[PATCH] btrfs: cleanup assigning next active device with a check

[PATCH] btrfs: cleanup assigning next active device with a check

[Anand Jain]

Creates helper fucntion as needed by the device delete
and replace operations. Also now it checks if the next
device being assigned is an active device.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 fs/btrfs/dev-replace.c |  8 +++-----
 fs/btrfs/volumes.c     | 51 +++++++++++++++++++++++++++++++++-----------------
 fs/btrfs/volumes.h     |  2 ++
 3 files changed, 39 insertions(+), 22 deletions(-)

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 8a0c77eb1291..be0958de9f2d 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -569,11 +569,9 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
 	ASSERT(list_empty(&src_device->resized_list));
 	tgt_device->commit_total_bytes = src_device->commit_total_bytes;
 	tgt_device->commit_bytes_used = src_device->bytes_used;
-	if (fs_info->sb->s_bdev &&
-		(fs_info->sb->s_bdev == src_device->bdev))
-		fs_info->sb->s_bdev = tgt_device->bdev;
-	if (fs_info->fs_devices->latest_bdev == src_device->bdev)
-		fs_info->fs_devices->latest_bdev = tgt_device->bdev;
+
+	btrfs_assign_next_active_device(fs_info, src_device, tgt_device);
+
 	list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list);
 	fs_info->fs_devices->rw_devices++;
 
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 81d37438919b..4ff716d9b16c 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1684,10 +1684,40 @@ out:
 	return ret;
 }
 
+struct btrfs_device *btrfs_find_next_active_device(struct btrfs_fs_devices *fs_devs,
+					struct btrfs_device *device)
+{
+	struct btrfs_device *next_device;
+
+	list_for_each_entry(next_device, &fs_devs->devices, dev_list) {
+		if (next_device != device &&
+			!next_device->missing && next_device->bdev)
+			return next_device;
+	}
+	return NULL;
+}
+
+void btrfs_assign_next_active_device(struct btrfs_fs_info *fs_info,
+		struct btrfs_device *device, struct btrfs_device *this_dev)
+{
+	struct btrfs_device *next_device;
+
+	if (this_dev)
+		next_device = this_dev;
+	else
+		next_device = btrfs_find_next_active_device(fs_info->fs_devices,
+								device);
+	if (fs_info->sb->s_bdev &&
+			(fs_info->sb->s_bdev == device->bdev))
+		fs_info->sb->s_bdev = next_device->bdev;
+
+	if (fs_info->fs_devices->latest_bdev == device->bdev)
+		fs_info->fs_devices->latest_bdev = next_device->bdev;
+}
+
 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 {
 	struct btrfs_device *device;
-	struct btrfs_device *next_device;
 	struct block_device *bdev;
 	struct buffer_head *bh = NULL;
 	struct btrfs_super_block *disk_super;
@@ -1838,13 +1868,7 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 	if (device->missing)
 		device->fs_devices->missing_devices--;
 
-	next_device = list_entry(root->fs_info->fs_devices->devices.next,
-				 struct btrfs_device, dev_list);
-	if (root->fs_info->sb->s_bdev &&
-		(root->fs_info->sb->s_bdev == device->bdev))
-		root->fs_info->sb->s_bdev = next_device->bdev;
-	if (device->bdev == root->fs_info->fs_devices->latest_bdev)
-		root->fs_info->fs_devices->latest_bdev = next_device->bdev;
+	btrfs_assign_next_active_device(root->fs_info, device, NULL);
 
 	if (device->bdev) {
 		device->fs_devices->open_devices--;
@@ -2014,8 +2038,6 @@ void btrfs_rm_dev_replace_free_srcdev(struct btrfs_fs_info *fs_info,
 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 				      struct btrfs_device *tgtdev)
 {
-	struct btrfs_device *next_device;
-
 	mutex_lock(&uuid_mutex);
 	WARN_ON(!tgtdev);
 	mutex_lock(&fs_info->fs_devices->device_list_mutex);
@@ -2027,13 +2049,8 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 
 	fs_info->fs_devices->num_devices--;
 
