NetBSD/sys/pcfs/denode.h

249 lines
9.5 KiB
C

/*
* Written by Paul Popelka (paulp@uts.amdahl.com)
*
* You can do anything you want with this software,
* just don't say you wrote it,
* and don't remove this notice.
*
* This software is provided "as is".
*
* The author supplies this software to be publicly
* redistributed on the understanding that the author
* is not responsible for the correct functioning of
* this software in any circumstances and is not liable
* for any damages caused by this software.
*
* October 1992
*
* $Id: denode.h,v 1.3 1993/08/02 23:15:12 mycroft Exp $
*/
/*
* This is the pc filesystem specific portion of the
* vnode structure.
* To describe a file uniquely the de_dirclust, de_diroffset,
* and de_de.deStartCluster fields are used. de_dirclust
* contains the cluster number of the directory cluster containing
* the entry for a file or directory. de_diroffset is the
* index into the cluster for the entry describing a file
* or directory. de_de.deStartCluster is the number of the
* first cluster of the file or directory. Now to describe the
* quirks of the pc filesystem.
* - Clusters 0 and 1 are reserved.
* - The first allocatable cluster is 2.
* - The root directory is of fixed size and all blocks that
* make it up are contiguous.
* - Cluster 0 refers to the root directory when it is found
* in the startcluster field of a directory entry that points
* to another directory.
* - Cluster 0 implies a 0 length file when found in the start
* cluster field of a directory entry that points to a file.
* - You can't use the cluster number 0 to derive
* the address of the root directory.
* - Multiple directory entries can point to a directory.
* The entry in the parent directory points to a child
* directory. Any directories in the child directory contain
* a ".." entry that points back to the child. The child
* directory itself contains a "." entry that points to
* itself.
* - The root directory does not contain a "." or ".." entry.
* - Directory entries for directories are never changed once
* they are created (except when removed). The size stays
* 0, and the last modification time is never changed. This
* is because so many directory entries can point to the physical
* clusters that make up a directory. It would lead to an update
* nightmare.
* - The length field in a directory entry pointing to a directory
* contains 0 (always). The only way to find the end of a directory
* is to follow the cluster chain until the "last cluster"
* marker is found.
* My extensions to make this house of cards work. These apply
* only to the in memory copy of the directory entry.
* - A reference count for each denode will be kept since dos doesn't
* keep such things.
*/
/* Internal pseudo-offset for (nonexistent) directory entry for the root dir
* in the root dir */
#define PCFSROOT_OFS 0x1fffffff
/*
* The fat cache structure.
* fc_fsrcn is the filesystem relative cluster number
* that corresponds to the file relative cluster number
* in this structure (fc_frcn).
*/
struct fatcache {
u_short fc_frcn; /* file relative cluster number */
u_short fc_fsrcn; /* filesystem relative cluster number */
};
/*
* The fat entry cache as it stands helps make extending
* files a "quick" operation by avoiding having to scan
* the fat to discover the last cluster of the file.
* The cache also helps sequential reads by remembering
* the last cluster read from the file. This also prevents
* us from having to rescan the fat to find the next cluster
* to read. This cache is probably pretty worthless if a
* file is opened by multiple processes.
*/
#define FC_SIZE 2 /* number of entries in the cache */
#define FC_LASTMAP 0 /* entry the last call to pcbmap() resolved to */
#define FC_LASTFC 1 /* entry for the last cluster in the file */
#define FCE_EMPTY 0xffff /* doesn't represent an actual cluster # */
/*
* Set a slot in the fat cache.
*/
#define fc_setcache(dep, slot, frcn, fsrcn) \
(dep)->de_fc[slot].fc_frcn = frcn; \
(dep)->de_fc[slot].fc_fsrcn = fsrcn;
/*
* This is the in memory variant of a dos directory
* entry. It is usually contained within a vnode.
*/
struct denode {
struct denode *de_chain[2]; /* hash chain ptrs */
struct vnode *de_vnode; /* addr of vnode we are part of */
struct vnode *de_devvp; /* vnode of blk dev we live on */
u_long de_flag; /* flag bits */
dev_t de_dev; /* device where direntry lives */
u_long de_dirclust; /* cluster of the directory file
* containing this entry */
u_long de_diroffset; /* ordinal of this entry in the
* directory */
long de_refcnt; /* reference count */
struct pcfsmount *de_pmp; /* addr of our mount struct */
struct lockf *de_lockf; /* byte level lock list */
long de_spare0; /* current lock holder */
long de_spare1; /* lock wanter */
struct direntry de_de; /* the actual directory entry */
struct fatcache de_fc[FC_SIZE]; /* fat cache */
};
/*
* Values for the de_flag field of the denode.
*/
#define DELOCKED 0x0001 /* directory entry is locked */
#define DEWANT 0x0002 /* someone wants this de */
#define DERENAME 0x0004 /* de is being renamed */
#define DEUPD 0x0008 /* file has been modified */
#define DESHLOCK 0x0010 /* file has shared lock */
#define DEEXLOCK 0x0020 /* file has exclusive lock */
#define DELWAIT 0x0040 /* someone waiting on file lock */
#define DEMOD 0x0080 /* denode wants to be written back
* to disk */
/*
* Shorthand macros used to reference fields in the direntry
* contained in the denode structure.
