[dpdk-dev,v5,1/4] vhost: eventfd_link: refactoring EVENTFD_COPY handler
Commit Message
* Move ioctl `EVENTFD_COPY' code to a separate function
* Remove extra #includes
* Introduce function fget_from_files
* Fix ioctl return values
Signed-off-by: Pavel Boldin <pboldin@mirantis.com>
---
lib/librte_vhost/eventfd_link/eventfd_link.c | 188 +++++++++++++++------------
1 file changed, 103 insertions(+), 85 deletions(-)
Comments
Ping.
On Fri, Aug 28, 2015 at 9:51 PM, Pavel Boldin <pboldin@mirantis.com> wrote:
> * Move ioctl `EVENTFD_COPY' code to a separate function
> * Remove extra #includes
> * Introduce function fget_from_files
> * Fix ioctl return values
>
> Signed-off-by: Pavel Boldin <pboldin@mirantis.com>
> ---
> lib/librte_vhost/eventfd_link/eventfd_link.c | 188
> +++++++++++++++------------
> 1 file changed, 103 insertions(+), 85 deletions(-)
>
> diff --git a/lib/librte_vhost/eventfd_link/eventfd_link.c
> b/lib/librte_vhost/eventfd_link/eventfd_link.c
> index 62c45c8..5ba1068 100644
> --- a/lib/librte_vhost/eventfd_link/eventfd_link.c
> +++ b/lib/librte_vhost/eventfd_link/eventfd_link.c
> @@ -22,18 +22,11 @@
> * Intel Corporation
> */
>
> -#include <linux/eventfd.h>
> #include <linux/miscdevice.h>
> #include <linux/module.h>
> -#include <linux/moduleparam.h>
> -#include <linux/rcupdate.h>
> #include <linux/file.h>
> -#include <linux/slab.h>
> -#include <linux/fs.h>
> -#include <linux/mmu_context.h>
> -#include <linux/sched.h>
> -#include <asm/mmu_context.h>
> #include <linux/fdtable.h>
> +#include <linux/syscalls.h>
>
> #include "eventfd_link.h"
>
> @@ -65,9 +58,26 @@ put_files_struct(struct files_struct *files)
> BUG();
> }
>
> +static struct file *
> +fget_from_files(struct files_struct *files, unsigned fd)
> +{
> + struct file *file;
> +
> + rcu_read_lock();
> + file = fcheck_files(files, fd);
> + if (file)
> + {
> + if (file->f_mode & FMODE_PATH
> + || !atomic_long_inc_not_zero(&file->f_count))
> + file = NULL;
> + }
> + rcu_read_unlock();
> +
> + return file;
> +}
>
> static long
> -eventfd_link_ioctl(struct file *f, unsigned int ioctl, unsigned long arg)
> +eventfd_link_ioctl_copy(unsigned long arg)
> {
> void __user *argp = (void __user *) arg;
> struct task_struct *task_target = NULL;
> @@ -75,91 +85,99 @@ eventfd_link_ioctl(struct file *f, unsigned int ioctl,
> unsigned long arg)
> struct files_struct *files;
> struct fdtable *fdt;
> struct eventfd_copy eventfd_copy;
> + long ret = -EFAULT;
>
> - switch (ioctl) {
> - case EVENTFD_COPY:
> - if (copy_from_user(&eventfd_copy, argp,
> - sizeof(struct eventfd_copy)))
> - return -EFAULT;
> -
> - /*
> - * Find the task struct for the target pid
> - */
> - task_target =
> - pid_task(find_vpid(eventfd_copy.target_pid),
> PIDTYPE_PID);
> - if (task_target == NULL) {
> - pr_debug("Failed to get mem ctx for target pid\n");
> - return -EFAULT;
> - }
> -
> - files = get_files_struct(current);
> - if (files == NULL) {
> - pr_debug("Failed to get files struct\n");
> - return -EFAULT;
> - }
> -
> - rcu_read_lock();
> - file = fcheck_files(files, eventfd_copy.source_fd);
> - if (file) {
> - if (file->f_mode & FMODE_PATH ||
> - !atomic_long_inc_not_zero(&file->f_count))
> - file = NULL;
> - }
> - rcu_read_unlock();
> - put_files_struct(files);
> + if (copy_from_user(&eventfd_copy, argp, sizeof(struct