-	next_device = list_entry(fs_info->fs_devices->devices.next,
-				 struct btrfs_device, dev_list);
-	if (fs_info->sb->s_bdev &&
-		(tgtdev->bdev == fs_info->sb->s_bdev))
-		fs_info->sb->s_bdev = next_device->bdev;
-	if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
-		fs_info->fs_devices->latest_bdev = next_device->bdev;
+	btrfs_assign_next_active_device(fs_info, tgtdev, NULL);
+
 	list_del_rcu(&tgtdev->dev_list);
 
 	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 1939ebde63df..93e0a2560366 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -445,6 +445,8 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 			  struct btrfs_fs_devices **fs_devices_ret);
 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
 void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices, int step);
+void btrfs_assign_next_active_device(struct btrfs_fs_info *fs_info,
+		struct btrfs_device *device, struct btrfs_device *this_dev);
 int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
 					 char *device_path,
 					 struct btrfs_device **device);
-- 
2.7.0

Re: [PATCH] btrfs: cleanup assigning next active device with a check

[David Sterba]

On Mon, Apr 18, 2016 at 07:25:52PM +0800, Anand Jain wrote:
> Creates helper fucntion as needed by the device delete
> and replace operations. Also now it checks if the next
> device being assigned is an active device.
> 
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -1684,10 +1684,40 @@ out:
>  	return ret;
>  }
>  
> +struct btrfs_device *btrfs_find_next_active_device(struct btrfs_fs_devices *fs_devs,
> +					struct btrfs_device *device)

> +
> +void btrfs_assign_next_active_device(struct btrfs_fs_info *fs_info,
> +		struct btrfs_device *device, struct btrfs_device *this_dev)

Please add comments what the functions do so that one does not need to
read the whole function to figure it out.

[PATCH v2] btrfs: cleanup assigning next active device with a check

[Anand Jain]

Creates helper fucntion as needed by the device delete
and replace operations. Also now it checks if the next
device being assigned is an active device.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 v2: added comments, and BUG_ON if we can't find next_device.

 fs/btrfs/dev-replace.c |  8 +++----
 fs/btrfs/volumes.c     | 60 ++++++++++++++++++++++++++++++++++++--------------
 fs/btrfs/volumes.h     |  2 ++
 3 files changed, 48 insertions(+), 22 deletions(-)

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 6b37803a1a4a..50d0ed2fad2e 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -569,11 +569,9 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
 	ASSERT(list_empty(&src_device->resized_list));
 	tgt_device->commit_total_bytes = src_device->commit_total_bytes;
 	tgt_device->commit_bytes_used = src_device->bytes_used;
-	if (fs_info->sb->s_bdev &&
-		(fs_info->sb->s_bdev == src_device->bdev))
-		fs_info->sb->s_bdev = tgt_device->bdev;
-	if (fs_info->fs_devices->latest_bdev == src_device->bdev)
-		fs_info->fs_devices->latest_bdev = tgt_device->bdev;
+
+	btrfs_assign_next_active_device(fs_info, src_device, tgt_device);
+
 	list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list);
 	fs_info->fs_devices->rw_devices++;
 
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 5f70c1235466..0bb15da2da40 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1742,10 +1742,49 @@ out:
 	return ret;
 }
 
+struct btrfs_device *btrfs_find_next_active_device(struct btrfs_fs_devices *fs_devs,
+					struct btrfs_device *device)
+{
+	struct btrfs_device *next_device;
+
+	list_for_each_entry(next_device, &fs_devs->devices, dev_list) {
+		if (next_device != device &&
+			!next_device->missing && next_device->bdev)
+			return next_device;
+	}
+	return NULL;
+}
+
+/*
+ * Helper function to check if the given device is part of
+ * s_bdev / latest_bdev and replace it with the provided or
+ * the next active device, in the context where this function
+ * called, there should be always be another device which is
+ * active.
+ */
+void btrfs_assign_next_active_device(struct btrfs_fs_info *fs_info,
+		struct btrfs_device *device, struct btrfs_device *this_dev)
+{
+	struct btrfs_device *next_device;
+
+	if (this_dev)
+		next_device = this_dev;
+	else
+		next_device = btrfs_find_next_active_device(fs_info->fs_devices,
+								device);
+	BUG_ON(!next_device); /* Logic error */
+
+	if (fs_info->sb->s_bdev &&
+			(fs_info->sb->s_bdev == device->bdev))
+		fs_info->sb->s_bdev = next_device->bdev;
+
+	if (fs_info->fs_devices->latest_bdev == device->bdev)
+		fs_info->fs_devices->latest_bdev = next_device->bdev;
+}
+
 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 {
 	struct btrfs_device *device;
-	struct btrfs_device *next_device;
 	struct block_device *bdev;
 	struct buffer_head *bh = NULL;
 	struct btrfs_super_block *disk_super;
@@ -1896,13 +1935,7 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 	if (device->missing)
 		device->fs_devices->missing_devices--;
 
