fs/qnx4/namei.c

Source file repositories/reference/linux-study-clean/fs/qnx4/namei.c

File Facts

System
Linux kernel
Corpus path
fs/qnx4/namei.c
Extension
.c
Size
2884 bytes
Lines
116
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) {
			block = qnx4_block_map(dir, blkofs);
			if (block)
				bh = sb_bread(dir->i_sb, block);
			if (!bh) {
				blkofs++;
				continue;
			}
		}
		*res_dir = (struct qnx4_inode_entry *) (bh->b_data + offset);
		if (qnx4_match(len, name, bh, &offset)) {
			*ino = block * QNX4_INODES_PER_BLOCK +
			    (offset / QNX4_DIR_ENTRY_SIZE) - 1;
			return bh;
		}
		if (offset < bh->b_size) {
			continue;
		}
		brelse(bh);
		bh = NULL;
		offset = 0;
		blkofs++;
	}
	brelse(bh);
	*res_dir = NULL;
	return NULL;
}

struct dentry * qnx4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
	int ino;
	struct qnx4_inode_entry *de;
	struct qnx4_link_info *lnk;
	struct buffer_head *bh;
	const char *name = dentry->d_name.name;
	int len = dentry->d_name.len;
	struct inode *foundinode = NULL;

	if (!(bh = qnx4_find_entry(len, dir, name, &de, &ino)))
		goto out;
	/* The entry is linked, let's get the real info */
	if ((de->di_status & QNX4_FILE_LINK) == QNX4_FILE_LINK) {
		lnk = (struct qnx4_link_info *) de;
		ino = (le32_to_cpu(lnk->dl_inode_blk) - 1) *
                    QNX4_INODES_PER_BLOCK +
		    lnk->dl_inode_ndx;
	}
	brelse(bh);

	foundinode = qnx4_iget(dir->i_sb, ino);
	if (IS_ERR(foundinode))
		QNX4DEBUG((KERN_ERR "qnx4: lookup->iget -> error %ld\n",
			   PTR_ERR(foundinode)));
out:
	return d_splice_alias(foundinode, dentry);
}

Annotation

Implementation Notes