NeilBrown 0feae5c47a [PATCH] Fix dcache race during umount ... The race is that the shrink_dcache_memory shrinker could get called while a filesystem is being unmounted, and could try to prune a dentry belonging to that filesystem. If it does, then it will call in to iput on the inode while the dentry is no longer able to be found by the umounting process. If iput takes a while, generic_shutdown_super could get all the way though shrink_dcache_parent and shrink_dcache_anon and invalidate_inodes without ever waiting on this particular inode. Eventually the superblock gets freed anyway and if the iput tried to touch it (which some filesystems certainly do), it will lose. The promised "Self-destruct in 5 seconds" doesn't lead to a nice day. The race is closed by holding s_umount while calling prune_one_dentry on someone else's dentry. As a down_read_trylock is used, shrink_dcache_memory will no longer try to prune the dentry of a filesystem that is being unmounted, and unmount will not be able to start until any such active prune_one_dentry completes. This requires that prune_dcache *knows* which filesystem (if any) it is doing the prune on behalf of so that it can be careful of other filesystems. shrink_dcache_memory isn't called it on behalf of any filesystem, and so is careful of everything. shrink_dcache_anon is now passed a super_block rather than the s_anon list out of the superblock, so it can get the s_anon list itself, and can pass the superblock down to prune_dcache. If prune_dcache finds a dentry that it cannot free, it leaves it where it is (at the tail of the list) and exits, on the assumption that some other thread will be removing that dentry soon. To try to make sure that some work gets done, a limited number of dnetries which are untouchable are skipped over while choosing the dentry to work on. I believe this race was first found by Kirill Korotaev. Cc: Jan Blunck <jblunck@suse.de> Acked-by: Kirill Korotaev <dev@openvz.org> Cc: Olaf Hering <olh@suse.de> Acked-by: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>		2006-06-22 15:05:57 -07:00
..
amba
byteorder
dvb
hdlc
isdn
lockd
mmc	[ARM] 3531/1: i.MX/MX1 SD/MMC ensure, that clock are stopped before new command and cleanups	2006-05-19 21:48:03 +01:00
mtd	Merge git://git.infradead.org/hdrcleanup-2.6	2006-06-20 15:10:08 -07:00
netfilter	Merge git://git.infradead.org/hdrcleanup-2.6	2006-06-20 15:10:08 -07:00
netfilter_arp
netfilter_bridge
netfilter_ipv4	Merge git://git.infradead.org/hdrcleanup-2.6	2006-06-20 15:10:08 -07:00
netfilter_ipv6
nfsd
raid
spi	[PATCH] SPI: busnum == 0 needs to work	2006-05-16 14:33:57 -07:00
sunrpc
tc_act
tc_ematch
usb	[PATCH] USB: move <linux/usb_input.h> to <linux/usb/input.h>	2006-06-21 15:04:18 -07:00
8250_pci.h
a.out.h
ac97_codec.h
acct.h
acpi.h
adb.h
adfs_fs_i.h
adfs_fs_sb.h
adfs_fs.h
affs_fs.h
affs_hardblocks.h	Include <linux/types.h> and use __uXX types in <linux/affs_hardblocks.h>	2006-05-04 15:49:24 +01:00
agp_backend.h
agpgart.h
aio_abi.h
