Merge to Fedora kernel-2.6.17-1.2187_FC5 patched with stable patch-2.6.17.13-vs2...

[linux-2.6.git] / drivers / md / dm-exception-store.c

diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c
index cc07bbe..34a7593 100644 (file)
--- a/drivers/md/dm-exception-store.c
+++ b/drivers/md/dm-exception-store.c
@@ -91,7 +91,6 @@ struct pstore {
        struct dm_snapshot *snap;       /* up pointer to my snapshot */
        int version;
        int valid;
-       uint32_t chunk_size;
        uint32_t exceptions_per_area;
 
        /*
@@ -133,7 +132,7 @@ static int alloc_area(struct pstore *ps)
        int r = -ENOMEM;
        size_t len;
 
-       len = ps->chunk_size << SECTOR_SHIFT;
+       len = ps->snap->chunk_size << SECTOR_SHIFT;
 
        /*
         * Allocate the chunk_size block of memory that will hold
@@ -160,8 +159,8 @@ static int chunk_io(struct pstore *ps, uint32_t chunk, int rw)
        unsigned long bits;
 
        where.bdev = ps->snap->cow->bdev;
-       where.sector = ps->chunk_size * chunk;
-       where.count = ps->chunk_size;
+       where.sector = ps->snap->chunk_size * chunk;
+       where.count = ps->snap->chunk_size;
 
        return dm_io_sync_vm(1, &where, rw, ps->area, &bits);
 }
@@ -188,7 +187,7 @@ static int area_io(struct pstore *ps, uint32_t area, int rw)
 
 static int zero_area(struct pstore *ps, uint32_t area)
 {
-       memset(ps->area, 0, ps->chunk_size << SECTOR_SHIFT);
+       memset(ps->area, 0, ps->snap->chunk_size << SECTOR_SHIFT);
        return area_io(ps, area, WRITE);
 }
 
@@ -196,6 +195,7 @@ static int read_header(struct pstore *ps, int *new_snapshot)
 {
        int r;
        struct disk_header *dh;
+       chunk_t chunk_size;
 
        r = chunk_io(ps, 0, READ);
        if (r)
@@ -210,8 +210,29 @@ static int read_header(struct pstore *ps, int *new_snapshot)
                *new_snapshot = 0;
                ps->valid = le32_to_cpu(dh->valid);
                ps->version = le32_to_cpu(dh->version);
-               ps->chunk_size = le32_to_cpu(dh->chunk_size);
-
+               chunk_size = le32_to_cpu(dh->chunk_size);
+               if (ps->snap->chunk_size != chunk_size) {
+                       DMWARN("chunk size %llu in device metadata overrides "
+                              "table chunk size of %llu.",
+                              (unsigned long long)chunk_size,
+                              (unsigned long long)ps->snap->chunk_size);
+
+                       /* We had a bogus chunk_size. Fix stuff up. */
+                       dm_io_put(sectors_to_pages(ps->snap->chunk_size));
+                       free_area(ps);
+
+                       ps->snap->chunk_size = chunk_size;
+                       ps->snap->chunk_mask = chunk_size - 1;
+                       ps->snap->chunk_shift = ffs(chunk_size) - 1;
+
+                       r = alloc_area(ps);
+                       if (r)
+                               return r;
+
+                       r = dm_io_get(sectors_to_pages(chunk_size));
+                       if (r)
+                               return r;
+               }
        } else {
                DMWARN("Invalid/corrupt snapshot");
                r = -ENXIO;
@@ -224,13 +245,13 @@ static int write_header(struct pstore *ps)
 {
        struct disk_header *dh;
 
-       memset(ps->area, 0, ps->chunk_size << SECTOR_SHIFT);
+       memset(ps->area, 0, ps->snap->chunk_size << SECTOR_SHIFT);
 
        dh = (struct disk_header *) ps->area;
        dh->magic = cpu_to_le32(SNAP_MAGIC);
        dh->valid = cpu_to_le32(ps->valid);
        dh->version = cpu_to_le32(ps->version);
-       dh->chunk_size = cpu_to_le32(ps->chunk_size);
+       dh->chunk_size = cpu_to_le32(ps->snap->chunk_size);
 
        return chunk_io(ps, 0, WRITE);
 }
@@ -365,7 +386,7 @@ static void persistent_destroy(struct exception_store *store)
 {
        struct pstore *ps = get_info(store);
 
-       dm_io_put(sectors_to_pages(ps->chunk_size));
+       dm_io_put(sectors_to_pages(ps->snap->chunk_size));
        vfree(ps->callbacks);
        free_area(ps);
        kfree(ps);
@@ -383,6 +404,16 @@ static int persistent_read_metadata(struct exception_store *store)
        if (r)
                return r;
 
+       /*
+        * Now we know correct chunk_size, complete the initialisation.
+        */
+       ps->exceptions_per_area = (ps->snap->chunk_size << SECTOR_SHIFT) /
+                                 sizeof(struct disk_exception);
+       ps->callbacks = dm_vcalloc(ps->exceptions_per_area,
+                       sizeof(*ps->callbacks));
+       if (!ps->callbacks)
+               return -ENOMEM;
+
        /*
         * Do we need to setup a new snapshot ?
         */
@@ -533,9 +564,6 @@ int dm_create_persistent(struct exception_store *store, uint32_t chunk_size)
        ps->snap = store->snap;
        ps->valid = 1;
        ps->version = SNAPSHOT_DISK_VERSION;
-       ps->chunk_size = chunk_size;
-       ps->exceptions_per_area = (chunk_size << SECTOR_SHIFT) /
-           sizeof(struct disk_exception);
        ps->next_free = 2;      /* skipping the header and first area */
        ps->current_committed = 0;
 
@@ -543,18 +571,9 @@ int dm_create_persistent(struct exception_store *store, uint32_t chunk_size)
        if (r)
                goto bad;
 
-       /*
-        * Allocate space for all the callbacks.
-        */
        ps->callback_count = 0;
        atomic_set(&ps->pending_count, 0);
-       ps->callbacks = dm_vcalloc(ps->exceptions_per_area,
-                                  sizeof(*ps->callbacks));
-
-       if (!ps->callbacks) {
-               r = -ENOMEM;
-               goto bad;
-       }
+       ps->callbacks = NULL;
 
        store->destroy = persistent_destroy;
        store->read_metadata = persistent_read_metadata;