Commit 6636f443 authored by Zhao Minmin's avatar Zhao Minmin Committed by Yang Yingliang
Browse files

ext4: report error to userspace by netlink 



hulk inclusion
category: feature
bugzilla: 34592
CVE: NA

-------------------------------------------------

Implement the ext3/ext4 file system error report.

This patch is used to implement abnormal alarm of ext3/ext4 filesystem.
You can archieve this by setting "FILESYSTEM_MONITOR" or "FILESYSTEM_ALARM"
on in configuration file. With this setting, alarm will be raised when
ext3/ext4 file system expection occurs.

Signed-off-by: default avatarZhao Minmin <zhaominmin1@huawei.com>
Reviewed-by: default avatarYi Zhang <yi.zhang@huawei.com>
Link: http://hulk.huawei.com/pipermail/kernel.openeuler/2016-March/009711.html


Signed-off-by: default avatarWang Hui <john.wanghui@huawei.com>
Signed-off-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>

[yebin: cherry-pick this patch from redhat-7.5, commit 13848b1856c1]

Signed-off-by: default avatarYe Bin <yebin10@huawei.com>
Reviewed-by: default avatarWenan Mao <maowenan@huawei.com>
Reviewed-by: default avatarYi Zhang <yi.zhang@huawei.com>
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
parent 9ca321d8

fs/ext4/ext4.h

+9 −0
Original line number Diff line number Diff line
@@ -54,6 +54,15 @@ 
#endif

#endif



#define NL_EXT4_ERROR_GROUP    1

#define EXT4_ERROR_MAGIC       0xAE32014U

struct ext4_err_msg {

	int magic;

	char s_id[32];

	unsigned long s_flags;

	int ext4_errno;

};



/*

 * The fourth extended filesystem constants/structures

 */

fs/ext4/super.c

+51 −0
Original line number Diff line number Diff line
@@ -54,6 +54,10 @@ 
#include "mballoc.h"

#include "fsmap.h"



#include <uapi/linux/netlink.h>

#include <net/sock.h>

#include <net/net_namespace.h>



#define CREATE_TRACE_POINTS

#include <trace/events/ext4.h>
@@ -84,6 +88,8 @@ static void ext4_unregister_li_request(struct super_block *sb); 
static void ext4_clear_request_list(void);

static struct inode *ext4_get_journal_inode(struct super_block *sb,

					    unsigned int journal_inum);

static void ext4_netlink_send_info(struct super_block *sb, int ext4_errno);

static struct sock *ext4nl;



/*

 * Lock ordering
@@ -438,6 +444,42 @@ static bool system_going_down(void) 
		|| system_state == SYSTEM_RESTART;

}



static void ext4_netlink_send_info(struct super_block *sb, int ext4_errno)

{

	int size;

	sk_buff_data_t old_tail;

	struct sk_buff *skb;

	struct nlmsghdr *nlh;

	struct ext4_err_msg *msg;



	if (ext4nl) {

		size = NLMSG_SPACE(sizeof(struct ext4_err_msg));

		skb = alloc_skb(size, GFP_ATOMIC);

		if (!skb) {

			printk(KERN_ERR "Cannot alloc skb!");

			return;

		}

		old_tail = skb->tail;

		nlh = nlmsg_put(skb, 0, 0, NLMSG_ERROR, size - sizeof(*nlh), 0);

		if (!nlh)

			goto nlmsg_failure;

		msg = (struct ext4_err_msg *)NLMSG_DATA(nlh);

		msg->magic = EXT4_ERROR_MAGIC;

		memcpy(msg->s_id, sb->s_id, sizeof(sb->s_id));

		msg->s_flags = sb->s_flags;

		msg->ext4_errno = ext4_errno;

		nlh->nlmsg_len = skb->tail - old_tail;

		NETLINK_CB(skb).portid = 0;

		NETLINK_CB(skb).dst_group = NL_EXT4_ERROR_GROUP;

		netlink_broadcast(ext4nl, skb, 0, NL_EXT4_ERROR_GROUP,

		 GFP_ATOMIC);

		return;

nlmsg_failure:

		if (skb)

			kfree_skb(skb);

	}

}



/* Deal with the reporting of failure conditions on a filesystem such as

 * inconsistencies detected or read IO failures.

 *
@@ -468,6 +510,9 @@ static void ext4_handle_error(struct super_block *sb) 
		if (journal)

			jbd2_journal_abort(journal, -EIO);

	}



	ext4_netlink_send_info(sb, 1);



	/*

	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we

	 * could panic during 'reboot -f' as the underlying device got already
@@ -699,6 +744,7 @@ void __ext4_abort(struct super_block *sb, const char *function, 
		if (EXT4_SB(sb)->s_journal)

			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);

		save_error_info(sb, function, line);

		ext4_netlink_send_info(sb, 2);

	}

	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {

		if (EXT4_SB(sb)->s_journal &&
@@ -6026,6 +6072,7 @@ wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ]; 
static int __init ext4_init_fs(void)

{

	int i, err;

	struct netlink_kernel_cfg cfg = {.groups = NL_EXT4_ERROR_GROUP,};



	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);

	ext4_li_info = NULL;
@@ -6065,6 +6112,9 @@ static int __init ext4_init_fs(void) 
	if (err)

		goto out;



	ext4nl = netlink_kernel_create(&init_net, NETLINK_FILESYSTEM, &cfg);

	if (!ext4nl)

		printk(KERN_ERR "EXT4-fs: Cannot create netlink socket.\n");

	return 0;

out:

	unregister_as_ext2();
@@ -6096,6 +6146,7 @@ static void __exit ext4_exit_fs(void) 
	ext4_exit_system_zone();

	ext4_exit_pageio();

	ext4_exit_es();

	netlink_kernel_release(ext4nl);

}



MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");

include/uapi/linux/netlink.h

+1 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 
#define NETLINK_RDMA		20

#define NETLINK_CRYPTO		21	/* Crypto layer */

#define NETLINK_SMC		22	/* SMC monitoring */

#define NETLINK_FILESYSTEM	28	/* filesystem alarm*/



#define NETLINK_INET_DIAG	NETLINK_SOCK_DIAG