Exemplo n.º 1
0
struct dentry *f2fs_get_parent(struct dentry *child)
{
	struct qstr dotdot = {.name = "..", .len = 2};
	unsigned long ino = f2fs_inode_by_name(child->d_inode, &dotdot);
	if (!ino)
		return ERR_PTR(-ENOENT);
	return d_obtain_alias(f2fs_iget(child->d_inode->i_sb, ino));
}

static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
		struct nameidata *nd)
{
	struct inode *inode = NULL;
	struct f2fs_dir_entry *de;
	struct page *page;

	if (dentry->d_name.len > F2FS_NAME_LEN)
		return ERR_PTR(-ENAMETOOLONG);

	de = f2fs_find_entry(dir, &dentry->d_name, &page);
	if (de) {
		nid_t ino = le32_to_cpu(de->ino);
		kunmap(page);
		f2fs_put_page(page, 0);

		inode = f2fs_iget(dir->i_sb, ino);
		if (IS_ERR(inode))
			return ERR_CAST(inode);
	}

	return d_splice_alias(inode, dentry);
}

static int f2fs_unlink(struct inode *dir, struct dentry *dentry)
{
	struct super_block *sb = dir->i_sb;
	struct f2fs_sb_info *sbi = F2FS_SB(sb);
	struct inode *inode = dentry->d_inode;
	struct f2fs_dir_entry *de;
	struct page *page;
	int err = -ENOENT;

	trace_f2fs_unlink_enter(dir, dentry);
	f2fs_balance_fs(sbi);

	de = f2fs_find_entry(dir, &dentry->d_name, &page);
	if (!de)
		goto fail;

	f2fs_lock_op(sbi);
	err = acquire_orphan_inode(sbi);
	if (err) {
		f2fs_unlock_op(sbi);
		kunmap(page);
		f2fs_put_page(page, 0);
		goto fail;
	}
	f2fs_delete_entry(de, page, inode);
	f2fs_unlock_op(sbi);

	/* In order to evict this inode,  we set it dirty */
	mark_inode_dirty(inode);
fail:
	trace_f2fs_unlink_exit(inode, err);
	return err;
}

static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
					const char *symname)
{
	struct super_block *sb = dir->i_sb;
	struct f2fs_sb_info *sbi = F2FS_SB(sb);
	struct inode *inode;
	size_t symlen = strlen(symname) + 1;
	int err;

	f2fs_balance_fs(sbi);

	inode = f2fs_new_inode(dir, S_IFLNK | S_IRWXUGO);
	if (IS_ERR(inode))
		return PTR_ERR(inode);

	inode->i_op = &f2fs_symlink_inode_operations;
	inode->i_mapping->a_ops = &f2fs_dblock_aops;

	f2fs_lock_op(sbi);
	err = f2fs_add_link(dentry, inode);
	f2fs_unlock_op(sbi);
	if (err)
		goto out;

	err = page_symlink(inode, symname, symlen);
	alloc_nid_done(sbi, inode->i_ino);

	d_instantiate(dentry, inode);
	unlock_new_inode(inode);
	return err;
out:
	clear_nlink(inode);
	unlock_new_inode(inode);
	make_bad_inode(inode);
	iput(inode);
	alloc_nid_failed(sbi, inode->i_ino);
	return err;
}

static int f2fs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
	struct inode *inode;
	int err;

	f2fs_balance_fs(sbi);

	inode = f2fs_new_inode(dir, S_IFDIR | mode);
	if (IS_ERR(inode))
		return PTR_ERR(inode);

	inode->i_op = &f2fs_dir_inode_operations;
	inode->i_fop = &f2fs_dir_operations;
	inode->i_mapping->a_ops = &f2fs_dblock_aops;
	mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_ZERO);

	set_inode_flag(F2FS_I(inode), FI_INC_LINK);
	f2fs_lock_op(sbi);
	err = f2fs_add_link(dentry, inode);
	f2fs_unlock_op(sbi);
	if (err)
		goto out_fail;

	alloc_nid_done(sbi, inode->i_ino);

	d_instantiate(dentry, inode);
	unlock_new_inode(inode);

	return 0;

out_fail:
	clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
	clear_nlink(inode);
	unlock_new_inode(inode);
	make_bad_inode(inode);
	iput(inode);
	alloc_nid_failed(sbi, inode->i_ino);
	return err;
}

static int f2fs_rmdir(struct inode *dir, struct dentry *dentry)
{
	struct inode *inode = dentry->d_inode;
	if (f2fs_empty_dir(inode))
		return f2fs_unlink(dir, dentry);
	return -ENOTEMPTY;
}

static int f2fs_mknod(struct inode *dir, struct dentry *dentry,
				umode_t mode, dev_t rdev)
{
	struct super_block *sb = dir->i_sb;
	struct f2fs_sb_info *sbi = F2FS_SB(sb);
	struct inode *inode;
	int err = 0;

	if (!new_valid_dev(rdev))
		return -EINVAL;

	f2fs_balance_fs(sbi);

	inode = f2fs_new_inode(dir, mode);
	if (IS_ERR(inode))
		return PTR_ERR(inode);

	init_special_inode(inode, inode->i_mode, rdev);
	inode->i_op = &f2fs_special_inode_operations;

	f2fs_lock_op(sbi);
	err = f2fs_add_link(dentry, inode);
	f2fs_unlock_op(sbi);
	if (err)
		goto out;

	alloc_nid_done(sbi, inode->i_ino);
	d_instantiate(dentry, inode);
	unlock_new_inode(inode);
	return 0;
out:
	clear_nlink(inode);
	unlock_new_inode(inode);
	make_bad_inode(inode);
	iput(inode);
	alloc_nid_failed(sbi, inode->i_ino);
	return err;
}

static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
			struct inode *new_dir, struct dentry *new_dentry)
{
	struct super_block *sb = old_dir->i_sb;
	struct f2fs_sb_info *sbi = F2FS_SB(sb);
	struct inode *old_inode = old_dentry->d_inode;
	struct inode *new_inode = new_dentry->d_inode;
	struct page *old_dir_page;
	struct page *old_page, *new_page;
	struct f2fs_dir_entry *old_dir_entry = NULL;
	struct f2fs_dir_entry *old_entry;
	struct f2fs_dir_entry *new_entry;
	int err = -ENOENT;

	f2fs_balance_fs(sbi);

	old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
	if (!old_entry)
		goto out;

	if (S_ISDIR(old_inode->i_mode)) {
		err = -EIO;
		old_dir_entry = f2fs_parent_dir(old_inode, &old_dir_page);
		if (!old_dir_entry)
			goto out_old;
	}

	f2fs_lock_op(sbi);

	if (new_inode) {

		err = -ENOTEMPTY;
		if (old_dir_entry && !f2fs_empty_dir(new_inode))
			goto out_dir;

		err = -ENOENT;
		new_entry = f2fs_find_entry(new_dir, &new_dentry->d_name,
						&new_page);
		if (!new_entry)
			goto out_dir;

		err = acquire_orphan_inode(sbi);
		if (err)
			goto put_out_dir;

		if (update_dent_inode(old_inode, &new_dentry->d_name)) {
			release_orphan_inode(sbi);
			goto put_out_dir;
		}

		f2fs_set_link(new_dir, new_entry, new_page, old_inode);
		F2FS_I(old_inode)->i_pino = new_dir->i_ino;

		new_inode->i_ctime = CURRENT_TIME;
		if (old_dir_entry)
			drop_nlink(new_inode);
		drop_nlink(new_inode);
		mark_inode_dirty(new_inode);

		if (!new_inode->i_nlink)
			add_orphan_inode(sbi, new_inode->i_ino);
		else
			release_orphan_inode(sbi);

		update_inode_page(old_inode);
		update_inode_page(new_inode);
	} else {
		err = f2fs_add_link(new_dentry, old_inode);
		if (err)
			goto out_dir;

		if (old_dir_entry) {
			inc_nlink(new_dir);
			update_inode_page(new_dir);
		}
	}

	old_inode->i_ctime = CURRENT_TIME;
	mark_inode_dirty(old_inode);

	f2fs_delete_entry(old_entry, old_page, NULL);

	if (old_dir_entry) {
		if (old_dir != new_dir) {
			f2fs_set_link(old_inode, old_dir_entry,
						old_dir_page, new_dir);
			F2FS_I(old_inode)->i_pino = new_dir->i_ino;
			update_inode_page(old_inode);
		} else {
			kunmap(old_dir_page);
			f2fs_put_page(old_dir_page, 0);
		}
		drop_nlink(old_dir);
		mark_inode_dirty(old_dir);
		update_inode_page(old_dir);
	}

	f2fs_unlock_op(sbi);
	return 0;

put_out_dir:
	if (PageLocked(new_page))
		f2fs_put_page(new_page, 1);
	else
		f2fs_put_page(new_page, 0);
out_dir:
	if (old_dir_entry) {
		kunmap(old_dir_page);
		f2fs_put_page(old_dir_page, 0);
	}
	f2fs_unlock_op(sbi);
out_old:
	kunmap(old_page);
	f2fs_put_page(old_page, 0);
out:
	return err;
}

const struct inode_operations f2fs_dir_inode_operations = {
	.create		= f2fs_create,
	.lookup		= f2fs_lookup,
	.link		= f2fs_link,
	.unlink		= f2fs_unlink,
	.symlink	= f2fs_symlink,
	.mkdir		= f2fs_mkdir,
	.rmdir		= f2fs_rmdir,
	.mknod		= f2fs_mknod,
	.rename		= f2fs_rename,
	.getattr	= f2fs_getattr,
	.setattr	= f2fs_setattr,
	.get_acl	= f2fs_get_acl,
#ifdef CONFIG_F2FS_FS_XATTR
	.setxattr	= generic_setxattr,
	.getxattr	= generic_getxattr,
	.listxattr	= f2fs_listxattr,
	.removexattr	= generic_removexattr,
#endif
};

const struct inode_operations f2fs_symlink_inode_operations = {
	.readlink       = generic_readlink,
	.follow_link    = page_follow_link_light,
	.put_link       = page_put_link,
	.getattr	= f2fs_getattr,
	.setattr	= f2fs_setattr,
#ifdef CONFIG_F2FS_FS_XATTR
	.setxattr	= generic_setxattr,
	.getxattr	= generic_getxattr,
	.listxattr	= f2fs_listxattr,
	.removexattr	= generic_removexattr,
#endif
};

const struct inode_operations f2fs_special_inode_operations = {
	.getattr	= f2fs_getattr,
	.setattr        = f2fs_setattr,
	.get_acl	= f2fs_get_acl,
#ifdef CONFIG_F2FS_FS_XATTR
	.setxattr       = generic_setxattr,
	.getxattr       = generic_getxattr,
	.listxattr	= f2fs_listxattr,
	.removexattr    = generic_removexattr,
#endif
};
Exemplo n.º 2
0
static void __free_pages_ok (struct page *page, unsigned int order)
{
	unsigned long index, page_idx, mask, flags;
	free_area_t *area;
	struct page *base;
	zone_t *zone;

