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author | 2015-01-06 16:10:37 -0800 | |
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committer | 2015-01-09 15:21:40 -0800 | |
commit | 046ba64285a4389ae5e9a7dfa253c6bff3d7c341 (patch) | |
tree | 8160b4c771df304f70cf7cfc155f6e7c152d0089 /drivers/target/target_core_file.c | |
parent | Documentation/target: Update fabric_ops to latest code (diff) | |
download | linux-046ba64285a4389ae5e9a7dfa253c6bff3d7c341.tar.gz linux-046ba64285a4389ae5e9a7dfa253c6bff3d7c341.tar.bz2 linux-046ba64285a4389ae5e9a7dfa253c6bff3d7c341.zip |
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 <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>
Diffstat (limited to 'drivers/target/target_core_file.c')
-rw-r--r-- | drivers/target/target_core_file.c | 11 |
1 files changed, 10 insertions, 1 deletions
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. |