Пример #1
0
/*
 * Decode the result of a readdir call.
 * We're not really decoding anymore, we just leave the buffer untouched
 * and only check that it is syntactically correct.
 * The real decoding happens in nfs_decode_entry below, called directly
 * from nfs_readdir for each entry.
 */
static int
nfs_xdr_readdirres(struct rpc_rqst *req, __be32 *p, void *dummy)
{
	struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
	struct kvec *iov = rcvbuf->head;
	struct page **page;
	size_t hdrlen;
	unsigned int pglen, recvd;
	u32 len;
	int status, nr = 0;
	__be32 *end, *entry, *kaddr;

	if ((status = ntohl(*p++)))
		return nfs_stat_to_errno(status);

	hdrlen = (u8 *) p - (u8 *) iov->iov_base;
	if (iov->iov_len < hdrlen) {
		dprintk("NFS: READDIR reply header overflowed:"
				"length %Zu > %Zu\n", hdrlen, iov->iov_len);
		return -errno_NFSERR_IO;
	} else if (iov->iov_len != hdrlen) {
		dprintk("NFS: READDIR header is short. iovec will be shifted.\n");
		xdr_shift_buf(rcvbuf, iov->iov_len - hdrlen);
	}

	pglen = rcvbuf->page_len;
	recvd = rcvbuf->len - hdrlen;
	if (pglen > recvd)
		pglen = recvd;
	page = rcvbuf->pages;
	kaddr = p = kmap_atomic(*page, KM_USER0);
	end = (__be32 *)((char *)p + pglen);
	entry = p;

	/* Make sure the packet actually has a value_follows and EOF entry */
	if ((entry + 1) > end)
		goto short_pkt;

	for (; *p++; nr++) {
		if (p + 2 > end)
			goto short_pkt;
		p++; /* fileid */
		len = ntohl(*p++);
		p += XDR_QUADLEN(len) + 1;	/* name plus cookie */
		if (len > NFS2_MAXNAMLEN) {
			dprintk("NFS: giant filename in readdir (len 0x%x)!\n",
						len);
			goto err_unmap;
		}
		if (p + 2 > end)
			goto short_pkt;
		entry = p;
	}

	/*
	 * Apparently some server sends responses that are a valid size, but
	 * contain no entries, and have value_follows==0 and EOF==0. For
	 * those, just set the EOF marker.
	 */
	if (!nr && entry[1] == 0) {
		dprintk("NFS: readdir reply truncated!\n");
		entry[1] = 1;
	}
 out:
	kunmap_atomic(kaddr, KM_USER0);
	return nr;
 short_pkt:
	/*
	 * When we get a short packet there are 2 possibilities. We can
	 * return an error, or fix up the response to look like a valid
	 * response and return what we have so far. If there are no
	 * entries and the packet was short, then return -EIO. If there
	 * are valid entries in the response, return them and pretend that
	 * the call was successful, but incomplete. The caller can retry the
	 * readdir starting at the last cookie.
	 */
	entry[0] = entry[1] = 0;
	if (!nr)
		nr = -errno_NFSERR_IO;
	goto out;
err_unmap:
	nr = -errno_NFSERR_IO;
	goto out;
}
Пример #2
0
static int nilfs_cpfile_clear_snapshot(struct inode *cpfile, __u64 cno)
{
	struct buffer_head *header_bh, *next_bh, *prev_bh, *cp_bh;
	struct nilfs_cpfile_header *header;
	struct nilfs_checkpoint *cp;
	struct nilfs_snapshot_list *list;
	__u64 next, prev;
	void *kaddr;
	int ret;

	if (cno == 0)
		return -ENOENT; /* checkpoint number 0 is invalid */
	down_write(&NILFS_MDT(cpfile)->mi_sem);

	ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
	if (ret < 0)
		goto out_sem;
	kaddr = kmap_atomic(cp_bh->b_page);
	cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
	if (nilfs_checkpoint_invalid(cp)) {
		ret = -ENOENT;
		kunmap_atomic(kaddr);
		goto out_cp;
	}
	if (!nilfs_checkpoint_snapshot(cp)) {
		ret = 0;
		kunmap_atomic(kaddr);
		goto out_cp;
	}

	list = &cp->cp_snapshot_list;
	next = le64_to_cpu(list->ssl_next);
	prev = le64_to_cpu(list->ssl_prev);
	kunmap_atomic(kaddr);

	ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
	if (ret < 0)
		goto out_cp;
	if (next != 0) {
		ret = nilfs_cpfile_get_checkpoint_block(cpfile, next, 0,
							&next_bh);
		if (ret < 0)
			goto out_header;
	} else {
		next_bh = header_bh;
		get_bh(next_bh);
	}
	if (prev != 0) {
		ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0,
							&prev_bh);
		if (ret < 0)
			goto out_next;
	} else {
		prev_bh = header_bh;
		get_bh(prev_bh);
	}

	kaddr = kmap_atomic(next_bh->b_page);
	list = nilfs_cpfile_block_get_snapshot_list(
		cpfile, next, next_bh, kaddr);
	list->ssl_prev = cpu_to_le64(prev);
	kunmap_atomic(kaddr);

	kaddr = kmap_atomic(prev_bh->b_page);
	list = nilfs_cpfile_block_get_snapshot_list(
		cpfile, prev, prev_bh, kaddr);
	list->ssl_next = cpu_to_le64(next);
	kunmap_atomic(kaddr);

	kaddr = kmap_atomic(cp_bh->b_page);
	cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
	cp->cp_snapshot_list.ssl_next = cpu_to_le64(0);
	cp->cp_snapshot_list.ssl_prev = cpu_to_le64(0);
	nilfs_checkpoint_clear_snapshot(cp);
	kunmap_atomic(kaddr);

	kaddr = kmap_atomic(header_bh->b_page);
	header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
	le64_add_cpu(&header->ch_nsnapshots, -1);
	kunmap_atomic(kaddr);

	mark_buffer_dirty(next_bh);
	mark_buffer_dirty(prev_bh);
	mark_buffer_dirty(cp_bh);
	mark_buffer_dirty(header_bh);
	nilfs_mdt_mark_dirty(cpfile);

	brelse(prev_bh);

 out_next:
	brelse(next_bh);

 out_header:
	brelse(header_bh);

 out_cp:
	brelse(cp_bh);

 out_sem:
	up_write(&NILFS_MDT(cpfile)->mi_sem);
	return ret;
}
Пример #3
0
/*
 * Attempts to free an entry by adding a page to the swap cache,
 * decompressing the entry data into the page, and issuing a
 * bio write to write the page back to the swap device.
 *
 * This can be thought of as a "resumed writeback" of the page
 * to the swap device.  We are basically resuming the same swap
 * writeback path that was intercepted with the frontswap_store()
 * in the first place.  After the page has been decompressed into
 * the swap cache, the compressed version stored by zswap can be
 * freed.
 */
static int zswap_writeback_entry(struct zpool *pool, unsigned long handle)
{
	struct zswap_header *zhdr;
	swp_entry_t swpentry;
	struct zswap_tree *tree;
	pgoff_t offset;
	struct zswap_entry *entry;
	struct page *page;
	u8 *src, *dst;
	unsigned int dlen;
	int ret;
	struct writeback_control wbc = {
		.sync_mode = WB_SYNC_NONE,
	};

	/* extract swpentry from data */
	zhdr = zpool_map_handle(pool, handle, ZPOOL_MM_RO);
	swpentry = zhdr->swpentry; /* here */
	zpool_unmap_handle(pool, handle);
	tree = zswap_trees[swp_type(swpentry)];
	offset = swp_offset(swpentry);

	/* find and ref zswap entry */
	spin_lock(&tree->lock);
	entry = zswap_entry_find_get(&tree->rbroot, offset);
	if (!entry) {
		/* entry was invalidated */
		spin_unlock(&tree->lock);
		return 0;
	}
	spin_unlock(&tree->lock);
	BUG_ON(offset != entry->offset);

	/* try to allocate swap cache page */
	switch (zswap_get_swap_cache_page(swpentry, &page)) {
	case ZSWAP_SWAPCACHE_FAIL: /* no memory or invalidate happened */
		ret = -ENOMEM;
		goto fail;

	case ZSWAP_SWAPCACHE_EXIST:
		/* page is already in the swap cache, ignore for now */
		page_cache_release(page);
		ret = -EEXIST;
		goto fail;

	case ZSWAP_SWAPCACHE_NEW: /* page is locked */
		/* decompress */
		dlen = PAGE_SIZE;
		src = (u8 *)zpool_map_handle(zswap_pool, entry->handle,
				ZPOOL_MM_RO) + sizeof(struct zswap_header);
		dst = kmap_atomic(page);
		ret = zswap_comp_op(ZSWAP_COMPOP_DECOMPRESS, src,
				entry->length, dst, &dlen);
		kunmap_atomic(dst);
		zpool_unmap_handle(zswap_pool, entry->handle);
		BUG_ON(ret);
		BUG_ON(dlen != PAGE_SIZE);

		/* page is up to date */
		SetPageUptodate(page);
	}

	/* move it to the tail of the inactive list after end_writeback */
	SetPageReclaim(page);

	/* start writeback */
	__swap_writepage(page, &wbc, end_swap_bio_write);
	page_cache_release(page);
	zswap_written_back_pages++;

	spin_lock(&tree->lock);
	/* drop local reference */
	zswap_entry_put(tree, entry);

	/*
	* There are two possible situations for entry here:
	* (1) refcount is 1(normal case),  entry is valid and on the tree
	* (2) refcount is 0, entry is freed and not on the tree
	*     because invalidate happened during writeback
	*  search the tree and free the entry if find entry
	*/
	if (entry == zswap_rb_search(&tree->rbroot, offset))
		zswap_entry_put(tree, entry);
	spin_unlock(&tree->lock);

	goto end;

	/*
	* if we get here due to ZSWAP_SWAPCACHE_EXIST
	* a load may happening concurrently
	* it is safe and okay to not free the entry
	* if we free the entry in the following put
	* it it either okay to return !0
	*/
fail:
	spin_lock(&tree->lock);
	zswap_entry_put(tree, entry);
	spin_unlock(&tree->lock);

end:
	return ret;
}
Пример #4
0
	 */
	for (bytes = 0; bytes < length; offset = 0, bytes += copied) {
		entry = squashfs_cache_get(sb, msblk->block_cache, block, 0);
		if (entry->error) {
			ERROR("Unable to read symlink [%llx:%x]\n",
				squashfs_i(inode)->start,
				squashfs_i(inode)->offset);
			squashfs_cache_put(entry);
			goto error_out;
		}

