NeilBrown
d3374825ce
md: make devices disappear when they are no longer needed. ...
Currently md devices, once created, never disappear until the module
is unloaded. This is essentially because the gendisk holds a
reference to the mddev, and the mddev holds a reference to the
gendisk, this a circular reference.
If we drop the reference from mddev to gendisk, then we need to ensure
that the mddev is destroyed when the gendisk is destroyed. However it
is not possible to hook into the gendisk destruction process to enable
this.
So we drop the reference from the gendisk to the mddev and destroy the
gendisk when the mddev gets destroyed. However this has a
complication.
Between the call
__blkdev_get->get_gendisk->kobj_lookup->md_probe
and the call
__blkdev_get->md_open
there is no obvious way to hold a reference on the mddev any more, so
unless something is done, it will disappear and gendisk will be
destroyed prematurely.
Also, once we decide to destroy the mddev, there will be an unlockable
moment before the gendisk is unlinked (blk_unregister_region) during
which a new reference to the gendisk can be created. We need to
ensure that this reference can not be used. i.e. the ->open must
fail.
So:
1/ in md_probe we set a flag in the mddev (hold_active) which
indicates that the array should be treated as active, even
though there are no references, and no appearance of activity.
This is cleared by md_release when the device is closed if it
is no longer needed.
This ensures that the gendisk will survive between md_probe and
md_open.
2/ In md_open we check if the mddev we expect to open matches
the gendisk that we did open.
If there is a mismatch we return -ERESTARTSYS and modify
__blkdev_get to retry from the top in that case.
In the -ERESTARTSYS sys case we make sure to wait until
the old gendisk (that we succeeded in opening) is really gone so
we loop at most once.
Some udev configurations will always open an md device when it first
appears. If we allow an md device that was just created by an open
to disappear on an immediate close, then this can race with such udev
configurations and result in an infinite loop the device being opened
and closed, then re-open due to the 'ADD' even from the first open,
and then close and so on.
So we make sure an md device, once created by an open, remains active
at least until some md 'ioctl' has been made on it. This means that
all normal usage of md devices will allow them to disappear promptly
when not needed, but the worst that an incorrect usage will do it
cause an inactive md device to be left in existence (it can easily be
removed).
As an array can be stopped by writing to a sysfs attribute
echo clear > /sys/block/mdXXX/md/array_state
we need to use scheduled work for deleting the gendisk and other
kobjects. This allows us to wait for any pending gendisk deletion to
complete by simply calling flush_scheduled_work().
Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:10 +11:00
byteorder: only use linux/swab.h
2009-01-06 18:10:26 -08:00
V4L/DVB (10166): dvb frontend: stop using non-C99 compliant comments
2009-01-02 17:15:07 -02:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
2009-01-06 17:14:01 -08:00
NLM: Rewrite IPv4 privileged requester's check
2009-01-06 11:53:56 -05:00
mfd: Add WM8351 support
2009-01-04 12:17:42 +01:00
mlx4_core: Add support for multiple completion event vectors
2008-12-22 07:15:03 -08:00
mmc: Add mmc_vddrange_to_ocrmask() helper function
2008-12-31 18:18:13 +01:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
2009-01-07 11:31:52 -08:00
nfsd: get rid of NFSD_VERSION
2009-01-07 17:38:32 -05:00
md: make devices disappear when they are no longer needed.
