Btrfs: disallow some operations on the device replace target device

This patch adds some code to disallow operations on the device that
is used as the target for the device replace operation.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

1 files changed, 9 insertions, 5 deletions

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 6cf23f4f7bb7..460e30bb1884 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -116,6 +116,9 @@ struct scrub_ctx {
         u32                     sectorsize;
         u32                     nodesize;
         u32                     leafsize;
+
+        int                     is_dev_replace;
+
         /*
          * statistics
          */
@@ -284,7 +287,7 @@ static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
 }
 
 static noinline_for_stack
-struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev)
+struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
 {
         struct scrub_ctx *sctx;
         int             i;
@@ -296,6 +299,7 @@ struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev)
         sctx = kzalloc(sizeof(*sctx), GFP_NOFS);
         if (!sctx)
                 goto nomem;
+        sctx->is_dev_replace = is_dev_replace;
         sctx->pages_per_bio = pages_per_bio;
         sctx->curr = -1;
         sctx->dev_root = dev->dev_root;
@@ -2293,7 +2297,7 @@ static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
 
 int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
                     u64 end, struct btrfs_scrub_progress *progress,
-                    int readonly)
+                    int readonly, int is_dev_replace)
 {
         struct scrub_ctx *sctx;
         int ret;
@@ -2356,14 +2360,14 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
 
         mutex_lock(&fs_info->fs_devices->device_list_mutex);
         dev = btrfs_find_device(fs_info, devid, NULL, NULL);
-        if (!dev || dev->missing) {
+        if (!dev || (dev->missing && !is_dev_replace)) {
                 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
                 scrub_workers_put(fs_info);
                 return -ENODEV;
         }
         mutex_lock(&fs_info->scrub_lock);
 
-        if (!dev->in_fs_metadata) {
+        if (!dev->in_fs_metadata || dev->is_tgtdev_for_dev_replace) {
                 mutex_unlock(&fs_info->scrub_lock);
                 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
                 scrub_workers_put(fs_info);
@@ -2376,7 +2380,7 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
                 scrub_workers_put(fs_info);
                 return -EINPROGRESS;
         }
-        sctx = scrub_setup_ctx(dev);
+        sctx = scrub_setup_ctx(dev, is_dev_replace);
         if (IS_ERR(sctx)) {
                 mutex_unlock(&fs_info->scrub_lock);
                 mutex_unlock(&fs_info->fs_devices->device_list_mutex);