<<<<<<< HEAD
		pageaddr = kmap_atomic(page);
=======
<<<<<<< HEAD
		pageaddr = kmap_atomic(page);
=======
		pageaddr = kmap_atomic(page, KM_USER0);
>>>>>>> 58a75b6a81be54a8b491263ca1af243e9d8617b9
>>>>>>> ae1773bb70f3d7cf73324ce8fba787e01d8fa9f2
		copied = squashfs_copy_data(pageaddr + bytes, entry, offset,
								length - bytes);
		if (copied == length - bytes)
			memset(pageaddr + length, 0, PAGE_CACHE_SIZE - length);
		else
			block = entry->next_index;
<<<<<<< HEAD
		kunmap_atomic(pageaddr);
=======
<<<<<<< HEAD
		kunmap_atomic(pageaddr);
Пример #5
0
static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,
					  void *buf, unsigned int cisz,
					  size_t nci)
{
	struct buffer_head *bh;
	struct nilfs_cpfile_header *header;
	struct nilfs_checkpoint *cp;
	struct nilfs_cpinfo *ci = buf;
	__u64 curr = *cnop, next;
	unsigned long curr_blkoff, next_blkoff;
	void *kaddr;
	int n = 0, ret;

	down_read(&NILFS_MDT(cpfile)->mi_sem);

	if (curr == 0) {
		ret = nilfs_cpfile_get_header_block(cpfile, &bh);
		if (ret < 0)
			goto out;
		kaddr = kmap_atomic(bh->b_page);
		header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
		curr = le64_to_cpu(header->ch_snapshot_list.ssl_next);
		kunmap_atomic(kaddr);
		brelse(bh);
		if (curr == 0) {
			ret = 0;
			goto out;
		}
	} else if (unlikely(curr == ~(__u64)0)) {
		ret = 0;
		goto out;
	}

	curr_blkoff = nilfs_cpfile_get_blkoff(cpfile, curr);
	ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, 0, &bh);
	if (unlikely(ret < 0)) {
		if (ret == -ENOENT)
			ret = 0; /* No snapshots (started from a hole block) */
		goto out;
	}
	kaddr = kmap_atomic(bh->b_page);
	while (n < nci) {
		cp = nilfs_cpfile_block_get_checkpoint(cpfile, curr, bh, kaddr);
		curr = ~(__u64)0; /* Terminator */
		if (unlikely(nilfs_checkpoint_invalid(cp) ||
			     !nilfs_checkpoint_snapshot(cp)))
			break;
		nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, ci);
		ci = (void *)ci + cisz;
		n++;
		next = le64_to_cpu(cp->cp_snapshot_list.ssl_next);
		if (next == 0)
			break; /* reach end of the snapshot list */

		next_blkoff = nilfs_cpfile_get_blkoff(cpfile, next);
		if (curr_blkoff != next_blkoff) {
			kunmap_atomic(kaddr);
			brelse(bh);
			ret = nilfs_cpfile_get_checkpoint_block(cpfile, next,
								0, &bh);
			if (unlikely(ret < 0)) {
				WARN_ON(ret == -ENOENT);
				goto out;
			}
			kaddr = kmap_atomic(bh->b_page);
		}
		curr = next;
		curr_blkoff = next_blkoff;
	}
	kunmap_atomic(kaddr);
	brelse(bh);
	*cnop = curr;
	ret = n;

 out:
	up_read(&NILFS_MDT(cpfile)->mi_sem);
	return ret;
}
int direct2indirect(struct reiserfs_transaction_handle *th, struct inode *inode,
		    struct treepath *path, struct buffer_head *unbh,
		    loff_t tail_offset)
{
	struct super_block *sb = inode->i_sb;
	struct buffer_head *up_to_date_bh;
	struct item_head *p_le_ih = PATH_PITEM_HEAD(path);
	unsigned long total_tail = 0;
	struct cpu_key end_key;	
	struct item_head ind_ih;	
	int blk_size, retval;	
	unp_t unfm_ptr;		

	BUG_ON(!th->t_trans_id);

	REISERFS_SB(sb)->s_direct2indirect++;

	blk_size = sb->s_blocksize;

	copy_item_head(&ind_ih, p_le_ih);
	set_le_ih_k_offset(&ind_ih, tail_offset);
	set_le_ih_k_type(&ind_ih, TYPE_INDIRECT);

	
	make_cpu_key(&end_key, inode, tail_offset, TYPE_INDIRECT, 4);

	
	if (search_for_position_by_key(sb, &end_key, path) == POSITION_FOUND) {
		reiserfs_error(sb, "PAP-14030",
			       "pasted or inserted byte exists in "
			       "the tree %K. Use fsck to repair.", &end_key);
		pathrelse(path);
		return -EIO;
	}

	p_le_ih = PATH_PITEM_HEAD(path);

	unfm_ptr = cpu_to_le32(unbh->b_blocknr);

	if (is_statdata_le_ih(p_le_ih)) {
		
		set_ih_free_space(&ind_ih, 0);	
		put_ih_item_len(&ind_ih, UNFM_P_SIZE);
		PATH_LAST_POSITION(path)++;
		retval =
		    reiserfs_insert_item(th, path, &end_key, &ind_ih, inode,
					 (char *)&unfm_ptr);
	} else {
		
		retval = reiserfs_paste_into_item(th, path, &end_key, inode,
						    (char *)&unfm_ptr,
						    UNFM_P_SIZE);
	}
	if (retval) {
		return retval;
	}
	
	

	
	make_cpu_key(&end_key, inode, max_reiserfs_offset(inode), TYPE_DIRECT,
		     4);

	while (1) {
		int tail_size;

		if (search_for_position_by_key(sb, &end_key, path) ==
		    POSITION_FOUND)
			reiserfs_panic(sb, "PAP-14050",
				       "direct item (%K) not found", &end_key);
		p_le_ih = PATH_PITEM_HEAD(path);
		RFALSE(!is_direct_le_ih(p_le_ih),
		       "vs-14055: direct item expected(%K), found %h",
		       &end_key, p_le_ih);
		tail_size = (le_ih_k_offset(p_le_ih) & (blk_size - 1))
		    + ih_item_len(p_le_ih) - 1;

		if (!unbh->b_page || buffer_uptodate(unbh)
		    || PageUptodate(unbh->b_page)) {
			up_to_date_bh = NULL;
		} else {
			up_to_date_bh = unbh;
		}
		retval = reiserfs_delete_item(th, path, &end_key, inode,
						up_to_date_bh);

		total_tail += retval;
		if (tail_size == retval)
			
			break;

	}
	if (up_to_date_bh) {
		unsigned pgoff =
		    (tail_offset + total_tail - 1) & (PAGE_CACHE_SIZE - 1);
		char *kaddr = kmap_atomic(up_to_date_bh->b_page);
		memset(kaddr + pgoff, 0, blk_size - total_tail);
		kunmap_atomic(kaddr);
	}

	REISERFS_I(inode)->i_first_direct_byte = U32_MAX;

	return 0;
}
Пример #7
0
int cxgb3i_conn_init_pdu(struct iscsi_task *task, unsigned int offset,
			      unsigned int count)
{
	struct iscsi_conn *conn = task->conn;
	struct iscsi_tcp_task *tcp_task = task->dd_data;
	struct cxgb3i_task_data *tdata = tcp_task->dd_data;
	struct sk_buff *skb = tdata->skb;
	unsigned int datalen = count;
	int i, padlen = iscsi_padding(count);
	struct page *pg;

	cxgb3i_tx_debug("task 0x%p,0x%p, offset %u, count %u, skb 0x%p.\n",
			task, task->sc, offset, count, skb);

	skb_put(skb, task->hdr_len);
	tx_skb_setmode(skb, conn->hdrdgst_en, datalen ? conn->datadgst_en : 0);
	if (!count)
		return 0;

	if (task->sc) {
		struct scsi_data_buffer *sdb = scsi_out(task->sc);
		struct scatterlist *sg = NULL;
		int err;

		tdata->offset = offset;
		tdata->count = count;
		err = sgl_seek_offset(sdb->table.sgl, sdb->table.nents,
					tdata->offset, &tdata->sgoffset, &sg);
		if (err < 0) {
			cxgb3i_log_warn("tpdu, sgl %u, bad offset %u/%u.\n",
					sdb->table.nents, tdata->offset,
					sdb->length);
			return err;
		}
		err = sgl_read_to_frags(sg, tdata->sgoffset, tdata->count,
					tdata->frags, MAX_PDU_FRAGS);
		if (err < 0) {
			cxgb3i_log_warn("tpdu, sgl %u, bad offset %u + %u.\n",
					sdb->table.nents, tdata->offset,
					tdata->count);
			return err;
		}
		tdata->nr_frags = err;

		if (tdata->nr_frags > MAX_SKB_FRAGS ||
		    (padlen && tdata->nr_frags == MAX_SKB_FRAGS)) {
			char *dst = skb->data + task->hdr_len;
			skb_frag_t *frag = tdata->frags;

			/* data fits in the skb's headroom */
			for (i = 0; i < tdata->nr_frags; i++, frag++) {
				char *src = kmap_atomic(frag->page,
							KM_SOFTIRQ0);

				memcpy(dst, src+frag->page_offset, frag->size);
				dst += frag->size;
				kunmap_atomic(src, KM_SOFTIRQ0);
			}
			if (padlen) {
				memset(dst, 0, padlen);
				padlen = 0;
			}
			skb_put(skb, count + padlen);
		} else {
			/* data fit into frag_list */
			for (i = 0; i < tdata->nr_frags; i++)
				get_page(tdata->frags[i].page);

			memcpy(skb_shinfo(skb)->frags, tdata->frags,
				sizeof(skb_frag_t) * tdata->nr_frags);
			skb_shinfo(skb)->nr_frags = tdata->nr_frags;
			skb->len += count;
			skb->data_len += count;
			skb->truesize += count;
		}

