Revision 7bf811a595a895b7a886dcf218d0d34f97df76dc authored by Josef Bacik on 08 October 2013, 02:11:09 UTC, committed by Chris Mason on 11 October 2013, 01:27:56 UTC
Liu fixed part of this problem and unfortunately I steered him in slightly the
wrong direction and so didn't completely fix the problem.  The problem is we
limit the size of the delalloc range we are looking for to max bytes and then we
try to lock that range.  If we fail to lock the pages in that range we will
shrink the max bytes to a single page and re loop.  However if our first page is
inside of the delalloc range then we will end up limiting the end of the range
to a period before our first page.  This is illustrated below

[0 -------- delalloc range --------- 256mb]
                                  [page]

So find_delalloc_range will return with delalloc_start as 0 and end as 128mb,
and then we will notice that delalloc_start < *start and adjust it up, but not
adjust delalloc_end up, so things go sideways.  To fix this we need to not limit
the max bytes in find_delalloc_range, but in find_lock_delalloc_range and that
way we don't end up with this confusion.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
1 parent 4871c15
Raw File
kmod.h
#ifndef __LINUX_KMOD_H__
#define __LINUX_KMOD_H__

/*
 *	include/linux/kmod.h
 *
 *      This program is free software; you can redistribute it and/or modify
 *      it under the terms of the GNU General Public License as published by
 *      the Free Software Foundation; either version 2 of the License, or
 *      (at your option) any later version.
 *
 *      This program is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *      GNU General Public License for more details.
 *
 *      You should have received a copy of the GNU General Public License
 *      along with this program; if not, write to the Free Software
 *      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/gfp.h>
#include <linux/stddef.h>
#include <linux/errno.h>
#include <linux/compiler.h>
#include <linux/workqueue.h>
#include <linux/sysctl.h>

#define KMOD_PATH_LEN 256

#ifdef CONFIG_MODULES
extern char modprobe_path[]; /* for sysctl */
/* modprobe exit status on success, -ve on error.  Return value
 * usually useless though. */
extern __printf(2, 3)
int __request_module(bool wait, const char *name, ...);
#define request_module(mod...) __request_module(true, mod)
#define request_module_nowait(mod...) __request_module(false, mod)
#define try_then_request_module(x, mod...) \
	((x) ?: (__request_module(true, mod), (x)))
#else
static inline int request_module(const char *name, ...) { return -ENOSYS; }
static inline int request_module_nowait(const char *name, ...) { return -ENOSYS; }
#define try_then_request_module(x, mod...) (x)
#endif


struct cred;
struct file;

#define UMH_NO_WAIT	0	/* don't wait at all */
#define UMH_WAIT_EXEC	1	/* wait for the exec, but not the process */
#define UMH_WAIT_PROC	2	/* wait for the process to complete */
#define UMH_KILLABLE	4	/* wait for EXEC/PROC killable */

struct subprocess_info {
	struct work_struct work;
	struct completion *complete;
	char *path;
	char **argv;
	char **envp;
	int wait;
	int retval;
	int (*init)(struct subprocess_info *info, struct cred *new);
	void (*cleanup)(struct subprocess_info *info);
	void *data;
};

extern int
call_usermodehelper(char *path, char **argv, char **envp, int wait);

extern struct subprocess_info *
call_usermodehelper_setup(char *path, char **argv, char **envp, gfp_t gfp_mask,
			  int (*init)(struct subprocess_info *info, struct cred *new),
			  void (*cleanup)(struct subprocess_info *), void *data);

extern int
call_usermodehelper_exec(struct subprocess_info *info, int wait);

extern struct ctl_table usermodehelper_table[];

enum umh_disable_depth {
	UMH_ENABLED = 0,
	UMH_FREEZING,
	UMH_DISABLED,
};

extern void usermodehelper_init(void);

extern int __usermodehelper_disable(enum umh_disable_depth depth);
extern void __usermodehelper_set_disable_depth(enum umh_disable_depth depth);

static inline int usermodehelper_disable(void)
{
	return __usermodehelper_disable(UMH_DISABLED);
}

static inline void usermodehelper_enable(void)
{
	__usermodehelper_set_disable_depth(UMH_ENABLED);
}

extern int usermodehelper_read_trylock(void);
extern long usermodehelper_read_lock_wait(long timeout);
extern void usermodehelper_read_unlock(void);

#endif /* __LINUX_KMOD_H__ */
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