[src/trunk]: src/sys/dev Fix dumping code (dk_dump):

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/f1e8f9b55089
branches:  trunk
changeset: 811296:f1e8f9b55089
user:      christos <christos%NetBSD.org@localhost>
date:      Wed Oct 21 21:43:46 2015 +0000

description:
Fix dumping code (dk_dump):
    - set DKF_TAKEDUMP on attach, otherwise we can never dump
    - add DKF_DUMP debugging
    - use __func__ instead of hard-coding names
    - only allow dumps on swap partitions

diffstat:

 sys/dev/dksubr.c |  69 +++++++++++++++++++++++++++++++++++++------------------
 1 files changed, 46 insertions(+), 23 deletions(-)

diffs (207 lines):

diff -r 44ef72753e7a -r f1e8f9b55089 sys/dev/dksubr.c
--- a/sys/dev/dksubr.c  Wed Oct 21 20:02:12 2015 +0000
+++ b/sys/dev/dksubr.c  Wed Oct 21 21:43:46 2015 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: dksubr.c,v 1.76 2015/08/28 17:41:49 mlelstv Exp $ */
+/* $NetBSD: dksubr.c,v 1.77 2015/10/21 21:43:46 christos Exp $ */
 
 /*-
  * Copyright (c) 1996, 1997, 1998, 1999, 2002, 2008 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: dksubr.c,v 1.76 2015/08/28 17:41:49 mlelstv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: dksubr.c,v 1.77 2015/10/21 21:43:46 christos Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -57,6 +57,7 @@
 #define DKDB_FOLLOW    0x1
 #define DKDB_INIT      0x2
 #define DKDB_VNODE     0x4
+#define DKDB_DUMP      0x8
 
 #define IFDEBUG(x,y)           if (dkdebug & (x)) y
 #define DPRINTF(x,y)           IFDEBUG(x, printf y)
@@ -67,6 +68,8 @@
 #define DPRINTF_FOLLOW(y)
 #endif
 
+#define DKF_READYFORDUMP       (DKF_INITED|DKF_TAKEDUMP)
+
 static int dk_subr_modcmd(modcmd_t, void *);
 
 #define DKLABELDEV(dev)        \
@@ -92,7 +95,7 @@
 dk_attach(struct dk_softc *dksc)
 {
        mutex_init(&dksc->sc_iolock, MUTEX_DEFAULT, IPL_VM);
-       dksc->sc_flags |= DKF_INITED;
+       dksc->sc_flags |= DKF_READYFORDUMP;
 #ifdef DIAGNOSTIC
        dksc->sc_flags |= DKF_WARNLABEL | DKF_LABELSANITY;
 #endif
@@ -108,7 +111,7 @@
        /* Unhook the entropy source. */
        rnd_detach_source(&dksc->sc_rnd_source);
 
-       dksc->sc_flags &= ~DKF_INITED;
+       dksc->sc_flags &= ~DKF_READYFORDUMP;
        mutex_destroy(&dksc->sc_iolock);
 }
 
@@ -123,7 +126,7 @@
        int     ret = 0;
        struct disk *dk = &dksc->sc_dkdev;
 
-       DPRINTF_FOLLOW(("dk_open(%s, %p, 0x%"PRIx64", 0x%x)\n",
+       DPRINTF_FOLLOW(("%s(%s, %p, 0x%"PRIx64", 0x%x)\n", __func__,
            dksc->sc_xname, dksc, dev, flags));
 
        mutex_enter(&dk->dk_openlock);
@@ -184,7 +187,7 @@
        int     pmask = 1 << part;
        struct disk *dk = &dksc->sc_dkdev;
 
-       DPRINTF_FOLLOW(("dk_close(%s, %p, 0x%"PRIx64", 0x%x)\n",
+       DPRINTF_FOLLOW(("%s(%s, %p, 0x%"PRIx64", 0x%x)\n", __func__,
            dksc->sc_xname, dksc, dev, flags));
 
        mutex_enter(&dk->dk_openlock);
@@ -275,11 +278,11 @@
 {
        int error;
 
-       DPRINTF_FOLLOW(("dk_strategy(%s, %p, %p)\n",
+       DPRINTF_FOLLOW(("%s(%s, %p, %p)\n", __func__,
            dksc->sc_xname, dksc, bp));
 
        if (!(dksc->sc_flags & DKF_INITED)) {
-               DPRINTF_FOLLOW(("dk_strategy: not inited\n"));
+               DPRINTF_FOLLOW(("%s: not inited\n", __func__));
                bp->b_error  = ENXIO;
                biodone(bp);
                return;
@@ -409,11 +412,11 @@
        struct buf tmp, *bp = &tmp;
        int error;
 
