[linux-2.6-block.git] / fs / jffs2 / build.c

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright (C) 2001-2003 Red Hat, Inc.
 *
 * Created by David Woodhouse <dwmw2@infradead.org>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 * $Id: build.c,v 1.83 2005/09/21 15:52:33 dedekind Exp $
 *
 */

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/mtd/mtd.h>
#include "nodelist.h"

static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *,
		struct jffs2_inode_cache *, struct jffs2_full_dirent **);

static inline struct jffs2_inode_cache *
first_inode_chain(int *i, struct jffs2_sb_info *c)
{
	for (; *i < INOCACHE_HASHSIZE; (*i)++) {
		if (c->inocache_list[*i])
			return c->inocache_list[*i];
	}
	return NULL;
}

static inline struct jffs2_inode_cache *
next_inode(int *i, struct jffs2_inode_cache *ic, struct jffs2_sb_info *c)
{
	/* More in this chain? */
	if (ic->next)
		return ic->next;
	(*i)++;
	return first_inode_chain(i, c);
}

#define for_each_inode(i, c, ic)			\
	for (i = 0, ic = first_inode_chain(&i, (c));	\
	     ic;					\
	     ic = next_inode(&i, ic, (c)))


static inline void jffs2_build_inode_pass1(struct jffs2_sb_info *c,
					struct jffs2_inode_cache *ic)
{
	struct jffs2_full_dirent *fd;

	dbg_fsbuild("building directory inode #%u\n", ic->ino);

	/* For each child, increase nlink */
	for(fd = ic->scan_dents; fd; fd = fd->next) {
		struct jffs2_inode_cache *child_ic;
		if (!fd->ino)
			continue;

		/* we can get high latency here with huge directories */

		child_ic = jffs2_get_ino_cache(c, fd->ino);
		if (!child_ic) {
			dbg_fsbuild("child \"%s\" (ino #%u) of dir ino #%u doesn't exist!\n",
				  fd->name, fd->ino, ic->ino);
			jffs2_mark_node_obsolete(c, fd->raw);
			continue;
		}

		if (child_ic->nlink++ && fd->type == DT_DIR) {
			JFFS2_ERROR("child dir \"%s\" (ino #%u) of dir ino #%u appears to be a hard link\n",
				fd->name, fd->ino, ic->ino);
			/* TODO: What do we do about it? */
		}
		dbg_fsbuild("increased nlink for child \"%s\" (ino #%u)\n", fd->name, fd->ino);
		/* Can't free scan_dents so far. We might need them in pass 2 */
	}
}

/* Scan plan:
 - Scan physical nodes. Build map of inodes/dirents. Allocate inocaches as we go
 - Scan directory tree from top down, setting nlink in inocaches
 - Scan inocaches for inodes with nlink==0
*/
static int jffs2_build_filesystem(struct jffs2_sb_info *c)
{
	int ret;
	int i;
	struct jffs2_inode_cache *ic;
	struct jffs2_full_dirent *fd;
	struct jffs2_full_dirent *dead_fds = NULL;

	dbg_fsbuild("build FS data structures\n");

	/* First, scan the medium and build all the inode caches with
	   lists of physical nodes */

	c->flags |= JFFS2_SB_FLAG_SCANNING;
	ret = jffs2_scan_medium(c);
	c->flags &= ~JFFS2_SB_FLAG_SCANNING;
	if (ret)
		goto exit;

	dbg_fsbuild("scanned flash completely\n");
	jffs2_dbg_dump_block_lists_nolock(c);

	dbg_fsbuild("pass 1 starting\n");
	c->flags |= JFFS2_SB_FLAG_BUILDING;
	/* Now scan the directory tree, increasing nlink according to every dirent found. */
	for_each_inode(i, c, ic) {
		if (ic->scan_dents) {
			jffs2_build_inode_pass1(c, ic);
			cond_resched();
		}
	}

	dbg_fsbuild("pass 1 complete\n");

