X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Ffilemap_xip.c;h=8c199f537732088310c0e490cebe92c7414076bb;hb=242e54686257493f0b10ac557e730419d9af7d24;hp=7d63acd48817aed4446b161ad2a9e41d98f4b6b5;hpb=ceffc078528befc008c6f2c2c4decda79eabd534;p=linux-2.6

diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
index 7d63acd488..8c199f5377 100644
--- a/mm/filemap_xip.c
+++ b/mm/filemap_xip.c
@@ -68,13 +68,12 @@ do_xip_mapping_read(struct address_space *mapping,
 		if (unlikely(IS_ERR(page))) {
 			if (PTR_ERR(page) == -ENODATA) {
 				/* sparse */
-				page = virt_to_page(empty_zero_page);
+				page = ZERO_PAGE(0);
 			} else {
 				desc->error = PTR_ERR(page);
 				goto out;
 			}
-		} else
-			BUG_ON(!PageUptodate(page));
+		}
 
 		/* If users can be writing to this page using arbitrary
 		 * virtual addresses, take care about potential aliasing
@@ -84,8 +83,7 @@ do_xip_mapping_read(struct address_space *mapping,
 			flush_dcache_page(page);
 
 		/*
-		 * Ok, we have the page, and it's up-to-date, so
-		 * now we can copy it to user space...
+		 * Ok, we have the page, so now we can copy it to user space...
 		 *
 		 * The actor routine returns how many bytes were actually used..
 		 * NOTE! This may not be the same as how much of a user buffer
@@ -114,83 +112,28 @@ out:
 		file_accessed(filp);
 }
 
-/*
- * This is the "read()" routine for all filesystems
- * that uses the get_xip_page address space operation.
- */
-static ssize_t
-__xip_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
-		unsigned long nr_segs, loff_t *ppos)
-{
-	struct file *filp = iocb->ki_filp;
-	ssize_t retval;
-	unsigned long seg;
-	size_t count;
-
-	count = 0;
-	for (seg = 0; seg < nr_segs; seg++) {
-		const struct iovec *iv = &iov[seg];
-
-		/*
-		 * If any segment has a negative length, or the cumulative
-		 * length ever wraps negative then return -EINVAL.
-		 */
-		count += iv->iov_len;
-		if (unlikely((ssize_t)(count|iv->iov_len) < 0))
-			return -EINVAL;
-		if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len))
-			continue;
-		if (seg == 0)
-			return -EFAULT;
-		nr_segs = seg;
-		count -= iv->iov_len;	/* This segment is no good */
-		break;
-	}
-
-	retval = 0;
-	if (count) {
-		for (seg = 0; seg < nr_segs; seg++) {
-			read_descriptor_t desc;
-
-			desc.written = 0;
-			desc.arg.buf = iov[seg].iov_base;
-			desc.count = iov[seg].iov_len;
-			if (desc.count == 0)
-				continue;
-			desc.error = 0;
-			do_xip_mapping_read(filp->f_mapping, &filp->f_ra, filp,
-					    ppos, &desc, file_read_actor);
-			retval += desc.written;
-			if (!retval) {
-				retval = desc.error;
-				break;
-			}
-		}
-	}
-	return retval;
-}
-
 ssize_t
-xip_file_aio_read(struct kiocb *iocb, char __user *buf, size_t count,
-		  loff_t pos)
+xip_file_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
 {
-	struct iovec local_iov = { .iov_base = buf, .iov_len = count };
+	read_descriptor_t desc;
 
-	BUG_ON(iocb->ki_pos != pos);
-	return __xip_file_aio_read(iocb, &local_iov, 1, &iocb->ki_pos);
-}
-EXPORT_SYMBOL_GPL(xip_file_aio_read);
+	if (!access_ok(VERIFY_WRITE, buf, len))
+		return -EFAULT;
 
