summaryrefslogtreecommitdiff
path: root/drivers/ieee1394/nodemgr.c
AgeCommit message (Collapse)AuthorFilesLines
2009-03-24ieee1394: constify device ID tablesStefan Richter1-2/+2
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2009-02-24ieee1394: inherit ud vendor_id from node vendor_idStefan Richter1-0/+3
While Module_Vendor_ID in the configuration ROM's root directory is mandatory, there often aren't vendor IDs in unit directories. This affects the new firedtv driver which is meant to be auto-loaded and matched only for vendor-specific devices. We now always copy ne->vendor_id into ud->vendor_id before we scan a unit directory (and fill in a possibly present vendor ID from there). This way, the root directory's vendor ID is used as fallback in the "uevent" environment for modprobe'ing per module alias when a node was plugged in, and in the driver match routine when protocol drivers are bound to unit directories. It will however not be used as sysfs attribute of a unit directory device. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2009-02-24ieee1394: use correct barrier types between accesses of nodeid and generationStefan Richter1-3/+4
A compiler barrier (explicit on the read side, implicit on the write side) is not quite enough for what has to be accomplished here. Use hardware memory barriers on systems which need them. (Of course a full fix of generation handling would require much more than this. The ieee1394 core's bus generation counter had to be tied to the controller's bus generation counter; cf. Kristian's stack. It's just that I have other current business with the code around these barrier()s, so why not do at least this small fix.) Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2009-01-04ieee1394: ignore nonzero Bus_Info_Block.max_rom, fetch config ROM in quadletsStefan Richter1-16/+4
It is already known that buggy firmwares exist which report a bogus link_spd in their config ROM bus info block. We now got the first report of a bogus max_rom too (Freecom FireWire Hard Drive 1TB, http://bugzilla.kernel.org/show_bug.cgi?id=12206). I suspect other OSs only use quadlet reads to fetch the config ROM, otherwise the firmware authors would have noticed their mistake. Hence limit ieee1394's config ROM fetching routine to quadlets as the safe minimum regardless of what the bus info block says. This will potentially slow the bus reset handling by nodemgr somewhat down. But most existing devices support only quadlet reads anyway, hence there will often be no actual difference to before this change. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-12-14ieee1394: add quirk fix for Freecom HDDStefan Richter1-0/+6
According to http://bugzilla.kernel.org/show_bug.cgi?id=12206, Freecom FireWire Hard Drive 1TB reports max_rom=2 but returns garbage if block read requests are used to read the config ROM. Force max_rom=0 to limit them to quadlet read requests. Reported-by: Christian Mueller <cm1@mumac.de> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-12-09ieee1394: node manager causes up to ~3.25s delay in freezing tasksNigel Cunningham1-0/+2
The firewire nodemanager function "nodemgr_host_thread" contains a loop that calls try_to_freeze near the top of the loop, but then delays for up to 3.25 seconds (plus time to do work) before getting back to the top of the loop. When starting a cycle post-boot, this doesn't seem to bite, but it is causing a noticeable delay at boot time, when freezing processes prior to starting to read the image. The following patch adds invocation of try_to_freeze to the subloops that are used in the body of this function. With these additions, the time to freeze when starting to resume at boot time is virtually zero. I'm no expert on firewire, and so don't know that we shouldn't check the return value and jump back to the top of the loop or such like after being frozen, but I submit it for your consideration. Signed-off-by: Nigel Cunningham <nigel@tuxonice.net> The delay until nodemgr freezes was up to 0.25s (plus time for node probes) in Linux 2.6.27 and older and up to 3.25s (plus ~) since Linux 2.6.28-rc1, hence much more noticeable. try_to_freeze() without any jump is correct. The surrounding code in the respective loops will catch whether another bus reset happens during the freeze and handle it. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-10-31ieee1394: struct device - replace bus_id with dev_name(), dev_set_name()Kay Sievers1-9/+5
Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-10-15ieee1394: survive a few seconds connection lossStefan Richter1-97/+50
