Merge tag 'mvebu-fixes-3.17' of git://git.infradead.org/linux-mvebu into next/fixes...

[cascardo/linux.git] / fs / btrfs / volumes.c

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 6cb82f6..340a92d 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -508,6 +508,44 @@ static noinline int device_list_add(const char *path,
                ret = 1;
                device->fs_devices = fs_devices;
        } else if (!device->name || strcmp(device->name->str, path)) {
+               /*
+                * When FS is already mounted.
+                * 1. If you are here and if the device->name is NULL that
+                *    means this device was missing at time of FS mount.
+                * 2. If you are here and if the device->name is different
+                *    from 'path' that means either
+                *      a. The same device disappeared and reappeared with
+                *         different name. or
+                *      b. The missing-disk-which-was-replaced, has
+                *         reappeared now.
+                *
+                * We must allow 1 and 2a above. But 2b would be a spurious
+                * and unintentional.
+                *
+                * Further in case of 1 and 2a above, the disk at 'path'
+                * would have missed some transaction when it was away and
+                * in case of 2a the stale bdev has to be updated as well.
+                * 2b must not be allowed at all time.
+                */
+
+               /*
+                * As of now don't allow update to btrfs_fs_device through
+                * the btrfs dev scan cli, after FS has been mounted.
+                */
+               if (fs_devices->opened) {
+                       return -EBUSY;
+               } else {
+                       /*
+                        * That is if the FS is _not_ mounted and if you
+                        * are here, that means there is more than one
+                        * disk with same uuid and devid.We keep the one
+                        * with larger generation number or the last-in if
+                        * generation are equal.
+                        */
+                       if (found_transid < device->generation)
+                               return -EEXIST;
+               }
+
                name = rcu_string_strdup(path, GFP_NOFS);
                if (!name)
                        return -ENOMEM;
@@ -519,6 +557,15 @@ static noinline int device_list_add(const char *path,
                }
        }
 
+       /*
+        * Unmount does not free the btrfs_device struct but would zero
+        * generation along with most of the other members. So just update
+        * it back. We need it to pick the disk with largest generation
+        * (as above).
+        */
+       if (!fs_devices->opened)
+               device->generation = found_transid;
+
        if (found_transid > fs_devices->latest_trans) {
                fs_devices->latest_devid = devid;
                fs_devices->latest_trans = found_transid;
@@ -1436,7 +1483,7 @@ static int btrfs_add_device(struct btrfs_trans_handle *trans,
        btrfs_set_device_io_align(leaf, dev_item, device->io_align);
        btrfs_set_device_io_width(leaf, dev_item, device->io_width);
        btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
-       btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
+       btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
        btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
        btrfs_set_device_group(leaf, dev_item, 0);
        btrfs_set_device_seek_speed(leaf, dev_item, 0);
@@ -1671,7 +1718,7 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
        device->fs_devices->total_devices--;
 
        if (device->missing)
-               root->fs_info->fs_devices->missing_devices--;
+               device->fs_devices->missing_devices--;
 
        next_device = list_entry(root->fs_info->fs_devices->devices.next,
                                 struct btrfs_device, dev_list);
@@ -1801,8 +1848,12 @@ void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info,
        if (srcdev->bdev) {
                fs_info->fs_devices->open_devices--;
 
-               /* zero out the old super */
-               btrfs_scratch_superblock(srcdev);
+               /*
+                * zero out the old super if it is not writable
+                * (e.g. seed device)
+                */
+               if (srcdev->writeable)
+                       btrfs_scratch_superblock(srcdev);
        }
 
        call_rcu(&srcdev->rcu, free_device);
@@ -1941,6 +1992,9 @@ static int btrfs_prepare_sprout(struct btrfs_root *root)
        fs_devices->seeding = 0;
        fs_devices->num_devices = 0;
        fs_devices->open_devices = 0;
+       fs_devices->missing_devices = 0;
+       fs_devices->num_can_discard = 0;
+       fs_devices->rotating = 0;
        fs_devices->seed = seed_devices;
 
        generate_random_uuid(fs_devices->fsid);
@@ -5800,7 +5854,8 @@ struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
        else
                generate_random_uuid(dev->uuid);
 
-       btrfs_init_work(&dev->work, pending_bios_fn, NULL, NULL);
+       btrfs_init_work(&dev->work, btrfs_submit_helper,
+                       pending_bios_fn, NULL, NULL);
 
        return dev;
 }