diff options
Diffstat (limited to 'linux-core/mmfs_drv.c')
| -rw-r--r-- | linux-core/mmfs_drv.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/linux-core/mmfs_drv.c b/linux-core/mmfs_drv.c index d973592d..88246297 100644 --- a/linux-core/mmfs_drv.c +++ b/linux-core/mmfs_drv.c @@ -32,6 +32,8 @@ #include <linux/fs.h> #include <linux/file.h> #include <linux/module.h> +#include <linux/mman.h> +#include <linux/pagemap.h> #include "mmfs.h" /** @file mmfs.c @@ -245,6 +247,45 @@ mmfs_pread_ioctl(struct inode *inode, struct file *filp, } /** + * Maps the contents of an object, returning the address it is mapped + * into. + * + * While the mapping holds a reference on the contents of the object, it doesn't + * imply a ref on the object itself. + */ +static int +mmfs_mmap_ioctl(struct inode *inode, struct file *filp, + unsigned int cmd, unsigned long arg) +{ + struct mmfs_file *mmfs_filp = filp->private_data; + struct mmfs_mmap_args args; + struct mmfs_object *obj; + loff_t offset; + + if (copy_from_user(&args, (void __user *)arg, sizeof(args))) + return -EFAULT; + + obj = mmfs_object_lookup(mmfs_filp, args.handle); + if (obj == NULL) + return -EINVAL; + + offset = args.offset; + + down_write(¤t->mm->mmap_sem); + args.addr = (void *)do_mmap(obj->filp, 0, args.size, + PROT_READ | PROT_WRITE, MAP_SHARED, + args.offset); + up_write(¤t->mm->mmap_sem); + + mmfs_object_unreference(obj); + + if (copy_to_user((void __user *)arg, &args, sizeof(args))) + return -EFAULT; + + return 0; +} + +/** * Writes data to the object referenced by handle. * * On error, the contents of the buffer that were to be modified are undefined. @@ -297,6 +338,8 @@ mmfs_ioctl(struct inode *inode, struct file *filp, return mmfs_pread_ioctl(inode, filp, cmd, arg); case MMFS_IOCTL_PWRITE: return mmfs_pwrite_ioctl(inode, filp, cmd, arg); + case MMFS_IOCTL_MMAP: + return mmfs_mmap_ioctl(inode, filp, cmd, arg); default: return -EINVAL; } |