block: Supress Buffer I/O errors when SCSI REQ_QUIET flag set

Allow the scsi request REQ_QUIET flag to be propagated to the buffer file system layer. The basic ideas is to pass the flag from the scsi request to the bio (block IO) and then to the buffer layer. The buffer layer can then suppress needless printks. This patch declutters the kernel log by removed the 40-50 (per lun) buffer io error messages seen during a boot in my multipath setup . It is a good chance any real errors will be missed in the "noise" it the logs without this patch. During boot I see blocks of messages like " __ratelimit: 211 callbacks suppressed Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242847 Buffer I/O error on device sdm, logical block 1 Buffer I/O error on device sdm, logical block 5242878 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242872 " in my logs. My disk environment is multipath fiber channel using the SCSI_DH_RDAC code and multipathd. This topology includes an "active" and "ghost" path for each lun. IO's to the "ghost" path will never complete and the SCSI layer, via the scsi device handler rdac code, quick returns the IOs to theses paths and sets the REQ_QUIET scsi flag to suppress the scsi layer messages. I am wanting to extend the QUIET behavior to include the buffer file system layer to deal with these errors as well. I have been running this patch for a while now on several boxes without issue. A few runs of bonnie++ show no noticeable difference in performance in my setup. Thanks for John Stultz for the quiet_error finalization. Submitted-by: Keith Mannthey <kmannth@us.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

block: Supress Buffer I/O errors when SCSI REQ_QUIET flag set
Allow the scsi request REQ_QUIET flag to be propagated to the buffer file system layer. The basic ideas is to pass the flag from the scsi request to the bio (block IO) and then to the buffer layer. The buffer layer can then suppress needless printks. This patch declutters the kernel log by removed the 40-50 (per lun) buffer io error messages seen during a boot in my multipath setup . It is a good chance any real errors will be missed in the "noise" it the logs without this patch. During boot I see blocks of messages like " __ratelimit: 211 callbacks suppressed Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242847 Buffer I/O error on device sdm, logical block 1 Buffer I/O error on device sdm, logical block 5242878 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242872 " in my logs. My disk environment is multipath fiber channel using the SCSI_DH_RDAC code and multipathd. This topology includes an "active" and "ghost" path for each lun. IO's to the "ghost" path will never complete and the SCSI layer, via the scsi device handler rdac code, quick returns the IOs to theses paths and sets the REQ_QUIET scsi flag to suppress the scsi layer messages. I am wanting to extend the QUIET behavior to include the buffer file system layer to deal with these errors as well. I have been running this patch for a while now on several boxes without issue. A few runs of bonnie++ show no noticeable difference in performance in my setup. Thanks for John Stultz for the quiet_error finalization. Submitted-by: Keith Mannthey <kmannth@us.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Keith Mannthey · Jens Axboe
1 parent 7c239517d9
Showing 4 changed files with 20 additions and 4 deletions Side-by-side Diff
block/blk-core.c
fs/buffer.c
include/linux/bio.h
include/linux/buffer_head.h
@@ -153,6 +153,9 @@
 			nbytes = bio->bi_size;
 		}
  
+		if (unlikely(rq->cmd_flags & REQ_QUIET))
+			set_bit(BIO_QUIET, &bio->bi_flags);
+
 		bio->bi_size -= nbytes;
 		bio->bi_sector += (nbytes >> 9);
  
@@ -99,10 +99,18 @@
 	page_cache_release(page);
 }
  
+
+static int quiet_error(struct buffer_head *bh)
+{
+	if (!test_bit(BH_Quiet, &bh->b_state) && printk_ratelimit())
+		return 0;
+	return 1;
+}
+
+
 static void buffer_io_error(struct buffer_head *bh)
 {
 	char b[BDEVNAME_SIZE];
-
 	printk(KERN_ERR "Buffer I/O error on device %s, logical block %Lu\n",
 			bdevname(bh->b_bdev, b),
 			(unsigned long long)bh->b_blocknr);
@@ -144,7 +152,7 @@
 	if (uptodate) {
 		set_buffer_uptodate(bh);
 	} else {
-		if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
+		if (!buffer_eopnotsupp(bh) && !quiet_error(bh)) {
 			buffer_io_error(bh);
 			printk(KERN_WARNING "lost page write due to "
 					"I/O error on %s\n",
@@ -394,7 +402,7 @@
 		set_buffer_uptodate(bh);
 	} else {
 		clear_buffer_uptodate(bh);
-		if (printk_ratelimit())
+		if (!quiet_error(bh))
 			buffer_io_error(bh);
 		SetPageError(page);
 	}
@@ -455,7 +463,7 @@
 	if (uptodate) {
 		set_buffer_uptodate(bh);
 	} else {
-		if (printk_ratelimit()) {
+		if (!quiet_error(bh)) {
 			buffer_io_error(bh);
 			printk(KERN_WARNING "lost page write due to "
 					"I/O error on %s\n",
@@ -2912,6 +2920,9 @@
 		set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
 		set_bit(BH_Eopnotsupp, &bh->b_state);
 	}
+
+	if (unlikely (test_bit(BIO_QUIET,&bio->bi_flags)))
+		set_bit(BH_Quiet, &bh->b_state);
  
