fs/ext4/symlink.c

Source file repositories/reference/linux-study-clean/fs/ext4/symlink.c

File Facts

System
Linux kernel
Corpus path
fs/ext4/symlink.c
Extension
.c
Size
3251 bytes
Lines
137
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

if (!bh) {
			EXT4_ERROR_INODE(inode, "bad symlink.");
			return ERR_PTR(-EFSCORRUPTED);
		}
		caddr = bh->b_data;
		max_size = inode->i_sb->s_blocksize;
	}

	paddr = fscrypt_get_symlink(inode, caddr, max_size, done);
	brelse(bh);
	return paddr;
}

static int ext4_encrypted_symlink_getattr(struct mnt_idmap *idmap,
					  const struct path *path,
					  struct kstat *stat, u32 request_mask,
					  unsigned int query_flags)
{
	ext4_getattr(idmap, path, stat, request_mask, query_flags);

	return fscrypt_symlink_getattr(path, stat);
}

static void ext4_free_link(void *bh)
{
	brelse(bh);
}

static const char *ext4_get_link(struct dentry *dentry, struct inode *inode,
				 struct delayed_call *callback)
{
	struct buffer_head *bh;
	char *inline_link;

	/*
	 * Create a new inlined symlink is not supported, just provide a
	 * method to read the leftovers.
	 */
	if (ext4_has_inline_data(inode)) {
		if (!dentry)
			return ERR_PTR(-ECHILD);

		inline_link = ext4_read_inline_link(inode);
		if (!IS_ERR(inline_link))
			set_delayed_call(callback, kfree_link, inline_link);
		return inline_link;
	}

	if (!dentry) {
		bh = ext4_getblk(NULL, inode, 0, EXT4_GET_BLOCKS_CACHED_NOWAIT);
		if (IS_ERR_OR_NULL(bh))
			return ERR_PTR(-ECHILD);
		if (!ext4_buffer_uptodate(bh)) {
			brelse(bh);
			return ERR_PTR(-ECHILD);
		}
	} else {
		bh = ext4_bread(NULL, inode, 0, 0);
		if (IS_ERR(bh))
			return ERR_CAST(bh);
		if (!bh) {
			EXT4_ERROR_INODE(inode, "bad symlink.");
			return ERR_PTR(-EFSCORRUPTED);
		}
	}

	set_delayed_call(callback, ext4_free_link, bh);
	nd_terminate_link(bh->b_data, inode->i_size,
			  inode->i_sb->s_blocksize - 1);
	return bh->b_data;
}

const struct inode_operations ext4_encrypted_symlink_inode_operations = {
	.get_link	= ext4_encrypted_get_link,
	.setattr	= ext4_setattr,
	.getattr	= ext4_encrypted_symlink_getattr,
	.listxattr	= ext4_listxattr,
};

const struct inode_operations ext4_symlink_inode_operations = {
	.get_link	= ext4_get_link,
	.setattr	= ext4_setattr,
	.getattr	= ext4_getattr,
	.listxattr	= ext4_listxattr,
};

const struct inode_operations ext4_fast_symlink_inode_operations = {
	.get_link	= simple_get_link,
	.setattr	= ext4_setattr,
	.getattr	= ext4_getattr,

Annotation

Implementation Notes