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Commit b7600dba authored by David Woodhouse's avatar David Woodhouse
Browse files

[JFFS2] Fix allocation of summary buffer 



We can't use vmalloc for the buffer we use for writing summaries,
because some drivers may want to DMA from it. So limit the size to 64KiB
and use kmalloc for it instead.

Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent f6ed6f78

fs/jffs2/summary.c

+26 −14
Original line number Diff line number Diff line
@@ -23,6 +23,8 @@ 


int jffs2_sum_init(struct jffs2_sb_info *c)

{

	uint32_t sum_size = max_t(uint32_t, c->sector_size, MAX_SUMMARY_SIZE);



	c->summary = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL);



	if (!c->summary) {
@@ -30,7 +32,7 @@ int jffs2_sum_init(struct jffs2_sb_info *c) 
		return -ENOMEM;

	}



	c->summary->sum_buf = vmalloc(c->sector_size);

	c->summary->sum_buf = kmalloc(sum_size, GFP_KERNEL);



	if (!c->summary->sum_buf) {

		JFFS2_WARNING("Can't allocate buffer for writing out summary information!\n");
@@ -49,7 +51,7 @@ void jffs2_sum_exit(struct jffs2_sb_info *c) 


	jffs2_sum_disable_collecting(c->summary);



	vfree(c->summary->sum_buf);

	kfree(c->summary->sum_buf);

	c->summary->sum_buf = NULL;



	kfree(c->summary);
@@ -676,6 +678,26 @@ static int jffs2_sum_write_data(struct jffs2_sb_info *c, struct jffs2_eraseblock 
	int ret;

	size_t retlen;



	if (padsize + datasize > MAX_SUMMARY_SIZE) {

		/* It won't fit in the buffer. Abort summary for this jeb */

		jffs2_sum_disable_collecting(c->summary);



		JFFS2_WARNING("Summary too big (%d data, %d pad) in eraseblock at %08x\n",

			      datasize, padsize, jeb->offset);

		/* Non-fatal */

		return 0;

	}

	/* Is there enough space for summary? */

	if (padsize < 0) {

		/* don't try to write out summary for this jeb */

		jffs2_sum_disable_collecting(c->summary);



		JFFS2_WARNING("Not enough space for summary, padsize = %d\n",

			      padsize);

		/* Non-fatal */

		return 0;

	}



	memset(c->summary->sum_buf, 0xff, datasize);

	memset(&isum, 0, sizeof(isum));
@@ -821,7 +843,7 @@ int jffs2_sum_write_sumnode(struct jffs2_sb_info *c) 
{

	int datasize, infosize, padsize;

	struct jffs2_eraseblock *jeb;

	int ret;

	int ret = 0;



	dbg_summary("called\n");
@@ -841,16 +863,6 @@ int jffs2_sum_write_sumnode(struct jffs2_sb_info *c) 
	infosize += padsize;

	datasize += padsize;



	/* Is there enough space for summary? */

	if (padsize < 0) {

		/* don't try to write out summary for this jeb */

		jffs2_sum_disable_collecting(c->summary);



		JFFS2_WARNING("Not enough space for summary, padsize = %d\n", padsize);

		spin_lock(&c->erase_completion_lock);

		return 0;

	}



	ret = jffs2_sum_write_data(c, jeb, infosize, datasize, padsize);

	spin_lock(&c->erase_completion_lock);

	return ret;

fs/jffs2/summary.h

+6 −0
Original line number Diff line number Diff line
@@ -13,6 +13,12 @@ 
#ifndef JFFS2_SUMMARY_H

#define JFFS2_SUMMARY_H



/* Limit summary size to 64KiB so that we can kmalloc it. If the summary

   is larger than that, we have to just ditch it and avoid using summary

   for the eraseblock in question... and it probably doesn't hurt us much

   anyway. */

#define MAX_SUMMARY_SIZE 65536



#include <linux/uio.h>

#include <linux/jffs2.h>