summary.c

linux 内核源代码

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2004  Ferenc Havasi <[e-mail]>,
 *		     Zoltan Sogor <[e-mail]>,
 *		     Patrik Kluba <[e-mail]>,
 *		     University of Szeged, Hungary
 *	       2006  KaiGai Kohei <[e-mail]>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/pagemap.h>
#include <linux/crc32.h>
#include <linux/compiler.h>
#include <linux/vmalloc.h>
#include "nodelist.h"
#include "debug.h"

int jffs2_sum_init(struct jffs2_sb_info *c)
{
	c->summary = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL);

	if (!c->summary) {
		JFFS2_WARNING("Can't allocate memory for summary information!\n");
		return -ENOMEM;
	}

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

	if (!c->summary->sum_buf) {
		JFFS2_WARNING("Can't allocate buffer for writing out summary information!\n");
		kfree(c->summary);
		return -ENOMEM;
	}

	dbg_summary("returned successfully\n");

	return 0;
}

void jffs2_sum_exit(struct jffs2_sb_info *c)
{
	dbg_summary("called\n");

	jffs2_sum_disable_collecting(c->summary);

	vfree(c->summary->sum_buf);
	c->summary->sum_buf = NULL;

	kfree(c->summary);
	c->summary = NULL;
}

static int jffs2_sum_add_mem(struct jffs2_summary *s, union jffs2_sum_mem *item)
{
	if (!s->sum_list_head)
		s->sum_list_head = (union jffs2_sum_mem *) item;
	if (s->sum_list_tail)
		s->sum_list_tail->u.next = (union jffs2_sum_mem *) item;
	s->sum_list_tail = (union jffs2_sum_mem *) item;

	switch (je16_to_cpu(item->u.nodetype)) {
		case JFFS2_NODETYPE_INODE:
			s->sum_size += JFFS2_SUMMARY_INODE_SIZE;
			s->sum_num++;
			dbg_summary("inode (%u) added to summary\n",
						je32_to_cpu(item->i.inode));
			break;
		case JFFS2_NODETYPE_DIRENT:
			s->sum_size += JFFS2_SUMMARY_DIRENT_SIZE(item->d.nsize);
			s->sum_num++;
			dbg_summary("dirent (%u) added to summary\n",
						je32_to_cpu(item->d.ino));
			break;
#ifdef CONFIG_JFFS2_FS_XATTR
		case JFFS2_NODETYPE_XATTR:
			s->sum_size += JFFS2_SUMMARY_XATTR_SIZE;
			s->sum_num++;
			dbg_summary("xattr (xid=%u, version=%u) added to summary\n",
				    je32_to_cpu(item->x.xid), je32_to_cpu(item->x.version));
			break;
		case JFFS2_NODETYPE_XREF:
			s->sum_size += JFFS2_SUMMARY_XREF_SIZE;
			s->sum_num++;
			dbg_summary("xref added to summary\n");
			break;
#endif
		default:
			JFFS2_WARNING("UNKNOWN node type %u\n",
					    je16_to_cpu(item->u.nodetype));
			return 1;
	}
	return 0;
}


/* The following 3 functions are called from scan.c to collect summary info for not closed jeb */

int jffs2_sum_add_padding_mem(struct jffs2_summary *s, uint32_t size)
{
	dbg_summary("called with %u\n", size);
	s->sum_padded += size;
	return 0;
}

int jffs2_sum_add_inode_mem(struct jffs2_summary *s, struct jffs2_raw_inode *ri,
				uint32_t ofs)
{
	struct jffs2_sum_inode_mem *temp = kmalloc(sizeof(struct jffs2_sum_inode_mem), GFP_KERNEL);

	if (!temp)
		return -ENOMEM;

	temp->nodetype = ri->nodetype;
	temp->inode = ri->ino;
	temp->version = ri->version;
	temp->offset = cpu_to_je32(ofs); /* relative offset from the begining of the jeb */
	temp->totlen = ri->totlen;
	temp->next = NULL;

	return jffs2_sum_add_mem(s, (union jffs2_sum_mem *)temp);
}

int jffs2_sum_add_dirent_mem(struct jffs2_summary *s, struct jffs2_raw_dirent *rd,
				uint32_t ofs)
{
	struct jffs2_sum_dirent_mem *temp =
		kmalloc(sizeof(struct jffs2_sum_dirent_mem) + rd->nsize, GFP_KERNEL);

	if (!temp)
		return -ENOMEM;

	temp->nodetype = rd->nodetype;
	temp->totlen = rd->totlen;
	temp->offset = cpu_to_je32(ofs);	/* relative from the begining of the jeb */
	temp->pino = rd->pino;
	temp->version = rd->version;
	temp->ino = rd->ino;
	temp->nsize = rd->nsize;
	temp->type = rd->type;
	temp->next = NULL;

	memcpy(temp->name, rd->name, rd->nsize);