	} else {
		pg = virt_to_page(task->data);

		get_page(pg);
		skb_fill_page_desc(skb, 0, pg, offset_in_page(task->data),
					count);
		skb->len += count;
		skb->data_len += count;
		skb->truesize += count;
	}

	if (padlen) {
		i = skb_shinfo(skb)->nr_frags;
		get_page(pad_page);
		skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags, pad_page, 0,
				 padlen);

		skb->data_len += padlen;
		skb->truesize += padlen;
		skb->len += padlen;
	}

	return 0;
}
Пример #8
0
static int mcopy_atomic_pte(struct mm_struct *dst_mm,
			    pmd_t *dst_pmd,
			    struct vm_area_struct *dst_vma,
			    unsigned long dst_addr,
			    unsigned long src_addr,
			    struct page **pagep)
{
	struct mem_cgroup *memcg;
	pte_t _dst_pte, *dst_pte;
	spinlock_t *ptl;
	void *page_kaddr;
	int ret;
	struct page *page;

	if (!*pagep) {
		ret = -ENOMEM;
		page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, dst_vma, dst_addr);
		if (!page)
			goto out;

		page_kaddr = kmap_atomic(page);
		ret = copy_from_user(page_kaddr,
				     (const void __user *) src_addr,
				     PAGE_SIZE);
		kunmap_atomic(page_kaddr);

		/* fallback to copy_from_user outside mmap_sem */
		if (unlikely(ret)) {
			ret = -EFAULT;
			*pagep = page;
			/* don't free the page */
			goto out;
		}
	} else {
		page = *pagep;
		*pagep = NULL;
	}

	/*
	 * The memory barrier inside __SetPageUptodate makes sure that
	 * preceeding stores to the page contents become visible before
	 * the set_pte_at() write.
	 */
	__SetPageUptodate(page);

	ret = -ENOMEM;
	if (mem_cgroup_try_charge(page, dst_mm, GFP_KERNEL, &memcg, false))
		goto out_release;

	_dst_pte = mk_pte(page, dst_vma->vm_page_prot);
	if (dst_vma->vm_flags & VM_WRITE)
		_dst_pte = pte_mkwrite(pte_mkdirty(_dst_pte));

	ret = -EEXIST;
	dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl);
	if (!pte_none(*dst_pte))
		goto out_release_uncharge_unlock;

	inc_mm_counter(dst_mm, MM_ANONPAGES);
	page_add_new_anon_rmap(page, dst_vma, dst_addr, false);
	mem_cgroup_commit_charge(page, memcg, false, false);
	lru_cache_add_active_or_unevictable(page, dst_vma);

	set_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);

	/* No need to invalidate - it was non-present before */
	update_mmu_cache(dst_vma, dst_addr, dst_pte);

	pte_unmap_unlock(dst_pte, ptl);
	ret = 0;
out:
	return ret;
out_release_uncharge_unlock:
	pte_unmap_unlock(dst_pte, ptl);
	mem_cgroup_cancel_charge(page, memcg, false);
out_release:
	page_cache_release(page);
	goto out;
}
Пример #9
0
/*
 * create a vfsmount to be automounted
 */
static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt)
{
	struct afs_super_info *super;
	struct vfsmount *mnt;
	struct afs_vnode *vnode;
	struct page *page;
	char *devname, *options;
	bool rwpath = false;
	int ret;

	_enter("{%pd}", mntpt);

	BUG_ON(!d_inode(mntpt));

	ret = -ENOMEM;
	devname = (char *) get_zeroed_page(GFP_KERNEL);
	if (!devname)
		goto error_no_devname;

	options = (char *) get_zeroed_page(GFP_KERNEL);
	if (!options)
		goto error_no_options;

	vnode = AFS_FS_I(d_inode(mntpt));
	if (test_bit(AFS_VNODE_PSEUDODIR, &vnode->flags)) {
		/* if the directory is a pseudo directory, use the d_name */
		static const char afs_root_cell[] = ":root.cell.";
		unsigned size = mntpt->d_name.len;

		ret = -ENOENT;
		if (size < 2 || size > AFS_MAXCELLNAME)
			goto error_no_page;

		if (mntpt->d_name.name[0] == '.') {
			devname[0] = '#';
			memcpy(devname + 1, mntpt->d_name.name, size - 1);
			memcpy(devname + size, afs_root_cell,
			       sizeof(afs_root_cell));
			rwpath = true;
		} else {
			devname[0] = '%';
			memcpy(devname + 1, mntpt->d_name.name, size);
			memcpy(devname + size + 1, afs_root_cell,
			       sizeof(afs_root_cell));
		}
	} else {
		/* read the contents of the AFS special symlink */
		loff_t size = i_size_read(d_inode(mntpt));
		char *buf;

		ret = -EINVAL;
		if (size > PAGE_SIZE - 1)
			goto error_no_page;

		page = read_mapping_page(d_inode(mntpt)->i_mapping, 0, NULL);
		if (IS_ERR(page)) {
			ret = PTR_ERR(page);
			goto error_no_page;
		}

		ret = -EIO;
		if (PageError(page))
			goto error;

		buf = kmap_atomic(page);
		memcpy(devname, buf, size);
		kunmap_atomic(buf);
		put_page(page);
		page = NULL;
	}

	/* work out what options we want */
	super = AFS_FS_S(mntpt->d_sb);
	memcpy(options, "cell=", 5);
	strcpy(options + 5, super->volume->cell->name);
	if (super->volume->type == AFSVL_RWVOL || rwpath)
		strcat(options, ",rwpath");

	/* try and do the mount */
	_debug("--- attempting mount %s -o %s ---", devname, options);
	mnt = vfs_submount(mntpt, &afs_fs_type, devname, options);
	_debug("--- mount result %p ---", mnt);

	free_page((unsigned long) devname);
	free_page((unsigned long) options);
	_leave(" = %p", mnt);
	return mnt;

error:
	put_page(page);
error_no_page:
	free_page((unsigned long) options);
error_no_options:
	free_page((unsigned long) devname);
error_no_devname:
	_leave(" = %d", ret);
	return ERR_PTR(ret);
}
Пример #10
0
static void memcpy_to_page(struct page *page, size_t offset, char *from, size_t len)
{
	char *to = kmap_atomic(page);
	memcpy(to + offset, from, len);
	kunmap_atomic(to);
}
Пример #11
0
static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes,
			 struct iov_iter *i)
{
	size_t skip, copy, left, wanted;
	const struct iovec *iov;
	char __user *buf;
	void *kaddr, *to;

	if (unlikely(bytes > i->count))
		bytes = i->count;

	if (unlikely(!bytes))
		return 0;

	wanted = bytes;
	iov = i->iov;
	skip = i->iov_offset;
	buf = iov->iov_base + skip;
	copy = min(bytes, iov->iov_len - skip);

	if (!fault_in_pages_readable(buf, copy)) {
		kaddr = kmap_atomic(page);
		to = kaddr + offset;

		/* first chunk, usually the only one */
		left = __copy_from_user_inatomic(to, buf, copy);
		copy -= left;
		skip += copy;
		to += copy;
		bytes -= copy;

		while (unlikely(!left && bytes)) {
			iov++;
			buf = iov->iov_base;
			copy = min(bytes, iov->iov_len);
			left = __copy_from_user_inatomic(to, buf, copy);
			copy -= left;
			skip = copy;
			to += copy;
			bytes -= copy;
		}
		if (likely(!bytes)) {
			kunmap_atomic(kaddr);
			goto done;
		}
		offset = to - kaddr;
		buf += copy;
		kunmap_atomic(kaddr);
		copy = min(bytes, iov->iov_len - skip);
	}
	/* Too bad - revert to non-atomic kmap */
	kaddr = kmap(page);
	to = kaddr + offset;
	left = __copy_from_user(to, buf, copy);
	copy -= left;
	skip += copy;
	to += copy;
	bytes -= copy;
	while (unlikely(!left && bytes)) {
		iov++;
		buf = iov->iov_base;
		copy = min(bytes, iov->iov_len);
		left = __copy_from_user(to, buf, copy);
		copy -= left;
		skip = copy;
		to += copy;
		bytes -= copy;
	}
	kunmap(page);
done:
	if (skip == iov->iov_len) {
		iov++;
		skip = 0;
	}
	i->count -= wanted - bytes;
	i->nr_segs -= iov - i->iov;
	i->iov = iov;
	i->iov_offset = skip;
	return wanted - bytes;
}
Пример #12
0
static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len)
{
	char *from = kmap_atomic(page);
	memcpy(to, from + offset, len);
	kunmap_atomic(from);
}
Пример #13
0
/* path points to first direct item of the file regarless of how many of
   them are there */
int direct2indirect (struct reiserfs_transaction_handle *th, struct inode * inode, 
		     struct path * path, struct buffer_head * unbh,
		     loff_t tail_offset)
{
    struct super_block * sb = inode->i_sb;
    struct buffer_head *up_to_date_bh ;
    struct item_head * p_le_ih = PATH_PITEM_HEAD (path);
    unsigned long total_tail = 0 ;
    struct cpu_key end_key;  /* Key to search for the last byte of the
				converted item. */
    struct item_head ind_ih; /* new indirect item to be inserted or
                                key of unfm pointer to be pasted */
    int	n_blk_size,
      n_retval;	  /* returned value for reiserfs_insert_item and clones */
    unp_t unfm_ptr;  /* Handle on an unformatted node
				       that will be inserted in the
				       tree. */


    REISERFS_SB(sb)->s_direct2indirect ++;

    n_blk_size = sb->s_blocksize;

    /* and key to search for append or insert pointer to the new
       unformatted node. */
    copy_item_head (&ind_ih, p_le_ih);
    set_le_ih_k_offset (&ind_ih, tail_offset);
    set_le_ih_k_type (&ind_ih, TYPE_INDIRECT);

    /* Set the key to search for the place for new unfm pointer */
    make_cpu_key (&end_key, inode, tail_offset, TYPE_INDIRECT, 4);

    // FIXME: we could avoid this 
    if ( search_for_position_by_key (sb, &end_key, path) == POSITION_FOUND ) {
	reiserfs_warning (sb, "PAP-14030: direct2indirect: "
			"pasted or inserted byte exists in the tree %K. "
			"Use fsck to repair.", &end_key);
	pathrelse(path);
	return -EIO;
    }
    
    p_le_ih = PATH_PITEM_HEAD (path);

    unfm_ptr = cpu_to_le32 (unbh->b_blocknr);
    
    if ( is_statdata_le_ih (p_le_ih) )  {
	/* Insert new indirect item. */
	set_ih_free_space (&ind_ih, 0); /* delete at nearest future */
        put_ih_item_len( &ind_ih, UNFM_P_SIZE );
	PATH_LAST_POSITION (path)++;
	n_retval = reiserfs_insert_item (th, path, &end_key, &ind_ih, inode,
					 (char *)&unfm_ptr);
    } else {
	/* Paste into last indirect item of an object. */
	n_retval = reiserfs_paste_into_item(th, path, &end_key, inode,
					    (char *)&unfm_ptr, UNFM_P_SIZE);
    }
    if ( n_retval ) {
	return n_retval;
    }

    // note: from here there are two keys which have matching first
    // three key components. They only differ by the fourth one.


