export RK_PA3

hc

2024-02-19 151fecfb72a0d602dfe79790602ef64b4e241574

 kernel/fs/ext4/mmp.c
..
..
@@ -39,26 +39,34 @@
39
39
  * Write the MMP block using REQ_SYNC to try to get the block on-disk
40
40
  * faster.
41
41
  */
42
-static int write_mmp_block(struct super_block *sb, struct buffer_head *bh)
42
+static int write_mmp_block_thawed(struct super_block *sb,
43
+				  struct buffer_head *bh)
43
44
 {
44
45
 	struct mmp_struct *mmp = (struct mmp_struct *)(bh->b_data);
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46
 
46
-	/*
47
-	 * We protect against freezing so that we don't create dirty buffers
48
-	 * on frozen filesystem.
49
-	 */
50
-	sb_start_write(sb);
51
47
 	ext4_mmp_csum_set(sb, mmp);
52
48
 	lock_buffer(bh);
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49
 	bh->b_end_io = end_buffer_write_sync;
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50
 	get_bh(bh);
55
51
 	submit_bh(REQ_OP_WRITE, REQ_SYNC | REQ_META | REQ_PRIO, bh);
56
52
 	wait_on_buffer(bh);
57
-	sb_end_write(sb);
58
53
 	if (unlikely(!buffer_uptodate(bh)))
59
54
 		return -EIO;
60
-
61
55
 	return 0;
56
+}
57
+
58
+static int write_mmp_block(struct super_block *sb, struct buffer_head *bh)
59
+{
60
+	int err;
61
+
62
+	/*
63
+	 * We protect against freezing so that we don't create dirty buffers
64
+	 * on frozen filesystem.
65
+	 */
66
+	sb_start_write(sb);
67
+	err = write_mmp_block_thawed(sb, bh);
68
+	sb_end_write(sb);
69
+	return err;
62
70
 }
63
71
 
64
72
 /*
..
..
@@ -290,6 +298,7 @@
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298
 	if (mmp_block < le32_to_cpu(es->s_first_data_block) ||
291
299
 	    mmp_block >= ext4_blocks_count(es)) {
292
300
 		ext4_warning(sb, "Invalid MMP block in superblock");
301
+		retval = -EINVAL;
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302
 		goto failed;
294
303
 	}
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304
 
..
..
@@ -315,6 +324,7 @@
315
324
 
316
325
 	if (seq == EXT4_MMP_SEQ_FSCK) {
317
326
 		dump_mmp_msg(sb, mmp, "fsck is running on the filesystem");
327
+		retval = -EBUSY;
318
328
 		goto failed;
319
329
 	}
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330
 
..
..
@@ -328,6 +338,7 @@
328
338
 
329
339
 	if (schedule_timeout_interruptible(HZ * wait_time) != 0) {
330
340
 		ext4_warning(sb, "MMP startup interrupted, failing mount\n");
341
+		retval = -ETIMEDOUT;
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342
 		goto failed;
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343
 	}
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344
 
..
..
@@ -338,6 +349,7 @@
338
349
 	if (seq != le32_to_cpu(mmp->mmp_seq)) {
339
350
 		dump_mmp_msg(sb, mmp,
340
351
 			     "Device is already active on another node.");
352
+		retval = -EBUSY;
341
353
 		goto failed;
342
354
 	}
343
355
 
..
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@@ -348,7 +360,11 @@
348
360
 	seq = mmp_new_seq();
349
361
 	mmp->mmp_seq = cpu_to_le32(seq);
350
362
 
351
-	retval = write_mmp_block(sb, bh);
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+	/*
364
+	 * On mount / remount we are protected against fs freezing (by s_umount
365
+	 * semaphore) and grabbing freeze protection upsets lockdep
366
+	 */
367
+	retval = write_mmp_block_thawed(sb, bh);
352
368
 	if (retval)
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369
 		goto failed;
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370
 
..
..
@@ -357,6 +373,7 @@
357
373
 	 */
358
374
 	if (schedule_timeout_interruptible(HZ * wait_time) != 0) {
359
375
 		ext4_warning(sb, "MMP startup interrupted, failing mount");
376
+		retval = -ETIMEDOUT;
360
377
 		goto failed;
361
378
 	}
362
379
 
..
..
@@ -367,6 +384,7 @@
367
384
 	if (seq != le32_to_cpu(mmp->mmp_seq)) {
368
385
 		dump_mmp_msg(sb, mmp,
369
386
 			     "Device is already active on another node.");
387
+		retval = -EBUSY;
370
388
 		goto failed;
371
389
 	}
372
390
 
..
..
@@ -383,6 +401,7 @@
383
401
 		EXT4_SB(sb)->s_mmp_tsk = NULL;
384
402
 		ext4_warning(sb, "Unable to create kmmpd thread for %s.",
385
403
 			     sb->s_id);
404
+		retval = -ENOMEM;
386
405
 		goto failed;
387
406
 	}
388
407
 
..
..
@@ -390,5 +409,5 @@
390
409
 
391
410
 failed:
392
411
 	brelse(bh);
393
-	return 1;
412
+	return retval;
394
413
 }