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2010-07-19Btrfs: fix checks in BTRFS_IOC_CLONE_RANGEDan Rosenberg
1. The BTRFS_IOC_CLONE and BTRFS_IOC_CLONE_RANGE ioctls should check whether the donor file is append-only before writing to it. 2. The BTRFS_IOC_CLONE_RANGE ioctl appears to have an integer overflow that allows a user to specify an out-of-bounds range to copy from the source file (if off + len wraps around). I haven't been able to successfully exploit this, but I'd imagine that a clever attacker could use this to read things he shouldn't. Even if it's not exploitable, it couldn't hurt to be safe. Signed-off-by: Dan Rosenberg <dan.j.rosenberg@gmail.com> cc: stable@kernel.org Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-07-19Btrfs: fix CLONE ioctl destination file size expansion to block boundarySage Weil
The CLONE and CLONE_RANGE ioctls round up the range of extents being cloned to the block size when the range to clone extends to the end of file (this is always the case with CLONE). It was then using that offset when extending the destination file's i_size. Fix this by not setting i_size beyond the originally requested ending offset. This bug was introduced by a22285a6 (2.6.35-rc1). Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-06-11Btrfs: btrfs_lookup_dir_item() can return ERR_PTRDan Carpenter
btrfs_lookup_dir_item() can return either ERR_PTRs or null. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-06-11Btrfs: unwind after btrfs_start_transaction() errorsDan Carpenter
This was added by a22285a6a3: "Btrfs: Integrate metadata reservation with start_transaction". If we goto out here then we skip all the unwinding and there are locks still held etc. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25Btrfs: Metadata reservation for orphan inodesYan, Zheng
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>
2010-05-25Btrfs: Introduce global metadata reservationYan, Zheng
Reserve metadata space for extent tree, checksum tree and root tree Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25Btrfs: Update metadata reservation for delayed allocationYan, Zheng
Introduce metadata reservation context for delayed allocation and update various related functions. This patch also introduces EXTENT_FIRST_DELALLOC control bit for set/clear_extent_bit. It tells set/clear_bit_hook whether they are processing the first extent_state with EXTENT_DELALLOC bit set. This change is important if set/clear_extent_bit involves multiple extent_state. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25Btrfs: Integrate metadata reservation with start_transactionYan, Zheng
Besides simplify the code, this change makes sure all metadata reservation for normal metadata operations are released after committing transaction. Changes since V1: Add code that check if unlink and rmdir will free space. Add ENOSPC handling for clone ioctl. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: Btrfs: check for read permission on src file in the clone ioctl
2010-05-15Btrfs: check for read permission on src file in the clone ioctlDan Rosenberg
The existing code would have allowed you to clone a file that was only open for writing Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-04-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: Btrfs: add check for changed leaves in setup_leaf_for_split Btrfs: create snapshot references in same commit as snapshot Btrfs: fix small race with delalloc flushing waitqueue's Btrfs: use add_to_page_cache_lru, use __page_cache_alloc Btrfs: fix chunk allocate size calculation Btrfs: kill max_extent mount option Btrfs: fail to mount if we have problems reading the block groups Btrfs: check btrfs_get_extent return for IS_ERR() Btrfs: handle kmalloc() failure in inode lookup ioctl Btrfs: dereferencing freed memory Btrfs: Simplify num_stripes's calculation logical for __btrfs_alloc_chunk() Btrfs: Add error handle for btrfs_search_slot() in btrfs_read_chunk_tree() Btrfs: Remove unnecessary finish_wait() in wait_current_trans() Btrfs: add NULL check for do_walk_down() Btrfs: remove duplicate include in ioctl.c Fix trivial conflict in fs/btrfs/compression.c due to slab.h include cleanups.
