Btrfs: account for missing devices in RAID allocation profiles

[pandora-kernel.git] / fs / btrfs / volumes.c

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index dd318ff..177b731 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -413,12 +413,16 @@ static noinline int device_list_add(const char *path,
 
                device->fs_devices = fs_devices;
                fs_devices->num_devices++;
-       } else if (strcmp(device->name, path)) {
+       } else if (!device->name || strcmp(device->name, path)) {
                name = kstrdup(path, GFP_NOFS);
                if (!name)
                        return -ENOMEM;
                kfree(device->name);
                device->name = name;
+               if (device->missing) {
+                       fs_devices->missing_devices--;
+                       device->missing = 0;
+               }
        }
 
        if (found_transid > fs_devices->latest_trans) {
@@ -1238,6 +1242,9 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 
        device->fs_devices->num_devices--;
 
+       if (device->missing)
+               root->fs_info->fs_devices->missing_devices--;
+
        next_device = list_entry(root->fs_info->fs_devices->devices.next,
                                 struct btrfs_device, dev_list);
        if (device->bdev == root->fs_info->sb->s_bdev)
@@ -1901,7 +1908,6 @@ int btrfs_balance(struct btrfs_root *dev_root)
        u64 size_to_free;
        struct btrfs_path *path;
        struct btrfs_key key;
-       struct btrfs_chunk *chunk;
        struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
        struct btrfs_trans_handle *trans;
        struct btrfs_key found_key;
@@ -1965,9 +1971,6 @@ int btrfs_balance(struct btrfs_root *dev_root)
                if (found_key.objectid != key.objectid)
                        break;
 
-               chunk = btrfs_item_ptr(path->nodes[0],
-                                      path->slots[0],
-                                      struct btrfs_chunk);
                /* chunk zero is special */
                if (found_key.offset == 0)
                        break;
@@ -3034,8 +3037,7 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
                }
                bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
                dev = multi->stripes[dev_nr].dev;
-               BUG_ON(rw == WRITE && !dev->writeable);
-               if (dev && dev->bdev) {
+               if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
                        bio->bi_bdev = dev->bdev;
                        if (async_submit)
                                schedule_bio(root, dev, rw, bio);
@@ -3089,7 +3091,9 @@ static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
        device->devid = devid;
        device->work.func = pending_bios_fn;
        device->fs_devices = fs_devices;
+       device->missing = 1;
        fs_devices->num_devices++;
+       fs_devices->missing_devices++;
        spin_lock_init(&device->io_lock);
        INIT_LIST_HEAD(&device->dev_alloc_list);
        memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
@@ -3287,6 +3291,15 @@ static int read_one_dev(struct btrfs_root *root,
                        device = add_missing_dev(root, devid, dev_uuid);
                        if (!device)
                                return -ENOMEM;
+               } else if (!device->missing) {
+                       /*
+                        * this happens when a device that was properly setup
+                        * in the device info lists suddenly goes bad.
+                        * device->bdev is NULL, and so we have to set
+                        * device->missing to one here
+                        */
+                       root->fs_info->fs_devices->missing_devices++;
+                       device->missing = 1;
                }
        }