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path: root/drivers/block/aoe
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2009-12-01aoe: prevent cache aliasesPeter Horton
Prevent the AoE block driver from creating cache aliases of page cache pages on machines with virtually indexed caches. Building kernels on an AT91SAM9G20 board without this patch fails with segmentation faults after a couple of passes. Signed-off-by: Peter Horton <zero@colonel-panic.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22const: make block_device_operations constAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-19Driver-Core: extend devnode callbacks to provide permissionsKay Sievers
This allows subsytems to provide devtmpfs with non-default permissions for the device node. Instead of the default mode of 0600, null, zero, random, urandom, full, tty, ptmx now have a mode of 0666, which allows non-privileged processes to access standard device nodes in case no other userspace process applies the expected permissions. This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-14Merge branch 'for-2.6.32' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.32' of git://git.kernel.dk/linux-2.6-block: (29 commits) block: use blkdev_issue_discard in blk_ioctl_discard Make DISCARD_BARRIER and DISCARD_NOBARRIER writes instead of reads block: don't assume device has a request list backing in nr_requests store block: Optimal I/O limit wrapper cfq: choose a new next_req when a request is dispatched Seperate read and write statistics of in_flight requests aoe: end barrier bios with EOPNOTSUPP block: trace bio queueing trial only when it occurs block: enable rq CPU completion affinity by default cfq: fix the log message after dispatched a request block: use printk_once cciss: memory leak in cciss_init_one() splice: update mtime and atime on files block: make blk_iopoll_prep_sched() follow normal 0/1 return convention cfq-iosched: get rid of must_alloc flag block: use interrupts disabled version of raise_softirq_irqoff() block: fix comment in blk-iopoll.c block: adjust default budget for blk-iopoll block: fix long lines in block/blk-iopoll.c block: add blk-iopoll, a NAPI like approach for block devices ...
2009-09-14aoe: end barrier bios with EOPNOTSUPPEd Cashin
BugLink: http://bugzilla.kernel.org/show_bug.cgi?id=13942 Bruno Premont noticed that aoe throws a BUG during umount of an XFS in 2.6.31: [ 5259.349897] aoe: bi_io_vec is NULL [ 5259.349940] ------------[ cut here ]------------ [ 5259.349958] kernel BUG at /usr/src/linux-2.6/drivers/block/aoe/aoeblk.c:177! [ 5259.349990] invalid opcode: 0000 [#1] The bio in question is a barrier. Jens Axboe suggested that such bios need to be recognized and ended with -EOPNOTSUPP by any driver that provides its own ->make_request_fn handler and does not handle barriers. In testing the changes below eliminate the BUG. (Better would be real barrier support, something that Ed says he'll add for later in the .32 cycle. For now, this at least gets rid of a bug with crashing on an empty barrier. Jens) Signed-off-by: Ed L. Cashin <ecashin@coraid.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11writeback: add name to backing_dev_infoJens Axboe
This enables us to track who does what and print info. Its main use is catching dirty inodes on the default_backing_dev_info, so we can fix that up. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-09aoe: allocate unused request_queue for sysfsEd Cashin
Andy Whitcroft reported an oops in aoe triggered by use of an incorrectly initialised request_queue object: [ 2645.959090] kobject '<NULL>' (ffff880059ca22c0): tried to add an uninitialized object, something is seriously wrong. [ 2645.959104] Pid: 6, comm: events/0 Not tainted 2.6.31-5-generic #24-Ubuntu [ 2645.959107] Call Trace: [ 2645.959139] [<ffffffff8126ca2f>] kobject_add+0x5f/0x70 [ 2645.959151] [<ffffffff8125b4ab>] blk_register_queue+0x8b/0xf0 [ 2645.959155] [<ffffffff8126043f>] add_disk+0x8f/0x160 [ 2645.959161] [<ffffffffa01673c4>] aoeblk_gdalloc+0x164/0x1c0 [aoe] The request queue of an aoe device is not used but can be allocated in code that does not sleep. Bruno bisected this regression down to cd43e26f071524647e660706b784ebcbefbd2e44 block: Expose stacked device queues in sysfs "This seems to generate /sys/block/$device/queue and its contents for everyone who is using queues, not just for those queues that have a non-NULL queue->request_fn." Addresses http://bugs.launchpad.net/bugs/410198 Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13942 Note that embedding a queue inside another object has always been an illegal construct, since the queues are reference counted and must persist until the last reference is dropped. So aoe was always buggy in this respect (Jens). Signed-off-by: Ed Cashin <ecashin@coraid.