	/*
	 * Yes, think what happens when other parts of the kernel take 
	 * a reference to a page in order to pin it for io. -ben
	 */
	if (PageLRU(page)) {
		if (unlikely(in_interrupt()))
			BUG();
		lru_cache_del(page);
	}

	if (page->buffers)
		BUG();
	if (page->mapping)
		BUG();
	if (!VALID_PAGE(page))
		BUG();
	if (PageLocked(page))
		BUG();
	if (PageActive(page))
		BUG();
	page->flags &= ~((1<<PG_referenced) | (1<<PG_dirty));

	if (current->flags & PF_FREE_PAGES)
		goto local_freelist;
 back_local_freelist:

	zone = page_zone(page);

	mask = (~0UL) << order;
	base = zone->zone_mem_map;
	page_idx = page - base;
	if (page_idx & ~mask)
		BUG();
	index = page_idx >> (1 + order);

	area = zone->free_area + order;

	spin_lock_irqsave(&zone->lock, flags);

	zone->free_pages -= mask;

	while (mask + (1 << (MAX_ORDER-1))) {
		struct page *buddy1, *buddy2;

		if (area >= zone->free_area + MAX_ORDER)
			BUG();
		if (!__test_and_change_bit(index, area->map))
			/*
			 * the buddy page is still allocated.
			 */
			break;
		/*
		 * Move the buddy up one level.
		 * This code is taking advantage of the identity:
		 * 	-mask = 1+~mask
		 */
		buddy1 = base + (page_idx ^ -mask);
		buddy2 = base + page_idx;
		if (BAD_RANGE(zone,buddy1))
			BUG();
		if (BAD_RANGE(zone,buddy2))
			BUG();

		list_del(&buddy1->list);
		mask <<= 1;
		area++;
		index >>= 1;
		page_idx &= mask;
	}
	list_add(&(base + page_idx)->list, &area->free_list);

	spin_unlock_irqrestore(&zone->lock, flags);
	return;

 local_freelist:
	if (current->nr_local_pages)
		goto back_local_freelist;
	if (in_interrupt())
		goto back_local_freelist;		

	list_add(&page->list, &current->local_pages);
	page->index = order;
	current->nr_local_pages++;
}
Exemplo n.º 3
0
/*
 * AFS read page from file, directory or symlink
 */
static int afs_readpage(struct file *file, struct page *page)
{
	struct afs_vnode *vnode;
	struct inode *inode;
	struct key *key;
	size_t len;
	off_t offset;
	int ret;

	inode = page->mapping->host;

	if (file) {
		key = file->private_data;
		ASSERT(key != NULL);
	} else {
		key = afs_request_key(AFS_FS_S(inode->i_sb)->volume->cell);
		if (IS_ERR(key)) {
			ret = PTR_ERR(key);
			goto error_nokey;
		}
	}

	_enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index);

	vnode = AFS_FS_I(inode);

	BUG_ON(!PageLocked(page));

	ret = -ESTALE;
	if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
		goto error;

	/* is it cached? */
#ifdef CONFIG_AFS_FSCACHE
	ret = fscache_read_or_alloc_page(vnode->cache,
					 page,
					 afs_file_readpage_read_complete,
					 NULL,
					 GFP_KERNEL);
#else
	ret = -ENOBUFS;
#endif
	switch (ret) {
		/* read BIO submitted (page in cache) */
	case 0:
		break;

		/* page not yet cached */
	case -ENODATA:
		_debug("cache said ENODATA");
		goto go_on;

		/* page will not be cached */
	case -ENOBUFS:
		_debug("cache said ENOBUFS");
	default:
	go_on:
		offset = page->index << PAGE_CACHE_SHIFT;
		len = min_t(size_t, i_size_read(inode) - offset, PAGE_SIZE);

		/* read the contents of the file from the server into the
		 * page */
		ret = afs_vnode_fetch_data(vnode, key, offset, len, page);
		if (ret < 0) {
			if (ret == -ENOENT) {
				_debug("got NOENT from server"
				       " - marking file deleted and stale");
				set_bit(AFS_VNODE_DELETED, &vnode->flags);
				ret = -ESTALE;
			}

#ifdef CONFIG_AFS_FSCACHE
			fscache_uncache_page(vnode->cache, page);
#endif
			BUG_ON(PageFsCache(page));
			goto error;
		}

		SetPageUptodate(page);

		/* send the page to the cache */
#ifdef CONFIG_AFS_FSCACHE
		if (PageFsCache(page) &&
		    fscache_write_page(vnode->cache, page, GFP_KERNEL) != 0) {
			fscache_uncache_page(vnode->cache, page);
			BUG_ON(PageFsCache(page));
		}
#endif
		unlock_page(page);
	}

	if (!file)
		key_put(key);
	_leave(" = 0");
	return 0;

error:
	SetPageError(page);
	unlock_page(page);
	if (!file)
		key_put(key);
error_nokey:
	_leave(" = %d", ret);
	return ret;
}
Exemplo n.º 4
0
Arquivo: file.c Projeto: cilynx/dd-wrt
int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg)
{
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	struct jffs2_node_frag *frag = f->fraglist;
	__u32 offset = pg->index << PAGE_CACHE_SHIFT;
	__u32 end = offset + PAGE_CACHE_SIZE;
	unsigned char *pg_buf;
	int ret;

	D1(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%x\n", inode->i_ino, offset));

	if (!PageLocked(pg))
                PAGE_BUG(pg);

	while(frag && frag->ofs + frag->size  <= offset) {
		//		D1(printk(KERN_DEBUG "skipping frag %d-%d; before the region we care about\n", frag->ofs, frag->ofs + frag->size));
		frag = frag->next;
	}

	pg_buf = kmap(pg);

	/* XXX FIXME: Where a single physical node actually shows up in two
	   frags, we read it twice. Don't do that. */
	/* Now we're pointing at the first frag which overlaps our page */
	while(offset < end) {
		D2(printk(KERN_DEBUG "jffs2_readpage: offset %d, end %d\n", offset, end));
		if (!frag || frag->ofs > offset) {
			__u32 holesize = end - offset;
			if (frag) {
				D1(printk(KERN_NOTICE "Eep. Hole in ino %ld fraglist. frag->ofs = 0x%08x, offset = 0x%08x\n", inode->i_ino, frag->ofs, offset));
				holesize = min(holesize, frag->ofs - offset);
				D1(jffs2_print_frag_list(f));
			}
			D1(printk(KERN_DEBUG "Filling non-frag hole from %d-%d\n", offset, offset+holesize));
			memset(pg_buf, 0, holesize);
			pg_buf += holesize;
			offset += holesize;
			continue;
		} else if (frag->ofs < offset && (offset & (PAGE_CACHE_SIZE-1)) != 0) {
			D1(printk(KERN_NOTICE "Eep. Overlap in ino #%ld fraglist. frag->ofs = 0x%08x, offset = 0x%08x\n",
				  inode->i_ino, frag->ofs, offset));
			D1(jffs2_print_frag_list(f));
			memset(pg_buf, 0, end - offset);
			ClearPageUptodate(pg);
			SetPageError(pg);
			kunmap(pg);
			return -EIO;
		} else if (!frag->node) {
			__u32 holeend = min(end, frag->ofs + frag->size);
			D1(printk(KERN_DEBUG "Filling frag hole from %d-%d (frag 0x%x 0x%x)\n", offset, holeend, frag->ofs, frag->ofs + frag->size));
			memset(pg_buf, 0, holeend - offset);
			pg_buf += holeend - offset;
			offset = holeend;
			frag = frag->next;
			continue;
		} else {
			__u32 readlen;
			__u32 fragofs; /* offset within the frag to start reading */

			fragofs = offset - frag->ofs;
			readlen = min(frag->size - fragofs, end - offset);
			D1(printk(KERN_DEBUG "Reading %d-%d from node at 0x%x\n", frag->ofs+fragofs, 
				  fragofs+frag->ofs+readlen, frag->node->raw->flash_offset & ~3));
			ret = jffs2_read_dnode(c, frag->node, pg_buf, fragofs + frag->ofs - frag->node->ofs, readlen);
			D2(printk(KERN_DEBUG "node read done\n"));
			if (ret) {
				D1(printk(KERN_DEBUG"jffs2_readpage error %d\n",ret));
				memset(pg_buf, 0, readlen);
				ClearPageUptodate(pg);
				SetPageError(pg);
				kunmap(pg);
				return ret;
			}
		
			pg_buf += readlen;
			offset += readlen;
			frag = frag->next;
			D2(printk(KERN_DEBUG "node read was OK. Looping\n"));
		}
	}
	D2(printk(KERN_DEBUG "readpage finishing\n"));
	SetPageUptodate(pg);
	ClearPageError(pg);

	flush_dcache_page(pg);

	kunmap(pg);
	D1(printk(KERN_DEBUG "readpage finished\n"));
	return 0;
}
Exemplo n.º 5
0
int lock_kiovec(int nr, struct kiobuf *iovec[], int wait)
{
	struct kiobuf *iobuf;
	int i, j;
	struct page *page, **ppage;
	int doublepage = 0;
	int repeat = 0;
	
 repeat:
	
	for (i = 0; i < nr; i++) {
		iobuf = iovec[i];

		if (iobuf->locked)
			continue;
		iobuf->locked = 1;

		ppage = iobuf->maplist;
		for (j = 0; j < iobuf->nr_pages; ppage++, j++) {
			page = *ppage;
			if (!page)
				continue;
			
			if (TryLockPage(page))
				goto retry;
		}
	}

	return 0;
	
 retry:
	
	/* 
	 * We couldn't lock one of the pages.  Undo the locking so far,
	 * wait on the page we got to, and try again.  
	 */
	
	unlock_kiovec(nr, iovec);
	if (!wait)
		return -EAGAIN;
	
	/* 
	 * Did the release also unlock the page we got stuck on?
	 */
	if (!PageLocked(page)) {
		/* 
		 * If so, we may well have the page mapped twice
		 * in the IO address range.  Bad news.  Of
		 * course, it _might_ just be a coincidence,
		 * but if it happens more than once, chances
		 * are we have a double-mapped page. 
		 */
		if (++doublepage >= 3) 
			return -EINVAL;
		
		/* Try again...  */
		wait_on_page(page);
	}
	
	if (++repeat < 16)
		goto repeat;
	return -EAGAIN;
}
Exemplo n.º 6
0
/*
 * AFS read page from file, directory or symlink
 */
static int afs_readpage(struct file *file, struct page *page)
{
	struct afs_vnode *vnode;
	struct inode *inode;
	struct key *key;
	size_t len;
	off_t offset;
	int ret;

	inode = page->mapping->host;

	ASSERT(file != NULL);
	key = file->private_data;
	ASSERT(key != NULL);

	_enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index);

	vnode = AFS_FS_I(inode);

	BUG_ON(!PageLocked(page));

	ret = -ESTALE;
	if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
		goto error;

#ifdef AFS_CACHING_SUPPORT
	/* is it cached? */
	ret = cachefs_read_or_alloc_page(vnode->cache,
					 page,
					 afs_file_readpage_read_complete,
					 NULL,
					 GFP_KERNEL);
#else
	ret = -ENOBUFS;
#endif

	switch (ret) {
		/* read BIO submitted and wb-journal entry found */
	case 1:
		BUG(); // TODO - handle wb-journal match

		/* read BIO submitted (page in cache) */
	case 0:
		break;

		/* no page available in cache */
	case -ENOBUFS:
	case -ENODATA:
	default:
		offset = page->index << PAGE_CACHE_SHIFT;
		len = min_t(size_t, i_size_read(inode) - offset, PAGE_SIZE);

		/* read the contents of the file from the server into the
		 * page */
		ret = afs_vnode_fetch_data(vnode, key, offset, len, page);
		if (ret < 0) {
			if (ret == -ENOENT) {
				_debug("got NOENT from server"
				       " - marking file deleted and stale");
				set_bit(AFS_VNODE_DELETED, &vnode->flags);
				ret = -ESTALE;
			}
#ifdef AFS_CACHING_SUPPORT
			cachefs_uncache_page(vnode->cache, page);
#endif
			goto error;
		}

		SetPageUptodate(page);

#ifdef AFS_CACHING_SUPPORT
		if (cachefs_write_page(vnode->cache,
				       page,
				       afs_file_readpage_write_complete,
				       NULL,
				       GFP_KERNEL) != 0
		    ) {
			cachefs_uncache_page(vnode->cache, page);
			unlock_page(page);
		}
#else
		unlock_page(page);
#endif
	}

	_leave(" = 0");
	return 0;

error:
	SetPageError(page);
	unlock_page(page);
	_leave(" = %d", ret);
	return ret;
}
Exemplo n.º 7
0
/* Sharing code of page_mkwrite method for rhel5 and rhel6 */
static int ll_page_mkwrite0(struct vm_area_struct *vma, struct page *vmpage,
			    bool *retry)
{
	struct lu_env	   *env;
	struct cl_io	    *io;
	struct vvp_io	   *vio;
	struct cl_env_nest       nest;
	int		      result;
	sigset_t	     set;
	struct inode	     *inode;
	struct ll_inode_info     *lli;

	io = ll_fault_io_init(vma, &env,  &nest, vmpage->index, NULL);
	if (IS_ERR(io)) {
		result = PTR_ERR(io);
		goto out;
	}

	result = io->ci_result;
	if (result < 0)
		goto out_io;

	io->u.ci_fault.ft_mkwrite = 1;
	io->u.ci_fault.ft_writable = 1;

	vio = vvp_env_io(env);
	vio->u.fault.ft_vma    = vma;
	vio->u.fault.ft_vmpage = vmpage;

	set = cfs_block_sigsinv(sigmask(SIGKILL) | sigmask(SIGTERM));