There are situations when nodes vanish from the bus and come back in quickly thereafter: - When certain bus-powered hubs are plugged in, - when certain disk enclosures are switched from self-power to bus power or vice versa and break the daisy chain during the transition, - when the user plugs a cable out and quickly plugs it back in, e.g. to reorder a daisy chain (works on Mac OS X if done quickly enough), - when certain hubs temporarily malfunction during high bus traffic. The ieee1394 driver's nodemgr already contained a function to set vanished nodes aside into "limbo"; i.e. they wouldn't actually be deleted right away. (In fact, only unloading the driver or writing into an obscure sysfs attribute would delete them eventually.) If nodes reappeared later, they would be resurrected out of limbo. Moving nodes into and out of limbo was accompanied with calling the .suspend() and .resume() driver methods of the drivers which were bound to a respective node's unit directories. Not only is this somewhat strange due to the intended use of these driver methods for power management, also the sbp2 driver in particular does not implement .suspend() and .resume(). Hence sbp2 would be disconnected from devices in situations as listed above. We now: - leave drivers bound when nodes go into limbo, - call the drivers' .update() when nodes come out of limbo, - automatically delete in-limbo nodes 3 seconds after the last bus reset and bus rescan. - Because of the automatic removal, the now obsolete bus attribute /sys/bus/ieee1394/destroy_node is removed. This especially lets sbp2 survive brief disconnections. You can for example yank a disk's cable and plug it back in while reading the respective disk with dd, but dd will happily continue as if nothing happened. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-10-15ieee1394: nodemgr clean up class iteratorsStefan Richter1-97/+81
Remove useless pointer type casts. Remove unnecessary hi->host indirection where only host is used. Remove an unnecessary WARN_ON. Change a few names. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-08-19ieee1394: don't drop nodes during bus reset seriesStefan Richter1-19/+21
nodemgr_node_probe checked for generation increments too late and therefore prematurely reported nodes as "suspended". Fixes http://bugzilla.kernel.org/show_bug.cgi?id=11349. Reported and tested by Damien Benoist. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-08-19ieee1394: regression in 2.6.25: updates should happen before probesStefan Richter1-14/+15
Regression since commit 73cf60232ef16e1f8a64defa97214a1722db1e6c, "ieee1394: use class iteration api": The two loops for (1.) driver updates and (2.) driver probes were replaced by a single loop with bogus needs_probe checks. Hence updates and probes were now intermixed, and especially sbp2 updates (reconnects) held up longer than necessary. While we fix it, change the needs_probe flag to bool type for clarity. Tested by Damien Benoist. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-07-21Driver Core: add ability for class_find_device to start in middle of listGreg Kroah-Hartman1-3/+6
This mirrors the functionality that driver_find_device has as well. We add a start variable, and all callers of the function are fixed up at the same time. The block layer will be using this new functionality in a follow-on patch. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-21Driver Core: add ability for class_for_each_device to start in middle of listGreg Kroah-Hartman1-5/+9
This mirrors the functionality that driver_for_each_device has as well. We add a start variable, and all callers of the function are fixed up at the same time. The block layer will be using this new functionality in a follow-on patch. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-05-01Merge branch 'for-linus' of ↵Linus Torvalds1-1/+4
git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6: firewire: fw-sbp2: log scsi_target ID at release ieee1394: fix NULL pointer dereference in sysfs access
2008-05-01ieee1394: fix NULL pointer dereference in sysfs accessStefan Richter1-1/+4
Regression since "ieee1394: prevent device binding of raw1394, video1394, dv1394", commit d2ace29fa44589da51fedc06a67b3f05301f3bfd: $ cat /sys/bus/ieee1394/drivers/raw1394/device_ids triggers a NULL pointer dereference in fw_show_drv_device_ids. Reported by Miles Lane. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Tested-by: Miles Lane <miles.lane@gmail.com>
2008-04-18Convert asm/semaphore.h users to linux/semaphore.hMatthew Wilcox1-1/+1
