NetBSD/sys/msdosfs/msdosfsmount.h

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brought in fixed/renamed/matching MS-DOS FS code, from Jeff Polk <polk@bsdi.com>. His notes are as follows: ------------------------------------------------------------------------------ July 22, 1993 - Changed name of entire package from PCFS to MSDOSFS - Fixed bugs: root directory size in clusters instead of bytes growing directory didn't update in-core size link, symlink, mknod didn't free locked parent (deadlock) lookup returned real error on create and rename instead of EJUSTRETURN rename changed `.' entry in child instead of name entry in parent rename removed `.' entry in child instead of removing entry in parent when moving a directory from one dir to another createde() left new node locked when write of parent failed (deadlock) removede() decremented refcount even on error (rmdir's which failed due to write errors left in-core cache entries inconsistent) changed validation for filesystem to not check for the boot signature since some disks (e.g., mtools) aren't bootable directories are always show current time as modify time (needed for NFS export since DOS never updates dir mod times -- ctime is true create time). - Added support for cookies changes to the readdir() vnode interface (#ifdef __bsdi__) - Punted on the whole problem of inode generation numbers. This means that there's a chance of using a stale file handle to access a new file, but it doesn't appear to be the common case, and I don't see how to generate reasonable generation numbers without changing something on the disk (which is the way the SVR4 filesystem survival kit guys did it). I don't think it would be very safe to change the on-disk format. Jeff Polk (polk@BSDI.COM) ------------------------------------------------------------------------------
1993-08-13 15:35:13 +04:00
/*
* 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: msdosfsmount.h,v 1.1 1993/08/13 11:35:41 cgd Exp $
*/
/*
* Layout of the mount control block for a msdos file system.
*/
struct msdosfsmount {
struct mount *pm_mountp;/* vfs mount struct for this fs */
dev_t pm_dev; /* block special device mounted */
struct vnode *pm_devvp; /* vnode for block device mntd */
struct bpb50 pm_bpb; /* BIOS parameter blk for this fs */
u_long pm_fatblk; /* block # of first FAT */
u_long pm_rootdirblk; /* block # of root directory */
u_long pm_rootdirsize; /* size in blocks (not clusters) */
u_long pm_firstcluster; /* block number of first cluster */
u_long pm_nmbrofclusters; /* # of clusters in filesystem */
u_long pm_maxcluster; /* maximum cluster number */
u_long pm_freeclustercount; /* number of free clusters */
u_long pm_lookhere; /* start free cluster search here */
u_long pm_bnshift; /* shift file offset right this amount to get a block number */
u_long pm_brbomask; /* and a file offset with this mask to get block rel offset */
u_long pm_cnshift; /* shift file offset right this amount to get a cluster number */
u_long pm_crbomask; /* and a file offset with this mask to get cluster rel offset */
u_long pm_bpcluster; /* bytes per cluster */
u_long pm_depclust; /* directory entries per cluster */
u_long pm_fmod; /* ~0 if fs is modified, this can rollover to 0 */
u_long pm_fatblocksize; /* size of fat blocks in bytes */
u_long pm_fatblocksec; /* size of fat blocks in sectors */
u_long pm_fatsize; /* size of fat in bytes */
u_char *pm_inusemap; /* ptr to bitmap of in-use clusters */
char pm_ronly; /* read only if non-zero */
char pm_waitonfat; /* wait for writes of the fat to complt, when 0 use bdwrite, else use bwrite */
};
/*
* How to compute pm_cnshift and pm_crbomask.
*
* pm_crbomask = (pm_SectPerClust * pm_BytesPerSect) - 1
* if (bytesperclust == * 0)
* return EBADBLKSZ;
* bit = 1;
* for (i = 0; i < 32; i++) {
* if (bit & bytesperclust) {
* if (bit ^ bytesperclust)
* return EBADBLKSZ;
* pm_cnshift = * i;
* break;
* }
* bit <<= 1;
* }
*/
/*
* Shorthand for fields in the bpb contained in the msdosfsmount structure.
*/
#define pm_BytesPerSec pm_bpb.bpbBytesPerSec
#define pm_SectPerClust pm_bpb.bpbSecPerClust
#define pm_ResSectors pm_bpb.bpbResSectors
#define pm_FATs pm_bpb.bpbFATs
#define pm_RootDirEnts pm_bpb.bpbRootDirEnts
#define pm_Sectors pm_bpb.bpbSectors
#define pm_Media pm_bpb.bpbMedia
#define pm_FATsecs pm_bpb.bpbFATsecs
#define pm_SecPerTrack pm_bpb.bpbSecPerTrack
#define pm_Heads pm_bpb.bpbHeads
#define pm_HiddenSects pm_bpb.bpbHiddenSecs
#define pm_HugeSectors pm_bpb.bpbHugeSectors
/*
* Map a cluster number into a filesystem relative block number.
*/
#define cntobn(pmp, cn) \
((((cn)-CLUST_FIRST) * (pmp)->pm_SectPerClust) + (pmp)->pm_firstcluster)
/*
* Map a filesystem relative block number back into a cluster number.
*/
#define bntocn(pmp, bn) \
((((bn) - pmp->pm_firstcluster)/ (pmp)->pm_SectPerClust) + CLUST_FIRST)
/*
* Calculate block number for directory entry in root dir, offset dirofs
*/
#define roottobn(pmp, dirofs) \
(((dirofs) / (pmp)->pm_depclust) * (pmp)->pm_SectPerClust \
+ (pmp)->pm_rootdirblk)
/*
* Calculate block number for directory entry at cluster dirclu, offset
* dirofs
*/
#define detobn(pmp, dirclu, dirofs) \
((dirclu) == MSDOSFSROOT \
? roottobn((pmp), (dirofs)) \
: cntobn((pmp), (dirclu)))
/*
* Convert pointer to buffer -> pointer to direntry
*/
#define bptoep(pmp, bp, dirofs) \
((struct direntry *)((bp)->b_un.b_addr) \
+ (dirofs) % (pmp)->pm_depclust)
/*
* Prototypes for MSDOSFS virtual filesystem operations
*/
int msdosfs_mount __P((struct mount * mp, char *path, caddr_t data, struct nameidata * ndp, struct proc * p));
int msdosfs_start __P((struct mount * mp, int flags, struct proc * p));
int msdosfs_unmount __P((struct mount * mp, int mntflags, struct proc * p));
int msdosfs_root __P((struct mount * mp, struct vnode ** vpp));
int msdosfs_quotactl __P((struct mount * mp, int cmds, int uid /* should be uid_t */, caddr_t arg, struct proc * p));
int msdosfs_statfs __P((struct mount * mp, struct statfs * sbp, struct proc * p));
int msdosfs_sync __P((struct mount * mp, int waitfor));
int msdosfs_fhtovp __P((struct mount * mp, struct fid * fhp, struct vnode ** vpp));
int msdosfs_vptofh __P((struct vnode * vp, struct fid * fhp));
int msdosfs_init __P(());