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path: root/fs/btrfs/relocation.c
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2011-03-28Btrfs: check return value of read_tree_block()Tsutomu Itoh
This patch is checking return value of read_tree_block(), and if it is NULL, error processing. Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-03-17Btrfs: handle errors in btrfs_orphan_cleanupJosef Bacik
If we cannot truncate an inode for some reason we will never delete the orphan item associated with that inode, which means that we will loop forever in btrfs_orphan_cleanup. Instead of doing this just return error so we fail to mount. It sucks, but hey it's better than hanging. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
2011-02-16Btrfs: allow balance to explicitly allocate chunks as it relocatesChris Mason
Btrfs device shrinking and balancing ends up reallocating all the blocks in order to allow COW to move them to new destinations. It is somewhat awkward in terms of ENOSPC because most of the enospc code is built around the idea that some operation on a reference counted tree triggers allocations in the non-reference counted trees. This commit changes the balancing code to deal with enospc by trying to allocate a new chunk. If that allocation succeeds, we go ahead and retry whatever failed due to enospc. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-02-14Btrfs: Fix balance panicYan, Zheng
Mark the cloned backref_node as checked in clone_backref_node() Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-02-01btrfs: fix return value check of btrfs_start_transaction()Tsutomu Itoh
The error check of btrfs_start_transaction() is added, and the mistake of the error check on several places is corrected. Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-01-28btrfs: fix return value check of btrfs_join_transaction()Tsutomu Itoh
The error check of btrfs_join_transaction()/btrfs_join_transaction_nolock() is added, and the mistake of the error check in several places is corrected. For more stable Btrfs, I think that we should reduce BUG_ON(). But, I think that long time is necessary for this. So, I propose this patch as a short-term solution. With this patch: - To more stable Btrfs, the part that should be corrected is clarified. - The panic isn't done by the NULL pointer reference etc. (even if BUG_ON() is increased temporarily) - The error code is returned in the place where the error can be easily returned. As a long-term plan: - BUG_ON() is reduced by using the forced-readonly framework, etc. Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-29Btrfs: Fix variables set but not read (bugs found by gcc 4.6)Andi Kleen
These are all the cases where a variable is set, but not read which are really bugs. - Couple of incorrect error handling fixed. - One incorrect use of a allocation policy - Some other things Still needs more review. Found by gcc 4.6's new warnings. [akpm@linux-foundation.org: fix build. Might have been bitrot] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Chris Mason <chris.mason@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-29Merge branch 'bug-fixes' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs-work Conflicts: fs/btrfs/extent-tree.c Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-28Btrfs: create special free space cache inodeJosef Bacik
In order to save free space cache, we need an inode to hold the data, and we need a special item to point at the right inode for the right block group. So first, create a special item that will point to the right inode, and the number of extent entries we will have and the number of bitmaps we will have. We truncate and pre-allocate space everytime to make sure it's uptodate. This feature will be turned on as soon as you mount with -o space_cache, however it is safe to boot into old kernels, they will just generate the cache the old fashion way. When you boot back into a newer kernel we will notice that we modified and not the cache and automatically discard the cache. Signed-off-by: Josef Bacik <josef@redhat.com>
2010-10-22Btrfs: rework how we reserve metadata bytesJosef Bacik
With multi-threaded writes we were getting ENOSPC early because somebody would come in, start flushing delalloc because they couldn't make their reservation, and in the meantime other threads would come in and use the space that was getting freed up, so when the original thread went to check to see if they had space they didn't and they'd return ENOSPC. So instead if we have some free space but not enough for our reservation, take the reservation and then start doing the flushing. The only time we don't take reservations is when we've already overcommitted our space, that way we don't have people who come late to the party way overcommitting ourselves. This also moves all of the retrying and flushing code into reserve_metdata_bytes so it's all uniform. This keeps my fs_mark test from returning -ENOSPC as soon as it starts and actually lets me fill up the disk. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
