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path: root/drivers/block/aoe/aoedev.c
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2013-09-11aoe: remove custom implementation of kbasename()Andy Shevchenko
In the kernel we have a nice helper that may be used here. This patch substitutes the custom implementation by the native function call. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11aoe: add AoE-target files to debugfsEd Cashin
Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03aoe: update copyright dateEd Cashin
Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03aoe: perform I/O completions in parallelEd Cashin
Some users have a large AoE target while others like to use many AoE targets at the same time. In the latter case, there is an opportunity to greatly improve aggregate throughput by allowing different threads to complete the I/O associated with each target. For 36 targets, 4 KiB read throughput roughly doubles, for example, with these changes in place. Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17aoe: fix use after free in aoedev_by_aoeaddr()Dan Carpenter
We should return NULL on failure instead of returning a freed pointer. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17aoe: use dynamic number of remote ports for AoE storage targetEd Cashin
Many AoE targets have four or fewer network ports, but some existing storage devices have many, and the AoE protocol sets no limit. This patch allows the use of more than eight remote MAC addresses per AoE target, while reducing the amount of memory used by the aoe driver in cases where there are many AoE targets with fewer than eight MAC addresses each. Signed-off-by: Ed Cashin <ecashin@coraid.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17aoe: avoid races between device destruction and discoveryEd Cashin
This change avoids a race that could result in a NULL pointer derference following a WARNing from kobject_add_internal, "don't try to register things with the same name in the same directory." The problem was found with a test that forgets and discovers an aoe device in a loop: while test ! -r /tmp/stop; do aoe-flush -a aoe-discover done The race was between aoedev_flush taking aoedevs out of the devlist, allowing a new discovery of the same AoE target to take place before the driver gets around to calling sysfs_remove_group. Fixing that one revealed another race between do_open and add_disk, and this patch avoids that, too. The fix required some care, because for flushing (forgetting) an aoedev, some of the steps must be performed under lock and some must be able to sleep. Also, for discovering a new aoedev, some steps might sleep. The check for a bad aoedev pointer remains from a time when about half of this patch was done, and it was possible for the bdev->bd_disk->private_data to become corrupted. The check should be removed eventually, but it is not expected to add significant overhead, occurring in the aoeblk_open routine. Signed-off-by: Ed Cashin <ecashin@coraid.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17aoe: improve handling of misbehaving network pathsEd Cashin
An AoE target can have multiple network ports used for AoE, and in the aoe driver, those are tracked by the aoetgt struct. These changes allow the aoe driver to handle network paths, or aoetgts, that are not working well, compared to the others. Paths that do not get responses despite the retransmission of AoE commands are marked as "tainted", and non-tainted paths are preferred. Meanwhile, the aoe driver attempts to "probe" the tainted path in the background by issuing reads of LBA 0 that are padded out to full (possibly jumbo-frame) size. If the probes get responses, then the path is "redeemed", and its taint is removed. This mechanism has been shown to be helpful in transparently handling and recovering from real-world network "brown outs" in ways that the earlier "shoot the help-needing target in the head" mechanism could not. Signed-off-by: Ed Cashin <ecashin@coraid.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17aoe: return real minor number for static minorsEd Cashin
The value returned by the static minor device number number allocator is the real minor number, so it must be multiplied by the supported number of partitions per aoedev. Without this fix the support for systems without udev is incomplete, and the few users of aoe on such systems will have surprising results when device nodes names do not match the AoE target. Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17aoe: initialize sysminor to avoid compiler warningEd Cashin
Because the minor_get and related functions use the return values for errors, the compiler doesn't know that sysminor will always either 1) be initialized in aoedev_by_aoeaddr by the call to minor_get, or 2) be unused as the "goto out" is executed. This patch avoids the compiler warning. Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17aoe: make error messages more specific in static minor allocationEd Cashin
For some special-purpose systems where udev isn't present, static allocation of minor numbers is desirable. This update distinguishes different failure scenarios, to help the user understand what went wrong. Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17aoe: commands in retransmit queue use new destination on failureEd Cashin
When one remote MAC address isn't working as a destination for AoE commands, the frames used to track information associated with the AoE commands are moved to a new aoetgt (defined by the tuple of {AoE major, AoE minor, target MAC address}). This patch makes sure that the frames on the queue for retransmits that need to be done are updated to use the new destination, so that retransmits will be sent through a working network path. Without this change, packets on the retransmit queue will be needlessly retransmitted to the unresponsive destination MAC, possibly causing premature target failure before there's time for the retransmit timer to run again, decide to retransmit again, and finally update the destination to a working MAC address on the AoE target. Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17aoe: improve network congestion handlingEd Cashin