	/* we grab lli_trunc_sem to exclude truncate case.
	 * Otherwise, we could add dirty pages into osc cache
	 * while truncate is on-going.
	 */
	inode = ccc_object_inode(io->ci_obj);
	lli = ll_i2info(inode);
	down_read(&lli->lli_trunc_sem);

	result = cl_io_loop(env, io);

	up_read(&lli->lli_trunc_sem);

	cfs_restore_sigs(set);

	if (result == 0) {
		struct inode *inode = file_inode(vma->vm_file);
		struct ll_inode_info *lli = ll_i2info(inode);

		lock_page(vmpage);
		if (!vmpage->mapping) {
			unlock_page(vmpage);

			/* page was truncated and lock was cancelled, return
			 * ENODATA so that VM_FAULT_NOPAGE will be returned
			 * to handle_mm_fault().
			 */
			if (result == 0)
				result = -ENODATA;
		} else if (!PageDirty(vmpage)) {
			/* race, the page has been cleaned by ptlrpcd after
			 * it was unlocked, it has to be added into dirty
			 * cache again otherwise this soon-to-dirty page won't
			 * consume any grants, even worse if this page is being
			 * transferred because it will break RPC checksum.
			 */
			unlock_page(vmpage);

			CDEBUG(D_MMAP, "Race on page_mkwrite %p/%lu, page has been written out, retry.\n",
			       vmpage, vmpage->index);

			*retry = true;
			result = -EAGAIN;
		}

		if (result == 0) {
			spin_lock(&lli->lli_lock);
			lli->lli_flags |= LLIF_DATA_MODIFIED;
			spin_unlock(&lli->lli_lock);
		}
	}

out_io:
	cl_io_fini(env, io);
	cl_env_nested_put(&nest, env);
out:
	CDEBUG(D_MMAP, "%s mkwrite with %d\n", current->comm, result);
	LASSERT(ergo(result == 0, PageLocked(vmpage)));

	return result;
}
Exemplo n.º 8
0
static void page_cache_tree_delete(struct address_space *mapping,
				   struct page *page, void *shadow)
{
	struct radix_tree_node *node;
	unsigned long index;
	unsigned int offset;
	unsigned int tag;
	void **slot;

	VM_BUG_ON(!PageLocked(page));

	__radix_tree_lookup(&mapping->page_tree, page->index, &node, &slot);

	if (shadow) {
		mapping->nrshadows++;
		/*
		 * Make sure the nrshadows update is committed before
		 * the nrpages update so that final truncate racing
		 * with reclaim does not see both counters 0 at the
		 * same time and miss a shadow entry.
		 */
		smp_wmb();
	}
	mapping->nrpages--;

	if (!node) {
		/* Clear direct pointer tags in root node */
		mapping->page_tree.gfp_mask &= __GFP_BITS_MASK;
		radix_tree_replace_slot(slot, shadow);
		return;
	}

	/* Clear tree tags for the removed page */
	index = page->index;
	offset = index & RADIX_TREE_MAP_MASK;
	for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
		if (test_bit(offset, node->tags[tag]))
			radix_tree_tag_clear(&mapping->page_tree, index, tag);
	}

	/* Delete page, swap shadow entry */
	radix_tree_replace_slot(slot, shadow);
	workingset_node_pages_dec(node);
	if (shadow)
		workingset_node_shadows_inc(node);
	else
		if (__radix_tree_delete_node(&mapping->page_tree, node))
			return;

	/*
	 * Track node that only contains shadow entries.
	 *
	 * Avoid acquiring the list_lru lock if already tracked.  The
	 * list_empty() test is safe as node->private_list is
	 * protected by mapping->tree_lock.
	 */
	if (!workingset_node_pages(node) &&
	    list_empty(&node->private_list)) {
		node->private_data = mapping;
		list_lru_add(&workingset_shadow_nodes, &node->private_list);
	}
}
Exemplo n.º 9
0
/* Sharing code of page_mkwrite method for rhel5 and rhel6 */
static int ll_page_mkwrite0(struct vm_area_struct *vma, struct page *vmpage,
                            bool *retry)
{
	struct lu_env           *env;
	struct cl_io            *io;
	struct vvp_io           *vio;
	int                      result;
	__u16			 refcheck;
	sigset_t		 set;
	struct inode             *inode;
	struct ll_inode_info     *lli;
	ENTRY;

	LASSERT(vmpage != NULL);
	env = cl_env_get(&refcheck);
	if (IS_ERR(env))
		RETURN(PTR_ERR(env));

	io = ll_fault_io_init(env, vma, vmpage->index, NULL);
	if (IS_ERR(io))
		GOTO(out, result = PTR_ERR(io));

	result = io->ci_result;
	if (result < 0)
		GOTO(out_io, result);

	io->u.ci_fault.ft_mkwrite = 1;
	io->u.ci_fault.ft_writable = 1;

	vio = vvp_env_io(env);
	vio->u.fault.ft_vma    = vma;
	vio->u.fault.ft_vmpage = vmpage;

	set = cfs_block_sigsinv(sigmask(SIGKILL) | sigmask(SIGTERM));

	inode = vvp_object_inode(io->ci_obj);
	lli = ll_i2info(inode);

	result = cl_io_loop(env, io);

	cfs_restore_sigs(set);

        if (result == 0) {
                lock_page(vmpage);
                if (vmpage->mapping == NULL) {
                        unlock_page(vmpage);

                        /* page was truncated and lock was cancelled, return
                         * ENODATA so that VM_FAULT_NOPAGE will be returned
                         * to handle_mm_fault(). */
                        if (result == 0)
                                result = -ENODATA;
                } else if (!PageDirty(vmpage)) {
                        /* race, the page has been cleaned by ptlrpcd after
                         * it was unlocked, it has to be added into dirty
                         * cache again otherwise this soon-to-dirty page won't
                         * consume any grants, even worse if this page is being
                         * transferred because it will break RPC checksum.
                         */
                        unlock_page(vmpage);

                        CDEBUG(D_MMAP, "Race on page_mkwrite %p/%lu, page has "
                               "been written out, retry.\n",
                               vmpage, vmpage->index);

                        *retry = true;
                        result = -EAGAIN;
                }

		if (result == 0)
			ll_file_set_flag(lli, LLIF_DATA_MODIFIED);
        }
        EXIT;

out_io:
	cl_io_fini(env, io);
out:
	cl_env_put(env, &refcheck);
	CDEBUG(D_MMAP, "%s mkwrite with %d\n", current->comm, result);
	LASSERT(ergo(result == 0, PageLocked(vmpage)));

	return result;
}
Exemplo n.º 10
0
int ext4_bio_write_page(struct ext4_io_submit *io,
			struct page *page,
			int len,
			struct writeback_control *wbc)
{
	struct inode *inode = page->mapping->host;
	unsigned block_start, block_end, blocksize;
	struct ext4_io_page *io_page;
	struct buffer_head *bh, *head;
	int ret = 0;

	blocksize = 1 << inode->i_blkbits;

	BUG_ON(!PageLocked(page));
	BUG_ON(PageWriteback(page));

	io_page = kmem_cache_alloc(io_page_cachep, GFP_NOFS);
	if (!io_page) {
		set_page_dirty(page);
		unlock_page(page);
		return -ENOMEM;
	}
	io_page->p_page = page;
	atomic_set(&io_page->p_count, 1);
	get_page(page);
	set_page_writeback(page);
	ClearPageError(page);

	for (bh = head = page_buffers(page), block_start = 0;
	     bh != head || !block_start;
	     block_start = block_end, bh = bh->b_this_page) {

		block_end = block_start + blocksize;
		if (block_start >= len) {
			/*
			 * Comments copied from block_write_full_page_endio:
			 *
			 * The page straddles i_size.  It must be zeroed out on
			 * each and every writepage invocation because it may
			 * be mmapped.  "A file is mapped in multiples of the
			 * page size.  For a file that is not a multiple of
			 * the  page size, the remaining memory is zeroed when
			 * mapped, and writes to that region are not written
			 * out to the file."
			 */
			zero_user_segment(page, block_start, block_end);
			clear_buffer_dirty(bh);
			set_buffer_uptodate(bh);
			continue;
		}
		clear_buffer_dirty(bh);
		ret = io_submit_add_bh(io, io_page, inode, wbc, bh);
		if (ret) {
			set_page_dirty(page);
			break;
		}
	}
	unlock_page(page);
	put_io_page(io_page);
	return ret;
}
Exemplo n.º 11
0
void bd_put_page(struct page *page)
{
    if(PageLocked(page))
        unlock_page(page);
    page_cache_release(page);
}
Exemplo n.º 12
0
static void __free_pages_ok (struct page *page, unsigned int order)
{
    unsigned long index, page_idx, mask, flags;
    free_area_t *area;
    struct page *base;
    zone_t *zone;

    if (PageLRU(page))
        lru_cache_del(page);

    if (page->buffers)
        BUG();
    if (page->mapping)
        BUG();
    if (!VALID_PAGE(page))
        BUG();
    if (PageSwapCache(page))
        BUG();
    if (PageLocked(page))
        BUG();
    if (PageLRU(page))
        BUG();
    if (PageActive(page))
        BUG();

    TRACE_MEMORY(TRACE_EV_MEMORY_PAGE_FREE, order);

    page->flags &= ~((1<<PG_referenced) | (1<<PG_dirty));

    if (current->flags & PF_FREE_PAGES)
        goto local_freelist;
back_local_freelist:

    zone = page->zone;

    mask = (~0UL) << order;
    base = zone->zone_mem_map;
    page_idx = page - base;
    if (page_idx & ~mask)
        BUG();
    index = page_idx >> (1 + order);

    area = zone->free_area + order;

    spin_lock_irqsave(&zone->lock, flags);

    zone->free_pages -= mask;

    while (mask + (1 << (MAX_ORDER-1))) {
        struct page *buddy1, *buddy2;

        if (area >= zone->free_area + MAX_ORDER)
            BUG();
        if (!__test_and_change_bit(index, area->map))
            /*
             * the buddy page is still allocated.
             */
            break;
        /*
         * Move the buddy up one level.
         */
        buddy1 = base + (page_idx ^ -mask);
        buddy2 = base + page_idx;
        if (BAD_RANGE(zone,buddy1))
            BUG();
        if (BAD_RANGE(zone,buddy2))
            BUG();

        memlist_del(&buddy1->list);
        mask <<= 1;
        area++;
        index >>= 1;
        page_idx &= mask;
    }
    memlist_add_head(&(base + page_idx)->list, &area->free_list);

    spin_unlock_irqrestore(&zone->lock, flags);
    return;

local_freelist:
    if (current->nr_local_pages)
        goto back_local_freelist;
    if (in_interrupt())
        goto back_local_freelist;

    list_add(&page->list, &current->local_pages);
    page->index = order;
    current->nr_local_pages++;
}
Exemplo n.º 13
0
/*
* "Get" data from cleancache associated with the poolid/inode/index
* that were specified when the data was put to cleanache and, if
* successful, use it to fill the specified page with data and return 0.
* The pageframe is unchanged and returns -1 if the get fails.
* Page must be locked by caller.
*/
int __cleancache_get_page(struct page *page)
{
int ret = -1;
int pool_id;
struct cleancache_filekey key = { .u.key = { 0 } };

VM_BUG_ON(!PageLocked(page));
pool_id = page->mapping->host->i_sb->cleancache_poolid;
if (pool_id < 0)
goto out;

if (cleancache_get_key(page->mapping->host, &key) < 0)
goto out;

ret = (*cleancache_ops.get_page)(pool_id, key, page->index, page);
if (ret == 0)
cleancache_succ_gets++;
else
cleancache_failed_gets++;
out:
return ret;
}
EXPORT_SYMBOL(__cleancache_get_page);

/*
* "Put" data from a page to cleancache and associate it with the
* (previously-obtained per-filesystem) poolid and the page's,
* inode and page index. Page must be locked. Note that a put_page
* always "succeeds", though a subsequent get_page may succeed or fail.
*/
void __cleancache_put_page(struct page *page)
{
int pool_id;
struct cleancache_filekey key = { .u.key = { 0 } };