-	next_device = list_entry(root->fs_info->fs_devices->devices.next,
-				 struct btrfs_device, dev_list);
-	if (root->fs_info->sb->s_bdev &&
-		(root->fs_info->sb->s_bdev == device->bdev))
-		root->fs_info->sb->s_bdev = next_device->bdev;
-	if (device->bdev == root->fs_info->fs_devices->latest_bdev)
-		root->fs_info->fs_devices->latest_bdev = next_device->bdev;
+	btrfs_assign_next_active_device(root->fs_info, device, NULL);
 
 	if (device->bdev) {
 		device->fs_devices->open_devices--;
@@ -2069,8 +2102,6 @@ void btrfs_rm_dev_replace_free_srcdev(struct btrfs_fs_info *fs_info,
 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 				      struct btrfs_device *tgtdev)
 {
-	struct btrfs_device *next_device;
-
 	mutex_lock(&uuid_mutex);
 	WARN_ON(!tgtdev);
 	mutex_lock(&fs_info->fs_devices->device_list_mutex);
@@ -2082,13 +2113,8 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 
 	fs_info->fs_devices->num_devices--;
 
-	next_device = list_entry(fs_info->fs_devices->devices.next,
-				 struct btrfs_device, dev_list);
-	if (fs_info->sb->s_bdev &&
-		(tgtdev->bdev == fs_info->sb->s_bdev))
-		fs_info->sb->s_bdev = next_device->bdev;
-	if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
-		fs_info->fs_devices->latest_bdev = next_device->bdev;
+	btrfs_assign_next_active_device(fs_info, tgtdev, NULL);
+
 	list_del_rcu(&tgtdev->dev_list);
 
 	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 18c01739d46b..dbb018d82ec6 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -464,6 +464,8 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 			  struct btrfs_fs_devices **fs_devices_ret);
 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
 void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices, int step);
+void btrfs_assign_next_active_device(struct btrfs_fs_info *fs_info,
+		struct btrfs_device *device, struct btrfs_device *this_dev);
 int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
 					 char *device_path,
 					 struct btrfs_device **device);
-- 
2.7.0

Re: [PATCH] btrfs: cleanup assigning next active device with a check

[Anand Jain]

On 04/25/2016 11:15 PM, David Sterba wrote:
> On Mon, Apr 18, 2016 at 07:25:52PM +0800, Anand Jain wrote:
>> Creates helper fucntion as needed by the device delete
>> and replace operations. Also now it checks if the next
>> device being assigned is an active device.
>>
>> Signed-off-by: Anand Jain <anand.jain@oracle.com>
>> --- a/fs/btrfs/volumes.c
>> +++ b/fs/btrfs/volumes.c
>> @@ -1684,10 +1684,40 @@ out:
>>   	return ret;
>>   }
>>
>> +struct btrfs_device *btrfs_find_next_active_device(struct btrfs_fs_devices *fs_devs,
>> +					struct btrfs_device *device)
>
>> +
>> +void btrfs_assign_next_active_device(struct btrfs_fs_info *fs_info,
>> +		struct btrfs_device *device, struct btrfs_device *this_dev)
>
> Please add comments what the functions do so that one does not need to
> read the whole function to figure it out.