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Bruno Premont <bonbons@linux-vserver.org> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-06-15Driver Core: aoe: add nodename for aoe devicesKay Sievers
This adds support to the AOE core to report the proper device name to userspace for the AOE devices. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-05-27aoe: Remove superfluous clearing of skb fields in new_skb().David S. Miller
This code uses alloc_skb() which clears them out for us. Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-01aoe: WIN_* -> ATA_CMD_*Bartlomiej Zolnierkiewicz
* Use ATA_CMD_* defines instead of WIN_* ones. * Include <linux/ata.h> directly instead of through <linux/hdreg.h>. Cc: Ed L. Cashin <ecashin@coraid.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2009-03-10net: convert usage of packet_type to read_mostlyStephen Hemminger
Protocols that use packet_type can be __read_mostly section for better locality. Elminate any unnecessary initializations of NULL. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-04aoe: error printed 1 too earlyRoel Kluin
with while (i-- > 0); i reaches -1 after the loop, so the test below is printed one too early: 0 still means success. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-18aoe: ignore vendor extension AoE responsesEd Cashin
The Welland ME-747K-SI AoE target generates unsolicited AoE responses that are marked as vendor extensions. Instead of ignoring these packets, the aoe driver was generating kernel messages for each unrecognized response received. This patch corrects the behavior. Signed-off-by: Ed Cashin <ecashin@coraid.com> Reported-by: <karaluh@karaluh.pl> Tested-by: <karaluh@karaluh.pl> Cc: <stable@kernel.org> Cc: Alex Buell <alex.buell@munted.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-25aoe: remove private mac address format functionHarvey Harrison
Add %pm to omit the colons when printing a mac address. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-21[PATCH] switch aoeblkAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-21[PATCH] beginning of methods conversionAl Viro
To keep the size of changesets sane we split the switch by drivers; to keep the damn thing bisectable we do the following: 1) rename the affected methods, add ones with correct prototypes, make (few) callers handle both. That's this changeset. 2) for each driver convert to new methods. *ALL* drivers are converted in this series. 3) kill the old (renamed) methods. Note that it _is_ a flagday; all in-tree drivers are converted and by the end of this series no trace of old methods remain. The only reason why we do that this way is to keep the damn thing bisectable and allow per-driver debugging if anything goes wrong. New methods: open(bdev, mode) release(disk, mode) ioctl(bdev, mode, cmd, arg) /* Called without BKL */ compat_ioctl(bdev, mode, cmd, arg) locked_ioctl(bdev, mode, cmd, arg) /* Called with BKL, legacy */ Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-20x86: sysfs: kill owner field from attributeParag Warudkar
Tejun's commit 7b595756ec1f49e0049a9e01a1298d53a7faaa15 made sysfs attribute->owner unnecessary. But the field was left in the structure to ease the merge. It's been over a year since that change and it is now time to start killing attribute->owner along with its users - one arch at a time! This patch is attempt #1 to get rid of attribute->owner only for CONFIG_X86_64 or CONFIG_X86_32 . We will deal with other arches later on as and when possible - avr32 will be the next since that is something I can test. Compile (make allyesconfig / make allmodconfig / custom config) and boot tested. akpm: the idea is that we put the declaration of sttribute.owner inside `#ifndef CONFIG_X86'. But that proved to be too ambitious for now because new usages kept on turning up in subsystem trees. [akpm: remove the ifdef for now] Signed-off-by: Parag Warudkar <parag.lkml@gmail.com> Cc: Greg KH <greg@kroah.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Tejun Heo <htejun@gmail.com> Cc: Len Brown <lenb@kernel.org> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Jean Delvare <khali@linux-fr.org> Cc: Roland Dreier <rolandd@cisco.com> Cc: David Brownell <david-b@pacbell.net> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16device create: block: convert device_create_drvdata to device_createGreg Kroah-Hartman