-ssize_t
-xip_file_readv(struct file *filp, const struct iovec *iov,
-	       unsigned long nr_segs, loff_t *ppos)
-{
-	struct kiocb kiocb;
+	desc.written = 0;
+	desc.arg.buf = buf;
+	desc.count = len;
+	desc.error = 0;
 
-	init_sync_kiocb(&kiocb, filp);
-	return __xip_file_aio_read(&kiocb, iov, nr_segs, ppos);
+	do_xip_mapping_read(filp->f_mapping, &filp->f_ra, filp,
+			    ppos, &desc, file_read_actor);
+
+	if (desc.written)
+		return desc.written;
+	else
+		return desc.error;
 }
-EXPORT_SYMBOL_GPL(xip_file_readv);
+EXPORT_SYMBOL_GPL(xip_file_read);
 
 ssize_t
 xip_file_sendfile(struct file *in_file, loff_t *ppos,
@@ -219,7 +162,7 @@ EXPORT_SYMBOL_GPL(xip_file_sendfile);
  * xip_write
  *
  * This function walks all vmas of the address_space and unmaps the
- * empty_zero_page when found at pgoff. Should it go in rmap.c?
+ * ZERO_PAGE when found at pgoff. Should it go in rmap.c?
  */
 static void
 __xip_unmap (struct address_space * mapping,
@@ -242,11 +185,11 @@ __xip_unmap (struct address_space * mapping,
 		 * We need the page_table_lock to protect us from page faults,
 		 * munmap, fork, etc...
 		 */
-		pte = page_check_address(virt_to_page(empty_zero_page), mm,
+		pte = page_check_address(ZERO_PAGE(address), mm,
 					 address);
 		if (!IS_ERR(pte)) {
 			/* Nuke the page table entry. */
-			flush_cache_page(vma, address, pte_pfn(pte));
+			flush_cache_page(vma, address, pte_pfn(*pte));
 			pteval = ptep_clear_flush(vma, address, pte);
 			BUG_ON(pte_dirty(pteval));
 			pte_unmap(pte);
@@ -285,7 +228,6 @@ xip_file_nopage(struct vm_area_struct * area,
 
 	page = mapping->a_ops->get_xip_page(mapping, pgoff*(PAGE_SIZE/512), 0);
 	if (!IS_ERR(page)) {
-		BUG_ON(!PageUptodate(page));
 		return page;
 	}
 	if (PTR_ERR(page) != -ENODATA)
@@ -300,12 +242,11 @@ xip_file_nopage(struct vm_area_struct * area,
 			pgoff*(PAGE_SIZE/512), 1);
 		if (IS_ERR(page))
 			return NULL;
-		BUG_ON(!PageUptodate(page));
 		/* unmap page at pgoff from all other vmas */
 		__xip_unmap(mapping, pgoff);
 	} else {
-		/* not shared and writable, use empty_zero_page */
-		page = virt_to_page(empty_zero_page);
+		/* not shared and writable, use ZERO_PAGE() */
+		page = ZERO_PAGE(address);
 	}
 
 	return page;
@@ -326,25 +267,19 @@ int xip_file_mmap(struct file * file, struct vm_area_struct * vma)
 EXPORT_SYMBOL_GPL(xip_file_mmap);
 
 static ssize_t
-do_xip_file_write(struct kiocb *iocb, const struct iovec *iov,
-		  unsigned long nr_segs, loff_t pos, loff_t *ppos,
-		  size_t count)
+__xip_file_write(struct file *filp, const char __user *buf,
+		  size_t count, loff_t pos, loff_t *ppos)
 {
-	struct file *file = iocb->ki_filp;
-	struct address_space * mapping = file->f_mapping;
+	struct address_space * mapping = filp->f_mapping;
 	struct address_space_operations *a_ops = mapping->a_ops;
 	struct inode 	*inode = mapping->host;
 	long		status = 0;
 	struct page	*page;
 	size_t		bytes;
-	const struct iovec *cur_iov = iov; /* current iovec */
-	size_t		iov_base = 0;	   /* offset in the current iovec */
-	char __user	*buf;
 	ssize_t		written = 0;
 
