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path: root/fs/btrfs/root-tree.c
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* Btrfs: avoid BUG when dropping root and reference in same transactionSage Weil2010-06-111-3/+0
| | | | | | | | | | | | | | | | | | | | If btrfs_ioctl_snap_destroy() deletes a snapshot but finishes with end_transaction(), the cleaner kthread may come in and drop the root in the same transaction. If that's the case, the root's refs still == 1 in the tree when btrfs_del_root() deletes the item, because commit_fs_roots() hasn't updated it yet (that happens during the commit). This wasn't a problem before only because btrfs_ioctl_snap_destroy() would commit the transaction before dropping the dentry reference, so the dead root wouldn't get queued up until after the fs root item was updated in the btree. Since it is not an error to drop the root reference and the root in the same transaction, just drop the BUG_ON() in btrfs_del_root(). Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Metadata reservation for orphan inodesYan, Zheng2010-05-251-3/+20
| | | | | | | reserve metadata space for handling orphan inodes Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: skip btrfs_release_path in btrfs_update_root and btrfs_del_rootLi Dongyang2009-11-111-2/+0
| | | | | | | | We don't need to call btrfs_release_path because btrfs_free_path will do that for us. Signed-off-by: Li Dongyang <Jerry87905@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: add snapshot/subvolume destroy ioctlYan, Zheng2009-09-211-5/+64
| | | | | | | | This patch adds snapshot/subvolume destroy ioctl. A subvolume that isn't being used and doesn't contains links to other subvolumes can be destroyed. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: change how subvolumes are organizedYan, Zheng2009-09-211-18/+51
| | | | | | | | | | | | | | | | | | | | | btrfs allows subvolumes and snapshots anywhere in the directory tree. If we snapshot a subvolume that contains a link to other subvolume called subvolA, subvolA can be accessed through both the original subvolume and the snapshot. This is similar to creating hard link to directory, and has the very similar problems. The aim of this patch is enforcing there is only one access point to each subvolume. Only the first directory entry (the one added when the subvolume/snapshot was created) is treated as valid access point. The first directory entry is distinguished by checking root forward reference. If the corresponding root forward reference is missing, we know the entry is not the first one. This patch also adds snapshot/subvolume rename support, the code allows rename subvolume link across subvolumes. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE)Yan Zheng2009-06-101-6/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. When a tree block in subvolume tree is cow'd, the reference counts of all extents it points to are increased by one. At transaction commit time, the old root of the subvolume is recorded in a "dead root" data structure, and the btree it points to is later walked, dropping reference counts and freeing any blocks where the reference count goes to 0. The increments done during cow and decrements done after commit cancel out, and the walk is a very expensive way to go about freeing the blocks that are no longer referenced by the new btree root. This commit reduces the transaction overhead by avoiding the need for dead root records. When a non-shared tree block is cow'd, we free the old block at once, and the new block inherits old block's references. When a tree block with reference count > 1 is cow'd, we increase the reference counts of all extents the new block points to by one, and decrease the old block's reference count by one. This dead tree avoidance code removes the need to modify the reference counts of lower level extents when a non-shared tree block is cow'd. But we still need to update back ref for all pointers in the block. This is because the location of the block is recorded in the back ref item. We can solve this by introducing a new type of back ref. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference on a given block. This commit adds per subvolume red-black tree to keep trace of cached inodes. The red-black tree helps the balancing code to find cached inodes whose inode numbers within a given range. This commit improves the balancing code by introducing several data structures to keep the state of balancing. The most important one is the back ref cache. It caches how the upper level tree blocks are referenced. This greatly reduce the overhead of checking back ref. The improved balancing code scales significantly better with a large number of snapshots. This is a very large commit and was written in a number of pieces. But, they depend heavily on the disk format change and were squashed together to make sure git bisect didn't end up in a bad state wrt space balancing or the format change. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Fix checkpatch.pl warningsChris Mason2009-01-051-10/+7
| | | | | | | 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>
* Btrfs: make things static and include the right headersChristoph Hellwig2008-12-021-0/+2
| | | | | | | | 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>
* Btrfs: prevent loops in the directory tree when creating snapshotsChris Mason2008-11-171-0/+16
| | | | | | | | | | | | | | | 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>
* Btrfs: Add backrefs and forward refs for subvols and snapshotsChris Mason2008-11-171-1/+75
| | | | | | | | | | | | | 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>
* Btrfs: add and improve commentsChris Mason2008-09-291-2/+19