VM_BUG_ON(!PageLocked(page));
pool_id = page->mapping->host->i_sb->cleancache_poolid;
if (pool_id >= 0 &&
cleancache_get_key(page->mapping->host, &key) >= 0) {
(*cleancache_ops.put_page)(pool_id, key, page->index, page);
cleancache_puts++;
}
}
EXPORT_SYMBOL(__cleancache_put_page);

/*
* Flush any data from cleancache associated with the poolid and the
* page's inode and page index so that a subsequent "get" will fail.
*/
void __cleancache_flush_page(struct address_space *mapping, struct page *page)
{
/* careful... page->mapping is NULL sometimes when this is called */
int pool_id = mapping->host->i_sb->cleancache_poolid;
struct cleancache_filekey key = { .u.key = { 0 } };

if (pool_id >= 0) {
VM_BUG_ON(!PageLocked(page));
if (cleancache_get_key(mapping->host, &key) >= 0) {
(*cleancache_ops.flush_page)(pool_id, key, page->index);
cleancache_flushes++;
}
}
}
EXPORT_SYMBOL(__cleancache_flush_page);

/*
* Flush all data from cleancache associated with the poolid and the
* mappings's inode so that all subsequent gets to this poolid/inode
* will fail.
*/
void __cleancache_flush_inode(struct address_space *mapping)
{
int pool_id = mapping->host->i_sb->cleancache_poolid;
struct cleancache_filekey key = { .u.key = { 0 } };

if (pool_id >= 0 && cleancache_get_key(mapping->host, &key) >= 0)
(*cleancache_ops.flush_inode)(pool_id, key);
}
EXPORT_SYMBOL(__cleancache_flush_inode);

/*
* Called by any cleancache-enabled filesystem at time of unmount;
* note that pool_id is surrendered and may be reutrned by a subsequent
* cleancache_init_fs or cleancache_init_shared_fs
*/
void __cleancache_flush_fs(struct super_block *sb)
{
if (sb->cleancache_poolid >= 0) {
int old_poolid = sb->cleancache_poolid;
sb->cleancache_poolid = -1;
(*cleancache_ops.flush_fs)(old_poolid);
}
}
EXPORT_SYMBOL(__cleancache_flush_fs);

#ifdef CONFIG_SYSFS

/* see Documentation/ABI/xxx/sysfs-kernel-mm-cleancache */

#define CLEANCACHE_SYSFS_RO(_name) \
static ssize_t cleancache_##_name##_show(struct kobject *kobj, \
struct kobj_attribute *attr, char *buf) \
{ \
return sprintf(buf, "%lu\n", cleancache_##_name); \
} \
static struct kobj_attribute cleancache_##_name##_attr = { \
.attr = { .name = __stringify(_name), .mode = 0444 }, \
.show = cleancache_##_name##_show, \
}

CLEANCACHE_SYSFS_RO(succ_gets);
CLEANCACHE_SYSFS_RO(failed_gets);
CLEANCACHE_SYSFS_RO(puts);
CLEANCACHE_SYSFS_RO(flushes);

static struct attribute *cleancache_attrs[] = {
&cleancache_succ_gets_attr.attr,
&cleancache_failed_gets_attr.attr,
&cleancache_puts_attr.attr,
&cleancache_flushes_attr.attr,
NULL,
};

static struct attribute_group cleancache_attr_group = {
.attrs = cleancache_attrs,
.name = "cleancache",
};

#endif /* CONFIG_SYSFS */

static int __init init_cleancache(void)
{
#ifdef CONFIG_SYSFS
int err;

err = sysfs_create_group(mm_kobj, &cleancache_attr_group);
#endif /* CONFIG_SYSFS */
return 0;
}
module_init(init_cleancache)
Exemplo n.º 14
0
static void rw_swap_page_base(int rw, unsigned long entry, struct page *page, int wait)
{
	unsigned long type, offset;
	struct swap_info_struct * p;
	int zones[PAGE_SIZE/512];
	int zones_used;
	kdev_t dev = 0;
	int block_size;

#ifdef DEBUG_SWAP
	printk ("DebugVM: %s_swap_page entry %08lx, page %p (count %d), %s\n",
		(rw == READ) ? "read" : "write", 
		entry, (char *) page_address(page), atomic_read(&page->count),
		wait ? "wait" : "nowait");
#endif

	type = SWP_TYPE(entry);
	if (type >= nr_swapfiles) {
		printk("Internal error: bad swap-device\n");
		return;
	}

	/* Don't allow too many pending pages in flight.. */
	if (atomic_read(&nr_async_pages) > pager_daemon.swap_cluster)
		wait = 1;

	p = &swap_info[type];
	offset = SWP_OFFSET(entry);
	if (offset >= p->max) {
		printk("rw_swap_page: weirdness\n");
		return;
	}
	if (p->swap_map && !p->swap_map[offset]) {
		printk(KERN_ERR "rw_swap_page: "
			"Trying to %s unallocated swap (%08lx)\n", 
			(rw == READ) ? "read" : "write", entry);
		return;
	}
	if (!(p->flags & SWP_USED)) {
		printk(KERN_ERR "rw_swap_page: "
			"Trying to swap to unused swap-device\n");
		return;
	}

	if (!PageLocked(page)) {
		printk(KERN_ERR "VM: swap page is unlocked\n");
		return;
	}

	if (PageSwapCache(page)) {
		/* Make sure we are the only process doing I/O with this swap page. */
		if (test_and_set_bit(offset, p->swap_lockmap))
		{
			struct wait_queue __wait;
			
			__wait.task = current;
			add_wait_queue(&lock_queue, &__wait);
			for (;;) {
				current->state = TASK_UNINTERRUPTIBLE;
				mb();
				if (!test_and_set_bit(offset, p->swap_lockmap))
					break;
				run_task_queue(&tq_disk);
				schedule();
			}
			current->state = TASK_RUNNING;
			remove_wait_queue(&lock_queue, &__wait);
		}

		/* 
		 * Make sure that we have a swap cache association for this
		 * page.  We need this to find which swap page to unlock once
		 * the swap IO has completed to the physical page.  If the page
		 * is not already in the cache, just overload the offset entry
		 * as if it were: we are not allowed to manipulate the inode
		 * hashing for locked pages.
		 */
		if (page->offset != entry) {
			printk ("swap entry mismatch");
			return;
		}
	}
	if (rw == READ) {
		clear_bit(PG_uptodate, &page->flags);
		kstat.pswpin++;
	} else
		kstat.pswpout++;

	atomic_inc(&page->count);
	if (p->swap_device) {
		zones[0] = offset;
		zones_used = 1;
		dev = p->swap_device;
		block_size = PAGE_SIZE;
	} else if (p->swap_file) {
		struct inode *swapf = p->swap_file->d_inode;
		int i;
		if (swapf->i_op->bmap == NULL
			&& swapf->i_op->smap != NULL){
			/*
				With MS-DOS, we use msdos_smap which returns
				a sector number (not a cluster or block number).
				It is a patch to enable the UMSDOS project.
				Other people are working on better solution.

				It sounds like ll_rw_swap_file defined
				its operation size (sector size) based on
				PAGE_SIZE and the number of blocks to read.
				So using bmap or smap should work even if
				smap will require more blocks.
			*/
			int j;
			unsigned int block = offset << 3;

			for (i=0, j=0; j< PAGE_SIZE ; i++, j += 512){
				if (!(zones[i] = swapf->i_op->smap(swapf,block++))) {
					printk("rw_swap_page: bad swap file\n");
					return;
				}
			}
			block_size = 512;
		}else{
			int j;
			unsigned int block = offset
				<< (PAGE_SHIFT - swapf->i_sb->s_blocksize_bits);

			block_size = swapf->i_sb->s_blocksize;
			for (i=0, j=0; j< PAGE_SIZE ; i++, j += block_size)
				if (!(zones[i] = bmap(swapf,block++))) {
					printk("rw_swap_page: bad swap file\n");
					return;
				}
			zones_used = i;
			dev = swapf->i_dev;
		}
	} else {
		printk(KERN_ERR "rw_swap_page: no swap file or device\n");
		/* Do some cleaning up so if this ever happens we can hopefully
		 * trigger controlled shutdown.
		 */
		if (PageSwapCache(page)) {
			if (!test_and_clear_bit(offset,p->swap_lockmap))
				printk("swap_after_unlock_page: lock already cleared\n");
			wake_up(&lock_queue);
		}
		atomic_dec(&page->count);
		return;
	}
 	if (!wait) {
 		set_bit(PG_decr_after, &page->flags);
 		atomic_inc(&nr_async_pages);
 	}
 	if (PageSwapCache(page)) {
 		/* only lock/unlock swap cache pages! */
 		set_bit(PG_swap_unlock_after, &page->flags);
 	}
 	set_bit(PG_free_after, &page->flags);

 	/* block_size == PAGE_SIZE/zones_used */
 	brw_page(rw, page, dev, zones, block_size, 0);
 
 	/* Note! For consistency we do all of the logic,
 	 * decrementing the page count, and unlocking the page in the
 	 * swap lock map - in the IO completion handler.
 	 */
 	if (!wait) 
 		return;
 	wait_on_page(page);
	/* This shouldn't happen, but check to be sure. */
	if (atomic_read(&page->count) == 0)
		printk(KERN_ERR "rw_swap_page: page unused while waiting!\n");

#ifdef DEBUG_SWAP
	printk ("DebugVM: %s_swap_page finished on page %p (count %d)\n",
		(rw == READ) ? "read" : "write", 
		(char *) page_adddress(page), 
		atomic_read(&page->count));
#endif
}
Exemplo n.º 15
0
int ext4_bio_write_page(struct ext4_io_submit *io,
			struct page *page,
			int len,
			struct writeback_control *wbc)
{
	struct inode *inode = page->mapping->host;
	unsigned block_start, block_end, blocksize;
	struct ext4_io_page *io_page;
	struct buffer_head *bh, *head;
	int ret = 0;

	blocksize = 1 << inode->i_blkbits;

	BUG_ON(!PageLocked(page));
	BUG_ON(PageWriteback(page));

	io_page = kmem_cache_alloc(io_page_cachep, GFP_NOFS);
	if (!io_page) {
		set_page_dirty(page);
		unlock_page(page);
		return -ENOMEM;
	}
	io_page->p_page = page;
	atomic_set(&io_page->p_count, 1);
	get_page(page);
	set_page_writeback(page);
	ClearPageError(page);

	for (bh = head = page_buffers(page), block_start = 0;
	     bh != head || !block_start;
	     block_start = block_end, bh = bh->b_this_page) {

		block_end = block_start + blocksize;
		if (block_start >= len) {
			clear_buffer_dirty(bh);
			set_buffer_uptodate(bh);
			continue;
		}
		clear_buffer_dirty(bh);
		ret = io_submit_add_bh(io, io_page, inode, wbc, bh);
		if (ret) {
			/*
			 * We only get here on ENOMEM.  Not much else
			 * we can do but mark the page as dirty, and
			 * better luck next time.
			 */
			set_page_dirty(page);
			break;
		}
	}
	unlock_page(page);
	/*
	 * If the page was truncated before we could do the writeback,
	 * or we had a memory allocation error while trying to write
	 * the first buffer head, we won't have submitted any pages for
	 * I/O.  In that case we need to make sure we've cleared the
	 * PageWriteback bit from the page to prevent the system from
	 * wedging later on.
	 */
	put_io_page(io_page);
	return ret;
}
Exemplo n.º 16
0
/*
 * "Get" data from cleancache associated with the poolid/inode/index
 * that were specified when the data was put to cleanache and, if
 * successful, use it to fill the specified page with data and return 0.
 * The pageframe is unchanged and returns -1 if the get fails.
 * Page must be locked by caller.
 */
int __cleancache_get_page(struct page *page)
{
	int ret = -1;
	int pool_id;
	struct cleancache_filekey key = { .u.key = { 0 } };

	VM_BUG_ON(!PageLocked(page));
	pool_id = page->mapping->host->i_sb->cleancache_poolid;
	if (pool_id < 0)
		goto out;

	if (cleancache_get_key(page->mapping->host, &key) < 0)
		goto out;

	ret = (*cleancache_ops.get_page)(pool_id, key, page->index, page);
	if (ret == 0)
		cleancache_succ_gets++;
	else
		cleancache_failed_gets++;
out:
	return ret;
}
EXPORT_SYMBOL(__cleancache_get_page);

