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| author | kib <kib@FreeBSD.org> | 2016-11-11 20:08:45 +0000 |
|---|---|---|
| committer | kib <kib@FreeBSD.org> | 2016-11-11 20:08:45 +0000 |
| commit | 3c5740752bf0ecd5cb090f5abe2061d76b84334c (patch) | |
| tree | cd8e0422b5e4f4cc553eebd514f6e4f2a40591f8 | |
| parent | 25601094ecaec03800a479180646621adcf26315 (diff) | |
| download | FreeBSD-src-3c5740752bf0ecd5cb090f5abe2061d76b84334c.zip FreeBSD-src-3c5740752bf0ecd5cb090f5abe2061d76b84334c.tar.gz | |
MFC r308025:
Enable vn_io_fault() deadlock avoidance for msdosfs.
| -rw-r--r-- | sys/fs/msdosfs/msdosfs_vfsops.c | 2 | ||||
| -rw-r--r-- | sys/fs/msdosfs/msdosfs_vnops.c | 10 |
2 files changed, 9 insertions, 3 deletions
diff --git a/sys/fs/msdosfs/msdosfs_vfsops.c b/sys/fs/msdosfs/msdosfs_vfsops.c index 259f739..66a64cb 100644 --- a/sys/fs/msdosfs/msdosfs_vfsops.c +++ b/sys/fs/msdosfs/msdosfs_vfsops.c @@ -743,7 +743,7 @@ mountmsdosfs(struct vnode *devvp, struct mount *mp) mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum; MNT_ILOCK(mp); mp->mnt_flag |= MNT_LOCAL; - mp->mnt_kern_flag |= MNTK_USES_BCACHE; + mp->mnt_kern_flag |= MNTK_USES_BCACHE | MNTK_NO_IOPF; MNT_IUNLOCK(mp); if (pmp->pm_flags & MSDOSFS_LARGEFS) diff --git a/sys/fs/msdosfs/msdosfs_vnops.c b/sys/fs/msdosfs/msdosfs_vnops.c index 3294656..ef35cea 100644 --- a/sys/fs/msdosfs/msdosfs_vnops.c +++ b/sys/fs/msdosfs/msdosfs_vnops.c @@ -640,7 +640,7 @@ msdosfs_read(ap) diff = blsize - bp->b_resid; if (diff < n) n = diff; - error = uiomove(bp->b_data + on, (int) n, uio); + error = vn_io_fault_uiomove(bp->b_data + on, (int) n, uio); brelse(bp); } while (error == 0 && uio->uio_resid > 0 && n != 0); if (!isadir && (error == 0 || uio->uio_resid != orig_resid) && @@ -776,6 +776,12 @@ msdosfs_write(ap) * then no need to read data from disk. */ bp = getblk(thisvp, bn, pmp->pm_bpcluster, 0, 0, 0); + /* + * This call to vfs_bio_clrbuf() ensures that + * even if vn_io_fault_uiomove() below faults, + * garbage from the newly instantiated buffer + * is not exposed to the userspace via mmap(). + */ vfs_bio_clrbuf(bp); /* * Do the bmap now, since pcbmap needs buffers @@ -813,7 +819,7 @@ msdosfs_write(ap) /* * Copy the data from user space into the buf header. */ - error = uiomove(bp->b_data + croffset, n, uio); + error = vn_io_fault_uiomove(bp->b_data + croffset, n, uio); if (error) { brelse(bp); break; |
