Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull second set of btrfs updates from Chris Mason:
 "The most important changes here are from Josef, fixing a btrfs
  regression in 3.14 that can cause corruptions in the extent allocation
  tree when snapshots are in use.

  Josef also fixed some deadlocks in send/recv and other assorted races
  when balance is running"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (23 commits)
  Btrfs: fix compile warnings on on avr32 platform
  btrfs: allow mounting btrfs subvolumes with different ro/rw options
  btrfs: export global block reserve size as space_info
  btrfs: fix crash in remount(thread_pool=) case
  Btrfs: abort the transaction when we don't find our extent ref
  Btrfs: fix EINVAL checks in btrfs_clone
  Btrfs: fix unlock in __start_delalloc_inodes()
  Btrfs: scrub raid56 stripes in the right way
  Btrfs: don't compress for a small write
  Btrfs: more efficient io tree navigation on wait_extent_bit
  Btrfs: send, build path string only once in send_hole
  btrfs: filter invalid arg for btrfs resize
  Btrfs: send, fix data corruption due to incorrect hole detection
  Btrfs: kmalloc() doesn't return an ERR_PTR
  Btrfs: fix snapshot vs nocow writting
  btrfs: Change the expanding write sequence to fix snapshot related bug.
  btrfs: make device scan less noisy
  btrfs: fix lockdep warning with reclaim lock inversion
  Btrfs: hold the commit_root_sem when getting the commit root during send
  Btrfs: remove transaction from send
  ...

1 files changed, 24 insertions, 11 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d241130a32fd..49d7fab73360 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -448,6 +448,14 @@ static void pending_bios_fn(struct btrfs_work *work)
 	run_scheduled_bios(device);
 }
 
+/*
+ * Add new device to list of registered devices
+ *
+ * Returns:
+ * 1   - first time device is seen
+ * 0   - device already known
+ * < 0 - error
+ */
 static noinline int device_list_add(const char *path,
 			   struct btrfs_super_block *disk_super,
 			   u64 devid, struct btrfs_fs_devices **fs_devices_ret)
@@ -455,6 +463,7 @@ static noinline int device_list_add(const char *path,
 	struct btrfs_device *device;
 	struct btrfs_fs_devices *fs_devices;
 	struct rcu_string *name;
+	int ret = 0;
 	u64 found_transid = btrfs_super_generation(disk_super);
 
 	fs_devices = find_fsid(disk_super->fsid);
@@ -495,6 +504,7 @@ static noinline int device_list_add(const char *path,
 		fs_devices->num_devices++;
 		mutex_unlock(&fs_devices->device_list_mutex);
 
+		ret = 1;
 		device->fs_devices = fs_devices;
 	} else if (!device->name || strcmp(device->name->str, path)) {
 		name = rcu_string_strdup(path, GFP_NOFS);
@@ -513,7 +523,8 @@ static noinline int device_list_add(const char *path,
 		fs_devices->latest_trans = found_transid;
 	}
 	*fs_devices_ret = fs_devices;
-	return 0;
+
+	return ret;
 }
 
 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
@@ -910,17 +921,19 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 	transid = btrfs_super_generation(disk_super);
 	total_devices = btrfs_super_num_devices(disk_super);
 
-	if (disk_super->label[0]) {
-		if (disk_super->label[BTRFS_LABEL_SIZE - 1])
-			disk_super->label[BTRFS_LABEL_SIZE - 1] = '\0';
-		printk(KERN_INFO "BTRFS: device label %s ", disk_super->label);
-	} else {
-		printk(KERN_INFO "BTRFS: device fsid %pU ", disk_super->fsid);
-	}
-
-	printk(KERN_CONT "devid %llu transid %llu %s\n", devid, transid, path);
-
 	ret = device_list_add(path, disk_super, devid, fs_devices_ret);
+	if (ret > 0) {
+		if (disk_super->label[0]) {
+			if (disk_super->label[BTRFS_LABEL_SIZE - 1])
+				disk_super->label[BTRFS_LABEL_SIZE - 1] = '\0';
+			printk(KERN_INFO "BTRFS: device label %s ", disk_super->label);
+		} else {
+			printk(KERN_INFO "BTRFS: device fsid %pU ", disk_super->fsid);
+		}
+
+		printk(KERN_CONT "devid %llu transid %llu %s\n", devid, transid, path);
+		ret = 0;
+	}
 	if (!ret && fs_devices_ret)
 		(*fs_devices_ret)->total_devices = total_devices;