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Commit | Line | Data |
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00e5a55c BS |
1 | Subject: block: Supress Buffer I/O errors when SCSI REQ_QUIET flag set |
2 | From: Keith Mannthey <kmannth@us.ibm.com> | |
3 | Date: Mon Dec 29 08:28:44 2008 +0100: | |
4 | Git: 08bafc0341f2f7920e9045bc32c40299cac8c21b | |
5 | References: bnc#464155 | |
6 | ||
7 | Allow the scsi request REQ_QUIET flag to be propagated to the buffer | |
8 | file system layer. The basic ideas is to pass the flag from the scsi | |
9 | request to the bio (block IO) and then to the buffer layer. The buffer | |
10 | layer can then suppress needless printks. | |
11 | ||
12 | This patch declutters the kernel log by removed the 40-50 (per lun) | |
13 | buffer io error messages seen during a boot in my multipath setup . It | |
14 | is a good chance any real errors will be missed in the "noise" it the | |
15 | logs without this patch. | |
16 | ||
17 | During boot I see blocks of messages like | |
18 | " | |
19 | __ratelimit: 211 callbacks suppressed | |
20 | Buffer I/O error on device sdm, logical block 5242879 | |
21 | Buffer I/O error on device sdm, logical block 5242879 | |
22 | Buffer I/O error on device sdm, logical block 5242847 | |
23 | Buffer I/O error on device sdm, logical block 1 | |
24 | Buffer I/O error on device sdm, logical block 5242878 | |
25 | Buffer I/O error on device sdm, logical block 5242879 | |
26 | Buffer I/O error on device sdm, logical block 5242879 | |
27 | Buffer I/O error on device sdm, logical block 5242879 | |
28 | Buffer I/O error on device sdm, logical block 5242879 | |
29 | Buffer I/O error on device sdm, logical block 5242872 | |
30 | " | |
31 | in my logs. | |
32 | ||
33 | My disk environment is multipath fiber channel using the SCSI_DH_RDAC | |
34 | code and multipathd. This topology includes an "active" and "ghost" | |
35 | path for each lun. IO's to the "ghost" path will never complete and the | |
36 | SCSI layer, via the scsi device handler rdac code, quick returns the IOs | |
37 | to theses paths and sets the REQ_QUIET scsi flag to suppress the scsi | |
38 | layer messages. | |
39 | ||
40 | I am wanting to extend the QUIET behavior to include the buffer file | |
41 | system layer to deal with these errors as well. I have been running this | |
42 | patch for a while now on several boxes without issue. A few runs of | |
43 | bonnie++ show no noticeable difference in performance in my setup. | |
44 | ||
45 | Thanks for John Stultz for the quiet_error finalization. | |
46 | ||
47 | Submitted-by: Keith Mannthey <kmannth@us.ibm.com> | |
48 | Signed-off-by: Jens Axboe <jens.axboe@oracle.com> | |
49 | Signed-off-by: Hannes Reinecke <hare@suse.de> | |
50 | ||
51 | --- | |
52 | block/blk-core.c | 3 +++ | |
53 | fs/buffer.c | 19 +++++++++++++++---- | |
54 | include/linux/bio.h | 1 + | |
55 | include/linux/buffer_head.h | 1 + | |
56 | 4 files changed, 20 insertions(+), 4 deletions(-) | |
57 | ||
58 | --- a/block/blk-core.c | |
59 | +++ b/block/blk-core.c | |
60 | @@ -138,6 +138,9 @@ static void req_bio_endio(struct request | |
61 | nbytes = bio->bi_size; | |
62 | } | |
63 | ||
64 | + if (unlikely(rq->cmd_flags & REQ_QUIET)) | |