aio.h
amifd.h
amifdreg.h
amigaffs.h
apm_bios.h
arcdevice.h
arcfb.h
ata.h
atalk.h
atm_eni.h
atm_he.h
atm_idt77105.h
atm_nicstar.h
atm_suni.h
atm_tcp.h
atm_zatm.h
atm.h
atmapi.h
atmarp.h
atmbr2684.h
atmclip.h
atmdev.h
atmioc.h
atmlec.h
atmmpc.h
atmppp.h
atmsap.h
atmsvc.h
attribute_container.h
audit.h	Merge branch 'audit.b21' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current	2006-06-20 15:37:56 -07:00
auto_fs4.h
auto_fs.h
auxvec.h
awe_voice.h
ax25.h
b1lli.h
b1pcmcia.h
backing-dev.h
backlight.h
baycom.h
bcd.h
bfs_fs.h
binfmts.h
bio.h
bit_spinlock.h
bitmap.h
bitops.h
blkdev.h	Merge master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6	2006-06-21 11:18:25 -07:00
blkpg.h
blktrace_api.h
blockgroup_lock.h
bootmem.h
bpqether.h
buffer_head.h
cache.h
calc64.h
capability.h
capi.h
cciss_ioctl.h
cd1400.h
cdev.h
cdk.h
cdrom.h
chio.h
circ_buf.h
clk.h
cm4000_cs.h
cn_proc.h
cobalt-nvram.h
coda_cache.h
coda_fs_i.h
coda_linux.h
coda_proc.h
coda_psdev.h
coda.h
coff.h
com20020.h
compat_ioctl.h
compat.h
compiler-gcc3.h
compiler-gcc4.h
compiler-gcc.h
compiler-intel.h
compiler.h	Restore __attribute_const__ to user-visibility in linux/compiler.h...for now	2006-05-04 00:41:02 +01:00
completion.h
comstats.h
concap.h
config.h
configfs.h
connector.h
console_struct.h
console.h	Add support for suspending and resuming the whole console subsystem	2006-06-19 18:16:01 -07:00
consolemap.h
cpu.h
cpufreq.h
cpumask.h
cpuset.h
cramfs_fs_sb.h
cramfs_fs.h	Include <linux/types.h> and use __uXX types in <linux/cramfs_fs.h>	2006-05-04 17:50:04 +01:00
crash_dump.h
crc16.h
crc32.h
crc32c.h
crc-ccitt.h
crypto.h
cryptohash.h
ctype.h
cuda.h
cyclades.h
cyclomx.h
cycx_cfm.h
cycx_drv.h
cycx_x25.h
dcache.h	[PATCH] Fix dcache race during umount	2006-06-22 15:05:57 -07:00
dccp.h
dcookies.h
debugfs.h
delay.h
devfs_fs_kernel.h
devfs_fs.h
device-mapper.h
device.h	[PATCH] Driver Core: Make dev_info and friends print the bus name if there is no driver	2006-06-21 12:40:49 -07:00
devpts_fs.h
dio.h
dirent.h
divert.h	Use __uXX types in <linux/divert.h> for struct divert_blk et al.	2006-05-04 15:07:59 +01:00
dm9000.h
dm-ioctl.h
dma-mapping.h	dl2k: use DMA_48BIT_MASK constant	2006-05-10 14:04:22 -07:00
dmaengine.h	[I/OAT]: Utility functions for offloading sk_buff to iovec copies	2006-06-17 21:25:46 -07:00
dmapool.h
dmi.h
dn.h
dnotify.h
dqblk_v1.h
dqblk_v2.h
dqblk_xfs.h
ds1286.h
ds1742rtc.h
ds17287rtc.h
dtlk.h
edd.h
efi.h
efs_dir.h
efs_fs_i.h
efs_fs_sb.h
efs_fs.h
efs_vh.h
eisa.h
elevator.h	[PATCH] elevator switching race	2006-06-08 15:14:23 -07:00
elf-em.h
elf-fdpic.h
elf.h
elfcore.h
err.h
errno.h
errqueue.h
etherdevice.h
ethtool.h
eventpoll.h
ext2_fs_sb.h
ext2_fs.h
ext3_fs_i.h
ext3_fs_sb.h
ext3_fs.h	Remove private struct dx_hash_info from public view in <linux/ext3_fs.h>	2006-05-04 17:28:26 +01:00
ext3_jbd.h
fadvise.h
fb.h
fcdevice.h
fcntl.h
fd1772.h
fd.h
fddidevice.h
fdreg.h
file.h
filter.h
firmware.h	[PATCH] drivers/base/firmware_class.c: cleanups	2006-05-21 12:59:19 -07:00
flat.h
