linux/kernel
Eric Dumazet 7e360c38ab fs: allow for more than 2^31 files
Andrew,

Could you please review this patch, you probably are the right guy to
take it, because it crosses fs and net trees.

Note : /proc/sys/fs/file-nr is a read-only file, so this patch doesnt
depend on previous patch (sysctl: fix min/max handling in
__do_proc_doulongvec_minmax())

Thanks !

[PATCH V4] fs: allow for more than 2^31 files

Robin Holt tried to boot a 16TB system and found af_unix was overflowing
a 32bit value :

<quote>

We were seeing a failure which prevented boot.  The kernel was incapable
of creating either a named pipe or unix domain socket.  This comes down
to a common kernel function called unix_create1() which does:

        atomic_inc(&unix_nr_socks);
        if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
                goto out;

The function get_max_files() is a simple return of files_stat.max_files.
files_stat.max_files is a signed integer and is computed in
fs/file_table.c's files_init().

        n = (mempages * (PAGE_SIZE / 1024)) / 10;
        files_stat.max_files = n;

In our case, mempages (total_ram_pages) is approx 3,758,096,384
(0xe0000000).  That leaves max_files at approximately 1,503,238,553.
This causes 2 * get_max_files() to integer overflow.

</quote>

Fix is to let /proc/sys/fs/file-nr & /proc/sys/fs/file-max use long
integers, and change af_unix to use an atomic_long_t instead of
atomic_t.

get_max_files() is changed to return an unsigned long.
get_nr_files() is changed to return a long.

unix_nr_socks is changed from atomic_t to atomic_long_t, while not
strictly needed to address Robin problem.

Before patch (on a 64bit kernel) :
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
-18446744071562067968

After patch:
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
2147483648
# cat /proc/sys/fs/file-nr
704     0       2147483648

