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path: root/fs/btrfs/ctree.c
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2012-06-15Btrfs: init old_generation in get_old_rootChris Mason
gcc was giving an uninit variable warning here. Strictly speaking we don't need to init it, but this will make things much less error prone. Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-06-14Btrfs: fix race in tree mod log additionJan Schmidt
When adding to the tree modification log, we grab two locks at different stages. We must not drop the outer lock until we're done with section protected by the inner lock. This moves the unlock call for the outer lock to the appropriate position. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-06-14Btrfs: add btrfs_next_old_leafJan Schmidt
To make sense of the tree mod log, the backref walker not only needs btrfs_search_old_slot, but it also called btrfs_next_leaf, which in turn was calling btrfs_search_slot. This obviously didn't give the correct result. This commit adds btrfs_next_old_leaf, a drop-in replacement for btrfs_next_leaf with a time_seq parameter. If it is zero, it behaves exactly like btrfs_next_leaf. If it is non-zero, it will use btrfs_search_old_slot with this time_seq parameter. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-06-14Btrfs: fix return value for __tree_mod_log_oldest_rootJan Schmidt
In __tree_mod_log_oldest_root() we must return the found operation even if it's not a ROOT_REPLACE operation. Otherwise, the caller assumes that there are no operations to be rewinded and returns immediately. The code in the caller is modified to improve readability. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-06-14Btrfs: use btrfs_read_lock_root_node in get_old_rootJan Schmidt
get_old_root could race with root node updates because we weren't locking the node early enough. Use btrfs_read_lock_root_node to grab the root locked in the very beginning and release the lock as soon as possible (just like btrfs_search_slot does). Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-06-04Btrfs: remove call to btrfs_header_nritems with no effectJan Schmidt
This is a leftover from cleanup patch 559af821. Before the cleanup, btrfs_header_nritems was called inside an if condition. As it has no side effects we need to preserve here, it should simply be dropped. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-05-31Merge branch 'for-chris' of git://git.jan-o-sch.net/btrfs-unstable into ↵Chris Mason
for-linus Conflicts: fs/btrfs/ulist.h Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-05-31Btrfs: fix tree mod log rewinded level and rewinding of moved keysJan Schmidt
When we rewind REMOVE_WHILE_FREEING operations, there's code that allocates a fresh buffer instead of cloning the old one. Setting that buffer's level correctly was missing in this case. When rewinding a MOVE_KEYS operation, btrfs_node_key_ptr_offset(slot) was missing for memmove_extent_buffer()'s arguments. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-05-31Btrfs: fix tree mod log del_ptrJan Schmidt
Logging for del_ptr when we're not deleting the last pointer was wrong. This fixes both, duplicate log entries and log sequence. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-05-31Btrfs: add tree_mod_dont_log helperJan Schmidt
Replace duplicate code by small inline helper function. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-05-31Btrfs: add missing spin_lock for insertion into tree mod logJan Schmidt
tree_mod_alloc calls __get_tree_mod_seq and must acquire a spinlock before doing so. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-05-30Btrfs: return value of btrfs_read_buffer is checked correctlyTsutomu Itoh
btrfs_read_buffer() has the possibility of returning the error. Therefore, I add the code in which the return value of btrfs_read_buffer() is checked. Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
2012-05-30Btrfs: add btrfs_search_old_slotJan Schmidt
The tree modification log together with the current state of the tree gives a consistent, old version of the tree. btrfs_search_old_slot is used to search through this old version and return old (dummy!) extent buffers. Naturally, this function cannot do any tree modifications. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-05-30Btrfs: add del_ptr and insert_ptr modifications to the tree mod logJan Schmidt
Record all relevant modifications to block pointers in the tree mod log so that we can rewind them later on for backref walking. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-05-30Btrfs: put all block modifications into the tree mod logJan Schmidt
When running functions that can make changes to the internal trees (e.g. btrfs_search_slot), we check if somebody may be interested in the block we're currently modifying. If so, we record our modification to be able to rewind it later on. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-05-30Btrfs: add tree modification log functionsJan Schmidt