2010-06-11Btrfs: Fix null dereference in relocation.cYan, Zheng
Fix a potential null dereference in relocation.c Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Acked-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25Btrfs: Metadata ENOSPC handling for balanceYan, Zheng
This patch adds metadata ENOSPC handling for the balance code. It is consisted by following major changes: 1. Avoid COW tree leave in the phrase of merging tree. 2. Handle interaction with snapshot creation. 3. make the backref cache can live across transactions. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25Btrfs: Pre-allocate space for data relocationYan, Zheng
Pre-allocate space for data relocation. This can detect ENOPSC condition caused by fragmentation of free space. 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>
2010-05-25Btrfs: Introduce contexts for metadata reservationYan, Zheng
Introducing metadata reseravtion contexts has two major advantages. First, it makes metadata reseravtion more traceable. Second, it can reclaim freed space and re-add them to the itself after transaction committed. Besides add btrfs_block_rsv structure and related helper functions, This patch contains following changes: Move code that decides if freed tree block should be pinned into btrfs_free_tree_block(). Make space accounting more accurate, mainly for handling read only block groups. 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>
2010-03-15Btrfs: 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: change how we mount subvolumesJosef Bacik
This work is in preperation for being able to set a different root as the default mounting root. There is currently a problem with how we mount subvolumes. We cannot currently mount a subvolume of a subvolume, you can only mount subvolumes/snapshots of the default subvolume. So say you take a snapshot of the default subvolume and call it snap1, and then take a snapshot of snap1 and call it snap2, so now you have / /snap1 /snap1/snap2 as your available volumes. Currently you can only mount / and /snap1, you cannot mount /snap1/snap2. To fix this problem instead of passing subvolid=<name> you must pass in subvolid=<treeid>, where <treeid> is the tree id that gets spit out via the subvolume listing you get from the subvolume listing patches (btrfs filesystem list). This allows us to mount /, /snap1 and /snap1/snap2 as the root volume. In addition to the above, we also now read the default dir item in the tree root to get the root key that it points to. For now this just points at what has always been the default subvolme, but later on I plan to change it to point at whatever root you want to be the new default root, so you can just set the default mount and not have to mount with -o subvolid=<treeid>. I tested this out with the above scenario and it worked perfectly. Thanks, mount -o subvol operates inside the selected subvolid. For example: mount -o subvol=snap1,subvolid=256 /dev/xxx /mnt /mnt will have the snap1 directory for the subvolume with id 256. mount -o subvol=snap /dev/xxx /mnt /mnt will be the snap directory of whatever the default subvolume is. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-08Btrfs: use RB_ROOT to intialize rb_trees instead of setting rb_node to NULLEric Paris
btrfs inialize rb trees in quite a number of places by settin rb_node = NULL; The problem with this is that 17d9ddc72fb8bba0d4f678 in the linux-next tree adds a new field to that struct which needs to be NULL for the new rbtree library code to work properly. This patch uses RB_ROOT as the intializer so all of the relevant fields will be NULL'd. Without the patch I get a panic. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-02-04Btrfs: remove BUG_ON() due to mounting bad filesystemMiao Xie
Mounting a bad filesystem caused a BUG_ON(). The following is steps to reproduce it. # mkfs.btrfs /dev/sda2 # mount /dev/sda2 /mnt # mkfs.btrfs /dev/sda1 /dev/sda2 (the program says that /dev/sda2 was mounted, and then exits. ) # umount /mnt # mount /dev/sda1 /mnt At the third step, mkfs.btrfs exited in the way of make filesystem. So the initialization of the filesystem didn't finish. So the filesystem was bad, and it caused BUG_ON() when mounting it. But BUG_ON() should be called by the wrong code, not user's operation, so I think it is a bug of btrfs. This patch fixes it. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-01-17Btrfs, fix memory leaks in error pathsJiri Slaby
Stanse found 2 memory leaks in relocate_block_group and __btrfs_map_block. cluster and multi are not freed/assigned on all paths. Fix that. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: linux-btrfs@vger.kernel.org Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-17Btrfs: Add delayed iputYan, Zheng
iput() can trigger new transactions if we are dropping the final reference, so calling it in btrfs_commit_transaction may end up deadlock. This patch adds delayed iput to avoid the issue. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-17Btrfs: Make truncate(2) more ENOSPC friendlyYan, Zheng
