scnprintf returns the number of bytes written to the buffer.
snprintf returns the size of the buffer needed to satisfy
the request.
Prefer scnprintf when result is being used as the number
of bytes in a buffer.
Use snprintf when the result is used for sizing or resizing
a buffer.
Signed-off-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Change-Id: I8c4b8f7dcc081f8b9dfffc35059011172be2e091
Reviewed-on: https://review.whamcloud.com/36901
Reviewed-by: Petros Koutoupis <petros.koutoupis@hpe.com>
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Ben Evans <beevans@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
}
int libcfs_debug_msg(struct libcfs_debug_msg_data *msgdata,
}
int libcfs_debug_msg(struct libcfs_debug_msg_data *msgdata,
- const char *format, ...)
+ const char *format, ...)
- struct cfs_trace_cpu_data *tcd = NULL;
- struct ptldebug_header header = {0};
- struct cfs_trace_page *tage;
- /* string_buf is used only if tcd != NULL, and is always set then */
- char *string_buf = NULL;
- char *debug_buf;
- int known_size;
- int needed = 85; /* average message length */
- int max_nob;
- va_list ap;
- int i;
- int remain;
- int mask = msgdata->msg_mask;
- char *file = (char *)msgdata->msg_file;
+ struct cfs_trace_cpu_data *tcd = NULL;
+ struct ptldebug_header header = {0};
+ struct cfs_trace_page *tage;
+ /* string_buf is used only if tcd != NULL, and is always set then */
+ char *string_buf = NULL;
+ char *debug_buf;
+ int known_size;
+ int needed = 85; /* seeded with average message length */
+ int max_nob;
+ va_list ap;
+ int retry;
+ int mask = msgdata->msg_mask;
+ char *file = (char *)msgdata->msg_file;
struct cfs_debug_limit_state *cdls = msgdata->msg_cdls;
struct cfs_debug_limit_state *cdls = msgdata->msg_cdls;
- if (strchr(file, '/'))
- file = strrchr(file, '/') + 1;
+ if (strchr(file, '/'))
+ file = strrchr(file, '/') + 1;
- tcd = cfs_trace_get_tcd();
+ tcd = cfs_trace_get_tcd();
- /* cfs_trace_get_tcd() grabs a lock, which disables preemption and
- * pins us to a particular CPU. This avoids an smp_processor_id()
- * warning on Linux when debugging is enabled. */
- cfs_set_ptldebug_header(&header, msgdata, CDEBUG_STACK());
+ /* cfs_trace_get_tcd() grabs a lock, which disables preemption and
+ * pins us to a particular CPU. This avoids an smp_processor_id()
+ * warning on Linux when debugging is enabled.
+ */
+ cfs_set_ptldebug_header(&header, msgdata, CDEBUG_STACK());
- if (tcd == NULL) /* arch may not log in IRQ context */
- goto console;
+ if (!tcd) /* arch may not log in IRQ context */
+ goto console;
- if (tcd->tcd_cur_pages == 0)
- header.ph_flags |= PH_FLAG_FIRST_RECORD;
+ if (tcd->tcd_cur_pages == 0)
+ header.ph_flags |= PH_FLAG_FIRST_RECORD;
- if (tcd->tcd_shutting_down) {
- cfs_trace_put_tcd(tcd);
- tcd = NULL;
- goto console;
- }
+ if (tcd->tcd_shutting_down) {
+ cfs_trace_put_tcd(tcd);
+ tcd = NULL;
+ goto console;
+ }
known_size = strlen(file) + 1;
known_size = strlen(file) + 1;
- if (msgdata->msg_fn)
- known_size += strlen(msgdata->msg_fn) + 1;
+ if (msgdata->msg_fn)
+ known_size += strlen(msgdata->msg_fn) + 1;
- if (libcfs_debug_binary)
- known_size += sizeof(header);
+ if (libcfs_debug_binary)
+ known_size += sizeof(header);
- /*/
- * '2' used because vsnprintf return real size required for output
- * _without_ terminating NULL.
- * if needed is to small for this format.
