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path: root/fs/btrfs/ioctl.h
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2009-01-16Btrfs: fix ioctl arg size (userland incompatible change!)Chris Mason
The structure used to send device in btrfs ioctl calls was not properly aligned, and so 32 bit ioctls would not work properly on 64 bit kernels. We could fix this with compat ioctls, but we're just one byte away and it doesn't make sense at this stage to carry about the compat ioctls forever at this stage in the project. This patch brings the ioctl arg up to an evenly aligned 4k. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-11-17Btrfs: Allow subvolumes and snapshots anywhere in the directory treeChris Mason
Before, all snapshots and subvolumes lived in a single flat directory. This was awkward and confusing because the single flat directory was only writable with the ioctls. This commit changes the ioctls to create subvols and snapshots at any point in the directory tree. This requires making separate ioctls for snapshot and subvol creation instead of a combining them into one. The subvol ioctl does: btrfsctl -S subvol_name parent_dir After the ioctl is done subvol_name lives inside parent_dir. The snapshot ioctl does: btrfsctl -s path_for_snapshot root_to_snapshot path_for_snapshot can be an absolute or relative path. btrfsctl breaks it up into directory and basename components. root_to_snapshot can be any file or directory in the FS. The snapshot is taken of the entire root where that file lives. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-11-12Btrfs: allow clone of an arbitrary file rangeSage Weil
This patch adds an additional CLONE_RANGE ioctl to clone an arbitrary (block-aligned) file range to another file. The original CLONE ioctl becomes a special case of cloning the entire file range. The logic is a bit more complex now since ranges may be cloned to different offsets, and because we may only be cloning the beginning or end of a particular extent or checksum item. An additional sanity check ensures the source and destination files aren't the same (which would previously deadlock), although eventually this could be extended to allow the duplication of file data at a different offset within the same file. Any extents within the destination range in the target file are dropped. We currently do not cope with the case where a compressed inline extent needs to be split. This will probably require decompressing the extent into a temporary address_space, and inserting just the cloned portion as a new compressed inline extent. For now, just return -EINVAL in this case. Note that this never comes up in the more common case of cloning an entire file. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: transaction ioctlsSage Weil
These ioctls let a user application hold a transaction open while it performs a series of operations. A final ioctl does a sync on the fs (closing the current transaction). This is the main requirement for Ceph's OSD to be able to keep the data it's storing in a btrfs volume consistent, and AFAICS it works just fine. The application would do something like fd = ::open("some/file", O_RDONLY); ::ioctl(fd, BTRFS_IOC_TRANS_START); /* do a bunch of stuff */ ::ioctl(fd, BTRFS_IOC_TRANS_END); or just ::close(fd); And to ensure it commits to disk, ::ioctl(fd, BTRFS_IOC_SYNC); When a transaction is held open, the trans_handle is attached to the struct file (via private_data) so that it will get cleaned up if the process dies unexpectedly. A held transaction is also ended on fsync() to avoid a deadlock. A misbehaving application could also deliberately hold a transaction open, effectively locking up the FS, so it may make sense to restrict something like this to root or something. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Clone file data ioctlSage Weil
Add a new ioctl to clone file data Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Add new ioctl to add devicesChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Add support for device scanning and detection ioctlsChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Support for online FS resize (grow and shrink)Chris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-08-07Btrfs: Add run time btree defrag, and an ioctl to force btree defragChris Mason
This adds two types of btree defrag, a run time form that tries to defrag recently allocated blocks in the btree when they are still in ram, and an ioctl that forces defrag of all btree blocks. File data blocks are not defragged yet, but this can make a huge difference in sequential btree reads. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-06-12Btrfs: add GPLv2Chris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-04-12Btrfs: add disk ioctl, mostly workingChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-04-10Btrfs: snapshot progressChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>