The TEST UNIT READY command is issued automatically when the device is
opened, and is not the result of a command being issued by the caller.
This is required in order that a permanent TEST UNIT READY failure can
be used to identify unusable paths in a multipath SAN device.
Since the TEST UNIT READY command is not part of the caller's command
issuing process, it is not covered by any external retry loops (such
as the main retry loop in sandev_command()).
We must therefore be prepared to retry the TEST UNIT READY command
within the SCSI layer itself. We retry only the TEST UNIT READY
command so as not to multiply the number of potential retries for
normal commands (which are already retried by sandev_command()).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[scsi] Avoid duplicate call to scsicmd_close() on TEST UNIT READY failure
When the TEST UNIT READY command receives an error response, the
shutdown of the command's block data interface will result in
scsidev_ready() closing the SCSI device. This will subsequently
result in a duplicate call to scsicmd_close(), leading to an assertion
failure when list_del() is called for the second time.
Fix by removing the command from the list of outstanding commands
before shutting down the command's interfaces.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When a SCSI device is closed in error, the shutdown of the device's
block data interface will probably lead to any outstanding commands
being closed (by whichever object is currently connected to the block
data interface). However, commands remain in the list of outstanding
commands until the final reference is dropped. The result is that
scsidev_close() will make a second call to scsicmd_close() for each
command. This is harmless, but produces confusing debug messages.
Fix by treating the outstanding command list as holding an explicit
reference to each command, and removing the command from the list of
outstanding commands in scsicmd_close().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The SCSI layer currently implements a retry loop in order to retry
commands that fail due to spurious "error" conditions such as "power
on occurred". Move this retry loop to the generic SAN device layer:
this allow for retries due to other transient error conditions such as
an iSCSI target having dropped the connection due to inactivity.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Parse the sense data to extract the reponse code, the sense key, the
additional sense code, and the additional sense code qualifier.
Originally-implemented-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[process] Pass containing object pointer to process step() methods
Give the step() method a pointer to the containing object, rather than
a pointer to the process. This is consistent with the operation of
interface methods, and allows a single function to serve as both an
interface method and a process step() method.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[scsi] Wait for a successful TEST UNIT READY command
Some SCSI targets (observed with an EMC CLARiiON Fibre Channel target)
will not respond to commands correctly until a TEST UNIT READY has
been issued. In particular, a READ CAPACITY (10) command will return
with a success status, but no capacity data.
Fix by issuing a TEST UNIT READY command automatically, and delaying
further SCSI commands until the TEST UNIT READY has succeeded.
Reported-by: Hadar Hen Zion <hadarh@mellanox.co.il>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[scsi] Include sense key within error number reported to user
The sense key gives a first idea of what the problem might be, and so
is potentially useful in diagnosing problems in a non-debug build.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[block] Replace gPXE block-device API with an iPXE asynchronous interface
The block device interface used in gPXE predates the invention of even
the old gPXE data-transfer interface, let alone the current iPXE
generic asynchronous interface mechanism. Bring this old code up to
date, with the following benefits:
o Block device commands can be cancelled by the requestor. The INT 13
layer uses this to provide a global timeout on all INT 13 calls,
with the result that an unexpected passive failure mode (such as
an iSCSI target ACKing the request but never sending a response)
will lead to a timeout that gets reported back to the INT 13 user,
rather than simply freezing the system.
o INT 13,00 (reset drive) is now able to reset the underlying block
device. INT 13 users, such as DOS, that use INT 13,00 as a method
for error recovery now have a chance of recovering.
o All block device commands are tagged, with a numerical tag that
will show up in debugging output and in packet captures; this will
allow easier interpretation of bug reports that include both
sources of information.
o The extremely ugly hacks used to generate the boot firmware tables
have been eradicated and replaced with a generic acpi_describe()
method (exploiting the ability of iPXE interfaces to pass through
methods to an underlying interface). The ACPI tables are now
built in a shared data block within .bss16, rather than each
requiring dedicated space in .data16.
o The architecture-independent concept of a SAN device has been
exposed to the iPXE core through the sanboot API, which provides
calls to hook, unhook, boot, and describe SAN devices. This
allows for much more flexible usage patterns (such as hooking an
empty SAN device and then running an OS installer via TFTP).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Access to the gpxe.org and etherboot.org domains and associated
resources has been revoked by the registrant of the domain. Work
around this problem by renaming project from gPXE to iPXE, and
updating URLs to match.
Also update README, LOG and COPYRIGHTS to remove obsolete information.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[scsi] Cope with targets that send multiple CHECK CONDITIONS at power-on
Some targets send a spurious CHECK CONDITION message in response to
the first SCSI command. We issue (and ignore the status of) an
arbitary harmless SCSI command (a READ CAPACITY (10)) in order to draw
out this response.
The Solaris Comstar target seems to send more than one spurious CHECK
CONDITION response. Attempt up to SCSI_MAX_DUMMY_READ_CAP dummy READ
CAPACITY (10) commands before assuming that error responses are
meaningful.
Problem reported by Kristof Van Doorsselaere <kvandoor@aserver.com>
and Shiva Shankar <802.11e@gmail.com>.
Add the concept of a "user pointer" (similar to the void __user * in
the kernel), which encapsulates the information needed to refer to an
external buffer. Under normal operation, this can just be a void *
equivalent, but under -DKEEP_IT_REAL it would be a segoff_t equivalent.
Use this concept to avoid the need for bounce buffers in int13.c,
which reduces memory usage and opens up the possibility of using
multi-sector reads.
Extend the block-device API and the SCSI block device implementation
to support multi-sector reads.
Update iscsi.c to use user buffers.
Move the obsolete portions of realmode.h to old_realmode.h.
MS-DOS now boots an order of magnitude faster over iSCSI (~10 seconds
from power-up to C:> prompt in bochs).
Michael Brown