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path: root/fs/btrfs/ioctl.c
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2009-02-20Btrfs: add better -ENOSPC handlingJosef Bacik
This is a step in the direction of better -ENOSPC handling. Instead of checking the global bytes counter we check the space_info bytes counters to make sure we have enough space. If we don't we go ahead and try to allocate a new chunk, and then if that fails we return -ENOSPC. This patch adds two counters to btrfs_space_info, bytes_delalloc and bytes_may_use. bytes_delalloc account for extents we've actually setup for delalloc and will be allocated at some point down the line. bytes_may_use is to keep track of how many bytes we may use for delalloc at some point. When we actually set the extent_bit for the delalloc bytes we subtract the reserved bytes from the bytes_may_use counter. This keeps us from not actually being able to allocate space for any delalloc bytes. Signed-off-by: Josef Bacik <jbacik@redhat.com>
2009-01-21Btrfs: removed unused #include <version.h>'sHuang Weiyi
Removed unused #include <version.h>'s in btrfs Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-01-05Btrfs: Fix checkpatch.pl warningsChris Mason
There were many, most are fixed now. struct-funcs.c generates some warnings but these are bogus. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-01-05Btrfs: update directory's size when creating subvol/snapshotYan Zheng
Make sure directory's size properly updated when creating subvol/snapshot. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2009-01-05Btrfs: add permission checks to the ioctlsChris Mason
Only root can add/remove devices Only root can defrag subtrees Only files open for writing can be defragged Only files open for writing can be the destination for a clone Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-12-19Btrfs: Add missing mnt_drop_write in ioctl.cYan Zheng
This patch adds the missing mnt_drop_write to match mnt_want_write in btrfs_ioctl_defrag and btrfs_ioctl_clone Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-12-11Btrfs: fix leaking block group on balanceYan Zheng
The block group structs are referenced in many different places, and it's not safe to free while balancing. So, those block group structs were simply leaked instead. This patch replaces the block group pointer in the inode with the starting byte offset of the block group and adds reference counting to the block group struct. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-12-11Btrfs: mnt_drop_write in ioctl_trans_endSage Weil
Add missing mnt_drop_write to match the mnt_want_write in btrfs_ioctl_trans_start. Signed-off-by: Sage Weil <sage@newdream.net>
2008-12-08Btrfs: move data checksumming into a dedicated treeChris Mason
Btrfs stores checksums for each data block. Until now, they have been stored in the subvolume trees, indexed by the inode that is referencing the data block. This means that when we read the inode, we've probably read in at least some checksums as well. But, this has a few problems: * The checksums are indexed by logical offset in the file. When compression is on, this means we have to do the expensive checksumming on the uncompressed data. It would be faster if we could checksum the compressed data instead. * If we implement encryption, we'll be checksumming the plain text and storing that on disk. This is significantly less secure. * For either compression or encryption, we have to get the plain text back before we can verify the checksum as correct. This makes the raid layer balancing and extent moving much more expensive. * It makes the front end caching code more complex, as we have touch the subvolume and inodes as we cache extents. * There is potentitally one copy of the checksum in each subvolume referencing an extent. The solution used here is to store the extent checksums in a dedicated tree. This allows us to index the checksums by phyiscal extent start and length. It means: * The checksum is against the data stored on disk, after any compression or encryption is done. * The checksum is stored in a central location, and can be verified without following back references, or reading inodes. This makes compression significantly faster by reducing the amount of data that needs to be checksummed. It will also allow much faster raid management code in general. The checksums are indexed by a key with a fixed objectid (a magic value in ctree.h) and offset set to the starting byte of the extent. This allows us to copy the checksum items into the fsync log tree directly (or any other tree), without having to invent a second format for them. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-12-02Btrfs: add support for multiple csum algorithmsJosef Bacik
This patch gives us the space we will need in order to have different csum algorithims at some point in the future. We save the csum algorithim type in the superblock, and use those instead of define's. Signed-off-by: Josef Bacik <jbacik@redhat.com>
2008-12-02Btrfs: btrfs: pass void __user * to btrfs_ioctl_clone_rangeChristoph Hellwig
Cleans the code up a little and also avoids a sparse warning due to the incorrect cast in the current version of the code. Signed-off-by: Christoph Hellwig <hch@lst.de>
2008-12-02Btrfs: clean up btrfs_ioctl a little bitChristoph Hellwig
Provide a void __user *argp pointer so that we can avoid duplicating the cast for various sub-command calls. Signed-off-by: Christoph Hellwig <hch@lst.de>
2008-12-02Btrfs: make things static and include the right headersChristoph Hellwig
Shut up various sparse warnings about symbols that should be either static or have their declarations in scope. Signed-off-by: Christoph Hellwig <hch@lst.de>
2008-12-02Btrfs: remove unneeded btrfs_start_delalloc_inodes callSage Weil
It is called by btrfs_sync_fs. Signed-off-by: Sage Weil <sage@newdream.net>
2008-11-20Btrfs: compat code fixesChris Mason
The btrfs git kernel trees is used to build a standalone tree for compiling against older kernels. This commit makes the standalone tree work with 2.6.27 Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-11-17Btrfs: prevent loops in the directory tree when creating snapshotsChris Mason
For a directory tree: /mnt/subvolA/subvolB btrfsctl -s /mnt/subvolA/subvolB /mnt Will create a directory loop with subvolA under subvolB. This commit uses the forward refs for each subvol and snapshot to error out before creating the loop. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-11-17Btrfs: Add backrefs and forward refs for subvols and snapshotsChris Mason