	/* Next, scan for inodes with nlink == 0 and remove them. If
	   they were directories, then decrement the nlink of their
	   children too, and repeat the scan. As that's going to be
	   a fairly uncommon occurrence, it's not so evil to do it this
	   way. Recursion bad. */
	dbg_fsbuild("pass 2 starting\n");

	for_each_inode(i, c, ic) {
		if (ic->nlink)
			continue;
			
		jffs2_build_remove_unlinked_inode(c, ic, &dead_fds);
		cond_resched();
	} 

	dbg_fsbuild("pass 2a starting\n");

	while (dead_fds) {
		fd = dead_fds;
		dead_fds = fd->next;

		ic = jffs2_get_ino_cache(c, fd->ino);

		if (ic)
			jffs2_build_remove_unlinked_inode(c, ic, &dead_fds);
		jffs2_free_full_dirent(fd);
	}

	dbg_fsbuild("pass 2a complete\n");
	dbg_fsbuild("freeing temporary data structures\n");
	
	/* Finally, we can scan again and free the dirent structs */
	for_each_inode(i, c, ic) {
		while(ic->scan_dents) {
			fd = ic->scan_dents;
			ic->scan_dents = fd->next;
			jffs2_free_full_dirent(fd);
		}
		ic->scan_dents = NULL;
		cond_resched();
	}
	c->flags &= ~JFFS2_SB_FLAG_BUILDING;
	
	dbg_fsbuild("FS build complete\n");

	/* Rotate the lists by some number to ensure wear levelling */
	jffs2_rotate_lists(c);

	ret = 0;

exit:
	if (ret) {
		for_each_inode(i, c, ic) {
			while(ic->scan_dents) {
				fd = ic->scan_dents;
				ic->scan_dents = fd->next;
				jffs2_free_full_dirent(fd);
			}
		}
	}

	return ret;
}

static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *c,
					struct jffs2_inode_cache *ic,
					struct jffs2_full_dirent **dead_fds)
{
	struct jffs2_raw_node_ref *raw;
	struct jffs2_full_dirent *fd;

	dbg_fsbuild("removing ino #%u with nlink == zero.\n", ic->ino);
	
	raw = ic->nodes;
	while (raw != (void *)ic) {
		struct jffs2_raw_node_ref *next = raw->next_in_ino;
		dbg_fsbuild("obsoleting node at 0x%08x\n", ref_offset(raw));
		jffs2_mark_node_obsolete(c, raw);
		raw = next;
	}

	if (ic->scan_dents) {
		int whinged = 0;
		dbg_fsbuild("inode #%u was a directory which may have children...\n", ic->ino);

		while(ic->scan_dents) {
			struct jffs2_inode_cache *child_ic;

			fd = ic->scan_dents;
			ic->scan_dents = fd->next;

			if (!fd->ino) {
				/* It's a deletion dirent. Ignore it */
				dbg_fsbuild("child \"%s\" is a deletion dirent, skipping...\n", fd->name);
				jffs2_free_full_dirent(fd);
				continue;
			}
			if (!whinged)
				whinged = 1;

			dbg_fsbuild("removing child \"%s\", ino #%u\n", fd->name, fd->ino);
			
			child_ic = jffs2_get_ino_cache(c, fd->ino);
			if (!child_ic) {
				dbg_fsbuild("cannot remove child \"%s\", ino #%u, because it doesn't exist\n",
						fd->name, fd->ino);
				jffs2_free_full_dirent(fd);
				continue;
			}

			/* Reduce nlink of the child. If it's now zero, stick it on the 
			   dead_fds list to be cleaned up later. Else just free the fd */

			child_ic->nlink--;
			
			if (!child_ic->nlink) {
				dbg_fsbuild("inode #%u (\"%s\") has now got zero nlink, adding to dead_fds list.\n",
					  fd->ino, fd->name);
				fd->next = *dead_fds;
				*dead_fds = fd;
			} else {
				dbg_fsbuild("inode #%u (\"%s\") has now got nlink %d. Ignoring.\n",
					  fd->ino, fd->name, child_ic->nlink);
				jffs2_free_full_dirent(fd);
			}
		}
	}

	/*
	   We don't delete the inocache from the hash list and free it yet. 
	   The erase code will do that, when all the nodes are completely gone.
	*/
}

static void jffs2_calc_trigger_levels(struct jffs2_sb_info *c)
{
	uint32_t size;

	/* Deletion should almost _always_ be allowed. We're fairly
	   buggered once we stop allowing people to delete stuff
	   because there's not enough free space... */
	c->resv_blocks_deletion = 2;

	/* Be conservative about how much space we need before we allow writes. 
	   On top of that which is required for deletia, require an extra 2%
	   of the medium to be available, for overhead caused by nodes being
	   split across blocks, etc. */

	size = c->flash_size / 50; /* 2% of flash size */
	size += c->nr_blocks * 100; /* And 100 bytes per eraseblock */
	size += c->sector_size - 1; /* ... and round up */

	c->resv_blocks_write = c->resv_blocks_deletion + (size / c->sector_size);

