fs/9p/fid.h

Source file repositories/reference/linux-study-clean/fs/9p/fid.h

File Facts

System
Linux kernel
Corpus path
fs/9p/fid.h
Extension
.h
Size
1882 bytes
Lines
62
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

#ifndef FS_9P_FID_H
#define FS_9P_FID_H
#include <linux/list.h>
#include "v9fs.h"

struct p9_fid *v9fs_fid_find_inode(struct inode *inode, bool want_writeable,
	kuid_t uid, bool any);
struct p9_fid *v9fs_fid_lookup(struct dentry *dentry);
static inline struct p9_fid *v9fs_parent_fid(struct dentry *dentry)
{
	return v9fs_fid_lookup(dentry->d_parent);
}
void v9fs_fid_add(struct dentry *dentry, struct p9_fid **fid);
void v9fs_open_fid_add(struct inode *inode, struct p9_fid **fid);
static inline struct p9_fid *clone_fid(struct p9_fid *fid)
{
	return IS_ERR(fid) ? fid :  p9_client_walk(fid, 0, NULL, 1);
}
static inline struct p9_fid *v9fs_fid_clone(struct dentry *dentry)
{
	struct p9_fid *fid, *nfid;

	fid = v9fs_fid_lookup(dentry);
	if (!fid || IS_ERR(fid))
		return fid;

	nfid = clone_fid(fid);
	p9_fid_put(fid);
	return nfid;
}
/**
 * v9fs_fid_addmodes - add cache flags to fid mode (for client use only)
 * @fid: fid to augment
 * @s_flags: session info mount flags
 * @s_cache: session info cache flags
 * @f_flags: unix open flags
 *
 * make sure mode reflects flags of underlying mounts
 * also qid.version == 0 reflects a synthetic or legacy file system
 * NOTE: these are set after open so only reflect 9p client not
 * underlying file system on server.
 */
static inline void v9fs_fid_add_modes(struct p9_fid *fid, unsigned int s_flags,
	unsigned int s_cache, unsigned int f_flags)
{
	if ((!s_cache) ||
	   ((fid->qid.version == 0) && !(s_flags & V9FS_IGNORE_QV)) ||
	   (s_flags & V9FS_DIRECT_IO) || (f_flags & O_DIRECT)) {
		fid->mode |= P9L_DIRECT; /* no read or write cache */
	} else if ((!(s_cache & CACHE_WRITEBACK)) ||
				(f_flags & O_DSYNC) || (s_flags & V9FS_SYNC)) {
		fid->mode |= P9L_NOWRITECACHE;
	}
}
#endif

Annotation

Implementation Notes