Revision 289454ad26a2d752e04b07234a175feda9ec0f4e authored by Naohiro Aota on 05 January 2015, 16:01:03 UTC, committed by Chris Mason on 03 February 2015, 03:24:51 UTC
After submit_one_bio(), `bio' can go away. However submit_extent_page() leave `bio' referable if submit_one_bio() failed (e.g. -ENOMEM on OOM). It will cause invalid paging request when submit_extent_page() is called next time. I reproduced ENOMEM case with the following script (need CONFIG_FAIL_PAGE_ALLOC, and CONFIG_FAULT_INJECTION_DEBUG_FS). #!/bin/bash dmesgout=dmesg.txt start=100000 end=300000 step=1000 # btrfs options device=/dev/vdb1 directory=/mnt/btrfs # fault-injection options percent=100 times=3 mkdir -p $directory || exit 1 mount -o compress $device $directory || exit 1 rm -f $directory/file || exit 1 dd if=/dev/zero of=$directory/file bs=1M count=512 || exit 1 for interval in `seq $start $step $end`; do dmesg -C echo 1 > /proc/sys/vm/drop_caches sync export FAILCMD_TYPE=fail_page_alloc ./failcmd.sh -p $percent -t $times -i $interval \ --ignore-gfp-highmem=N --ignore-gfp-wait=N --min-order=0 \ -- \ cat $directory/file > /dev/null dmesg > ${dmesgout} if grep -q BUG: ${dmesgout}; then cat ${dmesgout} exit 1 fi done umount $directory exit 0 Signed-off-by: Naohiro Aota <naota@elisp.net> Tested-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
1 parent de554a4
procfs.c
/*
* Procfs support for lockd
*
* Copyright (c) 2014 Jeff Layton <jlayton@primarydata.com>
*/
#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/module.h>
#include <linux/nsproxy.h>
#include <net/net_namespace.h>
#include "netns.h"
#include "procfs.h"
/*
* We only allow strings that start with 'Y', 'y', or '1'.
*/
static ssize_t
nlm_end_grace_write(struct file *file, const char __user *buf, size_t size,
loff_t *pos)
{
char *data;
struct lockd_net *ln = net_generic(current->nsproxy->net_ns,
lockd_net_id);
if (size < 1)
return -EINVAL;
data = simple_transaction_get(file, buf, size);
if (IS_ERR(data))
return PTR_ERR(data);
switch(data[0]) {
case 'Y':
case 'y':
case '1':
locks_end_grace(&ln->lockd_manager);
break;
default:
return -EINVAL;
}
return size;
}
static ssize_t
nlm_end_grace_read(struct file *file, char __user *buf, size_t size,
loff_t *pos)
{
struct lockd_net *ln = net_generic(current->nsproxy->net_ns,
lockd_net_id);
char resp[3];
resp[0] = list_empty(&ln->lockd_manager.list) ? 'Y' : 'N';
resp[1] = '\n';
resp[2] = '\0';
return simple_read_from_buffer(buf, size, pos, resp, sizeof(resp));
}
static const struct file_operations lockd_end_grace_operations = {
.write = nlm_end_grace_write,
.read = nlm_end_grace_read,
.llseek = default_llseek,
.release = simple_transaction_release,
.owner = THIS_MODULE,
};
int __init
lockd_create_procfs(void)
{
struct proc_dir_entry *entry;
entry = proc_mkdir("fs/lockd", NULL);
if (!entry)
return -ENOMEM;
entry = proc_create("nlm_end_grace", S_IRUGO|S_IWUSR, entry,
&lockd_end_grace_operations);
if (!entry) {
remove_proc_entry("fs/lockd", NULL);
return -ENOMEM;
}
return 0;
}
void __exit
lockd_remove_procfs(void)
{
remove_proc_entry("fs/lockd/nlm_end_grace", NULL);
remove_proc_entry("fs/lockd", NULL);
}
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...