2010-03-30Btrfs: check btrfs_get_extent return for IS_ERR()Dan Carpenter
btrfs_get_extent() never returns NULL, only a valid pointer or ERR_PTR() Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-30Btrfs: handle kmalloc() failure in inode lookup ioctlDan Carpenter
Return -ENOMEM if kmalloc() fails. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-30Btrfs: dereferencing freed memoryDan Carpenter
The original code dereferenced range on the next line. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-30Btrfs: remove duplicate include in ioctl.cAndrea Gelmini
fs/btrfs/ioctl.c: ctree.h is included more than once. Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-18Btrfs: fix the inode ref searches done by btrfs_search_path_in_treeChris Mason
This is used by the inode lookup ioctl to follow all the backrefs up to the subvol root. But the search being done would sometimes land one past the last item in the leaf instead of finding the backref. This changes the search to look for the highest possible backref and hop back one item. It also fixes a leaked path on failure to find the root. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-18Btrfs: allow treeid==0 in the inode lookup ioctlChris Mason
When a root id of 0 is sent to the inode lookup ioctl, it will use the root of the file we're ioctling and pass the root id back to userland along with the results. This allows userland to do searches based on that root later on. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-18Btrfs: return keys for large items to the search ioctlChris Mason
The search ioctl was skipping large items entirely (ones that are too big for the results buffer). This changes things to at least copy the item header so that we can send information about the item back to userland. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-18Btrfs: fix key checks and advance in the search ioctlChris Mason
The search ioctl was working well for finding tree roots, but using it for generic searches requires a few changes to how the keys are advanced. This treats the search control min fields for objectid, type and offset more like a key, where we drop the offset to zero once we bump the type, etc. The downside of this is that we are changing the min_type and min_offset fields during the search, and so the ioctl caller needs extra checks to make sure the keys in the result are the ones it wanted. This also changes key_in_sk to use btrfs_comp_cpu_keys, just to make things more readable. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-16Btrfs: buffer results in the space_info ioctlChris Mason
The space_info ioctl was using copy_to_user inside rcu_read_lock. This commit changes things to copy into a buffer first and then dump the result down to userland. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-16Btrfs: fix search_ioctl key advanceSage Weil
key->type is u8, not u64. fs/btrfs/ioctl.c: In function 'copy_to_sk': fs/btrfs/ioctl.c:1024: warning: comparison is always true due to limited range of data type Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15btrfs: use memparseAkinobu Mita
Use memparse() instead of its own private implementation. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: linux-btrfs@vger.kernel.org Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15Btrfs: add a "df" ioctl for btrfsJosef Bacik
df is a very loaded question in btrfs. This gives us a way to get the per-space usage information so we can tell exactly what is in use where. This will help us figure out ENOSPC problems, and help users better understand where their disk space is going. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15Btrfs: cache the extent state everywhere we possibly can V2Josef Bacik
This patch just goes through and fixes everybody that does lock_extent() blah unlock_extent() to use lock_extent_bits() blah unlock_extent_cached() and pass around a extent_state so we only have to do the searches once per function. This gives me about a 3 mb/s boots on my random write test. I have not converted some things, like the relocation and ioctl's, since they aren't heavily used and the relocation stuff is in the middle of being re-written. I also changed the clear_extent_bit() to only unset the cached state if we are clearing EXTENT_LOCKED and related stuff, so we can do things like this lock_extent_bits() clear delalloc bits unlock_extent_cached() without losing our cached state. I tested this thoroughly and turned on LEAK_DEBUG to make sure we weren't leaking extent states, everything worked out fine. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15Btrfs: add new defrag-range ioctl.Chris Mason
The btrfs defrag ioctl was limited to doing the entire file. This commit adds a new interface that can defrag a specific range inside the file. It can also force compression on the file, allowing you to selectively compress individual files after they were created, even when mount -o compress isn't turned on. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15Btrfs: be more selective in the defrag ioctlChris Mason
