On 2017年09月23日 09:27, Satoru Takeuchi wrote:
At Sat, 23 Sep 2017 10:19:26 +0900,
Satoru Takeuchi wrote:
At Wed, 20 Sep 2017 15:18:43 +0900,
Qu Wenruo wrote:
Commit 7dfb8be11b5d ("btrfs: Round down values which are written for
total_bytes_size") is fixing the unaligned device size caused by
adding/shrinking device.
It added a new WARN_ON() when device size is unaligned.
This is fine for new device added to btrfs using v4.13 kernel, but not
existing device whose total_bytes is already unaligned.
And the WARN_ON() will get triggered every time a block group get
created/removed on the unaligned device.
This patch will remove the WARN_ON(), and warn user more gently what's
happening and how to fix it.
Reported-by: Rich Rauenzahn <r...@shroop.net>
Fixes: 7dfb8be11b5d ("btrfs: Round down values which are written for
total_bytes_size")
Signed-off-by: Qu Wenruo <quwenruo.bt...@gmx.com>
---
fs/btrfs/ctree.h | 1 -
fs/btrfs/volumes.c | 16 ++++++++++++----
2 files changed, 12 insertions(+), 5 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 5a8933da39a7..4de9269e435a 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1562,7 +1562,6 @@ static inline void btrfs_set_device_total_bytes(struct
extent_buffer *eb,
{
BUILD_BUG_ON(sizeof(u64) !=
sizeof(((struct btrfs_dev_item *)0))->total_bytes);
- WARN_ON(!IS_ALIGNED(val, eb->fs_info->sectorsize));
btrfs_set_64(eb, s, offsetof(struct btrfs_dev_item, total_bytes), val);
}
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 0e8f16c305df..afae25df6a8c 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6472,15 +6472,23 @@ static int read_one_chunk(struct btrfs_fs_info
*fs_info, struct btrfs_key *key,
return 0;
}
-static void fill_device_from_item(struct extent_buffer *leaf,
- struct btrfs_dev_item *dev_item,
- struct btrfs_device *device)
+static void fill_device_from_item(struct btrfs_fs_info *fs_info,
+ struct extent_buffer *leaf,
+ struct btrfs_dev_item *dev_item,
+ struct btrfs_device *device)
{
unsigned long ptr;
device->devid = btrfs_device_id(leaf, dev_item);
device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
device->total_bytes = device->disk_total_bytes;
+ if (!IS_ALIGNED(device->total_bytes, fs_info->sectorsize)) {
+ btrfs_warn(fs_info,
+ "devid %llu has unaligned total bytes %llu",
+ device->devid, device->disk_total_bytes);
+ btrfs_warn(fs_info,
+ "please shrink the device a little and resize back to fix
it");
+ }
How about telling uses to know device->total_bytes should be alligned
to fs_info->sectorsize here?
Thanks,
I should make my comment clearer, sorry.
===
+ if (!IS_ALIGNED(device->total_bytes, fs_info->sectorsize)) {
+ btrfs_warn(fs_info,
+ "devid %llu: total bytes %llu should be aligned to %u
bytes",
+ device->devid, device->disk_total_bytes,
fs_info->sectorsize);
+ btrfs_warn(fs_info,
+ "please shrink the device a little and resize back to fix
it");
+ }
===
That's better.
But I'm also considering modifying the total_bytes directly here.
So that any time DEV_ITEM and super block get updated, new aligned value
will be written back to disk, and since the value is aligned in memory,
it won't cause WARN_ON() any longer.
I'll test and check the code for confirmation before updating the patch.
Thanks,
Qu
Thanks,
Satoru
Satoru
device->commit_total_bytes = device->disk_total_bytes;
device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
device->commit_bytes_used = device->bytes_used;
@@ -6625,7 +6633,7 @@ static int read_one_dev(struct btrfs_fs_info *fs_info,
return -EINVAL;
}
- fill_device_from_item(leaf, dev_item, device);
+ fill_device_from_item(fs_info, leaf, dev_item, device);
device->in_fs_metadata = 1;
if (device->writeable && !device->is_tgtdev_for_dev_replace) {
device->fs_devices->total_rw_bytes += device->total_bytes;
--
2.14.1
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