	return jffs2_sum_add_mem(s, (union jffs2_sum_mem *)temp);
}

#ifdef CONFIG_JFFS2_FS_XATTR
int jffs2_sum_add_xattr_mem(struct jffs2_summary *s, struct jffs2_raw_xattr *rx, uint32_t ofs)
{
	struct jffs2_sum_xattr_mem *temp;

	temp = kmalloc(sizeof(struct jffs2_sum_xattr_mem), GFP_KERNEL);
	if (!temp)
		return -ENOMEM;

	temp->nodetype = rx->nodetype;
	temp->xid = rx->xid;
	temp->version = rx->version;
	temp->offset = cpu_to_je32(ofs);
	temp->totlen = rx->totlen;
	temp->next = NULL;

	return jffs2_sum_add_mem(s, (union jffs2_sum_mem *)temp);
}

int jffs2_sum_add_xref_mem(struct jffs2_summary *s, struct jffs2_raw_xref *rr, uint32_t ofs)
{
	struct jffs2_sum_xref_mem *temp;

	temp = kmalloc(sizeof(struct jffs2_sum_xref_mem), GFP_KERNEL);
	if (!temp)
		return -ENOMEM;

	temp->nodetype = rr->nodetype;
	temp->offset = cpu_to_je32(ofs);
	temp->next = NULL;

	return jffs2_sum_add_mem(s, (union jffs2_sum_mem *)temp);
}
#endif
/* Cleanup every collected summary information */

static void jffs2_sum_clean_collected(struct jffs2_summary *s)
{
	union jffs2_sum_mem *temp;

	if (!s->sum_list_head) {
		dbg_summary("already empty\n");
	}
	while (s->sum_list_head) {
		temp = s->sum_list_head;
		s->sum_list_head = s->sum_list_head->u.next;
		kfree(temp);
	}
	s->sum_list_tail = NULL;
	s->sum_padded = 0;
	s->sum_num = 0;
}

void jffs2_sum_reset_collected(struct jffs2_summary *s)
{
	dbg_summary("called\n");
	jffs2_sum_clean_collected(s);
	s->sum_size = 0;
}

void jffs2_sum_disable_collecting(struct jffs2_summary *s)
{
	dbg_summary("called\n");
	jffs2_sum_clean_collected(s);
	s->sum_size = JFFS2_SUMMARY_NOSUM_SIZE;
}

int jffs2_sum_is_disabled(struct jffs2_summary *s)
{
	return (s->sum_size == JFFS2_SUMMARY_NOSUM_SIZE);
}

/* Move the collected summary information into sb (called from scan.c) */

void jffs2_sum_move_collected(struct jffs2_sb_info *c, struct jffs2_summary *s)
{
	dbg_summary("oldsize=0x%x oldnum=%u => newsize=0x%x newnum=%u\n",
				c->summary->sum_size, c->summary->sum_num,
				s->sum_size, s->sum_num);

	c->summary->sum_size = s->sum_size;
	c->summary->sum_num = s->sum_num;
	c->summary->sum_padded = s->sum_padded;
	c->summary->sum_list_head = s->sum_list_head;
	c->summary->sum_list_tail = s->sum_list_tail;

	s->sum_list_head = s->sum_list_tail = NULL;
}

/* Called from wbuf.c to collect writed node info */

int jffs2_sum_add_kvec(struct jffs2_sb_info *c, const struct kvec *invecs,
				unsigned long count, uint32_t ofs)
{
	union jffs2_node_union *node;
	struct jffs2_eraseblock *jeb;

	if (c->summary->sum_size == JFFS2_SUMMARY_NOSUM_SIZE) {
		dbg_summary("Summary is disabled for this jeb! Skipping summary info!\n");
		return 0;
	}

	node = invecs[0].iov_base;
	jeb = &c->blocks[ofs / c->sector_size];
	ofs -= jeb->offset;

	switch (je16_to_cpu(node->u.nodetype)) {
		case JFFS2_NODETYPE_INODE: {
			struct jffs2_sum_inode_mem *temp =
				kmalloc(sizeof(struct jffs2_sum_inode_mem), GFP_KERNEL);

			if (!temp)
				goto no_mem;

			temp->nodetype = node->i.nodetype;
			temp->inode = node->i.ino;
			temp->version = node->i.version;
			temp->offset = cpu_to_je32(ofs);
			temp->totlen = node->i.totlen;
			temp->next = NULL;

			return jffs2_sum_add_mem(c->summary, (union jffs2_sum_mem *)temp);
		}

		case JFFS2_NODETYPE_DIRENT: {
			struct jffs2_sum_dirent_mem *temp =
				kmalloc(sizeof(struct jffs2_sum_dirent_mem) + node->d.nsize, GFP_KERNEL);

			if (!temp)
				goto no_mem;