truncating and deleting regular files are unbound operations, so it's not good to do them in a single transaction. This patch makes btrfs_truncate and btrfs_delete_inode start a new transaction after all items in a tree leaf are deleted. 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 while replaying logYan, Zheng
We do log replay in a single transaction, so it's not good to do unbound operations. This patch cleans up orphan inodes cleanup after replaying the log. It also avoids doing other unbound operations such as truncating a file during replaying log. These unbound operations are postponed to the orphan inode cleanup stage. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-05Btrfs: fix deadlock on async thread startupChris Mason
The btrfs async worker threads are used for a wide variety of things, including processing bio end_io functions. This means that when the endio threads aren't running, the rest of the FS isn't able to do the final processing required to clear PageWriteback. The endio threads also try to exit as they become idle and start more as the work piles up. The problem is that starting more threads means kthreadd may need to allocate ram, and that allocation may wait until the global number of writeback pages on the system is below a certain limit. The result of that throttling is that end IO threads wait on kthreadd, who is waiting on IO to end, which will never happen. This commit fixes the deadlock by handing off thread startup to a dedicated thread. It also fixes a bug where the on-demand thread creation was creating far too many threads because it didn't take into account threads being started by other procs. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-24Btrfs: relocate file extents in clustersYan, Zheng
The extent relocation code copy file extents one by one when relocating data block group. This is inefficient if file extents are small. This patch makes the relocation code copy file extents in clusters. So we can can make better use of read-ahead. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> 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>
2009-09-11Btrfs: use a cached state for extent state operations during delallocChris Mason
This changes the btrfs code to find delalloc ranges in the extent state tree to use the new state caching code from set/test bit. It reduces one of the biggest causes of rbtree searches in the writeback path. test_range_bit is also modified to take the cached state as a starting point while searching. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-11Btrfs: switch extent_map to a rw lockChris Mason
There are two main users of the extent_map tree. The first is regular file inodes, where it is evenly spread between readers and writers. The second is the chunk allocation tree, which maps blocks from logical addresses to phyiscal ones, and it is 99.99% reads. The mapping tree is a point of lock contention during heavy IO workloads, so this commit switches things to a rw lock. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-08-07Btrfs: fix balancing oops when invalidate_inode_pages2 returns EBUSYYan Zheng
invalidate_inode_pages2_range may return -EBUSY occasionally which results Oops. This patch fixes the issue by moving invalidate_inode_pages2_range into a loop and keeping calling it until the return value is not -EBUSY. The EBUSY return is temporary, and can happen when the btrfs release page function is unable to release a page because the EXTENT_LOCK bit is set. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-22Btrfs: fix locking issue in btrfs_find_next_keyYan Zheng
When walking up the tree, btrfs_find_next_key assumes the upper level tree block is properly locked. This isn't always true even path->keep_locks is 1. This is because btrfs_find_next_key may advance path->slots[] several times instead of only once. When 'path->slots[level] >= btrfs_header_nritems(path->nodes[level])' is found, we can't guarantee the original value of 'path->slots[level]' is 'btrfs_header_nritems(path->nodes[level]) - 1'. If it's not, the tree block at 'level + 1' isn't locked. This patch fixes the issue by explicitly checking the locking state, re-searching the tree if it's not locked. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-02Btrfs: update backrefs while dropping snapshotYan Zheng
The new backref format has restriction on type of backref item. If a tree block isn't referenced by its owner tree, full backrefs must be used for the pointers in it. When a tree block loses its owner tree's reference, backrefs for the pointers in it should be updated to full backrefs. Current btrfs_drop_snapshot misses the code that updates backrefs, so it's unsafe for general use. This patch adds backrefs update code to btrfs_drop_snapshot. It isn't a problem in the restricted form btrfs_drop_snapshot is used today, but for general snapshot deletion this update is required. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> 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>