diff options
| author | bp <bp@FreeBSD.org> | 1999-12-28 15:27:39 +0000 |
|---|---|---|
| committer | bp <bp@FreeBSD.org> | 1999-12-28 15:27:39 +0000 |
| commit | 7b78445d14a1cb269afaf69f0d3184074ddc08f6 (patch) | |
| tree | 9f145b79fd165aba7bf1959568d9fa581995c7a2 /sys/msdosfs | |
| parent | 91e396f1556284c9b116cc39647735407acc41c5 (diff) | |
| download | FreeBSD-src-7b78445d14a1cb269afaf69f0d3184074ddc08f6.zip FreeBSD-src-7b78445d14a1cb269afaf69f0d3184074ddc08f6.tar.gz | |
It is possible that number of sectors specified in the BPB
will exceed FAT capacity. This will lead to kernel panic while other
systems just limit number of clusters.
PR: 4381, 15136
Reviewed by: phk
Diffstat (limited to 'sys/msdosfs')
| -rw-r--r-- | sys/msdosfs/msdosfs_vfsops.c | 19 | ||||
| -rw-r--r-- | sys/msdosfs/msdosfsmount.h | 1 |
2 files changed, 14 insertions, 6 deletions
diff --git a/sys/msdosfs/msdosfs_vfsops.c b/sys/msdosfs/msdosfs_vfsops.c index 4af4cf3..13272af 100644 --- a/sys/msdosfs/msdosfs_vfsops.c +++ b/sys/msdosfs/msdosfs_vfsops.c @@ -364,6 +364,7 @@ mountmsdosfs(devvp, mp, p, argp) struct byte_bpb50 *b50; struct byte_bpb710 *b710; u_int8_t SecPerClust; + u_long clusters; int ronly, error; /* @@ -595,14 +596,13 @@ mountmsdosfs(devvp, mp, p, argp) pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize; } - pmp->pm_nmbrofclusters = (pmp->pm_HugeSectors - pmp->pm_firstcluster) / - SecPerClust; - pmp->pm_maxcluster = pmp->pm_nmbrofclusters + 1; + pmp->pm_maxcluster = (pmp->pm_HugeSectors - pmp->pm_firstcluster) / + SecPerClust + 1; pmp->pm_fatsize = pmp->pm_FATsecs * pmp->pm_BytesPerSec; #ifndef __FreeBSD__ if (argp->flags & MSDOSFSMNT_GEMDOSFS) { - if ((pmp->pm_nmbrofclusters <= (0xff0 - 2)) + if ((pmp->pm_maxcluster <= (0xff0 - 2)) && ((dtype == DTYPE_FLOPPY) || ((dtype == DTYPE_VNODE) && ((pmp->pm_Heads == 1) || (pmp->pm_Heads == 2)))) ) { @@ -633,6 +633,15 @@ mountmsdosfs(devvp, mp, p, argp) pmp->pm_fatdiv = 1; } } + + clusters = (pmp->pm_fatsize / pmp->pm_fatmult) * pmp->pm_fatdiv; + if (pmp->pm_maxcluster >= clusters) { + printf("Warning: number of clusters (%ld) exceeds FAT " + "capacity (%ld)\n", pmp->pm_maxcluster + 1, clusters); + pmp->pm_maxcluster = clusters - 1; + } + + if (FAT12(pmp)) pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec; else @@ -829,7 +838,7 @@ msdosfs_statfs(mp, sbp, p) pmp = VFSTOMSDOSFS(mp); sbp->f_bsize = pmp->pm_bpcluster; sbp->f_iosize = pmp->pm_bpcluster; - sbp->f_blocks = pmp->pm_nmbrofclusters; + sbp->f_blocks = pmp->pm_maxcluster + 1; sbp->f_bfree = pmp->pm_freeclustercount; sbp->f_bavail = pmp->pm_freeclustercount; sbp->f_files = pmp->pm_RootDirEnts; /* XXX */ diff --git a/sys/msdosfs/msdosfsmount.h b/sys/msdosfs/msdosfsmount.h index 6bd6551..a8c2e5b 100644 --- a/sys/msdosfs/msdosfsmount.h +++ b/sys/msdosfs/msdosfsmount.h @@ -73,7 +73,6 @@ struct msdosfsmount { u_long pm_rootdirblk; /* block # (cluster # for FAT32) of root directory number */ 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_cnshift; /* shift file offset right this amount to get a cluster number */ |