 	bh->b_end_io(bh, test_bit(BIO_UPTODATE, &bio->bi_flags));
 	bio_put(bio);
@@ -117,6 +117,7 @@
 #define BIO_CPU_AFFINE	8	/* complete bio on same CPU as submitted */
 #define BIO_NULL_MAPPED 9	/* contains invalid user pages */
 #define BIO_FS_INTEGRITY 10	/* fs owns integrity data, not block layer */
+#define BIO_QUIET	11	/* Make BIO Quiet */
 #define bio_flagged(bio, flag)	((bio)->bi_flags & (1 << (flag)))
  
 /*
@@ -35,6 +35,7 @@
 	BH_Ordered,	/* ordered write */
 	BH_Eopnotsupp,	/* operation not supported (barrier) */
 	BH_Unwritten,	/* Buffer is allocated on disk but not written */
+	BH_Quiet,	/* Buffer Error Prinks to be quiet */
  
 	BH_PrivateStart,/* not a state bit, but the first bit available
 			 * for private allocation by other entities
...	...	@@ -153,6 +153,9 @@
153	153	nbytes = bio->bi_size;
154	154	}
155	155
	156	+ if (unlikely(rq->cmd_flags & REQ_QUIET))
	157	+ set_bit(BIO_QUIET, &bio->bi_flags);
	158	+
156	159	bio->bi_size -= nbytes;
157	160	bio->bi_sector += (nbytes >> 9);
158	161
...	...	@@ -99,10 +99,18 @@
99	99	page_cache_release(page);
100	100	}
101	101
	102	+
	103	+static int quiet_error(struct buffer_head *bh)
	104	+{
	105	+ if (!test_bit(BH_Quiet, &bh->b_state) && printk_ratelimit())
	106	+ return 0;
	107	+ return 1;
	108	+}
	109	+
	110	+
102	111	static void buffer_io_error(struct buffer_head *bh)
103	112	{
104	113	char b[BDEVNAME_SIZE];
105		-
106	114	printk(KERN_ERR "Buffer I/O error on device %s, logical block %Lu\n",
107	115	bdevname(bh->b_bdev, b),
108	116	(unsigned long long)bh->b_blocknr);
...	...	@@ -144,7 +152,7 @@
144	152	if (uptodate) {
145	153	set_buffer_uptodate(bh);
146	154	} else {
147		- if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
	155	+ if (!buffer_eopnotsupp(bh) && !quiet_error(bh)) {
148	156	buffer_io_error(bh);
149	157	printk(KERN_WARNING "lost page write due to "
150	158	"I/O error on %s\n",
...	...	@@ -394,7 +402,7 @@
394	402	set_buffer_uptodate(bh);
395	403	} else {
396	404	clear_buffer_uptodate(bh);
397		- if (printk_ratelimit())
	405	+ if (!quiet_error(bh))
398	406	buffer_io_error(bh);
399	407	SetPageError(page);
400	408	}
...	...	@@ -455,7 +463,7 @@
455	463	if (uptodate) {
456	464	set_buffer_uptodate(bh);
457	465	} else {
458		- if (printk_ratelimit()) {
	466	+ if (!quiet_error(bh)) {
459	467	buffer_io_error(bh);
460	468	printk(KERN_WARNING "lost page write due to "
461	469	"I/O error on %s\n",
...	...	@@ -2912,6 +2920,9 @@
2912	2920	set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
2913	2921	set_bit(BH_Eopnotsupp, &bh->b_state);
2914	2922	}
	2923	+
	2924	+ if (unlikely (test_bit(BIO_QUIET,&bio->bi_flags)))
	2925	+ set_bit(BH_Quiet, &bh->b_state);
2915	2926
2916	2927	bh->b_end_io(bh, test_bit(BIO_UPTODATE, &bio->bi_flags));
2917	2928	bio_put(bio);
...	...	@@ -117,6 +117,7 @@
117	117	#define BIO_CPU_AFFINE 8 /* complete bio on same CPU as submitted */
118	118	#define BIO_NULL_MAPPED 9 /* contains invalid user pages */
119	119	#define BIO_FS_INTEGRITY 10 /* fs owns integrity data, not block layer */
	120	+#define BIO_QUIET 11 /* Make BIO Quiet */
120	121	#define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag)))
121	122
122	123	/*
...	...	@@ -35,6 +35,7 @@
35	35	BH_Ordered, /* ordered write */
36	36	BH_Eopnotsupp, /* operation not supported (barrier) */
37	37	BH_Unwritten, /* Buffer is allocated on disk but not written */
	38	+ BH_Quiet, /* Buffer Error Prinks to be quiet */
38	39
39	40	BH_PrivateStart,/* not a state bit, but the first bit available
40	41	* for private allocation by other entities