Right. Added comments. and BUG_ON(). Thanks,
Anand

> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

Re: [PATCH v2] btrfs: cleanup assigning next active device with a check

[David Sterba]

On Mon, May 02, 2016 at 07:02:08AM +0800, Anand Jain wrote:
> --- a/fs/btrfs/dev-replace.c
> +++ b/fs/btrfs/dev-replace.c
> @@ -569,11 +569,9 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
>  	ASSERT(list_empty(&src_device->resized_list));
>  	tgt_device->commit_total_bytes = src_device->commit_total_bytes;
>  	tgt_device->commit_bytes_used = src_device->bytes_used;
> -	if (fs_info->sb->s_bdev &&
> -		(fs_info->sb->s_bdev == src_device->bdev))
> -		fs_info->sb->s_bdev = tgt_device->bdev;

What's the base of this patch? The above code is not in my for-next so
I could be missing some important bits.

> -	if (fs_info->fs_devices->latest_bdev == src_device->bdev)
> -		fs_info->fs_devices->latest_bdev = tgt_device->bdev;
> +
> +	btrfs_assign_next_active_device(fs_info, src_device, tgt_device);
> +
>  	list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list);
>  	fs_info->fs_devices->rw_devices++;
>  
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index 5f70c1235466..0bb15da2da40 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -1742,10 +1742,49 @@ out:
>  	return ret;
>  }
>  
> +struct btrfs_device *btrfs_find_next_active_device(struct btrfs_fs_devices *fs_devs,
> +					struct btrfs_device *device)
> +{
> +	struct btrfs_device *next_device;
> +
> +	list_for_each_entry(next_device, &fs_devs->devices, dev_list) {
> +		if (next_device != device &&
> +			!next_device->missing && next_device->bdev)
> +			return next_device;
> +	}
> +	return NULL;
> +}
> +
> +/*
> + * Helper function to check if the given device is part of
> + * s_bdev / latest_bdev and replace it with the provided or
> + * the next active device, in the context where this function
> + * called, there should be always be another device which is
> + * active.
> + */
> +void btrfs_assign_next_active_device(struct btrfs_fs_info *fs_info,
> +		struct btrfs_device *device, struct btrfs_device *this_dev)
> +{
> +	struct btrfs_device *next_device;
> +
> +	if (this_dev)
> +		next_device = this_dev;
> +	else
> +		next_device = btrfs_find_next_active_device(fs_info->fs_devices,
> +								device);
> +	BUG_ON(!next_device); /* Logic error */

Please make it an ASSERT.

[PATCH] btrfs: cleanup assigning next active device with a check

[Anand Jain]

Creates helper fucntion as needed by the device delete
and replace operations. Also now it checks if the next
device being assigned is an active device.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 v3: fix compile warning, use ASSERT, minor comment update, based on for-next
 v2: added comments, and BUG_ON if we can't find next_device.

 fs/btrfs/dev-replace.c |  8 +++----
 fs/btrfs/volumes.c     | 60 ++++++++++++++++++++++++++++++++++++--------------
 fs/btrfs/volumes.h     |  2 ++
 3 files changed, 48 insertions(+), 22 deletions(-)

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 9706e8bf5f7c..5ec7fa860391 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -569,11 +569,9 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
 	ASSERT(list_empty(&src_device->resized_list));
 	tgt_device->commit_total_bytes = src_device->commit_total_bytes;
 	tgt_device->commit_bytes_used = src_device->bytes_used;
-	if (fs_info->sb->s_bdev &&
-		(fs_info->sb->s_bdev == src_device->bdev))
-		fs_info->sb->s_bdev = tgt_device->bdev;
-	if (fs_info->fs_devices->latest_bdev == src_device->bdev)
-		fs_info->fs_devices->latest_bdev = tgt_device->bdev;
+
+	btrfs_assign_next_active_device(fs_info, src_device, tgt_device);
+
 	list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list);
 	fs_info->fs_devices->rw_devices++;
 
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index c401ad4998fc..1bf382f8f88d 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1756,10 +1756,49 @@ static int btrfs_check_raid_min_devices(struct btrfs_fs_info *fs_info,
 	return 0;
 }
 
