Changes:
* Remove unnecessary #include's.
* Deindent by moving the code to an inline function.
* Fix return codes. Use appropriate return code for each fault cause.
* Remove copy-pasted `close_fd', call `sys_close' instead.
* Use `get_pid_task' to correctly reference the `task_target'.
Signed-off-by: Pavel Boldin <pboldin at mirantis.com>
---
Changes since last submission:
* Using `sys_close' to close fd.
* Removing unnecessary #include's.
lib/librte_vhost/eventfd_link/eventfd_link.c | 193 ++++++++++++++-------------
1 file changed, 98 insertions(+), 95 deletions(-)
diff --git a/lib/librte_vhost/eventfd_link/eventfd_link.c
b/lib/librte_vhost/eventfd_link/eventfd_link.c
index 7755dd6..d10e25f 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"
@@ -65,100 +58,110 @@ put_files_struct(struct files_struct *files)
BUG();
}
+static struct file *
+fget_from_files(struct files_struct *files, unsigned fd)
+{
+ struct file *file;
-static long
-eventfd_link_ioctl(struct file *f, unsigned int ioctl, unsigned long arg)
+ 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 inline long
+eventfd_link_ioctl_copy(unsigned long arg)
{
- void __user *argp = (void __user *) arg;
+ long ret = -EFAULT;
struct task_struct *task_target = NULL;
- struct file *file;
- struct files_struct *files;
- struct fdtable *fdt;
+ struct file *target_file = NULL;
+ struct files_struct *target_files = NULL;
struct eventfd_copy eventfd_copy;
+ struct pid *pid;
+
+ if (copy_from_user(&eventfd_copy, (void __user*)arg,
+ sizeof(struct eventfd_copy)))
+ goto out;
+
+ /*
+ * Find the task struct for the target pid
+ */
+ ret = -ESRCH;
+
+ pid = find_vpid(eventfd_copy.target_pid);
+ if (pid == NULL) {
+ pr_info("Unable to find pid %d\n", eventfd_copy.target_pid);
+ goto out;
+ }
+
+ task_target = get_pid_task(pid, PIDTYPE_PID);
+ if (task_target == NULL) {
+ pr_info("Failed to get task for pid %d\n",
+ eventfd_copy.target_pid);
+ goto out;
+ }
+
+ ret = sys_close(eventfd_copy.source_fd);
+ if (ret)
+ goto out_task;
+ ret = -ESTALE;
- switch (ioctl) {
+ /*
+ * Find the file struct associated with the target fd.
+ */
+
+ target_files = get_files_struct(task_target);
+ if (target_files == NULL) {
+ pr_info("Failed to get target files struct\n");
+ goto out_task;
+ }
+
+ ret = -EBADF;
+ target_file = fget_from_files(target_files, eventfd_copy.target_fd);
+
+ if (target_file == NULL) {
+ pr_info("Failed to get file from target pid\n");
+ goto out_target_files;
+ }
+
+
+ /*
+ * Install the file struct from the target process into the
+ * file desciptor of the source process,
+ */
+
+ fd_install(eventfd_copy.source_fd, target_file);
+
+ ret = 0;
+
+out_target_files:
+ put_files_struct(target_files);
+out_task:
+ put_task_struct(task_target);
+out:
+ return ret;
+}
+
+static long
+eventfd_link_ioctl(struct file *f, unsigned int ioctl, unsigned long arg)
+{
+ long ret = -ENOIOCTLCMD;
+
+ 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 (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);
- 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();
- put_files_struct(files);
-
- 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,
- */
-
- fd_install(eventfd_copy.source_fd, file);
-
- return 0;
-
- default:
- return -ENOIOCTLCMD;
+ ret = eventfd_link_ioctl_copy(arg);
+ break;
}
+
+ return ret;
}
static const struct file_operations eventfd_link_fops = {
--
1.9.1