The btrfs defrag ioctl had some bugs around delalloc accounting, and it wasn't properly skipping pages that were not in the mapping. It wasn't properly clearing the page checked flag, which could make the writeback code ignore the page forever while pinning it as dirty. This commit fixes those problems and makes defrag a little smarter. It skips holes and it doesn't waste time defragging large extents. If a tiny extent comes before a very large extent, it will defrag both of them to make sure the tiny extent ends up next to something big. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15Btrfs: add ioctl and incompat flag to set the default mount subvolJosef Bacik
This patch needs to go along with my previous patch. This lets us set the default dir item's location to whatever root we want to use as our default mounting subvol. With this we don't have to use mount -o subvol=<tree id> anymore to mount a different subvol, we can just set the new one and it will just magically work. I've done some moderate testing with this, mostly just switching the default mount around, mounting subvols and the default mount at the same time and such, everything seems to work. Thanks, Older kernels would generally be able to still mount the filesystem with the default subvolume set, but it would result in a different volume being mounted, which could be an even more unpleasant suprise for users. So if you set your default subvolume, you can't go back to older kernels. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15Btrfs: add search and inode lookup ioctlsChris Mason
The search ioctl is a generic tool for doing btree searches from userland applications. The first user of the search ioctl is a subvolume listing feature, but we'll also use it to find new files in a subvolume. The search ioctl allows you to specify min and max keys to search for, along with min and max transid. It returns the items along with a header that includes the item key. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15Btrfs: add a function to lookup a directory path by following backrefsTARUISI Hiroaki
This will be used by the inode lookup ioctl. Signed-off-by: TARUISI Hiroaki <taruishi.hiroak@jp.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-17Btrfs: Fix per root used space accountingYan, Zheng
The bytes_used field in root item was originally planned to trace the amount of used data and tree blocks. But it never worked right since we can't trace freeing of data accurately. This patch changes it to only trace the amount of tree blocks. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-17Btrfs: Avoid orphan inodes cleanup during committing transactionYan, Zheng
btrfs_lookup_dentry may trigger orphan cleanup, so it's not good to call it while committing a transaction. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-15Btrfs: Rewrite btrfs_drop_extentsYan, Zheng
Rewrite btrfs_drop_extents by using btrfs_duplicate_item, so we can avoid calling lock_extent within transaction. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-09Btrfs: fix file clone ioctl for bookend extentsChris Mason
The file clone ioctl was incorrectly taking the offset into the extent on disk into account when calculating the length of the cloned extent. The length never changes based on the offset into the physical extent. Test case: fallocate -l 1g image mke2fs image bcp image image2 e2fsck -f image2 (errors on image2) The math bug ends up wrapping the length of the extent, and things go wrong from there. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-09Btrfs: remove negative dentry when deleting subvolumneYan, Zheng
The use of btrfs_dentry_delete is removing dentries from the dcache when deleting subvolumne. btrfs_dentry_delete ignores negative dentries. This is incorrect since if we don't remove the negative dentry, its parent dentry can't be removed. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-29Btrfs: fix error cases for ioctl transactionsSage Weil
Fix leak of vfsmount write reference and open_ioctl_trans reference on ENOMEM. Clean up the error paths while we're at it. Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-28Btrfs: proper -ENOSPC handlingJosef Bacik
At the start of a transaction we do a btrfs_reserve_metadata_space() and specify how many items we plan on modifying. Then once we've done our modifications and such, just call btrfs_unreserve_metadata_space() for the same number of items we reserved. For keeping track of metadata needed for data I've had to add an extent_io op for when we merge extents. This lets us track space properly when we are doing sequential writes, so we don't end up reserving way more metadata space than what we need. The only place where the metadata space accounting is not done is in the relocation code. This is because Yan is going to be reworking that code in the near future, so running btrfs-vol -b could still possibly result in a ENOSPC related panic. This patch also