+struct btrfs_device *btrfs_find_next_active_device(struct btrfs_fs_devices *fs_devs,
+					struct btrfs_device *device)
+{
+	struct btrfs_device *next_device;
+
+	list_for_each_entry(next_device, &fs_devs->devices, dev_list) {
+		if (next_device != device &&
+			!next_device->missing && next_device->bdev)
+			return next_device;
+	}
+	return NULL;
+}
+
+/*
+ * Helper function to check if the given device is part of
+ * s_bdev / latest_bdev and replace it with the provided or
+ * the next active device, in the context where this function
+ * called, there should be always be another device (or this_dev)
+ * which is active.
+ */
+void btrfs_assign_next_active_device(struct btrfs_fs_info *fs_info,
+		struct btrfs_device *device, struct btrfs_device *this_dev)
+{
+	struct btrfs_device *next_device;
+
+	if (this_dev)
+		next_device = this_dev;
+	else
+		next_device = btrfs_find_next_active_device(fs_info->fs_devices,
+								device);
+	ASSERT(next_device);
+
+	if (fs_info->sb->s_bdev &&
+			(fs_info->sb->s_bdev == device->bdev))
+		fs_info->sb->s_bdev = next_device->bdev;
+
+	if (fs_info->fs_devices->latest_bdev == device->bdev)
+		fs_info->fs_devices->latest_bdev = next_device->bdev;
+}
+
 int btrfs_rm_device(struct btrfs_root *root, char *device_path, u64 devid)
 {
 	struct btrfs_device *device;
-	struct btrfs_device *next_device;
 	struct btrfs_fs_devices *cur_devices;
 	u64 num_devices;
 	int ret = 0;
@@ -1846,13 +1885,7 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path, u64 devid)
 	if (device->missing)
 		device->fs_devices->missing_devices--;
 
-	next_device = list_entry(root->fs_info->fs_devices->devices.next,
-				 struct btrfs_device, dev_list);
-	if (root->fs_info->sb->s_bdev &&
-		(root->fs_info->sb->s_bdev == device->bdev))
-		root->fs_info->sb->s_bdev = next_device->bdev;
-	if (device->bdev == root->fs_info->fs_devices->latest_bdev)
-		root->fs_info->fs_devices->latest_bdev = next_device->bdev;
+	btrfs_assign_next_active_device(root->fs_info, device, NULL);
 
 	if (device->bdev) {
 		device->fs_devices->open_devices--;
@@ -1982,8 +2015,6 @@ void btrfs_rm_dev_replace_free_srcdev(struct btrfs_fs_info *fs_info,
 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 				      struct btrfs_device *tgtdev)
 {
-	struct btrfs_device *next_device;
-
 	mutex_lock(&uuid_mutex);
 	WARN_ON(!tgtdev);
 	mutex_lock(&fs_info->fs_devices->device_list_mutex);
@@ -1995,13 +2026,8 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 
 	fs_info->fs_devices->num_devices--;
 
-	next_device = list_entry(fs_info->fs_devices->devices.next,
-				 struct btrfs_device, dev_list);
-	if (fs_info->sb->s_bdev &&
-		(tgtdev->bdev == fs_info->sb->s_bdev))
-		fs_info->sb->s_bdev = next_device->bdev;
-	if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
-		fs_info->fs_devices->latest_bdev = next_device->bdev;
+	btrfs_assign_next_active_device(fs_info, tgtdev, NULL);
+
 	list_del_rcu(&tgtdev->dev_list);
 
 	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 762d21996be1..0ac90f8d85bd 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -399,6 +399,8 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 			  struct btrfs_fs_devices **fs_devices_ret);
 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
 void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices, int step);
+void btrfs_assign_next_active_device(struct btrfs_fs_info *fs_info,
+		struct btrfs_device *device, struct btrfs_device *this_dev);
 int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
 					 char *device_path,
 					 struct btrfs_device **device);
-- 
2.7.0

Re: [PATCH v2] btrfs: cleanup assigning next active device with a check

[Anand Jain]

On 05/02/2016 11:26 PM, David Sterba wrote:
> On Mon, May 02, 2016 at 07:02:08AM +0800, Anand Jain wrote:
>> --- a/fs/btrfs/dev-replace.c
>> +++ b/fs/btrfs/dev-replace.c
>> @@ -569,11 +569,9 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
>>   	ASSERT(list_empty(&src_device->resized_list));
>>   	tgt_device->commit_total_bytes = src_device->commit_total_bytes;
>>   	tgt_device->commit_bytes_used = src_device->bytes_used;
>> -	if (fs_info->sb->s_bdev &&
>> -		(fs_info->sb->s_bdev == src_device->bdev))
>> -		fs_info->sb->s_bdev = tgt_device->bdev;
>
> What's the base of this patch?