    /* Set the key to search for the direct items of the file */
    make_cpu_key (&end_key, inode, max_reiserfs_offset (inode), TYPE_DIRECT, 4);

    /* Move bytes from the direct items to the new unformatted node
       and delete them. */
    while (1)  {
	int tail_size;

	/* end_key.k_offset is set so, that we will always have found
           last item of the file */
	if ( search_for_position_by_key (sb, &end_key, path) == POSITION_FOUND )
	    reiserfs_panic (sb, "PAP-14050: direct2indirect: "
			    "direct item (%K) not found", &end_key);
	p_le_ih = PATH_PITEM_HEAD (path);
	RFALSE( !is_direct_le_ih (p_le_ih),
	        "vs-14055: direct item expected(%K), found %h",
                &end_key, p_le_ih);
        tail_size = (le_ih_k_offset (p_le_ih) & (n_blk_size - 1))
            + ih_item_len(p_le_ih) - 1;

	/* we only send the unbh pointer if the buffer is not up to date.
	** this avoids overwriting good data from writepage() with old data
	** from the disk or buffer cache
	** Special case: unbh->b_page will be NULL if we are coming through
	** DIRECT_IO handler here.
	*/
	if (!unbh->b_page || buffer_uptodate(unbh) || PageUptodate(unbh->b_page)) {
	    up_to_date_bh = NULL ;
	} else {
	    up_to_date_bh = unbh ;
	}
	n_retval = reiserfs_delete_item (th, path, &end_key, inode, 
	                                 up_to_date_bh) ;

	total_tail += n_retval ;
	if (tail_size == n_retval)
	    // done: file does not have direct items anymore
	    break;

    }
    /* if we've copied bytes from disk into the page, we need to zero
    ** out the unused part of the block (it was not up to date before)
    */
    if (up_to_date_bh) {
        unsigned pgoff = (tail_offset + total_tail - 1) & (PAGE_CACHE_SIZE - 1);
	char *kaddr=kmap_atomic(up_to_date_bh->b_page, KM_USER0);
	memset(kaddr + pgoff, 0, n_blk_size - total_tail) ;
	kunmap_atomic(kaddr, KM_USER0);
    }

    REISERFS_I(inode)->i_first_direct_byte = U32_MAX;

    return 0;
}
Пример #14
0
int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistant_swap_storage)
{
	struct address_space *swap_space;
	struct file *swap_storage;
	struct page *from_page;
	struct page *to_page;
	void *from_virtual;
	void *to_virtual;
	int i;

	BUG_ON(ttm->state != tt_unbound && ttm->state != tt_unpopulated);
	BUG_ON(ttm->caching_state != tt_cached);

	/*
	 * For user buffers, just unpin the pages, as there should be
	 * vma references.
	 */

	if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
		ttm_tt_free_user_pages(ttm);
		ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
		ttm->swap_storage = NULL;
		return 0;
	}

	if (!persistant_swap_storage) {
		swap_storage = shmem_file_setup("ttm swap",
						ttm->num_pages << PAGE_SHIFT,
						0);
		if (unlikely(IS_ERR(swap_storage))) {
			printk(KERN_ERR "Failed allocating swap storage.\n");
			return -ENOMEM;
		}
	} else
		swap_storage = persistant_swap_storage;

	swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;

	for (i = 0; i < ttm->num_pages; ++i) {
		from_page = ttm->pages[i];
		if (unlikely(from_page == NULL))
			continue;
		to_page = read_mapping_page(swap_space, i, NULL);
		if (unlikely(to_page == NULL))
			goto out_err;

		preempt_disable();
		from_virtual = kmap_atomic(from_page, KM_USER0);
		to_virtual = kmap_atomic(to_page, KM_USER1);
		memcpy(to_virtual, from_virtual, PAGE_SIZE);
		kunmap_atomic(to_virtual, KM_USER1);
		kunmap_atomic(from_virtual, KM_USER0);
		preempt_enable();
		set_page_dirty(to_page);
		mark_page_accessed(to_page);
		page_cache_release(to_page);
	}

	ttm_tt_free_alloced_pages(ttm);
	ttm->swap_storage = swap_storage;
	ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
	if (persistant_swap_storage)
		ttm->page_flags |= TTM_PAGE_FLAG_PERSISTANT_SWAP;

	return 0;
out_err:
	if (!persistant_swap_storage)
		fput(swap_storage);

	return -ENOMEM;
}
Пример #15
0
static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
			   int offset)
{
	int ret = 0;
	size_t clen;
	unsigned long handle;
	struct page *page;
	unsigned char *user_mem, *cmem, *src, *uncmem = NULL;
	struct zram_meta *meta = zram->meta;

	page = bvec->bv_page;
	src = meta->compress_buffer;

	if (is_partial_io(bvec)) {
		/*
		 * This is a partial IO. We need to read the full page
		 * before to write the changes.
		 */
		uncmem = kmalloc(PAGE_SIZE, GFP_NOIO);
		if (!uncmem) {
			ret = -ENOMEM;
			goto out;
		}
		ret = zram_decompress_page(zram, uncmem, index);
		if (ret)
			goto out;
	}

	/*
	 * System overwrites unused sectors. Free memory associated
	 * with this sector now.
	 */
	if (meta->table[index].handle ||
	    zram_test_flag(meta, index, ZRAM_ZERO))
		zram_free_page(zram, index);

	user_mem = kmap_atomic(page);

	if (is_partial_io(bvec)) {
		memcpy(uncmem + offset, user_mem + bvec->bv_offset,
		       bvec->bv_len);
		kunmap_atomic(user_mem);
		user_mem = NULL;
	} else {
		uncmem = user_mem;
	}

	if (page_zero_filled(uncmem)) {
		kunmap_atomic(user_mem);
		if (is_partial_io(bvec))
			kfree(uncmem);
		zram->stats.pages_zero++;
		zram_set_flag(meta, index, ZRAM_ZERO);
		ret = 0;
		goto out;
	}

	ret = lzo1x_1_compress(uncmem, PAGE_SIZE, src, &clen,
			       meta->compress_workmem);

	if (!is_partial_io(bvec)) {
		kunmap_atomic(user_mem);
		user_mem = NULL;
		uncmem = NULL;
	}

	if (unlikely(ret != LZO_E_OK)) {
		pr_err("Compression failed! err=%d\n", ret);
		goto out;
	}

	if (unlikely(clen > max_zpage_size)) {
		zram->stats.bad_compress++;
		clen = PAGE_SIZE;
		src = NULL;
		if (is_partial_io(bvec))
			src = uncmem;
	}

	handle = zs_malloc(meta->mem_pool, clen);
	if (!handle) {
		pr_info("Error allocating memory for compressed "
			"page: %u, size=%zu\n", index, clen);
		ret = -ENOMEM;
		goto out;
	}
	cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_WO);

	if ((clen == PAGE_SIZE) && !is_partial_io(bvec))
		src = kmap_atomic(page);
	memcpy(cmem, src, clen);
	if ((clen == PAGE_SIZE) && !is_partial_io(bvec))
		kunmap_atomic(src);

	zs_unmap_object(meta->mem_pool, handle);

	meta->table[index].handle = handle;
	meta->table[index].size = clen;

	/* Update stats */
	zram_stat64_add(zram, &zram->stats.compr_size, clen);
	zram->stats.pages_stored++;
	if (clen <= PAGE_SIZE / 2)
		zram->stats.good_compress++;

out:
	if (is_partial_io(bvec))
		kfree(uncmem);

	if (ret)
		zram_stat64_inc(zram, &zram->stats.failed_writes);
	return ret;
}
Пример #16
0
static int uloop_xfer(struct loop_device *lo, int cmd,
		      struct page *raw_page, unsigned int raw_off,
		      struct page *loop_page, unsigned int loop_off,
		      int size, sector_t real_block)
{
	int err, set, bit, sz;
	struct ulo_dev *dev;
	char *raw_buf, *loop_buf;
	loff_t pos, loff;
	unsigned long pindex;
	struct mutex *mtx;
	const unsigned long bmp_page_bytes = PAGE_SIZE * BITS_PER_BYTE;

#if 0
	UloDbg("raw_off %u, loop_off %u, sz %d, real_block %lu\n",
	       raw_off, loop_off, size, real_block);
#endif

#if 0
	err = -EACCES;
	if (unlikely(cmd != READ))
		goto out;
#endif
	err = -ESRCH;
	dev = lo->private_data;
	if (unlikely(!dev || !dev->bmp))
		goto out;

	pos = real_block;
	//pos *= KERNEL_SECTOR_SIZE;
	pos *= 512;
	//pos += loop_off;
#if 0
	UloDbg("pos %Lu, raw_off %u, loop_off %u, sz %d, real_block %lu\n",
	       pos, raw_off, loop_off, size, real_block);
#endif

	// todo: optimize (or make intelligent) this loop
	err = 0;
	sz = size;
	mtx = &dev->bmpmtx;
	while (sz > 0) {
		/* test bitmap */
		set = 1;
		loff = pos / PAGE_SIZE;
		pindex = loff / bmp_page_bytes;
		bit = loff % bmp_page_bytes;
		//Dbg("pindex %lu, bit %d\n", pindex, bit);
		mutex_lock(mtx);
		err = ulo_bmp_pindex(dev, pindex);
		if (!err)
			set = test_bit(bit, dev->bmpbuf);
		mutex_unlock(mtx);
		if (unlikely(err))
			goto out;

