Split the confusing loop in md_bitmap_init_from_disk that iterates over
all chunks but also needs to read and map the pages into three separate
loops: one that iterates over the pages to read them, a second optional
one to iterate over the pages to mark them invalid if the bitmaps are
out of date, and a final one that actually iterates over the chunks.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/md/md-bitmap.c | 142 ++++++++++++++++++++---------------------
1 file changed, 70 insertions(+), 72 deletions(-)
diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index fa0f6ca7b61b0b..1f71683b417981 100644
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -1065,33 +1065,31 @@ void md_bitmap_unplug_async(struct bitmap *bitmap)
EXPORT_SYMBOL(md_bitmap_unplug_async);
static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
-/* * bitmap_init_from_disk -- called at bitmap_create time to initialize
- * the in-memory bitmap from the on-disk bitmap -- also, sets up the
- * memory mapping of the bitmap file
- * Special cases:
- * if there's no bitmap file, or if the bitmap file had been
- * previously kicked from the array, we mark all the bits as
- * 1's in order to cause a full resync.
+
+/*
+ * Initialize the in-memory bitmap from the on-disk bitmap and set up the memory
+ * mapping of the bitmap file.
+ *
+ * Special case: If there's no bitmap file, or if the bitmap file had been
+ * previously kicked from the array, we mark all the bits as 1's in order to
+ * cause a full resync.
*
* We ignore all bits for sectors that end earlier than 'start'.
- * This is used when reading an out-of-date bitmap...
+ * This is used when reading an out-of-date bitmap.
*/
static int md_bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
{
- unsigned long i, chunks, index, oldindex, bit, node_offset = 0;
- struct page *page = NULL;
- unsigned long bit_cnt = 0;
- struct file *file;
- unsigned long offset;
- int outofdate;
- int ret = -ENOSPC;
- void *paddr;
+ bool outofdate = test_bit(BITMAP_STALE, &bitmap->flags);
+ struct mddev *mddev = bitmap->mddev;
+ unsigned long chunks = bitmap->counts.chunks;
struct bitmap_storage *store = &bitmap->storage;
+ struct file *file = store->file;
+ unsigned long node_offset = 0;
+ unsigned long bit_cnt = 0;
+ unsigned long i;
+ int ret;
- chunks = bitmap->counts.chunks;
- file = store->file;
-
- if (!file && !bitmap->mddev->bitmap_info.offset) {
+ if (!file && !mddev->bitmap_info.offset) {
/* No permanent bitmap - fill with '1s'. */
store->filemap = NULL;
store->file_pages = 0;
@@ -1106,10 +1104,6 @@ static int md_bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
return 0;
}
- outofdate = test_bit(BITMAP_STALE, &bitmap->flags);
- if (outofdate)
- pr_warn("%s: bitmap file is out of date, doing full recovery\n", bmname(bitmap));
-
if (file && i_size_read(file->f_mapping->host) < store->bytes) {
pr_warn("%s: bitmap file too short %lu < %lu\n",
bmname(bitmap),
@@ -1118,65 +1112,70 @@ static int md_bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
goto err;
}
- oldindex = ~0L;
- offset = 0;
- if (!bitmap->mddev->bitmap_info.external)
- offset = sizeof(bitmap_super_t);
-
- if (mddev_is_clustered(bitmap->mddev))
+ if (mddev_is_clustered(mddev))
node_offset = bitmap->cluster_slot * (DIV_ROUND_UP(store->bytes, PAGE_SIZE));
- for (i = 0; i < chunks; i++) {
- int b;
- index = file_page_index(&bitmap->storage, i);
- bit = file_page_offset(&bitmap->storage, i);
- if (index != oldindex) { /* this is a new page, read it in */
- int count;
- /* unmap the old page, we're done with it */
- if (index == store->file_pages-1)
- count = store->bytes - index * PAGE_SIZE;
- else
- count = PAGE_SIZE;
- page = store->filemap[index];
- if (file)
- ret = read_file_page(file, index, bitmap,
- count, page);
- else
- ret = read_sb_page(
- bitmap->mddev,
- bitmap->mddev->bitmap_info.offset,
- page,
- index + node_offset, count);
-
- if (ret)
- goto err;
+ for (i = 0; i < store->file_pages; i++) {
+ struct page *page = store->filemap[i];
+ int count;
- oldindex = index;
+ /* unmap the old page, we're done with it */
+ if (i == store->file_pages - 1)
+ count = store->bytes - i * PAGE_SIZE;
+ else
+ count = PAGE_SIZE;
- if (outofdate) {
- /*
- * if bitmap is out of date, dirty the
- * whole page and write it out
- */
- paddr = kmap_atomic(page);
- memset(paddr + offset, 0xff,
- PAGE_SIZE - offset);
- kunmap_atomic(paddr);
- write_page(bitmap, page, 1);
+ if (file)
+ ret = read_file_page(file, i, bitmap, count, page);
+ else
+ ret = read_sb_page(mddev, mddev->bitmap_info.offset,
+ page, i + node_offset, count);
+ if (ret)
+ goto err;
+ }
+
+ if (outofdate) {
+ pr_warn("%s: bitmap file is out of date, doing full recovery\n",
+ bmname(bitmap));
+
+ for (i = 0; i < store->file_pages; i++) {
+ struct page *page = store->filemap[i];
+ unsigned long offset = 0;
+ void *paddr;
+
+ if (i == 0 && !mddev->bitmap_info.external)
+ offset = sizeof(bitmap_super_t);
+
+ /*
+ * If the bitmap is out of date, dirty the whole page
+ * and write it out
+ */
+ paddr = kmap_atomic(page);
+ memset(paddr + offset, 0xff, PAGE_SIZE - offset);
+ kunmap_atomic(paddr);
+ write_page(bitmap, page, 1);
+ if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags)) {
ret = -EIO;
- if (test_bit(BITMAP_WRITE_ERROR,
- &bitmap->flags))
- goto err;
+ goto err;
}
}
+ }
+
+ for (i = 0; i < chunks; i++) {
+ struct page *page = filemap_get_page(&bitmap->storage, i);
+ unsigned long bit = file_page_offset(&bitmap->storage, i);
+ void *paddr;
+ bool was_set;
+
paddr = kmap_atomic(page);
if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
- b = test_bit(bit, paddr);
+ was_set = test_bit(bit, paddr);
else
- b = test_bit_le(bit, paddr);
+ was_set = test_bit_le(bit, paddr);
kunmap_atomic(paddr);
- if (b) {
+
+ if (was_set) {
/* if the disk bit is set, set the memory bit */
int needed = ((sector_t)(i+1) << bitmap->counts.chunkshift
>= start);
@@ -1185,7 +1184,6 @@ static int md_bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
needed);
bit_cnt++;
}
- offset = 0;
}
pr_debug("%s: bitmap initialized from disk: read %lu pages, set %lu of %lu bits\n",
--
2.39.2
