Hi John! On Thu, Jun 4, 2015 at 9:41 PM, John Baldwin <[email protected]> wrote: > Author: jhb > Date: Thu Jun 4 19:41:15 2015 > New Revision: 283998 > URL: https://svnweb.freebsd.org/changeset/base/283998 > > Log: > Add a new file operations hook for mmap operations. File type-specific > logic is now placed in the mmap hook implementation rather than requiring > it to be placed in sys/vm/vm_mmap.c. This hook allows new file types to > support mmap() as well as potentially allowing mmap() for existing file > types that do not currently support any mapping. > > The vm_mmap() function is now split up into two functions. A new > vm_mmap_object() function handles the "back half" of vm_mmap() and accepts > a referenced VM object to map rather than a (handle, handle_type) tuple. > vm_mmap() is now reduced to converting a (handle, handle_type) tuple to a > a VM object and then calling vm_mmap_object() to handle the actual mapping. > The vm_mmap() function remains for use by other parts of the kernel > (e.g. device drivers and exec) but now only supports mapping vnodes, > character devices, and anonymous memory. > > The mmap() system call invokes vm_mmap_object() directly with a NULL object > for anonymous mappings. For mappings using a file descriptor, the > descriptors fo_mmap() hook is invoked instead. The fo_mmap() hook is > responsible for performing type-specific checks and adjustments to > arguments as well as possibly modifying mapping parameters such as flags > or the object offset. The fo_mmap() hook routines then call > vm_mmap_object() to handle the actual mapping. > > The fo_mmap() hook is optional. If it is not set, then fo_mmap() will > fail with ENODEV. A fo_mmap() hook is implemented for regular files, > character devices, and shared memory objects (created via shm_open()). > > While here, consistently use the VM_PROT_* constants for the vm_prot_t > type for the 'prot' variable passed to vm_mmap() and vm_mmap_object() > as well as the vm_mmap_vnode() and vm_mmap_cdev() helper routines. > Previously some places were using the mmap()-specific PROT_* constants > instead. While this happens to work because PROT_xx == VM_PROT_xx, > using VM_PROT_* is more correct. > > Differential Revision: https://reviews.freebsd.org/D2658 > Reviewed by: alc (glanced over), kib > MFC after: 1 month > Sponsored by: Chelsio > > Modified: > head/sys/dev/drm/drm_bufs.c > head/sys/dev/drm2/drm_bufs.c > head/sys/fs/devfs/devfs_vnops.c > head/sys/kern/subr_uio.c > head/sys/kern/uipc_shm.c > head/sys/kern/vfs_vnops.c > head/sys/sys/file.h > head/sys/sys/mman.h > head/sys/vm/vm_extern.h > head/sys/vm/vm_mmap.c >
> ... patch trimmed... When plan you to MFC this change to 10-STABLE? Thank, Oliver > _______________________________________________ > [email protected] mailing list > http://lists.freebsd.org/mailman/listinfo/svn-src-head > To unsubscribe, send any mail to "[email protected]" _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "[email protected]"