 	BUG_ON(!mapping->a_ops->get_xip_page);
 
-	buf = iov->iov_base;
 	do {
 		unsigned long index;
 		unsigned long offset;
@@ -365,15 +300,14 @@ do_xip_file_write(struct kiocb *iocb, const struct iovec *iov,
 		fault_in_pages_readable(buf, bytes);
 
 		page = a_ops->get_xip_page(mapping,
-						    index*(PAGE_SIZE/512), 0);
+					   index*(PAGE_SIZE/512), 0);
 		if (IS_ERR(page) && (PTR_ERR(page) == -ENODATA)) {
 			/* we allocate a new page unmap it */
 			page = a_ops->get_xip_page(mapping,
-				index*(PAGE_SIZE/512), 1);
+						   index*(PAGE_SIZE/512), 1);
 			if (!IS_ERR(page))
-			/* unmap page at pgoff from all other vmas */
-			__xip_unmap(mapping, index);
-
+				/* unmap page at pgoff from all other vmas */
+				__xip_unmap(mapping, index);
 		}
 
 		if (IS_ERR(page)) {
@@ -381,14 +315,7 @@ do_xip_file_write(struct kiocb *iocb, const struct iovec *iov,
 			break;
 		}
 
-		BUG_ON(!PageUptodate(page));
-
-		if (likely(nr_segs == 1))
-			copied = filemap_copy_from_user(page, offset,
-							buf, bytes);
-		else
-			copied = filemap_copy_from_user_iovec(page, offset,
-						cur_iov, iov_base, bytes);
+		copied = filemap_copy_from_user(page, offset, buf, bytes);
 		flush_dcache_page(page);
 		if (likely(copied > 0)) {
 			status = copied;
@@ -398,9 +325,6 @@ do_xip_file_write(struct kiocb *iocb, const struct iovec *iov,
 				count -= status;
 				pos += status;
 				buf += status;
-				if (unlikely(nr_segs > 1))
-					filemap_set_next_iovec(&cur_iov,
-							&iov_base, status);
 			}
 		}
 		if (unlikely(copied != bytes))
@@ -422,110 +346,52 @@ do_xip_file_write(struct kiocb *iocb, const struct iovec *iov,
 	return written ? written : status;
 }
 
-static ssize_t
-xip_file_aio_write_nolock(struct kiocb *iocb, const struct iovec *iov,
-				unsigned long nr_segs, loff_t *ppos)
+ssize_t
+xip_file_write(struct file *filp, const char __user *buf, size_t len,
+	       loff_t *ppos)
 {
-	struct file *file = iocb->ki_filp;
-	struct address_space * mapping = file->f_mapping;
-	size_t ocount;		/* original count */
-	size_t count;		/* after file limit checks */
-	struct inode 	*inode = mapping->host;
-	unsigned long	seg;
-	loff_t		pos;
-	ssize_t		written;
-	ssize_t		err;
+	struct address_space *mapping = filp->f_mapping;
+	struct inode *inode = mapping->host;
+	size_t count;
+	loff_t pos;
+	ssize_t ret;
 
-	ocount = 0;
-	for (seg = 0; seg < nr_segs; seg++) {
-		const struct iovec *iv = &iov[seg];
+	down(&inode->i_sem);
 
-		/*
-		 * If any segment has a negative length, or the cumulative
-		 * length ever wraps negative then return -EINVAL.
-		 */
-		ocount += iv->iov_len;
-		if (unlikely((ssize_t)(ocount|iv->iov_len) < 0))
-			return -EINVAL;
-		if (access_ok(VERIFY_READ, iv->iov_base, iv->iov_len))
-			continue;
-		if (seg == 0)
-			return -EFAULT;
-		nr_segs = seg;
-		ocount -= iv->iov_len;	/* This segment is no good */
-		break;
+	if (!access_ok(VERIFY_READ, buf, len)) {
+		ret=-EFAULT;
+		goto out_up;
 	}
 