> eventfd_copy)))
> + goto out;
> +
> + /*
> + * Find the task struct for the target pid
> + */
> + ret = -ESRCH;
> +
> + task_target =
> + get_pid_task(find_vpid(eventfd_copy.target_pid),
> PIDTYPE_PID);
> + if (task_target == NULL) {
> + pr_info("Unable to find pid %d\n",
> eventfd_copy.target_pid);
> + goto out;
> + }
> +
> + ret = -ESTALE;
> + files = get_files_struct(current);
> + if (files == NULL) {
> + pr_info("Failed to get current files struct\n");
> + goto out_task;
> + }
>
> - if (file == NULL) {
> - pr_debug("Failed to get file from source pid\n");
> - return 0;
> - }
> -
> - /*
> - * Release the existing eventfd in the source process
> - */
> - spin_lock(&files->file_lock);
> - fput(file);
> - filp_close(file, files);
> - fdt = files_fdtable(files);
> - fdt->fd[eventfd_copy.source_fd] = NULL;
> - spin_unlock(&files->file_lock);
> -
> - /*
> - * Find the file struct associated with the target fd.
> - */
> -
> - files = get_files_struct(task_target);
> - if (files == NULL) {
> - pr_debug("Failed to get files struct\n");
> - return -EFAULT;
> - }
> -
> - rcu_read_lock();
> - file = fcheck_files(files, eventfd_copy.target_fd);
> - if (file) {
> - if (file->f_mode & FMODE_PATH ||
> - !atomic_long_inc_not_zero(&file->f_count))
> - file = NULL;
> - }
> - rcu_read_unlock();
> + ret = -EBADF;
> + file = fget_from_files(files, eventfd_copy.source_fd);
> +
> + if (file == NULL) {
> + pr_info("Failed to get fd %d from source\n",
> + eventfd_copy.source_fd);
> put_files_struct(files);
> + goto out_task;
> + }
> +
> + /*
> + * Release the existing eventfd in the source process
> + */
> + spin_lock(&files->file_lock);
> + fput(file);
> + filp_close(file, files);
> + fdt = files_fdtable(files);
> + fdt->fd[eventfd_copy.source_fd] = NULL;
> + spin_unlock(&files->file_lock);
> +
> + put_files_struct(files);
> +
> + /*
> + * Find the file struct associated with the target fd.
> + */
> +
> + ret = -ESTALE;
> + files = get_files_struct(task_target);
> + if (files == NULL) {
> + pr_info("Failed to get target files struct\n");
> + goto out_task;
> + }
> +
> + ret = -EBADF;
> + file = fget_from_files(files, eventfd_copy.target_fd);
> + put_files_struct(files);
> +
> + if (file == NULL) {
> + pr_info("Failed to get fd %d from target\n",
> + eventfd_copy.target_fd);
> + goto out_task;
> + }
>
> - if (file == NULL) {
> - pr_debug("Failed to get file from target pid\n");
> - return 0;
> - }
> + /*
> + * Install the file struct from the target process into the
> + * file desciptor of the source process,
> + */
>
> - /*
> - * Install the file struct from the target process into the
> - * file desciptor of the source process,
> - */
> + fd_install(eventfd_copy.source_fd, file);
> + ret = 0;
>
> - fd_install(eventfd_copy.source_fd, file);
> +out_task:
> + put_task_struct(task_target);
> +out:
> + return ret;
> +}
>
> - return 0;
> +static long
> +eventfd_link_ioctl(struct file *f, unsigned int ioctl, unsigned long arg)
> +{
> + long ret = -ENOIOCTLCMD;
>
> - default:
> - return -ENOIOCTLCMD;
> + switch (ioctl) {
> + case EVENTFD_COPY:
> + ret = eventfd_link_ioctl_copy(arg);
> + break;
> }
> +
> + return ret;
> }
>
> static const struct file_operations eventfd_link_fops = {
> --
> 1.9.1
>
>
Hi Pavel,
2015-09-23 23:25, Pavel Boldin:
> Ping.