Now that device_create() has been audited, rename things back to the original call to be sane. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1075 commits) myri10ge: update driver version number to 1.4.3-1.369 r8169: add shutdown handler r8169: preliminary 8168d support r8169: support additional 8168cp chipset r8169: change default behavior for mildly identified 8168c chipsets r8169: add a new 8168cp flavor r8169: add a new 8168c flavor (bis) r8169: add a new 8168c flavor r8169: sync existing 8168 device hardware start sequences with vendor driver r8169: 8168b Tx performance tweak r8169: make room for more specific 8168 hardware start procedure r8169: shuffle some registers handling around (8168 operation only) r8169: new phy init parameters for the 8168b r8169: update phy init parameters r8169: wake up the PHY of the 8168 af_key: fix SADB_X_SPDDELETE response ath9k: Fix return code when ath9k_hw_setpower() fails on reset ath9k: remove nasty FAIL macro from ath9k_hw_reset() gre: minor cleanups in netlink interface gre: fix copy and paste error ...
2008-10-09block: move stats from disk to part0Tejun Heo
Move stats related fields - stamp, in_flight, dkstats - from disk to part0 and unify stat handling such that... * part_stat_*() now updates part0 together if the specified partition is not part0. ie. part_stat_*() are now essentially all_stat_*(). * {disk|all}_stat_*() are gone. * part_round_stats() is updated similary. It handles part0 stats automatically and disk_round_stats() is killed. * part_{inc|dec}_in_fligh() is implemented which automatically updates part0 stats for parts other than part0. * disk_map_sector_rcu() is updated to return part0 if no part matches. Combined with the above changes, this makes NULL special case handling in callers unnecessary. * Separate stats show code paths for disk are collapsed into part stats show code paths. * Rename disk_stat_lock/unlock() to part_stat_lock/unlock() While at it, reposition stat handling macros a bit and add missing parentheses around macro parameters. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-09block: move capacity from disk to part0Tejun Heo
Move disk->capacity to part0->nr_sects and convert all users who directly accessed the field to use {get|set}_capacity(). This is done early to allow the __dev field to be moved. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-09block: implement and use {disk|part}_to_dev()Tejun Heo
Implement {disk|part}_to_dev() and use them to access generic device instead of directly dereferencing {disk|part}->dev. To make sure no user is left behind, rename generic devices fields to __dev. This is in preparation of unifying partition 0 handling with other partitions. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-09block: fix diskstats accessTejun Heo
There are two variants of stat functions - ones prefixed with double underbars which don't care about preemption and ones without which disable preemption before manipulating per-cpu counters. It's unclear whether the underbarred ones assume that preemtion is disabled on entry as some callers don't do that. This patch unifies diskstats access by implementing disk_stat_lock() and disk_stat_unlock() which take care of both RCU (for partition access) and preemption (for per-cpu counter access). diskstats access should always be enclosed between the two functions. As such, there's no need for the versions which disables preemption. They're removed and double underbars ones are renamed to drop the underbars. As an extra argument is added, there's no danger of using the old version unconverted. disk_stat_lock() uses get_cpu() and returns the cpu index and all diskstat functions which access per-cpu counters now has @cpu argument to help RT. This change adds RCU or preemption operations at some places but also collapses several preemption ops into one at others. Overall, the performance difference should be negligible as all involved ops are very lightweight per-cpu ones. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-09block: fix disk->part[] dereferencing raceTejun Heo
