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2009-04-01Merge 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: try to free metadata pages when we free btree blocks Btrfs: add extra flushing for renames and truncates Btrfs: make sure btrfs_update_delayed_ref doesn't increase ref_mod Btrfs: optimize fsyncs on old files Btrfs: tree logging unlink/rename fixes Btrfs: Make sure i_nlink doesn't hit zero too soon during log replay Btrfs: limit balancing work while flushing delayed refs Btrfs: readahead checksums during btrfs_finish_ordered_io Btrfs: leave btree locks spinning more often Btrfs: Only let very young transactions grow during commit Btrfs: Check for a blocking lock before taking the spin Btrfs: reduce stack in cow_file_range Btrfs: reduce stalls during transaction commit Btrfs: process the delayed reference queue in clusters Btrfs: try to cleanup delayed refs while freeing extents Btrfs: reduce stack usage in some crucial tree balancing functions Btrfs: do extent allocation and reference count updates in the background Btrfs: don't preallocate metadata blocks during btrfs_search_slot
2009-04-01fs: fix page_mkwrite error cases in core code and btrfsNick Piggin
page_mkwrite is called with neither the page lock nor the ptl held. This means a page can be concurrently truncated or invalidated out from underneath it. Callers are supposed to prevent truncate races themselves, however previously the only thing they can do in case they hit one is to raise a SIGBUS. A sigbus is wrong for the case that the page has been invalidated or truncated within i_size (eg. hole punched). Callers may also have to perform memory allocations in this path, where again, SIGBUS would be wrong. The previous patch ("mm: page_mkwrite change prototype to match fault") made it possible to properly specify errors. Convert the generic buffer.c code and btrfs to return sane error values (in the case of page removed from pagecache, VM_FAULT_NOPAGE will cause the fault handler to exit without doing anything, and the fault will be retried properly). This fixes core code, and converts btrfs as a template/example. All other filesystems defining their own page_mkwrite should be fixed in a similar manner. Acked-by: Chris Mason <chris.mason@oracle.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01mm: page_mkwrite change prototype to match faultNick Piggin
Change the page_mkwrite prototype to take a struct vm_fault, and return VM_FAULT_xxx flags. There should be no functional change. This makes it possible to return much more detailed error information to the VM (and also can provide more information eg. virtual_address to the driver, which might be important in some special cases). This is required for a subsequent fix. And will also make it easier to merge page_mkwrite() with fault() in future. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Chris Mason <chris.mason@oracle.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Artem Bityutskiy <dedekind@infradead.org> Cc: Felix Blyakher <felixb@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-31Btrfs: try to free metadata pages when we free btree blocksChris Mason
COW means we cycle though blocks fairly quickly, and once we free an extent on disk, it doesn't make much sense to keep the pages around. This commit tries to immediately free the page when we free the extent, which lowers our memory footprint significantly. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-31Btrfs: add extra flushing for renames and truncatesChris Mason
Renames and truncates are both common ways to replace old data with new data. The filesystem can make an effort to make sure the new data is on disk before actually replacing the old data. This is especially important for rename, which many application use as though it were atomic for both the data and the metadata involved. The current btrfs code will happily replace a file that is fully on disk with one that was just created and still has pending IO. If we crash after transaction commit but before the IO is done, we'll end up replacing a good file with a zero length file. The solution used here is to create a list of inodes that need special ordering and force them to disk before the commit is done. This is similar to the ext3 style data=ordering, except it is only done on selected files. Btrfs is able to get away with this because it does not wait on commits very often, even for fsync (which use a sub-commit). For renames, we order the file when it wasn't already on disk and when it is replacing an existing file. Larger files are sent to filemap_flush right away (before the transaction handle is opened). For truncates, we order if the file goes from non-zero size down to zero size. This is a little different, because at the time of the truncate the file has no dirty bytes to order. But, we flag the inode so that it is added to the ordered list on close (via release method). We also immediately add it to the ordered list of the current transaction so that we can try to flush down any writes the application sneaks in before commit. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-26btrfs: get rid of current_is_pdflush() in btrfs_btree_balance_dirtyJens Axboe
Chris says it's safe to kill. Acked-by: Chris Mason <chris.mason@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-03-25Btrfs: make sure btrfs_update_delayed_ref doesn't increase ref_modChris Mason