font.h
fs_enet_pd.h
fs_struct.h
fs_uart_pd.h	[PATCH] ppc32 CPM_UART: fixes and improvements	2006-05-03 23:06:44 +10:00
fs.h	[PATCH] remove steal_locks()	2006-06-22 15:05:57 -07:00
fsl_devices.h	[PATCH] spi: add spi master driver for Freescale MPC83xx SPI controller	2006-05-21 12:59:19 -07:00
fsnotify.h	[PATCH] log more info for directory entry change events	2006-06-20 05:25:28 -04:00
ftape-header-segment.h
ftape-vendors.h
ftape.h
fuse.h
futex.h
gameport.h
gen_stats.h
genalloc.h
generic_serial.h
genetlink.h
genhd.h
gfp.h
gigaset_dev.h
hardirq.h
harrier_defs.h
hash.h
hayesesp.h
hdlc.h
hdlcdrv.h
hdpu_features.h
hdreg.h
hdsmart.h
hiddev.h
highmem.h
highuid.h
hil_mlc.h
hil.h
hippidevice.h
hp_sdc.h
hpet.h
hpfs_fs.h
hrtimer.h
hugetlb.h
hwmon-sysfs.h
hwmon-vid.h
hwmon.h
hysdn_if.h
i2c-algo-bit.h
i2c-algo-ite.h
i2c-algo-pca.h
i2c-algo-pcf.h
i2c-algo-sgi.h
i2c-algo-sibyte.h
i2c-dev.h
i2c-id.h
i2c-isa.h
i2c-pxa.h
i2c.h
i2o-dev.h	Use __uXX types in <linux/i2o_dev.h>, include <linux/ioctl.h> too	2006-05-04 17:32:44 +01:00
i2o.h	[PATCH] I2O: Bugfixes to get I2O working again	2006-06-10 11:02:05 -07:00
i8k.h
ibmtr.h
icmp.h
icmpv6.h
ide.h
idr.h
if_arcnet.h
if_arp.h
if_bonding.h
if_bridge.h
if_cablemodem.h
if_ec.h
if_eql.h
if_ether.h
if_fc.h
if_fddi.h	Remove struct fddi_statistics from user view in <linux/if_fddi.h>	2006-05-16 23:25:37 +01:00
if_frad.h
if_hippi.h
if_infiniband.h
if_ltalk.h
if_packet.h
if_plip.h
if_ppp.h
if_pppox.h
if_shaper.h
if_slip.h
if_strip.h
if_tr.h
if_tun.h
if_tunnel.h
if_vlan.h
if_wanpipe_common.h
if_wanpipe.h
if.h
igmp.h	[IPV4] igmp: Fixup struct ip_mc_list::multiaddr type	2006-06-17 21:29:37 -07:00
in6.h
in_route.h
in.h
inet_diag.h
inet.h
inetdevice.h
init_task.h
init.h
initrd.h
inotify.h	[PATCH] inotify (4/5): allow watch removal from event handler	2006-06-20 05:25:19 -04:00
input.h	Merge git://git.infradead.org/hdrcleanup-2.6	2006-06-20 15:10:08 -07:00
interrupt.h
io.h	[PATCH] add __iowrite64_copy	2006-06-20 20:24:58 -07:00
ioc3.h
ioc4.h
ioctl32.h
ioctl.h
ioport.h
ioprio.h
ip6_tunnel.h
ip_mp_alg.h
ip.h
ipc.h
ipmi_msgdefs.h
ipmi_smi.h
ipmi.h
ipsec.h
ipv6_route.h
ipv6.h
ipx.h
irda.h
irq_cpustat.h
irq.h
isa.h	[PATCH] Driver model: add ISA bus	2006-06-21 12:40:49 -07:00
isapnp.h
isdn_divertif.h
isdn_ppp.h
isdn.h
isdnif.h
isicom.h
iso_fs.h
istallion.h
ite_gpio.h
ixjuser.h
jbd.h
jffs2.h	Merge git://git.infradead.org/jffs2-xattr-2.6	2006-05-20 17:27:32 +01:00
jffs.h
jhash.h
jiffies.h
journal-head.h
joystick.h	Switch to __s32 types in joystick.h instead of C99 types for consistency.	2006-06-03 00:27:53 +01:00
kallsyms.h
kbd_diacr.h
kbd_kern.h
kd.h
kdev_t.h
kernel_stat.h
kernel.h	[PATCH] symbol_put_addr() locks kernel	2006-05-15 11:20:55 -07:00
kernelcapi.h
kexec.h
key-ui.h
key.h	[PATCH] Keys: Fix race between two instantiators of a key	2006-06-22 15:05:56 -07:00
keyboard.h
keyctl.h
kfifo.h
klist.h
kmalloc_sizes.h
kmod.h
kobj_map.h
kobject.h	[PATCH] Driver Core: Add /sys/hypervisor when needed	2006-06-21 12:40:48 -07:00
kprobes.h
kref.h