/*
 * "Put" data from a page to cleancache and associate it with the
 * (previously-obtained per-filesystem) poolid and the page's,
 * inode and page index.  Page must be locked.  Note that a put_page
 * always "succeeds", though a subsequent get_page may succeed or fail.
 */
void __cleancache_put_page(struct page *page)
{
	int pool_id;
	struct cleancache_filekey key = { .u.key = { 0 } };

	VM_BUG_ON(!PageLocked(page));
	pool_id = page->mapping->host->i_sb->cleancache_poolid;
	if (pool_id >= 0 &&
	      cleancache_get_key(page->mapping->host, &key) >= 0) {
		(*cleancache_ops.put_page)(pool_id, key, page->index, page);
		cleancache_puts++;
	}
}
EXPORT_SYMBOL(__cleancache_put_page);

/*
 * Invalidate any data from cleancache associated with the poolid and the
 * page's inode and page index so that a subsequent "get" will fail.
 */
void __cleancache_invalidate_page(struct address_space *mapping,
					struct page *page)
{
	/* careful... page->mapping is NULL sometimes when this is called */
	int pool_id = mapping->host->i_sb->cleancache_poolid;
	struct cleancache_filekey key = { .u.key = { 0 } };

	if (pool_id >= 0) {
		VM_BUG_ON(!PageLocked(page));
		if (cleancache_get_key(mapping->host, &key) >= 0) {
			(*cleancache_ops.invalidate_page)(pool_id,
							  key, page->index);
			cleancache_invalidates++;
		}
	}
}
EXPORT_SYMBOL(__cleancache_invalidate_page);

/*
 * Invalidate all data from cleancache associated with the poolid and the
 * mappings's inode so that all subsequent gets to this poolid/inode
 * will fail.
 */
void __cleancache_invalidate_inode(struct address_space *mapping)
{
	int pool_id = mapping->host->i_sb->cleancache_poolid;
	struct cleancache_filekey key = { .u.key = { 0 } };

	if (pool_id >= 0 && cleancache_get_key(mapping->host, &key) >= 0)
		(*cleancache_ops.invalidate_inode)(pool_id, key);
}
EXPORT_SYMBOL(__cleancache_invalidate_inode);

/*
 * Called by any cleancache-enabled filesystem at time of unmount;
 * note that pool_id is surrendered and may be reutrned by a subsequent
 * cleancache_init_fs or cleancache_init_shared_fs
 */
void __cleancache_invalidate_fs(struct super_block *sb)
{
	if (sb->cleancache_poolid >= 0) {
		int old_poolid = sb->cleancache_poolid;
		sb->cleancache_poolid = -1;
		(*cleancache_ops.invalidate_fs)(old_poolid);
	}
}
EXPORT_SYMBOL(__cleancache_invalidate_fs);

static int __init init_cleancache(void)
{
#ifdef CONFIG_DEBUG_FS
	struct dentry *root = debugfs_create_dir("cleancache", NULL);
	if (root == NULL)
		return -ENXIO;
	debugfs_create_u64("succ_gets", S_IRUGO, root, &cleancache_succ_gets);
	debugfs_create_u64("failed_gets", S_IRUGO,
				root, &cleancache_failed_gets);
	debugfs_create_u64("puts", S_IRUGO, root, &cleancache_puts);
	debugfs_create_u64("invalidates", S_IRUGO,
				root, &cleancache_invalidates);
#endif
	return 0;
}
module_init(init_cleancache)
Exemplo n.º 17
0
int ext4_bio_write_page(struct ext4_io_submit *io,
			struct page *page,
			int len,
			struct writeback_control *wbc)
{
	struct inode *inode = page->mapping->host;
	unsigned block_start, block_end, blocksize;
	struct ext4_io_page *io_page;
	struct buffer_head *bh, *head;
	int ret = 0;

	blocksize = 1 << inode->i_blkbits;

	BUG_ON(!PageLocked(page));
	BUG_ON(PageWriteback(page));

	io_page = kmem_cache_alloc(io_page_cachep, GFP_NOFS);
	if (!io_page) {
		set_page_dirty(page);
		unlock_page(page);
		return -ENOMEM;
	}
	io_page->p_page = page;
	atomic_set(&io_page->p_count, 1);
	get_page(page);
	set_page_writeback(page);
	ClearPageError(page);

	/*
	 * Comments copied from block_write_full_page_endio:
	 *
	 * The page straddles i_size.  It must be zeroed out on each and every
	 * writepage invocation because it may be mmapped.  "A file is mapped
	 * in multiples of the page size.  For a file that is not a multiple of
	 * the page size, the remaining memory is zeroed when mapped, and
	 * writes to that region are not written out to the file."
	 */
	if (len < PAGE_CACHE_SIZE)
		zero_user_segment(page, len, PAGE_CACHE_SIZE);

	for (bh = head = page_buffers(page), block_start = 0;
	     bh != head || !block_start;
	     block_start = block_end, bh = bh->b_this_page) {

		block_end = block_start + blocksize;
		if (block_start >= len) {
			clear_buffer_dirty(bh);
			set_buffer_uptodate(bh);
			continue;
		}
		clear_buffer_dirty(bh);
		ret = io_submit_add_bh(io, io_page, inode, wbc, bh);
		if (ret) {
			/*
			 * We only get here on ENOMEM.  Not much else
			 * we can do but mark the page as dirty, and
			 * better luck next time.
			 */
			set_page_dirty(page);
			break;
		}
	}
	unlock_page(page);
	/*
	 * If the page was truncated before we could do the writeback,
	 * or we had a memory allocation error while trying to write
	 * the first buffer head, we won't have submitted any pages for
	 * I/O.  In that case we need to make sure we've cleared the
	 * PageWriteback bit from the page to prevent the system from
	 * wedging later on.
	 */
	put_io_page(io_page);
	return ret;
}
Exemplo n.º 18
0
/*
 * Try to free buffers if "page" has them.
 */
static int
remap_preparepage(struct page *page, int fastmode)
{
    struct address_space *mapping;
    int waitcnt = fastmode ? 0 : 10;

    BUG_ON(!PageLocked(page));

    mapping = page_mapping(page);

    if (PageWriteback(page) && !PagePrivate(page) && !PageSwapCache(page)) {
        printk("remap: mapping %p page %p\n", page->mapping, page);
        return -REMAPPREP_WB;
    }

    if (PageWriteback(page))
        wait_on_page_writeback(page);

    if (PagePrivate(page)) {
#ifdef DEBUG_MSG
        printk("rmap: process page with buffers...\n");
#endif
        /* XXX copied from shrink_list() */
        if (PageDirty(page) &&
                is_page_cache_freeable(page) &&
                mapping != NULL &&
                mapping->a_ops->writepage != NULL) {
            spin_lock_irq(&mapping->tree_lock);
            if (clear_page_dirty_for_io(page)) {
                int res;
                struct writeback_control wbc = {
                    .sync_mode = WB_SYNC_NONE,
                    .nr_to_write = SWAP_CLUSTER_MAX,
                    .nonblocking = 1,
                    .for_reclaim = 1,
                };

                spin_unlock_irq(&mapping->tree_lock);

                SetPageReclaim(page);
                res = mapping->a_ops->writepage(page, &wbc);

                if (res < 0)
                    /* not implemented. help */
                    BUG();
                if (res == WRITEPAGE_ACTIVATE) {
                    ClearPageReclaim(page);
                    return -REMAPPREP_WB;
                }
                if (!PageWriteback(page)) {
                    /* synchronous write or broken a_ops? */
                    ClearPageReclaim(page);
                }
                lock_page(page);
                if (!PagePrivate(page))
                    return 0;
            } else
                spin_unlock_irq(&mapping->tree_lock);
        }

        while (1) {
            if (try_to_release_page(page, GFP_KERNEL))
                break;
            if (!waitcnt)
                return -REMAPPREP_BUFFER;
            msleep(10);
            waitcnt--;
            if (!waitcnt)
                print_buffer(page);
        }
    }
Exemplo n.º 19
0
/*
 * Modify inode page cache in such way:
 * have - blocks with b_blocknr equal to oldb...oldb+count-1
 * get - blocks with b_blocknr equal to newb...newb+count-1
 * also we suppose that oldb...oldb+count-1 blocks
 * situated at the end of file.
 *
 * We can come here from ufs_writepage or ufs_prepare_write,
 * locked_page is argument of these functions, so we already lock it.
 */
static void ufs_change_blocknr(struct inode *inode, sector_t beg,
			       unsigned int count, sector_t oldb,
			       sector_t newb, struct page *locked_page)
{
	const unsigned blks_per_page =
		1 << (PAGE_CACHE_SHIFT - inode->i_blkbits);
	const unsigned mask = blks_per_page - 1;
	struct address_space * const mapping = inode->i_mapping;
	pgoff_t index, cur_index, last_index;
	unsigned pos, j, lblock;
	sector_t end, i;
	struct page *page;
	struct buffer_head *head, *bh;

	UFSD("ENTER, ino %lu, count %u, oldb %llu, newb %llu\n",
	      inode->i_ino, count,
	     (unsigned long long)oldb, (unsigned long long)newb);

	BUG_ON(!locked_page);
	BUG_ON(!PageLocked(locked_page));

	cur_index = locked_page->index;
	end = count + beg;
	last_index = end >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
	for (i = beg; i < end; i = (i | mask) + 1) {
		index = i >> (PAGE_CACHE_SHIFT - inode->i_blkbits);

		if (likely(cur_index != index)) {
			page = ufs_get_locked_page(mapping, index);
			if (!page)/* it was truncated */
				continue;
			if (IS_ERR(page)) {/* or EIO */
				ufs_error(inode->i_sb, __func__,
					  "read of page %llu failed\n",
					  (unsigned long long)index);
				continue;
			}
		} else
			page = locked_page;

		head = page_buffers(page);
		bh = head;
		pos = i & mask;
		for (j = 0; j < pos; ++j)
			bh = bh->b_this_page;


		if (unlikely(index == last_index))
			lblock = end & mask;
		else
			lblock = blks_per_page;

		do {
			if (j >= lblock)
				break;
			pos = (i - beg) + j;

			if (!buffer_mapped(bh))
					map_bh(bh, inode->i_sb, oldb + pos);
			if (!buffer_uptodate(bh)) {
				ll_rw_block(READ, 1, &bh);
				wait_on_buffer(bh);
				if (!buffer_uptodate(bh)) {
					ufs_error(inode->i_sb, __func__,
						  "read of block failed\n");
					break;
				}
			}

			UFSD(" change from %llu to %llu, pos %u\n",
			     (unsigned long long)(pos + oldb),
			     (unsigned long long)(pos + newb), pos);

			bh->b_blocknr = newb + pos;
			unmap_underlying_metadata(bh->b_bdev,
						  bh->b_blocknr);
			mark_buffer_dirty(bh);
			++j;
			bh = bh->b_this_page;
		} while (bh != head);

		if (likely(cur_index != index))
			ufs_put_locked_page(page);
 	}
	UFSD("EXIT\n");
}
Exemplo n.º 20
0
static int vvp_io_fault_start(const struct lu_env *env,
                              const struct cl_io_slice *ios)
{
	struct vvp_io       *vio     = cl2vvp_io(env, ios);
	struct cl_io        *io      = ios->cis_io;
	struct cl_object    *obj     = io->ci_obj;
	struct inode        *inode   = ccc_object_inode(obj);
	struct cl_fault_io  *fio     = &io->u.ci_fault;
	struct vvp_fault_io *cfio    = &vio->u.fault;
	loff_t               offset;
	int                  result  = 0;
	struct page          *vmpage  = NULL;
	struct cl_page      *page;
	loff_t               size;
	pgoff_t              last; /* last page in a file data region */

        if (fio->ft_executable &&
            LTIME_S(inode->i_mtime) != vio->u.fault.ft_mtime)
                CWARN("binary "DFID
                      " changed while waiting for the page fault lock\n",
                      PFID(lu_object_fid(&obj->co_lu)));

        /* offset of the last byte on the page */
        offset = cl_offset(obj, fio->ft_index + 1) - 1;
        LASSERT(cl_index(obj, offset) == fio->ft_index);
        result = ccc_prep_size(env, obj, io, 0, offset + 1, NULL);
        if (result != 0)
                return result;