btrfs_update_delayed_ref is optimized to add and remove different references in one pass through the delayed ref tree. It is a zero sum on the total number of refs on a given extent. But, the code was recording an extra ref in the head node. This never made it down to the disk but was used when deciding if it was safe to free the extent while dropping snapshots. The fix used here is to make sure the ref_mod count is unchanged on the head ref when btrfs_update_delayed_ref is called. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: optimize fsyncs on old filesChris Mason
The fsync log has code to make sure all of the parents of a file are in the log along with the file. It uses a minimal log of the parent directory inodes, just enough to get the parent directory on disk. If the transaction that originally created a file is fully on disk, and the file hasn't been renamed or linked into other directories, we can safely skip the parent directory walk. We know the file is on disk somewhere and we can go ahead and just log that single file. This is more important now because unrelated unlinks in the parent directory might make us force a commit if we try to log the parent. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: tree logging unlink/rename fixesChris Mason
The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: Make sure i_nlink doesn't hit zero too soon during log replayChris Mason
During log replay, inodes are copied from the log to the main filesystem btrees. Sometimes they have a zero link count in the log but they actually gain links during the replay or have some in the main btree. This patch updates the link count to be at least one after copying the inode out of the log. This makes sure the inode is deleted during an iput while the rest of the replay code is still working on it. The log replay has fixup code to make sure that link counts are correct at the end of the replay, so we could use any non-zero number here and it would work fine. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: limit balancing work while flushing delayed refsChris Mason
The delayed reference mechanism is responsible for all updates to the extent allocation trees, including those updates created while processing the delayed references. This commit tries to limit the amount of work that gets created during the final run of delayed refs before a commit. It avoids cowing new blocks unless it is required to finish the commit, and so it avoids new allocations that were not really required. The goal is to avoid infinite loops where we are always making more work on the final run of delayed refs. Over the long term we'll make a special log for the last delayed ref updates as well. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: readahead checksums during btrfs_finish_ordered_ioChris Mason
This reads in blocks in the checksum btree before starting the transaction in btrfs_finish_ordered_io. It makes it much more likely we'll be able to do operations inside the transaction without needing any btree reads, which limits transaction latencies overall. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: leave btree locks spinning more oftenChris Mason
btrfs_mark_buffer dirty would set dirty bits in the extent_io tree for the buffers it was dirtying. This may require a kmalloc and it was not atomic. So, anyone who called btrfs_mark_buffer_dirty had to set any btree locks they were holding to blocking first. This commit changes dirty tracking for extent buffers to just use a flag in the extent buffer. Now that we have one and only one extent buffer per page, this can be safely done without losing dirty bits along the way. This also introduces a path->leave_spinning flag that callers of btrfs_search_slot can use to indicate they will properly deal with a path returned where all the locks are spinning instead of blocking. Many of the btree search callers now expect spinning paths, resulting in better btree concurrency overall. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: Only let very young transactions grow during commitChris Mason
Commits are fairly expensive, and so btrfs has code to sit around for a while during the commit and let new writers come in. But, while we're sitting there, new delayed refs might be added, and those can be expensive to process as well. Unless the transaction is very very young, it makes sense to go ahead and let the commit finish without hanging around. The commit grow loop isn't as important as it used to be, the fsync logging code handles most performance critical syncs now. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: Check for a blocking lock before taking the spinChris Mason
This reduces contention on the extent buffer spin locks by testing for a blocking lock before trying to take the spinlock. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: reduce stack in cow_file_rangeChris Mason
The fs/btrfs/inode.c code to run delayed allocation during writout needed some stack usage optimization. This is the first pass, it does the check for compression earlier on, which allows us to do the common (no compression) case higher up in the call chain. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: reduce stalls during transaction commitChris Mason