Subvols and snapshots can now be referenced from any point in the directory tree. We need to maintain back refs for them so we can find lost subvols. Forward refs are added so that we know all of the subvols and snapshots referenced anywhere in the directory tree of a single subvol. This can be used to do recursive snapshotting (but they aren't yet) and it is also used to detect and prevent directory loops when creating new snapshots. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-11-17Btrfs: Give each subvol and snapshot their own anonymous devidChris Mason
Each subvolume has its own private inode number space, and so we need to fill in different device numbers for each subvolume to avoid confusing applications. This commit puts a struct super_block into struct btrfs_root so it can call set_anon_super() and get a different device number generated for each root. btrfs_rename is changed to prevent renames across subvols. 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>
2008-11-17Btrfs: Seed device supportYan Zheng
Seed device is a special btrfs with SEEDING super flag set and can only be mounted in read-only mode. Seed devices allow people to create new btrfs on top of it. The new FS contains the same contents as the seed device, but it can be mounted in read-write mode. This patch does the following: 1) split code in btrfs_alloc_chunk into two parts. The first part does makes the newly allocated chunk usable, but does not do any operation that modifies the chunk tree. The second part does the the chunk tree modifications. This division is for the bootstrap step of adding storage to the seed device. 2) Update device management code to handle seed device. The basic idea is: For an FS grown from seed devices, its seed devices are put into a list. Seed devices are opened on demand at mounting time. If any seed device is missing or has been changed, btrfs kernel module will refuse to mount the FS. 3) make btrfs_find_block_group not return NULL when all block groups are read-only. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-11-12Btrfs: mount ro and remount supportYan Zheng
This patch adds mount ro and remount support. The main changes in patch are: adding btrfs_remount and related helper function; splitting the transaction related code out of close_ctree into btrfs_commit_super; updating allocator to properly handle read only block group. Signed-off-by: Yan Zheng <zheng.yan@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>
2008-10-30Btrfs: Add fallocate support v2Yan Zheng
This patch updates btrfs-progs for fallocate support. fallocate is a little different in Btrfs because we need to tell the COW system that a given preallocated extent doesn't need to be cow'd as long as there are no snapshots of it. This leverages the -o nodatacow checks. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-10-30Btrfs: update nodatacow code v2Yan Zheng
This patch simplifies the nodatacow checker. If all references were created after the latest snapshot, then we can avoid COW safely. This patch also updates run_delalloc_nocow to do more fine-grained checking. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-10-29Btrfs: Add root tree pointer transaction idsYan Zheng
This patch adds transaction IDs to root tree pointers. Transaction IDs in tree pointers are compared with the generation numbers in block headers when reading root blocks of trees. This can detect some types of IO errors. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-10-10Btrfs: Don't call security_inode_mkdir during subvol creationChris Mason
Subvol creation already requires privs, and security_inode_mkdir isn't exported. For now we don't need it. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-10-09Btrfs: Fix subvolume creation locking rulesChristoph Hellwig
Creating a subvolume is in many ways like a normal VFS ->mkdir, and we really need to play with the VFS topology locking rules. So instead of just creating the snapshot on disk and then later getting rid of confliting aliases do it correctly from the start. This will become especially important once we allow for subvolumes anywhere in the tree, and not just below a hidden root. Note that snapshots will need the same treatment, but do to the delay in creating them we can't do it currently. Chris promised to fix that issue, so I'll wait on that. Signed-off-by: Christoph Hellwig <hch@lst.de>
2008-10-09Btrfs: Remove offset field from struct btrfs_extent_refYan Zheng
The offset field in struct btrfs_extent_ref records the position inside file that file extent is referenced by. In the new back reference system, tree leaves holding references to file extent are recorded explicitly. We can scan these tree leaves very quickly, so the offset field is not required. This patch also makes the back reference system check the objectid when extents are in deleting. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-10-09Btrfs: Count space allocated to file in bytesYan Zheng
This patch makes btrfs count space allocated to file in bytes instead of 512 byte sectors. Everything else in btrfs uses a byte count instead of sector sizes or blocks sizes, so this fits better. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-09-26Btrfs: extent_map and data=ordered fixes for space balancingZheng Yan
* Add an EXTENT_BOUNDARY state bit to keep the writepage code from merging data extents that are in the process of being relocated. This allows us to do accounting for them properly. * The balancing code relocates data extents indepdent of the underlying inode. The extent_map code was modified to properly account for things moving around (invalidating extent_map caches in the inode). * Don't take the drop_mutex in the create_subvol ioctl. It isn't required. * Fix walking of the ordered extent list to avoid races with sys_unlink * Change the lock ordering rules. Transaction start goes outside the drop_mutex. This allows btrfs_commit_transaction to directly drop the relocation trees. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Full back reference supportZheng Yan
This patch makes the back reference system to explicit record the location of parent node for all types of extents. The location of parent node is placed into the offset field of backref key. Every time a tree block is balanced, the back references for the affected lower level extents are updated. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: trivial sparse fixesChristoph Hellwig