The aoe driver already had some congestion handling, but it was limited in its ability to cope with the kind of congestion that can arise on more complex networks such as those involving paths through multiple ethernet switches. Some of the lessons from TCP's history of development can be applied to improving the congestion control and avoidance on AoE storage networks. These changes use familar concepts from Van Jacobson's "Congestion Avoidance and Control" paper from '88, without adding significant overhead. This patch depends on an upcoming patch that covers the failover case when AoE commands being retransmitted are transferred from one retransmit queue to another. Another upcoming patch increases the timing accuracy. Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17aoe: support the forgetting (flushing) of a user-specified AoE targetEd Cashin
Users sometimes want to cause the aoe driver to forget a particular previously discovered device when it is no longer online. The aoetools provide an "aoe-flush" command that users run to perform this administrative task. The changes below provide the support needed in the driver. Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06aoe: make dynamic block minor numbers the defaultEd Cashin
Because udev use is so widespread, making the old static mapping the default is too conservative, given the severe limitations it places on usable AoE addresses. Storage virtualization and larger shelves have made the old limitations too confining. These changes make the dynamic block device minor numbers the default, removing the limitations on usable AoE addresses. The static arrangement is still available with aoe_dyndevs=0, and the aoe-stat tool from the userland aoetools package, the user space counterpart to the aoe driver, recognizes the case where there is a mismatch between the minor number in sysfs and the minor number in a special device file. Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06aoe: retain static block device numbers for backwards compatibilityEd Cashin
The old mapping between AoE target shelf and slot addresses and the block device minor number is retained as a backwards-compatible feature, with a new "aoe_dyndevs" module parameter available for enabling dynamic block device minor numbers. Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06aoe: support more AoE addresses with dynamic block device minor numbersEd Cashin
The ATA over Ethernet protocol uses a major (shelf) and minor (slot) address to identify a particular storage target. These changes remove an artificial limitation the aoe driver imposes on the use of AoE addresses. For example, without these changes, the slot address has a maximum of 15, but users commonly use slot numbers much greater than that. The AoE shelf and slot address space is often used sparsely. Instead of using a static mapping between AoE addresses and the block device minor number, the block device minor numbers are now allocated on demand. Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06aoe: update copyright year in touched filesEd Cashin
Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06aoe: increase net_device reference count while using itEd Cashin
This change eliminates the danger that the user could rmmod the driver for a network interface that is being used for AoE by the aoe driver. Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06aoe: associate frames with the AoE storage targetEd Cashin
In the driver code, "target" and aoetgt refer to a particular remote interface on the AoE storage target. The latter is identified by its AoE major and minor addresses. Commands that are being sent to an AoE storage target {major, minor} can be sent or retransmitted to any of the remote MAC addresses associated with the AoE storage target. That is, frames are naturally associated with not an aoetgt (AoE major, AoE minor, remote MAC address) but an aoedev (AoE major, AoE minor). Making the code reflect that reality simplifies the driver, especially when the path to a remote MAC address becomes unusable. Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06aoe: become I/O request queue handler for increased user controlEd Cashin
To allow users to choose an elevator algorithm for their particular workloads, change from a make_request-style driver to an I/O-request-queue-handler-style driver. We have to do a couple of things that might be surprising. We manipulate the page _count directly on the assumption that we still have no guarantee that users of the block layer are prohibited from submitting bios containing pages with zero reference counts.[1] If such a prohibition now exists, I can get rid of the _count manipulation. Just as before this patch, we still keep track of the sk_buffs that the network layer still hasn't finished yet and cap the resources we use with a "pool" of skbs.[2] Now that the block layer maintains the disk stats, the aoe driver's diskstats function can go away. 1. https://lkml.org/lkml/2007/3/1/374 2. https://lkml.org/lkml/2007/7/6/241 Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06aoe: kernel thread handles I/O completions for simple lockingEd Cashin
Make the frames the aoe driver uses to track the relationship between bios and packets more flexible and detached, so that they can be passed to an "aoe_ktio" thread for completion of I/O. The frames are handled much like skbs, with a capped amount of preallocation so that real-world use cases are likely to run smoothly and degenerate gracefully even under memory pressure. Decoupling I/O completion from the receive path and serializing it in a process makes it easier to think about the correctness of the locking in the driver, especially in the case of a remote MAC address becoming unusable. [dan.carpenter@oracle.com: cleanup an allocation a bit] Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06aoe: for performance support larger packet payloadsEd Cashin
