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#include <linux/fcntl.h>
#include <linux/fs.h>
#include <linux/anon_inodes.h>
#include <linux/fsnotify_backend.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include "fanotify.h"
static int fanotify_release(struct inode *ignored, struct file *file)
{
struct fsnotify_group *group = file->private_data;
pr_debug("%s: file=%p group=%p\n", __func__, file, group);
/* matches the fanotify_init->fsnotify_alloc_group */
fsnotify_put_group(group);
return 0;
}
static const struct file_operations fanotify_fops = {
.poll = NULL,
.read = NULL,
.fasync = NULL,
.release = fanotify_release,
.unlocked_ioctl = NULL,
.compat_ioctl = NULL,
};
/* fanotify syscalls */
SYSCALL_DEFINE3(fanotify_init, unsigned int, flags, unsigned int, event_f_flags,
unsigned int, priority)
{
struct fsnotify_group *group;
int f_flags, fd;
pr_debug("%s: flags=%d event_f_flags=%d priority=%d\n",
__func__, flags, event_f_flags, priority);
if (event_f_flags)
return -EINVAL;
if (priority)
return -EINVAL;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (flags & ~FAN_ALL_INIT_FLAGS)
return -EINVAL;
f_flags = (O_RDONLY | FMODE_NONOTIFY);
if (flags & FAN_CLOEXEC)
f_flags |= O_CLOEXEC;
if (flags & FAN_NONBLOCK)
f_flags |= O_NONBLOCK;
/* fsnotify_alloc_group takes a ref. Dropped in fanotify_release */
group = fsnotify_alloc_group(&fanotify_fsnotify_ops);
if (IS_ERR(group))
return PTR_ERR(group);
fd = anon_inode_getfd("[fanotify]", &fanotify_fops, group, f_flags);
if (fd < 0)
goto out_put_group;
return fd;
out_put_group:
fsnotify_put_group(group);
return fd;
}
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