NetBSD/sys/msdosfs/denode.h

215 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 1.2 1993/09/07 15:41:31 ws 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 MSDOSFSROOT_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 msdosfsmount *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 MSDOSFS vnode operations
*/
int msdosfs_lookup __P((struct vnode * vp, struct nameidata * ndp, struct proc * p));
int msdosfs_create __P((struct nameidata * ndp, struct vattr * vap, struct proc * p));
int msdosfs_mknod __P((struct nameidata * ndp, struct vattr * vap, struct ucred * cred, struct proc * p));
int msdosfs_open __P((struct vnode * vp, int mode, struct ucred * cred, struct proc * p));
int msdosfs_close __P((struct vnode * vp, int fflag, struct ucred * cred, struct proc * p));
int msdosfs_access __P((struct vnode * vp, int mode, struct ucred * cred, struct proc * p));
int msdosfs_getattr __P((struct vnode * vp, struct vattr * vap, struct ucred * cred, struct proc * p));
int msdosfs_setattr __P((struct vnode * vp, struct vattr * vap, struct ucred * cred, struct proc * p));
int msdosfs_read __P((struct vnode * vp, struct uio * uio, int ioflag, struct ucred * cred));
int msdosfs_write __P((struct vnode * vp, struct uio * uio, int ioflag, struct ucred * cred));
int msdosfs_ioctl __P((struct vnode * vp, int command, caddr_t data, int fflag, struct ucred * cred, struct proc * p));
int msdosfs_select __P((struct vnode * vp, int which, int fflags, struct ucred * cred, struct proc * p));
int msdosfs_mmap __P((struct vnode * vp, int fflags, struct ucred * cred, struct proc * p));
int msdosfs_fsync __P((struct vnode * vp, int fflags, struct ucred * cred, int waitfor, struct proc * p));
int msdosfs_seek __P((struct vnode * vp, off_t oldoff, off_t newoff, struct ucred * cred));
int msdosfs_remove __P((struct nameidata * ndp, struct proc * p));
int msdosfs_link __P((struct vnode * vp, struct nameidata * ndp, struct proc * p));
int msdosfs_rename __P((struct nameidata * fndp, struct nameidata * tdnp, struct proc * p));
int msdosfs_mkdir __P((struct nameidata * ndp, struct vattr * vap, struct proc * p));
int msdosfs_rmdir __P((struct nameidata * ndp, struct proc * p));
int msdosfs_symlink __P((struct nameidata * ndp, struct vattr * vap, char *target, struct proc * p));
int msdosfs_readdir __P((struct vnode * vp, struct uio * uio, struct ucred * cred, int *eofflagp, u_int * cookies, int ncookies));
int msdosfs_readlink __P((struct vnode * vp, struct uio * uio, struct ucred * cred));
int msdosfs_abortop __P((struct nameidata * ndp));
int msdosfs_inactive __P((struct vnode * vp, struct proc * p));
int msdosfs_reclaim __P((struct vnode * vp));
int msdosfs_lock __P((struct vnode * vp));
int msdosfs_unlock __P((struct vnode * vp));
int msdosfs_bmap __P((struct vnode * vp, daddr_t bn, struct vnode ** vpp, daddr_t * bnp));
int msdosfs_strategy __P((struct buf * bp));
int msdosfs_print __P((struct vnode * vp));
int msdosfs_islocked __P((struct vnode * vp));
int msdosfs_advlock __P((struct vnode * vp, caddr_t id, int op, struct flock * fl, int flags));
/*
* Internal service routine prototypes.
*/
int deget __P((struct msdosfsmount * pmp, u_long dirclust, u_long diroffset, struct direntry * direntptr, struct denode ** depp));
#endif /* defined(KERNEL) */