133 lines
4.8 KiB
C
133 lines
4.8 KiB
C
/*
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* Written by Paul Popelka (paulp@uts.amdahl.com)
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*
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* You can do anything you want with this software, just don't say you wrote
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* it, and don't remove this notice.
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*
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* This software is provided "as is".
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*
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* The author supplies this software to be publicly redistributed on the
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* understanding that the author is not responsible for the correct
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* functioning of this software in any circumstances and is not liable for
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* any damages caused by this software.
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*
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* October 1992
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*
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* $Id: msdosfsmount.h,v 1.1 1993/08/13 11:35:41 cgd Exp $
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*/
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/*
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* Layout of the mount control block for a msdos file system.
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*/
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struct msdosfsmount {
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struct mount *pm_mountp;/* vfs mount struct for this fs */
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dev_t pm_dev; /* block special device mounted */
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struct vnode *pm_devvp; /* vnode for block device mntd */
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struct bpb50 pm_bpb; /* BIOS parameter blk for this fs */
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u_long pm_fatblk; /* block # of first FAT */
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u_long pm_rootdirblk; /* block # of root directory */
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u_long pm_rootdirsize; /* size in blocks (not clusters) */
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u_long pm_firstcluster; /* block number of first cluster */
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u_long pm_nmbrofclusters; /* # of clusters in filesystem */
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u_long pm_maxcluster; /* maximum cluster number */
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u_long pm_freeclustercount; /* number of free clusters */
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u_long pm_lookhere; /* start free cluster search here */
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u_long pm_bnshift; /* shift file offset right this amount to get a block number */
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u_long pm_brbomask; /* and a file offset with this mask to get block rel offset */
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u_long pm_cnshift; /* shift file offset right this amount to get a cluster number */
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u_long pm_crbomask; /* and a file offset with this mask to get cluster rel offset */
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u_long pm_bpcluster; /* bytes per cluster */
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u_long pm_depclust; /* directory entries per cluster */
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u_long pm_fmod; /* ~0 if fs is modified, this can rollover to 0 */
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u_long pm_fatblocksize; /* size of fat blocks in bytes */
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u_long pm_fatblocksec; /* size of fat blocks in sectors */
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u_long pm_fatsize; /* size of fat in bytes */
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u_char *pm_inusemap; /* ptr to bitmap of in-use clusters */
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char pm_ronly; /* read only if non-zero */
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char pm_waitonfat; /* wait for writes of the fat to complt, when 0 use bdwrite, else use bwrite */
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};
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/*
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* How to compute pm_cnshift and pm_crbomask.
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*
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* pm_crbomask = (pm_SectPerClust * pm_BytesPerSect) - 1
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* if (bytesperclust == * 0)
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* return EBADBLKSZ;
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* bit = 1;
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* for (i = 0; i < 32; i++) {
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* if (bit & bytesperclust) {
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* if (bit ^ bytesperclust)
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* return EBADBLKSZ;
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* pm_cnshift = * i;
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* break;
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* }
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* bit <<= 1;
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* }
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*/
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/*
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* Shorthand for fields in the bpb contained in the msdosfsmount structure.
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*/
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#define pm_BytesPerSec pm_bpb.bpbBytesPerSec
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#define pm_SectPerClust pm_bpb.bpbSecPerClust
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#define pm_ResSectors pm_bpb.bpbResSectors
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#define pm_FATs pm_bpb.bpbFATs
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#define pm_RootDirEnts pm_bpb.bpbRootDirEnts
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#define pm_Sectors pm_bpb.bpbSectors
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#define pm_Media pm_bpb.bpbMedia
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#define pm_FATsecs pm_bpb.bpbFATsecs
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#define pm_SecPerTrack pm_bpb.bpbSecPerTrack
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#define pm_Heads pm_bpb.bpbHeads
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#define pm_HiddenSects pm_bpb.bpbHiddenSecs
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#define pm_HugeSectors pm_bpb.bpbHugeSectors
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/*
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* Map a cluster number into a filesystem relative block number.
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*/
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#define cntobn(pmp, cn) \
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((((cn)-CLUST_FIRST) * (pmp)->pm_SectPerClust) + (pmp)->pm_firstcluster)
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/*
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* Map a filesystem relative block number back into a cluster number.
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*/
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#define bntocn(pmp, bn) \
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((((bn) - pmp->pm_firstcluster)/ (pmp)->pm_SectPerClust) + CLUST_FIRST)
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/*
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* Calculate block number for directory entry in root dir, offset dirofs
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*/
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#define roottobn(pmp, dirofs) \
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(((dirofs) / (pmp)->pm_depclust) * (pmp)->pm_SectPerClust \
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+ (pmp)->pm_rootdirblk)
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/*
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* Calculate block number for directory entry at cluster dirclu, offset
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* dirofs
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*/
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#define detobn(pmp, dirclu, dirofs) \
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((dirclu) == MSDOSFSROOT \
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? roottobn((pmp), (dirofs)) \
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: cntobn((pmp), (dirclu)))
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/*
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* Convert pointer to buffer -> pointer to direntry
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*/
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#define bptoep(pmp, bp, dirofs) \
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((struct direntry *)((bp)->b_un.b_addr) \
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+ (dirofs) % (pmp)->pm_depclust)
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/*
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* Prototypes for MSDOSFS virtual filesystem operations
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*/
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int msdosfs_mount __P((struct mount * mp, char *path, caddr_t data, struct nameidata * ndp, struct proc * p));
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int msdosfs_start __P((struct mount * mp, int flags, struct proc * p));
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int msdosfs_unmount __P((struct mount * mp, int mntflags, struct proc * p));
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int msdosfs_root __P((struct mount * mp, struct vnode ** vpp));
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int msdosfs_quotactl __P((struct mount * mp, int cmds, int uid /* should be uid_t */, caddr_t arg, struct proc * p));
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int msdosfs_statfs __P((struct mount * mp, struct statfs * sbp, struct proc * p));
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int msdosfs_sync __P((struct mount * mp, int waitfor));
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int msdosfs_fhtovp __P((struct mount * mp, struct fid * fhp, struct vnode ** vpp));
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int msdosfs_vptofh __P((struct vnode * vp, struct fid * fhp));
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int msdosfs_init __P(());
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