Are you requesting a review?
I think you should set Huawei Xie in the recipient list.
Other note: it is not easy to follow the evolution of your patches because
there is no cover letter and the numbering (v5) is not incremented.
These little details may make review happening ;)
Hi Thomas,
On Tue, Sep 29, 2015 at 10:42 PM, Thomas Monjalon <thomas.monjalon@6wind.com
> wrote:
> Hi Pavel,
>
> 2015-09-23 23:25, Pavel Boldin:
> > Ping.
>
> Are you requesting a review?
>
Yes.
> I think you should set Huawei Xie in the recipient list.
>
Huawei Xie CCed
>
> Other note: it is not easy to follow the evolution of your patches because
> there is no cover letter and the numbering (v5) is not incremented.
>
Should I reupload them then?
Pavel
On 8/29/2015 2:51 AM, Pavel Boldin wrote:
> * Move ioctl `EVENTFD_COPY' code to a separate function
> * Remove extra #includes
> * Introduce function fget_from_files
> * Fix ioctl return values
>
> Signed-off-by: Pavel Boldin <pboldin@mirantis.com>
Basically OK with this patch since we have reviewed before.
Could you split the patch, one change each patch? Thomas will require
you to do this too. :). I see you have also changed when to call
put_files_struct. It is better put it in a separate patch with the reason.
Another thing is code style. Run checkpatch.pl against your patch. There
are some issues.
The patchset contains an attempt at the refactoring the `eventfd_link`
kernel module that is used to steal an FD in DPDK.
The first patch refactors old EVENTFD_COPY handler fixing the codepath
and errors returned from the kernel space. This patch is retained
for the backward compatibility.
The next one introduces a new more clean implementation of the
EVENTFD_COPY2 ioctl that allocates a new fd for the `struct file'
being stolen.
The last patch uses this new mechanism in the DPDK userspace.
Pavel Boldin (3):
vhost: eventfd_link: refactoring EVENTFD_COPY handler
vhost: add EVENTFD_COPY2 ioctl
vhost: using EVENTFD_COPY2
lib/librte_vhost/eventfd_link/eventfd_link.c | 249 ++++++++++++++++++---------
lib/librte_vhost/eventfd_link/eventfd_link.h | 28 ++-
lib/librte_vhost/vhost_cuse/eventfd_copy.c | 54 ++++--
lib/librte_vhost/vhost_cuse/eventfd_copy.h | 6 +
lib/librte_vhost/vhost_cuse/vhost-net-cdev.c | 3 +
5 files changed, 231 insertions(+), 109 deletions(-)
On 10/29/2015 2:34 AM, Pavel Boldin wrote:
> The patchset contains an attempt at the refactoring the `eventfd_link`
> kernel module that is used to steal an FD in DPDK.
>
> The first patch refactors old EVENTFD_COPY handler fixing the codepath
> and errors returned from the kernel space. This patch is retained
> for the backward compatibility.
>
> The next one introduces a new more clean implementation of the
> EVENTFD_COPY2 ioctl that allocates a new fd for the `struct file'
> being stolen.
>
> The last patch uses this new mechanism in the DPDK userspace.
Pavel:
Don't forget signoff and version change message next time.
Or if you have time today, could you send a new version?