To avoid deadlocks and reduce latencies during some critical operations, some transaction writers are allowed to jump into the running transaction and make it run a little longer, while others sit around and wait for the commit to finish. This is a bit unfair, especially when the callers that jump in do a bunch of IO that makes all the others procs on the box wait. This commit reduces the stalls this produces by pre-reading file extent pointers during btrfs_finish_ordered_io before the transaction is joined. It also tunes the drop_snapshot code to politely wait for transactions that have started writing out their delayed refs to finish. This avoids new delayed refs being flooded into the queue while we're trying to close off the transaction. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: process the delayed reference queue in clustersChris Mason
The delayed reference queue maintains pending operations that need to be done to the extent allocation tree. These are processed by finding records in the tree that are not currently being processed one at a time. This is slow because it uses lots of time searching through the rbtree and because it creates lock contention on the extent allocation tree when lots of different procs are running delayed refs at the same time. This commit changes things to grab a cluster of refs for processing, using a cursor into the rbtree as the starting point of the next search. This way we walk smoothly through the rbtree. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: try to cleanup delayed refs while freeing extentsChris Mason
When extents are freed, it is likely that we've removed the last delayed reference update for the extent. This checks the delayed ref tree when things are freed, and if no ref updates area left it immediately processes the delayed ref. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: reduce stack usage in some crucial tree balancing functionsChris Mason
Many of the tree balancing functions follow the same pattern. 1) cow a block 2) do something to the result This commit breaks them up into two functions so the variables and code required for part two don't suck down stack during part one. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: do extent allocation and reference count updates in the backgroundChris Mason
The extent allocation tree maintains a reference count and full back reference information for every extent allocated in the filesystem. For subvolume and snapshot trees, every time a block goes through COW, the new copy of the block adds a reference on every block it points to. If a btree node points to 150 leaves, then the COW code needs to go and add backrefs on 150 different extents, which might be spread all over the extent allocation tree. These updates currently happen during btrfs_cow_block, and most COWs happen during btrfs_search_slot. btrfs_search_slot has locks held on both the parent and the node we are COWing, and so we really want to avoid IO during the COW if we can. This commit adds an rbtree of pending reference count updates and extent allocations. The tree is ordered by byte number of the extent and byte number of the parent for the back reference. The tree allows us to: 1) Modify back references in something close to disk order, reducing seeks 2) Significantly reduce the number of modifications made as block pointers are balanced around 3) Do all of the extent insertion and back reference modifications outside of the performance critical btrfs_search_slot code. #3 has the added benefit of greatly reducing the btrfs stack footprint. The extent allocation tree modifications are done without the deep (and somewhat recursive) call chains used in the past. These delayed back reference updates must be done before the transaction commits, and so the rbtree is tied to the transaction. Throttling is implemented to help keep the queue of backrefs at a reasonable size. Since there was a similar mechanism in place for the extent tree extents, that is removed and replaced by the delayed reference tree. Yan Zheng <yan.zheng@oracle.com> helped review and fixup this code. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: don't preallocate metadata blocks during btrfs_search_slotChris Mason
In order to avoid doing expensive extent management with tree locks held, btrfs_search_slot will preallocate tree blocks for use by COW without any tree locks held. A later commit moves all of the extent allocation work for COW into a delayed update mechanism, and this preallocation will no longer be required. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-10Btrfs: Clear space_info full when adding new devicesChris Mason
The full flag on the space info structs tells the allocator not to try and allocate more chunks because the devices in the FS are fully allocated. When more devices are added, we need to clear the full flag so the allocator knows it has more space available. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-10Btrfs: Fix locking around adding new space_infoChris Mason
Storage allocated to different raid levels in btrfs is tracked by a btrfs_space_info structure, and all of the current space_infos are collected into a list_head. Most filesystems have 3 or 4 of these structs total, and the list is only changed when new raid levels are added or at unmount time. This commit adds rcu locking on the list head, and properly frees things at unmount time. It also clears the space_info->full flag whenever new space is added to the FS. The locking for the space info list goes like this: reads: protected by rcu_read_lock() writes: protected by the chunk_mutex At unmount time we don't need special locking because all the readers are gone. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-09Btrfs: fix spinlock assertions on UP systemsChris Mason
