Add the API for a generic facility (FS-Cache) by which caches may declare them
selves open for business, and may obtain work to be done from network
filesystems. The header file is included by:
#include <linux/fscache-cache.h>
Documentation for the API is also added to:
Documentation/filesystems/caching/backend-api.txt
This API is not usable without the implementation of the utility functions
which will be added in further patches.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
Add the API for a generic facility (FS-Cache) by which filesystems (such as AFS
or NFS) may call on local caching capabilities without having to know anything
about how the cache works, or even if there is a cache:
+---------+
| | +--------------+
| NFS |--+ | |
| | | +-->| CacheFS |
+---------+ | +----------+ | | /dev/hda5 |
| | | | +--------------+
+---------+ +-->| | |
| | | |--+
| AFS |----->| FS-Cache |
| | | |--+
+---------+ +-->| | |
| | | | +--------------+
+---------+ | +----------+ | | |
| | | +-->| CacheFiles |
| ISOFS |--+ | /var/cache |
| | +--------------+
+---------+
General documentation and documentation of the netfs specific API are provided
in addition to the header files.
As this patch stands, it is possible to build a filesystem against the facility
and attempt to use it. All that will happen is that all requests will be
immediately denied as if no cache is present.
Further patches will implement the core of the facility. The facility will
transfer requests from networking filesystems to appropriate caches if
possible, or else gracefully deny them.
If this facility is disabled in the kernel configuration, then all its
operations will trivially reduce to nothing during compilation.
WHY NOT I_MAPPING?
==================
I have added my own API to implement caching rather than using i_mapping to do
this for a number of reasons. These have been discussed a lot on the LKML and
CacheFS mailing lists, but to summarise the basics:
(1) Most filesystems don't do hole reportage. Holes in files are treated as
blocks of zeros and can't be distinguished otherwise, making it difficult
to distinguish blocks that have been read from the network and cached from
those that haven't.
(2) The backing inode must be fully populated before being exposed to
userspace through the main inode because the VM/VFS goes directly to the
backing inode and does not interrogate the front inode's VM ops.
Therefore:
(a) The backing inode must fit entirely within the cache.
(b) All backed files currently open must fit entirely within the cache at
the same time.
(c) A working set of files in total larger than the cache may not be
cached.
(d) A file may not grow larger than the available space in the cache.
(e) A file that's open and cached, and remotely grows larger than the
cache is potentially stuffed.
(3) Writes go to the backing filesystem, and can only be transferred to the
network when the file is closed.
(4) There's no record of what changes have been made, so the whole file must
be written back.
(5) The pages belong to the backing filesystem, and all metadata associated
with that page are relevant only to the backing filesystem, and not
anything stacked atop it.
OVERVIEW
========
FS-Cache provides (or will provide) the following facilities:
(1) Caches can be added / removed at any time, even whilst in use.
(2) Adds a facility by which tags can be used to refer to caches, even if
they're not available yet.
(3) More than one cache can be used at once. Caches can be selected
explicitly by use of tags.
(4) The netfs is provided with an interface that allows either party to
withdraw caching facilities from a file (required for (1)).
(5) A netfs may annotate cache objects that belongs to it. This permits the
storage of coherency maintenance data.
(6) Cache objects will be pinnable and space reservations will be possible.
(7) The interface to the netfs returns as few errors as possible, preferring
rather to let the netfs remain oblivious.
(8) Cookies are used to represent indices, files and other objects to the
netfs. The simplest cookie is just a NULL pointer - indicating nothing
cached there.
(9) The netfs is allowed to propose - dynamically - any index hierarchy it
desires, though it must be aware that the index search function is
recursive, stack space is limited, and indices can only be children of
indices.
(10) Indices can be used to group files together to reduce key size and to make
group invalidation easier. The use of indices may make lookup quicker,
but that's cache dependent.
(11) Data I/O is effectively done directly to and from the netfs's pages. The
netfs indicates that page A is at index B of the data-file represented by
cookie C, and that it should be read or written. The cache backend may or
may not start I/O on that page, but if it does, a netfs callback will be
invoked to indicate completion. The I/O may be either synchronous or
asynchronous.
(12) Cookies can be "retired" upon release. At this point FS-Cache will mark
them as obsolete and the index hierarchy rooted at that point will get
recycled.
(13) The netfs provides a "match" function for index searches. In addition to
saying whether a match was made or not, this can also specify that an
entry should be updated or deleted.
FS-Cache maintains a virtual index tree in which all indices, files, objects
and pages are kept. Bits of this tree may actually reside in one or more
caches.