2009-01-09 08:31:10 +11:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
2009-01-07 11:31:52 -08:00
sunrpc: add sv_maxconn field to svc_serv (try #3 )
2009-01-06 11:53:47 -05:00
USB: musb: use new platform data interface of musb to replace old one
2009-01-07 10:00:06 -08:00
uwb: remove unused include/linux/uwb/debug.h
2008-12-22 18:30:29 +00:00
wimax: export linux/wimax.h and linux/wimax/i2400m.h with headers_install
2009-01-07 10:00:22 -08:00
And here's a patch (to be applied on top of the last) which prevents
2009-01-02 10:19:37 -08:00
aio: make the lookup_ioctx() lockless
2008-12-29 08:29:50 +01:00
async: Asynchronous function calls to speed up kernel boot
2009-01-07 08:45:46 -08:00
atmel-mci: move atmel-mci.h file to include/linux
2009-01-05 16:35:31 +01:00
audit: validate comparison operations, store them in sane form
2009-01-04 15:14:42 -05:00
autofs4: improve parameter usage
2009-01-06 15:59:23 -08:00
autofs4: make autofs type usage explicit
2009-01-06 15:59:23 -08:00
fs/exec.c: make do_coredump() void
2009-01-06 15:59:29 -08:00
bio: add support for inlining a number of bio_vecs inside the bio
2008-12-29 08:29:50 +01:00
bitmap: test for constant as well as small size for inline versions
2008-12-30 09:05:13 +10:30
bitmap: find_last_bit()
2009-01-01 10:12:19 +10:30
block: get rid of elevator_t typedef
2008-12-29 08:29:50 +01:00
fs: introduce bgl_lock_ptr()
2009-01-04 13:33:20 -08:00
block: Supress Buffer I/O errors when SCSI REQ_QUIET flag set
2008-12-29 08:28:44 +01:00
CRED: Fix regression in cap_capable() as shown up by sys_faccessat() [ver #3 ]
2009-01-07 09:38:48 +11:00
mm: remove cgroup_mm_owner_callbacks
2009-01-06 15:59:01 -08:00
Sanitize gcc version header includes
2009-01-02 09:23:03 -08:00
Disallow gcc versions 3.{0,1}
2009-01-02 12:19:34 -08:00
Disallow gcc versions 4.1.{0,1}
2009-01-02 09:29:43 -08:00
Sanitize gcc version header includes
2009-01-02 09:23:03 -08:00
DRM: add mode setting support
2008-12-29 17:47:23 +10:00
cpumask: CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
2009-01-01 10:12:30 +10:30
oom: print triggering task's cpuset and mems allowed
2009-01-06 15:58:59 -08:00
libcrc32c: Add crc32c_le macro
2008-12-25 11:01:43 +11:00
crypto: hash - Export shash through hash
2008-12-25 11:01:33 +11:00
shrink struct dentry
2008-12-31 18:07:38 -05:00
net: add DCNA attribute to the BCN interface for DCB
2008-12-21 20:10:29 -08:00
debugfs: add helpers for exporting a size_t simple value
2009-01-07 10:00:16 -08:00
dm: support barriers on simple devices
2009-01-06 03:05:09 +00:00
driver core: add root_device_register()
2009-01-06 10:44:33 -08:00
intel-iommu: fix build error with INTR_REMAP=y and DMAR=n
2009-01-04 11:00:05 +01:00
intel-iommu: kill off duplicate def of dmar_disabled
2009-01-03 11:57:35 +01:00
DMI: add dmi_match
2008-12-29 07:39:34 -05:00
quota: Split off quota tree handling into a separate file
2009-01-05 08:40:21 -08:00
quota: Unexport dqblk_v1.h and dqblk_v2.h
2009-01-05 08:40:25 -08:00
quota: Unexport dqblk_v1.h and dqblk_v2.h
2009-01-05 08:40:25 -08:00
block: get rid of elevator_t typedef
2008-12-29 08:29:50 +01:00
fs: introduce bgl_lock_ptr()
2009-01-04 13:33:20 -08:00
fs: introduce bgl_lock_ptr()
2009-01-04 13:33:20 -08:00
SLUB: failslab support
2008-12-29 11:27:46 +02:00
fb: SH-5 uses __raw I/O accessors now also, drop the special casing.
2008-12-22 18:44:05 +09:00
filp_cachep can be static in fs/file_table.c
2008-12-31 18:07:42 -05:00
async: make the final inode deletion an asynchronous event
2009-01-07 08:47:24 -08:00
take init_fs to saner place
2008-12-31 18:07:42 -05:00
ftrace: enable format arguments checking
2008-12-21 09:46:45 +01:00
tty_port: Add a port level carrier detect operation
2009-01-02 10:19:38 -08:00