	/* When do we let the GC thread run in the background */

	c->resv_blocks_gctrigger = c->resv_blocks_write + 1;

	/* When do we allow garbage collection to merge nodes to make 
	   long-term progress at the expense of short-term space exhaustion? */
	c->resv_blocks_gcmerge = c->resv_blocks_deletion + 1;

	/* When do we allow garbage collection to eat from bad blocks rather
	   than actually making progress? */
	c->resv_blocks_gcbad = 0;//c->resv_blocks_deletion + 2;

	/* If there's less than this amount of dirty space, don't bother
	   trying to GC to make more space. It'll be a fruitless task */
	c->nospc_dirty_size = c->sector_size + (c->flash_size / 100);

	dbg_fsbuild("JFFS2 trigger levels (size %d KiB, block size %d KiB, %d blocks)\n",
		  c->flash_size / 1024, c->sector_size / 1024, c->nr_blocks);
	dbg_fsbuild("Blocks required to allow deletion:    %d (%d KiB)\n",
		  c->resv_blocks_deletion, c->resv_blocks_deletion*c->sector_size/1024);
	dbg_fsbuild("Blocks required to allow writes:      %d (%d KiB)\n",
		  c->resv_blocks_write, c->resv_blocks_write*c->sector_size/1024);
	dbg_fsbuild("Blocks required to quiesce GC thread: %d (%d KiB)\n",
		  c->resv_blocks_gctrigger, c->resv_blocks_gctrigger*c->sector_size/1024);
	dbg_fsbuild("Blocks required to allow GC merges:   %d (%d KiB)\n",
		  c->resv_blocks_gcmerge, c->resv_blocks_gcmerge*c->sector_size/1024);
	dbg_fsbuild("Blocks required to GC bad blocks:     %d (%d KiB)\n",
		  c->resv_blocks_gcbad, c->resv_blocks_gcbad*c->sector_size/1024);
	dbg_fsbuild("Amount of dirty space required to GC: %d bytes\n",
		  c->nospc_dirty_size);
} 

int jffs2_do_mount_fs(struct jffs2_sb_info *c)
{
	int ret;
	int i;

	c->free_size = c->flash_size;
	c->nr_blocks = c->flash_size / c->sector_size;
#ifndef __ECOS
	if (jffs2_blocks_use_vmalloc(c))
		c->blocks = vmalloc(sizeof(struct jffs2_eraseblock) * c->nr_blocks);
	else
#endif
		c->blocks = kmalloc(sizeof(struct jffs2_eraseblock) * c->nr_blocks, GFP_KERNEL);
	if (!c->blocks)
		return -ENOMEM;
	for (i=0; i<c->nr_blocks; i++) {
		INIT_LIST_HEAD(&c->blocks[i].list);
		c->blocks[i].offset = i * c->sector_size;
		c->blocks[i].free_size = c->sector_size;
		c->blocks[i].dirty_size = 0;
		c->blocks[i].wasted_size = 0;
		c->blocks[i].unchecked_size = 0;
		c->blocks[i].used_size = 0;
		c->blocks[i].first_node = NULL;
		c->blocks[i].last_node = NULL;
		c->blocks[i].bad_count = 0;
	}

	INIT_LIST_HEAD(&c->clean_list);
	INIT_LIST_HEAD(&c->very_dirty_list);
	INIT_LIST_HEAD(&c->dirty_list);
	INIT_LIST_HEAD(&c->erasable_list);
	INIT_LIST_HEAD(&c->erasing_list);
	INIT_LIST_HEAD(&c->erase_pending_list);
	INIT_LIST_HEAD(&c->erasable_pending_wbuf_list);
	INIT_LIST_HEAD(&c->erase_complete_list);
	INIT_LIST_HEAD(&c->free_list);
	INIT_LIST_HEAD(&c->bad_list);
	INIT_LIST_HEAD(&c->bad_used_list);
	c->highest_ino = 1;
	c->summary = NULL;

	ret = jffs2_sum_init(c);
	if (ret)
		return ret;

	if (jffs2_build_filesystem(c)) {
		dbg_fsbuild("build_fs failed\n");
		jffs2_free_ino_caches(c);
		jffs2_free_raw_node_refs(c);
#ifndef __ECOS
		if (jffs2_blocks_use_vmalloc(c))
			vfree(c->blocks);
		else 
#endif
			kfree(c->blocks);