FSDEF
|
+------------------------------------+
| |
NFS AFS
| |
+--------------------------+ +-----------+
| | | |
homedir mirror afs.org redhat.com
| | |
+------------+ +---------------+ +----------+
| | | | | |
00001 00002 00007 00125 vol00001 vol00002
| | | | |
+---+---+ +-----+ +---+ +------+------+ +-----+----+
| | | | | | | | | | | | |
PG0 PG1 PG2 PG0 XATTR PG0 PG1 DIRENT DIRENT DIRENT R/W R/O Bak
| |
PG0 +-------+
| |
00001 00003
|
+---+---+
| | |
PG0 PG1 PG2
In the example above, two netfs's can be seen to be backed: NFS and AFS. These
have different index hierarchies:
(*) The NFS primary index will probably contain per-server indices. Each
server index is indexed by NFS file handles to get data file objects.
Each data file objects can have an array of pages, but may also have
further child objects, such as extended attributes and directory entries.
Extended attribute objects themselves have page-array contents.
(*) The AFS primary index contains per-cell indices. Each cell index contains
per-logical-volume indices. Each of volume index contains up to three
indices for the read-write, read-only and backup mirrors of those volumes.
Each of these contains vnode data file objects, each of which contains an
array of pages.
The very top index is the FS-Cache master index in which individual netfs's
have entries.
Any index object may reside in more than one cache, provided it only has index
children. Any index with non-index object children will be assumed to only
reside in one cache.
The FS-Cache overview can be found in:
Documentation/filesystems/caching/fscache.txt
The netfs API to FS-Cache can be found in:
Documentation/filesystems/caching/netfs-api.txt
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
Recruit a page flag to aid in cache management. The following extra flag is
defined:
(1) PG_fscache (PG_private_2)
The marked page is backed by a local cache and is pinning resources in the
cache driver.
If PG_fscache is set, then things that checked for PG_private will now also
check for that. This includes things like truncation and page invalidation.
The function page_has_private() had been added to make the checks for both
PG_private and PG_private_2 at the same time.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
The attached patch causes read_cache_pages() to release page-private data on a
page for which add_to_page_cache() fails. If the filler function fails, then
the problematic page is left attached to the pagecache (with appropriate flags
set, one presumes) and the remaining to-be-attached pages are invalidated and
discarded. This permits pages with caching references associated with them to
be cleaned up.
The invalidatepage() address space op is called (indirectly) to do the honours.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
Document the slow work thread pool.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
Make the slow work pool configurable through /proc/sys/kernel/slow-work.
(*) /proc/sys/kernel/slow-work/min-threads
The minimum number of threads that should be in the pool as long as it is
in use. This may be anywhere between 2 and max-threads.
(*) /proc/sys/kernel/slow-work/max-threads
The maximum number of threads that should in the pool. This may be
anywhere between min-threads and 255 or NR_CPUS * 2, whichever is greater.
(*) /proc/sys/kernel/slow-work/vslow-percentage
The percentage of active threads in the pool that may be used to execute
very slow work items. This may be between 1 and 99. The resultant number
is bounded to between 1 and one fewer than the number of active threads.
This ensures there is always at least one thread that can process very
slow work items, and always at least one thread that won't.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
Make the slow-work thread pool actually dynamic in the number of threads it
contains. With this patch, it will both create additional threads when it has
extra work to do, and cull excess threads that aren't doing anything.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
Create a dynamically sized pool of threads for doing very slow work items, such
as invoking mkdir() or rmdir() - things that may take a long time and may
sleep, holding mutexes/semaphores and hogging a thread, and are thus unsuitable
for workqueues.
The number of threads is always at least a settable minimum, but more are
started when there's more work to do, up to a limit. Because of the nature of
the load, it's not suitable for a 1-thread-per-CPU type pool. A system with
one CPU may well want several threads.
This is used by FS-Cache to do slow caching operations in the background, such
as looking up, creating or deleting cache objects.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
sg_rq_end_io() is called via rq->end_io. In some rare cases,
sg_rq_end_io calls blk_put_request/blk_rq_unmap_user (when a program
issuing a command has gone before the command completion; e.g. by
interrupting a program issuing a command before the command
completes).
We can't call blk_put_request/blk_rq_unmap_user in interrupt so the
commit c96952ed70 uses
execute_in_process_context().
The problem is that scsi_error_handler() calls rq->end_io too. We
can't call blk_put_request/blk_rq_unmap_user too in this path (we hold
q->queue_lock).
To avoid the above problem, in these rare cases, this patch always
uses schedule_work() instead of execute_in_process_context().
