Commit 56fc37d9 authored by Anand Jain's avatar Anand Jain Committed by David Sterba
Browse files

btrfs: balance: print args during start and resume 



The information about balance arguments is important for system audit,
this patch prints the textual representation when balance starts or is
resumed.

Example command:

 $ btrfs balance start -f -mprofiles=raid1,convert=single,soft -dlimit=10..20,usage=50 /btrfs

Example kernel log output:

 BTRFS info (device sdb): balance: start -f -dusage=50,limit=10..20 -mconvert=single,soft,profiles=raid1 -sconvert=single,soft,profiles=raid1

Signed-off-by: default avatarAnand Jain <anand.jain@oracle.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
[ update changelog, simplify code ]
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent f89e09cf

fs/btrfs/volumes.c

+158 −3
Original line number Diff line number Diff line
@@ -3979,6 +3979,162 @@ static inline int validate_convert_profile(struct btrfs_balance_args *bctl_arg, 
		 (bctl_arg->target & ~allowed)));

}



/*

 * Fill @buf with textual description of balance filter flags @bargs, up to

 * @size_buf including the terminating null. The output may be trimmed if it

 * does not fit into the provided buffer.

 */

static void describe_balance_args(struct btrfs_balance_args *bargs, char *buf,

				 u32 size_buf)

{

	int ret;

	u32 size_bp = size_buf;

	char *bp = buf;

	u64 flags = bargs->flags;

	char tmp_buf[128] = {'\0'};



	if (!flags)

		return;



#define CHECK_APPEND_NOARG(a)						\

	do {								\

		ret = snprintf(bp, size_bp, (a));			\

		if (ret < 0 || ret >= size_bp)				\

			goto out_overflow;				\

		size_bp -= ret;						\

		bp += ret;						\

	} while (0)



#define CHECK_APPEND_1ARG(a, v1)					\

	do {								\

		ret = snprintf(bp, size_bp, (a), (v1));			\

		if (ret < 0 || ret >= size_bp)				\

			goto out_overflow;				\

		size_bp -= ret;						\

		bp += ret;						\

	} while (0)



#define CHECK_APPEND_2ARG(a, v1, v2)					\

	do {								\

		ret = snprintf(bp, size_bp, (a), (v1), (v2));		\

		if (ret < 0 || ret >= size_bp)				\

			goto out_overflow;				\

		size_bp -= ret;						\

		bp += ret;						\

	} while (0)



	if (flags & BTRFS_BALANCE_ARGS_CONVERT) {

		int index = btrfs_bg_flags_to_raid_index(bargs->target);



		CHECK_APPEND_1ARG("convert=%s,", get_raid_name(index));

	}



	if (flags & BTRFS_BALANCE_ARGS_SOFT)

		CHECK_APPEND_NOARG("soft,");



	if (flags & BTRFS_BALANCE_ARGS_PROFILES) {

		btrfs_describe_block_groups(bargs->profiles, tmp_buf,

					    sizeof(tmp_buf));

		CHECK_APPEND_1ARG("profiles=%s,", tmp_buf);

	}



	if (flags & BTRFS_BALANCE_ARGS_USAGE)

		CHECK_APPEND_1ARG("usage=%llu,", bargs->usage);



	if (flags & BTRFS_BALANCE_ARGS_USAGE_RANGE)

		CHECK_APPEND_2ARG("usage=%u..%u,",

				  bargs->usage_min, bargs->usage_max);



	if (flags & BTRFS_BALANCE_ARGS_DEVID)

		CHECK_APPEND_1ARG("devid=%llu,", bargs->devid);



	if (flags & BTRFS_BALANCE_ARGS_DRANGE)

		CHECK_APPEND_2ARG("drange=%llu..%llu,",

				  bargs->pstart, bargs->pend);



	if (flags & BTRFS_BALANCE_ARGS_VRANGE)

		CHECK_APPEND_2ARG("vrange=%llu..%llu,",

				  bargs->vstart, bargs->vend);



	if (flags & BTRFS_BALANCE_ARGS_LIMIT)

		CHECK_APPEND_1ARG("limit=%llu,", bargs->limit);



	if (flags & BTRFS_BALANCE_ARGS_LIMIT_RANGE)

		CHECK_APPEND_2ARG("limit=%u..%u,",

				bargs->limit_min, bargs->limit_max);



	if (flags & BTRFS_BALANCE_ARGS_STRIPES_RANGE)

		CHECK_APPEND_2ARG("stripes=%u..%u,",

				  bargs->stripes_min, bargs->stripes_max);



#undef CHECK_APPEND_2ARG

#undef CHECK_APPEND_1ARG

#undef CHECK_APPEND_NOARG



out_overflow:



	if (size_bp < size_buf)

		buf[size_buf - size_bp - 1] = '\0'; /* remove last , */

	else

		buf[0] = '\0';

}



static void describe_balance_start_or_resume(struct btrfs_fs_info *fs_info)

{

	u32 size_buf = 1024;

	char tmp_buf[192] = {'\0'};

	char *buf;

	char *bp;

	u32 size_bp = size_buf;

	int ret;

	struct btrfs_balance_control *bctl = fs_info->balance_ctl;



	buf = kzalloc(size_buf, GFP_KERNEL);

	if (!buf)

		return;



	bp = buf;



#define CHECK_APPEND_1ARG(a, v1)					\

	do {								\

		ret = snprintf(bp, size_bp, (a), (v1));			\

		if (ret < 0 || ret >= size_bp)				\

			goto out_overflow;				\

		size_bp -= ret;						\

		bp += ret;						\

	} while (0)



	if (bctl->flags & BTRFS_BALANCE_FORCE)

		CHECK_APPEND_1ARG("%s", "-f ");



	if (bctl->flags & BTRFS_BALANCE_DATA) {

		describe_balance_args(&bctl->data, tmp_buf, sizeof(tmp_buf));

		CHECK_APPEND_1ARG("-d%s ", tmp_buf);

	}



	if (bctl->flags & BTRFS_BALANCE_METADATA) {

		describe_balance_args(&bctl->meta, tmp_buf, sizeof(tmp_buf));

		CHECK_APPEND_1ARG("-m%s ", tmp_buf);

	}



	if (bctl->flags & BTRFS_BALANCE_SYSTEM) {

		describe_balance_args(&bctl->sys, tmp_buf, sizeof(tmp_buf));

		CHECK_APPEND_1ARG("-s%s ", tmp_buf);

	}



#undef CHECK_APPEND_1ARG



out_overflow:



	if (size_bp < size_buf)

		buf[size_buf - size_bp - 1] = '\0'; /* remove last " " */

	btrfs_info(fs_info, "balance: %s %s",

		   (bctl->flags & BTRFS_BALANCE_RESUME) ?

		   "resume" : "start", buf);



	kfree(buf);

}



/*

 * Should be called with balance mutexe held

 */
@@ -4125,6 +4281,7 @@ int btrfs_balance(struct btrfs_fs_info *fs_info, 


	ASSERT(!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));

	set_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags);

	describe_balance_start_or_resume(fs_info);

	mutex_unlock(&fs_info->balance_mutex);



	ret = __btrfs_balance(fs_info);
@@ -4162,10 +4319,8 @@ static int balance_kthread(void *data) 
	int ret = 0;



	mutex_lock(&fs_info->balance_mutex);

	if (fs_info->balance_ctl) {

		btrfs_info(fs_info, "balance: resuming");

	if (fs_info->balance_ctl)

		ret = btrfs_balance(fs_info, fs_info->balance_ctl, NULL);

	}

	mutex_unlock(&fs_info->balance_mutex);



	return ret;

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