Acked-by: Huawei Xie <huawei.xie@intel.com>
> Pavel Boldin (3):
> vhost: eventfd_link: refactoring EVENTFD_COPY handler
> vhost: add EVENTFD_COPY2 ioctl
> vhost: using EVENTFD_COPY2
>
> lib/librte_vhost/eventfd_link/eventfd_link.c | 249 ++++++++++++++++++---------
> lib/librte_vhost/eventfd_link/eventfd_link.h | 28 ++-
> lib/librte_vhost/vhost_cuse/eventfd_copy.c | 54 ++++--
> lib/librte_vhost/vhost_cuse/eventfd_copy.h | 6 +
> lib/librte_vhost/vhost_cuse/vhost-net-cdev.c | 3 +
> 5 files changed, 231 insertions(+), 109 deletions(-)
>
2015-10-29 18:33, Xie, Huawei:
> On 10/29/2015 2:34 AM, Pavel Boldin wrote:
> > The patchset contains an attempt at the refactoring the `eventfd_link`
> > kernel module that is used to steal an FD in DPDK.
> >
> > The first patch refactors old EVENTFD_COPY handler fixing the codepath
> > and errors returned from the kernel space. This patch is retained
> > for the backward compatibility.
> >
> > The next one introduces a new more clean implementation of the
> > EVENTFD_COPY2 ioctl that allocates a new fd for the `struct file'
> > being stolen.
> >
> > The last patch uses this new mechanism in the DPDK userspace.
> Pavel:
> Don't forget signoff and version change message next time.
> Or if you have time today, could you send a new version?
>
> Acked-by: Huawei Xie <huawei.xie@intel.com>
Applied, thanks
@@ -22,18 +22,11 @@
* Intel Corporation
*/
-#include <linux/eventfd.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
-#include <linux/moduleparam.h>
-#include <linux/rcupdate.h>
#include <linux/file.h>
-#include <linux/slab.h>
-#include <linux/fs.h>
-#include <linux/mmu_context.h>
-#include <linux/sched.h>
-#include <asm/mmu_context.h>
#include <linux/fdtable.h>
+#include <linux/syscalls.h>
#include "eventfd_link.h"
@@ -65,9 +58,26 @@ put_files_struct(struct files_struct *files)
BUG();
}
+static struct file *
+fget_from_files(struct files_struct *files, unsigned fd)
+{
+ struct file *file;
+
+ rcu_read_lock();
+ file = fcheck_files(files, fd);
+ if (file)
+ {
+ if (file->f_mode & FMODE_PATH
+ || !atomic_long_inc_not_zero(&file->f_count))
+ file = NULL;
+ }
+ rcu_read_unlock();
+
+ return file;
+}
static long
-eventfd_link_ioctl(struct file *f, unsigned int ioctl, unsigned long arg)
+eventfd_link_ioctl_copy(unsigned long arg)
{
void __user *argp = (void __user *) arg;
struct task_struct *task_target = NULL;
@@ -75,91 +85,99 @@ eventfd_link_ioctl(struct file *f, unsigned int ioctl, unsigned long arg)
struct files_struct *files;
struct fdtable *fdt;
struct eventfd_copy eventfd_copy;
+ long ret = -EFAULT;
- switch (ioctl) {
- case EVENTFD_COPY:
- if (copy_from_user(&eventfd_copy, argp,
- sizeof(struct eventfd_copy)))
- return -EFAULT;
-
- /*
- * Find the task struct for the target pid
- */
- task_target =
- pid_task(find_vpid(eventfd_copy.target_pid), PIDTYPE_PID);
- if (task_target == NULL) {
- pr_debug("Failed to get mem ctx for target pid\n");
- return -EFAULT;
- }
-
- files = get_files_struct(current);
- if (files == NULL) {
- pr_debug("Failed to get files struct\n");
- return -EFAULT;
- }
-
- rcu_read_lock();
- file = fcheck_files(files, eventfd_copy.source_fd);
