This is the basic support for doing i/o in a separate worker thread.
It is still not threads safe but a start.
Now we need to protect all variables such as outqueue, waitpdu
and friends.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
When an iSCSI connection enters the reconnection phase, the backoff
time (next_reconnect) increases with reconnection retry_cnt. However,
if the client detects that the target has recovered before reaching
next_reconnect, calling iscsi_reconnect/iscsi_force_reconnect has no
any effect, making fast reconnection impossible.
This patch introduces an interface to reset next_reconnect, so that
the client can reset the backoff time upon detecting target recovery
and achieve faster reconnection.
Resolves: https://github.com/sahlberg/libiscsi/issues/428
Signed-off-by: raywang <honglei.wang@smartx.com>
If a connection attempt is hung, then iscsi_reconnect() won't do anything. This
makes sense if we'd just re-try to connect to the same target, but if (for
example) login redirect might point us to a different, healthy, target, it
should be possible to restart the full connection process on request.
Signed-off-by: John Levon <john.levon@nutanix.com>
Build on existing scsi_cdb_extended_copy() functionality. This operation
can be used to offload inter and intra LU copies to the target.
The API is rather primitive, in that the caller needs to construct the
parameter buffer, including CSCD and segment descriptor lists, etc.
Signed-off-by: David Disseldorp <ddiss@suse.de>
Build on existing scsi_cdb_receive_copy_results() functionality. This
request is most commonly used to determine target-side EXTENDED COPY
operational parameters.
Signed-off-by: David Disseldorp <ddiss@suse.de>
Remove iscsi_queue_pdu from the list of symbols otherwise clang on OSX
fails to compile with the following error:
Undefined symbols for architecture x86_64:
"_iscsi_queue_pdu", referenced from:
-exported_symbol[s_list] command line option
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
iscsi-command: Adding new functions for all write operations (WRITE10,
WRITE12, WRITE16, WRITEOR, etc') for cases where the user wants
to pass his own io vectors (prevent memcpy).
new functions are called iscsi_write*_iov_task and looks
very similar to the iscsi_write*_task, only they get
scsi_iovec pointer and number of scsi_iovec as
parameters.
Change-Id: I719552b4cbda4f937975b5df7e77b4844e48cd16
Signed-off-by: Roy Shterman <roysh@mellanox.com>
lib/init: initializing connection transport
lib/socket: Adding function to initialize tcp transport.
future commits will include adding iSER transport layer,
so each transport option will has it's own template of functions.
all_utils: All utils stay the same, in future iSER commits in case of
iSER transport we will override tcp_transport in
iscsi_context.
connect: adding transport initialization when creating context
include/iscsi-private: Adding iscsi_transport attribute in iscsi_context
Signed-off-by: Roy Shterman <roysh@mellanox.com>
Make iscsi_init_tcp_transport private
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
This function allows the caller to determine the number of PDUs queued
for transmission for a given iscsi context.
Signed-off-by: David Disseldorp <ddiss@suse.de>
Normal applications want the current behaviour where we have the library
consume any/all of the UnitAttentions that the target may have queued on the
initial connection, but when we reconnect the session after a failure the
library will pass all the UAs back to the application to process.
Some applications, such as the test suite or really trivial applications
might not want to have to deal with handling of UAs and just "make it work".
Those applications can now request that upon any reconnection of the session
that libiscsi will automatically consume any and all UAs and hide them from
the application.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Extend struct scsi_sense with sense specific descriptor information,
introduce the function scsi_parse_sense_data() and let that function
parse the sense specific descriptor.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Disable memory caching in libiscsi if the environment variable
LIBISCSI_CACHE_ALLOCATIONS has been set to zero. This makes
Valgrind reports more meaningful.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
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.
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>
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>
