Commit 5a01d082 authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

vhost/scsi: Move sanity check into vhost_scsi_map_iov_to_sgl 



Move the overflow check for sgl_count > TCM_VHOST_PREALLOC_SGLS into
vhost_scsi_map_iov_to_sgl() so that it's based on the total number
of SGLs for all IOVs, instead of single IOVs.

Also, rename TCM_VHOST_PREALLOC_PAGES -> TCM_VHOST_PREALLOC_UPAGES
to better describe pointers to user-space pages.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 1b49dcf3

drivers/vhost/scsi.c

+25 −34
Original line number Diff line number Diff line
@@ -57,7 +57,7 @@ 
#define TCM_VHOST_MAX_CDB_SIZE 32

#define TCM_VHOST_DEFAULT_TAGS 256

#define TCM_VHOST_PREALLOC_SGLS 2048

#define TCM_VHOST_PREALLOC_PAGES 2048

#define TCM_VHOST_PREALLOC_UPAGES 2048



struct vhost_scsi_inflight {

	/* Wait for the flush operation to finish */
@@ -767,35 +767,28 @@ vhost_scsi_map_to_sgl(struct tcm_vhost_cmd *tv_cmd, 
		      struct scatterlist *sgl,

		      unsigned int sgl_count,

		      struct iovec *iov,

		      int write)

		      struct page **pages,

		      bool write)

{

	unsigned int npages = 0, pages_nr, offset, nbytes;

	struct scatterlist *sg = sgl;

	void __user *ptr = iov->iov_base;

	size_t len = iov->iov_len;

	struct page **pages;

	int ret, i;



	if (sgl_count > TCM_VHOST_PREALLOC_SGLS) {

		pr_err("vhost_scsi_map_to_sgl() psgl_count: %u greater than"

		       " preallocated TCM_VHOST_PREALLOC_SGLS: %u\n",

			sgl_count, TCM_VHOST_PREALLOC_SGLS);

		return -ENOBUFS;

	}



	pages_nr = iov_num_pages(iov);

	if (pages_nr > sgl_count)

	if (pages_nr > sgl_count) {

		pr_err("vhost_scsi_map_to_sgl() pages_nr: %u greater than"

		       " sgl_count: %u\n", pages_nr, sgl_count);

		return -ENOBUFS;



	if (pages_nr > TCM_VHOST_PREALLOC_PAGES) {

	}

	if (pages_nr > TCM_VHOST_PREALLOC_UPAGES) {

		pr_err("vhost_scsi_map_to_sgl() pages_nr: %u greater than"

		       " preallocated TCM_VHOST_PREALLOC_PAGES: %u\n",

			pages_nr, TCM_VHOST_PREALLOC_PAGES);

		       " preallocated TCM_VHOST_PREALLOC_UPAGES: %u\n",

			pages_nr, TCM_VHOST_PREALLOC_UPAGES);

		return -ENOBUFS;

	}



	pages = tv_cmd->tvc_upages;



	ret = get_user_pages_fast((unsigned long)ptr, pages_nr, write, pages);

	/* No pages were pinned */

	if (ret < 0)
@@ -825,33 +818,32 @@ out: 
static int

vhost_scsi_map_iov_to_sgl(struct tcm_vhost_cmd *cmd,

			  struct iovec *iov,

			  unsigned int niov,

			  int write)

			  int niov,

			  bool write)

{

	int ret;

	unsigned int i;

	u32 sgl_count;

	struct scatterlist *sg;

	struct scatterlist *sg = cmd->tvc_sgl;

	unsigned int sgl_count = 0;

	int ret, i;



	/*

	 * Find out how long sglist needs to be

	 */

	sgl_count = 0;

	for (i = 0; i < niov; i++)

		sgl_count += iov_num_pages(&iov[i]);



	/* TODO overflow checking */

	if (sgl_count > TCM_VHOST_PREALLOC_SGLS) {

		pr_err("vhost_scsi_map_iov_to_sgl() sgl_count: %u greater than"

			" preallocated TCM_VHOST_PREALLOC_SGLS: %u\n",

			sgl_count, TCM_VHOST_PREALLOC_SGLS);

		return -ENOBUFS;

	}



	sg = cmd->tvc_sgl;

	pr_debug("%s sg %p sgl_count %u\n", __func__, sg, sgl_count);

	sg_init_table(sg, sgl_count);



	cmd->tvc_sgl_count = sgl_count;



	pr_debug("Mapping %u iovecs for %u pages\n", niov, sgl_count);

	pr_debug("Mapping iovec %p for %u pages\n", &iov[0], sgl_count);



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

		ret = vhost_scsi_map_to_sgl(cmd, sg, sgl_count, &iov[i],

					    write);

					    cmd->tvc_upages, write);

		if (ret < 0) {

			for (i = 0; i < cmd->tvc_sgl_count; i++)

				put_page(sg_page(&cmd->tvc_sgl[i]));
@@ -859,7 +851,6 @@ vhost_scsi_map_iov_to_sgl(struct tcm_vhost_cmd *cmd, 
			cmd->tvc_sgl_count = 0;

			return ret;

		}



		sg += ret;

		sgl_count -= ret;

	}
@@ -1765,7 +1756,7 @@ static int tcm_vhost_make_nexus(struct tcm_vhost_tpg *tpg, 
		}



		tv_cmd->tvc_upages = kzalloc(sizeof(struct page *) *

					TCM_VHOST_PREALLOC_PAGES, GFP_KERNEL);

					TCM_VHOST_PREALLOC_UPAGES, GFP_KERNEL);

		if (!tv_cmd->tvc_upages) {

			mutex_unlock(&tpg->tv_tpg_mutex);

			pr_err("Unable to allocate tv_cmd->tvc_upages\n");

CRA Git | Maintained and supported by SUSTech CRA and CCSE