Author: kib
Date: Fri Oct 28 11:35:06 2016
New Revision: 308025
URL: https://svnweb.freebsd.org/changeset/base/308025
Log:
Enable vn_io_fault() deadlock avoidance for msdosfs.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Modified:
head/sys/fs/msdosfs/msdosfs_vfsops.c
head/sys/fs/msdosfs/msdosfs_vnops.c
Modified: head/sys/fs/msdosfs/msdosfs_vfsops.c
==============================================================================
--- head/sys/fs/msdosfs/msdosfs_vfsops.c Fri Oct 28 11:34:32 2016
(r308024)
+++ head/sys/fs/msdosfs/msdosfs_vfsops.c Fri Oct 28 11:35:06 2016
(r308025)
@@ -742,7 +742,7 @@ mountmsdosfs(struct vnode *devvp, struct
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)
Modified: head/sys/fs/msdosfs/msdosfs_vnops.c
==============================================================================
--- head/sys/fs/msdosfs/msdosfs_vnops.c Fri Oct 28 11:34:32 2016
(r308024)
+++ head/sys/fs/msdosfs/msdosfs_vnops.c Fri Oct 28 11:35:06 2016
(r308025)
@@ -593,7 +593,7 @@ msdosfs_read(struct vop_read_args *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) &&
@@ -723,6 +723,12 @@ msdosfs_write(struct vop_write_args *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
@@ -760,7 +766,7 @@ msdosfs_write(struct vop_write_args *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;
_______________________________________________
svn-src-head@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-head
To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
