teach logfc() to handle prefices, give it saner calling conventions (9f09f649) · Commits · 戴 / test

fs/fs_context.c

+17 −46

Original line number	Diff line number	Diff line
		@@ -388,64 +388,33 @@ EXPORT_SYMBOL(vfs_dup_fs_context);
		* @fc: The filesystem context to log to.
		* @fmt: The format of the buffer.
		*/
		void logfc(struct fs_context fc, const char fmt, ...)
		void logfc(struct fc_log log, const char prefix, char level, const char *fmt, ...)
		{
		static const char store_failure[] = "OOM: Can't store error string";
		struct fc_log *log = fc ? fc->log : NULL;
		const char *p;
		va_list va;
		char *q;
		u8 freeable;
		struct va_format vaf = {.fmt = fmt, .va = &va};

		va_start(va, fmt);
		if (!strchr(fmt, '%')) {
		p = fmt;
		goto unformatted_string;
		}
		if (strcmp(fmt, "%s") == 0) {
		p = va_arg(va, const char *);
		goto unformatted_string;
		}

		q = kvasprintf(GFP_KERNEL, fmt, va);
		copied_string:
		if (!q)
		goto store_failure;
		freeable = 1;
		goto store_string;

		unformatted_string:
		if ((unsigned long)p >= (unsigned long)__start_rodata &&
		(unsigned long)p < (unsigned long)__end_rodata)
		goto const_string;
		if (log && within_module_core((unsigned long)p, log->owner))
		goto const_string;
		q = kstrdup(p, GFP_KERNEL);
		goto copied_string;

		store_failure:
		p = store_failure;
		const_string:
		q = (char *)p;
		freeable = 0;
		store_string:
		if (!log) {
		switch (fmt[0]) {
		switch (level) {
		case 'w':
		printk(KERN_WARNING "%s\n", q + 2);
		printk(KERN_WARNING "%s%s%pV\n", prefix ? prefix : "",
		prefix ? ": " : "", &vaf);
		break;
		case 'e':
		printk(KERN_ERR "%s\n", q + 2);
		printk(KERN_ERR "%s%s%pV\n", prefix ? prefix : "",
		prefix ? ": " : "", &vaf);
		break;
		default:
		printk(KERN_NOTICE "%s\n", q + 2);
		printk(KERN_NOTICE "%s%s%pV\n", prefix ? prefix : "",
		prefix ? ": " : "", &vaf);
		break;
		}
		if (freeable)
		kfree(q);
		} else {
		unsigned int logsize = ARRAY_SIZE(log->buffer);
		u8 index;
		char *q = kasprintf(GFP_KERNEL, "%c %s%s%pV\n", level,
		prefix ? prefix : "",
		prefix ? ": " : "", &vaf);

		index = log->head & (logsize - 1);
		BUILD_BUG_ON(sizeof(log->head) != sizeof(u8) \|\|
		@@ -457,9 +426,11 @@ store_string:
		log->tail++;
		}

		log->buffer[index] = q;
		log->buffer[index] = q ? q : "OOM: Can't store error string";
		if (q)
		log->need_free \|= 1 << index;
		else
		log->need_free &= ~(1 << index);
		log->need_free \|= freeable << index;
		log->head++;
		}
		va_end(va);

include/linux/fs_context.h

+10 −6

Original line number	Diff line number	Diff line
		@@ -181,9 +181,13 @@ struct fc_log {
		char *buffer[8];
		};

		extern __attribute__((format(printf, 2, 3)))
		void logfc(struct fs_context fc, const char fmt, ...);
		extern __attribute__((format(printf, 4, 5)))
		void logfc(struct fc_log log, const char prefix, char level, const char *fmt, ...);

		#define __logfc(fc, l, fmt, ...) ({ \
		struct fs_context *__fc = (fc); \
		logfc(__fc ? __fc->log : NULL, NULL, \
		l, fmt, ## __VA_ARGS__);})
		/**
		* infof - Store supplementary informational message
		* @fc: The context in which to log the informational message
		@@ -192,7 +196,7 @@ void logfc(struct fs_context fc, const char fmt, ...);
		* Store the supplementary informational message for the process if the process
		* has enabled the facility.
		*/
		#define infof(fc, fmt, ...) ({ logfc(fc, "i "fmt, ## __VA_ARGS__); })
		#define infof(fc, fmt, ...) __logfc(fc, 'i', fmt, ## __VA_ARGS__)

		/**
		* warnf - Store supplementary warning message
		@@ -202,7 +206,7 @@ void logfc(struct fs_context fc, const char fmt, ...);
		* Store the supplementary warning message for the process if the process has
		* enabled the facility.
		*/
		#define warnf(fc, fmt, ...) ({ logfc(fc, "w "fmt, ## __VA_ARGS__); })
		#define warnf(fc, fmt, ...) __logfc(fc, 'w', fmt, ## __VA_ARGS__)

		/**
		* errorf - Store supplementary error message
		@@ -212,7 +216,7 @@ void logfc(struct fs_context fc, const char fmt, ...);
		* Store the supplementary error message for the process if the process has
		* enabled the facility.
		*/
		#define errorf(fc, fmt, ...) ({ logfc(fc, "e "fmt, ## __VA_ARGS__); })
		#define errorf(fc, fmt, ...) __logfc(fc, 'e', fmt, ## __VA_ARGS__)

		/**
		* invalf - Store supplementary invalid argument error message
		@@ -222,6 +226,6 @@ void logfc(struct fs_context fc, const char fmt, ...);
		* Store the supplementary error message for the process if the process has
		* enabled the facility and return -EINVAL.
		*/
		#define invalf(fc, fmt, ...) ({ errorf(fc, fmt, ## __VA_ARGS__); -EINVAL; })
		#define invalf(fc, fmt, ...) (errorf(fc, fmt, ## __VA_ARGS__), -EINVAL)

		#endif /* _LINUX_FS_CONTEXT_H */

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