	/* must return locked page */
	if (fio->ft_mkwrite) {
		LASSERT(cfio->ft_vmpage != NULL);
		lock_page(cfio->ft_vmpage);
	} else {
		result = vvp_io_kernel_fault(cfio);
		if (result != 0)
			return result;
	}

	vmpage = cfio->ft_vmpage;
	LASSERT(PageLocked(vmpage));

	if (OBD_FAIL_CHECK(OBD_FAIL_LLITE_FAULT_TRUNC_RACE))
		ll_invalidate_page(vmpage);

	size = i_size_read(inode);
        /* Though we have already held a cl_lock upon this page, but
         * it still can be truncated locally. */
	if (unlikely((vmpage->mapping != inode->i_mapping) ||
		     (page_offset(vmpage) > size))) {
                CDEBUG(D_PAGE, "llite: fault and truncate race happened!\n");

                /* return +1 to stop cl_io_loop() and ll_fault() will catch
                 * and retry. */
                GOTO(out, result = +1);
        }


	if (fio->ft_mkwrite ) {
		pgoff_t last_index;
		/*
		 * Capture the size while holding the lli_trunc_sem from above
		 * we want to make sure that we complete the mkwrite action
		 * while holding this lock. We need to make sure that we are
		 * not past the end of the file.
		 */
		last_index = cl_index(obj, size - 1);
		if (last_index < fio->ft_index) {
			CDEBUG(D_PAGE,
				"llite: mkwrite and truncate race happened: "
				"%p: 0x%lx 0x%lx\n",
				vmpage->mapping,fio->ft_index,last_index);
			/*
			 * We need to return if we are
			 * passed the end of the file. This will propagate
			 * up the call stack to ll_page_mkwrite where
			 * we will return VM_FAULT_NOPAGE. Any non-negative
			 * value returned here will be silently
			 * converted to 0. If the vmpage->mapping is null
			 * the error code would be converted back to ENODATA
			 * in ll_page_mkwrite0. Thus we return -ENODATA
			 * to handle both cases
			 */
			GOTO(out, result = -ENODATA);
		}
	}

        page = cl_page_find(env, obj, fio->ft_index, vmpage, CPT_CACHEABLE);
        if (IS_ERR(page))
                GOTO(out, result = PTR_ERR(page));

        /* if page is going to be written, we should add this page into cache
         * earlier. */
        if (fio->ft_mkwrite) {
                wait_on_page_writeback(vmpage);
                if (set_page_dirty(vmpage)) {
                        struct ccc_page *cp;

                        /* vvp_page_assume() calls wait_on_page_writeback(). */
                        cl_page_assume(env, io, page);

                        cp = cl2ccc_page(cl_page_at(page, &vvp_device_type));
                        vvp_write_pending(cl2ccc(obj), cp);

                        /* Do not set Dirty bit here so that in case IO is
                         * started before the page is really made dirty, we
                         * still have chance to detect it. */
                        result = cl_page_cache_add(env, io, page, CRT_WRITE);
			LASSERT(cl_page_is_owned(page, io));

			vmpage = NULL;
			if (result < 0) {
				cl_page_unmap(env, io, page);
				cl_page_discard(env, io, page);
				cl_page_disown(env, io, page);

				cl_page_put(env, page);

				/* we're in big trouble, what can we do now? */
				if (result == -EDQUOT)
					result = -ENOSPC;
				GOTO(out, result);
			} else
				cl_page_disown(env, io, page);
		}
	}

	last = cl_index(obj, size - 1);
	/*
	 * The ft_index is only used in the case of
	 * a mkwrite action. We need to check
	 * our assertions are correct, since
	 * we should have caught this above
	 */
	LASSERT(!fio->ft_mkwrite || fio->ft_index <= last);
        if (fio->ft_index == last)
                /*
                 * Last page is mapped partially.
                 */
                fio->ft_nob = size - cl_offset(obj, fio->ft_index);
        else
                fio->ft_nob = cl_page_size(obj);

        lu_ref_add(&page->cp_reference, "fault", io);
        fio->ft_page = page;
        EXIT;

out:
	/* return unlocked vmpage to avoid deadlocking */
	if (vmpage != NULL)
		unlock_page(vmpage);
	cfio->fault.ft_flags &= ~VM_FAULT_LOCKED;
	return result;
}
Exemplo n.º 21
0
static int ext4_destroy_inline_data_nolock(handle_t *handle,
					   struct inode *inode)
{
	struct ext4_inode_info *ei = EXT4_I(inode);
	struct ext4_xattr_ibody_find is = {
		.s = { .not_found = 0, },
	};
	struct ext4_xattr_info i = {
		.name_index = EXT4_XATTR_INDEX_SYSTEM,
		.name = EXT4_XATTR_SYSTEM_DATA,
		.value = NULL,
		.value_len = 0,
	};
	int error;

	if (!ei->i_inline_off)
		return 0;

	error = ext4_get_inode_loc(inode, &is.iloc);
	if (error)
		return error;

	error = ext4_xattr_ibody_find(inode, &i, &is);
	if (error)
		goto out;

	BUFFER_TRACE(is.iloc.bh, "get_write_access");
	error = ext4_journal_get_write_access(handle, is.iloc.bh);
	if (error)
		goto out;

	error = ext4_xattr_ibody_inline_set(handle, inode, &i, &is);
	if (error)
		goto out;

	memset((void *)ext4_raw_inode(&is.iloc)->i_block,
		0, EXT4_MIN_INLINE_DATA_SIZE);

	if (ext4_has_feature_extents(inode->i_sb)) {
		if (S_ISDIR(inode->i_mode) ||
		    S_ISREG(inode->i_mode) || S_ISLNK(inode->i_mode)) {
			ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
			ext4_ext_tree_init(handle, inode);
		}
	}
	ext4_clear_inode_flag(inode, EXT4_INODE_INLINE_DATA);

	get_bh(is.iloc.bh);
	error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);

	EXT4_I(inode)->i_inline_off = 0;
	EXT4_I(inode)->i_inline_size = 0;
	ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
out:
	brelse(is.iloc.bh);
	if (error == -ENODATA)
		error = 0;
	return error;
}

static int ext4_read_inline_page(struct inode *inode, struct page *page)
{
	void *kaddr;
	int ret = 0;
	size_t len;
	struct ext4_iloc iloc;

	BUG_ON(!PageLocked(page));
	BUG_ON(!ext4_has_inline_data(inode));
	BUG_ON(page->index);

	if (!EXT4_I(inode)->i_inline_off) {
		ext4_warning(inode->i_sb, "inode %lu doesn't have inline data.",
			     inode->i_ino);
		goto out;
	}

	ret = ext4_get_inode_loc(inode, &iloc);
	if (ret)
		goto out;

	len = min_t(size_t, ext4_get_inline_size(inode), i_size_read(inode));
	kaddr = kmap_atomic(page);
	ret = ext4_read_inline_data(inode, kaddr, len, &iloc);
	flush_dcache_page(page);
	kunmap_atomic(kaddr);
	zero_user_segment(page, len, PAGE_CACHE_SIZE);
	SetPageUptodate(page);
	brelse(iloc.bh);

out:
	return ret;
}
Exemplo n.º 22
0
static void kcdfsd_process_request(void){
  struct list_head * tmp;
  struct kcdfsd_req * req;
  struct page * page;
  struct inode * inode;
  unsigned request;
  
  while (!list_empty (&kcdfsd_req_list)){
    /* Grab the next entry from the beginning of the list */
    tmp = kcdfsd_req_list.next;
    req = list_entry (tmp, struct kcdfsd_req, req_list);
    list_del (tmp);
    page = req->page;
    inode = req->dentry->d_inode;
    request = req->request_type;
    if (!PageLocked(page))
#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,12))
      PAGE_BUG(page);
#else
      BUG();
#endif

    switch (request){
      case CDDA_REQUEST:
      case CDDA_RAW_REQUEST:
        {
          cd *this_cd = cdfs_info (inode->i_sb);
          char *p;
          track_info *this_track = &(this_cd->track[inode->i_ino]);
          cdfs_cdda_file_read (inode,
                               p = (char *) kmap (page),
                               1 << PAGE_CACHE_SHIFT,
                               (page->index << PAGE_CACHE_SHIFT) +
                               ((this_track->avi) ? this_track->
                                avi_offset : 0),
                               (request == CDDA_RAW_REQUEST));
          if ((this_track->avi) && (this_track->avi_swab)){
              int k;
              for (k=0; k<(1 << PAGE_CACHE_SHIFT); k+=2){
                  char c;
                  c = p[k];
                  p[k] = p[k + 1];
                  p[k + 1] = c;
                }
            }
        }
        break;
      case CDXA_REQUEST:
        cdfs_copy_from_cdXA(inode->i_sb,
                            inode->i_ino,
                            page->index << PAGE_CACHE_SHIFT,
                            (page->index + 1) << PAGE_CACHE_SHIFT,
                            (char *)kmap(page));
        break;
      case CDDATA_REQUEST:
        cdfs_copy_from_cddata(inode->i_sb,
                              inode->i_ino,
                              page->index << PAGE_CACHE_SHIFT,
                              (page->index + 1) << PAGE_CACHE_SHIFT,
                              (char *)kmap(page));
        break;
      case CDHFS_REQUEST:
        cdfs_copy_from_cdhfs(inode->i_sb,
                             inode->i_ino,
                             page->index << PAGE_CACHE_SHIFT,
                             (page->index + 1) << PAGE_CACHE_SHIFT,
                             (char *)kmap(page));
        break;
    }

    SetPageUptodate (page);
    kunmap (page);
    unlock_page (page);
    kfree (req);
  }
}
Exemplo n.º 23
0
/*
 * AFS read page from file (or symlink)
 */
static int afs_file_readpage(struct file *file, struct page *page)
{
	struct afs_rxfs_fetch_descriptor desc;
#ifdef AFS_CACHING_SUPPORT
	struct cachefs_page *pageio;
#endif
	struct afs_vnode *vnode;
	struct inode *inode;
	int ret;

	inode = page->mapping->host;

	_enter("{%lu},{%lu}", inode->i_ino, page->index);

	vnode = AFS_FS_I(inode);

	BUG_ON(!PageLocked(page));

	ret = -ESTALE;
	if (vnode->flags & AFS_VNODE_DELETED)
		goto error;

#ifdef AFS_CACHING_SUPPORT
	ret = cachefs_page_get_private(page, &pageio, GFP_NOIO);
	if (ret < 0)
		goto error;

	/* is it cached? */
	ret = cachefs_read_or_alloc_page(vnode->cache,
					 page,
					 afs_file_readpage_read_complete,
					 NULL,
					 GFP_KERNEL);
#else
	ret = -ENOBUFS;
#endif

	switch (ret) {
		/* read BIO submitted and wb-journal entry found */
	case 1:
		BUG(); // TODO - handle wb-journal match

		/* read BIO submitted (page in cache) */
	case 0:
		break;

		/* no page available in cache */
	case -ENOBUFS:
	case -ENODATA:
	default:
		desc.fid	= vnode->fid;
		desc.offset	= page->index << PAGE_CACHE_SHIFT;
		desc.size	= min((size_t) (inode->i_size - desc.offset),
				      (size_t) PAGE_SIZE);
		desc.buffer	= kmap(page);

		clear_page(desc.buffer);

		/* read the contents of the file from the server into the
		 * page */
		ret = afs_vnode_fetch_data(vnode, &desc);
		kunmap(page);
		if (ret < 0) {
			if (ret==-ENOENT) {
				_debug("got NOENT from server"
				       " - marking file deleted and stale");
				vnode->flags |= AFS_VNODE_DELETED;
				ret = -ESTALE;
			}

#ifdef AFS_CACHING_SUPPORT
			cachefs_uncache_page(vnode->cache, page);
#endif
			goto error;
		}

		SetPageUptodate(page);

#ifdef AFS_CACHING_SUPPORT
		if (cachefs_write_page(vnode->cache,
				       page,
				       afs_file_readpage_write_complete,
				       NULL,
				       GFP_KERNEL) != 0
		    ) {
			cachefs_uncache_page(vnode->cache, page);
			unlock_page(page);
		}
#else
		unlock_page(page);
#endif
	}

	_leave(" = 0");
	return 0;

 error:
	SetPageError(page);
	unlock_page(page);

	_leave(" = %d", ret);
	return ret;