btrfs_tree_locked was being used to make sure a given extent_buffer was properly locked in a few places. But, it wasn't correct for UP compiled kernels. This switches it to using assert_spin_locked instead, and renames it to btrfs_assert_tree_locked to better reflect how it was really being used. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-20Btrfs: try committing transaction before returning ENOSPCJosef Bacik
This fixes a problem where we could return -ENOSPC when we may actually have plenty of space, the space is just pinned. Instead of returning -ENOSPC immediately, commit the transaction first and then try and do the allocation again. This patch also does chunk allocation for metadata if we pass the 80% threshold for metadata space. This will help with stack usage since the chunk allocation will happen early on, instead of when the allocation is happening. Signed-off-by: Josef Bacik <jbacik@redhat.com>
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>
2009-02-20Btrfs: check file pointer in btrfs_sync_fileChris Mason
fsync can be called by NFS with a null file pointer, and btrfs was oopsing in this case. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-12Btrfs: hold trans_mutex when using btrfs_record_root_in_transYan Zheng
btrfs_record_root_in_trans needs the trans_mutex held to make sure two callers don't race to setup the root in a given transaction. This adds it to all the places that were missing it. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2009-02-12Btrfs: make a lockdep class for the extent buffer locksChris Mason
Btrfs is currently using spin_lock_nested with a nested value based on the tree depth of the block. But, this doesn't quite work because the max tree depth is bigger than what spin_lock_nested can deal with, and because locks are sometimes taken before the level field is filled in. The solution here is to use lockdep_set_class_and_name instead, and to set the class before unlocking the pages when the block is read from the disk and just after init of a freshly allocated tree block. btrfs_clear_path_blocking is also changed to take the locks in the proper order, and it also makes sure all the locks currently held are properly set to blocking before it tries to retake the spinlocks. Otherwise, lockdep gets upset about bad lock orderin. The lockdep magic cam from Peter Zijlstra <peterz@infradead.org> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-12Btrfs: fs/btrfs/volumes.c: remove useless kzallocJulia Lawall
The call to kzalloc is followed by a kmalloc whose result is stored in the same variable. The semantic match that finds the problem is as follows: (http://www.emn.fr/x-info/coccinelle/) // <smpl> @r exists@ local idexpression x; statement S; expression E; identifier f,l; position p1,p2; expression *ptr != NULL; @@ ( if ((x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...)) == NULL) S | x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...); ... if (x == NULL) S ) <... when != x when != if (...) { <+...x...+> } x->f = E ...> ( return \(0\|<+...x...+>\|ptr\); | return@p2 ...; ) @script:python@ p1 << r.p1; p2 << r.p2; @@ print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line) // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-12Btrfs: remove unused code in split_state()Qinghuang Feng
These two lines are not used, remove them. Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-12Btrfs: remove btrfs_init_pathJeff Mahoney
btrfs_init_path was initially used when the path objects were on the stack. Now all the work is done by btrfs_alloc_path and btrfs_init_path isn't required. This patch removes it, and just uses kmem_cache_zalloc to zero out the object. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-12Btrfs: balance_level checks !child after accessJeff Mahoney
The BUG_ON() is in the wrong spot. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-12Btrfs: Avoid using __GFP_HIGHMEM with slab allocatorYan Zheng
btrfs_releasepage may call kmem_cache_alloc indirectly, and provide same GFP flags it gets to kmem_cache_alloc. So it's possible to use __GFP_HIGHMEM with the slab allocator. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2009-02-12Btrfs: don't clean old snapshots on sync(1)Chris Mason
Cleaning old snapshots can make sync(1) somewhat slow, and some users and applications still use it in a global fsync kind of workload. This patch changes btrfs not to clean old snapshots during sync, which is safe from a FS consistency point of view. The major downside is that it makes it difficult to tell when old snapshots have been reaped and the space they were using has been reclaimed. A new ioctl will be added for this purpose instead. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-12Btrfs: use larger metadata clusters in ssd modeChris Mason
Larger metadata clusters can significantly improve writeback performance on ssd drives with large erasure blocks. The larger clusters make it more likely a given IO will completely overwrite the ssd block, so it doesn't have to do an internal rwm cycle. On spinning media, lager metadata clusters end up spreading out the metadata more over time, which makes fsck slower, so we don't want this to be the default. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-12Btrfs: process mount options on mount -o remount,Chris Mason
Btrfs wasn't parsing any new mount options during remount, making it difficult to set mount options on a root drive. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-12Btrfs: make sure all pending extent operations are completeJosef Bacik