  It was on master. But now the V3 which is based on your for-next.

> The above code is not in my for-next so
> I could be missing some important bits.

  Yes. That was added by this patch.

  [PATCH] btrfs: s_bdev is not null after missing replace

  While here can also integrate this.

  [PATCH 1/1] btrfs: fix lock dep warning move scratch super outside of 
chunk_mutex

------
git status
On branch for-next
Your branch is ahead of 'origin/for-next' by 3 commits.
(use "git push" to publish your local commits)
nothing to commit, working directory clean

git log --oneline | head -n 3
ac3fd7a65d23 btrfs: cleanup assigning next active device with a check
0fbd788ec3d9 btrfs: s_bdev is not null after missing replace
8362f084ffd6 btrfs: fix lock dep warning move scratch super outside of 
chunk_mutex
-----

I have run xfstests on for-next I don't see any unusual failures.


Thanks,
Anand


>> -	if (fs_info->fs_devices->latest_bdev == src_device->bdev)
>> -		fs_info->fs_devices->latest_bdev = tgt_device->bdev;
>> +
>> +	btrfs_assign_next_active_device(fs_info, src_device, tgt_device);
>> +
>>   	list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list);
>>   	fs_info->fs_devices->rw_devices++;
>>
>> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
>> index 5f70c1235466..0bb15da2da40 100644
>> --- a/fs/btrfs/volumes.c
>> +++ b/fs/btrfs/volumes.c
>> @@ -1742,10 +1742,49 @@ out:
>>   	return ret;
>>   }
>>
>> +struct btrfs_device *btrfs_find_next_active_device(struct btrfs_fs_devices *fs_devs,
>> +					struct btrfs_device *device)
>> +{
>> +	struct btrfs_device *next_device;
>> +
>> +	list_for_each_entry(next_device, &fs_devs->devices, dev_list) {
>> +		if (next_device != device &&
>> +			!next_device->missing && next_device->bdev)
>> +			return next_device;
>> +	}
>> +	return NULL;
>> +}
>> +
>> +/*
>> + * Helper function to check if the given device is part of
>> + * s_bdev / latest_bdev and replace it with the provided or
>> + * the next active device, in the context where this function
>> + * called, there should be always be another device which is
>> + * active.
>> + */
>> +void btrfs_assign_next_active_device(struct btrfs_fs_info *fs_info,
>> +		struct btrfs_device *device, struct btrfs_device *this_dev)
>> +{
>> +	struct btrfs_device *next_device;
>> +
>> +	if (this_dev)
>> +		next_device = this_dev;
>> +	else
>> +		next_device = btrfs_find_next_active_device(fs_info->fs_devices,
>> +								device);
>> +	BUG_ON(!next_device); /* Logic error */
>
> Please make it an ASSERT.
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

Re: [PATCH v2] btrfs: cleanup assigning next active device with a check

[David Sterba]

On Tue, May 03, 2016 at 06:01:31PM +0800, Anand Jain wrote:
> 
> 
> On 05/02/2016 11:26 PM, David Sterba wrote:
> > On Mon, May 02, 2016 at 07:02:08AM +0800, Anand Jain wrote:
> >> --- a/fs/btrfs/dev-replace.c
> >> +++ b/fs/btrfs/dev-replace.c
> >> @@ -569,11 +569,9 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
> >>   	ASSERT(list_empty(&src_device->resized_list));
> >>   	tgt_device->commit_total_bytes = src_device->commit_total_bytes;
> >>   	tgt_device->commit_bytes_used = src_device->bytes_used;
> >> -	if (fs_info->sb->s_bdev &&
> >> -		(fs_info->sb->s_bdev == src_device->bdev))
> >> -		fs_info->sb->s_bdev = tgt_device->bdev;
> >
> > What's the base of this patch?
> 
>   It was on master. But now the V3 which is based on your for-next.
> 
> > The above code is not in my for-next so
> > I could be missing some important bits.
> 
>   Yes. That was added by this patch.
> 
>   [PATCH] btrfs: s_bdev is not null after missing replace

Ah, that's the one. Added to next together with v3, though a testcase is
still desirable.