			temp->nodetype = node->d.nodetype;
			temp->totlen = node->d.totlen;
			temp->offset = cpu_to_je32(ofs);
			temp->pino = node->d.pino;
			temp->version = node->d.version;
			temp->ino = node->d.ino;
			temp->nsize = node->d.nsize;
			temp->type = node->d.type;
			temp->next = NULL;

			switch (count) {
				case 1:
					memcpy(temp->name,node->d.name,node->d.nsize);
					break;

				case 2:
					memcpy(temp->name,invecs[1].iov_base,node->d.nsize);
					break;

				default:
					BUG();	/* impossible count value */
					break;
			}

			return jffs2_sum_add_mem(c->summary, (union jffs2_sum_mem *)temp);
		}
#ifdef CONFIG_JFFS2_FS_XATTR
		case JFFS2_NODETYPE_XATTR: {
			struct jffs2_sum_xattr_mem *temp;
			temp = kmalloc(sizeof(struct jffs2_sum_xattr_mem), GFP_KERNEL);
			if (!temp)
				goto no_mem;

			temp->nodetype = node->x.nodetype;
			temp->xid = node->x.xid;
			temp->version = node->x.version;
			temp->totlen = node->x.totlen;
			temp->offset = cpu_to_je32(ofs);
			temp->next = NULL;

			return jffs2_sum_add_mem(c->summary, (union jffs2_sum_mem *)temp);
		}
		case JFFS2_NODETYPE_XREF: {
			struct jffs2_sum_xref_mem *temp;
			temp = kmalloc(sizeof(struct jffs2_sum_xref_mem), GFP_KERNEL);
			if (!temp)
				goto no_mem;
			temp->nodetype = node->r.nodetype;
			temp->offset = cpu_to_je32(ofs);
			temp->next = NULL;

			return jffs2_sum_add_mem(c->summary, (union jffs2_sum_mem *)temp);
		}
#endif
		case JFFS2_NODETYPE_PADDING:
			dbg_summary("node PADDING\n");
			c->summary->sum_padded += je32_to_cpu(node->u.totlen);
			break;

		case JFFS2_NODETYPE_CLEANMARKER:
			dbg_summary("node CLEANMARKER\n");
			break;

		case JFFS2_NODETYPE_SUMMARY:
			dbg_summary("node SUMMARY\n");
			break;

		default:
			/* If you implement a new node type you should also implement
			   summary support for it or disable summary.
			*/
			BUG();
			break;
	}

	return 0;

no_mem:
	JFFS2_WARNING("MEMORY ALLOCATION ERROR!");
	return -ENOMEM;
}

static struct jffs2_raw_node_ref *sum_link_node_ref(struct jffs2_sb_info *c,
						    struct jffs2_eraseblock *jeb,
						    uint32_t ofs, uint32_t len,
						    struct jffs2_inode_cache *ic)
{
	/* If there was a gap, mark it dirty */
	if ((ofs & ~3) > c->sector_size - jeb->free_size) {
		/* Ew. Summary doesn't actually tell us explicitly about dirty space */
		jffs2_scan_dirty_space(c, jeb, (ofs & ~3) - (c->sector_size - jeb->free_size));
	}

	return jffs2_link_node_ref(c, jeb, jeb->offset + ofs, len, ic);
}

/* Process the stored summary information - helper function for jffs2_sum_scan_sumnode() */

static int jffs2_sum_process_sum_data(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
				struct jffs2_raw_summary *summary, uint32_t *pseudo_random)
{
	struct jffs2_inode_cache *ic;
	struct jffs2_full_dirent *fd;
	void *sp;
	int i, ino;
	int err;

	sp = summary->sum;

	for (i=0; i<je32_to_cpu(summary->sum_num); i++) {
		dbg_summary("processing summary index %d\n", i);

		cond_resched();

		/* Make sure there's a spare ref for dirty space */
		err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
		if (err)
			return err;

		switch (je16_to_cpu(((struct jffs2_sum_unknown_flash *)sp)->nodetype)) {
			case JFFS2_NODETYPE_INODE: {
				struct jffs2_sum_inode_flash *spi;
				spi = sp;

				ino = je32_to_cpu(spi->inode);

				dbg_summary("Inode at 0x%08x-0x%08x\n",
					    jeb->offset + je32_to_cpu(spi->offset),
					    jeb->offset + je32_to_cpu(spi->offset) + je32_to_cpu(spi->totlen));

				ic = jffs2_scan_make_ino_cache(c, ino);
				if (!ic) {
					JFFS2_NOTICE("scan_make_ino_cache failed\n");
					return -ENOMEM;
				}

				sum_link_node_ref(c, jeb, je32_to_cpu(spi->offset) | REF_UNCHECKED,
						  PAD(je32_to_cpu(spi->totlen)), ic);

				*pseudo_random += je32_to_cpu(spi->version);

				sp += JFFS2_SUMMARY_INODE_SIZE;

				break;
			}