		/* xfer by userspace */
		if (!set) {
			err = ulo_xfer_begin(dev, pos, PAGE_SIZE);
			if (!err)
				err = ulo_xfer_end(dev, pos, PAGE_SIZE, pindex,
						   bit);
			if (unlikely(err))
				goto out;
		}

		sz -= PAGE_SIZE;
		pos += PAGE_SIZE;
	}

	/* satisfy the request */
	if (!err) {
		raw_buf = kmap_atomic(raw_page, KM_USER0) + raw_off;
		loop_buf = kmap_atomic(loop_page, KM_USER1) + loop_off;
		memcpy(loop_buf, raw_buf, size);
		kunmap_atomic(raw_buf, KM_USER0);
		kunmap_atomic(loop_buf, KM_USER1);
		cond_resched();
	}
 out:
	UloDbgErr(err);
	return err;
}
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;

	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_INCOMPAT_FEATURE(inode->i_sb,
				      EXT4_FEATURE_INCOMPAT_EXTENTS)) {
		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;
}
Пример #18
0
static inline char *wbsd_map_sg(struct wbsd_host *host)
{
	return kmap_atomic(sg_page(host->cur_sg)) + host->cur_sg->offset;
}
Пример #19
0
static inline dma_addr_t map_single_or_page(struct device *dev, void *ptr,
		struct page *page, unsigned long offset,  size_t size,
		enum dma_data_direction dir)
{
	struct dmabounce_device_info *device_info = dev->archdata.dmabounce;
	dma_addr_t dma_addr;
	int needs_bounce = 0;

	if (device_info)
		DO_STATS ( device_info->map_op_count++ );

	if (page)
		dma_addr = page_to_dma(dev, page) + offset;
	else
		dma_addr = virt_to_dma(dev, ptr);

	if (dev->dma_mask) {
		unsigned long mask = *dev->dma_mask;
		unsigned long limit;

		limit = (mask - 1) | mask;
		limit = (limit + 1) & ~limit;
		if (limit && size > limit) {
			dev_err(dev, "DMA mapping too big (requested %#x "
				"mask %#Lx)\n", size, *dev->dma_mask);
			return ~0;
		}

		/*
		 * Figure out if we need to bounce from the DMA mask.
		 */
		needs_bounce = (dma_addr & ~mask) ||
			(limit && (dma_addr + size > limit));
	}

	if (device_info && (needs_bounce || dma_needs_bounce(dev, dma_addr, size))) {
		struct safe_buffer *buf;

		buf = alloc_safe_buffer(device_info, ptr, page, offset, size, dir);
		if (buf == 0) {
			dev_err(dev, "%s: unable to map unsafe buffer %p!\n",
			       __func__, ptr);
			return 0;
		}

                if (buf->page)
			dev_dbg(dev, "%s: unsafe buffer %p (dma=%#x) mapped "
				"to %p (dma=%#x)\n", __func__,
				page_address(buf->page),
				page_to_dma(dev, buf->page),
				buf->safe, buf->safe_dma_addr);
		else
			dev_dbg(dev, "%s: unsafe buffer %p (dma=%#x) mapped "
				"to %p (dma=%#x)\n", __func__,
				buf->ptr, virt_to_dma(dev, buf->ptr),
				buf->safe, buf->safe_dma_addr);

		if ((dir == DMA_TO_DEVICE) ||
		    (dir == DMA_BIDIRECTIONAL)) {
			if (page)
				ptr = kmap_atomic(page, KM_BOUNCE_READ) + offset;
			dev_dbg(dev, "%s: copy unsafe %p to safe %p, size %d\n",
				__func__, ptr, buf->safe, size);
			memcpy(buf->safe, ptr, size);
			wmb();
			if (page)
				kunmap_atomic(ptr - offset, KM_BOUNCE_READ);
		}
		dma_addr = buf->safe_dma_addr;
	} else {
		/*
		 * We don't need to sync the DMA buffer since
		 * it was allocated via the coherent allocators.
		 */
		if (page)
			__dma_page_cpu_to_dev(page, offset, size, dir);
		else
			__dma_single_cpu_to_dev(ptr, size, dir);
	}

	return dma_addr;
}
Пример #20
0
static int copy_user_bh(struct page *to, struct inode *inode,
		struct buffer_head *bh, unsigned long vaddr)
{
	struct blk_dax_ctl dax = {
		.sector = to_sector(bh, inode),
		.size = bh->b_size,
	};
	struct block_device *bdev = bh->b_bdev;
	void *vto;

	if (dax_map_atomic(bdev, &dax) < 0)
		return PTR_ERR(dax.addr);
	vto = kmap_atomic(to);
	copy_user_page(vto, (void __force *)dax.addr, vaddr, to);
	kunmap_atomic(vto);
	dax_unmap_atomic(bdev, &dax);
	return 0;
}

#define NO_SECTOR -1
#define DAX_PMD_INDEX(page_index) (page_index & (PMD_MASK >> PAGE_CACHE_SHIFT))

static int dax_radix_entry(struct address_space *mapping, pgoff_t index,
		sector_t sector, bool pmd_entry, bool dirty)
{
	struct radix_tree_root *page_tree = &mapping->page_tree;
	pgoff_t pmd_index = DAX_PMD_INDEX(index);
	int type, error = 0;
	void *entry;

	WARN_ON_ONCE(pmd_entry && !dirty);
	if (dirty)
		__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);

	spin_lock_irq(&mapping->tree_lock);

	entry = radix_tree_lookup(page_tree, pmd_index);
	if (entry && RADIX_DAX_TYPE(entry) == RADIX_DAX_PMD) {
		index = pmd_index;
		goto dirty;
	}

	entry = radix_tree_lookup(page_tree, index);
	if (entry) {
		type = RADIX_DAX_TYPE(entry);
		if (WARN_ON_ONCE(type != RADIX_DAX_PTE &&
					type != RADIX_DAX_PMD)) {
			error = -EIO;
			goto unlock;
		}

		if (!pmd_entry || type == RADIX_DAX_PMD)
			goto dirty;

		/*
		 * We only insert dirty PMD entries into the radix tree.  This
		 * means we don't need to worry about removing a dirty PTE
		 * entry and inserting a clean PMD entry, thus reducing the
		 * range we would flush with a follow-up fsync/msync call.
		 */
		radix_tree_delete(&mapping->page_tree, index);
		mapping->nrexceptional--;
	}

	if (sector == NO_SECTOR) {
		/*
		 * This can happen during correct operation if our pfn_mkwrite
		 * fault raced against a hole punch operation.  If this
		 * happens the pte that was hole punched will have been
		 * unmapped and the radix tree entry will have been removed by
		 * the time we are called, but the call will still happen.  We
		 * will return all the way up to wp_pfn_shared(), where the
		 * pte_same() check will fail, eventually causing page fault
		 * to be retried by the CPU.
		 */
		goto unlock;
	}

	error = radix_tree_insert(page_tree, index,
			RADIX_DAX_ENTRY(sector, pmd_entry));
	if (error)
		goto unlock;

	mapping->nrexceptional++;
 dirty:
	if (dirty)
		radix_tree_tag_set(page_tree, index, PAGECACHE_TAG_DIRTY);
 unlock:
	spin_unlock_irq(&mapping->tree_lock);
	return error;
}

static int dax_writeback_one(struct block_device *bdev,
		struct address_space *mapping, pgoff_t index, void *entry)
{
	struct radix_tree_root *page_tree = &mapping->page_tree;
	int type = RADIX_DAX_TYPE(entry);
	struct radix_tree_node *node;
	struct blk_dax_ctl dax;
	void **slot;
	int ret = 0;

	spin_lock_irq(&mapping->tree_lock);
	/*
	 * Regular page slots are stabilized by the page lock even
	 * without the tree itself locked.  These unlocked entries
	 * need verification under the tree lock.
	 */
	if (!__radix_tree_lookup(page_tree, index, &node, &slot))
		goto unlock;
	if (*slot != entry)
		goto unlock;

	/* another fsync thread may have already written back this entry */
	if (!radix_tree_tag_get(page_tree, index, PAGECACHE_TAG_TOWRITE))
		goto unlock;

	if (WARN_ON_ONCE(type != RADIX_DAX_PTE && type != RADIX_DAX_PMD)) {
		ret = -EIO;
		goto unlock;
	}

	dax.sector = RADIX_DAX_SECTOR(entry);
	dax.size = (type == RADIX_DAX_PMD ? PMD_SIZE : PAGE_SIZE);
	spin_unlock_irq(&mapping->tree_lock);

	/*
	 * We cannot hold tree_lock while calling dax_map_atomic() because it
	 * eventually calls cond_resched().
	 */
	ret = dax_map_atomic(bdev, &dax);
	if (ret < 0)
		return ret;

	if (WARN_ON_ONCE(ret < dax.size)) {
		ret = -EIO;
		goto unmap;
	}

	wb_cache_pmem(dax.addr, dax.size);

	spin_lock_irq(&mapping->tree_lock);
	radix_tree_tag_clear(page_tree, index, PAGECACHE_TAG_TOWRITE);
	spin_unlock_irq(&mapping->tree_lock);
 unmap:
	dax_unmap_atomic(bdev, &dax);
	return ret;

 unlock:
	spin_unlock_irq(&mapping->tree_lock);
	return ret;
}

/*
 * Flush the mapping to the persistent domain within the byte range of [start,
 * end]. This is required by data integrity operations to ensure file data is
 * on persistent storage prior to completion of the operation.
 */
int dax_writeback_mapping_range(struct address_space *mapping,
		struct block_device *bdev, struct writeback_control *wbc)
{
	struct inode *inode = mapping->host;
	pgoff_t start_index, end_index, pmd_index;
	pgoff_t indices[PAGEVEC_SIZE];
	struct pagevec pvec;
	bool done = false;
	int i, ret = 0;
	void *entry;

	if (WARN_ON_ONCE(inode->i_blkbits != PAGE_SHIFT))
		return -EIO;

	if (!mapping->nrexceptional || wbc->sync_mode != WB_SYNC_ALL)
		return 0;

	start_index = wbc->range_start >> PAGE_CACHE_SHIFT;
	end_index = wbc->range_end >> PAGE_CACHE_SHIFT;
	pmd_index = DAX_PMD_INDEX(start_index);

	rcu_read_lock();
	entry = radix_tree_lookup(&mapping->page_tree, pmd_index);
	rcu_read_unlock();

