Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3) #include <linux/random.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4) #include <linux/buffer_head.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5) #include <linux/utsname.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) #include <linux/kthread.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include "ext4.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) /* Checksumming functions */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) static __le32 ext4_mmp_csum(struct super_block *sb, struct mmp_struct *mmp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) 	struct ext4_sb_info *sbi = EXT4_SB(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) 	int offset = offsetof(struct mmp_struct, mmp_checksum);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) 	__u32 csum;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) 	csum = ext4_chksum(sbi, sbi->s_csum_seed, (char *)mmp, offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 	return cpu_to_le32(csum);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) static int ext4_mmp_csum_verify(struct super_block *sb, struct mmp_struct *mmp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 	if (!ext4_has_metadata_csum(sb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 		return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 	return mmp->mmp_checksum == ext4_mmp_csum(sb, mmp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) static void ext4_mmp_csum_set(struct super_block *sb, struct mmp_struct *mmp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 	if (!ext4_has_metadata_csum(sb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 	mmp->mmp_checksum = ext4_mmp_csum(sb, mmp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39)  * Write the MMP block using REQ_SYNC to try to get the block on-disk
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40)  * faster.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) static int write_mmp_block(struct super_block *sb, struct buffer_head *bh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	struct mmp_struct *mmp = (struct mmp_struct *)(bh->b_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 	 * We protect against freezing so that we don't create dirty buffers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 	 * on frozen filesystem.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 	sb_start_write(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	ext4_mmp_csum_set(sb, mmp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 	lock_buffer(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	bh->b_end_io = end_buffer_write_sync;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	get_bh(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	submit_bh(REQ_OP_WRITE, REQ_SYNC | REQ_META | REQ_PRIO, bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	wait_on_buffer(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	sb_end_write(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	if (unlikely(!buffer_uptodate(bh)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 		return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65)  * Read the MMP block. It _must_ be read from disk and hence we clear the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66)  * uptodate flag on the buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) static int read_mmp_block(struct super_block *sb, struct buffer_head **bh,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 			  ext4_fsblk_t mmp_block)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	struct mmp_struct *mmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	if (*bh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 		clear_buffer_uptodate(*bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	/* This would be sb_bread(sb, mmp_block), except we need to be sure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	 * that the MD RAID device cache has been bypassed, and that the read
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	 * is not blocked in the elevator. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	if (!*bh) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 		*bh = sb_getblk(sb, mmp_block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 		if (!*bh) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 			ret = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 			goto warn_exit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	lock_buffer(*bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	ret = ext4_read_bh(*bh, REQ_META | REQ_PRIO, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 	if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 		goto warn_exit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 	mmp = (struct mmp_struct *)((*bh)->b_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	if (le32_to_cpu(mmp->mmp_magic) != EXT4_MMP_MAGIC) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 		ret = -EFSCORRUPTED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 		goto warn_exit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 	if (!ext4_mmp_csum_verify(sb, mmp)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 		ret = -EFSBADCRC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 		goto warn_exit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) warn_exit:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	brelse(*bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	*bh = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	ext4_warning(sb, "Error %d while reading MMP block %llu",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 		     ret, mmp_block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)  * Dump as much information as possible to help the admin.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) void __dump_mmp_msg(struct super_block *sb, struct mmp_struct *mmp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 		    const char *function, unsigned int line, const char *msg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	__ext4_warning(sb, function, line, "%s", msg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 	__ext4_warning(sb, function, line,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 		       "MMP failure info: last update time: %llu, last update node: %.*s, last update device: %.*s",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 		       (unsigned long long)le64_to_cpu(mmp->mmp_time),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 		       (int)sizeof(mmp->mmp_nodename), mmp->mmp_nodename,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 		       (int)sizeof(mmp->mmp_bdevname), mmp->mmp_bdevname);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)  * kmmpd will update the MMP sequence every s_mmp_update_interval seconds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) static int kmmpd(void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	struct super_block *sb = (struct super_block *) data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	struct buffer_head *bh = EXT4_SB(sb)->s_mmp_bh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	struct mmp_struct *mmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	ext4_fsblk_t mmp_block;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	u32 seq = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	unsigned long failed_writes = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	int mmp_update_interval = le16_to_cpu(es->s_mmp_update_interval);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 	unsigned mmp_check_interval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	