disk->part[] is protected by its matching bdev's lock. However, non-critical accesses like collecting stats and printing out sysfs and proc information used to be performed without any locking. As partitions can come and go dynamically, partitions can go away underneath those non-critical accesses. As some of those accesses are writes, this theoretically can lead to silent corruption. This patch fixes the race by using RCU for the partition array and dev reference counter to hold partitions. * Rename disk->part[] to disk->__part[] to make sure no one outside genhd layer proper accesses it directly. * Use RCU for disk->__part[] dereferencing. * Implement disk_{get|put}_part() which can be used to get and put partitions from gendisk respectively. * Iterators are implemented to help iterate through all partitions safely. * Functions which require RCU readlock are marked with _rcu suffix. * Use disk_put_part() in __blkdev_put() instead of directly putting the contained kobject. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-09block: misc updatesTejun Heo
This patch makes the following misc updates in preparation for disk->part dereference fix and extended block devt support. * implment part_to_disk() * fix comment about gendisk->part indexing * rename get_part() to disk_map_sector() * don't use n which is always zero while printing disk information in diskstats_show() Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-09-23aoe: Fix OOPS after SKB queue changes.David S. Miller
Reported by Thomas Graf. If we don't unlink the SKB from the queue when we send it out in aoenet_xmit(), dev_hard_start_xmit() will see skb->next as non-NULL and interpret this to mean the SKB is part of a GSO segment list. Add __skb_unlink() call to fix that. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-09-21aoe: Use SKB interfaces for list management instead of home-grown stuff.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-01Remove newline from the description of module parametersNiels de Vos
Some module parameters with only one line have the '\n' at the end of the description. This is not needed nor wanted as after the description the type (i.e. int) is followed by a newline. Some modules contain a multi-line description, these are not affected by this patch. Signed-off-by: Niels de Vos <niels.devos@wincor-nixdorf.com> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: John W. Linville <linville@tuxdriver.com> Cc: Ed L. Cashin <ecashin@coraid.com> Cc: Dave Airlie <airlied@linux.ie> Cc: Roland Dreier <rolandd@cisco.com> Acked-by: Mauro Carvalho Chehab <mchehab@infradead.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25aoe: convert emsgs_sema into a completionMatthias Kaehlcke
ATA over Ethernet: The semaphore emsgs_sema is used for signalling an event, convert it in a completion. Signed-off-by: Matthias Kaehlcke <matthias@kaehlcke.net> Cc: "Ed L. Cashin" <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-21device create: block: convert device_create to device_create_drvdataGreg Kroah-Hartman
device_create() is race-prone, so use the race-free device_create_drvdata() instead as device_create() is going away. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-14Merge branch 'bkl-removal' of git://git.lwn.net/linux-2.6Linus Torvalds
* 'bkl-removal' of git://git.lwn.net/linux-2.6: (146 commits) IB/umad: BKL is not needed for ib_umad_open() IB/uverbs: BKL is not needed for ib_uverbs_open() bf561-coreb: BKL unneeded for open() Call fasync() functions without the BKL snd/PCM: fasync BKL pushdown ipmi: fasync BKL pushdown ecryptfs: fasync BKL pushdown Bluetooth VHCI: fasync BKL pushdown tty_io: fasync BKL pushdown tun: fasync BKL pushdown i2o: fasync BKL pushdown mpt: fasync BKL pushdown Remove BKL from remote_llseek v2 Make FAT users happier by not deadlocking x86-mce: BKL pushdown vmwatchdog: BKL pushdown vmcp: BKL pushdown via-pmu: BKL pushdown uml-random: BKL pushdown uml-mmapper: BKL pushdown ...
