1 files changed, 44 insertions, 10 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 5777e6a9aab1..a4e0963bf457 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -36,6 +36,7 @@
 #include "check-integrity.h"
 #include "rcu-string.h"
 #include "math.h"
+#include "dev-replace.h"
 
 static int init_first_rw_device(struct btrfs_trans_handle *trans,
                                 struct btrfs_root *root,
@@ -505,7 +506,8 @@ error:
         return ERR_PTR(-ENOMEM);
 }
 
-void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
+void btrfs_close_extra_devices(struct btrfs_fs_info *fs_info,
+                               struct btrfs_fs_devices *fs_devices, int step)
 {
         struct btrfs_device *device, *next;
 
@@ -528,6 +530,21 @@ again:
                         continue;
                 }
 
+                if (device->devid == BTRFS_DEV_REPLACE_DEVID) {
+                        /*
+                         * In the first step, keep the device which has
+                         * the correct fsid and the devid that is used
+                         * for the dev_replace procedure.
+                         * In the second step, the dev_replace state is
+                         * read from the device tree and it is known
+                         * whether the procedure is really active or
+                         * not, which means whether this device is
+                         * used or whether it should be removed.
+                         */
+                        if (step == 0 || device->is_tgtdev_for_dev_replace) {
+                                continue;
+                        }
+                }
                 if (device->bdev) {
                         blkdev_put(device->bdev, device->mode);
                         device->bdev = NULL;
@@ -536,7 +553,8 @@ again:
                 if (device->writeable) {
                         list_del_init(&device->dev_alloc_list);
                         device->writeable = 0;
-                        fs_devices->rw_devices--;
+                        if (!device->is_tgtdev_for_dev_replace)
+                                fs_devices->rw_devices--;
                 }
                 list_del_init(&device->dev_list);
                 fs_devices->num_devices--;
@@ -594,7 +612,7 @@ static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
                 if (device->bdev)
                         fs_devices->open_devices--;
 
-                if (device->writeable) {
+                if (device->writeable && !device->is_tgtdev_for_dev_replace) {
                         list_del_init(&device->dev_alloc_list);
                         fs_devices->rw_devices--;
                 }
@@ -718,7 +736,7 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
                         fs_devices->rotating = 1;
 
                 fs_devices->open_devices++;
-                if (device->writeable) {
+                if (device->writeable && !device->is_tgtdev_for_dev_replace) {
                         fs_devices->rw_devices++;
                         list_add(&device->dev_alloc_list,
                                  &fs_devices->alloc_list);
@@ -1350,16 +1368,22 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
                 root->fs_info->avail_system_alloc_bits |
                 root->fs_info->avail_metadata_alloc_bits;
 
-        if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
-            root->fs_info->fs_devices->num_devices <= 4) {
+        num_devices = root->fs_info->fs_devices->num_devices;
+        btrfs_dev_replace_lock(&root->fs_info->dev_replace);
+        if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) {
+                WARN_ON(num_devices < 1);
+                num_devices--;
+        }
+        btrfs_dev_replace_unlock(&root->fs_info->dev_replace);
+
+        if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices <= 4) {
                 printk(KERN_ERR "btrfs: unable to go below four devices "
                        "on raid10\n");
                 ret = -EINVAL;
                 goto out;
         }
 
-        if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
-            root->fs_info->fs_devices->num_devices <= 2) {
+        if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && num_devices <= 2) {
                 printk(KERN_ERR "btrfs: unable to go below two "
                        "devices on raid1\n");
                 ret = -EINVAL;
@@ -2935,6 +2959,7 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
         u64 allowed;
         int mixed = 0;
         int ret;
+        u64 num_devices;
 
         if (btrfs_fs_closing(fs_info) ||
             atomic_read(&fs_info->balance_pause_req) ||
@@ -2963,10 +2988,17 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
                 }
         }
 
+        num_devices = fs_info->fs_devices->num_devices;
+        btrfs_dev_replace_lock(&fs_info->dev_replace);
+        if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
+                BUG_ON(num_devices < 1);
+                num_devices--;
+        }
+        btrfs_dev_replace_unlock(&fs_info->dev_replace);
         allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
-        if (fs_info->fs_devices->num_devices == 1)
+        if (num_devices == 1)
                 allowed |= BTRFS_BLOCK_GROUP_DUP;
-        else if (fs_info->fs_devices->num_devices < 4)
+        else if (num_devices < 4)
                 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
         else
                 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
@@ -3591,6 +3623,7 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
                 devices_info[ndevs].total_avail = total_avail;
                 devices_info[ndevs].dev = device;
                 ++ndevs;
+                WARN_ON(ndevs > fs_devices->rw_devices);
         }
 
         /*
@@ -4773,6 +4806,7 @@ static void fill_device_from_item(struct extent_buffer *leaf,
         device->io_align = btrfs_device_io_align(leaf, dev_item);
         device->io_width = btrfs_device_io_width(leaf, dev_item);
         device->sector_size = btrfs_device_sector_size(leaf, dev_item);
+        WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID);
         device->is_tgtdev_for_dev_replace = 0;
 
         ptr = (unsigned long)btrfs_device_uuid(dev_item);