		return -EIO;
	}

	jffs2_calc_trigger_levels(c);

	return 0;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* JFFS2 -- Journalling Flash File System, Version 2.
	3	*
	4	* Copyright (C) 2001-2003 Red Hat, Inc.
	5	*
	6	* Created by David Woodhouse <dwmw2@infradead.org>
	7	*
	8	* For licensing information, see the file 'LICENCE' in this directory.
	9	*
733802d9	10	* $Id: build.c,v 1.83 2005/09/21 15:52:33 dedekind Exp $
1da177e4 LT	11	*
	12	*/
	13
	14	#include <linux/kernel.h>
	15	#include <linux/sched.h>
	16	#include <linux/slab.h>
	17	#include <linux/vmalloc.h>
	18	#include <linux/mtd/mtd.h>
	19	#include "nodelist.h"
	20
733802d9 AB	21	static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *,
733802d9 AB	22	struct jffs2_inode_cache , struct jffs2_full_dirent *);
1da177e4 LT	23
	24	static inline struct jffs2_inode_cache *
	25	first_inode_chain(int i, struct jffs2_sb_info c)
	26	{
	27	for (; i < INOCACHE_HASHSIZE; (i)++) {
	28	if (c->inocache_list[*i])
	29	return c->inocache_list[*i];
	30	}
	31	return NULL;
	32	}
	33
	34	static inline struct jffs2_inode_cache *
	35	next_inode(int i, struct jffs2_inode_cache ic, struct jffs2_sb_info *c)
	36	{
	37	/* More in this chain? */
	38	if (ic->next)
	39	return ic->next;
	40	(*i)++;
	41	return first_inode_chain(i, c);
	42	}
	43
	44	#define for_each_inode(i, c, ic) \
	45	for (i = 0, ic = first_inode_chain(&i, (c)); \
	46	ic; \
	47	ic = next_inode(&i, ic, (c)))
	48
	49
733802d9 AB	50	static inline void jffs2_build_inode_pass1(struct jffs2_sb_info *c,
733802d9 AB	51	struct jffs2_inode_cache *ic)
1da177e4 LT	52	{
	53	struct jffs2_full_dirent *fd;
	54
733802d9	55	dbg_fsbuild("building directory inode #%u\n", ic->ino);
1da177e4 LT	56
	57	/* For each child, increase nlink */
	58	for(fd = ic->scan_dents; fd; fd = fd->next) {
	59	struct jffs2_inode_cache *child_ic;
	60	if (!fd->ino)
	61	continue;
	62
733802d9	63	/* we can get high latency here with huge directories */
1da177e4 LT	64
	65	child_ic = jffs2_get_ino_cache(c, fd->ino);
	66	if (!child_ic) {
733802d9	67	dbg_fsbuild("child \"%s\" (ino #%u) of dir ino #%u doesn't exist!\n",
1da177e4 LT	68	fd->name, fd->ino, ic->ino);
	69	jffs2_mark_node_obsolete(c, fd->raw);
	70	continue;
	71	}
	72
	73	if (child_ic->nlink++ && fd->type == DT_DIR) {
733802d9 AB	74	JFFS2_ERROR("child dir \"%s\" (ino #%u) of dir ino #%u appears to be a hard link\n",
	75	fd->name, fd->ino, ic->ino);
	76	/* TODO: What do we do about it? */
1da177e4	77	}
733802d9 AB	78	dbg_fsbuild("increased nlink for child \"%s\" (ino #%u)\n", fd->name, fd->ino);
733802d9 AB	79	/* Can't free scan_dents so far. We might need them in pass 2 */
1da177e4 LT	80	}
	81	}
	82
	83	/* Scan plan:
	84	- Scan physical nodes. Build map of inodes/dirents. Allocate inocaches as we go
	85	- Scan directory tree from top down, setting nlink in inocaches
	86	- Scan inocaches for inodes with nlink==0
	87	*/
	88	static int jffs2_build_filesystem(struct jffs2_sb_info *c)
	89	{
	90	int ret;
	91	int i;
	92	struct jffs2_inode_cache *ic;
	93	struct jffs2_full_dirent *fd;
	94	struct jffs2_full_dirent *dead_fds = NULL;
	95
733802d9 AB	96	dbg_fsbuild("build FS data structures\n");
733802d9 AB	97