- */
- for (i = 0; i < 2; i++) {
- tage = cfs_trace_get_tage(tcd, needed + known_size + 1);
- if (tage == NULL) {
+ /*
+ * May perform an additional pass to update 'needed' and increase
+ * tage buffer size to match vsnprintf reported size required
+ * On the second pass (retry=1) use vscnprintf [which returns
+ * number of bytes written not including the terminating nul]
+ * to clarify `needed` is used as number of bytes written
+ * for the remainder of this function
+ */
+ for (retry = 0; retry < 2; retry++) {
+ tage = cfs_trace_get_tage(tcd, needed + known_size + 1);
+ if (!tage) {
if (needed + known_size > PAGE_SIZE)
if (needed + known_size > PAGE_SIZE)
- cfs_trace_put_tcd(tcd);
- tcd = NULL;
- goto console;
- }
+ cfs_trace_put_tcd(tcd);
+ tcd = NULL;
+ goto console;
+ }
string_buf = (char *)page_address(tage->page) +
tage->used + known_size;
string_buf = (char *)page_address(tage->page) +
tage->used + known_size;
- needed = 0;
- remain = max_nob - needed;
- if (remain < 0)
- remain = 0;
-
- needed += vsnprintf(string_buf + needed, remain,
- format, ap);
+ if (retry)
+ needed = vscnprintf(string_buf, max_nob, format, ap);
+ else
+ needed = vsnprintf(string_buf, max_nob, format, ap);
- if (needed < max_nob) /* well. printing ok.. */
- break;
- }
+ if (needed < max_nob) /* well. printing ok.. */
+ break;
+ }
+ /* `needed` is actual bytes written to string_buf */
if (*(string_buf + needed - 1) != '\n') {
pr_info("Lustre: format at %s:%d:%s doesn't end in newline\n",
file, msgdata->msg_line, msgdata->msg_fn);
if (*(string_buf + needed - 1) != '\n') {
pr_info("Lustre: format at %s:%d:%s doesn't end in newline\n",
file, msgdata->msg_line, msgdata->msg_fn);
file, msgdata->msg_line, msgdata->msg_fn);
}
file, msgdata->msg_line, msgdata->msg_fn);
}
- header.ph_len = known_size + needed;
+ header.ph_len = known_size + needed;
debug_buf = (char *)page_address(tage->page) + tage->used;
debug_buf = (char *)page_address(tage->page) + tage->used;
- if (libcfs_debug_binary) {
- memcpy(debug_buf, &header, sizeof(header));
- tage->used += sizeof(header);
- debug_buf += sizeof(header);
- }
+ if (libcfs_debug_binary) {
+ memcpy(debug_buf, &header, sizeof(header));
+ tage->used += sizeof(header);
+ debug_buf += sizeof(header);
+ }
- strcpy(debug_buf, file);
- tage->used += strlen(file) + 1;
- debug_buf += strlen(file) + 1;
+ strlcpy(debug_buf, file, PAGE_SIZE - tage->used);
+ tage->used += strlen(file) + 1;
+ debug_buf += strlen(file) + 1;
- if (msgdata->msg_fn) {
- strcpy(debug_buf, msgdata->msg_fn);
- tage->used += strlen(msgdata->msg_fn) + 1;
- debug_buf += strlen(msgdata->msg_fn) + 1;
- }
+ if (msgdata->msg_fn) {
+ strlcpy(debug_buf, msgdata->msg_fn, PAGE_SIZE - tage->used);
+ tage->used += strlen(msgdata->msg_fn) + 1;
+ debug_buf += strlen(msgdata->msg_fn) + 1;
+ }
- __LASSERT(debug_buf == string_buf);
+ __LASSERT(debug_buf == string_buf);
__LASSERT(tage->used <= PAGE_SIZE);
console:
__LASSERT(tage->used <= PAGE_SIZE);
console:
- if ((mask & libcfs_printk) == 0) {
- /* no console output requested */
- if (tcd != NULL)
- cfs_trace_put_tcd(tcd);
- return 1;
- }
+ if ((mask & libcfs_printk) == 0) {
+ /* no console output requested */
+ if (tcd != NULL)
+ cfs_trace_put_tcd(tcd);
+ return 1;
+ }
if (cdls != NULL) {
if (libcfs_console_ratelimit &&
if (cdls != NULL) {
if (libcfs_console_ratelimit &&
cdls->cdls_next = (jiffies + cdls->cdls_delay) | 1;
}
cdls->cdls_next = (jiffies + cdls->cdls_delay) | 1;
}
- if (tcd != NULL) {
- cfs_print_to_console(&header, mask, string_buf, needed, file,
- msgdata->msg_fn);
- cfs_trace_put_tcd(tcd);
- } else {
- string_buf = cfs_trace_get_console_buffer();
-
- needed = 0;
- remain = CFS_TRACE_CONSOLE_BUFFER_SIZE - needed;
- if (remain > 0) {
- va_start(ap, format);
- needed += vsnprintf(string_buf+needed, remain,
- format, ap);
- va_end(ap);
- }
+ if (tcd) {
+ cfs_print_to_console(&header, mask, string_buf, needed, file,
+ msgdata->msg_fn);
+ cfs_trace_put_tcd(tcd);
+ } else {
+ string_buf = cfs_trace_get_console_buffer();
+
+ va_start(ap, format);
+ needed = vscnprintf(string_buf, CFS_TRACE_CONSOLE_BUFFER_SIZE,
+ format, ap);
+ va_end(ap);
- cfs_print_to_console(&header, mask,
- string_buf, needed, file, msgdata->msg_fn);
+ cfs_print_to_console(&header, mask,
+ string_buf, needed, file, msgdata->msg_fn);
- if (cdls != NULL && cdls->cdls_count != 0) {
- string_buf = cfs_trace_get_console_buffer();
+ if (cdls != NULL && cdls->cdls_count != 0) {
+ string_buf = cfs_trace_get_console_buffer();
- needed = snprintf(string_buf, CFS_TRACE_CONSOLE_BUFFER_SIZE,
- "Skipped %d previous similar message%s\n",
- cdls->cdls_count,
- (cdls->cdls_count > 1) ? "s" : "");
+ needed = scnprintf(string_buf, CFS_TRACE_CONSOLE_BUFFER_SIZE,
+ "Skipped %d previous similar message%s\n",
+ cdls->cdls_count,
+ (cdls->cdls_count > 1) ? "s" : "");
/* Do not allow print this to TTY */
cfs_print_to_console(&header, mask & ~D_TTY, string_buf,
needed, file, msgdata->msg_fn);
put_cpu();
/* Do not allow print this to TTY */
cfs_print_to_console(&header, mask & ~D_TTY, string_buf,
needed, file, msgdata->msg_fn);
put_cpu();
- cdls->cdls_count = 0;
- }
+ cdls->cdls_count = 0;
+ }
}
EXPORT_SYMBOL(libcfs_debug_msg);
}
EXPORT_SYMBOL(libcfs_debug_msg);
git://git.whamcloud.com / fs / lustre-release.git / commitdiff