From 046ba64285a4389ae5e9a7dfa253c6bff3d7c341 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Tue, 6 Jan 2015 16:10:37 -0800 Subject: [PATCH] target: Drop arbitrary maximum I/O size limit This patch drops the arbitrary maximum I/O size limit in sbc_parse_cdb(), which currently for fabric_max_sectors is hardcoded to 8192 (4 MB for 512 byte sector devices), and for hw_max_sectors is a backend driver dependent value. This limit is problematic because Linux initiators have only recently started to honor block limits MAXIMUM TRANSFER LENGTH, and other non-Linux based initiators (eg: MSFT Fibre Channel) can also generate I/Os larger than 4 MB in size. Currently when this happens, the following message will appear on the target resulting in I/Os being returned with non recoverable status: SCSI OP 28h with too big sectors 16384 exceeds fabric_max_sectors: 8192 Instead, drop both [fabric,hw]_max_sector checks in sbc_parse_cdb(), and convert the existing hw_max_sectors into a purely informational attribute used to represent the granuality that backend driver and/or subsystem code is splitting I/Os upon. Also, update FILEIO with an explicit FD_MAX_BYTES check in fd_execute_rw() to deal with the one special iovec limitiation case. v2 changes: - Drop hw_max_sectors check in sbc_parse_cdb() Reported-by: Lance Gropper Reported-by: Stefan Priebe Cc: Christoph Hellwig Cc: Martin K. Petersen Cc: Roland Dreier Cc: stable@vger.kernel.org # 3.4 Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_device.c | 8 ++++---- drivers/target/target_core_file.c | 11 ++++++++++- drivers/target/target_core_iblock.c | 2 +- drivers/target/target_core_sbc.c | 15 --------------- drivers/target/target_core_spc.c | 5 +---- 5 files changed, 16 insertions(+), 25 deletions(-) diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index 7653cfb027a2..ee4b89fb8841 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -1156,10 +1156,10 @@ int se_dev_set_optimal_sectors(struct se_device *dev, u32 optimal_sectors) dev, dev->export_count); return -EINVAL; } - if (optimal_sectors > dev->dev_attrib.fabric_max_sectors) { + if (optimal_sectors > dev->dev_attrib.hw_max_sectors) { pr_err("dev[%p]: Passed optimal_sectors %u cannot be" - " greater than fabric_max_sectors: %u\n", dev, - optimal_sectors, dev->dev_attrib.fabric_max_sectors); + " greater than hw_max_sectors: %u\n", dev, + optimal_sectors, dev->dev_attrib.hw_max_sectors); return -EINVAL; } @@ -1554,7 +1554,6 @@ struct se_device *target_alloc_device(struct se_hba *hba, const char *name) DA_UNMAP_GRANULARITY_ALIGNMENT_DEFAULT; dev->dev_attrib.max_write_same_len = DA_MAX_WRITE_SAME_LEN; dev->dev_attrib.fabric_max_sectors = DA_FABRIC_MAX_SECTORS; - dev->dev_attrib.optimal_sectors = DA_FABRIC_MAX_SECTORS; xcopy_lun = &dev->xcopy_lun; xcopy_lun->lun_se_dev = dev; @@ -1595,6 +1594,7 @@ int target_configure_device(struct se_device *dev) dev->dev_attrib.hw_max_sectors = se_dev_align_max_sectors(dev->dev_attrib.hw_max_sectors, dev->dev_attrib.hw_block_size); + dev->dev_attrib.optimal_sectors = dev->dev_attrib.hw_max_sectors; dev->dev_index = scsi_get_new_index(SCSI_DEVICE_INDEX); dev->creation_time = get_jiffies_64(); diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c index c2aea099ea4a..b09021135c3b 100644 --- a/drivers/target/target_core_file.c +++ b/drivers/target/target_core_file.c @@ -621,7 +621,16 @@ fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, struct fd_prot fd_prot; sense_reason_t rc; int ret = 0; - + /* + * We are currently limited by the number of iovecs (2048) per + * single vfs_[writev,readv] call. + */ + if (cmd->data_length > FD_MAX_BYTES) { + pr_err("FILEIO: Not able to process I/O of %u bytes due to" + "FD_MAX_BYTES: %u iovec count limitiation\n", + cmd->data_length, FD_MAX_BYTES); + return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + } /* * Call vectorized fileio functions to map struct scatterlist * physical memory addresses to struct iovec virtual memory. diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c index 3efff94fbd97..5795cd8ab5d9 100644 --- a/drivers/target/target_core_iblock.c +++ b/drivers/target/target_core_iblock.c @@ -124,7 +124,7 @@ static int iblock_configure_device(struct se_device *dev) q = bdev_get_queue(bd); dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd); - dev->dev_attrib.hw_max_sectors = UINT_MAX; + dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q); dev->dev_attrib.hw_queue_depth = q->nr_requests; /* diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c index 11bea1952435..cd4bed7b2757 100644 --- a/drivers/target/target_core_sbc.c +++ b/drivers/target/target_core_sbc.c @@ -953,21 +953,6 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) { unsigned long long end_lba; - - if (sectors > dev->dev_attrib.fabric_max_sectors) { - printk_ratelimited(KERN_ERR "SCSI OP %02xh with too" - " big sectors %u exceeds fabric_max_sectors:" - " %u\n", cdb[0], sectors, - dev->dev_attrib.fabric_max_sectors); - return TCM_INVALID_CDB_FIELD; - } - if (sectors > dev->dev_attrib.hw_max_sectors) { - printk_ratelimited(KERN_ERR "SCSI OP %02xh with too" - " big sectors %u exceeds backend hw_max_sectors:" - " %u\n", cdb[0], sectors, - dev->dev_attrib.hw_max_sectors); - return TCM_INVALID_CDB_FIELD; - } check_lba: end_lba = dev->transport->get_blocks(dev) + 1; if (cmd->t_task_lba + sectors > end_lba) { diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c index 1307600fe726..4c71657da56a 100644 --- a/drivers/target/target_core_spc.c +++ b/drivers/target/target_core_spc.c @@ -505,7 +505,6 @@ static sense_reason_t spc_emulate_evpd_b0(struct se_cmd *cmd, unsigned char *buf) { struct se_device *dev = cmd->se_dev; - u32 max_sectors; int have_tp = 0; int opt, min; @@ -539,9 +538,7 @@ spc_emulate_evpd_b0(struct se_cmd *cmd, unsigned char *buf) /* * Set MAXIMUM TRANSFER LENGTH */ - max_sectors = min(dev->dev_attrib.fabric_max_sectors, - dev->dev_attrib.hw_max_sectors); - put_unaligned_be32(max_sectors, &buf[8]); + put_unaligned_be32(dev->dev_attrib.hw_max_sectors, &buf[8]); /* * Set OPTIMAL TRANSFER LENGTH -- 2.20.1