fs/jffs2/wbuf.c

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

File Facts

System
Linux kernel
Corpus path
fs/jffs2/wbuf.c
Extension
.c
Size
37798 bytes
Lines
1351
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

struct jffs2_inodirty {
	uint32_t ino;
	struct jffs2_inodirty *next;
};

static struct jffs2_inodirty inodirty_nomem;

static int jffs2_wbuf_pending_for_ino(struct jffs2_sb_info *c, uint32_t ino)
{
	struct jffs2_inodirty *this = c->wbuf_inodes;

	/* If a malloc failed, consider _everything_ dirty */
	if (this == &inodirty_nomem)
		return 1;

	/* If ino == 0, _any_ non-GC writes mean 'yes' */
	if (this && !ino)
		return 1;

	/* Look to see if the inode in question is pending in the wbuf */
	while (this) {
		if (this->ino == ino)
			return 1;
		this = this->next;
	}
	return 0;
}

static void jffs2_clear_wbuf_ino_list(struct jffs2_sb_info *c)
{
	struct jffs2_inodirty *this;

	this = c->wbuf_inodes;

	if (this != &inodirty_nomem) {
		while (this) {
			struct jffs2_inodirty *next = this->next;
			kfree(this);
			this = next;
		}
	}
	c->wbuf_inodes = NULL;
}

static void jffs2_wbuf_dirties_inode(struct jffs2_sb_info *c, uint32_t ino)
{
	struct jffs2_inodirty *new;

	/* Schedule delayed write-buffer write-out */
	jffs2_dirty_trigger(c);

	if (jffs2_wbuf_pending_for_ino(c, ino))
		return;

	new = kmalloc_obj(*new);
	if (!new) {
		jffs2_dbg(1, "No memory to allocate inodirty. Fallback to all considered dirty\n");
		jffs2_clear_wbuf_ino_list(c);
		c->wbuf_inodes = &inodirty_nomem;
		return;
	}
	new->ino = ino;
	new->next = c->wbuf_inodes;
	c->wbuf_inodes = new;
	return;
}

static inline void jffs2_refile_wbuf_blocks(struct jffs2_sb_info *c)
{
	struct list_head *this, *next;
	static int n;

	if (list_empty(&c->erasable_pending_wbuf_list))
		return;

	list_for_each_safe(this, next, &c->erasable_pending_wbuf_list) {
		struct jffs2_eraseblock *jeb = list_entry(this, struct jffs2_eraseblock, list);

		jffs2_dbg(1, "Removing eraseblock at 0x%08x from erasable_pending_wbuf_list...\n",
			  jeb->offset);
		list_del(this);
		if ((jiffies + (n++)) & 127) {
			/* Most of the time, we just erase it immediately. Otherwise we
			   spend ages scanning it on mount, etc. */
			jffs2_dbg(1, "...and adding to erase_pending_list\n");
			list_add_tail(&jeb->list, &c->erase_pending_list);
			c->nr_erasing_blocks++;
			jffs2_garbage_collect_trigger(c);
		} else {
			/* Sometimes, however, we leave it elsewhere so it doesn't get

Annotation

Implementation Notes