	/* see if the start of our range is covered by a PMD entry */
	if (entry && RADIX_DAX_TYPE(entry) == RADIX_DAX_PMD)
		start_index = pmd_index;

	tag_pages_for_writeback(mapping, start_index, end_index);

	pagevec_init(&pvec, 0);
	while (!done) {
		pvec.nr = find_get_entries_tag(mapping, start_index,
				PAGECACHE_TAG_TOWRITE, PAGEVEC_SIZE,
				pvec.pages, indices);

		if (pvec.nr == 0)
			break;

		for (i = 0; i < pvec.nr; i++) {
			if (indices[i] > end_index) {
				done = true;
				break;
			}

			ret = dax_writeback_one(bdev, mapping, indices[i],
					pvec.pages[i]);
			if (ret < 0)
				return ret;
		}
	}
	wmb_pmem();
	return 0;
}
EXPORT_SYMBOL_GPL(dax_writeback_mapping_range);

static int dax_insert_mapping(struct inode *inode, struct buffer_head *bh,
			struct vm_area_struct *vma, struct vm_fault *vmf)
{
	unsigned long vaddr = (unsigned long)vmf->virtual_address;
	struct address_space *mapping = inode->i_mapping;
	struct block_device *bdev = bh->b_bdev;
	struct blk_dax_ctl dax = {
		.sector = to_sector(bh, inode),
		.size = bh->b_size,
	};
	pgoff_t size;
	int error;

	i_mmap_lock_read(mapping);

	/*
	 * Check truncate didn't happen while we were allocating a block.
	 * If it did, this block may or may not be still allocated to the
	 * file.  We can't tell the filesystem to free it because we can't
	 * take i_mutex here.  In the worst case, the file still has blocks
	 * allocated past the end of the file.
	 */
	size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
	if (unlikely(vmf->pgoff >= size)) {
		error = -EIO;
		goto out;
	}

	if (dax_map_atomic(bdev, &dax) < 0) {
		error = PTR_ERR(dax.addr);
		goto out;
	}

	if (buffer_unwritten(bh) || buffer_new(bh)) {
		clear_pmem(dax.addr, PAGE_SIZE);
		wmb_pmem();
	}
	dax_unmap_atomic(bdev, &dax);

	error = dax_radix_entry(mapping, vmf->pgoff, dax.sector, false,
			vmf->flags & FAULT_FLAG_WRITE);
	if (error)
		goto out;

	error = vm_insert_mixed(vma, vaddr, dax.pfn);

 out:
	i_mmap_unlock_read(mapping);

	return error;
}

/**
 * __dax_fault - handle a page fault on a DAX file
 * @vma: The virtual memory area where the fault occurred
 * @vmf: The description of the fault
 * @get_block: The filesystem method used to translate file offsets to blocks
 * @complete_unwritten: The filesystem method used to convert unwritten blocks
 *	to written so the data written to them is exposed. This is required for
 *	required by write faults for filesystems that will return unwritten
 *	extent mappings from @get_block, but it is optional for reads as
 *	dax_insert_mapping() will always zero unwritten blocks. If the fs does
 *	not support unwritten extents, the it should pass NULL.
 *
 * When a page fault occurs, filesystems may call this helper in their
 * fault handler for DAX files. __dax_fault() assumes the caller has done all
 * the necessary locking for the page fault to proceed successfully.
 */
int __dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
			get_block_t get_block, dax_iodone_t complete_unwritten)
{
	struct file *file = vma->vm_file;
	struct address_space *mapping = file->f_mapping;
	struct inode *inode = mapping->host;
	struct page *page;
	struct buffer_head bh;
	unsigned long vaddr = (unsigned long)vmf->virtual_address;
	unsigned blkbits = inode->i_blkbits;
	sector_t block;
	pgoff_t size;
	int error;
	int major = 0;

	size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
	if (vmf->pgoff >= size)
		return VM_FAULT_SIGBUS;

	memset(&bh, 0, sizeof(bh));
	block = (sector_t)vmf->pgoff << (PAGE_SHIFT - blkbits);
	bh.b_bdev = inode->i_sb->s_bdev;
	bh.b_size = PAGE_SIZE;

 repeat:
	page = find_get_page(mapping, vmf->pgoff);
	if (page) {
		if (!lock_page_or_retry(page, vma->vm_mm, vmf->flags)) {
			page_cache_release(page);
			return VM_FAULT_RETRY;
		}
		if (unlikely(page->mapping != mapping)) {
			unlock_page(page);
			page_cache_release(page);
			goto repeat;
		}
		size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
		if (unlikely(vmf->pgoff >= size)) {
			/*
			 * We have a struct page covering a hole in the file
			 * from a read fault and we've raced with a truncate
			 */
			error = -EIO;
			goto unlock_page;
		}
	}

	error = get_block(inode, block, &bh, 0);
	if (!error && (bh.b_size < PAGE_SIZE))
		error = -EIO;		/* fs corruption? */
	if (error)
		goto unlock_page;

	if (!buffer_mapped(&bh) && !buffer_unwritten(&bh) && !vmf->cow_page) {
		if (vmf->flags & FAULT_FLAG_WRITE) {
			error = get_block(inode, block, &bh, 1);
			count_vm_event(PGMAJFAULT);
			mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT);
			major = VM_FAULT_MAJOR;
			if (!error && (bh.b_size < PAGE_SIZE))
				error = -EIO;
			if (error)
				goto unlock_page;
		} else {
			return dax_load_hole(mapping, page, vmf);
		}
	}

	if (vmf->cow_page) {
		struct page *new_page = vmf->cow_page;
		if (buffer_written(&bh))
			error = copy_user_bh(new_page, inode, &bh, vaddr);
		else
			clear_user_highpage(new_page, vaddr);
		if (error)
			goto unlock_page;
		vmf->page = page;
		if (!page) {
			i_mmap_lock_read(mapping);
			/* Check we didn't race with truncate */
			size = (i_size_read(inode) + PAGE_SIZE - 1) >>
								PAGE_SHIFT;
			if (vmf->pgoff >= size) {
				i_mmap_unlock_read(mapping);
				error = -EIO;
				goto out;
			}
		}
		return VM_FAULT_LOCKED;
	}

	/* Check we didn't race with a read fault installing a new page */
	if (!page && major)
		page = find_lock_page(mapping, vmf->pgoff);

	if (page) {
		unmap_mapping_range(mapping, vmf->pgoff << PAGE_SHIFT,
							PAGE_CACHE_SIZE, 0);
		delete_from_page_cache(page);
		unlock_page(page);
		page_cache_release(page);
		page = NULL;
	}

	/*
	 * If we successfully insert the new mapping over an unwritten extent,
	 * we need to ensure we convert the unwritten extent. If there is an
	 * error inserting the mapping, the filesystem needs to leave it as
	 * unwritten to prevent exposure of the stale underlying data to
	 * userspace, but we still need to call the completion function so
	 * the private resources on the mapping buffer can be released. We
	 * indicate what the callback should do via the uptodate variable, same
	 * as for normal BH based IO completions.
	 */
	error = dax_insert_mapping(inode, &bh, vma, vmf);
	if (buffer_unwritten(&bh)) {
		if (complete_unwritten)
			complete_unwritten(&bh, !error);
		else
			WARN_ON_ONCE(!(vmf->flags & FAULT_FLAG_WRITE));
	}

 out:
	if (error == -ENOMEM)
		return VM_FAULT_OOM | major;
	/* -EBUSY is fine, somebody else faulted on the same PTE */
	if ((error < 0) && (error != -EBUSY))
		return VM_FAULT_SIGBUS | major;
	return VM_FAULT_NOPAGE | major;

 unlock_page:
	if (page) {
		unlock_page(page);
		page_cache_release(page);
	}
	goto out;
}
Пример #21
0
static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
				   struct buffer_head *bh_result, int create)
{
	int err = -EIO;
	int status;
	struct ocfs2_dinode *fe = NULL;
	struct buffer_head *bh = NULL;
	struct buffer_head *buffer_cache_bh = NULL;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	void *kaddr;

	trace_ocfs2_symlink_get_block(
			(unsigned long long)OCFS2_I(inode)->ip_blkno,
			(unsigned long long)iblock, bh_result, create);

	BUG_ON(ocfs2_inode_is_fast_symlink(inode));

	if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
		mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
		     (unsigned long long)iblock);
		goto bail;
	}

	status = ocfs2_read_inode_block(inode, &bh);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}
	fe = (struct ocfs2_dinode *) bh->b_data;

	if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
						    le32_to_cpu(fe->i_clusters))) {
		mlog(ML_ERROR, "block offset is outside the allocated size: "
		     "%llu\n", (unsigned long long)iblock);
		goto bail;
	}

	if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
		u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
			    iblock;
		buffer_cache_bh = sb_getblk(osb->sb, blkno);
		if (!buffer_cache_bh) {
			mlog(ML_ERROR, "couldn't getblock for symlink!\n");
			goto bail;
		}

		if (buffer_jbd(buffer_cache_bh)
		    && ocfs2_inode_is_new(inode)) {
			kaddr = kmap_atomic(bh_result->b_page);
			if (!kaddr) {
				mlog(ML_ERROR, "couldn't kmap!\n");
				goto bail;
			}
			memcpy(kaddr + (bh_result->b_size * iblock),
			       buffer_cache_bh->b_data,
			       bh_result->b_size);
			kunmap_atomic(kaddr);
			set_buffer_uptodate(bh_result);
		}
		brelse(buffer_cache_bh);
	}

	map_bh(bh_result, inode->i_sb,
	       le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);

	err = 0;

bail:
	brelse(bh);

	return err;
}
Пример #22
0
static int
ecryptfs_copy_up_encrypted_with_header(struct page *page,
				       struct ecryptfs_crypt_stat *crypt_stat)
{
	loff_t extent_num_in_page = 0;
	loff_t num_extents_per_page = (PAGE_CACHE_SIZE
				       / crypt_stat->extent_size);
	int rc = 0;

	while (extent_num_in_page < num_extents_per_page) {
		loff_t view_extent_num = ((((loff_t)page->index)
					   * num_extents_per_page)
					  + extent_num_in_page);
		size_t num_header_extents_at_front =
			(crypt_stat->metadata_size / crypt_stat->extent_size);

		if (view_extent_num < num_header_extents_at_front) {
			
			char *page_virt;

			page_virt = kmap_atomic(page);
			memset(page_virt, 0, PAGE_CACHE_SIZE);
			
			if (view_extent_num == 0) {
				size_t written;

				rc = ecryptfs_read_xattr_region(
					page_virt, page->mapping->host);
				strip_xattr_flag(page_virt + 16, crypt_stat);
				ecryptfs_write_header_metadata(page_virt + 20,
							       crypt_stat,
							       &written);
			}
			kunmap_atomic(page_virt);
			flush_dcache_page(page);
			if (rc) {
				printk(KERN_ERR "%s: Error reading xattr "
				       "region; rc = [%d]\n", __func__, rc);
				goto out;
			}
		} else {
			
