/hw/9pfs/virtio-9p-proxy.c
>> @@ -1086,7 +1086,8 @@ static int proxy_ioc_getversion(FsContext *fs_ctx, V9fsPath *path,
>> * we can get fd for regular files and directories only
>> */
>> if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
>> - return 0;
>> + errno = ENOTTY;
>> + return -1;
>> }
>> err = v9fs_request(fs_ctx->private, T_GETVERSION, st_gen, "s", path);
>> if (err < 0) {
>> diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
>> index 8cbb8ae32a03..3e51fcd152f8 100644
>> --- a/hw/9pfs/virtio-9p.c
>> +++ b/hw/9pfs/virtio-9p.c
>> @@ -1080,10 +1080,18 @@ static void v9fs_getattr(void *opaque)
>> /* fill st_gen if requested and supported by underlying fs */
>> if (request_mask & P9_STATS_GEN) {
>> retval = v9fs_co_st_gen(pdu, &fidp->path, stbuf.st_mode, &v9stat_dotl);
>> - if (retval < 0) {
>> + switch (retval) {
>> + case 0:
>> + /* we have valid st_gen: update result mask */
>> + v9stat_dotl.st_result_mask |= P9_STATS_GEN;
>> + break;
>> + case -EINTR:
>> + /* request cancelled */
>> goto out;
>> + default:
>> + /* failed to get st_gen: not fatal, ignore */
>> + break;
>> }
>> - v9stat_dotl.st_result_mask |= P9_STATS_GEN;
>> }
>> retval = pdu_marshal(pdu, offset, "A", &v9stat_dotl);
>> if (retval < 0) {
>>
>
> Michael, are you going to take this patch given that the virtio-9p
> maintainer is AWOL?
I did review the patch, and also specifically asked if we need a pull
request with this just one patch or can it be taken directly to upstream
tree. I was not sure whether generating a pull request with just one
patch was useful.
-aneesh
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2014-01-28 12:31 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2014-01-28 10:55 [Qemu-devel] [PATCH] [RESEND-try-3] hw/9pfs: fix P9_STATS_GEN handling Kirill A. Shutemov
2014-01-28 11:15 ` Paolo Bonzini
2014-01-28 12:31 ` Aneesh Kumar K.V
2014-01-28 11:26 ` Michael S. Tsirkin
2014-01-28 11:40 ` Kirill A. Shutemov
2014-01-28 12:09 ` Michael S. Tsirkin
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