- if (file) {
- if (file->f_mode & FMODE_PATH ||
- !atomic_long_inc_not_zero(&file->f_count))
- file = NULL;
- }
- rcu_read_unlock();
- put_files_struct(files);
+ if (copy_from_user(&eventfd_copy, argp, sizeof(struct eventfd_copy)))
+ goto out;
+
+ /*
+ * Find the task struct for the target pid
+ */
+ ret = -ESRCH;
+
+ task_target =
+ get_pid_task(find_vpid(eventfd_copy.target_pid), PIDTYPE_PID);
+ if (task_target == NULL) {
+ pr_info("Unable to find pid %d\n", eventfd_copy.target_pid);
+ goto out;
+ }
+
+ ret = -ESTALE;
+ files = get_files_struct(current);
+ if (files == NULL) {
+ pr_info("Failed to get current files struct\n");
+ goto out_task;
+ }
- if (file == NULL) {
- pr_debug("Failed to get file from source pid\n");
- return 0;
- }
-
- /*
- * Release the existing eventfd in the source process
- */
- spin_lock(&files->file_lock);
- fput(file);
- filp_close(file, files);
- fdt = files_fdtable(files);
- fdt->fd[eventfd_copy.source_fd] = NULL;
- spin_unlock(&files->file_lock);
-
- /*
- * Find the file struct associated with the target fd.
- */
-
- files = get_files_struct(task_target);
- if (files == NULL) {
- pr_debug("Failed to get files struct\n");
- return -EFAULT;
- }
-
- rcu_read_lock();
- file = fcheck_files(files, eventfd_copy.target_fd);
- if (file) {
- if (file->f_mode & FMODE_PATH ||
- !atomic_long_inc_not_zero(&file->f_count))
- file = NULL;
- }
- rcu_read_unlock();
+ ret = -EBADF;
+ file = fget_from_files(files, eventfd_copy.source_fd);
+
+ if (file == NULL) {
+ pr_info("Failed to get fd %d from source\n",
+ eventfd_copy.source_fd);
put_files_struct(files);
+ goto out_task;
+ }
+
+ /*
+ * Release the existing eventfd in the source process
+ */
+ spin_lock(&files->file_lock);
+ fput(file);
+ filp_close(file, files);
+ fdt = files_fdtable(files);
+ fdt->fd[eventfd_copy.source_fd] = NULL;
+ spin_unlock(&files->file_lock);
+
+ put_files_struct(files);
+
+ /*
+ * Find the file struct associated with the target fd.
+ */
+
+ ret = -ESTALE;
+ files = get_files_struct(task_target);
+ if (files == NULL) {
+ pr_info("Failed to get target files struct\n");
+ goto out_task;
+ }
+
+ ret = -EBADF;
+ file = fget_from_files(files, eventfd_copy.target_fd);
+ put_files_struct(files);
+
+ if (file == NULL) {
+ pr_info("Failed to get fd %d from target\n",
+ eventfd_copy.target_fd);
+ goto out_task;
+ }
- if (file == NULL) {
- pr_debug("Failed to get file from target pid\n");
- return 0;
- }
+ /*
+ * Install the file struct from the target process into the
+ * file desciptor of the source process,
+ */
- /*
- * Install the file struct from the target process into the
- * file desciptor of the source process,
- */
+ fd_install(eventfd_copy.source_fd, file);
+ ret = 0;
- fd_install(eventfd_copy.source_fd, file);
+out_task:
+ put_task_struct(task_target);
+out:
+ return ret;
+}
- return 0;
+static long
+eventfd_link_ioctl(struct file *f, unsigned int ioctl, unsigned long arg)
+{
+ long ret = -ENOIOCTLCMD;
- default:
- return -ENOIOCTLCMD;
+ switch (ioctl) {
+ case EVENTFD_COPY:
+ ret = eventfd_link_ioctl_copy(arg);
+ break;
}
+
+ return ret;
}
static const struct file_operations eventfd_link_fops = {