This patch corrects open-coded inode_map iteration, which happens to be
illegal in new libext2fs due to inode_map being private, causing warning,
which becomes a compile error.
Many options were not mentioned in the usage message, fix that and
cleaning up the brackets
Signed-Off-By: Ahmed Kamal <email.ahmedkamal@googlemail.com>
btrfsctl -c forces a single FS sync
The transaction ioctls are unsafe for general use because they can lead
to deadlocks if the application is not very careful. But, ceph is
experimenting with btrfs as a backing store, and these ioctls are required
for testing.
Gcc only sends warnings for uninitialized variables when you compile with -O,
and there were a couple of bugs sprinkled in the code. The biggest was the
alloc_start variable for mkfs, which can cause strange things to happen.
(thanks to Gabor Micsko for helping to find this)
This patch add ext2_inode.i_size_high into account when calculating regular
file's size in btrfs-convert, which makes it deal with large files bigger than
4GB properly.
This is a utility option for the resizer, it makes sure to allocate
at offset bytes in the disk or higher. It ensures the resizer will have
something to move when testing it.
This patch improves converter's allocator and fixes a bug in data relocation
function. The new allocator caches free blocks as Btrfs's default allocator.
In testing here, the user CPU time reduced to half of the original when
checksum and small file packing was disabled. This patch also enlarges the
size of block groups created by the converter.
balance level starts by trying to empty the middle block, and then
pushes from the right to the middle. This might empty the right block
and leave a small number of pointers in the middle.
The main changes in this patch are adding chunk handing and data relocation
ability. In the last step of conversion, the converter relocates data in system
chunk and move chunk tree into system chunk. In the rollback process, the
converter remove chunk tree from system chunk and copy data back.
Regards
YZ
---
Block headers now store the chunk tree uuid
Chunk items records the device uuid for each stripes
Device extent items record better back refs to the chunk tree
Block groups record better back refs to the chunk tree
The chunk tree format has also changed. The objectid of BTRFS_CHUNK_ITEM_KEY
used to be the logical offset of the chunk. Now it is a chunk tree id,
with the logical offset being stored in the offset field of the key.
This allows a single chunk tree to record multiple logical address spaces,
upping the number of bytes indexed by a chunk tree from 2^64 to
2^128.
When a block is freed, it can be immediately reused if it is from
the current transaction. But, an extra check is required to make sure
the block had not been written yet. If it were reused after being written,
the transid in the block header might match the transid of the
next time the block was allocated.
The parent node records the transaction ID of the block it is pointing to,
and this is used as part of validating the block on reads. So, there
can only be one version of a block per transaction.
The mkfs code bootstraps the filesystem on a single device. Once
the raid block groups are setup, it needs to recow all of the blocks so
that each tree is properly allocated.
mkfs.btrfs --data {raid0,raid1,single}
mkfs.btrfs --metadata {raid0,raid1,single}
In single mode, no extra duplication or striping is done.
In raid0 mode, blocks are spread across all of the available devices
In raid1 mode, blocks are mirrored across two devices.
For metadata, if raid1 is used and there is only one device, the
metadata is duplicated on that single spindle.
The defaults are raid0 for data and raid1 for metadata
Chris Mason