1da177e4 LT	98	/* First, scan the medium and build all the inode caches with
	99	lists of physical nodes */
	100
31fbdf7a	101	c->flags \|= JFFS2_SB_FLAG_SCANNING;
1da177e4	102	ret = jffs2_scan_medium(c);
31fbdf7a	103	c->flags &= ~JFFS2_SB_FLAG_SCANNING;
1da177e4 LT	104	if (ret)
	105	goto exit;
	106
733802d9	107	dbg_fsbuild("scanned flash completely\n");
e0c8e42f	108	jffs2_dbg_dump_block_lists_nolock(c);
1da177e4	109
733802d9	110	dbg_fsbuild("pass 1 starting\n");
31fbdf7a	111	c->flags \|= JFFS2_SB_FLAG_BUILDING;
1da177e4 LT	112	/* Now scan the directory tree, increasing nlink according to every dirent found. */
1da177e4 LT	113	for_each_inode(i, c, ic) {
1da177e4 LT	114	if (ic->scan_dents) {
	115	jffs2_build_inode_pass1(c, ic);
	116	cond_resched();
	117	}
	118	}
1da177e4	119
733802d9	120	dbg_fsbuild("pass 1 complete\n");
1da177e4 LT	121
	122	/* Next, scan for inodes with nlink == 0 and remove them. If
	123	they were directories, then decrement the nlink of their
	124	children too, and repeat the scan. As that's going to be
	125	a fairly uncommon occurrence, it's not so evil to do it this
	126	way. Recursion bad. */
733802d9	127	dbg_fsbuild("pass 2 starting\n");
1da177e4 LT	128
1da177e4 LT	129	for_each_inode(i, c, ic) {
1da177e4 LT	130	if (ic->nlink)
	131	continue;
	132
	133	jffs2_build_remove_unlinked_inode(c, ic, &dead_fds);
	134	cond_resched();
	135	}
	136
733802d9	137	dbg_fsbuild("pass 2a starting\n");
1da177e4 LT	138
	139	while (dead_fds) {
	140	fd = dead_fds;
	141	dead_fds = fd->next;
	142
	143	ic = jffs2_get_ino_cache(c, fd->ino);
1da177e4 LT	144
	145	if (ic)
	146	jffs2_build_remove_unlinked_inode(c, ic, &dead_fds);
	147	jffs2_free_full_dirent(fd);
	148	}
	149
733802d9 AB	150	dbg_fsbuild("pass 2a complete\n");
733802d9 AB	151	dbg_fsbuild("freeing temporary data structures\n");
1da177e4 LT	152
	153	/* Finally, we can scan again and free the dirent structs */
	154	for_each_inode(i, c, ic) {
1da177e4 LT	155	while(ic->scan_dents) {
	156	fd = ic->scan_dents;
	157	ic->scan_dents = fd->next;
	158	jffs2_free_full_dirent(fd);
	159	}
	160	ic->scan_dents = NULL;
	161	cond_resched();
	162	}
31fbdf7a AB	163	c->flags &= ~JFFS2_SB_FLAG_BUILDING;
31fbdf7a AB	164
733802d9	165	dbg_fsbuild("FS build complete\n");
1da177e4 LT	166
	167	/* Rotate the lists by some number to ensure wear levelling */
	168	jffs2_rotate_lists(c);
	169
	170	ret = 0;
	171
	172	exit:
	173	if (ret) {
	174	for_each_inode(i, c, ic) {
	175	while(ic->scan_dents) {
	176	fd = ic->scan_dents;
	177	ic->scan_dents = fd->next;
	178	jffs2_free_full_dirent(fd);
	179	}
	180	}
	181	}
	182
	183	return ret;
	184	}
	185
733802d9 AB	186	static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *c,
	187	struct jffs2_inode_cache *ic,
	188	struct jffs2_full_dirent **dead_fds)
1da177e4 LT	189	{
	190	struct jffs2_raw_node_ref *raw;
	191	struct jffs2_full_dirent *fd;
	192
733802d9	193	dbg_fsbuild("removing ino #%u with nlink == zero.\n", ic->ino);
1da177e4 LT	194
	195	raw = ic->nodes;
	196	while (raw != (void *)ic) {
	197	struct jffs2_raw_node_ref *next = raw->next_in_ino;
733802d9	198	dbg_fsbuild("obsoleting node at 0x%08x\n", ref_offset(raw));
1da177e4 LT	199	jffs2_mark_node_obsolete(c, raw);
	200	raw = next;
	201	}