| | | | | | | | | | | This improves the comments at the top of many functions. It didn't dive into the guts of functions because I was trying to avoid merging problems with the new allocator and back reference work. extent-tree.c and volumes.c were both skipped, and there is definitely more work todo in cleaning and commenting the code. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: update space balancing codeZheng Yan2008-09-261-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch updates the space balancing code to utilize the new backref format. Before, btrfs-vol -b would break any COW links on data blocks or metadata. This was slow and caused the amount of space used to explode if a large number of snapshots were present. The new code can keeps the sharing of all data extents and most of the tree blocks. To maintain the sharing of data extents, the space balance code uses a seperate inode hold data extent pointers, then updates the references to point to the new location. To maintain the sharing of tree blocks, the space balance code uses reloc trees to relocate tree blocks in reference counted roots. There is one reloc tree for each subvol, and all reloc trees share same root key objectid. Reloc trees are snapshots of the latest committed roots of subvols (root->commit_root). To relocate a tree block referenced by a subvol, there are two steps. COW the block through subvol's reloc tree, then update block pointer in the subvol to point to the new block. Since all reloc trees share same root key objectid, doing special handing for tree blocks owned by them is easy. Once a tree block has been COWed in one reloc tree, we can use the resulting new block directly when the same block is required to COW again through other reloc trees. In this way, relocated tree blocks are shared between reloc trees, so they are also shared between subvols. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Add a write ahead tree log to optimize synchronous operationsChris Mason2008-09-251-2/+3
| | | | | | | | | | | File syncs and directory syncs are optimized by copying their items into a special (copy-on-write) log tree. There is one log tree per subvolume and the btrfs super block points to a tree of log tree roots. After a crash, items are copied out of the log tree and back into the subvolume. See tree-log.c for all the details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Various small fixes.Yan Zheng2008-09-251-2/+1
| | | | | | | | This trivial patch contains two locking fixes and a off by one fix. --- Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Fix deadlock while searching for dead roots on mountChris Mason2008-09-251-1/+9
| | | | | | | | | | btrfs_find_dead_roots called btrfs_read_fs_root_no_radix, which means we end up calling btrfs_search_slot with a path already held. The fix is to remember the key inside btrfs_find_dead_roots and drop the path. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Properly find the root for snapshotted blocks during chunk relocationChris Mason2008-09-251-1/+45
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Change st_blocksize to 4kChris Mason2008-09-251-1/+8
| | | | | | | Some programs (python) do rwm cycles at the granularity returned by stat. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Support for online FS resize (grow and shrink)Chris Mason2008-09-251-0/+5
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Create extent_buffer interface for large blocksizesChris Mason2008-09-251-24/+27
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Find and remove dead roots the first time a root is loaded.Chris Mason2007-09-111-3/+13
| | | | | | | | | | | | | | Dead roots are trees left over after a crash, and they were either in the process of being removed or were waiting to be removed when the box crashed. Before, a search of the entire tree of root pointers was done on mount looking for dead roots. Now, the search is done the first time we load a root. This makes mount faster when there are a large number of snapshots, and it enables the block accounting code to properly update the block counts on the latest root as old versions of the root are reaped after a crash. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Some code cleanupsAneesh2007-07-111-2/+2
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: trivial include fixupsZach Brown2007-07-111-1/+0
| | | | | | | | | | | Almost none of the files including module.h need to do so, remove them. Include sched.h in extent-tree.c to silence a warning about cond_resched() being undeclared. Signed-off-by: Zach Brown <zach.brown@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Documentation updateChris Mason2007-06-221-2/+0
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Add the ability to find and remove dead roots after a crash.Chris Mason2007-06-221-9/+66
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Audit callers and return codes to make sure -ENOSPC gets up the stackChris Mason2007-06-221-1/+0
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* btrfs: Code cleanupAneesh2007-06-131-3/+0
| | | | | | | | | | | Attaching below is some of the code cleanups that i came across while reading the code. a) alloc_path already calls init_path. b) Mention that btrfs_inode is the in memory copy.Ext4 have ext4_inode_info as the in memory copy ext4_inode as the disk copy Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: add GPLv2Chris Mason2007-06-121-0/+18
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: printk fixesChris Mason2007-06-121-1/+1
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: 64 bit div fixesChris Mason2007-06-121-1/+1
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: early fsync supportChris Mason2007-04-191-1/+0
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: snapshot progressChris Mason2007-04-101-1/+15
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: dynamic allocation of path structChris Mason2007-04-021-19/+28
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: corruption hunt continuesChris Mason2007-03-301-3/+4
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* btrfs_create, btrfs_write_super, btrfs_sync_fsChris Mason2007-03-231-0/+1
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Mountable btrfs, with readdirChris Mason2007-03-221-2/+2
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: initial move to kernel module landChris Mason2007-03-211-4/+1
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: transaction handles everywhereChris Mason2007-03-161-10/+13
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Use a chunk of the key flags to record the item type.Chris Mason2007-03-151-1/+1
| | | | | | | | Add (untested and simple) directory item code Fix comp_keys to use the new key ordering Add btrfs_insert_empty_item Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: variable block size supportChris Mason2007-03-141-2/+2
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Change the super to point to a tree of trees to enable persistent ↵Chris Mason2007-03-131-0/+88
snapshots Signed-off-by: Chris Mason <chris.mason@oracle.com>
generated by cgit v1.1 at 2024-11-16 19:05:16 +0000