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2008-04-18ieee1394: prevent device binding of raw1394, video1394, dv1394Stefan Richter1-1/+5
These drivers don't need to match any unit_directory type device. They just need the id_table for module autoloading per module alias. Not binding any of these drivers allows special-purpose drivers with similar or same IDs to bind to devices. This currently only benefits out-of-tree drivers; on the other hand it is in no way detrimental to in-tree drivers. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-01-24ieee1394: use class iteration apiDave Young1-138/+176
Convert to use the class iteration api. Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-16ieee1394: csr1212: proper refcountingStefan Richter1-2/+2
At least since nodemgr got rid of coarse global locking, accesses to struct csr1212_keyval's reference counter should be atomic and coupled with proper barriers. Also, calls to csr1212_keep_keyval(kv) should occur before kv is being used. (We probably should convert refcnt to struct kref, but how to keep csr1212_destroy_keyval's implementation non-recursively then?) Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-10-16ieee1394: nodemgr: fix leak of struct csr1212_keyvalStefan Richter1-6/+9
csr1212_keep_keyval(kv) in nodemgr_process_root_directory was unbalanced if ne->vendor_name_kv already exists. This happens for example if eth1394 or raw1394 modify the local config ROM and it is parsed again. As a bonus, the attempt to add the vendor_name_kv sysfs attribute when it already exists is now fixed for good. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-10-16ieee1394: Fix kthread stopping in nodemgr_host_threadSatyam Sharma1-1/+2
The nodemgr host thread can exit on its own even when kthread_should_stop is not true, on receiving a signal (might never happen in practice, as it ignores signals). But considering kthread_stop() must not be mixed with kthreads that can exit on their own, I think changing the code like this is clearer. This change means the thread can cut its sleep short when receive a signal but looking at the code around, that sounds okay (and again, it might never actually recieve a signal in practice). Signed-off-by: Satyam Sharma <satyam@infradead.org> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-10-12Driver core: change add_uevent_var to use a structKay Sievers1-13/+4
This changes the uevent buffer functions to use a struct instead of a long list of parameters. It does no longer require the caller to do the proper buffer termination and size accounting, which is currently wrong in some places. It fixes a known bug where parts of the uevent environment are overwritten because of wrong index calculations. Many thanks to Mathieu Desnoyers for finding bugs and improving the error handling. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-17Freezer: make kernel threads nonfreezable by defaultRafael J. Wysocki1-0/+1
Currently, the freezer treats all tasks as freezable, except for the kernel threads that explicitly set the PF_NOFREEZE flag for themselves. This approach is problematic, since it requires every kernel thread to either set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't care for the freezing of tasks at all. It seems better to only require the kernel threads that want to or need to be frozen to use some freezer-related code and to remove any freezer-related code from the other (nonfreezable) kernel threads, which is done in this patch. The patch causes all kernel threads to be nonfreezable by default (ie. to have PF_NOFREEZE set by default) and introduces the set_freezable() function that should be called by the freezable kernel threads in order to unset PF_NOFREEZE. It also makes all of the currently freezable kernel threads call set_freezable(), so it shouldn't cause any (intentional) change of behaviour to appear. Additionally, it updates documentation to describe the freezing of tasks more accurately. [akpm@linux-foundation.org: build fixes] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Nigel Cunningham <nigel@nigel.suspend2.net> Cc: Pavel Machek <pavel@ucw.cz> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-15ieee1394: forgotten dereference...Al Viro1-1/+1
Going through the string and waiting for _pointer_ to become '\0' is not what the authors meant... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Ben Collins <ben.collins@ubuntu.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-10ieee1394: nodemgr: parallelize between several hostsStefan Richter1-26/+43