-       DPRINTF_FOLLOW(("dk_discard(%s, %p, 0x"PRIx64", %jd, %jd)\n",
+       DPRINTF_FOLLOW(("%s(%s, %p, 0x"PRIx64", %jd, %jd)\n", __func__,
            dksc->sc_xname, dksc, (intmax_t)pos, (intmax_t)len));
 
        if (!(dksc->sc_flags & DKF_INITED)) {
-               DPRINTF_FOLLOW(("dk_discard: not inited\n"));
+               DPRINTF_FOLLOW(("%s: not inited\n", __func__));
                return ENXIO;
        }
 
@@ -480,7 +483,7 @@
 #endif
        int     error;
 
-       DPRINTF_FOLLOW(("dk_ioctl(%s, %p, 0x%"PRIx64", 0x%lx)\n",
+       DPRINTF_FOLLOW(("%s(%s, %p, 0x%"PRIx64", 0x%lx)\n", __func__,
            dksc->sc_xname, dksc, dev, cmd));
 
        /* ensure that the pseudo disk is open for writes for these commands */
@@ -645,7 +648,6 @@
  *
  */
 
-#define DKF_READYFORDUMP       (DKF_INITED|DKF_TAKEDUMP)
 #define DKFF_READYFORDUMP(x)   (((x) & DKF_READYFORDUMP) == DKF_READYFORDUMP)
 static volatile int    dk_dumping = 0;
 
@@ -657,6 +659,7 @@
        const struct dkdriver *dkd = dksc->sc_dkdev.dk_driver;
        char *va = vav;
        struct disklabel *lp;
+       struct partition *p;
        int part, towrt, nsects, sectoff, maxblkcnt, nblk;
        int maxxfer, rv = 0;
 
@@ -664,16 +667,21 @@
         * ensure that we consider this device to be safe for dumping,
         * and that the device is configured.
         */
-       if (!DKFF_READYFORDUMP(dksc->sc_flags))
+       if (!DKFF_READYFORDUMP(dksc->sc_flags)) {
+               DPRINTF(DKF_DUMP, ("%s: bad dump flags 0x%x\n", __func__,
+                   dksc->sc_flags));
                return ENXIO;
+       }
 
        /* ensure that we are not already dumping */
        if (dk_dumping)
                return EFAULT;
        dk_dumping = 1;
 
-       if (dkd->d_dumpblocks == NULL)
+       if (dkd->d_dumpblocks == NULL) {
+               DPRINTF(DKF_DUMP, ("%s: no dumpblocks\n", __func__));
                return ENXIO;
+       }
 
        /* device specific max transfer size */
        maxxfer = MAXPHYS;
@@ -683,17 +691,28 @@
        /* Convert to disk sectors.  Request must be a multiple of size. */
        part = DISKPART(dev);
        lp = dksc->sc_dkdev.dk_label;
-       if ((size % lp->d_secsize) != 0)
-               return (EFAULT);
+       if ((size % lp->d_secsize) != 0) {
+               DPRINTF(DKF_DUMP, ("%s: odd size %zu\n", __func__, size));
+               return EFAULT;
+       }
        towrt = size / lp->d_secsize;
        blkno = dbtob(blkno) / lp->d_secsize;   /* blkno in secsize units */
 
-       nsects = lp->d_partitions[part].p_size;
-       sectoff = lp->d_partitions[part].p_offset;
+       p = &lp->d_partitions[part];
+       if (p->p_fstype != FS_SWAP) {
+               DPRINTF(DKF_DUMP, ("%s: bad fstype %d\n", __func__,
+                   p->p_fstype));
+               return ENXIO;
+       }
+       nsects = p->p_size;
+       sectoff = p->p_offset;
 
        /* Check transfer bounds against partition size. */
-       if ((blkno < 0) || ((blkno + towrt) > nsects))
-               return (EINVAL);
+       if ((blkno < 0) || ((blkno + towrt) > nsects)) {
+               DPRINTF(DKF_DUMP, ("%s: out of bounds blkno=%d, towrt=%d, "
+                   "nsects=%d\n", __func__, blkno, towrt, nsects));
+               return EINVAL;
+       }
 
        /* Offset block number to start of partition. */
        blkno += sectoff;
@@ -703,8 +722,12 @@
        while (towrt > 0) {
                nblk = min(maxblkcnt, towrt);
 
-               if ((rv = (*dkd->d_dumpblocks)(dksc->sc_dev, va, blkno, nblk)) != 0)
-                       return (rv);
+               if ((rv = (*dkd->d_dumpblocks)(dksc->sc_dev, va, blkno, nblk))
+                   != 0) {
+                       DPRINTF(DKF_DUMP, ("%s: dumpblocks %d\n", __func__,
+                           rv));
+                       return rv;
+               }
 
                towrt -= nblk;
                blkno += nblk;
@@ -832,7 +855,7 @@
        NDINIT(&nd, LOOKUP, FOLLOW, pb);
        if ((error = vn_open(&nd, FREAD | FWRITE, 0)) != 0) {
                DPRINTF((DKDB_FOLLOW|DKDB_INIT),
-                   ("dk_lookup: vn_open error = %d\n", error));
+                   ("%s: vn_open error = %d\n", __func__, error));
                return error;
        }