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
a2091_{detect,release}() can become static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
a3000_{detect,release}() can become static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Impact: code size reduction (possibly critical)
The x86 boot and decompression code has no use of the branch profiling
constructs, so disable them. This would bloat the setup code by as
much as 14K, eating up a fairly large chunk of the 32K area we are
guaranteed to have.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
- needs to use copy_from_user for iovec before passing it to
blk_rq_map_user_iov().
- before the block layer conversion, if ->dxfer_len and sum of iovec
disagrees, the shorter one wins. However, currently sg returns
-EINVAL. This restores the old behavior.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Firmware blob is little endian
Thanks to Stephen Rothwell for fixing typos
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Firmware blob is little endian looks like this...
unsigned char Version1
unsigned char Version2
unsigned char Version3
unsigned char Padding
unsigned short start_address
unsigned short data
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Le lundi 30 mars 2009, Chris Wright a écrit :
> q->queue could be ERR_PTR(-ENOMEM) which will break unwinding
> on error. Make iscsi_pool_free more defensive.
>
Making the freeing of q->queue dependent on q->pool being set looks
really weird (although it is correct at the moment. But this seems
to be fixable in a much simpler way.
With the benefit that only the error case is slowed down. In both
cases we have a problem if q->queue contains an error value but it's
not -ENOMEM. Apparently this can't happen today, but it doesn't feel
right to assume this will always be true. Maybe it's the right time
to fix this as well.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
cxgb3i_ddp_cleanup just calls ddp_release directly so there is
no reason for the wrapper. This patch just renames ddp_release
to cxgb3i_ddp_cleanup and removes the old wrapper function.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
- Merge cxgb3i_ddp.ko to cxgb3i.ko as there is no other users.
- Bump the driver version up to 1.0.2.
Signed-off-by: Karen Xie <kxie@chelsio.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Keep track of offloaded tcp connections per adapter. Close all of the
connections upon reset.
Signed-off-by: Karen Xie <kxie@chelsio.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Orignally from Karen Xie, but merge conflicts/errors fixed up by
Mike Christie.
Signed-off-by: Karen Xie <kxie@chelsio.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Re-initialize the ddp settings after chip reset. It includes re-initialize
the related registers and the ddp map.
Signed-off-by: Karen Xie <kxie@chelsio.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Add error notification handling function which is called during chip reset.
Signed-off-by: Karen Xie <kxie@chelsio.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
changes:
- set aac_cache=2 as default value to avoid performance problem
(Novell bugzilla #469922)
- Dell/PERC controller boot problem fixed (RedHat bugzilla #457552)
- WWN flag added to fix SLES10 SP1/SP2 drive detection problems
- 64-bit support changes
- DECLARE_PCI_DEVICE_TABLE macro added
- controller type changes
Signed-off-by: Achim Leubner <aacraid@adaptec.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Mention ATAPI. We could insert an essay about libata and ide-scsi etc but
the failure case is someone enables it which is just fine so keep it
simple.
(Revised text from suggestion by Matthew Wilcox)
Closes#7736
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This adds the support of a new SAS 6G controller (st_yel)
Signed-off-by: Ed Lin <ed.lin@promise.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Use config struct (st_card_info) for parameters of different controllers
Signed-off-by: Ed Lin <ed.lin@promise.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This adds the MSI support (default 0=off)
Signed-off-by: Ed Lin <ed.lin@promise.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
These are some small code fixes and changes, including:
- use 64 bit when possible
- remove some unnecessary code (in interrupt, queuecommand routine etc.)
- code change for reset handler
Signed-off-by: Ed Lin <ed.lin@promise.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
FIP is the new standard way to discover Fibre-Channel Forwarders (FCFs)
by sending solicitations and listening for advertisements from FCFs.
It also provides for keep-alives and period advertisements so that both
parties know they have connectivity. If the FCF loses connectivity to
the storage fabric, it can send a Link Reset to inform the E_node.
This version is also compatible with pre-FIP implementations, so no
configured selection between FIP mode and non-FIP mode is required.
We wait a couple seconds after sending the initial solicitation
and then send an old-style FLOGI. If we receive any FIP frames,
we use FIP only mode. If the old FLOGI receives a response,
we disable FIP mode. After every reset or link up, this
determination is repeated.
Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Adds include/scsi/fc/fc_fip.h for FIP protocol definitions.
Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The foce_softc mem was reserved by libfc_host_alloc as well as
by fcoe_host_alloc.
Removes one liner fcoe_host_alloc completely, instead directly calls
libfc_host_alloc to alloc scsi_host with libfc for just one fcoe_softc
as fcoe private data.