2008-07-04block: use get_unaligned_* helpersHarvey Harrison
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-06-20AoE: cdev lock_kernel() pushdownJonathan Corbet
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2008-05-07block: avoid duplicate calls to get_part() in disk stat codeJens Axboe
get_part() is fairly expensive, as it O(N) loops over partitions to find the right one. In lots of normal IO paths we end up looking up the partition twice, to make matters even worse. Change the stat add code to accept a passed in partition instead. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-04-29drivers/block: use get_unaligned_* helpersHarvey Harrison
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Cc: Ed L. Cashin <ecashin@coraid.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29remove aoedev_isbusy()Adrian Bunk
Remove the no longer used aoedev_isbusy(). Signed-off-by: Adrian Bunk <bunk@kernel.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-26[NET] NETNS: Omit net_device->nd_net without CONFIG_NET_NS.YOSHIFUJI Hideaki
Introduce per-net_device inlines: dev_net(), dev_net_set(). Without CONFIG_NET_NS, no namespace other than &init_net exists. Let's explicitly define them to help compiler optimizations. Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
2008-02-08Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: Enhanced partition statistics: documentation update Enhanced partition statistics: remove old partition statistics Enhanced partition statistics: procfs Enhanced partition statistics: sysfs Enhanced partition statistics: aoe fix Enhanced partition statistics: update partition statitics Enhanced partition statistics: core statistics block: fixup rq_init() a bit Manually fixed conflict in drivers/block/aoe/aoecmd.c due to statistics support.
2008-02-08aoe: statically initialise devlist_lockAndrew Morton
I guess aoedev_init() can go away now. Cc: Greg KH <greg@kroah.com> Cc: "Ed L. Cashin" <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08aoe: update copyright dateEd L. Cashin
Update the year in the copyright notices. Signed-off-by: Ed L. Cashin <ecashin@coraid.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08aoe: make error messages more specificEd L. Cashin
Andrew Morton pointed out that the "too many targets" message in patch 2 could be printed for failing GFP_ATOMIC allocations. This patch makes the messages more specific. Signed-off-by: Ed L. Cashin <ecashin@coraid.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08aoe: the aoeminor doesn't need a long formatEd L. Cashin
The aoedev aoeminor member doesn't need a long format. Signed-off-by: Ed L. Cashin <ecashin@coraid.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08aoe: add module parameter for users who need more outstanding I/OEd L. Cashin
An AoE target provides an estimate of the number of outstanding commands that the AoE initiator can send before getting a response. The aoe_maxout parameter provides a way to set an even lower limit. It will not allow a user to use more outstanding commands than the target permits. If a user discovers a problem with a large setting, this parameter provides a way for us to work with them to debug the problem. We expect to improve the dynamic window sizing algorithm and drop this parameter. For the time being, it is a debugging aid. Signed-off-by: Ed L. Cashin <ecashin@coraid.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08aoe: only install new AoE device onceEd L. Cashin
An aoe driver user who had about 70 AoE targets found that he was hitting a BUG in sysfs_create_file because the aoe driver was trying to tell the kernel about an AoE device more than once. Each AoE device was reachable by several local network interfaces, and multiple ATA device indentify responses were returning from that single device. This patch eliminates a race condition so that aoe always informs the block layer of a new AoE device once in the presence of multiple incoming ATA device identify responses. Signed-off-by: Ed L. Cashin <ecashin@coraid.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08aoe: dynamically allocate a capped number of skbs when necessaryEd L. Cashin
What this Patch Does Even before this recent series of 12 patches to 2.6.22-rc4, the aoe driver was reusing a small set of skbs that were allocated once and were only used for outbound AoE commands. The network layer cannot be allowed to put_page on the data that is still associated with a bio we haven't returned to the block layer, so the aoe driver (even before the patch under discussion) is still the owner of skbs that have been handed to the network layer for transmission. We need to keep track of these skbs so that we can free them, but by tracking them, we can also easily re-use them. The new patch was a response to the behavior of certain network drivers. We cannot reuse an skb that the network driver still has in its transmit ring. Network drivers can defer transmit ring cleanup and then use the state in the skb to determine how many data segments to clean up in its transmit ring. The tg3 driver is one driver that behaves in this way. When the network driver defers cleanup of its transmit ring, the aoe driver can find itself in a situation