1 // SPDX-License-Identifier: GPL-2.0
17 	csum = ext4_chksum(sbi, sbi->s_csum_seed, (char *)mmp, offset);  in ext4_mmp_csum()
27 	return mmp->mmp_checksum == ext4_mmp_csum(sb, mmp);  in ext4_mmp_csum_verify()
35 	mmp->mmp_checksum = ext4_mmp_csum(sb, mmp);  in ext4_mmp_csum_set()
39  * Write the MMP block using REQ_SYNC to try to get the block on-disk
44 	struct mmp_struct *mmp = (struct mmp_struct *)(bh->b_data);  in write_mmp_block()
53 	bh->b_end_io = end_buffer_write_sync;  in write_mmp_block()
59 		return -EIO;  in write_mmp_block()
83 			ret = -ENOMEM;  in read_mmp_block()
93 	mmp = (struct mmp_struct *)((*bh)->b_data);  in read_mmp_block()
94 	if (le32_to_cpu(mmp->mmp_magic) != EXT4_MMP_MAGIC) {  in read_mmp_block()
95 		ret = -EFSCORRUPTED;  in read_mmp_block()
99 		ret = -EFSBADCRC;  in read_mmp_block()
119 …      "MMP failure info: last update time: %llu, last update node: %.*s, last update device: %.*s",  in __dump_mmp_msg()
120 		       (unsigned long long)le64_to_cpu(mmp->mmp_time),  in __dump_mmp_msg()
121 		       (int)sizeof(mmp->mmp_nodename), mmp->mmp_nodename,  in __dump_mmp_msg()
122 		       (int)sizeof(mmp->mmp_bdevname), mmp->mmp_bdevname);  in __dump_mmp_msg()
126  * kmmpd will update the MMP sequence every s_mmp_update_interval seconds
131 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;  in kmmpd()
132 	struct buffer_head *bh = EXT4_SB(sb)->s_mmp_bh;  in kmmpd()
137 	int mmp_update_interval = le16_to_cpu(es->s_mmp_update_interval);  in kmmpd()
143 	mmp_block = le64_to_cpu(es->s_mmp_block);  in kmmpd()
144 	mmp = (struct mmp_struct *)(bh->b_data);  in kmmpd()
145 	mmp->mmp_time = cpu_to_le64(ktime_get_real_seconds());  in kmmpd()
152 	mmp->mmp_check_interval = cpu_to_le16(mmp_check_interval);  in kmmpd()
154 	memcpy(mmp->mmp_nodename, init_utsname()->nodename,  in kmmpd()
155 	       sizeof(mmp->mmp_nodename));  in kmmpd()
166 		mmp->mmp_seq = cpu_to_le32(seq);  in kmmpd()
167 		mmp->mmp_time = cpu_to_le64(ktime_get_real_seconds());  in kmmpd()
177 				ext4_error_err(sb, -retval,  in kmmpd()
183 		diff = jiffies - last_update_time;  in kmmpd()
186 						       HZ - diff);  in kmmpd()
193 		diff = jiffies - last_update_time;  in kmmpd()
200 				ext4_error_err(sb, -retval,  in kmmpd()
206 			mmp_check = (struct mmp_struct *)(bh_check->b_data);  in kmmpd()
207 			if (mmp->mmp_seq != mmp_check->mmp_seq ||  in kmmpd()
208 			    memcmp(mmp->mmp_nodename, mmp_check->mmp_nodename,  in kmmpd()
209 				   sizeof(mmp->mmp_nodename))) {  in kmmpd()
216 				retval = -EBUSY;  in kmmpd()
229 		mmp->mmp_check_interval = cpu_to_le16(mmp_check_interval);  in kmmpd()
235 	mmp->mmp_seq = cpu_to_le32(EXT4_MMP_SEQ_CLEAN);  in kmmpd()
236 	mmp->mmp_time = cpu_to_le64(ktime_get_real_seconds());  in kmmpd()
252 	if (sbi->s_mmp_tsk) {  in ext4_stop_mmpd()
253 		kthread_stop(sbi->s_mmp_tsk);  in ext4_stop_mmpd()
254 		brelse(sbi->s_mmp_bh);  in ext4_stop_mmpd()
255 		sbi->s_mmp_tsk = NULL;  in ext4_stop_mmpd()
280 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;  in ext4_multi_mount_protect()
284 	unsigned int mmp_check_interval = le16_to_cpu(es->s_mmp_update_interval);  in ext4_multi_mount_protect()
288 	if (mmp_block < le32_to_cpu(es->s_first_data_block) ||  in ext4_multi_mount_protect()
298 	mmp = (struct mmp_struct *)(bh->b_data);  in ext4_multi_mount_protect()
307 	if (le16_to_cpu(mmp->mmp_check_interval) > mmp_check_interval)  in ext4_multi_mount_protect()
308 		mmp_check_interval = le16_to_cpu(mmp->mmp_check_interval);  in ext4_multi_mount_protect()
310 	seq = le32_to_cpu(mmp->mmp_seq);  in ext4_multi_mount_protect()
322 	/* Print MMP interval if more than 20 secs. */  in ext4_multi_mount_protect()
324 		ext4_warning(sb, "MMP interval %u higher than expected, please"  in ext4_multi_mount_protect()
335 	mmp = (struct mmp_struct *)(bh->b_data);  in ext4_multi_mount_protect()
336 	if (seq != le32_to_cpu(mmp->mmp_seq)) {  in ext4_multi_mount_protect()
347 	mmp->mmp_seq = cpu_to_le32(seq);  in ext4_multi_mount_protect()
354 	 * wait for MMP interval and check mmp_seq.  in ext4_multi_mount_protect()
364 	mmp = (struct mmp_struct *)(bh->b_data);  in ext4_multi_mount_protect()
365 	if (seq != le32_to_cpu(mmp->mmp_seq)) {  in ext4_multi_mount_protect()
371 	EXT4_SB(sb)->s_mmp_bh = bh;  in ext4_multi_mount_protect()
373 	BUILD_BUG_ON(sizeof(mmp->mmp_bdevname) < BDEVNAME_SIZE);  in ext4_multi_mount_protect()
374 	snprintf(mmp->mmp_bdevname, sizeof(mmp->mmp_bdevname),  in ext4_multi_mount_protect()
375 		 "%pg", bh->b_bdev);  in ext4_multi_mount_protect()
378 	 * Start a kernel thread to update the MMP block periodically.  in ext4_multi_mount_protect()
380 	EXT4_SB(sb)->s_mmp_tsk = kthread_run(kmmpd, sb, "kmmpd-%.*s",  in ext4_multi_mount_protect()
381 					     (int)sizeof(mmp->mmp_bdevname),  in ext4_multi_mount_protect()
382 					     mmp->mmp_bdevname);  in ext4_multi_mount_protect()
383 	if (IS_ERR(EXT4_SB(sb)->s_mmp_tsk)) {  in ext4_multi_mount_protect()
384 		EXT4_SB(sb)->s_mmp_tsk = NULL;  in ext4_multi_mount_protect()
386 			     sb->s_id);  in ext4_multi_mount_protect()