Moves libfc_host_alloc to libfc.h since it is a libfc API, placed
lport_priv API adjacent to libfc_host_alloc since this is related
to scsi_host priv data.
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Removes no where used several inline functions prefixed with skb_*
and be16_to_cpu.
Moves fcoe module specific func prototypes to fcoe.c from libfcoe.h,
moved only need for build.
Adds fcoe module header file fcoe.h and then moves fcoe module
specific fcoe_percpu_s and fcoe_softc to fcoe.h from libfcoe.h.
Moves all defines from fcoe.c to fcoe.h since now fcoe module
has its own header file fcoe.h.
[jejb: removed EXPORT_SYMBOL_GPL(fcoe_fc_crc) which caused a section mismatch]
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Moves these functions as-is from fcoe.c to libfcoe.c, since
they're are common routines:
- fcoe_wwn_from_mac
- fcoe_libfc_config
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Just sets up build environment for libfcoe module towards a
libfcoe library for libfc LLDs using FCoE as libfc transport.
Common library code to libfcoe is added in next patch.
Also, updated MODULE_LICENSE from "GPL" string to "GPL v2" for
libfc, libfcoe and fcoe modules to accurately match the licenses.
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Renames libfcoe.c to fcoe.c, fcoe.c becomes the only
.c file for fcoe.ko.
Also deleted "$Id: Makefile" from fcoe module Makefle.
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Moves only required code from fcoe_sw.c to libfcoe.c towards having
just one source file for fcoe module, this gets rid off default sw
transport code in a separate fcoe_sw.c file.
Very minor renaming along this move, dropped _sw_ or _SW_ use
in names and replaced them by _if_ as a auxiliary interface
functions. Now some of these funcs can be removed or merged with
other func after fcoe transport is gone, but that should be
in another patch to keep this patch simple.
Now the libfcoe.c file name for fcoe module doesn't go along well,
so the libfcoe.c file renaming to fcoe.c as the only single fcoe
module file is done in next patch to keep this patch clean
and small for review.
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The fcoe transport code was added for generic FCoE transport
infrastructure to allow additional offload related module loading
on demand, this is not required anymore after recently added
different offload approach by having offload related func ops
in netdev.
This patch removes fcoe transport related code use, calls functions
directly between existing libfcoe.c and fcoe_sw.c for now, for
example fcoe_sw_destroy and fcoe_sw_create calling.
The fcoe_sw.c and libfcoe.c code will be further consolidated in
later patches and then also the default fcoe sw transport code
file fcoe_sw.c will be completely removed.
The fcoe transport code files are completely removed in next
patch to keep this patch simple for reviewing.
[This patch is an update to a previous patch. This update
resolves a build error as well as fixes a defect related to
not calling fc_release_transport().]
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This patch adds support for dynamically created Rx threads
upon CPU hotplug events.
There were existing synchronization problems that this patch
attempts to resolve. The main problem had to do with fcoe_rcv()
running in a different context than the hotplug notifications.
This opened the possiblity that fcoe_rcv() would target a Rx
thread for a skb. However, that thread could become NULL if
the CPU was made offline.
This patch uses the Rx queue's (a skb_queue) lock to protect
the thread it's associated with and we use the 'thread' member
of the fcoe_percpu_s to determine if the thread is ready to
accept new skbs.
The patch also attempts to do a better job of cleaning up, both
if hotplug registration fails as well as when the module is
removed.
Contribution provided by Joe Eykholt <jeykholt@cisco.com> to
fix incorrect use of __cpuinitdata.
Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Remove the hotplug creation of dev_stats, we allocate for all possible CPUs
now when we allocate the lport.
v2: Durring the 2.6.30 merge window, before these patches were comitted,
'percpu_ptr' was renamed 'per_cpu_ptr'. This latest update updates this
patch for the name change.
Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Convert fcoe_percpu array to use the per-cpu variables
that the kernel provides. Use the kernel's functions to
access this structure.
The cpu member of the fcoe_percpu_s is no longer needed,
so this patch removes it too.
Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Currently the skb_queue is initialized every time the associated
CPU goes online. This patch has libfcoe initializing the skb_queue
for all possible CPUs when the module is loaded.
This patch also re-orders some declarations in the fcoe_rcv()
function so the structure declarations are grouped before
the primitive declarations.
Lastly, this patch converts all CPU indicies to use unsigned int
since CPU indicies should not be negative.
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Remove the creation of the symlink from the device to
it's class. On modern systems this is already created by
a udev rule and would WARN on load. On old systems it is
not needed, none of the current osd user-mode tools use
this link.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