>   While here can also integrate this.
> 
>   [PATCH 1/1] btrfs: fix lock dep warning move scratch super outside of 
> chunk_mutex

That one has been in for-next for some time.

Re: [PATCH v2] btrfs: cleanup assigning next active device with a check

[Anand Jain]

>>    While here can also integrate this.
>>
>>    [PATCH 1/1] btrfs: fix lock dep warning move scratch super outside of
>> chunk_mutex
>
> That one has been in for-next for some time.

There is another patch which is similarly named (sorry about that),
I see that one but not this.

---------
git log -i --author=anand.jain@oracle.com --oneline  | egrep "btrfs: fix 
lock dep"
58681ad85b9f btrfs: fix lock dep warning, move scratch dev out of 
device_list_mutex and uuid_mutex

git status
On branch for-next
Your branch is up-to-date with 'origin/for-next'.
nothing to commit, working directory clean
----------

Thanks, Anand

Re: [PATCH v2] btrfs: cleanup assigning next active device with a check

[David Sterba]

On Tue, May 03, 2016 at 07:47:28PM +0200, David Sterba wrote:
> On Tue, May 03, 2016 at 06:01:31PM +0800, Anand Jain wrote:
> > 
> > 
> > On 05/02/2016 11:26 PM, David Sterba wrote:
> > > On Mon, May 02, 2016 at 07:02:08AM +0800, Anand Jain wrote:
> > >> --- a/fs/btrfs/dev-replace.c
> > >> +++ b/fs/btrfs/dev-replace.c
> > >> @@ -569,11 +569,9 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
> > >>   	ASSERT(list_empty(&src_device->resized_list));
> > >>   	tgt_device->commit_total_bytes = src_device->commit_total_bytes;
> > >>   	tgt_device->commit_bytes_used = src_device->bytes_used;
> > >> -	if (fs_info->sb->s_bdev &&
> > >> -		(fs_info->sb->s_bdev == src_device->bdev))
> > >> -		fs_info->sb->s_bdev = tgt_device->bdev;
> > >
> > > What's the base of this patch?
> > 
> >   It was on master. But now the V3 which is based on your for-next.
> > 
> > > The above code is not in my for-next so
> > > I could be missing some important bits.
> > 
> >   Yes. That was added by this patch.
> > 
> >   [PATCH] btrfs: s_bdev is not null after missing replace
> 
> Ah, that's the one. Added to next together with v3, though a testcase is
> still desirable.

There were some merge conflicts with the dev-del-by-id patchset so I've
put the patches there.

Re: [PATCH v2] btrfs: cleanup assigning next active device with a check

[David Sterba]

On Wed, May 04, 2016 at 07:31:55AM +0800, Anand Jain wrote:
> 
> >>    While here can also integrate this.
> >>
> >>    [PATCH 1/1] btrfs: fix lock dep warning move scratch super outside of
> >> chunk_mutex
> >
> > That one has been in for-next for some time.
> 
> There is another patch which is similarly named (sorry about that),
> I see that one but not this.
> 
> ---------
> git log -i --author=anand.jain@oracle.com --oneline  | egrep "btrfs: fix 
> lock dep"
> 58681ad85b9f btrfs: fix lock dep warning, move scratch dev out of 
> device_list_mutex and uuid_mutex

I see, the subjects partially differ in the last word, that's easy to
miss and I got te 'chunk_mutex' patch marked as dropped as it looked
like the other patch superseded it.

https://patchwork.kernel.org/patch/8868771/ -- in next

https://patchwork.kernel.org/patch/8810591/ -- pending