1 files changed, 51 insertions, 43 deletions

diff --git a/lib/sbitmap.c b/lib/sbitmap.c
index 2261136ae067..5b3e56d68dab 100644
--- a/lib/sbitmap.c
+++ b/lib/sbitmap.c
@@ -20,6 +20,47 @@
 #include <linux/sbitmap.h>
 #include <linux/seq_file.h>
 
+/*
+ * See if we have deferred clears that we can batch move
+ */
+static inline bool sbitmap_deferred_clear(struct sbitmap *sb, int index)
+{
+        unsigned long mask, val;
+        unsigned long __maybe_unused flags;
+        bool ret = false;
+
+        /* Silence bogus lockdep warning */
+#if defined(CONFIG_LOCKDEP)
+        local_irq_save(flags);
+#endif
+        spin_lock(&sb->map[index].swap_lock);
+
+        if (!sb->map[index].cleared)
+                goto out_unlock;
+
+        /*
+         * First get a stable cleared mask, setting the old mask to 0.
+         */
+        do {
+                mask = sb->map[index].cleared;
+        } while (cmpxchg(&sb->map[index].cleared, mask, 0) != mask);
+
+        /*
+         * Now clear the masked bits in our free word
+         */
+        do {
+                val = sb->map[index].word;
+        } while (cmpxchg(&sb->map[index].word, val, val & ~mask) != val);
+
+        ret = true;
+out_unlock:
+        spin_unlock(&sb->map[index].swap_lock);
+#if defined(CONFIG_LOCKDEP)
+        local_irq_restore(flags);
+#endif
+        return ret;
+}
+
 int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift,
                       gfp_t flags, int node)
 {
@@ -70,6 +111,9 @@ void sbitmap_resize(struct sbitmap *sb, unsigned int depth)
         unsigned int bits_per_word = 1U << sb->shift;
         unsigned int i;
 
+        for (i = 0; i < sb->map_nr; i++)
+                sbitmap_deferred_clear(sb, i);
+
         sb->depth = depth;
         sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word);
 
@@ -112,47 +156,6 @@ static int __sbitmap_get_word(unsigned long *word, unsigned long depth,
         return nr;
 }
 
-/*
- * See if we have deferred clears that we can batch move
- */
-static inline bool sbitmap_deferred_clear(struct sbitmap *sb, int index)
-{
-        unsigned long mask, val;
-        unsigned long __maybe_unused flags;
-        bool ret = false;
-
-        /* Silence bogus lockdep warning */
-#if defined(CONFIG_LOCKDEP)
-        local_irq_save(flags);
-#endif
-        spin_lock(&sb->map[index].swap_lock);
-
-        if (!sb->map[index].cleared)
-                goto out_unlock;
-
-        /*
-         * First get a stable cleared mask, setting the old mask to 0.
-         */
-        do {
-                mask = sb->map[index].cleared;
-        } while (cmpxchg(&sb->map[index].cleared, mask, 0) != mask);
-
-        /*
-         * Now clear the masked bits in our free word
-         */
-        do {
-                val = sb->map[index].word;
-        } while (cmpxchg(&sb->map[index].word, val, val & ~mask) != val);
-
-        ret = true;
-out_unlock:
-        spin_unlock(&sb->map[index].swap_lock);
-#if defined(CONFIG_LOCKDEP)
-        local_irq_restore(flags);
-#endif
-        return ret;
-}
-
 static int sbitmap_find_bit_in_index(struct sbitmap *sb, int index,
                                      unsigned int alloc_hint, bool round_robin)
 {
@@ -215,6 +218,7 @@ int sbitmap_get_shallow(struct sbitmap *sb, unsigned int alloc_hint,
         index = SB_NR_TO_INDEX(sb, alloc_hint);
 
         for (i = 0; i < sb->map_nr; i++) {
+again:
                 nr = __sbitmap_get_word(&sb->map[index].word,
                                         min(sb->map[index].depth, shallow_depth),
                                         SB_NR_TO_BIT(sb, alloc_hint), true);
@@ -223,6 +227,9 @@ int sbitmap_get_shallow(struct sbitmap *sb, unsigned int alloc_hint,
                         break;
                 }
 
+                if (sbitmap_deferred_clear(sb, index))
+                        goto again;
+
                 /* Jump to next index. */
                 index++;
                 alloc_hint = index << sb->shift;
@@ -242,7 +249,7 @@ bool sbitmap_any_bit_set(const struct sbitmap *sb)
         unsigned int i;
 
         for (i = 0; i < sb->map_nr; i++) {
-                if (sb->map[i].word)
+                if (sb->map[i].word & ~sb->map[i].cleared)
                         return true;
         }
         return false;
@@ -255,9 +262,10 @@ bool sbitmap_any_bit_clear(const struct sbitmap *sb)
 
         for (i = 0; i < sb->map_nr; i++) {
                 const struct sbitmap_word *word = &sb->map[i];
+                unsigned long mask = word->word & ~word->cleared;
                 unsigned long ret;
 
-                ret = find_first_zero_bit(&word->word, word->depth);
+                ret = find_first_zero_bit(&mask, word->depth);
                 if (ret < word->depth)
                         return true;
         }