fs.c

linux 内核源代码

	jffs2_do_setattr(inode, &iattr);
}

int jffs2_remount_fs (struct super_block *sb, int *flags, char *data)
{
	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);

	if (c->flags & JFFS2_SB_FLAG_RO && !(sb->s_flags & MS_RDONLY))
		return -EROFS;

	/* We stop if it was running, then restart if it needs to.
	   This also catches the case where it was stopped and this
	   is just a remount to restart it.
	   Flush the writebuffer, if neccecary, else we loose it */
	if (!(sb->s_flags & MS_RDONLY)) {
		jffs2_stop_garbage_collect_thread(c);
		down(&c->alloc_sem);
		jffs2_flush_wbuf_pad(c);
		up(&c->alloc_sem);
	}

	if (!(*flags & MS_RDONLY))
		jffs2_start_garbage_collect_thread(c);

	*flags |= MS_NOATIME;

	return 0;
}

void jffs2_write_super (struct super_block *sb)
{
	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
	sb->s_dirt = 0;

	if (sb->s_flags & MS_RDONLY)
		return;

	D1(printk(KERN_DEBUG "jffs2_write_super()\n"));
	jffs2_garbage_collect_trigger(c);
	jffs2_erase_pending_blocks(c, 0);
	jffs2_flush_wbuf_gc(c, 0);
}


/* jffs2_new_inode: allocate a new inode and inocache, add it to the hash,
   fill in the raw_inode while you're at it. */
struct inode *jffs2_new_inode (struct inode *dir_i, int mode, struct jffs2_raw_inode *ri)
{
	struct inode *inode;
	struct super_block *sb = dir_i->i_sb;
	struct jffs2_sb_info *c;
	struct jffs2_inode_info *f;
	int ret;

	D1(printk(KERN_DEBUG "jffs2_new_inode(): dir_i %ld, mode 0x%x\n", dir_i->i_ino, mode));

	c = JFFS2_SB_INFO(sb);

	inode = new_inode(sb);

	if (!inode)
		return ERR_PTR(-ENOMEM);

	f = JFFS2_INODE_INFO(inode);
	jffs2_init_inode_info(f);
	down(&f->sem);

	memset(ri, 0, sizeof(*ri));
	/* Set OS-specific defaults for new inodes */
	ri->uid = cpu_to_je16(current->fsuid);

	if (dir_i->i_mode & S_ISGID) {
		ri->gid = cpu_to_je16(dir_i->i_gid);
		if (S_ISDIR(mode))
			mode |= S_ISGID;
	} else {
		ri->gid = cpu_to_je16(current->fsgid);
	}

	/* POSIX ACLs have to be processed now, at least partly.
	   The umask is only applied if there's no default ACL */
	ret = jffs2_init_acl_pre(dir_i, inode, &mode);
	if (ret) {
	    make_bad_inode(inode);
	    iput(inode);
	    return ERR_PTR(ret);
	}
	ret = jffs2_do_new_inode (c, f, mode, ri);
	if (ret) {
		make_bad_inode(inode);
		iput(inode);
		return ERR_PTR(ret);
	}
	inode->i_nlink = 1;
	inode->i_ino = je32_to_cpu(ri->ino);
	inode->i_mode = jemode_to_cpu(ri->mode);
	inode->i_gid = je16_to_cpu(ri->gid);
	inode->i_uid = je16_to_cpu(ri->uid);
	inode->i_atime = inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
	ri->atime = ri->mtime = ri->ctime = cpu_to_je32(I_SEC(inode->i_mtime));

	inode->i_blocks = 0;
	inode->i_size = 0;

	insert_inode_hash(inode);

	return inode;
}


int jffs2_do_fill_super(struct super_block *sb, void *data, int silent)
{
	struct jffs2_sb_info *c;
	struct inode *root_i;
	int ret;
	size_t blocks;

	c = JFFS2_SB_INFO(sb);