-	count = ocount;
 	pos = *ppos;
+	count = len;
 
 	vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
 
-	written = 0;
-
-	err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
-	if (err)
-		goto out;
+	/* We can write back this queue in page reclaim */
+	current->backing_dev_info = mapping->backing_dev_info;
 
+	ret = generic_write_checks(filp, &pos, &count, S_ISBLK(inode->i_mode));
+	if (ret)
+		goto out_backing;
 	if (count == 0)
-		goto out;
+		goto out_backing;
 
-	err = remove_suid(file->f_dentry);
-	if (err)
-		goto out;
+	ret = remove_suid(filp->f_dentry);
+	if (ret)
+		goto out_backing;
 
 	inode_update_time(inode, 1);
 
-	/* use execute in place to copy directly to disk */
-	written = do_xip_file_write (iocb, iov,
-				  nr_segs, pos, ppos, count);
- out:
-	return written ? written : err;
-}
-
-static ssize_t
-__xip_file_write_nolock(struct file *file, const struct iovec *iov,
-			unsigned long nr_segs, loff_t *ppos)
-{
-	struct kiocb kiocb;
-
-	init_sync_kiocb(&kiocb, file);
-	return xip_file_aio_write_nolock(&kiocb, iov, nr_segs, ppos);
-}
-
-ssize_t
-xip_file_aio_write(struct kiocb *iocb, const char __user *buf,
-		       size_t count, loff_t pos)
-{
-	struct file *file = iocb->ki_filp;
-	struct address_space *mapping = file->f_mapping;
-	struct inode *inode = mapping->host;
-	ssize_t ret;
-	struct iovec local_iov = { .iov_base = (void __user *)buf,
-				   .iov_len = count };
+	ret = __xip_file_write (filp, buf, count, pos, ppos);
 
-	BUG_ON(iocb->ki_pos != pos);
-
-	down(&inode->i_sem);
-	ret = xip_file_aio_write_nolock(iocb, &local_iov, 1, &iocb->ki_pos);
-	up(&inode->i_sem);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(xip_file_aio_write);
-
-ssize_t xip_file_writev(struct file *file, const struct iovec *iov,
-			unsigned long nr_segs, loff_t *ppos)
-{
-	struct address_space *mapping = file->f_mapping;
-	struct inode *inode = mapping->host;
-	ssize_t ret;
-
-	down(&inode->i_sem);
-	ret = __xip_file_write_nolock(file, iov, nr_segs, ppos);
+ out_backing:
+	current->backing_dev_info = NULL;
+ out_up:
 	up(&inode->i_sem);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(xip_file_writev);
+EXPORT_SYMBOL_GPL(xip_file_write);
 
 /*
  * truncate a page used for execute in place
@@ -541,7 +407,6 @@ xip_truncate_page(struct address_space *mapping, loff_t from)
 	unsigned length;
 	struct page *page;
 	void *kaddr;
-	int err;
 
 	BUG_ON(!mapping->a_ops->get_xip_page);
 
@@ -556,26 +421,20 @@ xip_truncate_page(struct address_space *mapping, loff_t from)
 
 	page = mapping->a_ops->get_xip_page(mapping,
 					    index*(PAGE_SIZE/512), 0);
-	err = -ENOMEM;
 	if (!page)
-		goto out;
+		return -ENOMEM;
 	if (unlikely(IS_ERR(page))) {
-		if (PTR_ERR(page) == -ENODATA) {
+		if (PTR_ERR(page) == -ENODATA)
 			/* Hole? No need to truncate */
 			return 0;
-		} else {
-			err = PTR_ERR(page);
-			goto out;
-		}
-	} else
-		BUG_ON(!PageUptodate(page));
+		else
+			return PTR_ERR(page);
+	}
 	kaddr = kmap_atomic(page, KM_USER0);
 	memset(kaddr + offset, 0, length);
 	kunmap_atomic(kaddr, KM_USER0);
 
 	flush_dcache_page(page);
-	err = 0;
-out:
-	return err;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(xip_truncate_page);