Revision 31bd61f2bb79e098117d823e054342b03aa87668 authored by Lachlan McIlroy on 17 September 2008, 06:45:37 UTC, committed by Lachlan McIlroy on 17 September 2008, 06:45:37 UTC
Memory allocations for log->l_grant_trace and iclog->ic_trace are done on
demand when the first event is logged. In xlog_state_get_iclog_space() we
call xlog_trace_iclog() under a spinlock and allocating memory here can
cause us to sleep with a spinlock held and deadlock the system.

For the log grant tracing we use KM_NOSLEEP but that means we can lose
trace entries. Since there is no locking to serialize the log grant
tracing we could race and have multiple allocations and leak memory.

So move the allocations to where we initialize the log/iclog structures.
Use KM_NOFS to avoid recursing into the filesystem and drop log->l_trace
since it's not even used.

SGI-PV: 983738

SGI-Modid: xfs-linux-melb:xfs-kern:31896a

Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
1 parent bc45eb8
Raw File
cmdline.c
/*
 * linux/lib/cmdline.c
 * Helper functions generally used for parsing kernel command line
 * and module options.
 *
 * Code and copyrights come from init/main.c and arch/i386/kernel/setup.c.
 *
 * This source code is licensed under the GNU General Public License,
 * Version 2.  See the file COPYING for more details.
 *
 * GNU Indent formatting options for this file: -kr -i8 -npsl -pcs
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>

/*
 *	If a hyphen was found in get_option, this will handle the
 *	range of numbers, M-N.  This will expand the range and insert
 *	the values[M, M+1, ..., N] into the ints array in get_options.
 */

static int get_range(char **str, int *pint)
{
	int x, inc_counter, upper_range;

	(*str)++;
	upper_range = simple_strtol((*str), NULL, 0);
	inc_counter = upper_range - *pint;
	for (x = *pint; x < upper_range; x++)
		*pint++ = x;
	return inc_counter;
}

/**
 *	get_option - Parse integer from an option string
 *	@str: option string
 *	@pint: (output) integer value parsed from @str
 *
 *	Read an int from an option string; if available accept a subsequent
 *	comma as well.
 *
 *	Return values:
 *	0 - no int in string
 *	1 - int found, no subsequent comma
 *	2 - int found including a subsequent comma
 *	3 - hyphen found to denote a range
 */

int get_option (char **str, int *pint)
{
	char *cur = *str;

	if (!cur || !(*cur))
		return 0;
	*pint = simple_strtol (cur, str, 0);
	if (cur == *str)
		return 0;
	if (**str == ',') {
		(*str)++;
		return 2;
	}
	if (**str == '-')
		return 3;

	return 1;
}

/**
 *	get_options - Parse a string into a list of integers
 *	@str: String to be parsed
 *	@nints: size of integer array
 *	@ints: integer array
 *
 *	This function parses a string containing a comma-separated
 *	list of integers, a hyphen-separated range of _positive_ integers,
 *	or a combination of both.  The parse halts when the array is
 *	full, or when no more numbers can be retrieved from the
 *	string.
 *
 *	Return value is the character in the string which caused
 *	the parse to end (typically a null terminator, if @str is
 *	completely parseable).
 */
 
char *get_options(const char *str, int nints, int *ints)
{
	int res, i = 1;

	while (i < nints) {
		res = get_option ((char **)&str, ints + i);
		if (res == 0)
			break;
		if (res == 3) {
			int range_nums;
			range_nums = get_range((char **)&str, ints + i);
			if (range_nums < 0)
				break;
			/*
			 * Decrement the result by one to leave out the
			 * last number in the range.  The next iteration
			 * will handle the upper number in the range
			 */
			i += (range_nums - 1);
		}
		i++;
		if (res == 1)
			break;
	}
	ints[0] = i - 1;
	return (char *)str;
}

/**
 *	memparse - parse a string with mem suffixes into a number
 *	@ptr: Where parse begins
 *	@retptr: (output) Optional pointer to next char after parse completes
 *
 *	Parses a string into a number.  The number stored at @ptr is
 *	potentially suffixed with %K (for kilobytes, or 1024 bytes),
 *	%M (for megabytes, or 1048576 bytes), or %G (for gigabytes, or
 *	1073741824).  If the number is suffixed with K, M, or G, then
 *	the return value is the number multiplied by one kilobyte, one
 *	megabyte, or one gigabyte, respectively.
 */

unsigned long long memparse(char *ptr, char **retptr)
{
	char *endptr;	/* local pointer to end of parsed string */

	unsigned long long ret = simple_strtoull(ptr, &endptr, 0);

	switch (*endptr) {
	case 'G':
	case 'g':
		ret <<= 10;
	case 'M':
	case 'm':
		ret <<= 10;
	case 'K':
	case 'k':
		ret <<= 10;
		endptr++;
	default:
		break;
	}

	if (retptr)
		*retptr = endptr;

	return ret;
}


EXPORT_SYMBOL(memparse);
EXPORT_SYMBOL(get_option);
EXPORT_SYMBOL(get_options);
back to top