unsigned long last_update_time;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	unsigned long diff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	int retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	mmp_block = le64_to_cpu(es->s_mmp_block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	mmp = (struct mmp_struct *)(bh->b_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	mmp->mmp_time = cpu_to_le64(ktime_get_real_seconds());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	 * Start with the higher mmp_check_interval and reduce it if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	 * the MMP block is being updated on time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 	mmp_check_interval = max(EXT4_MMP_CHECK_MULT * mmp_update_interval,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 				 EXT4_MMP_MIN_CHECK_INTERVAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	mmp->mmp_check_interval = cpu_to_le16(mmp_check_interval);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	BUILD_BUG_ON(sizeof(mmp->mmp_bdevname) < BDEVNAME_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	bdevname(bh->b_bdev, mmp->mmp_bdevname);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	memcpy(mmp->mmp_nodename, init_utsname()->nodename,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	       sizeof(mmp->mmp_nodename));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	while (!kthread_should_stop() && !sb_rdonly(sb)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 		if (!ext4_has_feature_mmp(sb)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 			ext4_warning(sb, "kmmpd being stopped since MMP feature"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 				     " has been disabled.");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 			goto wait_to_exit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 		if (++seq > EXT4_MMP_SEQ_MAX)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 			seq = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 		mmp->mmp_seq = cpu_to_le32(seq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 		mmp->mmp_time = cpu_to_le64(ktime_get_real_seconds());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 		last_update_time = jiffies;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 		retval = write_mmp_block(sb, bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 		 * Don't spew too many error messages. Print one every
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 		 * (s_mmp_update_interval * 60) seconds.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 		if (retval) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 			if ((failed_writes % 60) == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 				ext4_error_err(sb, -retval,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 					       "Error writing to MMP block");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 			failed_writes++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 		diff = jiffies - last_update_time;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 		if (diff < mmp_update_interval * HZ)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 			schedule_timeout_interruptible(mmp_update_interval *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 						       HZ - diff);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 		 * We need to make sure that more than mmp_check_interval
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 		 * seconds have not passed since writing. If that has happened
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 		 * we need to check if the MMP block is as we left it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 		diff = jiffies - last_update_time;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 		if (diff > mmp_check_interval * HZ) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 			struct buffer_head *bh_check = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 			struct mmp_struct *mmp_check;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 			retval = read_mmp_block(sb, &bh_check, mmp_block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 			if (retval) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 				ext4_error_err(sb, -retval,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 					       "error reading MMP data: %d",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 					       retval);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 				goto wait_to_exit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 			mmp_check = (struct mmp_struct *)(bh_check->b_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 			if (mmp->mmp_seq != mmp_check->mmp_seq ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 			    memcmp(mmp->mmp_nodename, mmp_check->mmp_nodename,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 				   sizeof(mmp->mmp_nodename))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 				dump_mmp_msg(sb, mmp_check,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 					     "Error while updating MMP info. "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 					     "The filesystem seems to have been"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 					     " multiply mounted.");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 				ext4_error_err(sb, EBUSY, "abort");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 				put_bh(bh_check);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 				retval = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 				goto wait_to_exit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 			put_bh(bh_check);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 		 /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 		 * Adjust the mmp_check_interval depending on how much time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 		 * it took for the MMP block to be written.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 		mmp_check_interval = max(min(EXT4_MMP_CHECK_MULT * diff / HZ,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 					     EXT4_MMP_MAX_CHECK_INTERVAL),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 					 EXT4_MMP_MIN_CHECK_INTERVAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 		mmp->mmp_check_interval = cpu_to_le16(mmp_check_interval);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 	 * Unmount seems to be clean.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 	mmp->mmp_seq = cpu_to_le32(EXT4_MMP_SEQ_CLEAN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 	mmp->mmp_time = cpu_to_le64(ktime_get_real_seconds());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 	retval = write_mmp_block(sb, bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) wait_to_exit:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 	while (!kthread_should_stop()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 		set_current_state(TASK_INTERRUPTIBLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 		if (!kthread_should_stop())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 			schedule();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 	set_current_state(TASK_RUNNING);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 	return retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) void ext4_stop_mmpd(struct ext4_sb_info *sbi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 	if (sbi->s_mmp_tsk) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 		kthread_stop(sbi->s_mmp_tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 		brelse(sbi->s_mmp_bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 		sbi->s_mmp_tsk = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262)  * Get a random new sequence number but make sure it is not greater than