#ifndef CONFIG_JFFS2_FS_WRITEBUFFER
	if (c->mtd->type == MTD_NANDFLASH) {
		printk(KERN_ERR "jffs2: Cannot operate on NAND flash unless jffs2 NAND support is compiled in.\n");
		return -EINVAL;
	}
	if (c->mtd->type == MTD_DATAFLASH) {
		printk(KERN_ERR "jffs2: Cannot operate on DataFlash unless jffs2 DataFlash support is compiled in.\n");
		return -EINVAL;
	}
#endif

	c->flash_size = c->mtd->size;
	c->sector_size = c->mtd->erasesize;
	blocks = c->flash_size / c->sector_size;

	/*
	 * Size alignment check
	 */
	if ((c->sector_size * blocks) != c->flash_size) {
		c->flash_size = c->sector_size * blocks;
		printk(KERN_INFO "jffs2: Flash size not aligned to erasesize, reducing to %dKiB\n",
			c->flash_size / 1024);
	}

	if (c->flash_size < 5*c->sector_size) {
		printk(KERN_ERR "jffs2: Too few erase blocks (%d)\n", c->flash_size / c->sector_size);
		return -EINVAL;
	}

	c->cleanmarker_size = sizeof(struct jffs2_unknown_node);

	/* NAND (or other bizarre) flash... do setup accordingly */
	ret = jffs2_flash_setup(c);
	if (ret)
		return ret;

	c->inocache_list = kcalloc(INOCACHE_HASHSIZE, sizeof(struct jffs2_inode_cache *), GFP_KERNEL);
	if (!c->inocache_list) {
		ret = -ENOMEM;
		goto out_wbuf;
	}

	jffs2_init_xattr_subsystem(c);

	if ((ret = jffs2_do_mount_fs(c)))
		goto out_inohash;

	ret = -EINVAL;

	D1(printk(KERN_DEBUG "jffs2_do_fill_super(): Getting root inode\n"));
	root_i = iget(sb, 1);
	if (is_bad_inode(root_i)) {
		D1(printk(KERN_WARNING "get root inode failed\n"));
		goto out_root_i;
	}

	D1(printk(KERN_DEBUG "jffs2_do_fill_super(): d_alloc_root()\n"));
	sb->s_root = d_alloc_root(root_i);
	if (!sb->s_root)
		goto out_root_i;

	sb->s_maxbytes = 0xFFFFFFFF;
	sb->s_blocksize = PAGE_CACHE_SIZE;
	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	sb->s_magic = JFFS2_SUPER_MAGIC;
	if (!(sb->s_flags & MS_RDONLY))
		jffs2_start_garbage_collect_thread(c);
	return 0;

 out_root_i:
	iput(root_i);
	jffs2_free_ino_caches(c);
	jffs2_free_raw_node_refs(c);
	if (jffs2_blocks_use_vmalloc(c))
		vfree(c->blocks);
	else
		kfree(c->blocks);
 out_inohash:
	jffs2_clear_xattr_subsystem(c);
	kfree(c->inocache_list);
 out_wbuf:
	jffs2_flash_cleanup(c);

	return ret;
}

void jffs2_gc_release_inode(struct jffs2_sb_info *c,
				   struct jffs2_inode_info *f)
{
	iput(OFNI_EDONI_2SFFJ(f));
}

struct jffs2_inode_info *jffs2_gc_fetch_inode(struct jffs2_sb_info *c,
						     int inum, int nlink)
{
	struct inode *inode;
	struct jffs2_inode_cache *ic;
	if (!nlink) {
		/* The inode has zero nlink but its nodes weren't yet marked
		   obsolete. This has to be because we're still waiting for
		   the final (close() and) iput() to happen.

		   There's a possibility that the final iput() could have
		   happened while we were contemplating. In order to ensure
		   that we don't cause a new read_inode() (which would fail)
		   for the inode in question, we use ilookup() in this case
		   instead of iget().