Reported-by: Robin Holt <holt@sgi.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David Miller <davem@davemloft.net>
Reviewed-by: Robin Holt <holt@sgi.com>
Tested-by: Robin Holt <holt@sgi.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:18:20 -04:00
..
debug kdb,debug_core: adjust master cpu switch logic against new debug_core locking 2010-10-22 15:34:13 -05:00
gcov llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
irq genirq: Fix CONFIG_GENIRQ_NO_DEPRECATED=y build 2010-10-12 21:59:55 +02:00
power PM: Introduce library for device-specific OPPs (v7) 2010-10-17 01:57:50 +02:00
time ntp: Clamp PLL update interval 2010-09-09 20:48:37 +02:00
trace Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-10-24 13:41:39 -07:00
.gitignore
acct.c pass a struct path to vfs_statfs 2010-08-09 16:48:42 -04:00
async.c async: use workqueue for worker pool 2010-07-14 11:29:46 +02:00
audit_tree.c fanotify: use both marks when possible 2010-07-28 10:18:55 -04:00
audit_watch.c Revert "fsnotify: store struct file not struct path" 2010-08-12 14:23:04 -07:00
audit.c Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify 2010-08-10 11:39:13 -07:00
audit.h Audit: split audit watch Kconfig 2010-07-28 09:58:19 -04:00
auditfilter.c audit: do not get and put just to free a watch 2010-07-28 09:58:17 -04:00
auditsc.c vfs: add helpers to get root and pwd 2010-08-11 00:28:20 -04:00
backtracetest.c
bounds.c
capability.c sched: Remove remaining USER_SCHED code 2010-04-02 20:12:00 +02:00
cgroup_freezer.c Freezer / cgroup freezer: Update stale locking comments 2010-05-10 23:18:47 +02:00
cgroup.c Merge branch 'vfs' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl 2010-10-22 10:52:01 -07:00
compat.c compat: Make compat_alloc_user_space() incorporate the access_ok() 2010-09-14 16:08:45 -07:00
configs.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
cpu.c sched: adjust when cpu_active and cpuset configurations are updated during cpu on/offlining 2010-06-08 21:40:36 +02:00
cpuset.c security: remove unused parameter from security_task_setscheduler() 2010-10-21 10:12:44 +11:00
cred.c Add a dummy printk function for the maintenance of unused printks 2010-08-12 09:51:35 -07:00
delayacct.c
dma.c
elfcore.c elf coredump: add extended numbering support 2010-03-06 11:26:46 -08:00
exec_domain.c sys_personality: remove the bogus checks in sys_personality()->__set_personality() path 2010-08-09 20:45:05 -07:00
exit.c perf: Fix up delayed_put_task_struct() 2010-09-09 21:07:09 +02:00
extable.c
fork.c rmap: fix walk during fork 2010-09-22 17:22:39 -07:00
freezer.c
futex_compat.c futex: Change 3rd arg of fetch_robust_entry() to unsigned int* 2010-09-18 12:19:21 +02:00
futex.c Merge branch 'futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 14:06:17 -07:00
groups.c kernel/groups.c: fix integer overflow in groups_search 2010-09-09 18:57:24 -07:00
hrtimer.c hrtimer: Preserve timer state in remove_hrtimer() 2010-10-14 13:29:59 +02:00
hung_task.c lockup detector: Fix grammar by adding a missing "to" in the comments 2010-08-17 09:11:52 +02:00
hw_breakpoint.c perf, hw_breakpoint: Fix crash in hw_breakpoint creation 2010-10-18 19:58:55 +02:00
irq_work.c irq_work: Add generic hardirq context callbacks 2010-10-18 19:58:50 +02:00
itimer.c
jump_label.c jump label: Add jump_label_text_reserved() to reserve jump points 2010-09-22 16:30:46 -04:00
kallsyms.c kdb: core for kgdb back end (2 of 2) 2010-05-20 21:04:21 -05:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c kexec: return -EFAULT on copy_to_user() failures 2010-08-11 08:59:22 -07:00
kfifo.c kfifo: fix scatterlist usage 2010-10-01 10:50:58 -07:00
kmod.c Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
kprobes.c Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl 2010-10-22 10:52:56 -07:00
ksysfs.c sysfs: add struct file* to bin_attr callbacks 2010-05-21 09:37:31 -07:00
kthread.c kthread: implement kthread_data() 2010-06-29 10:07:09 +02:00
latencytop.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
lockdep_internals.h lockdep: No need to disable preemption in debug atomic ops 2010-05-04 05:38:16 +02:00
lockdep_proc.c lockstat: Make lockstat counting per cpu 2010-04-06 00:15:37 +02:00
lockdep_states.h
lockdep.c lockdep: Check the depth of subclass 2010-10-18 18:44:26 +02:00
Makefile Merge branch 'core-memblock-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 18:52:11 -07:00
module.c Merge commit 'v2.6.36-rc7' into perf/core 2010-10-08 10:46:27 +02:00
mutex-debug.c
mutex-debug.h
mutex.c mutex: Fix annotations to include it in kernel-locking docbook 2010-09-03 08:19:51 +02:00
mutex.h
notifier.c sched: Use lockdep-based checking on rcu_dereference() 2010-02-25 10:34:26 +01:00
ns_cgroup.c
nsproxy.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
padata.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2010-08-04 15:23:14 -07:00
panic.c lib/bug.c: add oops end marker to WARN implementation 2010-08-11 08:59:22 -07:00
params.c param: locking for kernel parameters 2010-08-11 23:04:20 +09:30