} /* end afs_file_readpage() */
Exemplo n.º 24
0
/* Two pass sync: first using WB_SYNC_NONE, then WB_SYNC_ALL */
static int nfs_write_mapping(struct address_space *mapping, int how)
{
	struct writeback_control wbc = {
		.bdi = mapping->backing_dev_info,
		.sync_mode = WB_SYNC_ALL,
		.nr_to_write = LONG_MAX,
		.range_start = 0,
		.range_end = LLONG_MAX,
	};

	return __nfs_write_mapping(mapping, &wbc, how);
}

/*
 * flush the inode to disk.
 */
int nfs_wb_all(struct inode *inode)
{
	return nfs_write_mapping(inode->i_mapping, 0);
}

int nfs_wb_nocommit(struct inode *inode)
{
	return nfs_write_mapping(inode->i_mapping, FLUSH_NOCOMMIT);
}

int nfs_wb_page_cancel(struct inode *inode, struct page *page)
{
	struct nfs_page *req;
	loff_t range_start = page_offset(page);
	loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
	struct writeback_control wbc = {
		.bdi = page->mapping->backing_dev_info,
		.sync_mode = WB_SYNC_ALL,
		.nr_to_write = LONG_MAX,
		.range_start = range_start,
		.range_end = range_end,
	};
	int ret = 0;

	BUG_ON(!PageLocked(page));
	for (;;) {
		req = nfs_page_find_request(page);
		if (req == NULL)
			goto out;
		if (test_bit(PG_CLEAN, &req->wb_flags)) {
			nfs_release_request(req);
			break;
		}
		if (nfs_lock_request_dontget(req)) {
			nfs_inode_remove_request(req);
			/*
			 * In case nfs_inode_remove_request has marked the
			 * page as being dirty
			 */
			cancel_dirty_page(page, PAGE_CACHE_SIZE);
			nfs_unlock_request(req);
			break;
		}
		ret = nfs_wait_on_request(req);
		if (ret < 0)
			goto out;
	}
	if (!PagePrivate(page))
		return 0;
	ret = nfs_sync_mapping_wait(page->mapping, &wbc, FLUSH_INVALIDATE);
out:
	return ret;
}

static int nfs_wb_page_priority(struct inode *inode, struct page *page,
				int how)
{
	loff_t range_start = page_offset(page);
	loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
	struct writeback_control wbc = {
		.bdi = page->mapping->backing_dev_info,
		.sync_mode = WB_SYNC_ALL,
		.nr_to_write = LONG_MAX,
		.range_start = range_start,
		.range_end = range_end,
	};
	int ret;

	do {
		if (clear_page_dirty_for_io(page)) {
			ret = nfs_writepage_locked(page, &wbc);
			if (ret < 0)
				goto out_error;
		} else if (!PagePrivate(page))
			break;
		ret = nfs_sync_mapping_wait(page->mapping, &wbc, how);
		if (ret < 0)
			goto out_error;
	} while (PagePrivate(page));
	return 0;
out_error:
	__mark_inode_dirty(inode, I_DIRTY_PAGES);
	return ret;
}

/*
 * Write back all requests on one page - we do this before reading it.
 */
int nfs_wb_page(struct inode *inode, struct page* page)
{
	return nfs_wb_page_priority(inode, page, FLUSH_STABLE);
}

#ifdef CONFIG_MIGRATION
int nfs_migrate_page(struct address_space *mapping, struct page *newpage,
		struct page *page)
{
	struct nfs_page *req;
	int ret;

	if (PageFsCache(page))
		nfs_fscache_release_page(page, GFP_KERNEL);

	req = nfs_find_and_lock_request(page);
	ret = PTR_ERR(req);
	if (IS_ERR(req))
		goto out;

	ret = migrate_page(mapping, newpage, page);
	if (!req)
		goto out;
	if (ret)
		goto out_unlock;
	page_cache_get(newpage);
	req->wb_page = newpage;
	SetPagePrivate(newpage);
	set_page_private(newpage, page_private(page));
	ClearPagePrivate(page);
	set_page_private(page, 0);
	page_cache_release(page);
out_unlock:
	nfs_clear_page_tag_locked(req);
	nfs_release_request(req);
out:
	return ret;
}
#endif

int __init nfs_init_writepagecache(void)
{
	nfs_wdata_cachep = kmem_cache_create("nfs_write_data",
					     sizeof(struct nfs_write_data),
					     0, SLAB_HWCACHE_ALIGN,
					     NULL);
	if (nfs_wdata_cachep == NULL)
		return -ENOMEM;

	nfs_wdata_mempool = mempool_create_slab_pool(MIN_POOL_WRITE,
						     nfs_wdata_cachep);
	if (nfs_wdata_mempool == NULL)
		return -ENOMEM;

	nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT,
						      nfs_wdata_cachep);
	if (nfs_commit_mempool == NULL)
		return -ENOMEM;

	/*
	 * NFS congestion size, scale with available memory.
	 *
	 *  64MB:    8192k
	 * 128MB:   11585k
	 * 256MB:   16384k
	 * 512MB:   23170k
	 *   1GB:   32768k
	 *   2GB:   46340k
	 *   4GB:   65536k
	 *   8GB:   92681k
	 *  16GB:  131072k
	 *
	 * This allows larger machines to have larger/more transfers.
	 * Limit the default to 256M
	 */
	nfs_congestion_kb = (16*int_sqrt(totalram_pages)) << (PAGE_SHIFT-10);
	if (nfs_congestion_kb > 256*1024)
		nfs_congestion_kb = 256*1024;

	return 0;
}

void nfs_destroy_writepagecache(void)
{
	mempool_destroy(nfs_commit_mempool);
	mempool_destroy(nfs_wdata_mempool);
	kmem_cache_destroy(nfs_wdata_cachep);
}
Exemplo n.º 25
0
/**
 * write_one_page - write out a single page and optionally wait on I/O
 * @page: the page to write
 * @wait: if true, wait on writeout
 *
 * The page must be locked by the caller and will be unlocked upon return.
 *
 * write_one_page() returns a negative error code if I/O failed.
 */
int write_one_page(struct page *page, int wait)
{
	struct address_space *mapping = page->mapping;
	int ret = 0;
	struct writeback_control wbc = {
		.sync_mode = WB_SYNC_ALL,
		.nr_to_write = 1,
	};

	BUG_ON(!PageLocked(page));

	if (wait)
		wait_on_page_writeback(page);

	if (clear_page_dirty_for_io(page)) {
		page_cache_get(page);
		ret = mapping->a_ops->writepage(page, &wbc);
		if (ret == 0 && wait) {
			wait_on_page_writeback(page);
			if (PageError(page))
				ret = -EIO;
		}
		page_cache_release(page);
	} else {
		unlock_page(page);
	}
	return ret;
}
EXPORT_SYMBOL(write_one_page);

/*
 * For address_spaces which do not use buffers nor write back.
 */
int __set_page_dirty_no_writeback(struct page *page)
{
	if (!PageDirty(page))
		SetPageDirty(page);
	return 0;
}

/*
 * Helper function for set_page_dirty family.
 * NOTE: This relies on being atomic wrt interrupts.
 */
void account_page_dirtied(struct page *page, struct address_space *mapping)
{
	if (mapping_cap_account_dirty(mapping)) {
		__inc_zone_page_state(page, NR_FILE_DIRTY);
		__inc_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE);
		task_dirty_inc(current);
		task_io_account_write(PAGE_CACHE_SIZE);
	}
}

/*
 * For address_spaces which do not use buffers.  Just tag the page as dirty in
 * its radix tree.
 *
 * This is also used when a single buffer is being dirtied: we want to set the
 * page dirty in that case, but not all the buffers.  This is a "bottom-up"
 * dirtying, whereas __set_page_dirty_buffers() is a "top-down" dirtying.
 *
 * Most callers have locked the page, which pins the address_space in memory.
 * But zap_pte_range() does not lock the page, however in that case the
 * mapping is pinned by the vma's ->vm_file reference.
 *
 * We take care to handle the case where the page was truncated from the
 * mapping by re-checking page_mapping() inside tree_lock.
 */
int __set_page_dirty_nobuffers(struct page *page)
{
	if (!TestSetPageDirty(page)) {
		struct address_space *mapping = page_mapping(page);
		struct address_space *mapping2;

		if (!mapping)
			return 1;

		spin_lock_irq(&mapping->tree_lock);
		mapping2 = page_mapping(page);
		if (mapping2) { /* Race with truncate? */
			BUG_ON(mapping2 != mapping);
			WARN_ON_ONCE(!PagePrivate(page) && !PageUptodate(page));
			account_page_dirtied(page, mapping);
			radix_tree_tag_set(&mapping->page_tree,
				page_index(page), PAGECACHE_TAG_DIRTY);
		}
		spin_unlock_irq(&mapping->tree_lock);
		if (mapping->host) {
			/* !PageAnon && !swapper_space */
			__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
		}
		return 1;
	}
	return 0;
}
EXPORT_SYMBOL(__set_page_dirty_nobuffers);

/*
 * When a writepage implementation decides that it doesn't want to write this
 * page for some reason, it should redirty the locked page via
 * redirty_page_for_writepage() and it should then unlock the page and return 0
 */
int redirty_page_for_writepage(struct writeback_control *wbc, struct page *page)
{
	wbc->pages_skipped++;
	return __set_page_dirty_nobuffers(page);
}
Exemplo n.º 26
0
static int ptpfs_file_readpage(struct file *filp, struct page *page)
{
    //printk(KERN_INFO "%s\n",  __FUNCTION__);
    struct inode *inode;
    int ret;
    struct ptp_data_buffer *data=(struct ptp_data_buffer*)filp->private_data;

    inode = page->mapping->host;

    if (!PageLocked(page))
        PAGE_BUG(page);

    ret = -ESTALE;

    /* work out how much to get and from where */
    int offset = page->index << PAGE_CACHE_SHIFT;
    int size   = min((size_t)(inode->i_size - offset),(size_t)PAGE_SIZE);
    char *buffer = kmap(page);
    clear_page(buffer);

    /* read the contents of the file from the server into the page */
    int block = 0;
    while (block < data->num_blocks && offset > data->blocks[block].block_size)
    {
        offset -= data->blocks[block].block_size;
        block++;
    }

    if (block == data->num_blocks)
    {
        kunmap(page);
        ret = -ESTALE;
        goto error;
    }

    int toCopy = min(size,data->blocks[block].block_size-offset);
    memcpy(buffer,&data->blocks[block].block[offset],toCopy);
    size -= toCopy;
    int pos = toCopy;
    block++;
    while (size && block < data->num_blocks)
    {
        toCopy = min(size,data->blocks[block].block_size);
        memcpy(&buffer[pos],data->blocks[block].block,toCopy);
        size -= toCopy;
        pos += toCopy;
        block++;
    }

    if (block == data->num_blocks && size > 0)
    {
        kunmap(page);
        ret = -ESTALE;
        goto error;
    }


    kunmap(page);
    flush_dcache_page(page);
    SetPageUptodate(page);
    unlock_page(page);

    return 0;

    error:
    SetPageError(page);
    unlock_page(page);
    return ret;

} 
Exemplo n.º 27
0
/*
 * "Get" data from cleancache associated with the poolid/inode/index
 * that were specified when the data was put to cleanache and, if
 * successful, use it to fill the specified page with data and return 0.
 * The pageframe is unchanged and returns -1 if the get fails.
 * Page must be locked by caller.
 *
 * The function has two checks before any action is taken - whether
 * a backend is registered and whether the sb->cleancache_poolid
 * is correct.
 */
int __cleancache_get_page(struct page *page)
{
	int ret = -1;
	int pool_id;
	int fake_pool_id;
	struct cleancache_filekey key = { .u.key = { 0 } };

	if (!cleancache_ops) {
		cleancache_failed_gets++;
		goto out;
	}

	VM_BUG_ON_PAGE(!PageLocked(page), page);
	fake_pool_id = page->mapping->host->i_sb->cleancache_poolid;
	if (fake_pool_id < 0)
		goto out;
	pool_id = get_poolid_from_fake(fake_pool_id);

	if (cleancache_get_key(page->mapping->host, &key) < 0)
		goto out;

	if (pool_id >= 0)
		ret = cleancache_ops->get_page(pool_id,
				key, page->index, page);
	if (ret == 0)
		cleancache_succ_gets++;
	else
		cleancache_failed_gets++;
out:
	return ret;
}
EXPORT_SYMBOL(__cleancache_get_page);

