From e658d997498502e95aa4e5dd8970c3d7a1614873 Mon Sep 17 00:00:00 2001 From: Pavel Boldin Date: Wed, 28 Oct 2015 20:33:47 +0200 Subject: [PATCH] vhost: refactor eventfd copy handler * 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 Acked-by: Huawei Xie --- lib/librte_vhost/eventfd_link/eventfd_link.c | 181 ++++++++++--------- 1 file changed, 100 insertions(+), 81 deletions(-) diff --git a/lib/librte_vhost/eventfd_link/eventfd_link.c b/lib/librte_vhost/eventfd_link/eventfd_link.c index 62c45c8da0..7cbebd47fc 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 #include #include -#include -#include #include -#include -#include -#include -#include -#include #include +#include #include "eventfd_link.h" @@ -65,9 +58,27 @@ 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 +86,99 @@ 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; - } + if (copy_from_user(&eventfd_copy, argp, sizeof(struct eventfd_copy))) + goto out; - files = get_files_struct(current); - if (files == NULL) { - pr_debug("Failed to get files struct\n"); - return -EFAULT; - } + /* + * Find the task struct for the target pid + */ + ret = -ESRCH; - 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); + 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; + } - if (file == NULL) { - pr_debug("Failed to get file from source pid\n"); - return 0; - } + ret = -ESTALE; + files = get_files_struct(current); + if (files == NULL) { + pr_info("Failed to get current files struct\n"); + 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); - - /* - * 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; - } + ret = -EBADF; + file = fget_from_files(files, eventfd_copy.source_fd); - 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(); + if (file == NULL) { + pr_info("Failed to get fd %d from source\n", + eventfd_copy.source_fd); put_files_struct(files); + goto out_task; + } - if (file == NULL) { - pr_debug("Failed to get file from target 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); + + 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); - /* - * Install the file struct from the target process into the - * file desciptor of the source process, - */ + if (file == NULL) { + pr_info("Failed to get fd %d from target\n", + eventfd_copy.target_fd); + goto out_task; + } - fd_install(eventfd_copy.source_fd, file); + /* + * Install the file struct from the target process into the + * file desciptor of the source process, + */ - return 0; + fd_install(eventfd_copy.source_fd, file); + ret = 0; - default: - return -ENOIOCTLCMD; +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: + ret = eventfd_link_ioctl_copy(arg); + break; } + + return ret; } static const struct file_operations eventfd_link_fops = { -- 2.20.1