kthread.h
ktime.h
lapb.h
lcd.h
leds.h
libata.h
libps2.h
limits.h
linkage.h
linux_logo.h
list.h
llc.h
loop.h
lp.h
m48t86.h	[PATCH] m48t86: ia64 build fix	2006-06-05 12:29:17 -07:00
major.h
matroxfb.h
mbcache.h
mc6821.h
mc146818rtc.h
mca-legacy.h
mca.h
memory_hotplug.h
memory.h
mempolicy.h	Merge git://git.infradead.org/hdrcleanup-2.6	2006-06-20 15:10:08 -07:00
mempool.h
meye.h
migrate.h
mii.h
minix_fs.h
miscdevice.h
mm_inline.h
mm.h
mman.h
mmtimer.h
mmzone.h	Merge git://git.infradead.org/hdrcleanup-2.6	2006-06-20 15:10:08 -07:00
mod_devicetable.h
module.h	Merge git://git.infradead.org/hdrcleanup-2.6	2006-06-20 15:10:08 -07:00
moduleloader.h
moduleparam.h
mount.h
mpage.h
mqueue.h
mroute.h
msdos_fs.h
msg.h
mtio.h
mutex-debug.h
mutex.h
mv643xx.h
n_r3964.h
namei.h
namespace.h
nbd.h	Use __uXX types in user-visible structures in <linux/nbd.h>	2006-05-04 02:55:50 +01:00
ncp_fs_i.h
ncp_fs_sb.h
ncp_fs.h
ncp_mount.h
ncp_no.h
ncp.h
net.h
netdevice.h	Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6	2006-06-20 17:39:53 -07:00
netfilter_arp.h
netfilter_bridge.h
netfilter_decnet.h
netfilter_ipv4.h
netfilter_ipv6.h
netfilter_logging.h
netfilter.h
netlink.h
netpoll.h
netrom.h
nfs2.h
nfs3.h
nfs4_acl.h
nfs4_mount.h
nfs4.h
nfs_fs_i.h
nfs_fs_sb.h
nfs_fs.h
nfs_idmap.h
nfs_mount.h
nfs_page.h
nfs_xdr.h
nfs.h
nfsacl.h
nfsd_idmap.h
nls.h
nmi.h
node.h
nodemask.h
notifier.h
nubus.h
numa.h
nvram.h
openprom_fs.h
oprofile.h
page-flags.h
pagemap.h
pagevec.h
param.h
parport_pc.h
parport.h
parser.h
patchkey.h
pci_ids.h	Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6	2006-06-19 18:55:56 -07:00
pci_regs.h	[PATCH] PCI: Add PCI_CAP_ID_VNDR	2006-06-22 15:05:56 -07:00
pci-acpi.h	[PATCH] PCI: fix pciehp compile issue when CONFIG_ACPI is not enabled	2006-06-11 14:02:27 -07:00
pci.h	Merge git://git.infradead.org/hdrcleanup-2.6	2006-06-20 15:10:08 -07:00
pcieport_if.h
percpu_counter.h
percpu.h
personality.h
pfkeyv2.h	[PFKEYV2]: Fix inconsistent typing in struct sadb_x_kmprivate.	2006-06-17 22:54:03 -07:00
pfn.h
pg.h
phonedev.h
phy.h
pid.h
pipe_fs_i.h	[PATCH] splice: LRU fixups	2006-05-04 06:55:12 +02:00
pkt_cls.h
pkt_sched.h
pktcdvd.h
platform_device.h
pm_legacy.h
pm.h
pmu.h
pnp.h
pnpbios.h
poll.h
posix_acl_xattr.h
posix_acl.h
posix_types.h
posix-timers.h
ppdev.h
ppp_channel.h
ppp_defs.h	Remove PPP_FCS from user view in <linux/ppp_defs.h>, remove __P mess entirely	2006-05-04 12:07:37 +01:00
ppp-comp.h
prctl.h
preempt.h
prefetch.h
prio_tree.h
proc_fs.h
profile.h
ps2esdi.h
ptrace.h
qic117.h
qnx4_fs.h
qnxtypes.h
quota.h
quotaio_v1.h
quotaio_v2.h
quotaops.h
radeonfb.h
radix-tree.h
raid_class.h
ramfs.h
random.h
raw.h
rbtree.h	[RBTREE] Switch rb_colour() et al to en_US spelling of 'color' for consistency	2006-06-05 20:19:05 +01:00
rcupdate.h	[PATCH] RCU: introduce rcu_needs_cpu() interface	2006-05-15 11:20:55 -07:00
reboot_fixups.h
reboot.h
reiserfs_acl.h
reiserfs_fs_i.h
reiserfs_fs_sb.h
reiserfs_fs.h
reiserfs_xattr.h
relay.h
resource.h
rio_drv.h
rio_ids.h
rio_regs.h
rio.h
