We got an internal report about a file system not wanting to mount
following 99e3ecfcb9f4 ("Btrfs: add more validation checks for superblock").
BTRFS error (device sdb1): super_total_bytes 1000203816960 mismatch with
fs_devices total_rw_bytes 1000203820544
Substracting the numbers we get a difference of less than a 4kb. Upon closer
inspection it became apparent that mkfs actually rounds down the size of the
device to a multiple of sector size. However, the same cannot be said for
various functions which modify the total size and are called from btrfs_balanace
as well as when adding a new device. So this patch ensures that values being
saved into on-disk data structures are always rounded down to a multiple of
sectorsize
Signed-off-by: Nikolay Borisov <nborisov@xxxxxxxx>
---
fs/btrfs/ctree.h | 1 +
fs/btrfs/volumes.c | 18 +++++++++++++-----
2 files changed, 14 insertions(+), 5 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index ce4929ad5914..a75a23f9d68e 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1567,6 +1567,7 @@ 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 e37f95976443..adf32f46a73f 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2387,7 +2387,8 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
device->io_width = fs_info->sectorsize;
device->io_align = fs_info->sectorsize;
device->sector_size = fs_info->sectorsize;
- device->total_bytes = i_size_read(bdev->bd_inode);
+ device->total_bytes = round_down(i_size_read(bdev->bd_inode),
+ fs_info->sectorsize);
device->disk_total_bytes = device->total_bytes;
device->commit_total_bytes = device->total_bytes;
device->fs_info = fs_info;
@@ -2424,7 +2425,7 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
tmp = btrfs_super_total_bytes(fs_info->super_copy);
btrfs_set_super_total_bytes(fs_info->super_copy,
- tmp + device->total_bytes);
+ round_down(tmp + device->total_bytes, fs_info->sectorsize));
tmp = btrfs_super_num_devices(fs_info->super_copy);
btrfs_set_super_num_devices(fs_info->super_copy, tmp + 1);
@@ -2687,6 +2688,8 @@ int btrfs_grow_device(struct btrfs_trans_handle *trans,
if (!device->writeable)
return -EACCES;
+ new_size = round_down(new_size, fs_info->sectorsize);
+
mutex_lock(&fs_info->chunk_mutex);
old_total = btrfs_super_total_bytes(super_copy);
diff = new_size - device->total_bytes;
@@ -2699,7 +2702,8 @@ int btrfs_grow_device(struct btrfs_trans_handle *trans,
fs_devices = fs_info->fs_devices;
- btrfs_set_super_total_bytes(super_copy, old_total + diff);
+ btrfs_set_super_total_bytes(super_copy,
+ round_down(old_total + diff, fs_info->sectorsize));
device->fs_devices->total_rw_bytes += diff;
btrfs_device_set_total_bytes(device, new_size);
@@ -4389,7 +4393,10 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
struct btrfs_super_block *super_copy = fs_info->super_copy;
u64 old_total = btrfs_super_total_bytes(super_copy);
u64 old_size = btrfs_device_get_total_bytes(device);
- u64 diff = old_size - new_size;
+ u64 diff;
+
+ new_size = round_down(new_size, fs_info->sectorsize);
+ diff = old_size - new_size;
if (device->is_tgtdev_for_dev_replace)
return -EINVAL;
@@ -4516,7 +4523,8 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
&fs_info->fs_devices->resized_devices);
WARN_ON(diff > old_total);
- btrfs_set_super_total_bytes(super_copy, old_total - diff);
+ btrfs_set_super_total_bytes(super_copy,
+ round_down(old_total - diff, fs_info->sectorsize));
mutex_unlock(&fs_info->chunk_mutex);
/* Now btrfs_update_device() will change the on-disk size. */
--
2.7.4
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