*/
#define de_Name de_de.deName
#define de_Extension de_de.deExtension
#define de_Attributes de_de.deAttributes
#define de_Reserved de_de.deReserved
#define de_Time de_de.deTime
#define de_Date de_de.deDate
#define de_StartCluster de_de.deStartCluster
#define de_FileSize de_de.deFileSize
#define de_forw de_chain[0]
#define de_back de_chain[1]
#if defined(KERNEL)
#define VTODE(vp) ((struct denode *)(vp)->v_data)
#define DETOV(de) ((de)->de_vnode)
#define DELOCK(de) delock(de)
#define DEUNLOCK(de) deunlock(de)
#define DEUPDAT(dep, t, waitfor) \
if (dep->de_flag & DEUPD) \
(void) deupdat(dep, t, waitfor);
#define DETIMES(dep, t) \
if (dep->de_flag & DEUPD) { \
(dep)->de_flag |= DEMOD; \
unix2dostime(t, (union dosdate *)&dep->de_Date, \
(union dostime *)&dep->de_Time); \
(dep)->de_flag &= ~DEUPD; \
}
/*
* This overlays the fid sturcture (see mount.h)
*/
struct defid {
u_short defid_len; /* length of structure */
u_short defid_pad; /* force long alignment */
u_long defid_dirclust; /* cluster this dir entry came from */
u_long defid_dirofs; /* index of entry within the cluster */
/* u_long defid_gen; /* generation number */
};
/*
* Prototypes for PCFS vnode operations
*/
int pcfs_lookup __P((struct vnode *vp, struct nameidata *ndp, struct proc *p));
int pcfs_create __P((struct nameidata *ndp, struct vattr *vap, struct proc *p));
int pcfs_mknod __P((struct nameidata *ndp, struct vattr *vap, struct ucred *cred,
struct proc *p));
int pcfs_open __P((struct vnode *vp, int mode, struct ucred *cred,
struct proc *p));
int pcfs_close __P((struct vnode *vp, int fflag, struct ucred *cred,
struct proc *p));
int pcfs_access __P((struct vnode *vp, int mode, struct ucred *cred,
struct proc *p));
int pcfs_getattr __P((struct vnode *vp, struct vattr *vap, struct ucred *cred,
struct proc *p));
int pcfs_setattr __P((struct vnode *vp, struct vattr *vap, struct ucred *cred,
struct proc *p));
int pcfs_read __P((struct vnode *vp, struct uio *uio, int ioflag,
struct ucred *cred));
int pcfs_write __P((struct vnode *vp, struct uio *uio, int ioflag,
struct ucred *cred));
int pcfs_ioctl __P((struct vnode *vp, int command, caddr_t data, int fflag,
struct ucred *cred, struct proc *p));
int pcfs_select __P((struct vnode *vp, int which, int fflags, struct ucred *cred,
struct proc *p));
int pcfs_mmap __P((struct vnode *vp, int fflags, struct ucred *cred,
struct proc *p));
int pcfs_fsync __P((struct vnode *vp, int fflags, struct ucred *cred,
int waitfor, struct proc *p));
int pcfs_seek __P((struct vnode *vp, off_t oldoff, off_t newoff,
struct ucred *cred));
int pcfs_remove __P((struct nameidata *ndp, struct proc *p));
int pcfs_link __P((struct vnode *vp, struct nameidata *ndp, struct proc *p));
int pcfs_rename __P((struct nameidata *fndp, struct nameidata *tdnp,
struct proc *p));
int pcfs_mkdir __P((struct nameidata *ndp, struct vattr *vap, struct proc *p));
int pcfs_rmdir __P((struct nameidata *ndp, struct proc *p));
int pcfs_symlink __P((struct nameidata *ndp, struct vattr *vap, char *target,
struct proc *p));
int pcfs_readdir __P((struct vnode *vp, struct uio *uio, struct ucred *cred,
int *eofflagp));
int pcfs_readlink __P((struct vnode *vp, struct uio *uio, struct ucred *cred));
int pcfs_abortop __P((struct nameidata *ndp));
int pcfs_inactive __P((struct vnode *vp, struct proc *p));
int pcfs_reclaim __P((struct vnode *vp));
int pcfs_lock __P((struct vnode *vp));
int pcfs_unlock __P((struct vnode *vp));
int pcfs_bmap __P((struct vnode *vp, daddr_t bn, struct vnode **vpp,
daddr_t *bnp));
int pcfs_strategy __P((struct buf *bp));
void pcfs_print __P((struct vnode *vp));
int pcfs_islocked __P((struct vnode *vp));
int pcfs_advlock __P((struct vnode *vp, caddr_t id, int op, struct flock *fl,
int flags));
/*
* Internal service routine prototypes.
*/
int deget __P((struct pcfsmount *pmp, u_long dirclust, u_long diroffset,
struct direntry *direntptr, struct denode **depp));
#endif /* defined(KERNEL) */