libfdisk: fix sectorbuffer usage in dos driver

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/libfdisk/src/dos.c b/libfdisk/src/dos.c
index 9081e6ac187375e0bc5588b2bf5b5de502514200..d83da432e6ebcaece3410ca95b58babd8ae49666 100644 (file)
--- a/libfdisk/src/dos.c
+++ b/libfdisk/src/dos.c
@@ -133,6 +133,8 @@ static void partition_set_changed(
        if (!pe)
                return;
 
+       DBG(LABEL, dbgprint("DOS: setting %zu partition changed", i));
+
        pe->changed = changed ? 1 : 0;
        if (changed)
                fdisk_label_set_changed(cxt->label, 1);
@@ -203,6 +205,8 @@ static int read_pte(struct fdisk_context *cxt, int pno, sector_t offset)
        if (!buf)
                return -ENOMEM;
 
+       DBG(LABEL, dbgprint("DOS: reading pte %d sector buffer %p", pno, buf));
+
        pe->offset = offset;
        pe->sectorbuffer = buf;
        pe->private_sectorbuffer = 1;
@@ -241,6 +245,8 @@ static void dos_init(struct fdisk_context *cxt)
        assert(cxt->label);
        assert(fdisk_is_disklabel(cxt, DOS));
 
+       DBG(LABEL, dbgprint("DOS: initialize, first sector buffer %p", cxt->firstsector));
+
        cxt->label->nparts_max = 4;     /* default, unlimited number of logical */
 
        l->ext_index = 0;
@@ -256,6 +262,7 @@ static void dos_init(struct fdisk_context *cxt)
                pe->ex_entry = NULL;
                pe->offset = 0;
                pe->sectorbuffer = cxt->firstsector;
+               pe->private_sectorbuffer = 0;
                pe->changed = 0;
        }
 
@@ -305,9 +312,13 @@ static void dos_deinit(struct fdisk_label *lb)
        for (i = 0; i < ARRAY_SIZE(l->ptes); i++) {
                struct pte *pe = &l->ptes[i];
 
-               if (pe->private_sectorbuffer)
+               if (pe->private_sectorbuffer && pe->sectorbuffer) {
+                       DBG(LABEL, dbgprint("DOS: freeing pte %zu sector buffer %p",
+                                               i, pe->sectorbuffer));
                        free(pe->sectorbuffer);
+               }
                pe->sectorbuffer = NULL;
+               pe->private_sectorbuffer = 0;
        }
 
        memset(l->ptes, 0, sizeof(l->ptes));
@@ -328,6 +339,8 @@ static int dos_delete_partition(struct fdisk_context *cxt, size_t partnum)
        if (!pe)
                return -EINVAL;
 
+       DBG(LABEL, dbgprint("DOS: delete partiton %zu", partnum));
+
        l = self_label(cxt);
        p = pe->pt_entry;
        q = pe->ex_entry;
@@ -335,6 +348,7 @@ static int dos_delete_partition(struct fdisk_context *cxt, size_t partnum)
        /* Note that for the fifth partition (partnum == 4) we don't actually
           decrement partitions. */
        if (partnum < 4) {
+               DBG(LABEL, dbgprint("--> delete primary"));
                if (IS_EXTENDED(p->sys_ind) && partnum == l->ext_index) {
                        cxt->label->nparts_max = 4;
                        l->ptes[l->ext_index].ex_entry = NULL;
@@ -343,13 +357,13 @@ static int dos_delete_partition(struct fdisk_context *cxt, size_t partnum)
                partition_set_changed(cxt, partnum, 1);
                clear_partition(p);
        } else if (!q->sys_ind && partnum > 4) {
-               /* the last one in the chain - just delete */
+               DBG(LABEL, dbgprint("--> delete logical [last in the chain]"));
                --cxt->label->nparts_max;
                --partnum;
                clear_partition(l->ptes[partnum].ex_entry);
                partition_set_changed(cxt, partnum, 1);
        } else {
-               /* not the last one - further ones will be moved down */
+               DBG(LABEL, dbgprint("--> delete logical [non-last, move down]"));
                if (partnum > 4) {
                        /* delete this link in the chain */
                        p = l->ptes[partnum - 1].ex_entry;
@@ -371,10 +385,17 @@ static int dos_delete_partition(struct fdisk_context *cxt, size_t partnum)
 
