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Diffstat (limited to 'mm/swapfile.c')
-rw-r--r--mm/swapfile.c47
1 files changed, 41 insertions, 6 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 66e95eb73040..7e888de35c41 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -798,7 +798,7 @@ swp_entry_t get_swap_page_of_type(int type)
return (swp_entry_t) {0};
}
-static struct swap_info_struct *_swap_info_get(swp_entry_t entry)
+static struct swap_info_struct *__swap_info_get(swp_entry_t entry)
{
struct swap_info_struct *p;
unsigned long offset, type;
@@ -814,13 +814,8 @@ static struct swap_info_struct *_swap_info_get(swp_entry_t entry)
offset = swp_offset(entry);
if (offset >= p->max)
goto bad_offset;
- if (!p->swap_map[offset])
- goto bad_free;
return p;
-bad_free:
- pr_err("swap_info_get: %s%08lx\n", Unused_offset, entry.val);
- goto out;
bad_offset:
pr_err("swap_info_get: %s%08lx\n", Bad_offset, entry.val);
goto out;
@@ -833,6 +828,24 @@ out:
return NULL;
}
+static struct swap_info_struct *_swap_info_get(swp_entry_t entry)
+{
+ struct swap_info_struct *p;
+
+ p = __swap_info_get(entry);
+ if (!p)
+ goto out;
+ if (!p->swap_map[swp_offset(entry)])
+ goto bad_free;
+ return p;
+
+bad_free:
+ pr_err("swap_info_get: %s%08lx\n", Unused_offset, entry.val);
+ goto out;
+out:
+ return NULL;
+}
+
static struct swap_info_struct *swap_info_get(swp_entry_t entry)
{
struct swap_info_struct *p;
@@ -988,6 +1001,28 @@ int page_swapcount(struct page *page)
/*
* How many references to @entry are currently swapped out?
+ * This does not give an exact answer when swap count is continued,
+ * but does include the high COUNT_CONTINUED flag to allow for that.
+ */
+int __swp_swapcount(swp_entry_t entry)
+{
+ int count = 0;
+ pgoff_t offset;
+ struct swap_info_struct *si;
+ struct swap_cluster_info *ci;
+
+ si = __swap_info_get(entry);
+ if (si) {
+ offset = swp_offset(entry);
+ ci = lock_cluster_or_swap_info(si, offset);
+ count = swap_count(si->swap_map[offset]);
+ unlock_cluster_or_swap_info(si, ci);
+ }
+ return count;
+}
+
+/*
+ * How many references to @entry are currently swapped out?
* This considers COUNT_CONTINUED so it returns exact answer.
*/
int swp_swapcount(swp_entry_t entry)