segments: fix array sizes.

Heights range from 0 up, so the array must be sized
one larger than that maximum height.  So defined
SEG_NUM_HEIGHTS instead of SEG_MAX_HEIGHT, and make it one more.

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/segments.c b/segments.c
index 401e2ea75725233a4555b61050a6230eca734669..a941d690be30db89448e9400987664d0235c4b39 100644 (file)
--- a/segments.c
+++ b/segments.c
@@ -702,7 +702,7 @@ int lafs_segtrack_init(struct segtracker *st)
        st->size[1] = 1;
        st->size[2] = 5;
        st->size[3] = 9;
-       BUG_ON(9 > SEG_MAX_HEIGHT);
+       BUG_ON(SEG_NUM_HEIGHTS <= 9);
 
        st->unused.first = st->unused.last = 0xffff;
        st->cleanable.first = st->cleanable.last = 0xffff;
@@ -710,7 +710,7 @@ int lafs_segtrack_init(struct segtracker *st)
        st->clean.first = st->clean.last = 0xffff;
        st->unused.cnt = st->free.cnt = st->cleanable.cnt = 0;
 
-       for (h = 0; h < SEG_MAX_HEIGHT; h++)
+       for (h = 0; h < SEG_NUM_HEIGHTS; h++)
                st->head[h] = 0xFFFF;
 
        /* how many entries in each page */
@@ -888,14 +888,14 @@ static int statcmp(struct segstat *ss, u16 dev, u32 seg)
 }
 
 static struct segstat *segfind(struct segtracker *st, u16 dev,
-                              u32 segnum, u16 *where[SEG_MAX_HEIGHT])
+                              u32 segnum, u16 *where[SEG_NUM_HEIGHTS])
 {
        /* Find the segment entry for dev/segnum.
         * Return link info in where to allow insertion/deletion.
         */
        int level;
        u16 *head = st->head;
-       for (level = SEG_MAX_HEIGHT-1 ; level >= 0; level--) {
+       for (level = SEG_NUM_HEIGHTS-1 ; level >= 0; level--) {
                while (head[level] != 0xffff &&
                       statcmp(segfollow(st, head[level]), dev, segnum) < 0) {
                        head = segfollow(st, head[level])->skip;
@@ -911,7 +911,7 @@ static struct segstat *segfind(struct segtracker *st, u16 dev,
 
 static int segchoose_height(struct segtracker *st, u16 ssn)
 {
-       unsigned long rand[DIV_ROUND_UP(SEG_MAX_HEIGHT * 2 / 8 + 1,
+       unsigned long rand[DIV_ROUND_UP(SEG_NUM_HEIGHTS * 2 / 8 + 1,
                                        sizeof(unsigned long))];
        int max = st->size[ssn>>12];
        int h = 0;
@@ -928,7 +928,7 @@ static int segchoose_height(struct segtracker *st, u16 ssn)
 }
 
 static void seginsert(struct segtracker *st, u16 ssn,
-                     u16 *where[SEG_MAX_HEIGHT])
+                     u16 *where[SEG_NUM_HEIGHTS])
 {
        /* We looked for 'ss' but didn't find it.  'where' is the
         * result of looking.  Now insert 'ss'
@@ -947,7 +947,7 @@ static void segdelete(struct segtracker *st, struct segstat *ss)
        /* This segstat has just been removed from a list (free or cleanable).
         * Remove it from the skiplist as well
         */
-       u16 *where[SEG_MAX_HEIGHT];
+       u16 *where[SEG_NUM_HEIGHTS];
        struct segstat *ss2 = segfind(st, ss->dev, ss->segment, where);
        int h;
        int pos;
@@ -955,7 +955,7 @@ static void segdelete(struct segtracker *st, struct segstat *ss)
        BUG_ON(ss2 != ss);
 
        pos = *where[0];
-       for (h = 0; h < SEG_MAX_HEIGHT && *where[h] == pos ; h++)
+       for (h = 0; h < SEG_NUM_HEIGHTS && *where[h] == pos ; h++)
                *where[h] = ss->skip[h];
        ss->next = st->unused.first;
        st->unused.first = pos;
@@ -969,10 +969,10 @@ static void segdelete_all(struct segtracker *st, struct fs *fs)
        /* walk entire skip list.  Any entry with score of 0xFFFFFFFF
         * is deleted
         */
-       u16 *where[SEG_MAX_HEIGHT];
+       u16 *where[SEG_NUM_HEIGHTS];
        int h;
 
