From c836777830428372074d5129ac513e1472c99791 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Mon, 13 Apr 2015 23:21:57 +0900 Subject: [PATCH] target/file: Fix SG table for prot_buf initialization In fd_do_prot_rw(), it allocates prot_buf which is used to copy from se_cmd->t_prot_sg by sbc_dif_copy_prot(). The SG table for prot_buf is also initialized by allocating 'se_cmd->t_prot_nents' entries of scatterlist and setting the data length of each entry to PAGE_SIZE at most. However if se_cmd->t_prot_sg contains a clustered entry (i.e. sg->length > PAGE_SIZE), the SG table for prot_buf can't be initialized correctly and sbc_dif_copy_prot() can't copy to prot_buf. (This actually happened with TCM loopback fabric module) As prot_buf is allocated by kzalloc() and it's physically contiguous, we only need a single scatterlist entry. Signed-off-by: Akinobu Mita Cc: Sagi Grimberg Cc: "Martin K. Petersen" Cc: Christoph Hellwig Cc: "James E.J. Bottomley" Cc: # v3.14+ Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_file.c | 21 ++++++--------------- 1 file changed, 6 insertions(+), 15 deletions(-) diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c index 3dcfc73528ec..1284fec63db8 100644 --- a/drivers/target/target_core_file.c +++ b/drivers/target/target_core_file.c @@ -264,11 +264,10 @@ static int fd_do_prot_rw(struct se_cmd *cmd, struct fd_prot *fd_prot, struct se_device *se_dev = cmd->se_dev; struct fd_dev *dev = FD_DEV(se_dev); struct file *prot_fd = dev->fd_prot_file; - struct scatterlist *sg; loff_t pos = (cmd->t_task_lba * se_dev->prot_length); unsigned char *buf; - u32 prot_size, len, size; - int rc, ret = 1, i; + u32 prot_size; + int rc, ret = 1; prot_size = (cmd->data_length / se_dev->dev_attrib.block_size) * se_dev->prot_length; @@ -281,24 +280,16 @@ static int fd_do_prot_rw(struct se_cmd *cmd, struct fd_prot *fd_prot, } buf = fd_prot->prot_buf; - fd_prot->prot_sg_nents = cmd->t_prot_nents; - fd_prot->prot_sg = kzalloc(sizeof(struct scatterlist) * - fd_prot->prot_sg_nents, GFP_KERNEL); + fd_prot->prot_sg_nents = 1; + fd_prot->prot_sg = kzalloc(sizeof(struct scatterlist), + GFP_KERNEL); if (!fd_prot->prot_sg) { pr_err("Unable to allocate fd_prot->prot_sg\n"); kfree(fd_prot->prot_buf); return -ENOMEM; } sg_init_table(fd_prot->prot_sg, fd_prot->prot_sg_nents); - size = prot_size; - - for_each_sg(fd_prot->prot_sg, sg, fd_prot->prot_sg_nents, i) { - - len = min_t(u32, PAGE_SIZE, size); - sg_set_buf(sg, buf, len); - size -= len; - buf += len; - } + sg_set_buf(fd_prot->prot_sg, buf, prot_size); } if (is_write) { -- 2.39.2