Theres a slight problem with finish_current_insert, if we set all to 1 and then go through and don't actually skip any of the extents on the pending list, we could exit right after we've added new extents. This is a problem because by inserting the new extents we could have gotten new COW's to happen and such, so we may have some pending updates to do or even more inserts to do after that. So this patch will only exit if we have never skipped any of the extents in the pending list, and we have no extents to insert, this will make sure that all of the pending work is truly done before we return. I've been running with this patch for a few days with all of my other testing and have not seen issues. Thanks, Signed-off-by: Josef Bacik <jbacik@redhat.com>
2009-02-09Btrfs: don't use spin_is_contendedChris Mason
Btrfs was using spin_is_contended to see if it should drop locks before doing extent allocations during btrfs_search_slot. The idea was to avoid expensive searches in the tree unless the lock was actually contended. But, spin_is_contended is specific to the ticket spinlocks on x86, so this is causing compile errors everywhere else. In practice, the contention could easily appear some time after we started doing the extent allocation, and it makes more sense to always drop the lock instead. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-06Btrfs: Make sure dir is non-null before doing S_ISGID checksChris Mason
The S_ISGID check in btrfs_new_inode caused an oops during subvol creation because sometimes the dir is null. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-05Btrfs: Fix memory leak in cache_drop_leaf_refChris Mason
The code wasn't doing a kfree on the sorted array Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04Btrfs: don't return congestion in write_cache_pages as oftenChris Mason
On fast devices that go from congested to uncongested very quickly, pdflush is waiting too often in congestion_wait, and the FS is backing off to easily in write_cache_pages. For now, fix this on the btrfs side by only checking congestion after some bios have already gone down. Longer term a real fix is needed for pdflush, but that is a larger project. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04Btrfs: Only prep for btree deletion balances when nodes are mostly emptyChris Mason
Whenever an item deletion is done, we need to balance all the nodes in the tree to make sure we don't end up with an empty node if a pointer is deleted. This balance prep happens from the root of the tree down so we can drop our locks as we go. reada_for_balance was triggering read-ahead on neighboring nodes even when no balancing was required. This adds an extra check to avoid calling balance_level() and avoid reada_for_balance() when a balance won't be required. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04Btrfs: fix btrfs_unlock_up_safe to walk the entire pathChris Mason
btrfs_unlock_up_safe would break out at the first NULL node entry or unlocked node it found in the path. Some of the callers have missing nodes at the lower levels of the path, so this commit fixes things to check all the nodes in the path before returning. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04Btrfs: change btrfs_del_leaf to drop locks earlierChris Mason
btrfs_del_leaf does two things. First it removes the pointer in the parent, and then it frees the block that has the leaf. It has the parent node locked for both operations. But, it only needs the parent locked while it is deleting the pointer. After that it can safely free the block without the parent locked. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04Btrfs: Change btrfs_truncate_inode_items to stop when it hits the inodeChris Mason
btrfs_truncate_inode_items is setup to stop doing btree searches when it has finished removing the items for the inode. It used to detect the end of the inode by looking for an objectid that didn't match the one we were searching for. But, this would result in an extra search through the btree, which adds extra balancing and cow costs to the operation. This commit adds a check to see if we found the inode item, which means we can stop searching early. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04Btrfs: Don't try to compress pages past i_sizeChris Mason
The compression code had some checks to make sure we were only compressing bytes inside of i_size, but it wasn't catching every case. To make things worse, some incorrect math about the number of bytes remaining would make it try to compress more pages than the file really had. The fix used here is to fall back to the non-compression code in this case, which does all the proper cleanup of delalloc and other accounting. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04Btrfs: join the transaction in __btrfs_setxattrJosef Bacik
With selinux on we end up calling __btrfs_setxattr when we create an inode, which calls btrfs_start_transaction(). The problem is we've already called that in btrfs_new_inode, and in btrfs_start_transaction we end up doing a wait_current_trans(). If btrfs-transaction has started committing it will wait for all handles to finish, while the other process is waiting for the transaction to commit. This is fixed by using btrfs_join_transaction, which won't wait for the transaction to commit. Thanks, Signed-off-by: Josef Bacik <jbacik@redhat.com>
2009-02-04Btrfs: Handle SGID bit when creating inodesChris Ball
Before this patch, new files/dirs would ignore the SGID bit on their parent directory and always be owned by the creating user's uid/gid. Signed-off-by: Chris Ball <cjb@laptop.org> Signed-off-by: Chris Mason <chris.mason@oracle.com>