btrfs: stable backport for multidevice btrfs zone (de)activation

Hi Greg,

Here's the backport for btrfs' multidevice zone (de)activation that failed to apply to your v6.1 branch.

Johannes Thumshirn (2):
btrfs: zoned: fix zone activation with missing devices
btrfs: zoned: fix zone finishing with missing devices

 fs/btrfs/zoned.c | 6 ++++++
 1 file changed, 6 insertions(+)

2.43.0

From: Johannes Thumshirn <[email protected]>

commit 2bbc4a45e5eb6b868357c1045bf6f38f6ba576e0 upstream

If btrfs_zone_activate() is called with a filesystem that has missing devices (e.g. a RAID file system mounted in degraded mode) it is accessing the btrfs_device::zone_info pointer, which will not be set if the device in question is missing.

Check if the device is present (by checking if it has a valid block device pointer associated) and if not, skip zone activation for it.

---
 fs/btrfs/zoned.c | 3 +++
 1 file changed, 3 insertions(+)

index 794526ab90d2..46aadef5a463 100644
@@ -1909,6 +1909,9 @@ bool btrfs_zone_activate(struct btrfs_block_group *block_group)
 		device = map->stripes[i].dev;
 		physical = map->stripes[i].physical;
 
+		if (!device->bdev)
+			continue;
+
 		if (device->zone_info->max_active_zones == 0)
 			continue;
 

2.43.0

From: Johannes Thumshirn <[email protected]>

commit 35fec1089ebb5617f85884d3fa6a699ce6337a75 upstream

If do_zone_finish() is called with a filesystem that has missing devices (e.g. a RAID file system mounted in degraded mode) it is accessing the btrfs_device::zone_info pointer, which will not be set if the device in question is missing.

Check if the device is present (by checking if it has a valid block device pointer associated) and if not, skip zone finishing for it.

---
 fs/btrfs/zoned.c | 3 +++
 1 file changed, 3 insertions(+)

index 46aadef5a463..1dff64e62047 100644
@@ -2055,6 +2055,9 @@ static int do_zone_finish(struct btrfs_block_group *block_group, bool fully_writ
 		struct btrfs_device *device = map->stripes[i].dev;
 		const u64 physical = map->stripes[i].physical;
 
+		if (!device->bdev)
+			continue;
+
 		if (device->zone_info->max_active_zones == 0)
 			continue;
 

2.43.0

[ Sasha's backport helper bot ]

Hi,

✅ All tests passed successfully. No issues detected. No action required from the submitter.

The upstream commit SHA1 provided is correct: 2bbc4a45e5eb6b868357c1045bf6f38f6ba576e0

WARNING: Author mismatch between patch and upstream commit:
Backport author: Johannes Thumshirn<[email protected]> Commit author: Johannes Thumshirn<[email protected]>

Status in newer kernel trees:

6.14.y | Not found
6.13.y | Not found
6.12.y | Not found

6.6.y | Not found

Note: The patch differs from the upstream commit:
---

1:  2bbc4a45e5eb6 < -:  ------------- btrfs: zoned: fix zone activation with missing devices
-:  ------------- > 1:  abb5ad2758783 btrfs: zoned: fix zone activation with missing devices

---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.1.y        |  Success    |  Success   |

[ Sasha's backport helper bot ]

Hi,

✅ All tests passed successfully. No issues detected. No action required from the submitter.

The upstream commit SHA1 provided is correct: 35fec1089ebb5617f85884d3fa6a699ce6337a75

WARNING: Author mismatch between patch and upstream commit:
Backport author: Johannes Thumshirn<[email protected]> Commit author: Johannes Thumshirn<[email protected]>

Status in newer kernel trees:

6.14.y | Not found
6.13.y | Not found
6.12.y | Not found

6.6.y | Not found

Note: The patch differs from the upstream commit:
---

1:  35fec1089ebb5 < -:  ------------- btrfs: zoned: fix zone finishing with missing devices
-:  ------------- > 1:  a47a1104867b3 btrfs: zoned: fix zone finishing with missing devices

---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y        |  Success    |  Success   |