Remove the global nodemgr_serialize mutex which enclosed most of the host thread event loop. This allows for parallelism between several host adapter cards. Properly serialize the driver hooks .update(), .suspend(), .resume(), and .remove() by means of device->sem. These hooks can be called from outside the host threads' contexts. Get() and put() the device.driver when calling its hooks. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-07-10ieee1394: convert ieee1394 from "struct class_device" to "struct device"Kay Sievers1-58/+60
Here is a straightforward conversion to "struct device". The "struct class_device" will be removed from the kernel. It seems to work fine for me with and without CONFIG_SYSFS_DEPRECATED set. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-05-31ieee1394: sbp2: offer SAM-conforming target port ID in sysfsStefan Richter1-0/+5
With "modprobe sbp2 long_ieee1394_id=y", the format of /sys/bus/scsi/devices/*:*:*:*/ieee1394_id is changed from e.g. 0001041010004beb:0:0 to 0001041010004beb:00042c:0000. The longer format fully conforms to object identifier sizes as per SAM(-2...4) and reflects what the SAM target port identifier is meant to contain: A Discovery ID allegedly specified by ISO/IEC 13213:1994 --- however there is no such thing; the authors of SAM probably meant Directory ID). Especially target nodes with multiple dynamically added targets may use Directory IDs to persistently identify target ports. The new format is independent of implementation details of nodemgr. Thus the same ieee1394_id attribute format can be implemented in the new firewire stack. The ieee1394_id is typically used to create persistently named links in /dev/disk/by-id. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-05-31ieee1394: fix calculation of sysfs attribute "address"Stefan Richter1-1/+1
struct csr1212_keyval.offset is relative to 0xffff f000 0000 rather than 0xffff f000 0400. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-05-09Fix occurrences of "the the "Michael Opdenacker1-1/+1
Signed-off-by: Michael Opdenacker <michael@free-electrons.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2007-04-30ieee1394: nodemgr: unify some error messagesStefan Richter1-8/+5
Shrinks object file size a little bit. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-04-30ieee1394: nodemgr: less noise in dmesgStefan Richter1-7/+8
Everytime when eth1394 or a libraw1394 client updates the configuration ROM, a certain sysfs attribute cannot be added since it already exists. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-04-30ieee1394: some more includesStefan Richter1-0/+1
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-04-30ieee1394: drop csr1212's support for external compilationStefan Richter1-1/+1
csr1212 was written to be compiled either as part of the ieee1394 kernel driver or of an anticipated IEEE 1212 userspace library. We now drop support for the latter. The costs in terms of code footprint and depth of abstraction are not countered by any actual benefit. Also remove some obsolete #includes. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-04-30ieee1394: move some comments from declaration to definitionStefan Richter1-6/+26
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-04-30ieee1394: remove declarations of nonexisting functionsStefan Richter1-1/+1
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-04-27IEEE1394: remove rwsem use from ieee1394 coreGreg Kroah-Hartman1-8/+0
The subsystem rwsem is not used by the driver core at all, so the use of it in the ieee1394 code doesn't make any sense. They might possibly want to use a local lock, but as most of these operations are already protected by a local lock, it really doesn't look like it would be needed. Cc: Ben Collins <bcollins@debian.org> Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: linux1394-devel <linux1394-devel@lists.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-04-27uevent: use add_uevent_var() instead of open coding itEric Rannaud1-8/+6
Make use of add_uevent_var() instead of (often incorrectly) open coding it. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Eric Rannaud <eric.rannaud@gmail.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-17ieee1394: fix another deadlock in nodemgrStefan Richter1-1/+2
A "modprobe ohci1394; sleep 1.5; modprobe -r ohci1394" could get stuck in uninterruptible state, especially if an external node was connected. http://bugzilla.kernel.org/show_bug.cgi?id=7792 Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-02-08ieee1394: fix host device registering when nodemgr disabledStefan Richter1-8/+16
