fs/jffs2/file.c

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

File Facts

System
Linux kernel
Corpus path
fs/jffs2/file.c
Extension
.c
Size
9697 bytes
Lines
337
Domain
Core OS
Bucket
VFS And Filesystem Core
Inferred role
Core OS: operation-table or driver-model contract
Status
pattern 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

const struct file_operations jffs2_file_operations =
{
	.llseek =	generic_file_llseek,
	.open =		generic_file_open,
 	.read_iter =	generic_file_read_iter,
 	.write_iter =	generic_file_write_iter,
	.unlocked_ioctl=jffs2_ioctl,
	.mmap_prepare =	generic_file_readonly_mmap_prepare,
	.fsync =	jffs2_fsync,
	.splice_read =	filemap_splice_read,
	.splice_write = iter_file_splice_write,
	.setlease =	generic_setlease,
};

/* jffs2_file_inode_operations */

const struct inode_operations jffs2_file_inode_operations =
{
	.get_inode_acl =	jffs2_get_acl,
	.set_acl =	jffs2_set_acl,
	.setattr =	jffs2_setattr,
	.listxattr =	jffs2_listxattr,
};

const struct address_space_operations jffs2_file_address_operations =
{
	.read_folio =	jffs2_read_folio,
	.write_begin =	jffs2_write_begin,
	.write_end =	jffs2_write_end,
};

static int jffs2_do_readpage_nolock(struct inode *inode, struct folio *folio)
{
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	unsigned char *kaddr;
	int ret;

	jffs2_dbg(2, "%s(): ino #%llu, page at offset 0x%lx\n",
		  __func__, inode->i_ino, folio->index << PAGE_SHIFT);

	BUG_ON(!folio_test_locked(folio));

	kaddr = kmap_local_folio(folio, 0);
	ret = jffs2_read_inode_range(c, f, kaddr, folio->index << PAGE_SHIFT,
				     PAGE_SIZE);
	kunmap_local(kaddr);

	if (!ret)
		folio_mark_uptodate(folio);

	flush_dcache_folio(folio);

	jffs2_dbg(2, "readpage finished\n");
	return ret;
}

int __jffs2_read_folio(struct file *file, struct folio *folio)
{
	int ret = jffs2_do_readpage_nolock(folio->mapping->host, folio);
	folio_unlock(folio);
	return ret;
}

static int jffs2_read_folio(struct file *file, struct folio *folio)
{
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(folio->mapping->host);
	int ret;

	mutex_lock(&f->sem);
	ret = __jffs2_read_folio(file, folio);
	mutex_unlock(&f->sem);
	return ret;
}

static int jffs2_write_begin(const struct kiocb *iocb,
			     struct address_space *mapping,
			     loff_t pos, unsigned len,
			     struct folio **foliop, void **fsdata)
{
	struct folio *folio;
	struct inode *inode = mapping->host;
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	pgoff_t index = pos >> PAGE_SHIFT;
	int ret = 0;

	jffs2_dbg(1, "%s()\n", __func__);

	if (pos > inode->i_size) {

Annotation

Implementation Notes