Assume target names are URL encoded with '%' as the special character.
Any sequence of '%' followed by two bytes in the target name will be replaced
with the byte that the second two bytes represent in hexadecimal.
Example
iqn.ronnie.test%3A1234
will be translated to iqn.ronnie.test:1234
Default to 0 meaning no timeout.
Implement a test for iSCS to test what happens if we send a command
with CMDSN being higher than the target allows.
In this case we dont strictly know what will happen, just that what should
NOT happen is the target responding with success.
But we have to be prepared for any kind of failure, including a timeout,
scsi sense, or even iscsi reject or session failure.
iscsi_data.size is used as parameter to memory
operation functions (such as malloc) which except
size_t rather than int.
Signed-off-by: Peter Lieven <pl@kamp.de>
Add support for BUSY status coide from the target and just pass this
back to the application as is (instead of converting it to _ERROR).
This allows the application to trap task->status==SCSI_STATUS_BUSY and
decide what/how to proceed.
This patch adds the abilitiy to libiscsi to count the number
of consecutive outstanding NOPs.
With this ability its fairly easy to implement a keepalive
check with NOPs in your application.
Periodically (e.g. every 5 secs) create a NOP-Out with:
iscsi_nop_out_async(iscsi, NULL, NULL, 0, NULL);
At that time check the number of consecutive missing NOP-Ins
with
iscsi_get_nops_in_flight(iscsi) > N.
Where N is the number of missing NOP-Ins you will allow.
Please note that it is legitime for the Target to ignore
a NOP if the load is very high as those packet are mark
as IMMEDIATE.
Signed-off-by: Peter Lieven <pl@kamp.de>
In specific situation it might be useful to give up if a reconnect
is not successful or after a given number reconnect retries.
This patch adds the ability to change that. The default remains
the same: retry forever.
Signed-off-by: Peter Lieven <pl@kamp.de>
As part of the test also validate the PDU that libiscsi generates and verify that
1, the PDU we send has the F flag set
2, that datasegmentlength for the PDU is one block
This patch defines an scsi_iovec struct which is guaranteed
to be POSIX compatible. It furthermore adds support for
in+out iovectors for bi-directional operations
Signed-off-by: Peter Lieven <pl@kamp.de>
If an application passes buffers to libiscsi for reading they are
currently added to a linked list one by one. This leads to a malloc
for each buffer object plus O(n) walks trough the list to add
the buffer to then end of the list. Additionally the buffer read
routine takes up to O(n) iterations to find the right buffer
for a request.
This patch introduces an scsi_iovector struct to pass buffers to
an scsi task. Adding a new buffer is in O(1) and finding the
right buffer to also. Malloc requirements are in O(log(n)).
Additionally the scsi_iovector struct is itended to be binary
compatible to an QEMUIOVector allowing to pass this structure
directly to the library.
Initial tests have been made booting an Ubuntu LTS 12.04.1
Desktop server up to the login prompt. The following observations
have been made with regards to scsi_malloc calls:
original implementation: ~11.500 mallocs
using iovector instead of list: ~ 7.500 mallocs
passing the iovector directly: 0 mallocs
To enable this feature in qemu for testing the following patch might
be used:
diff --git a/block/iscsi.c b/block/iscsi.c
index a6a819d..2809c15 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -390,11 +390,16 @@ iscsi_aio_readv(BlockDriverState *bs, int64_t sector_num,
return NULL;
}
+#if defined(LIBISCSI_FEATURE_IOVECTOR)
+ assert(sizeof(struct QEMUIOVector) == sizeof(struct scsi_iovector));
+ scsi_iovector_assign(acb->task, (struct scsi_iovector*) acb->qiov);
+#else
for (i = 0; i < acb->qiov->niov; i++) {
scsi_task_add_data_in_buffer(acb->task,
acb->qiov->iov[i].iov_len,
acb->qiov->iov[i].iov_base);
}
+#endif
iscsi_set_events(iscsilun);
---
Signed-off-by: Peter Lieven <pl@kamp.de>
The memory tracking code reports memory allocated by iscsi_allocate_pdu_with_itt_flags_size() as lost.
This memory is allocated by the iscsi part of libiscsi, but later freed by the lowlevel scsi part. We
will fix this later by introducing an iscsi_task object.
These two functions belong in the iscsi layer, not the scsi layer so move them
out from scsi-lowlevel.c so that we can start turning scsi-lowlevel.c to a pure
scsi layer and remove all dependencies to iscsi from it.
DPRINTF was blindly sending all debug output to fd 2 (stderr).
The new function iscsi_set_debug_fd() will set the debug fd.
In general debugging is completely disabled by default.
This patch adds logarithmic malloc behaviour to iscsi_add_data().
Currently for each new call there is a new buffer allocated
and all old data is copied to the new buffer. Change this by
allocating at least PAGE_SIZE bytes and increase the allocation
by powers of 2 each time it does no longer fit.
This patch adds a wrapper around all memory allocations and frees.
The idea is to get warned immediately if the application leaks memory.
Additionally the wrapper functions make it easy to add different
memory allocators or memory pools in the future.
This patch adds 3 functions to set the 3 keepalive values TCP_KEEPIDLE, TCP_KEEPCNT
and TCP_KEEPINTVL. The values have to be set after iscsi context creation and are
then configured on the socket on each new connection.
This patch adds a user configurable option to set the TCP_USER_TIMEOUT
socket option. With this timeout set a broken TCP session is shutdown
after a given timeout even there are unacked packets. SO_KEEPALIVE
seems not to work in this case.