                if (cxt->label->nparts_max > 5) {
                        cxt->label->nparts_max--;
+                       if (l->ptes[partnum].private_sectorbuffer) {
+                               DBG(LABEL, dbgprint("--> freeing pte %zu sector buffer %p",
+                                                       partnum, l->ptes[partnum].sectorbuffer));
+                               free(l->ptes[partnum].sectorbuffer);
+                       }
                        while (partnum < cxt->label->nparts_max) {
+                               DBG(LABEL, dbgprint("--> moving pte %zu <-- %zd", partnum, partnum + 1));
                                l->ptes[partnum] = l->ptes[partnum + 1];
                                partnum++;
                        }
+                       memset(&l->ptes[partnum], 0, sizeof(struct pte));
                } else
                        /* the only logical: clear only */
                        clear_partition(l->ptes[partnum].pt_entry);
@@ -401,6 +422,8 @@ static void read_extended(struct fdisk_context *cxt, int ext)
                return;
        }
 
+       DBG(LABEL, dbgprint("DOS: REading extended %d", ext));
+
        while (IS_EXTENDED (p->sys_ind)) {
                struct pte *pe = self_pte(cxt, cxt->label->nparts_max);
 
@@ -506,6 +529,8 @@ static int dos_create_disklabel(struct fdisk_context *cxt)
        assert(cxt->label);
        assert(fdisk_is_disklabel(cxt, DOS));
 
+       DBG(LABEL, dbgprint("DOS: creating new disklabel"));
+
        /* random disk signature */
        random_get_bytes(&id, sizeof(id));
 
@@ -536,6 +561,8 @@ static int dos_set_disklabel_id(struct fdisk_context *cxt)
        assert(cxt->label);
        assert(fdisk_is_disklabel(cxt, DOS));
 
+       DBG(LABEL, dbgprint("DOS: setting Id"));
+
        l = self_label(cxt);
        old = mbr_get_id(cxt->firstsector);
        rc = fdisk_ask_string(cxt,
@@ -601,6 +628,7 @@ static int dos_reset_alignment(struct fdisk_context *cxt)
 
        /* overwrite necessary stuff by DOS deprecated stuff */
        if (is_dos_compatible(cxt)) {
+               DBG(LABEL, dbgprint("DOS: reseting alignemnt for DOS-comaptiblem PT"));
                if (cxt->geom.sectors)
                        cxt->first_lba = cxt->geom.sectors;     /* usually 63 */
 
@@ -771,6 +799,8 @@ static int add_partition(struct fdisk_context *cxt, int n, struct fdisk_parttype
                first[cxt->label->nparts_max],
                last[cxt->label->nparts_max];
 
+       DBG(LABEL, dbgprint("DOS: adding partition %d", n));
+
        sys = t ? t->type : MBR_LINUX_DATA_PARTITION;
 
        if (p && p->sys_ind) {
@@ -951,6 +981,7 @@ static int add_partition(struct fdisk_context *cxt, int n, struct fdisk_parttype
                pe4->sectorbuffer = calloc(1, cxt->sector_size);
                if (!pe4->sectorbuffer)
                        return -ENOMEM;
+               DBG(LABEL, dbgprint("DOS: add partition, sector buffer %p", pe4->sectorbuffer));
                pe4->private_sectorbuffer = 1;
                pe4->pt_entry = mbr_get_partition(pe4->sectorbuffer, 0);
                pe4->ex_entry = pe4->pt_entry + 1;
@@ -976,6 +1007,7 @@ static int add_logical(struct fdisk_context *cxt)
                pe->sectorbuffer = calloc(1, cxt->sector_size);
                if (!pe->sectorbuffer)
                        return -ENOMEM;
+               DBG(LABEL, dbgprint("DOS: add logical, sector buffer %p", pe->sectorbuffer));
                pe->private_sectorbuffer = 1;
                pe->pt_entry = mbr_get_partition(pe->sectorbuffer, 0);
                pe->ex_entry = pe->pt_entry + 1;