65 | + set_bit(BIO_QUIET, &bio->bi_flags); | |
66 | + | |
67 | bio->bi_size -= nbytes; | |
68 | bio->bi_sector += (nbytes >> 9); | |
69 | ||
70 | --- a/fs/buffer.c | |
71 | +++ b/fs/buffer.c | |
72 | @@ -100,10 +100,18 @@ __clear_page_buffers(struct page *page) | |
73 | page_cache_release(page); | |
74 | } | |
75 | ||
76 | + | |
77 | +static int quiet_error(struct buffer_head *bh) | |
78 | +{ | |
79 | + if (!test_bit(BH_Quiet, &bh->b_state) && printk_ratelimit()) | |
80 | + return 0; | |
81 | + return 1; | |
82 | +} | |
83 | + | |
84 | + | |
85 | static void buffer_io_error(struct buffer_head *bh) | |
86 | { | |
87 | char b[BDEVNAME_SIZE]; | |
88 | - | |
89 | printk(KERN_ERR "Buffer I/O error on device %s, logical block %Lu\n", | |
90 | bdevname(bh->b_bdev, b), | |
91 | (unsigned long long)bh->b_blocknr); | |
92 | @@ -145,7 +153,7 @@ void end_buffer_write_sync(struct buffer | |
93 | if (uptodate) { | |
94 | set_buffer_uptodate(bh); | |
95 | } else { | |
96 | - if (!buffer_eopnotsupp(bh) && printk_ratelimit()) { | |
97 | + if (!buffer_eopnotsupp(bh) && !quiet_error(bh)) { | |
98 | buffer_io_error(bh); | |
99 | printk(KERN_WARNING "lost page write due to " | |
100 | "I/O error on %s\n", | |
101 | @@ -395,7 +403,7 @@ static void end_buffer_async_read(struct | |
102 | set_buffer_uptodate(bh); | |
103 | } else { | |
104 | clear_buffer_uptodate(bh); | |
105 | - if (printk_ratelimit()) | |
106 | + if (!quiet_error(bh)) | |
107 | buffer_io_error(bh); | |
108 | SetPageError(page); | |
109 | } | |
110 | @@ -456,7 +464,7 @@ static void end_buffer_async_write(struc | |
111 | if (uptodate) { | |
112 | set_buffer_uptodate(bh); | |
113 | } else { | |
114 | - if (printk_ratelimit()) { | |
115 | + if (!quiet_error(bh)) { | |
116 | buffer_io_error(bh); | |
117 | printk(KERN_WARNING "lost page write due to " | |
118 | "I/O error on %s\n", | |
119 | @@ -2923,6 +2931,9 @@ static void end_bio_bh_io_sync(struct bi | |
120 | set_bit(BH_Eopnotsupp, &bh->b_state); | |
121 | } | |
122 | ||
123 | + if (unlikely (test_bit(BIO_QUIET,&bio->bi_flags))) | |
124 | + set_bit(BH_Quiet, &bh->b_state); | |
125 | + | |
126 | bh->b_end_io(bh, test_bit(BIO_UPTODATE, &bio->bi_flags)); | |
127 | bio_put(bio); | |
128 | } | |
129 | --- a/include/linux/bio.h | |
130 | +++ b/include/linux/bio.h | |
131 | @@ -116,6 +116,7 @@ struct bio { | |
132 | #define BIO_EOPNOTSUPP 7 /* not supported */ | |
133 | #define BIO_CPU_AFFINE 8 /* complete bio on same CPU as submitted */ | |
134 | #define BIO_FS_INTEGRITY 10 /* fs owns integrity data, not block layer */ | |
135 | +#define BIO_QUIET 11 /* Make BIO Quiet */ | |
136 | #define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag))) | |
137 | ||
138 | /* | |
139 | --- a/include/linux/buffer_head.h | |
140 | +++ b/include/linux/buffer_head.h | |
141 | @@ -35,6 +35,7 @@ enum bh_state_bits { | |
142 | BH_Ordered, /* ordered write */ | |
143 | BH_Eopnotsupp, /* operation not supported (barrier) */ | |
144 | BH_Unwritten, /* Buffer is allocated on disk but not written */ | |
145 | + BH_Quiet, /* Buffer Error Prinks to be quiet */ | |
146 | ||
147 | BH_PrivateStart,/* not a state bit, but the first bit available | |
148 | * for private allocation by other entities |