	202
	203	if (ic->scan_dents) {
	204	int whinged = 0;
733802d9	205	dbg_fsbuild("inode #%u was a directory which may have children...\n", ic->ino);
1da177e4 LT	206
	207	while(ic->scan_dents) {
	208	struct jffs2_inode_cache *child_ic;
	209
	210	fd = ic->scan_dents;
	211	ic->scan_dents = fd->next;
	212
	213	if (!fd->ino) {
	214	/* It's a deletion dirent. Ignore it */
733802d9	215	dbg_fsbuild("child \"%s\" is a deletion dirent, skipping...\n", fd->name);
1da177e4 LT	216	jffs2_free_full_dirent(fd);
	217	continue;
	218	}
733802d9	219	if (!whinged)
1da177e4	220	whinged = 1;
1da177e4	221
733802d9	222	dbg_fsbuild("removing child \"%s\", ino #%u\n", fd->name, fd->ino);
1da177e4 LT	223
	224	child_ic = jffs2_get_ino_cache(c, fd->ino);
	225	if (!child_ic) {
733802d9 AB	226	dbg_fsbuild("cannot remove child \"%s\", ino #%u, because it doesn't exist\n",
733802d9 AB	227	fd->name, fd->ino);
1da177e4 LT	228	jffs2_free_full_dirent(fd);
	229	continue;
	230	}
	231
	232	/* Reduce nlink of the child. If it's now zero, stick it on the
	233	dead_fds list to be cleaned up later. Else just free the fd */
	234
	235	child_ic->nlink--;
	236
	237	if (!child_ic->nlink) {
733802d9 AB	238	dbg_fsbuild("inode #%u (\"%s\") has now got zero nlink, adding to dead_fds list.\n",
733802d9 AB	239	fd->ino, fd->name);
1da177e4 LT	240	fd->next = *dead_fds;
	241	*dead_fds = fd;
	242	} else {
733802d9 AB	243	dbg_fsbuild("inode #%u (\"%s\") has now got nlink %d. Ignoring.\n",
733802d9 AB	244	fd->ino, fd->name, child_ic->nlink);
1da177e4 LT	245	jffs2_free_full_dirent(fd);
	246	}
	247	}
	248	}
	249
	250	/*
	251	We don't delete the inocache from the hash list and free it yet.
	252	The erase code will do that, when all the nodes are completely gone.
	253	*/
	254	}
	255
	256	static void jffs2_calc_trigger_levels(struct jffs2_sb_info *c)
	257	{
	258	uint32_t size;
	259
	260	/* Deletion should almost _always_ be allowed. We're fairly
	261	buggered once we stop allowing people to delete stuff
	262	because there's not enough free space... */
	263	c->resv_blocks_deletion = 2;
	264
	265	/* Be conservative about how much space we need before we allow writes.
	266	On top of that which is required for deletia, require an extra 2%
	267	of the medium to be available, for overhead caused by nodes being
	268	split across blocks, etc. */
	269
	270	size = c->flash_size / 50; /* 2% of flash size */
	271	size += c->nr_blocks * 100; /* And 100 bytes per eraseblock */
	272	size += c->sector_size - 1; /* ... and round up */
	273
	274	c->resv_blocks_write = c->resv_blocks_deletion + (size / c->sector_size);
	275
	276	/* When do we let the GC thread run in the background */
	277
	278	c->resv_blocks_gctrigger = c->resv_blocks_write + 1;
	279
	280	/* When do we allow garbage collection to merge nodes to make
	281	long-term progress at the expense of short-term space exhaustion? */
	282	c->resv_blocks_gcmerge = c->resv_blocks_deletion + 1;
	283
	284	/* When do we allow garbage collection to eat from bad blocks rather
	285	than actually making progress? */
	286	c->resv_blocks_gcbad = 0;//c->resv_blocks_deletion + 2;
	287
	288	/* If there's less than this amount of dirty space, don't bother