			loff_t lower_offset =
				((view_extent_num * crypt_stat->extent_size)
				 - crypt_stat->metadata_size);

			rc = ecryptfs_read_lower_page_segment(
				page, (lower_offset >> PAGE_CACHE_SHIFT),
				(lower_offset & ~PAGE_CACHE_MASK),
				crypt_stat->extent_size, page->mapping->host);
			if (rc) {
				printk(KERN_ERR "%s: Error attempting to read "
				       "extent at offset [%lld] in the lower "
				       "file; rc = [%d]\n", __func__,
				       lower_offset, rc);
				goto out;
			}
		}
		extent_num_in_page++;
	}
out:
	return rc;
}
Пример #23
0
/**
 * nilfs_cpfile_delete_checkpoints - delete checkpoints
 * @cpfile: inode of checkpoint file
 * @start: start checkpoint number
 * @end: end checkpoint numer
 *
 * Description: nilfs_cpfile_delete_checkpoints() deletes the checkpoints in
 * the period from @start to @end, excluding @end itself. The checkpoints
 * which have been already deleted are ignored.
 *
 * Return Value: On success, 0 is returned. On error, one of the following
 * negative error codes is returned.
 *
 * %-EIO - I/O error.
 *
 * %-ENOMEM - Insufficient amount of memory available.
 *
 * %-EINVAL - invalid checkpoints.
 */
int nilfs_cpfile_delete_checkpoints(struct inode *cpfile,
				    __u64 start,
				    __u64 end)
{
	struct buffer_head *header_bh, *cp_bh;
	struct nilfs_cpfile_header *header;
	struct nilfs_checkpoint *cp;
	size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
	__u64 cno;
	void *kaddr;
	unsigned long tnicps;
	int ret, ncps, nicps, nss, count, i;

	if (unlikely(start == 0 || start > end)) {
		printk(KERN_ERR "%s: invalid range of checkpoint numbers: "
		       "[%llu, %llu)\n", __func__,
		       (unsigned long long)start, (unsigned long long)end);
		return -EINVAL;
	}

	down_write(&NILFS_MDT(cpfile)->mi_sem);

	ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
	if (ret < 0)
		goto out_sem;
	tnicps = 0;
	nss = 0;

	for (cno = start; cno < end; cno += ncps) {
		ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, end);
		ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
		if (ret < 0) {
			if (ret != -ENOENT)
				break;
			/* skip hole */
			ret = 0;
			continue;
		}

		kaddr = kmap_atomic(cp_bh->b_page);
		cp = nilfs_cpfile_block_get_checkpoint(
			cpfile, cno, cp_bh, kaddr);
		nicps = 0;
		for (i = 0; i < ncps; i++, cp = (void *)cp + cpsz) {
			if (nilfs_checkpoint_snapshot(cp)) {
				nss++;
			} else if (!nilfs_checkpoint_invalid(cp)) {
				nilfs_checkpoint_set_invalid(cp);
				nicps++;
			}
		}
		if (nicps > 0) {
			tnicps += nicps;
			mark_buffer_dirty(cp_bh);
			nilfs_mdt_mark_dirty(cpfile);
			if (!nilfs_cpfile_is_in_first(cpfile, cno)) {
				count =
				  nilfs_cpfile_block_sub_valid_checkpoints(
						cpfile, cp_bh, kaddr, nicps);
				if (count == 0) {
					/* make hole */
					kunmap_atomic(kaddr);
					brelse(cp_bh);
					ret =
					  nilfs_cpfile_delete_checkpoint_block(
								   cpfile, cno);
					if (ret == 0)
						continue;
					printk(KERN_ERR
					       "%s: cannot delete block\n",
					       __func__);
					break;
				}
			}
		}

		kunmap_atomic(kaddr);
		brelse(cp_bh);
	}

	if (tnicps > 0) {
		kaddr = kmap_atomic(header_bh->b_page);
		header = nilfs_cpfile_block_get_header(cpfile, header_bh,
						       kaddr);
		le64_add_cpu(&header->ch_ncheckpoints, -(u64)tnicps);
		mark_buffer_dirty(header_bh);
		nilfs_mdt_mark_dirty(cpfile);
		kunmap_atomic(kaddr);
	}

	brelse(header_bh);
	if (nss > 0)
		ret = -EBUSY;

 out_sem:
	up_write(&NILFS_MDT(cpfile)->mi_sem);
	return ret;
}
Пример #24
0
int journal_write_metadata_buffer(transaction_t *transaction,
				  struct journal_head  *jh_in,
				  struct journal_head **jh_out,
				  unsigned int blocknr)
{
	int need_copy_out = 0;
	int done_copy_out = 0;
	int do_escape = 0;
	char *mapped_data;
	struct buffer_head *new_bh;
	struct journal_head *new_jh;
	struct page *new_page;
	unsigned int new_offset;
	struct buffer_head *bh_in = jh2bh(jh_in);
	journal_t *journal = transaction->t_journal;

	/*
	 * The buffer really shouldn't be locked: only the current committing
	 * transaction is allowed to write it, so nobody else is allowed
	 * to do any IO.
	 *
	 * akpm: except if we're journalling data, and write() output is
	 * also part of a shared mapping, and another thread has
	 * decided to launch a writepage() against this buffer.
	 */
	J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in));

	new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL);
	/* keep subsequent assertions sane */
	new_bh->b_state = 0;
	init_buffer(new_bh, NULL, NULL);
	atomic_set(&new_bh->b_count, 1);
	new_jh = journal_add_journal_head(new_bh);	/* This sleeps */

	/*
	 * If a new transaction has already done a buffer copy-out, then
	 * we use that version of the data for the commit.
	 */
	jbd_lock_bh_state(bh_in);
repeat:
	if (jh_in->b_frozen_data) {
		done_copy_out = 1;
		new_page = virt_to_page(jh_in->b_frozen_data);
		new_offset = offset_in_page(jh_in->b_frozen_data);
	} else {
		new_page = jh2bh(jh_in)->b_page;
		new_offset = offset_in_page(jh2bh(jh_in)->b_data);
	}

	mapped_data = kmap_atomic(new_page);
	/*
	 * Check for escaping
	 */
	if (*((__be32 *)(mapped_data + new_offset)) ==
				cpu_to_be32(JFS_MAGIC_NUMBER)) {
		need_copy_out = 1;
		do_escape = 1;
	}
	kunmap_atomic(mapped_data);

	/*
	 * Do we need to do a data copy?
	 */
	if (need_copy_out && !done_copy_out) {
		char *tmp;

		jbd_unlock_bh_state(bh_in);
		tmp = jbd_alloc(bh_in->b_size, GFP_NOFS);
		jbd_lock_bh_state(bh_in);
		if (jh_in->b_frozen_data) {
			jbd_free(tmp, bh_in->b_size);
			goto repeat;
		}

		jh_in->b_frozen_data = tmp;
		mapped_data = kmap_atomic(new_page);
		memcpy(tmp, mapped_data + new_offset, jh2bh(jh_in)->b_size);
		kunmap_atomic(mapped_data);

		new_page = virt_to_page(tmp);
		new_offset = offset_in_page(tmp);
		done_copy_out = 1;
	}

	/*
	 * Did we need to do an escaping?  Now we've done all the
	 * copying, we can finally do so.
	 */
	if (do_escape) {
		mapped_data = kmap_atomic(new_page);
		*((unsigned int *)(mapped_data + new_offset)) = 0;
		kunmap_atomic(mapped_data);
	}

	set_bh_page(new_bh, new_page, new_offset);
	new_jh->b_transaction = NULL;
	new_bh->b_size = jh2bh(jh_in)->b_size;
	new_bh->b_bdev = transaction->t_journal->j_dev;
	new_bh->b_blocknr = blocknr;
	set_buffer_mapped(new_bh);
	set_buffer_dirty(new_bh);

	*jh_out = new_jh;

	/*
	 * The to-be-written buffer needs to get moved to the io queue,
	 * and the original buffer whose contents we are shadowing or
	 * copying is moved to the transaction's shadow queue.
	 */
	JBUFFER_TRACE(jh_in, "file as BJ_Shadow");
	spin_lock(&journal->j_list_lock);
	__journal_file_buffer(jh_in, transaction, BJ_Shadow);
	spin_unlock(&journal->j_list_lock);
	jbd_unlock_bh_state(bh_in);

	JBUFFER_TRACE(new_jh, "file as BJ_IO");
	journal_file_buffer(new_jh, transaction, BJ_IO);

	return do_escape | (done_copy_out << 1);
}
Пример #25
0
static int nilfs_cpfile_set_snapshot(struct inode *cpfile, __u64 cno)
{
	struct buffer_head *header_bh, *curr_bh, *prev_bh, *cp_bh;
	struct nilfs_cpfile_header *header;
	struct nilfs_checkpoint *cp;
	struct nilfs_snapshot_list *list;
	__u64 curr, prev;
	unsigned long curr_blkoff, prev_blkoff;
	void *kaddr;
	int ret;

	if (cno == 0)
		return -ENOENT; /* checkpoint number 0 is invalid */
	down_write(&NILFS_MDT(cpfile)->mi_sem);

	ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
	if (ret < 0)
		goto out_sem;
	kaddr = kmap_atomic(cp_bh->b_page);
	cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
	if (nilfs_checkpoint_invalid(cp)) {
		ret = -ENOENT;
		kunmap_atomic(kaddr);
		goto out_cp;
	}
	if (nilfs_checkpoint_snapshot(cp)) {
		ret = 0;
		kunmap_atomic(kaddr);
		goto out_cp;
	}
	kunmap_atomic(kaddr);

	ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
	if (ret < 0)
		goto out_cp;
	kaddr = kmap_atomic(header_bh->b_page);
	header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
	list = &header->ch_snapshot_list;
	curr_bh = header_bh;
	get_bh(curr_bh);
	curr = 0;
	curr_blkoff = 0;
	prev = le64_to_cpu(list->ssl_prev);
	while (prev > cno) {
		prev_blkoff = nilfs_cpfile_get_blkoff(cpfile, prev);
		curr = prev;
		if (curr_blkoff != prev_blkoff) {
			kunmap_atomic(kaddr);
			brelse(curr_bh);
			ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr,
								0, &curr_bh);
			if (ret < 0)
				goto out_header;
			kaddr = kmap_atomic(curr_bh->b_page);
		}
		curr_blkoff = prev_blkoff;
		cp = nilfs_cpfile_block_get_checkpoint(
			cpfile, curr, curr_bh, kaddr);
		list = &cp->cp_snapshot_list;
		prev = le64_to_cpu(list->ssl_prev);
	}
	kunmap_atomic(kaddr);

	if (prev != 0) {
		ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0,
							&prev_bh);
		if (ret < 0)
			goto out_curr;
	} else {
		prev_bh = header_bh;
		get_bh(prev_bh);
	}

	kaddr = kmap_atomic(curr_bh->b_page);
	list = nilfs_cpfile_block_get_snapshot_list(
		cpfile, curr, curr_bh, kaddr);
	list->ssl_prev = cpu_to_le64(cno);
	kunmap_atomic(kaddr);

	kaddr = kmap_atomic(cp_bh->b_page);
	cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
	cp->cp_snapshot_list.ssl_next = cpu_to_le64(curr);
	cp->cp_snapshot_list.ssl_prev = cpu_to_le64(prev);
	nilfs_checkpoint_set_snapshot(cp);
	kunmap_atomic(kaddr);

	kaddr = kmap_atomic(prev_bh->b_page);
	list = nilfs_cpfile_block_get_snapshot_list(
		cpfile, prev, prev_bh, kaddr);
	list->ssl_next = cpu_to_le64(cno);
	kunmap_atomic(kaddr);

	kaddr = kmap_atomic(header_bh->b_page);
	header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
	le64_add_cpu(&header->ch_nsnapshots, 1);
	kunmap_atomic(kaddr);

	mark_buffer_dirty(prev_bh);
	mark_buffer_dirty(curr_bh);
	mark_buffer_dirty(cp_bh);
	mark_buffer_dirty(header_bh);
	nilfs_mdt_mark_dirty(cpfile);

	brelse(prev_bh);

 out_curr:
	brelse(curr_bh);

 out_header:
	brelse(header_bh);

 out_cp:
	brelse(cp_bh);

 out_sem:
	up_write(&NILFS_MDT(cpfile)->mi_sem);
	return ret;
}
/*
 * Clear the user page.  No aliasing to deal with so we can just
 * attack the kernel's existing mapping of this page.
 */
static void v6_clear_user_highpage_nonaliasing(struct page *page, unsigned long vaddr)
{
    void *kaddr = kmap_atomic(page, KM_USER0);
    clear_page(kaddr);
    kunmap_atomic(kaddr, KM_USER0);
}
/*
 * netvsc_recv_callback -  Callback when we receive a packet from the
 * "wire" on the specified device.
 */
static int netvsc_recv_callback(struct hv_device *device_obj,
				struct hv_netvsc_packet *packet)
{
	struct vm_device *device_ctx = to_vm_device(device_obj);
	struct net_device *net = dev_get_drvdata(&device_ctx->device);
	struct sk_buff *skb;
	void *data;
	int i;
	unsigned long flags;

	DPRINT_ENTER(NETVSC_DRV);

	if (!net) {
		DPRINT_ERR(NETVSC_DRV, "got receive callback but net device "
				"not initialized yet");
		return 0;
	}

	/* Allocate a skb - TODO direct I/O to pages? */
	skb = netdev_alloc_skb_ip_align(net, packet->TotalDataBufferLength);
	if (unlikely(!skb)) {
		++net->stats.rx_dropped;
		return 0;
	}

	/* for kmap_atomic */
	local_irq_save(flags);

	/*
	 * Copy to skb. This copy is needed here since the memory pointed by
	 * hv_netvsc_packet cannot be deallocated
	 */
	for (i = 0; i < packet->PageBufferCount; i++) {
		data = kmap_atomic(pfn_to_page(packet->PageBuffers[i].Pfn),
					       KM_IRQ1);
		data = (void *)(unsigned long)data +
				packet->PageBuffers[i].Offset;

		memcpy(skb_put(skb, packet->PageBuffers[i].Length), data,
		       packet->PageBuffers[i].Length);

		kunmap_atomic((void *)((unsigned long)data -
				       packet->PageBuffers[i].Offset), KM_IRQ1);
	}

	local_irq_restore(flags);

	skb->protocol = eth_type_trans(skb, net);
	skb->ip_summed = CHECKSUM_NONE;

	net->stats.rx_packets++;
	net->stats.rx_bytes += skb->len;

	/*
	 * Pass the skb back up. Network stack will deallocate the skb when it
	 * is done.
	 * TODO - use NAPI?
	 */
	netif_rx(skb);

	DPRINT_DBG(NETVSC_DRV, "# of recvs %lu total size %lu",
		   net->stats.rx_packets, net->stats.rx_bytes);

	DPRINT_EXIT(NETVSC_DRV);

	return 0;
}
Пример #28
0
static inline void __clear_user_highpage(struct page *page, unsigned long vaddr)
{
	void *kaddr = kmap_atomic(page);
	clear_page(kaddr);
	kunmap_atomic(kaddr);
}
Пример #29
0
/* attempts to compress and store an single page */
static int zswap_frontswap_store(unsigned type, pgoff_t offset,
				struct page *page)
{
	struct zswap_tree *tree = zswap_trees[type];
	struct zswap_entry *entry, *dupentry;
	int ret;
	unsigned int dlen = PAGE_SIZE, len;
	unsigned long handle;
	char *buf;
	u8 *src, *dst;
	struct zswap_header *zhdr;

	if (!tree) {
		ret = -ENODEV;
		goto reject;
	}

	/* if this page got EIO on pageout before, give up immediately */
	if (PageError(page)) {
		ret = -ENOMEM;
		goto reject;
	}

	/* reclaim space if needed */
	if (zswap_is_full()) {
		zswap_pool_limit_hit++;
		if (zpool_shrink(zswap_pool, 1, NULL)) {
			zswap_reject_reclaim_fail++;
			ret = -ENOMEM;
			goto reject;
		}
	}

	/* allocate entry */
	entry = zswap_entry_cache_alloc(GFP_KERNEL);
	if (!entry) {
		zswap_reject_kmemcache_fail++;
		ret = -ENOMEM;
		goto reject;
	}

	/* compress */
	dst = get_cpu_var(zswap_dstmem);
	src = kmap_atomic(page);
	ret = zswap_comp_op(ZSWAP_COMPOP_COMPRESS, src, PAGE_SIZE, dst, &dlen);
	kunmap_atomic(src);
	if (ret) {
		ret = -EINVAL;
		goto freepage;
	}

	/* store */
	len = dlen + sizeof(struct zswap_header);
	ret = zpool_malloc(zswap_pool, len, __GFP_NORETRY | __GFP_NOWARN,
		&handle);
	if (ret == -ENOSPC) {
		zswap_reject_compress_poor++;
		goto freepage;
	}
	if (ret) {
		zswap_reject_alloc_fail++;
		goto freepage;
	}
	zhdr = zpool_map_handle(zswap_pool, handle, ZPOOL_MM_RW);
	zhdr->swpentry = swp_entry(type, offset);
	buf = (u8 *)(zhdr + 1);
	memcpy(buf, dst, dlen);
	zpool_unmap_handle(zswap_pool, handle);
	put_cpu_var(zswap_dstmem);

	/* populate entry */
	entry->offset = offset;
	entry->handle = handle;
	entry->length = dlen;

	/* map */
	spin_lock(&tree->lock);
	do {
		ret = zswap_rb_insert(&tree->rbroot, entry, &dupentry);
		if (ret == -EEXIST) {
			zswap_duplicate_entry++;
			/* remove from rbtree */
			zswap_rb_erase(&tree->rbroot, dupentry);
			zswap_entry_put(tree, dupentry);
		}
	} while (ret == -EEXIST);
	spin_unlock(&tree->lock);

	/* update stats */
	atomic_inc(&zswap_stored_pages);
	zswap_pool_total_size = zpool_get_total_size(zswap_pool);

	return 0;

freepage:
	put_cpu_var(zswap_dstmem);
	zswap_entry_cache_free(entry);
reject:
	return ret;
}
Пример #30
0
static int vmw_gmr_build_descriptors(struct list_head *desc_pages,
				     struct page *pages[],
				     unsigned long num_pages)
{
	struct page *page, *next;
	struct svga_guest_mem_descriptor *page_virtual = NULL;
	struct svga_guest_mem_descriptor *desc_virtual = NULL;
	unsigned int desc_per_page;
	unsigned long prev_pfn;
	unsigned long pfn;
	int ret;

	desc_per_page = PAGE_SIZE /
	    sizeof(struct svga_guest_mem_descriptor) - 1;

	while (likely(num_pages != 0)) {
		page = alloc_page(__GFP_HIGHMEM);
		if (unlikely(page == NULL)) {
			ret = -ENOMEM;
			goto out_err;
		}

		list_add_tail(&page->lru, desc_pages);

		/*
		 * Point previous page terminating descriptor to this
		 * page before unmapping it.
		 */

		if (likely(page_virtual != NULL)) {
			desc_virtual->ppn = page_to_pfn(page);
			kunmap_atomic(page_virtual, KM_USER0);
		}

		page_virtual = kmap_atomic(page, KM_USER0);
		desc_virtual = page_virtual - 1;
		prev_pfn = ~(0UL);

		while (likely(num_pages != 0)) {
			pfn = page_to_pfn(*pages);

			if (pfn != prev_pfn + 1) {

				if (desc_virtual - page_virtual ==
				    desc_per_page - 1)
					break;

				(++desc_virtual)->ppn = cpu_to_le32(pfn);
				desc_virtual->num_pages = cpu_to_le32(1);
			} else {
				uint32_t tmp =
				    le32_to_cpu(desc_virtual->num_pages);
				desc_virtual->num_pages = cpu_to_le32(tmp + 1);
			}
			prev_pfn = pfn;
			--num_pages;
			++pages;
		}

		(++desc_virtual)->ppn = cpu_to_le32(0);
		desc_virtual->num_pages = cpu_to_le32(0);
	}

	if (likely(page_virtual != NULL))
		kunmap_atomic(page_virtual, KM_USER0);

	return 0;
out_err:
	list_for_each_entry_safe(page, next, desc_pages, lru) {
		list_del_init(&page->lru);
		__free_page(page);
	}