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ded85c19 HR |
1 | /* |
2 | * scsi_logging.c | |
3 | * | |
4 | * Copyright (C) 2014 SUSE Linux Products GmbH | |
5 | * Copyright (C) 2014 Hannes Reinecke <hare@suse.de> | |
6 | * | |
7 | * This file is released under the GPLv2 | |
8 | */ | |
9 | ||
10 | #include <linux/kernel.h> | |
11 | #include <linux/atomic.h> | |
12 | ||
13 | #include <scsi/scsi.h> | |
14 | #include <scsi/scsi_cmnd.h> | |
15 | #include <scsi/scsi_device.h> | |
16 | #include <scsi/scsi_dbg.h> | |
17 | ||
18 | #define SCSI_LOG_SPOOLSIZE 4096 | |
19 | #define SCSI_LOG_BUFSIZE 128 | |
20 | ||
21 | #if (SCSI_LOG_SPOOLSIZE / SCSI_LOG_BUFSIZE) > BITS_PER_LONG | |
22 | #warning SCSI logging bitmask too large | |
23 | #endif | |
24 | ||
25 | struct scsi_log_buf { | |
26 | char buffer[SCSI_LOG_SPOOLSIZE]; | |
27 | unsigned long map; | |
28 | }; | |
29 | ||
30 | static DEFINE_PER_CPU(struct scsi_log_buf, scsi_format_log); | |
31 | ||
32 | static char *scsi_log_reserve_buffer(size_t *len) | |
33 | { | |
34 | struct scsi_log_buf *buf; | |
35 | unsigned long map_bits = sizeof(buf->buffer) / SCSI_LOG_BUFSIZE; | |
36 | unsigned long idx = 0; | |
37 | ||
38 | preempt_disable(); | |
39 | buf = this_cpu_ptr(&scsi_format_log); | |
40 | idx = find_first_zero_bit(&buf->map, map_bits); | |
41 | if (likely(idx < map_bits)) { | |
42 | while (test_and_set_bit(idx, &buf->map)) { | |
43 | idx = find_next_zero_bit(&buf->map, map_bits, idx); | |
44 | if (idx >= map_bits) | |
45 | break; | |
46 | } | |
47 | } | |
48 | if (WARN_ON(idx >= map_bits)) { | |
49 | preempt_enable(); | |
50 | return NULL; | |
51 | } | |
52 | *len = SCSI_LOG_BUFSIZE; | |
53 | return buf->buffer + idx * SCSI_LOG_BUFSIZE; | |
54 | } | |
55 | ||
56 | static void scsi_log_release_buffer(char *bufptr) | |
57 | { | |
58 | struct scsi_log_buf *buf; | |
59 | unsigned long idx; | |
60 | int ret; | |
61 | ||
62 | buf = this_cpu_ptr(&scsi_format_log); | |
63 | if (bufptr >= buf->buffer && | |
64 | bufptr < buf->buffer + SCSI_LOG_SPOOLSIZE) { | |
65 | idx = (bufptr - buf->buffer) / SCSI_LOG_BUFSIZE; | |
66 | ret = test_and_clear_bit(idx, &buf->map); | |
67 | WARN_ON(!ret); | |
68 | } | |
69 | preempt_enable(); | |
70 | } | |
71 | ||
72 | int sdev_prefix_printk(const char *level, const struct scsi_device *sdev, | |
73 | const char *name, const char *fmt, ...) | |
74 | { | |
75 | va_list args; | |
76 | char *logbuf; | |
77 | size_t off = 0, logbuf_len; | |
78 | int ret; | |
79 | ||
80 | if (!sdev) | |
81 | return 0; | |
82 | ||
83 | logbuf = scsi_log_reserve_buffer(&logbuf_len); | |
84 | if (!logbuf) | |
85 | return 0; | |
86 | ||
87 | if (name) | |
88 | off += scnprintf(logbuf + off, logbuf_len - off, | |
89 | "[%s] ", name); | |
90 | va_start(args, fmt); | |
91 | off += vscnprintf(logbuf + off, logbuf_len - off, fmt, args); | |
92 | va_end(args); | |
93 | ret = dev_printk(level, &sdev->sdev_gendev, "%s", logbuf); | |
94 | scsi_log_release_buffer(logbuf); | |
95 | return ret; | |
96 | } | |
97 | EXPORT_SYMBOL(sdev_prefix_printk); | |
98 | ||
99 | int scmd_printk(const char *level, const struct scsi_cmnd *scmd, | |
100 | const char *fmt, ...) | |
101 | { | |
102 | struct gendisk *disk = scmd->request->rq_disk; | |
103 | va_list args; | |
104 | char *logbuf; | |
105 | size_t off = 0, logbuf_len; | |
106 | int ret; | |
107 | ||
108 | if (!scmd || !scmd->cmnd) | |
109 | return 0; | |
110 | ||
111 | logbuf = scsi_log_reserve_buffer(&logbuf_len); | |
112 | if (!logbuf) | |
113 | return 0; | |
114 | if (disk) | |
115 | off += scnprintf(logbuf + off, logbuf_len - off, | |
116 | "[%s] ", disk->disk_name); | |
aa66ab35 HR |
117 | |
118 | if (scmd->request->tag >= 0) | |
119 | off += scnprintf(logbuf + off, logbuf_len - off, | |
120 | "tag#%d ", scmd->request->tag); | |
ded85c19 HR |
121 | va_start(args, fmt); |
122 | off += vscnprintf(logbuf + off, logbuf_len - off, fmt, args); | |
123 | va_end(args); | |
124 | ret = dev_printk(level, &scmd->device->sdev_gendev, "%s", logbuf); | |
125 | scsi_log_release_buffer(logbuf); | |
126 | return ret; | |
127 | } | |
128 | EXPORT_SYMBOL(scmd_printk); |