tAdd adds the ability to work with large packets composed of a number of segments, using the scatter gather feature of the block layer (biovecs) and the network layer (skb frag array). The motivation is the performance gained by using a packet data payload greater than a page size and by using the network card's scatter gather feature. Users of the out-of-tree aoe driver already had these changes, but since early 2011, they have complained of increased memory utilization and higher CPU utilization during heavy writes.[1] The commit below appears related, as it disables scatter gather on non-IP protocols inside the harmonize_features function, even when the NIC supports sg. commit f01a5236bd4b140198fbcc550f085e8361fd73fa Author: Jesse Gross <jesse@nicira.com> Date: Sun Jan 9 06:23:31 2011 +0000 net offloading: Generalize netif_get_vlan_features(). With that regression in place, transmits always linearize sg AoE packets, but in-kernel users did not have this patch. Before 2.6.38, though, these changes were working to allow sg to increase performance. 1. http://www.spinics.net/lists/linux-mm/msg15184.html Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28aoe: don't use flush_scheduled_work()Tejun Heo
flush_scheduled_work() is deprecated and scheduled to be removed. Directly cancel aoedev->work on free instead of depending on flush_scheduled_works(). Signed-off-by: Tejun Heo <tj@kernel.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.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>
2009-03-04aoe: 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>
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 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>
2008-09-21aoe: Use SKB interfaces for list management instead of home-grown stuff.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-29remove 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>
2008-02-08aoe: 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: 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: 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>
2007-10-10Drop 'size' argument from bio_endio and bi_end_ioNeilBrown
As bi_end_io is only called once when the reqeust is complete, the 'size' argument is now redundant. Remove it. Now there is no need for bio_endio to subtract the size completed from bi_size. So don't do that either. While we are at it, change bi_end_io to return void. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2006-11-22WorkStruct: make allyesconfigDavid Howells
Fix up for make allyesconfig. Signed-Off-By: David Howells <dhowells@redhat.com>
2006-10-18aoe: revert printk macrosEd L. Cashin
This patch addresses the concern that the aoe driver should not introduce unecessary conventions that must be learned by the reader. It reverts patch 6. Signed-off-by: "Ed L. Cashin" <ecashin@coraid.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-10-18aoe: zero copy write 2 of 2Ed L. Cashin
Avoid memory copy on writes. (This patch follows patch 4.) Signed-off-by: "Ed L. Cashin" <ecashin@coraid.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-10-18aoe: clean up printks via macrosEd L. Cashin
Use simple macros to clean up the printks. (This patch is reverted by the 14th patch to follow.) Signed-off-by: "Ed L. Cashin" <ecashin@coraid.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-10-18aoe: zero copy write 1 of 2Ed L. Cashin
Avoid memory copy on writes. (This patch depends on fixes in patch 9 to follow.) Although skb->len should not be set when working with linear skbuffs, the skb->tail pointer maintained by skb_put/skb_trim is not relevant to what happens when the skb_fill_page_desc function is called. This issue was raised without comment in linux-kernel and netdev earlier this month: http://thread.gmane.org/gmane.linux.kernel/446474/ http://thread.gmane.org/gmane.linux.network/45444/ So until there is something analogous to skb_put that works for zero-copy write skbuffs, we will do what the other callers of skb_fill_page_desc are doing. Signed-off-by: "Ed L. Cashin" <ecashin@coraid.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-10-18aoe: update copyright dateEd L. Cashin
Update the copyright year to 2006. Signed-off-by: "Ed L. Cashin" <ecashin@coraid.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-10-18aoe: eliminate isbusy messageEd L. Cashin
This message doesn't help users because the circumstance isn't problematic. Signed-off-by: "Ed L. Cashin" <ecashin@coraid.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-03-23[PATCH] aoe [2/8]: support dynamic resizing of AoE devicesEd L. Cashin
Allow the driver to recognize AoE devices that have changed size. Devices not in use are updated automatically, and devices that are in use are updated at user request. Signed-off-by: "Ed L. Cashin" <ecashin@coraid.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-09-07[PATCH] drivers: convert kcalloc to kzallocPekka Enberg
This patch converts kcalloc(1, ...) calls to use the new kzalloc() function. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-03[PATCH] aoe: allow multiple aoe devices to have the same macEd L Cashin
allow multiple aoe devices to have the same mac Signed-off-by: Ed L. Cashin <ecashin@coraid.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> diff -u b/drivers/block/aoe/aoedev.c b/drivers/block/aoe/aoedev.c
2005-04-18[PATCH] aoe 5/12: don't try to free null bufpoolecashin@coraid.com
don't try to free null bufpool Signed-off-by: Ed L. Cashin <ecashin@coraid.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-04-18[PATCH] aoe 2/12: allow multiple aoe devices with same MACecashin@coraid.com
allow multiple aoe devices with same MAC addr Signed-off-by: Ed L. Cashin <ecashin@coraid.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-04-16Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!