-       for (h = SEG_MAX_HEIGHT-1; h >= 0; h--)
+       for (h = SEG_NUM_HEIGHTS-1; h >= 0; h--)
                where[h] = &st->head[h];
 
        while (*where[0] != 0xFFFF) {
@@ -988,7 +988,7 @@ static void segdelete_all(struct segtracker *st, struct fs *fs)
                        putdref(ssm->youthblk, MKREF(intable));
                        ss_put(ssm, fs);
 
-                       for (h = 0; h < SEG_MAX_HEIGHT && *where[h] == pos; h++)
+                       for (h = 0; h < SEG_NUM_HEIGHTS && *where[h] == pos; h++)
                                *where[h] = ss->skip[h];
                        ss->next = st->unused.first;
                        st->unused.first = pos;
@@ -996,7 +996,7 @@ static void segdelete_all(struct segtracker *st, struct fs *fs)
                        lafs_check_seg_cnt(st);
                } else {
                        /* advance 'where' to here */
-                       for (h = 0; h < SEG_MAX_HEIGHT && *where[h] == pos; h++)
+                       for (h = 0; h < SEG_NUM_HEIGHTS && *where[h] == pos; h++)
                                where[h] = &ss->skip[h];
                }
        }
@@ -1115,7 +1115,7 @@ static int add_free(struct fs *fs, unsigned int dev, u32 seg, u16 *youthp)
 {
        /* This dev/seg is known to be free. add it to the list */
        struct segstat *ss;
-       u16 *where[SEG_MAX_HEIGHT];
+       u16 *where[SEG_NUM_HEIGHTS];
        int ssn;
 //printk("add_free %d %d\n", (int)dev, (int)seg);
        spin_lock(&fs->lock);
@@ -1168,7 +1168,7 @@ static int add_clean(struct fs *fs, unsigned int dev, u32 seg)
         * implies a reference count).
         */
        struct segstat *ss;
-       u16 *where[SEG_MAX_HEIGHT];
+       u16 *where[SEG_NUM_HEIGHTS];
        int ssn;
 
        dprintk("ADD CLEAN %d/%d %d #####################################\n",
@@ -1426,7 +1426,7 @@ static int add_cleanable(struct fs *fs, unsigned int dev, u32 seg,
        struct segstat *ss;
        int ssn;
        u32 segsize;
-       u16 *where[SEG_MAX_HEIGHT];
+       u16 *where[SEG_NUM_HEIGHTS];
 
        WARN_ON(lafs_check_seg_cnt(fs->segtrack));
        if (fs->scan.trace || lafs_trace)

diff --git a/state.h b/state.h
index b6f64c161d2b40c7258ca82180dbeccdd0b12055..1e789e063f2490e9d09076481cc65e5d00bbfcb4 100644 (file)
--- a/state.h
+++ b/state.h
@@ -151,7 +151,8 @@ struct fs {
        int     youth_block;    /* block number of next block to decay */
        int checkpoint_youth; // FIXME make sure this gets decayed
 
-#define        SEG_MAX_HEIGHT (9)
+/* 10 heights: 0 to 9 */
+#define        SEG_NUM_HEIGHTS (10)
        struct segtracker {
                void *page[4];
                int size[4]; /* entry size in page as "number of skip pointers" */
@@ -159,7 +160,7 @@ struct fs {
                        unsigned short first, last;
                        unsigned short cnt;
                } unused, free, cleanable, clean;
-               unsigned short head[SEG_MAX_HEIGHT]; /* head of skiplist */
+               unsigned short head[SEG_NUM_HEIGHTS]; /* head of skiplist */
                int total;
                int max_score;
                int sorted_size;