block: add one-hit cache for disk partition lookup
2008-12-29 08:29:51 +01:00
mm: remove GFP_HIGHUSER_PAGECACHE
2009-01-06 15:59:01 -08:00
Merge branch 'core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2008-12-30 16:10:19 -08:00
HID: avoid sparse warning in HID_COMPAT_LOAD_DRIVER
2009-01-04 01:00:53 +01:00
HID: add phys and name ioctls to hidraw
2009-01-04 01:00:51 +01:00
mm: report the MMU pagesize in /proc/pid/smaps
2009-01-06 15:58:58 -08:00
i2c: Drop I2C_CLASS_CAM_DIGITAL
2009-01-07 14:29:17 +01:00
ide: move read_sff_dma_status() method to 'struct ide_dma_ops'
2009-01-06 17:21:02 +01:00
take init_fs to saner place
2008-12-31 18:07:42 -05:00
Merge branch 'topic/jack-mechanical' into to-push
2008-12-25 11:40:29 +01:00
VT-d: remove now unused intel_iommu_found function
2009-01-03 14:11:08 +01:00
Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2009-01-06 17:10:53 -08:00
introcude linux/iommu.h for an iommu api
2009-01-03 14:10:09 +01:00
resource: allow MMIO exclusivity for device drivers
2009-01-07 11:12:32 -08:00
Merge branch 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2009-01-02 11:44:09 -08:00
genirq: provide irq_to_desc() to non-genirq architectures too
2009-01-05 14:53:30 +01:00
tty: Introduce some close helpers for ports
2009-01-02 10:19:40 -08:00
jbd2: Add buffer triggers
2009-01-05 08:40:30 -08:00
optimize attribute timeouts for "noac" and "actimeo=0"
2008-12-23 15:21:56 -05:00
jbd2: Add buffer triggers
2009-01-05 08:40:30 -08:00
wimax: export linux/wimax.h and linux/wimax/i2400m.h with headers_install
2009-01-07 10:00:22 -08:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
2009-01-06 17:02:07 -08:00
[PATCH] idle cputime accounting
2008-12-31 15:11:46 +01:00
driver core: Remove completion from struct klist_node
2009-01-06 10:44:30 -08:00
kprobes: support probing module __exit function
2009-01-06 15:59:21 -08:00
KVM: x86: Rework user space NMI injection as KVM_CAP_USER_NMI
2008-12-31 16:55:47 +02:00
KVM: change KVM to use IOMMU API
2009-01-03 14:11:07 +01:00
lguest: move the initial guest page table creation code to the host
2008-12-30 09:26:11 +10:30
libata: perform port detach in EH
2008-12-28 22:43:21 -05:00
Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2008-12-30 16:20:19 -08:00
Input: map_to_7segment.h - convert to __inline__ for userspace
2008-12-29 04:59:31 -08:00
mm: show node to memory section relationship with symlinks in sysfs
2009-01-06 15:59:00 -08:00
mm: show node to memory section relationship with symlinks in sysfs
2009-01-06 15:59:00 -08:00
mm: cleanup: remove #ifdef CONFIG_MIGRATION
2009-01-06 15:59:00 -08:00
mm: invoke oom-killer from page fault
2009-01-06 15:58:58 -08:00
aio: make the lookup_ioctx() lockless
2008-12-29 08:29:50 +01:00
module: add within_module_core() and within_module_init()
2009-01-06 15:59:20 -08:00
module: fix module loading failure of large kernel modules for parisc
2009-01-05 08:40:13 +10:30
vfs: introduce helper function to safely NUL-terminate symlinks
2008-12-31 18:07:38 -05:00
trivial: fix an -> a typos in documentation and comments
2009-01-06 11:28:07 +01:00
gro: Add page frag support
2009-01-04 16:13:40 -08:00
nfsd: last_byte_offset
2009-01-07 17:38:31 -05:00
optimize attribute timeouts for "noac" and "actimeo=0"
2008-12-23 15:21:56 -05:00
NFSv4: Remove nfs_client->cl_sem
2008-12-23 15:21:45 -05:00
NFS: add "[no]resvport" mount option
2008-12-23 15:21:37 -05:00
NFSv4: Convert the open and close ops to use fmode
2008-12-23 15:21:56 -05:00
mac80211: Fix HT channel selection
2008-12-19 15:22:54 -05:00
mm: show node to memory section relationship with symlinks in sysfs
2009-01-06 15:59:00 -08:00
of/gpio: Implement of_gpio_count()
2008-12-21 14:21:14 +11:00
usb host: Oxford OXU210HP HCD driver.
