Revision 24a70313969fc3fc440216b40babdb42564acff3 authored by Chris Mason on 21 November 2011, 14:39:11 UTC, committed by Chris Mason on 21 November 2011, 19:57:33 UTC
The log replay code only partially loads block groups, since the block group caching code is able to detect and deal with extents the logging code has pinned down. While the logging code is pinning down block groups, there is a bogus WARN_ON we're hitting if the code wasn't able to find an extent in the cache. This commit removes the warning because it can happen any time there isn't a valid free space cache for that block group. Signed-off-by: Chris Mason <chris.mason@oracle.com>
1 parent 4d479cf
ioprio.c
/*
* fs/ioprio.c
*
* Copyright (C) 2004 Jens Axboe <axboe@kernel.dk>
*
* Helper functions for setting/querying io priorities of processes. The
* system calls closely mimmick getpriority/setpriority, see the man page for
* those. The prio argument is a composite of prio class and prio data, where
* the data argument has meaning within that class. The standard scheduling
* classes have 8 distinct prio levels, with 0 being the highest prio and 7
* being the lowest.
*
* IOW, setting BE scheduling class with prio 2 is done ala:
*
* unsigned int prio = (IOPRIO_CLASS_BE << IOPRIO_CLASS_SHIFT) | 2;
*
* ioprio_set(PRIO_PROCESS, pid, prio);
*
* See also Documentation/block/ioprio.txt
*
*/
#include <linux/gfp.h>
#include <linux/kernel.h>
#include <linux/ioprio.h>
#include <linux/blkdev.h>
#include <linux/capability.h>
#include <linux/syscalls.h>
#include <linux/security.h>
#include <linux/pid_namespace.h>
int set_task_ioprio(struct task_struct *task, int ioprio)
{
int err;
struct io_context *ioc;
const struct cred *cred = current_cred(), *tcred;
rcu_read_lock();
tcred = __task_cred(task);
if (tcred->uid != cred->euid &&
tcred->uid != cred->uid && !capable(CAP_SYS_NICE)) {
rcu_read_unlock();
return -EPERM;
}
rcu_read_unlock();
err = security_task_setioprio(task, ioprio);
if (err)
return err;
task_lock(task);
do {
ioc = task->io_context;
/* see wmb() in current_io_context() */
smp_read_barrier_depends();
if (ioc)
break;
ioc = alloc_io_context(GFP_ATOMIC, -1);
if (!ioc) {
err = -ENOMEM;
break;
}
task->io_context = ioc;
} while (1);
if (!err) {
ioc->ioprio = ioprio;
ioc->ioprio_changed = 1;
}
task_unlock(task);
return err;
}
EXPORT_SYMBOL_GPL(set_task_ioprio);
SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio)
{
int class = IOPRIO_PRIO_CLASS(ioprio);
int data = IOPRIO_PRIO_DATA(ioprio);
struct task_struct *p, *g;
struct user_struct *user;
struct pid *pgrp;
int ret;
switch (class) {
case IOPRIO_CLASS_RT:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
/* fall through, rt has prio field too */
case IOPRIO_CLASS_BE:
if (data >= IOPRIO_BE_NR || data < 0)
return -EINVAL;
break;
case IOPRIO_CLASS_IDLE:
break;
case IOPRIO_CLASS_NONE:
if (data)
return -EINVAL;
break;
default:
return -EINVAL;
}
ret = -ESRCH;
rcu_read_lock();
switch (which) {
case IOPRIO_WHO_PROCESS:
if (!who)
p = current;
else
p = find_task_by_vpid(who);
if (p)
ret = set_task_ioprio(p, ioprio);
break;
case IOPRIO_WHO_PGRP:
if (!who)
pgrp = task_pgrp(current);
else
pgrp = find_vpid(who);
do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
ret = set_task_ioprio(p, ioprio);
if (ret)
break;
} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
break;
case IOPRIO_WHO_USER:
if (!who)
user = current_user();
else
user = find_user(who);
if (!user)
break;
do_each_thread(g, p) {
if (__task_cred(p)->uid != who)
continue;
ret = set_task_ioprio(p, ioprio);
if (ret)
goto free_uid;
} while_each_thread(g, p);
free_uid:
if (who)
free_uid(user);
break;
default:
ret = -EINVAL;
}
rcu_read_unlock();
return ret;
}
static int get_task_ioprio(struct task_struct *p)
{
int ret;
ret = security_task_getioprio(p);
if (ret)
goto out;
ret = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, IOPRIO_NORM);
if (p->io_context)
ret = p->io_context->ioprio;
out:
return ret;
}
int ioprio_best(unsigned short aprio, unsigned short bprio)
{
unsigned short aclass = IOPRIO_PRIO_CLASS(aprio);
unsigned short bclass = IOPRIO_PRIO_CLASS(bprio);
if (aclass == IOPRIO_CLASS_NONE)
aclass = IOPRIO_CLASS_BE;
if (bclass == IOPRIO_CLASS_NONE)
bclass = IOPRIO_CLASS_BE;
if (aclass == bclass)
return min(aprio, bprio);
if (aclass > bclass)
return bprio;
else
return aprio;
}
SYSCALL_DEFINE2(ioprio_get, int, which, int, who)
{
struct task_struct *g, *p;
struct user_struct *user;
struct pid *pgrp;
int ret = -ESRCH;
int tmpio;
rcu_read_lock();
switch (which) {
case IOPRIO_WHO_PROCESS:
if (!who)
p = current;
else
p = find_task_by_vpid(who);
if (p)
ret = get_task_ioprio(p);
break;
case IOPRIO_WHO_PGRP:
if (!who)
pgrp = task_pgrp(current);
else
pgrp = find_vpid(who);
do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
tmpio = get_task_ioprio(p);
if (tmpio < 0)
continue;
if (ret == -ESRCH)
ret = tmpio;
else
ret = ioprio_best(ret, tmpio);
} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
break;
case IOPRIO_WHO_USER:
if (!who)
user = current_user();
else
user = find_user(who);
if (!user)
break;
do_each_thread(g, p) {
if (__task_cred(p)->uid != user->uid)
continue;
tmpio = get_task_ioprio(p);
if (tmpio < 0)
continue;
if (ret == -ESRCH)
ret = tmpio;
else
ret = ioprio_best(ret, tmpio);
} while_each_thread(g, p);
if (who)
free_uid(user);
break;
default:
ret = -EINVAL;
}
rcu_read_unlock();
return ret;
}
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