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Commit ceffc078 authored by Carsten Otte's avatar Carsten Otte Committed by Linus Torvalds
Browse files

[PATCH] xip: fs/mm: execute in place 



- generic_file* file operations do no longer have a xip/non-xip split
- filemap_xip.c implements a new set of fops that require get_xip_page
  aop to work proper. all new fops are exported GPL-only (don't like to
  see whatever code use those except GPL modules)
- __xip_unmap now uses page_check_address, which is no longer static
  in rmap.c, and defined in linux/rmap.h
- mm/filemap.h is now much more clean, plainly having just Linus'
  inline funcs moved here from filemap.c
- fix includes in filemap_xip to make it build cleanly on i386

Signed-off-by: default avatarCarsten Otte <cotte@de.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 420edbcc

fs/open.c

+3 −1
Original line number Diff line number Diff line
@@ -808,7 +808,9 @@ struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags) 


	/* NB: we're sure to have correct a_ops only after f_op->open */

	if (f->f_flags & O_DIRECT) {

		if (!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO) {

		if (!f->f_mapping->a_ops ||

		    ((!f->f_mapping->a_ops->direct_IO) &&

		    (!f->f_mapping->a_ops->get_xip_page))) {

			fput(f);

			f = ERR_PTR(-EINVAL);

		}

include/linux/fs.h

+18 −0
Original line number Diff line number Diff line
@@ -330,6 +330,8 @@ struct address_space_operations { 
	int (*releasepage) (struct page *, int);

	ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,

			loff_t offset, unsigned long nr_segs);

	struct page* (*get_xip_page)(struct address_space *, sector_t,

			int);

};



struct backing_dev_info;
@@ -1497,6 +1499,22 @@ extern loff_t remote_llseek(struct file *file, loff_t offset, int origin); 
extern int generic_file_open(struct inode * inode, struct file * filp);

extern int nonseekable_open(struct inode * inode, struct file * filp);



#ifdef CONFIG_FS_XIP

extern ssize_t xip_file_aio_read(struct kiocb *iocb, char __user *buf,

				 size_t count, loff_t pos);

extern ssize_t xip_file_readv(struct file *filp, const struct iovec *iov,

			      unsigned long nr_segs, loff_t *ppos);

extern ssize_t xip_file_sendfile(struct file *in_file, loff_t *ppos,

				 size_t count, read_actor_t actor,

				 void *target);

extern int xip_file_mmap(struct file * file, struct vm_area_struct * vma);

extern ssize_t xip_file_aio_write(struct kiocb *iocb, const char __user *buf,

				  size_t count, loff_t pos);

extern ssize_t xip_file_writev(struct file *file, const struct iovec *iov,

			       unsigned long nr_segs, loff_t *ppos);

extern int xip_truncate_page(struct address_space *mapping, loff_t from);

#endif



static inline void do_generic_file_read(struct file * filp, loff_t *ppos,

					read_descriptor_t * desc,

					read_actor_t actor)

include/linux/rmap.h

+6 −0
Original line number Diff line number Diff line
@@ -92,6 +92,12 @@ static inline void page_dup_rmap(struct page *page) 
int page_referenced(struct page *, int is_locked, int ignore_token);

int try_to_unmap(struct page *);



/*

 * Called from mm/filemap_xip.c to unmap empty zero page

 */

pte_t *page_check_address(struct page *, struct mm_struct *, unsigned long);





/*

 * Used by swapoff to help locate where page is expected in vma.

 */

mm/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -19,3 +19,4 @@ obj-$(CONFIG_SPARSEMEM) += sparse.o 
obj-$(CONFIG_SHMEM) += shmem.o

obj-$(CONFIG_TINY_SHMEM) += tiny-shmem.o



obj-$(CONFIG_FS_XIP) += filemap_xip.o

mm/filemap.c

+2 −72
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <linux/blkdev.h>

#include <linux/security.h>

#include <linux/syscalls.h>

#include "filemap.h"

/*

 * FIXME: remove all knowledge of the buffer layer from the core VM

 */
@@ -1714,32 +1715,7 @@ int remove_suid(struct dentry *dentry) 
}

EXPORT_SYMBOL(remove_suid);



/*

 * Copy as much as we can into the page and return the number of bytes which

 * were sucessfully copied.  If a fault is encountered then clear the page

 * out to (offset+bytes) and return the number of bytes which were copied.

 */

static inline size_t

filemap_copy_from_user(struct page *page, unsigned long offset,

			const char __user *buf, unsigned bytes)

{

	char *kaddr;

	int left;



	kaddr = kmap_atomic(page, KM_USER0);

	left = __copy_from_user_inatomic(kaddr + offset, buf, bytes);

	kunmap_atomic(kaddr, KM_USER0);



	if (left != 0) {

		/* Do it the slow way */

		kaddr = kmap(page);

		left = __copy_from_user(kaddr + offset, buf, bytes);

		kunmap(page);

	}

	return bytes - left;

}



static size_t

size_t

__filemap_copy_from_user_iovec(char *vaddr, 

			const struct iovec *iov, size_t base, size_t bytes)

{
@@ -1766,52 +1742,6 @@ __filemap_copy_from_user_iovec(char *vaddr, 
	return copied - left;

}



/*

 * This has the same sideeffects and return value as filemap_copy_from_user().

 * The difference is that on a fault we need to memset the remainder of the

 * page (out to offset+bytes), to emulate filemap_copy_from_user()'s

 * single-segment behaviour.

 */

static inline size_t

filemap_copy_from_user_iovec(struct page *page, unsigned long offset,

			const struct iovec *iov, size_t base, size_t bytes)

{

	char *kaddr;

	size_t copied;



	kaddr = kmap_atomic(page, KM_USER0);

	copied = __filemap_copy_from_user_iovec(kaddr + offset, iov,

						base, bytes);

	kunmap_atomic(kaddr, KM_USER0);

	if (copied != bytes) {

		kaddr = kmap(page);

		copied = __filemap_copy_from_user_iovec(kaddr + offset, iov,

							base, bytes);

		kunmap(page);

	}

	return copied;

}



static inline void

filemap_set_next_iovec(const struct iovec **iovp, size_t *basep, size_t bytes)

{

	const struct iovec *iov = *iovp;

	size_t base = *basep;



	while (bytes) {

		int copy = min(bytes, iov->iov_len - base);



		bytes -= copy;

		base += copy;

		if (iov->iov_len == base) {

			iov++;

			base = 0;

		}

	}

	*iovp = iov;

	*basep = base;

}



/*

 * Performs necessary checks before doing a write

 *