2009-01-07 09:59:50 -08:00
badpage: simplify page_alloc flag check+clear
2009-01-06 15:59:07 -08:00
fs: symlink write_begin allocation context fix
2009-01-04 13:33:20 -08:00
mm: get rid of pagevec_release_nonlru()
2009-01-06 15:59:00 -08:00
PCI hotplug: introduce functions for ACPI slot detection
2009-01-07 11:13:11 -08:00
x86/PCI: Do not use interrupt links for devices using MSI-X
2009-01-07 11:13:25 -08:00
PCI hotplug: introduce functions for ACPI slot detection
2009-01-07 11:13:11 -08:00
Resurrect IT8172 IDE controller driver
2009-01-06 17:21:01 +01:00
PCI: pciehp: cleanup register and field definitions
2009-01-07 11:13:22 -08:00
Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2009-01-06 17:10:04 -08:00
PM: Simplify the new suspend/hibernation framework for devices
2009-01-06 10:44:29 -08:00
Fix misspellings in pm.h macros
2009-01-06 10:44:30 -08:00
poll: allow f_op->poll to sleep
2009-01-06 15:59:12 -08:00
power_supply: Add cold to the POWER_SUPPLY_HEALTH report values
2009-01-04 12:17:39 +01:00
x86, bts: add fork and exit handling
2008-12-20 09:15:46 +01:00
qnx: include <linux/types.h> for definitions of __[us]{8,16,32,64} types
2009-01-07 21:44:20 +01:00
qnx: include <linux/types.h> for definitions of __[us]{8,16,32,64} types
2009-01-07 21:44:20 +01:00
quota: Unexport dqblk_v1.h and dqblk_v2.h
2009-01-05 08:40:25 -08:00
quota: Export dquot_alloc() and dquot_destroy() functions
2009-01-05 08:40:25 -08:00
mm lockless pagecache barrier fix
2009-01-05 18:31:12 -08:00
sparseirq: move set/get_timer_rand_state back to .c
2009-01-03 12:01:23 -08:00
cpumask: convert RCU implementations
2009-01-01 10:12:26 +10:30
rcu: eliminate synchronize_rcu_xxx macro
2009-01-05 10:18:08 +01:00
Merge branch 'oprofile-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2008-12-30 17:31:25 -08:00
rapidio: remove excess kernel-doc notation
2009-01-06 15:59:28 -08:00
badpage: remove vma from page_remove_rmap
2009-01-06 15:59:07 -08:00
rtc: add alarm/update irq interfaces
2009-01-04 13:33:20 -08:00
Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2009-01-06 17:10:33 -08:00
Merge branch 'next' into for-linus
2009-01-07 09:58:22 +11:00
cpumask: Use nr_cpu_ids in seq_cpumask
2008-12-30 09:05:19 +10:30
serial: RS485 ioctl structure uses __u32 include linux/types.h
2009-01-02 10:19:42 -08:00
Serial: Allow port type to be specified when calling serial8250_register_port.
2009-01-02 10:19:43 -08:00
Serial: UART driver changes for Cavium OCTEON.
2009-01-02 10:19:43 -08:00
Merge branches 'topic/fixes', 'topic/cleanups' and 'topic/documentation' into for-linus
2008-12-29 11:45:47 +02:00
cpumask: smp_call_function_many()
2008-12-30 09:05:16 +10:30
stop_machine: introduce stop_machine_create/destroy.
2009-01-05 08:40:14 +10:30
Fix up 64-bit byte swaps for most 32-bit architectures
2009-01-06 21:17:57 -08:00
badpage: zap print_bad_pte on swap and file
2009-01-06 15:59:07 -08:00
swiotlb: add hwdev to swiotlb_phys_to_bus() / swiotlb_sg_to_bus()
2008-12-28 09:54:52 +01:00
inotify: fix type errors in interfaces
2009-01-05 11:54:29 -05:00
cpumask: make CONFIG_NR_CPUS always valid.
2008-12-30 09:05:12 +10:30
cpumask: convert kernel time functions
2009-01-01 10:12:25 +10:30
sched_clock: prevent scd->clock from moving backwards, take #2
2008-12-31 09:53:21 +01:00
sched: add SD_BALANCE_NEWIDLE at MC and CPU level for sched_mc>0
2008-12-19 09:21:55 +01:00
tty: Introduce some close helpers for ports
2009-01-02 10:19:40 -08:00
pty: simplify resize
2009-01-02 10:19:36 -08:00
linux/types.h: Don't depend on __GNUC__ for __le64/__be64
2009-01-07 11:27:12 -08:00
uio: make uio_info's name and version const
2009-01-06 10:44:44 -08:00
USB: remove info() macro from usb.h
2009-01-07 10:00:14 -08:00
USB: storage: add last-sector hacks
2009-01-07 10:00:11 -08:00
V4L/DVB (10141): v4l2: debugging API changed to match against driver name instead of ID.
2009-01-02 17:11:52 -02:00
virtio: avoid implicit use of Linux page size in balloon interface
2008-12-30 09:26:04 +10:30
virtio_console: support console resizing
2008-12-30 09:26:10 +10:30
virtio: Don't use PAGE_SIZE for vring alignment in virtio_pci.
2008-12-30 09:25:58 +10:30
virtio: hand virtio ring alignment as argument to vring_new_virtqueue
2008-12-30 09:26:03 +10:30
mm: make vread() and vwrite() declaration
2009-01-06 15:59:05 -08:00
wimax: headers for kernel API and user space interaction
2009-01-07 10:00:16 -08:00
fs: remove WB_SYNC_HOLD
2009-01-06 15:59:09 -08:00
