Commit 1fa40b01 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Tim Shimmin
Browse files

[XFS] Only use refcounted pages for I/O 



Many block drivers (aoe, iscsi) really want refcountable pages in bios,
which is what almost everyone send down. XFS unfortunately has a few
places where it sends down buffers that may come from kmalloc, which
breaks them.

Fix the places that use kmalloc()d buffers.

SGI-PV: 964546
SGI-Modid: xfs-linux-melb:xfs-kern:28562a

Signed-Off-By: default avatarChristoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarDavid Chinner <dgc@sgi.com>
Signed-off-by: default avatarTim Shimmin <tes@sgi.com>
parent 4eb6bf6b

fs/xfs/linux-2.6/xfs_buf.c

+21 −28
Original line number Diff line number Diff line
@@ -314,7 +314,7 @@ xfs_buf_free( 


	ASSERT(list_empty(&bp->b_hash_list));



	if (bp->b_flags & _XBF_PAGE_CACHE) {

	if (bp->b_flags & (_XBF_PAGE_CACHE|_XBF_PAGES)) {

		uint		i;



		if ((bp->b_flags & XBF_MAPPED) && (bp->b_page_count > 1))
@@ -323,18 +323,11 @@ xfs_buf_free( 
		for (i = 0; i < bp->b_page_count; i++) {

			struct page	*page = bp->b_pages[i];



			if (bp->b_flags & _XBF_PAGE_CACHE)

				ASSERT(!PagePrivate(page));

			page_cache_release(page);

		}

		_xfs_buf_free_pages(bp);

	} else if (bp->b_flags & _XBF_KMEM_ALLOC) {

		 /*

		  * XXX(hch): bp->b_count_desired might be incorrect (see

		  * xfs_buf_associate_memory for details), but fortunately

		  * the Linux version of kmem_free ignores the len argument..

		  */

		kmem_free(bp->b_addr, bp->b_count_desired);

		_xfs_buf_free_pages(bp);

	}



	xfs_buf_deallocate(bp);
@@ -764,41 +757,41 @@ xfs_buf_get_noaddr( 
	size_t			len,

	xfs_buftarg_t		*target)

{

	size_t			malloc_len = len;

	unsigned long		page_count = PAGE_ALIGN(len) >> PAGE_SHIFT;

	int			error, i;

	xfs_buf_t		*bp;

	void			*data;

	int			error;



	bp = xfs_buf_allocate(0);

	if (unlikely(bp == NULL))

		goto fail;

	_xfs_buf_initialize(bp, target, 0, len, 0);



 try_again:

	data = kmem_alloc(malloc_len, KM_SLEEP | KM_MAYFAIL | KM_LARGE);

	if (unlikely(data == NULL))

	error = _xfs_buf_get_pages(bp, page_count, 0);

	if (error)

		goto fail_free_buf;



	/* check whether alignment matches.. */

	if ((__psunsigned_t)data !=

	    ((__psunsigned_t)data & ~target->bt_smask)) {

		/* .. else double the size and try again */

		kmem_free(data, malloc_len);

		malloc_len <<= 1;

		goto try_again;

	for (i = 0; i < page_count; i++) {

		bp->b_pages[i] = alloc_page(GFP_KERNEL);

		if (!bp->b_pages[i])

			goto fail_free_mem;

	}

	bp->b_flags |= _XBF_PAGES;



	error = xfs_buf_associate_memory(bp, data, len);

	if (error)

	error = _xfs_buf_map_pages(bp, XBF_MAPPED);

	if (unlikely(error)) {

		printk(KERN_WARNING "%s: failed to map pages\n",

				__FUNCTION__);

		goto fail_free_mem;

	bp->b_flags |= _XBF_KMEM_ALLOC;

	}



	xfs_buf_unlock(bp);



	XB_TRACE(bp, "no_daddr", data);

	XB_TRACE(bp, "no_daddr", len);

	return bp;



 fail_free_mem:

	kmem_free(data, malloc_len);

	while (--i >= 0)

		__free_page(bp->b_pages[i]);

 fail_free_buf:

	xfs_buf_free(bp);

 fail:

fs/xfs/linux-2.6/xfs_buf.h

+1 −1
Original line number Diff line number Diff line
@@ -63,7 +63,7 @@ typedef enum { 


	/* flags used only internally */

	_XBF_PAGE_CACHE = (1 << 17),/* backed by pagecache		   */

	_XBF_KMEM_ALLOC = (1 << 18),/* backed by kmem_alloc()		   */

	_XBF_PAGES = (1 << 18),	    /* backed by refcounted pages	   */

	_XBF_RUN_QUEUES = (1 << 19),/* run block device task queue	   */

	_XBF_DELWRI_Q = (1 << 21),   /* buffer on delwri queue		   */

} xfs_buf_flags_t;

fs/xfs/xfs_log.c

+10 −9
Original line number Diff line number Diff line
@@ -1199,11 +1199,18 @@ xlog_alloc_log(xfs_mount_t *mp, 
		*iclogp = (xlog_in_core_t *)

			  kmem_zalloc(sizeof(xlog_in_core_t), KM_SLEEP);

		iclog = *iclogp;

		iclog->hic_data = (xlog_in_core_2_t *)

			  kmem_zalloc(iclogsize, KM_SLEEP | KM_LARGE);



		iclog->ic_prev = prev_iclog;

		prev_iclog = iclog;



		bp = xfs_buf_get_noaddr(log->l_iclog_size, mp->m_logdev_targp);

		if (!XFS_BUF_CPSEMA(bp))

			ASSERT(0);

		XFS_BUF_SET_IODONE_FUNC(bp, xlog_iodone);

		XFS_BUF_SET_BDSTRAT_FUNC(bp, xlog_bdstrat_cb);

		XFS_BUF_SET_FSPRIVATE2(bp, (unsigned long)1);

		iclog->ic_bp = bp;

		iclog->hic_data = bp->b_addr;



		log->l_iclog_bak[i] = (xfs_caddr_t)&(iclog->ic_header);



		head = &iclog->ic_header;
@@ -1216,11 +1223,6 @@ xlog_alloc_log(xfs_mount_t *mp, 
		INT_SET(head->h_fmt, ARCH_CONVERT, XLOG_FMT);

		memcpy(&head->h_fs_uuid, &mp->m_sb.sb_uuid, sizeof(uuid_t));



		bp = xfs_buf_get_empty(log->l_iclog_size, mp->m_logdev_targp);

		XFS_BUF_SET_IODONE_FUNC(bp, xlog_iodone);

		XFS_BUF_SET_BDSTRAT_FUNC(bp, xlog_bdstrat_cb);

		XFS_BUF_SET_FSPRIVATE2(bp, (unsigned long)1);

		iclog->ic_bp = bp;



		iclog->ic_size = XFS_BUF_SIZE(bp) - log->l_iclog_hsize;

		iclog->ic_state = XLOG_STATE_ACTIVE;
@@ -1528,7 +1530,6 @@ xlog_dealloc_log(xlog_t *log) 
		}

#endif

		next_iclog = iclog->ic_next;

		kmem_free(iclog->hic_data, log->l_iclog_size);

		kmem_free(iclog, sizeof(xlog_in_core_t));

		iclog = next_iclog;

	}

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