perf_event.c Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 12:54:49 -07:00
pid_namespace.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
pid.c Add RCU check for find_task_by_vpid(). 2010-08-19 17:18:02 -07:00
pm_qos_params.c Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-10-24 13:41:39 -07:00
posix-cpu-timers.c Merge branch 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linux 2010-08-10 12:07:51 -07:00
posix-timers.c posix_timer: Move copy_to_user(created_timer_id) down in timer_create() 2010-07-23 15:08:12 +02:00
printk.c printk: Make console_sem a semaphore not a pseudo mutex 2010-10-12 17:36:10 +02:00
profile.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
ptrace.c ptrace: optimize exit_ptrace() for the likely case 2010-08-11 08:59:19 -07:00
range.c kernel/range: remove unused definition of ARRAY_SIZE() 2010-08-09 20:45:06 -07:00
rcupdate.c Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu into core/rcu 2010-10-07 09:43:11 +02:00
rcutiny_plugin.h rcu: performance fixes to TINY_PREEMPT_RCU callback checking 2010-08-27 10:51:17 -07:00
rcutiny.c rcu: Add a TINY_PREEMPT_RCU 2010-08-20 08:55:00 -07:00
rcutorture.c rcu: fix sparse errors in rcutorture.c 2010-09-23 09:16:42 -07:00
rcutree_plugin.h rcu: fix _oddness handling of verbose stall warnings 2010-09-02 16:15:30 -07:00
rcutree_trace.c rcu: Add tracing data to support queueing models 2010-09-23 09:16:53 -07:00
rcutree.c rcu: using ACCESS_ONCE() to observe the jiffies_stall/rnp->qsmask value 2010-10-07 10:41:06 -07:00
rcutree.h rcu: Add tracing data to support queueing models 2010-09-23 09:16:53 -07:00
relay.c kernel/: convert cpu notifier to return encapsulate errno value 2010-05-27 09:12:48 -07:00
res_counter.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
resource.c resource: shared I/O region support 2010-05-11 12:01:10 -07:00
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c rtmutex-tester: make it build without BKL 2010-10-19 11:29:56 +02:00
rtmutex.c
rtmutex.h
rwsem.c
sched_clock.c sched_clock: Add local_clock() API and improve documentation 2010-06-09 10:34:49 +02:00
sched_cpupri.c sched: No need for bootmem special cases 2010-07-17 12:06:22 +02:00
sched_cpupri.h sched: No need for bootmem special cases 2010-07-17 12:06:22 +02:00
sched_debug.c sched: Use correct macro to display sched_child_runs_first in /proc/sched_debug 2010-07-21 21:46:12 +02:00
sched_fair.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 12:55:43 -07:00
sched_features.h sched: Remove irq time from available CPU power 2010-10-18 20:52:27 +02:00
sched_idletask.c sched: Cure load average vs NO_HZ woes 2010-04-23 11:02:02 +02:00
sched_rt.c sched: Do not account irq time to current task 2010-10-18 20:52:26 +02:00
sched_stats.h sched: Remove the obsolete exit_state/signal hacks 2010-06-18 10:46:56 +02:00
sched_stoptask.c sched: Create special class for stop/migrate work 2010-10-18 18:41:58 +02:00
sched.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 12:55:43 -07:00
seccomp.c
semaphore.c
signal.c HWPOISON: Copy si_addr_lsb to user 2010-10-07 09:41:25 +02:00
smp.c generic-ipi: Fix deadlock in __smp_call_function_single 2010-09-10 16:48:40 +02:00
softirq.c Merge branches 'softirq-for-linus', 'x86-debug-for-linus', 'x86-numa-for-linus', 'x86-quirks-for-linus', 'x86-setup-for-linus', 'x86-uv-for-linus' and 'x86-vm86-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-23 08:25:36 -07:00
spinlock.c
srcu.c kernel: Remove undead ifdef CONFIG_DEBUG_LOCK_ALLOC 2010-09-23 09:14:51 -07:00
stacktrace.c
stop_machine.c sched: Create special class for stop/migrate work 2010-10-18 18:41:58 +02:00
sys_ni.c powerpc: define a compat_sys_recv cond_syscall 2010-09-23 17:03:55 +10:00
sys.c pid: make setpgid() system call use RCU read-side critical section 2010-08-31 17:00:18 -07:00
sysctl_binary.c sysctl: don't use own implementation of hex_to_bin() 2010-05-25 08:07:05 -07:00
sysctl_check.c sysctl: min/max bounds are optional 2010-10-15 14:42:24 -07:00
sysctl.c fs: allow for more than 2^31 files 2010-10-25 21:18:20 -04:00
taskstats.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
test_kprobes.c kprobes: Fix selftest to clear flags field for reusing probes 2010-10-14 08:55:27 +02:00
time.c time: Kill off CONFIG_GENERIC_TIME 2010-07-27 12:40:54 +02:00
timeconst.pl
timer.c irq_work: Add generic hardirq context callbacks 2010-10-18 19:58:50 +02:00
tracepoint.c jump_label: Use more consistent naming 2010-10-18 19:58:56 +02:00
tsacct.c mm: clean up mm_counter 2010-03-06 11:26:23 -08:00
uid16.c
up.c
user_namespace.c user_ns: Introduce user_nsmap_uid and user_ns_map_gid. 2010-06-16 14:55:34 -07:00
user-return-notifier.c
user.c sched: Remove a stale comment 2010-05-10 08:48:39 +02:00
utsname_sysctl.c
utsname.c
wait.c
watchdog.c Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 12:54:49 -07:00
workqueue_sched.h workqueue: implement concurrency managed dynamic worker pool 2010-06-29 10:07:14 +02:00
workqueue.c workqueue: remove in_workqueue_context() 2010-10-19 11:28:15 +02:00