/*- * SPDX-License-Identifier: BSD-4-Clause * * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank. * Copyright (C) 1994, 1995, 1997 TooLs GmbH. * All rights reserved. * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below). * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by TooLs GmbH. * 4. The name of TooLs GmbH may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /*- * 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 */ #include /* $NetBSD: msdosfs_vfsops.c,v 1.10 2016/01/30 09:59:27 mlelstv Exp $ */ __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include "msdos/denode.h" #include #include #include #include "makefs.h" #include "msdos.h" struct msdosfsmount * m_msdosfs_mount(struct m_vnode *devvp) { struct msdosfsmount *pmp = NULL; struct m_buf *bp; union bootsector *bsp; struct byte_bpb33 *b33; struct byte_bpb50 *b50; struct byte_bpb710 *b710; uint8_t SecPerClust; int ronly = 0, error; unsigned secsize = 512; MSDOSFS_DPRINTF(("%s(bread 0)\n", __func__)); if ((error = bread((void *)devvp, 0, secsize, 0, &bp)) != 0) goto error_exit; bsp = (union bootsector *)bp->b_data; b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB; b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB; b710 = (struct byte_bpb710 *)bsp->bs710.bsBPB; if (bsp->bs50.bsBootSectSig0 != BOOTSIG0 || bsp->bs50.bsBootSectSig1 != BOOTSIG1) { MSDOSFS_DPRINTF(("bootsig0 %d bootsig1 %d\n", bsp->bs50.bsBootSectSig0, bsp->bs50.bsBootSectSig1)); error = EINVAL; goto error_exit; } pmp = ecalloc(1, sizeof(*pmp)); /* * Compute several useful quantities from the bpb in the * bootsector. Copy in the dos 5 variant of the bpb then fix up * the fields that are different between dos 5 and dos 3.3. */ SecPerClust = b50->bpbSecPerClust; pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec); pmp->pm_ResSectors = getushort(b50->bpbResSectors); pmp->pm_FATs = b50->bpbFATs; pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts); pmp->pm_Sectors = getushort(b50->bpbSectors); pmp->pm_FATsecs = getushort(b50->bpbFATsecs); pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack); pmp->pm_Heads = getushort(b50->bpbHeads); pmp->pm_Media = b50->bpbMedia; MSDOSFS_DPRINTF(("%s(BytesPerSec=%u, ResSectors=%u, FATs=%d, " "RootDirEnts=%u, Sectors=%u, FATsecs=%lu, SecPerTrack=%u, " "Heads=%u, Media=%u)\n", __func__, pmp->pm_BytesPerSec, pmp->pm_ResSectors, pmp->pm_FATs, pmp->pm_RootDirEnts, pmp->pm_Sectors, pmp->pm_FATsecs, pmp->pm_SecPerTrack, pmp->pm_Heads, pmp->pm_Media)); /* XXX - We should probably check more values here */ if (!pmp->pm_BytesPerSec || !SecPerClust || pmp->pm_SecPerTrack > 63) { MSDOSFS_DPRINTF(("bytespersec %d secperclust %d " "secpertrack %d\n", pmp->pm_BytesPerSec, SecPerClust, pmp->pm_SecPerTrack)); error = EINVAL; goto error_exit; } if (pmp->pm_Sectors == 0) { pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs); pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors); } else { pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs); pmp->pm_HugeSectors = pmp->pm_Sectors; } pmp->pm_flags = 0; if (pmp->pm_RootDirEnts == 0) { unsigned short vers = getushort(b710->bpbFSVers); /* * Some say that bsBootSectSig[23] must be zero, but * Windows does not require this and some digital cameras * do not set these to zero. Therefore, do not insist. */ if (pmp->pm_Sectors || pmp->pm_FATsecs || vers) { MSDOSFS_DPRINTF(("sectors %d fatsecs %lu vers %d\n", pmp->pm_Sectors, pmp->pm_FATsecs, vers)); error = EINVAL; goto error_exit; } pmp->pm_fatmask = FAT32_MASK; pmp->pm_fatmult = 4; pmp->pm_fatdiv = 1; pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs); /* mirrorring is enabled if the FATMIRROR bit is not set */ if ((getushort(b710->bpbExtFlags) & FATMIRROR) == 0) pmp->pm_flags |= MSDOSFS_FATMIRROR; else pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM; } else pmp->pm_flags |= MSDOSFS_FATMIRROR; /* Check that fs has nonzero FAT size */ if (pmp->pm_FATsecs == 0) { MSDOSFS_DPRINTF(("FATsecs is 0\n")); error = EINVAL; goto error_exit; } pmp->pm_fatblk = pmp->pm_ResSectors; if (FAT32(pmp)) { pmp->pm_rootdirblk = getulong(b710->bpbRootClust); pmp->pm_firstcluster = pmp->pm_fatblk + (pmp->pm_FATs * pmp->pm_FATsecs); pmp->pm_fsinfo = getushort(b710->bpbFSInfo); } else { pmp->pm_rootdirblk = pmp->pm_fatblk + (pmp->pm_FATs * pmp->pm_FATsecs); pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry) + pmp->pm_BytesPerSec - 1) / pmp->pm_BytesPerSec;/* in sectors */ pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize; } pmp->pm_maxcluster = ((pmp->pm_HugeSectors - pmp->pm_firstcluster) / SecPerClust) + 1; pmp->pm_fatsize = pmp->pm_FATsecs * pmp->pm_BytesPerSec; if (pmp->pm_fatmask == 0) { if (pmp->pm_maxcluster <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) { /* * This will usually be a floppy disk. This size makes * sure that one FAT entry will not be split across * multiple blocks. */ pmp->pm_fatmask = FAT12_MASK; pmp->pm_fatmult = 3; pmp->pm_fatdiv = 2; } else { pmp->pm_fatmask = FAT16_MASK; pmp->pm_fatmult = 2; pmp->pm_fatdiv = 1; } } if (FAT12(pmp)) pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec; else pmp->pm_fatblocksize = MAXBSIZE; pmp->pm_fatblocksec = pmp->pm_fatblocksize / pmp->pm_BytesPerSec; pmp->pm_bnshift = ffs(pmp->pm_BytesPerSec) - 1; /* * Compute mask and shift value for isolating cluster relative byte * offsets and cluster numbers from a file offset. */ pmp->pm_bpcluster = SecPerClust * pmp->pm_BytesPerSec; pmp->pm_crbomask = pmp->pm_bpcluster - 1; pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1; MSDOSFS_DPRINTF(("%s(fatmask=%lu, fatmult=%u, fatdiv=%u, " "fatblocksize=%lu, fatblocksec=%lu, bnshift=%lu, pbcluster=%lu, " "crbomask=%lu, cnshift=%lu)\n", __func__, (unsigned long)pmp->pm_fatmask, pmp->pm_fatmult, pmp->pm_fatdiv, pmp->pm_fatblocksize, pmp->pm_fatblocksec, pmp->pm_bnshift, pmp->pm_bpcluster, pmp->pm_crbomask, pmp->pm_cnshift)); /* * Check for valid cluster size * must be a power of 2 */ if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) { MSDOSFS_DPRINTF(("bpcluster %lu cnshift %lu\n", pmp->pm_bpcluster, pmp->pm_cnshift)); error = EINVAL; goto error_exit; } /* * Release the bootsector buffer. */ brelse(bp); bp = NULL; /* * Check FSInfo. */ if (pmp->pm_fsinfo) { struct fsinfo *fp; /* * XXX If the fsinfo block is stored on media with * 2KB or larger sectors, is the fsinfo structure * padded at the end or in the middle? */ if ((error = bread((void *)devvp, pmp->pm_fsinfo, pmp->pm_BytesPerSec, 0, &bp)) != 0) goto error_exit; fp = (struct fsinfo *)bp->b_data; if (!memcmp(fp->fsisig1, "RRaA", 4) && !memcmp(fp->fsisig2, "rrAa", 4) && !memcmp(fp->fsisig3, "\0\0\125\252", 4)) pmp->pm_nxtfree = getulong(fp->fsinxtfree); else pmp->pm_fsinfo = 0; brelse(bp); bp = NULL; } /* * Check and validate (or perhaps invalidate?) the fsinfo structure? * XXX */ if (pmp->pm_fsinfo) { if ((pmp->pm_nxtfree == 0xffffffffUL) || (pmp->pm_nxtfree > pmp->pm_maxcluster)) pmp->pm_fsinfo = 0; } /* * Allocate memory for the bitmap of allocated clusters, and then * fill it in. */ pmp->pm_inusemap = ecalloc(sizeof(*pmp->pm_inusemap), ((pmp->pm_maxcluster + N_INUSEBITS) / N_INUSEBITS)); /* * fillinusemap() needs pm_devvp. */ pmp->pm_dev = 0; pmp->pm_devvp = (void *)devvp; /* * Have the inuse map filled in. */ if ((error = fillinusemap(pmp)) != 0) { MSDOSFS_DPRINTF(("fillinusemap %d\n", error)); goto error_exit; } /* * Finish up. */ if (ronly) pmp->pm_flags |= MSDOSFSMNT_RONLY; else pmp->pm_fmod = 1; /* * If we ever do quotas for DOS filesystems this would be a place * to fill in the info in the msdosfsmount structure. You dolt, * quotas on dos filesystems make no sense because files have no * owners on dos filesystems. of course there is some empty space * in the directory entry where we could put uid's and gid's. */ return pmp; error_exit: if (bp) brelse(bp); if (pmp) { if (pmp->pm_inusemap) free(pmp->pm_inusemap); free(pmp); } errno = error; return NULL; } int msdosfs_root(struct msdosfsmount *pmp, struct m_vnode *vp) { struct denode *ndep; int error; *vp = *(struct m_vnode *)pmp->pm_devvp; if ((error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, 0, &ndep)) != 0) { errno = error; return -1; } vp->v_data = ndep; return 0; } /* * If we have an FSInfo block, update it. */ int msdosfs_fsiflush(struct msdosfsmount *pmp) { struct fsinfo *fp; struct m_buf *bp; int error; if (pmp->pm_fsinfo == 0 || (pmp->pm_flags & MSDOSFS_FSIMOD) == 0) { error = 0; goto out; } error = bread((void *)pmp->pm_devvp, pmp->pm_fsinfo, pmp->pm_BytesPerSec, NOCRED, &bp); if (error != 0) { brelse(bp); goto out; } fp = (struct fsinfo *)bp->b_data; putulong(fp->fsinfree, pmp->pm_freeclustercount); putulong(fp->fsinxtfree, pmp->pm_nxtfree); pmp->pm_flags &= ~MSDOSFS_FSIMOD; error = bwrite(bp); out: return (error); }