where it would like to send an AoE command, and the AoE target is ready for more work, but the network driver still has all of the pre-allocated skbs. In that case, the new patch just calls alloc_skb, as you'd expect. We don't want to get carried away, though. We try not to do excessive allocation in the write path, so we cap the number of skbs we dynamically allocate. Probably calling it a "dynamic pool" is misleading. We were already trying to use a small fixed-size set of pre-allocated skbs before this patch, and this patch just provides a little headroom (with a ceiling, though) to accomodate network drivers that hang onto skbs, by allocating when needed. The d->skbpool_hd list of allocated skbs is necessary so that we can free them later. We didn't notice the need for this headroom until AoE targets got fast enough. Alternatives If the network layer never did a put_page on the pages in the bio's we get from the block layer, then it would be possible for us to hand skbs to the network layer and forget about them, allowing the network layer to free skbs itself (and thereby calling our own skb->destructor callback function if we needed that). In that case we could get rid of the pre-allocated skbs and also the d->skbpool_hd, instead just calling alloc_skb every time we wanted to transmit a packet. The slab allocator would effectively maintain the list of skbs. Besides a loss of CPU cache locality, the main concern with that approach the danger that it would increase the likelihood of deadlock when VM is trying to free pages by writing dirty data from the page cache through the aoe driver out to persistent storage on an AoE device. Right now we have a situation where we have pre-allocation that corresponds to how much we use, which seems ideal. Of course, there's still the separate issue of receiving the packets that tell us that a write has successfully completed on the AoE target. When memory is low and VM is using AoE to flush dirty data to free up pages, it would be perfect if there were a way for us to register a fast callback that could recognize write command completion responses. But I don't think the current problems with the receive side of the situation are a justification for exacerbating the problem on the transmit side. Signed-off-by: Ed L. Cashin <ecashin@coraid.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08aoe: user can ask driver to forget previously detected devicesEd L. Cashin
When an AoE device is detected, the kernel is informed, and a new block device is created. If the device is unused, the block device corresponding to remote device that is no longer available may be removed from the system by telling the aoe driver to "flush" its list of devices. Without this patch, software like GPFS and LVM may attempt to read from AoE devices that were discovered earlier but are no longer present, blocking until the I/O attempt times out. Signed-off-by: Ed L. Cashin <ecashin@coraid.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08aoe: eliminate goto and improve readabilityEd L. Cashin
Adam Richter suggested eliminating this goto. Signed-off-by: Ed L. Cashin <ecashin@coraid.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08aoe: mac_addr: avoid 64-bit arch compiler warningsEd L. Cashin
By returning unsigned long long, mac_addr does not generate compiler warnings on 64-bit architectures. Signed-off-by: Ed L. Cashin <ecashin@coraid.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08aoe: handle multiple network paths to AoE deviceEd L. Cashin
A remote AoE device is something can process ATA commands and is identified by an AoE shelf number and an AoE slot number. Such a device might have more than one network interface, and it might be reachable by more than one local network interface. This patch tracks the available network paths available to each AoE device, allowing them to be used more efficiently. Andrew Morton asked about the call to msleep_interruptible in the revalidate function. Yes, if a signal is pending, then msleep_interruptible will not return 0. That means we will not loop but will call aoenet_xmit with a NULL skb, which is a noop. If the system is too low on memory or the aoe driver is too low on frames, then the user can hit control-C to interrupt the attempt to do a revalidate. I have added a comment to the code summarizing that. Andrew Morton asked whether the allocation performed inside addtgt could use a more relaxed allocation like GFP_KERNEL, but addtgt is called when the aoedev lock has been locked with spin_lock_irqsave. It would be nice to allocate the memory under fewer restrictions, but targets are only added when the device is being discovered, and if the target can't be added right now, we can try again in a minute when then next AoE config query broadcast goes out. Andrew Morton pointed out that the "too many targets" message could be printed for failing GFP_ATOMIC allocations. The last patch in this series makes the messages more specific. Signed-off-by: Ed L. Cashin <ecashin@coraid.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08aoe: bring driver version number to 47Ed L. Cashin
Signed-off-by: Ed L. Cashin <ecashin@coraid.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>