		   The nlink can't _become_ zero at this point because we're
		   holding the alloc_sem, and jffs2_do_unlink() would also
		   need that while decrementing nlink on any inode.
		*/
		inode = ilookup(OFNI_BS_2SFFJ(c), inum);
		if (!inode) {
			D1(printk(KERN_DEBUG "ilookup() failed for ino #%u; inode is probably deleted.\n",
				  inum));

			spin_lock(&c->inocache_lock);
			ic = jffs2_get_ino_cache(c, inum);
			if (!ic) {
				D1(printk(KERN_DEBUG "Inode cache for ino #%u is gone.\n", inum));
				spin_unlock(&c->inocache_lock);
				return NULL;
			}
			if (ic->state != INO_STATE_CHECKEDABSENT) {
				/* Wait for progress. Don't just loop */
				D1(printk(KERN_DEBUG "Waiting for ino #%u in state %d\n",
					  ic->ino, ic->state));
				sleep_on_spinunlock(&c->inocache_wq, &c->inocache_lock);
			} else {
				spin_unlock(&c->inocache_lock);
			}

			return NULL;
		}
	} else {
		/* Inode has links to it still; they're not going away because
		   jffs2_do_unlink() would need the alloc_sem and we have it.
		   Just iget() it, and if read_inode() is necessary that's OK.
		*/
		inode = iget(OFNI_BS_2SFFJ(c), inum);
		if (!inode)
			return ERR_PTR(-ENOMEM);
	}
	if (is_bad_inode(inode)) {
		printk(KERN_NOTICE "Eep. read_inode() failed for ino #%u. nlink %d\n",
		       inum, nlink);
		/* NB. This will happen again. We need to do something appropriate here. */
		iput(inode);
		return ERR_PTR(-EIO);
	}

	return JFFS2_INODE_INFO(inode);
}

unsigned char *jffs2_gc_fetch_page(struct jffs2_sb_info *c,
				   struct jffs2_inode_info *f,
				   unsigned long offset,
				   unsigned long *priv)
{
	struct inode *inode = OFNI_EDONI_2SFFJ(f);
	struct page *pg;

	pg = read_cache_page_async(inode->i_mapping, offset >> PAGE_CACHE_SHIFT,
			     (void *)jffs2_do_readpage_unlock, inode);
	if (IS_ERR(pg))
		return (void *)pg;

	*priv = (unsigned long)pg;
	return kmap(pg);
}

void jffs2_gc_release_page(struct jffs2_sb_info *c,
			   unsigned char *ptr,
			   unsigned long *priv)
{
	struct page *pg = (void *)*priv;

	kunmap(pg);
	page_cache_release(pg);
}

static int jffs2_flash_setup(struct jffs2_sb_info *c) {
	int ret = 0;

	if (jffs2_cleanmarker_oob(c)) {
		/* NAND flash... do setup accordingly */
		ret = jffs2_nand_flash_setup(c);
		if (ret)
			return ret;
	}

	/* and Dataflash */
	if (jffs2_dataflash(c)) {
		ret = jffs2_dataflash_setup(c);
		if (ret)
			return ret;
	}

	/* and Intel "Sibley" flash */
	if (jffs2_nor_wbuf_flash(c)) {
		ret = jffs2_nor_wbuf_flash_setup(c);
		if (ret)
			return ret;
	}

	/* and an UBI volume */
	if (jffs2_ubivol(c)) {
		ret = jffs2_ubivol_setup(c);
		if (ret)
			return ret;
	}

	return ret;
}

void jffs2_flash_cleanup(struct jffs2_sb_info *c) {

	if (jffs2_cleanmarker_oob(c)) {
		jffs2_nand_flash_cleanup(c);
	}

	/* and DataFlash */
	if (jffs2_dataflash(c)) {
		jffs2_dataflash_cleanup(c);
	}

	/* and Intel "Sibley" flash */
	if (jffs2_nor_wbuf_flash(c)) {
		jffs2_nor_wbuf_flash_cleanup(c);
	}

	/* and an UBI volume */
	if (jffs2_ubivol(c)) {
		jffs2_ubivol_cleanup(c);
	}
}