fs/jffs2/scan.c

Source file repositories/reference/linux-study-clean/fs/jffs2/scan.c

File Facts

System
Linux kernel
Corpus path
fs/jffs2/scan.c
Extension
.c
Size
36199 bytes
Lines
1185
Domain
Core OS
Bucket
VFS And Filesystem Core
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) {
	if (sector_size < DEFAULT_EMPTY_SCAN_SIZE)
		return sector_size;
	else
		return DEFAULT_EMPTY_SCAN_SIZE;
}

static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
{
	int ret;

	if ((ret = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
		return ret;
	if ((ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size)))
		return ret;
	/* Turned wasted size into dirty, since we apparently 
	   think it's recoverable now. */
	jeb->dirty_size += jeb->wasted_size;
	c->dirty_size += jeb->wasted_size;
	c->wasted_size -= jeb->wasted_size;
	jeb->wasted_size = 0;
	if (VERYDIRTY(c, jeb->dirty_size)) {
		list_add(&jeb->list, &c->very_dirty_list);
	} else {
		list_add(&jeb->list, &c->dirty_list);
	}
	return 0;
}

int jffs2_scan_medium(struct jffs2_sb_info *c)
{
	int i, ret;
	uint32_t empty_blocks = 0, bad_blocks = 0;
	unsigned char *flashbuf = NULL;
	uint32_t buf_size = 0;
	struct jffs2_summary *s = NULL; /* summary info collected by the scan process */
#ifndef __ECOS
	size_t pointlen, try_size;

	ret = mtd_point(c->mtd, 0, c->mtd->size, &pointlen,
			(void **)&flashbuf, NULL);
	if (!ret && pointlen < c->mtd->size) {
		/* Don't muck about if it won't let us point to the whole flash */
		jffs2_dbg(1, "MTD point returned len too short: 0x%zx\n",
			  pointlen);
		mtd_unpoint(c->mtd, 0, pointlen);
		flashbuf = NULL;
	}
	if (ret && ret != -EOPNOTSUPP)
		jffs2_dbg(1, "MTD point failed %d\n", ret);
#endif
	if (!flashbuf) {
		/* For NAND it's quicker to read a whole eraseblock at a time,
		   apparently */
		if (jffs2_cleanmarker_oob(c))
			try_size = c->sector_size;
		else
			try_size = PAGE_SIZE;

		jffs2_dbg(1, "Trying to allocate readbuf of %zu "
			  "bytes\n", try_size);

		flashbuf = mtd_kmalloc_up_to(c->mtd, &try_size);
		if (!flashbuf)
			return -ENOMEM;

		jffs2_dbg(1, "Allocated readbuf of %zu bytes\n",
			  try_size);

		buf_size = (uint32_t)try_size;
	}

	if (jffs2_sum_active()) {
		s = kzalloc_obj(struct jffs2_summary);
		if (!s) {
			JFFS2_WARNING("Can't allocate memory for summary\n");
			ret = -ENOMEM;
			goto out_buf;
		}
	}

	for (i=0; i<c->nr_blocks; i++) {
		struct jffs2_eraseblock *jeb = &c->blocks[i];

		cond_resched();

		/* reset summary info for next eraseblock scan */
		jffs2_sum_reset_collected(s);

		ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),

Annotation

Implementation Notes