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263)  * EXT4_MMP_SEQ_MAX.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) static unsigned int mmp_new_seq(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 	u32 new_seq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 	do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 		new_seq = prandom_u32();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 	} while (new_seq > EXT4_MMP_SEQ_MAX);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 	return new_seq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277)  * Protect the filesystem from being mounted more than once.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) int ext4_multi_mount_protect(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 				    ext4_fsblk_t mmp_block)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 	struct buffer_head *bh = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 	struct mmp_struct *mmp = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 	u32 seq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 	unsigned int mmp_check_interval = le16_to_cpu(es->s_mmp_update_interval);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 	unsigned int wait_time = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 	int retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 	if (mmp_block < le32_to_cpu(es->s_first_data_block) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 	    mmp_block >= ext4_blocks_count(es)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 		ext4_warning(sb, "Invalid MMP block in superblock");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 		goto failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 	retval = read_mmp_block(sb, &bh, mmp_block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 	if (retval)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 		goto failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) 	mmp = (struct mmp_struct *)(bh->b_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) 	if (mmp_check_interval < EXT4_MMP_MIN_CHECK_INTERVAL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) 		mmp_check_interval = EXT4_MMP_MIN_CHECK_INTERVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 	 * If check_interval in MMP block is larger, use that instead of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 	 * update_interval from the superblock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) 	if (le16_to_cpu(mmp->mmp_check_interval) > mmp_check_interval)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 		mmp_check_interval = le16_to_cpu(mmp->mmp_check_interval);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) 	seq = le32_to_cpu(mmp->mmp_seq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 	if (seq == EXT4_MMP_SEQ_CLEAN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) 		goto skip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) 	if (seq == EXT4_MMP_SEQ_FSCK) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) 		dump_mmp_msg(sb, mmp, "fsck is running on the filesystem");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) 		goto failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) 	wait_time = min(mmp_check_interval * 2 + 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) 			mmp_check_interval + 60);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) 	/* Print MMP interval if more than 20 secs. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) 	if (wait_time > EXT4_MMP_MIN_CHECK_INTERVAL * 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) 		ext4_warning(sb, "MMP interval %u higher than expected, please"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) 			     " wait.\n", wait_time * 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) 	if (schedule_timeout_interruptible(HZ * wait_time) != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) 		ext4_warning(sb, "MMP startup interrupted, failing mount\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) 		goto failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) 	retval = read_mmp_block(sb, &bh, mmp_block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) 	if (retval)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) 		goto failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) 	mmp = (struct mmp_struct *)(bh->b_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) 	if (seq != le32_to_cpu(mmp->mmp_seq)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) 		dump_mmp_msg(sb, mmp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) 			     "Device is already active on another node.");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) 		goto failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) skip:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) 	 * write a new random sequence number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) 	seq = mmp_new_seq();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) 	mmp->mmp_seq = cpu_to_le32(seq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) 	retval = write_mmp_block(sb, bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) 	if (retval)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) 		goto failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) 	 * wait for MMP interval and check mmp_seq.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) 	if (schedule_timeout_interruptible(HZ * wait_time) != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) 		ext4_warning(sb, "MMP startup interrupted, failing mount");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) 		goto failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) 	retval = read_mmp_block(sb, &bh, mmp_block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) 	if (retval)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) 		goto failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) 	mmp = (struct mmp_struct *)(bh->b_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) 	if (seq != le32_to_cpu(mmp->mmp_seq)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) 		dump_mmp_msg(sb, mmp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) 			     "Device is already active on another node.");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) 		goto failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) 	EXT4_SB(sb)->s_mmp_bh = bh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) 	 * Start a kernel thread to update the MMP block periodically.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) 	EXT4_SB(sb)->s_mmp_tsk = kthread_run(kmmpd, sb, "kmmpd-%.*s",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) 					     (int)sizeof(mmp->mmp_bdevname),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) 					     bdevname(bh->b_bdev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) 						      mmp->mmp_bdevname));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) 	if (IS_ERR(EXT4_SB(sb)->s_mmp_tsk)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) 		EXT4_SB(sb)->s_mmp_tsk = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) 		ext4_warning(sb, "Unable to create kmmpd thread for %s.",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) 			     sb->s_id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) 		goto failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) failed:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) 	brelse(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) 	return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) }