	289	trying to GC to make more space. It'll be a fruitless task */
	290	c->nospc_dirty_size = c->sector_size + (c->flash_size / 100);
	291
733802d9 AB	292	dbg_fsbuild("JFFS2 trigger levels (size %d KiB, block size %d KiB, %d blocks)\n",
	293	c->flash_size / 1024, c->sector_size / 1024, c->nr_blocks);
	294	dbg_fsbuild("Blocks required to allow deletion: %d (%d KiB)\n",
	295	c->resv_blocks_deletion, c->resv_blocks_deletion*c->sector_size/1024);
	296	dbg_fsbuild("Blocks required to allow writes: %d (%d KiB)\n",
	297	c->resv_blocks_write, c->resv_blocks_write*c->sector_size/1024);
	298	dbg_fsbuild("Blocks required to quiesce GC thread: %d (%d KiB)\n",
	299	c->resv_blocks_gctrigger, c->resv_blocks_gctrigger*c->sector_size/1024);
	300	dbg_fsbuild("Blocks required to allow GC merges: %d (%d KiB)\n",
	301	c->resv_blocks_gcmerge, c->resv_blocks_gcmerge*c->sector_size/1024);
	302	dbg_fsbuild("Blocks required to GC bad blocks: %d (%d KiB)\n",
	303	c->resv_blocks_gcbad, c->resv_blocks_gcbad*c->sector_size/1024);
	304	dbg_fsbuild("Amount of dirty space required to GC: %d bytes\n",
	305	c->nospc_dirty_size);
1da177e4 LT	306	}
	307
	308	int jffs2_do_mount_fs(struct jffs2_sb_info *c)
	309	{
c617e842	310	int ret;
1da177e4 LT	311	int i;
	312
	313	c->free_size = c->flash_size;
	314	c->nr_blocks = c->flash_size / c->sector_size;
737b7661	315	#ifndef __ECOS
4ce1f562	316	if (jffs2_blocks_use_vmalloc(c))
1da177e4 LT	317	c->blocks = vmalloc(sizeof(struct jffs2_eraseblock) * c->nr_blocks);
1da177e4 LT	318	else
737b7661	319	#endif
1da177e4 LT	320	c->blocks = kmalloc(sizeof(struct jffs2_eraseblock) * c->nr_blocks, GFP_KERNEL);
	321	if (!c->blocks)
	322	return -ENOMEM;
	323	for (i=0; i<c->nr_blocks; i++) {
	324	INIT_LIST_HEAD(&c->blocks[i].list);
	325	c->blocks[i].offset = i * c->sector_size;
	326	c->blocks[i].free_size = c->sector_size;
	327	c->blocks[i].dirty_size = 0;
	328	c->blocks[i].wasted_size = 0;
	329	c->blocks[i].unchecked_size = 0;
	330	c->blocks[i].used_size = 0;
	331	c->blocks[i].first_node = NULL;
	332	c->blocks[i].last_node = NULL;
	333	c->blocks[i].bad_count = 0;
	334	}
	335
1da177e4 LT	336	INIT_LIST_HEAD(&c->clean_list);
	337	INIT_LIST_HEAD(&c->very_dirty_list);
	338	INIT_LIST_HEAD(&c->dirty_list);
	339	INIT_LIST_HEAD(&c->erasable_list);
	340	INIT_LIST_HEAD(&c->erasing_list);
	341	INIT_LIST_HEAD(&c->erase_pending_list);
	342	INIT_LIST_HEAD(&c->erasable_pending_wbuf_list);
	343	INIT_LIST_HEAD(&c->erase_complete_list);
	344	INIT_LIST_HEAD(&c->free_list);
	345	INIT_LIST_HEAD(&c->bad_list);
	346	INIT_LIST_HEAD(&c->bad_used_list);
	347	c->highest_ino = 1;
e631ddba FH	348	c->summary = NULL;
e631ddba FH	349
c617e842 FH	350	ret = jffs2_sum_init(c);
	351	if (ret)
	352	return ret;
1da177e4 LT	353
1da177e4 LT	354	if (jffs2_build_filesystem(c)) {
733802d9	355	dbg_fsbuild("build_fs failed\n");
1da177e4 LT	356	jffs2_free_ino_caches(c);
1da177e4 LT	357	jffs2_free_raw_node_refs(c);
737b7661	358	#ifndef __ECOS
4ce1f562	359	if (jffs2_blocks_use_vmalloc(c))
e631ddba	360	vfree(c->blocks);
737b7661 AL	361	else
737b7661 AL	362	#endif
e631ddba FH	363	kfree(c->blocks);
e631ddba FH	364
1da177e4 LT	365	return -EIO;
	366	}
	367
	368	jffs2_calc_trigger_levels(c);
	369
	370	return 0;
	371	}