Fix a bunch of trivial sparse complaints. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Fix nodatacow for the new data=ordered modeYan Zheng
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Update clone file ioctlYan Zheng
This patch updates the file clone ioctl for the tree locking and new data ordered code. --- Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Maintain a list of inodes that are delalloc and a way to wait on themChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: fix ioctl-initiated transactions vs wait_current_trans()Sage Weil
Commit 597:466b27332893 (btrfs_start_transaction: wait for commits in progress) breaks the transaction start/stop ioctls by making btrfs_start_transaction conditionally wait for the next transaction to start. If an application artificially is holding a transaction open, things deadlock. This workaround maintains a count of open ioctl-initiated transactions in fs_info, and avoids wait_current_trans() if any are currently open (in start_transaction() and btrfs_throttle()). The start transaction ioctl uses a new btrfs_start_ioctl_transaction() that _does_ call wait_current_trans(), effectively pushing the join/wait decision to the outer ioctl-initiated transaction. This more or less neuters btrfs_throttle() when ioctl-initiated transactions are in use, but that seems like a pretty fundamental consequence of wrapping lots of write()'s in a transaction. Btrfs has no way to tell if the application considers a given operation as part of it's transaction. Obviously, if the transaction start/stop ioctls aren't being used, there is no effect on current behavior. Signed-off-by: Sage Weil <sage@newdream.net> --- ctree.h | 1 + ioctl.c | 12 +++++++++++- transaction.c | 18 +++++++++++++----- transaction.h | 2 ++ 4 files changed, 27 insertions(+), 6 deletions(-) Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Improve and cleanup locking done by walk_down_treeChris Mason
While dropping snapshots, walk_down_tree does most of the work of checking reference counts and limiting tree traversal to just the blocks that we are freeing. It dropped and held the allocation mutex in strange and confusing ways, this commit changes it to only hold the mutex while actually freeing a block. The rest of the checks around reference counts should be safe without the lock because we only allow one process in btrfs_drop_snapshot at a time. Other processes dropping reference counts should not drop it to 1 because their tree roots already have an extra ref on the block. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Null terminate strings passed in from userspaceMark Fasheh
The 'char name[BTRFS_PATH_NAME_MAX]' member of struct btrfs_ioctl_vol_args is passed directly to strlen() after being copied from user. I haven't verified this, but in theory a userspace program could pass in an unterminated string and cause a kernel crash as strlen walks off the end of the array. This patch terminates the ->name string in all btrfs ioctl functions which currently use a 'struct btrfs_ioctl_vol_args'. Since the string is now properly terminated, it's length will never be longer than BTRFS_PATH_NAME_MAX so that error check has been removed. By the way, it might be better overall to just have the ioctl pass an unterminated string + length structure but I didn't bother with that since it'd change the kernel/user interface. Signed-off-by: Mark Fasheh <mfasheh@suse.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Fix a few functions that exit without stopping their transactionJosef Bacik
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Implement new dir index formatJosef Bacik
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Fix the defragmention code and the block relocation code for data=orderedChris Mason
Before setting an extent to delalloc, the code needs to wait for pending ordered extents. Also, the relocation code needs to wait for ordered IO before scanning the block group again. This is because the extents are not removed until the IO for the new extents is finished Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Add locking around volume management (device add/remove/balance)Chris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Add btrfs_end_transaction_throttle to force writers to wait for pending commitsChris Mason
The existing throttle mechanism was often not sufficient to prevent new writers from coming in and making a given transaction run forever. This adds an explicit wait at the end of most operations so they will allow the current transaction to close. There is no wait inside file_write, inode updates, or cow filling, all which have different deadlock possibilities. This is a temporary measure until better asynchronous commit support is added. This code leads to stalls as it waits for data=ordered writeback, and it really needs to be fixed. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Replace the big fs_mutex with a collection of other locksChris Mason
Extent alloctions are still protected by a large alloc_mutex. Objectid allocations are covered by a objectid mutex Other btree operations are protected by a lock on individual btree nodes Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Start btree concurrency work.Chris Mason
The allocation trees and the chunk trees are serialized via their own dedicated mutexes. This means allocation location is still not very fine grained. The main FS btree is protected by locks on each block in the btree. Locks are taken top / down, and as processing finishes on a given level of the tree, the lock is released after locking the lower level. The end result of a search is now a path where only the lowest level is locked. Releasing or freeing the path drops any locks held. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25BTRFS_IOC_TRANS_START should be privileguedChristoph Hellwig
As mentioned in the comment next to it btrfs_ioctl_trans_start can do bad damage to filesystems and thus should be limited to privilegued users. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: split out ioctl.cChristoph Hellwig
Split the ioctl handling out of inode.c into a file of it's own. Also fix up checkpatch.pl warnings for the moved code. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>