turns off the metadata_ratio stuff in order to allow users to more efficiently use their disk space. This patch makes it so we track how much metadata we need for an inode's delayed allocation extents by tracking how many extents are currently waiting for allocation. It introduces two new callbacks for the extent_io tree's, merge_extent_hook and split_extent_hook. These help us keep track of when we merge delalloc extents together and split them up. Reservations are handled prior to any actually dirty'ing occurs, and then we unreserve after we dirty. btrfs_unreserve_metadata_for_delalloc() will make the appropriate unreservations as needed based on the number of reservations we currently have and the number of extents we currently have. Doing the reservation outside of doing any of the actual dirty'ing lets us do things like filemap_flush() the inode to try and force delalloc to happen, or as a last resort actually start allocation on all delalloc inodes in the fs. This has survived dbench, fs_mark and an fsx torture test. Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-21Btrfs: fix arithmetic error in clone ioctlSage Weil
Fix an arithmetic error that was breaking extents cloned via the clone ioctl starting in the second half of a file. Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-21Btrfs: add snapshot/subvolume destroy ioctlYan, Zheng
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>
2009-09-21Btrfs: change how subvolumes are organizedYan, Zheng
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>
2009-09-11Merge branch 'master' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
2009-09-11Btrfs: Fix extent replacment raceChris Mason
Data COW means that whenever we write to a file, we replace any old extent pointers with new ones. There was a window where a readpage might find the old extent pointers on disk and cache them in the extent_map tree in ram in the middle of a given write replacing them. Even though both the readpage and the write had their respective bytes in the file locked, the extent readpage inserts may cover more bytes than it had locked down. This commit closes the race by keeping the new extent pinned in the extent map tree until after the on-disk btree is properly setup with the new extent pointers. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-12headers: smp_lock.h reduxAlexey Dobriyan
* Remove smp_lock.h from files which don't need it (including some headers!) * Add smp_lock.h to files which do need it * Make smp_lock.h include conditional in hardirq.h It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT This will make hardirq.h inclusion cheaper for every PREEMPT=n config (which includes allmodconfig/allyesconfig, BTW) Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-02Btrfs: fix the file clone ioctl for preallocated extentsChris Mason
2009-06-11Btrfs: fix oops when btrfs_inherit_iflags called with a NULL dirChris Mason
This happens during subvol creation. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: implement FS_IOC_GETFLAGS/SETFLAGS/GETVERSIONChristoph Hellwig
Add support for the standard attributes set via chattr and read via lsattr. Currently we store the attributes in the flags value in the btrfs inode, but I wonder whether we should split it into two so that we don't have to keep converting between the two formats. Remove the btrfs_clear_flag/btrfs_set_flag/btrfs_test_flag macros as they were confusing the existing code and got in the way of the new additions. Also add the FS_IOC_GETVERSION ioctl for getting i_generation as it's trivial. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE)Yan Zheng
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>
2009-05-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: Btrfs: Spelling fix in btrfs_lookup_first_block_group comments Btrfs: make show_options result match actual option names Btrfs: remove outdated comment in btrfs_ioctl_resize() Btrfs: remove some WARN_ONs in the IO failure path Btrfs: Don't loop forever on metadata IO failures Btrfs: init inode ordered_data_close flag properly
2009-05-14Btrfs: remove outdated comment in btrfs_ioctl_resize()Li Hong
In Li Zefan's commit dae7b665cf6d6e6e733f1c9c16cf55547dd37e33, a combination call of kmalloc() and copy_from_user() is replaced by memdup_user(). So btrfs_ioctl_resize() doesn't use GFP_NOFS any more. Signed-off-by: Li Hong <lihong.hi@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: Btrfs: look for acls during btrfs_read_locked_inode Btrfs: fix acl caching Btrfs: Fix a bunch of printk() warnings. Btrfs: Fix a trivial warning using max() of u64 vs ULL. Btrfs: remove unused btrfs_bit_radix slab Btrfs: ratelimit IO error printks Btrfs: remove #if 0 code Btrfs: When shrinking, only update disk size on success Btrfs: fix deadlocks and stalls on dead root removal Btrfs: fix fallocate deadlock on inode extent lock Btrfs: kill btrfs_cache_create Btrfs: don't export symbols Btrfs: simplify makefile Btrfs: try to keep a healthy ratio of metadata vs data block groups