/*
 * "Put" data from a page to cleancache and associate it with the
 * (previously-obtained per-filesystem) poolid and the page's,
 * inode and page index.  Page must be locked.  Note that a put_page
 * always "succeeds", though a subsequent get_page may succeed or fail.
 *
 * The function has two checks before any action is taken - whether
 * a backend is registered and whether the sb->cleancache_poolid
 * is correct.
 */
void __cleancache_put_page(struct page *page)
{
	int pool_id;
	int fake_pool_id;
	struct cleancache_filekey key = { .u.key = { 0 } };

	if (!cleancache_ops) {
		cleancache_puts++;
		return;
	}

	VM_BUG_ON_PAGE(!PageLocked(page), page);
	fake_pool_id = page->mapping->host->i_sb->cleancache_poolid;
	if (fake_pool_id < 0)
		return;

	pool_id = get_poolid_from_fake(fake_pool_id);

	if (pool_id >= 0 &&
		cleancache_get_key(page->mapping->host, &key) >= 0) {
		cleancache_ops->put_page(pool_id, key, page->index, page);
		cleancache_puts++;
	}
}
EXPORT_SYMBOL(__cleancache_put_page);

/*
 * Invalidate any data from cleancache associated with the poolid and the
 * page's inode and page index so that a subsequent "get" will fail.
 *
 * The function has two checks before any action is taken - whether
 * a backend is registered and whether the sb->cleancache_poolid
 * is correct.
 */
void __cleancache_invalidate_page(struct address_space *mapping,
					struct page *page)
{
	/* careful... page->mapping is NULL sometimes when this is called */
	int pool_id;
	int fake_pool_id = mapping->host->i_sb->cleancache_poolid;
	struct cleancache_filekey key = { .u.key = { 0 } };

	if (!cleancache_ops)
		return;

	if (fake_pool_id >= 0) {
		pool_id = get_poolid_from_fake(fake_pool_id);
		if (pool_id < 0)
			return;

		VM_BUG_ON_PAGE(!PageLocked(page), page);
		if (cleancache_get_key(mapping->host, &key) >= 0) {
			cleancache_ops->invalidate_page(pool_id,
					key, page->index);
			cleancache_invalidates++;
		}
	}
}
EXPORT_SYMBOL(__cleancache_invalidate_page);

/*
 * Invalidate all data from cleancache associated with the poolid and the
 * mappings's inode so that all subsequent gets to this poolid/inode
 * will fail.
 *
 * The function has two checks before any action is taken - whether
 * a backend is registered and whether the sb->cleancache_poolid
 * is correct.
 */
/*! 2017. 2.25 study -ing */
void __cleancache_invalidate_inode(struct address_space *mapping)
{
	int pool_id;
	int fake_pool_id = mapping->host->i_sb->cleancache_poolid;
	struct cleancache_filekey key = { .u.key = { 0 } };

	if (!cleancache_ops)
		return;

	if (fake_pool_id < 0)
		return;

	pool_id = get_poolid_from_fake(fake_pool_id);

	if (pool_id >= 0 && cleancache_get_key(mapping->host, &key) >= 0)
		cleancache_ops->invalidate_inode(pool_id, key);
}
EXPORT_SYMBOL(__cleancache_invalidate_inode);

/*
 * Called by any cleancache-enabled filesystem at time of unmount;
 * note that pool_id is surrendered and may be returned by a subsequent
 * cleancache_init_fs or cleancache_init_shared_fs.
 */
void __cleancache_invalidate_fs(struct super_block *sb)
{
	int index;
	int fake_pool_id = sb->cleancache_poolid;
	int old_poolid = fake_pool_id;

	mutex_lock(&poolid_mutex);
	if (fake_pool_id >= FAKE_SHARED_FS_POOLID_OFFSET) {
		index = fake_pool_id - FAKE_SHARED_FS_POOLID_OFFSET;
		old_poolid = shared_fs_poolid_map[index];
		shared_fs_poolid_map[index] = FS_UNKNOWN;
		uuids[index] = NULL;
	} else if (fake_pool_id >= FAKE_FS_POOLID_OFFSET) {
		index = fake_pool_id - FAKE_FS_POOLID_OFFSET;
		old_poolid = fs_poolid_map[index];
		fs_poolid_map[index] = FS_UNKNOWN;
	}
	sb->cleancache_poolid = -1;
	if (cleancache_ops)
		cleancache_ops->invalidate_fs(old_poolid);
	mutex_unlock(&poolid_mutex);
}
Exemplo n.º 28
0
			ClearPageSwapCache(page);
			page_cache_release(page);
		}
	}
	return error;
}

/*
 * This must be called only on pages that have
 * been verified to be in the swap cache.
 */
void __delete_from_swap_cache(struct page *page)
{
	swp_entry_t ent = {.val = page_private(page)};

	VM_BUG_ON(!PageLocked(page));
	VM_BUG_ON(!PageSwapCache(page));
	VM_BUG_ON(PageWriteback(page));

	radix_tree_delete(&swapper_space.page_tree, page_private(page));
	set_page_private(page, 0);
	ClearPageSwapCache(page);
	total_swapcache_pages--;
	__dec_zone_page_state(page, NR_FILE_PAGES);
	INC_CACHE_INFO(del_total);
	mem_cgroup_uncharge_swapcache(page, ent);
}

/**
 * add_to_swap - allocate swap space for a page
 * @page: page we want to move to swap
Exemplo n.º 29
0
/**
 * write_one_page - write out a single page and optionally wait on I/O
 * @page: the page to write
 * @wait: if true, wait on writeout
 *
 * The page must be locked by the caller and will be unlocked upon return.
 *
 * write_one_page() returns a negative error code if I/O failed.
 */
int write_one_page(struct page *page, int wait)
{
    struct address_space *mapping = page->mapping;
    int ret = 0;
    struct writeback_control wbc = {
        .sync_mode = WB_SYNC_ALL,
        .nr_to_write = 1,
    };

    BUG_ON(!PageLocked(page));

    if (wait)
        wait_on_page_writeback(page);

    if (clear_page_dirty_for_io(page)) {
        page_cache_get(page);
        ret = mapping->a_ops->writepage(page, &wbc);
        if (ret == 0 && wait) {
            wait_on_page_writeback(page);
            if (PageError(page))
                ret = -EIO;
        }
        page_cache_release(page);
    } else {
        unlock_page(page);
    }
    return ret;
}
EXPORT_SYMBOL(write_one_page);

/*
 * For address_spaces which do not use buffers nor write back.
 */
int __set_page_dirty_no_writeback(struct page *page)
{
    if (!PageDirty(page))
        return !TestSetPageDirty(page);
    return 0;
}

/*
 * Helper function for set_page_dirty family.
 * NOTE: This relies on being atomic wrt interrupts.
 */
void account_page_dirtied(struct page *page, struct address_space *mapping)
{
    if (mapping_cap_account_dirty(mapping)) {
        __inc_zone_page_state(page, NR_FILE_DIRTY);
        __inc_zone_page_state(page, NR_DIRTIED);
        __inc_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE);
        task_dirty_inc(current);
        task_io_account_write(PAGE_CACHE_SIZE);
    }
}
EXPORT_SYMBOL(account_page_dirtied);

/*
 * Helper function for set_page_writeback family.
 * NOTE: Unlike account_page_dirtied this does not rely on being atomic
 * wrt interrupts.
 */
void account_page_writeback(struct page *page)
{
    inc_zone_page_state(page, NR_WRITEBACK);
    inc_zone_page_state(page, NR_WRITTEN);
}
Exemplo n.º 30
0
/*
 * Inspired by write_cache_pages from /mm/page-writeback.c
 */
static int ecryptfs_writepages(struct address_space *mapping,
			       struct writeback_control *wbc)
{
	int ret = 0;
	int done = 0;
	struct pagevec pvec;
	int nr_pages;
	pgoff_t uninitialized_var(writeback_index);
	pgoff_t index;
	pgoff_t end;		/* Inclusive */
	pgoff_t done_index;
	int cycled;
	int range_whole = 0;
	int tag;
	struct page **pgs;
	int pgidx;
	
	/* printk("[g-ecryptfs] Info: call writepages\n"); */

	pgs = kmalloc(sizeof(struct page*)*PAGEVEC_SIZE, GFP_KERNEL);
	if (!pgs) {
		printk("[g-ecryptfs] Error: pgs alloc failed!\n");
		return -EFAULT;
	}

	pagevec_init(&pvec, 0);
	if (wbc->range_cyclic) {
		writeback_index = mapping->writeback_index; /* prev offset */
		index = writeback_index;
		if (index == 0)
			cycled = 1;
		else
			cycled = 0;
		end = -1;
	} else {
		index = wbc->range_start >> PAGE_CACHE_SHIFT;
		end = wbc->range_end >> PAGE_CACHE_SHIFT;
		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
			range_whole = 1;
		cycled = 1; /* ignore range_cyclic tests */
	}
	if (wbc->sync_mode == WB_SYNC_ALL)
		tag = PAGECACHE_TAG_TOWRITE;
	else
		tag = PAGECACHE_TAG_DIRTY;
retry:
	if (wbc->sync_mode == WB_SYNC_ALL)
		tag_pages_for_writeback(mapping, index, end);
	done_index = index;
	while (!done && (index <= end)) {
		int i;
		struct page *page;

		nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
			      min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
		if (nr_pages == 0)
			break;
		pgidx = 0;

		for (i = 0; i < nr_pages; i++) {
			page = pvec.pages[i];

			/*
			 * At this point, the page may be truncated or
			 * invalidated (changing page->mapping to NULL), or
			 * even swizzled back from swapper_space to tmpfs file
			 * mapping. However, page->index will not change
			 * because we have a reference on the page.
			 */
			if (page->index > end) {
				/*
				 * can't be range_cyclic (1st pass) because
				 * end == -1 in that case.
				 */
				done = 1;
				break;
			}

			done_index = page->index + 1;

			lock_page(page);

			/*
			 * Page truncated or invalidated. We can freely skip it
			 * then, even for data integrity operations: the page
			 * has disappeared concurrently, so there could be no
			 * real expectation of this data interity operation
			 * even if there is now a new, dirty page at the same
			 * pagecache address.
			 */
			if (unlikely(page->mapping != mapping)) {
continue_unlock:
				unlock_page(page);
				continue;
			}

			if (!PageDirty(page)) {
				/* someone wrote it for us */
				goto continue_unlock;
			}

			if (PageWriteback(page)) {
				if (wbc->sync_mode != WB_SYNC_NONE)
					wait_on_page_writeback(page);
				else
					goto continue_unlock;
			}

			BUG_ON(PageWriteback(page));
			if (!clear_page_dirty_for_io(page))
				goto continue_unlock;

			pgs[pgidx++] = page;
		}

		/*trace_wbc_writepage(wbc, mapping->backing_dev_info);*/
		ret = ecryptfs_encrypt_pages(pgs, pgidx);
		//printk("[g-ecryptfs] Info: enc %d pages in writepages\n", pgidx);
		mapping_set_error(mapping, ret);

		for (i = 0; i < nr_pages; i++) {
			page = pvec.pages[i];

			if (unlikely(ret)) {
				if (ret == AOP_WRITEPAGE_ACTIVATE) {
					if (PageLocked(page))
						unlock_page(page);
					ret = 0;
				} else {
					/*
					 * done_index is set past this page,
					 * so media errors will not choke
					 * background writeout for the entire
					 * file. This has consequences for
					 * range_cyclic semantics (ie. it may
					 * not be suitable for data integrity
					 * writeout).
					 */
					done = 1;
					break;
				}
			}

			/*
			 * We stop writing back only if we are not doing
			 * integrity sync. In case of integrity sync we have to
			 * keep going until we have written all the pages
			 * we tagged for writeback prior to entering this loop.
			 */
			if (--wbc->nr_to_write <= 0 &&
			    wbc->sync_mode == WB_SYNC_NONE) {
				done = 1;
				break;
			}
		}
		pagevec_release(&pvec);
		cond_resched();
	}
	if (!cycled && !done) {
		/*
		 * range_cyclic:
		 * We hit the last page and there is more work to be done: wrap
		 * back to the start of the file
		 */
		cycled = 1;
		index = 0;
		end = writeback_index - 1;
		goto retry;
	}
	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
		mapping->writeback_index = done_index;

	kfree(pgs);

	return ret;
}