Since my commit 8252bbb1363b7fe963a3eb6f8a36da619a6f5a65 in 2.6.20-rc1, host devices have a dummy driver attached. Alas the driver was not registered before use if ieee1394 was loaded with disable_nodemgr=1. This resulted in non-functional FireWire drivers or kernel lockup. http://bugzilla.kernel.org/show_bug.cgi?id=7942 Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-02-08the scheduled IEEE1394_OUI_DB removalAdrian Bunk1-39/+0
This patch contains the scheduled IEEE1394_OUI_DB removal. Signed-off-by: Adrian Bunk <bunk@stusta.de> Update: Also remove drivers/ieee1394/.gitignore. Remove now unused struct members in drivers/ieee1394/nodemgr.h. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2006-12-07ieee1394: nodemgr: remove a kcallocStefan Richter1-46/+20
Was I sleepwalking when I wrote this? Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2006-12-07ieee1394: Consolidate driver registeringBen Collins1-3/+10
This patch consolidates some bookkeeping for driver registering. It closely models what pci_register_driver() does. The main addition is that the owner of the driver is set, so we get a proper symlink for /sys/bus/ieee1394/driver/*/module. Also moves setting of name and bus type into nodemgr. Because of this, we can remove the EXPORT_SYMBOL for ieee1394_bus_type, since it's now only used in ieee1394.ko. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2006-12-07ieee1394: nodemgr: spaces to tabsStefan Richter1-49/+49
whitespace pedantry Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2006-12-07ieee1394: nodemgr: fix deadlock in shutdownStefan Richter1-3/+18
If "modprobe ohci1394" was quickly followed by "modprobe -r ohci1394", say with 1 second pause in between, the modprobe -r got stuck in uninterruptible sleep in kthread_stop. At the same time the knodemgrd slept uninterruptibly in bus_rescan_devices_helper. That's because driver_detach took the semaphore of the PCI device and bus_rescan_devices_helper wanted to take the semaphore of the FireWire host device's parent, which is the same semaphore. This was a regression since Linux 2.6.16, commit bf74ad5bc41727d5f2f1c6bedb2c1fac394de731, "Hold the device's parent's lock during probe and remove". The fix (or workaround) adds a dummy driver to the hpsb_host device. Now bus_rescan_devices_helper won't scan the host device anymore. This doesn't hurt since we have no drivers which will bind to these devices and it is unlikely that there will ever be such a driver. The dummy driver is befittingly presented as a representation of ieee1394 itself. Fixes: http://bugzilla.kernel.org/show_bug.cgi?id=6706 Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2006-12-07ieee1394: nodemgr: remove duplicate assignmentStefan Richter1-1/+1
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2006-12-07ieee1394: nodemgr: take it easy if bus_rescan_devices failsStefan Richter1-3/+2
This happens. No need to log a BUG trace. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2006-12-07drivers/ieee1394/*: use kmemdup()Eric Sesterhenn1-2/+1
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2006-12-07ieee1394: fix printk format warningRandy Dunlap1-1/+1
Fix printk format warning: drivers/ieee1394/nodemgr.c:364: warning: long long unsigned int format, u64 arg (arg 3) Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2006-12-07ieee1394: nodemgr: revise semaphore protection of driver core dataStefan Richter1-50/+92
- The list "struct class.children" is supposed to be protected by class.sem, not by class.subsys.rwsem. - nodemgr_remove_uds() iterated over nodemgr_ud_class.children without proper protection. This was never observed as a bug since the code is usually only accessed by knodemgrd. All knodemgrds are currently globally serialized. But userspace can trigger this code too by writing to /sys/bus/ieee1394/destroy_node. - Clean up access to the FireWire bus type's subsys.rwsem: Access it uniformly via ieee1394_bus_type. Shrink rwsem protected regions where possible. Expand them where necessary. The latter wasn't a problem so far because knodemgr is globally serialized. This should harden the interaction of ieee1394 with sysfs and lay ground for deserialized operation of multiple knodemgrds and for implementation of subthreads for parallelized scanning and probing. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2006-12-07ieee1394: nodemgr: reflect which return values are errorsStefan Richter1-34/+30
Give better names to local variables. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>