rmap.h
romfs_fs.h
root_dev.h
rose.h
route.h
rslib.h
rtc.h
rtnetlink.h
rwsem-spinlock.h
rwsem.h
sc26198.h
scatterlist.h
scc.h
sched.h	Merge branch 'audit.b21' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current	2006-06-20 15:37:56 -07:00
screen_info.h
sctp.h
scx200_gpio.h
scx200.h
sdla_fr.h
sdla.h
seccomp.h
securebits.h
security.h	[PATCH] selinux: add hooks for key subsystem	2006-06-22 15:05:55 -07:00
selection.h
selinux_netlink.h
selinux.h	[SECMARK]: Add SELinux exports	2006-06-17 21:29:55 -07:00
sem.h
seq_file.h
seqlock.h
serial167.h
serial_8250.h
serial_core.h	Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm	2006-06-20 17:52:36 -07:00
serial_ip3106.h
serial_reg.h
serial.h
serialP.h
serio.h
shm.h
shmem_fs.h
signal.h
skbuff.h	Merge git://git.infradead.org/hdrcleanup-2.6	2006-06-20 15:10:08 -07:00
slab.h	Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6	2006-05-24 09:22:21 +01:00
smb_fs_i.h
smb_fs_sb.h
smb_fs.h
smb_mount.h
smb.h
smbno.h
smp_lock.h
smp.h
snmp.h
socket.h
sockios.h
som.h
sonet.h
sonypi.h
sort.h
sound.h
soundcard.h
spinlock_api_smp.h
spinlock_api_up.h
spinlock_types_up.h
spinlock_types.h
spinlock_up.h
spinlock.h
stallion.h
stat.h
statfs.h
stddef.h
stop_machine.h
string.h
stringify.h
superhyway.h
suspend.h
swap.h	Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6	2006-05-24 09:22:21 +01:00
swapops.h
synclink.h
sys.h
syscalls.h	Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6	2006-05-24 09:22:21 +01:00
sysctl.h	[TCP]: Add tcp_slow_start_after_idle sysctl.	2006-06-17 21:30:53 -07:00
sysdev.h	[PATCH] Driver Core: Allow sysdev_class have attributes	2006-06-21 12:40:48 -07:00
sysfs.h
sysrq.h
sysv_fs.h
tcp.h	Merge git://git.infradead.org/hdrcleanup-2.6	2006-06-20 15:10:08 -07:00
telephony.h
termios.h
textsearch_fsm.h
textsearch.h
tfrc.h
thread_info.h
threads.h
ticable.h
time.h
timer.h
times.h
timex.h
tiocl.h
tipc_config.h
tipc.h
topology.h
toshiba.h
transport_class.h
trdevice.h
tty_driver.h
tty_flip.h
tty_ldisc.h
tty.h	[PATCH] TTY: return class device pointer from tty_register_device()	2006-06-21 12:40:47 -07:00
types.h
udf_fs_i.h
udf_fs_sb.h
udf_fs.h
udp.h
ufs_fs_i.h
ufs_fs_sb.h
ufs_fs.h	Remove unneeded inclusion of <linux/time.h> from <linux/ufs_fs.h>	2006-05-04 00:59:14 +01:00
uinput.h
uio.h
ultrasound.h
umem.h
un.h
unistd.h
usb_ch9.h
usb_gadget.h
usb_gadgetfs.h
usb_otg.h
usb_usual.h
usb.h	[PATCH] USB: convert usb class devices to real devices	2006-06-21 15:04:19 -07:00
usbdevice_fs.h
user.h
utime.h
uts.h
utsname.h
vermagic.h
vfs.h
via.h
video_decoder.h
video_encoder.h
videodev2.h	V4L/DVB (3774): Create V4L1 config options	2006-05-12 19:54:53 -03:00
videodev.h
videotext.h
vmalloc.h
vt_buffer.h
vt_kern.h	Merge git://git.infradead.org/hdrcleanup-2.6	2006-06-20 15:10:08 -07:00
vt.h
wait.h
wanrouter.h
watchdog.h
wavefront.h
wireless.h
workqueue.h
writeback.h
x25.h
xattr.h
xfrm.h	[IPSEC] xfrm: Abstract out encapsulation modes	2006-06-17 21:28:39 -07:00
yam.h
zconf.h
zftape.h
zlib.h
zorro_ids.h
zorro.h
zutil.h