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target: Drop arbitrary maximum I/O size limit

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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 <lance.gropper@qosserver.com>
Reported-by: Stefan Priebe <s.priebe@profihost.ag>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: stable@vger.kernel.org # 3.4
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Nicholas Bellinger 2015-01-06 16:10:37 -08:00
parent 67e51daa50
commit 046ba64285
5 changed files with 16 additions and 25 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
drivers/target/target_core_device.c
View file

@ -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();

11
drivers/target/target_core_file.c
View file

@ -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.

2
drivers/target/target_core_iblock.c
View file

@ -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;
/*

15
drivers/target/target_core_sbc.c
View file

@ -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) {

5
drivers/target/target_core_spc.c
View file

@ -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