The tree mod log will log modifications made fs-tree nodes. Most modifications are done by autobalance of the tree. Such changes are recorded as long as a block entry exists. When released, the log is cleaned. With the tree modification log, it's possible to reconstruct a consistent old state of the tree. This is required to do backref walking on a busy file system. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-05-26Btrfs: don't set for_cow parameter for tree block functionsJan Schmidt
Three callers of btrfs_free_tree_block or btrfs_alloc_tree_block passed parameter for_cow = 1. In fact, these two functions should never mark their tree modification operations as for_cow, because they can change the number of blocks referenced by a tree. Hence, we remove the extra for_cow parameter from these functions and make them pass a zero down. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-05-11btrfs/ctree.c: remove the unnecessary 'return -1;' at the end of bin_searchWang Sheng-Hui
The code path should not reach there. Remove it. Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
2012-05-06Btrfs: avoid sleeping in verify_parent_transid while atomicChris Mason
verify_parent_transid needs to lock the extent range to make sure no IO is underway, and so it can safely clear the uptodate bits if our checks fail. But, a few callers are using it with spinlocks held. Most of the time, the generation numbers are going to match, and we don't want to switch to a blocking lock just for the error case. This adds an atomic flag to verify_parent_transid, and changes it to return EAGAIN if it needs to block to properly verifiy things. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-05-04Btrfs: Add properly locking around add_root_to_dirty_listChris Mason
add_root_to_dirty_list happens once at the very beginning of the transaction, but it is still racey. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-28Merge branch 'error-handling' into for-linusChris Mason
Conflicts: fs/btrfs/ctree.c fs/btrfs/disk-io.c fs/btrfs/extent-tree.c fs/btrfs/extent_io.c fs/btrfs/extent_io.h fs/btrfs/inode.c fs/btrfs/scrub.c Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-26Btrfs: adjust the write_lock_level as we unlockChris Mason
btrfs_search_slot sometimes needs write locks on high levels of the tree. It remembers the highest level that needs a write lock and will use that for all future searches through the tree in a given call. But, very often we'll just cow the top level or the level below and we won't really need write locks on the root again after that. This patch changes things to adjust the write lock requirement as it unlocks levels. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-26Btrfs: add the ability to cache a pointer into the ebChris Mason
This cuts down on the CPU time used by map_private_extent_buffer Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-03-26Btrfs: introduce free_extent_buffer_staleJosef Bacik
Because btrfs cow's we can end up with extent buffers that are no longer necessary just sitting around in memory. So instead of evicting these pages, we could end up evicting things we actually care about. Thus we have free_extent_buffer_stale for use when we are freeing tree blocks. This will make it so that the ref for the eb being in the radix tree is dropped as soon as possible and then is freed when the refcount hits 0 instead of waiting to be released by releasepage. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
2012-03-22btrfs: replace many BUG_ONs with proper error handlingJeff Mahoney
btrfs currently handles most errors with BUG_ON. This patch is a work-in- progress but aims to handle most errors other than internal logic errors and ENOMEM more gracefully. This iteration prevents most crashes but can run into lockups with the page lock on occasion when the timing "works out." Signed-off-by: Jeff Mahoney <jeffm@suse.com>
2012-03-22btrfs: Go readonly on tree errors in balance_levelMark Fasheh
balace_level() seems to deal with missing tree nodes by BUG_ON(). Instead, we can easily just set the file system readonly and bubble -EROFS back up the stack. Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2012-03-22btrfs: Don't BUG_ON errors from update_ref_for_cow()Mark Fasheh
__btrfs_cow_block(), the only caller of update_ref_for_cow() will BUG_ON() any error return. Instead, we can go read-only fs as update_ref_for_cow() manipulates disk data in a way which doesn't look like it's easily rolled back. Signed-off-by: Mark Fasheh <mfasheh@suse.de>
2012-03-22btrfs: Go readonly on bad extent refs in update_ref_for_cow()Mark Fasheh
update_ref_for_cow() will BUG_ON() after it's call to btrfs_lookup_extent_info() if no existing references are found. Since refs are computed directly from disk, this should be treated as a corruption instead of a logic error. Signed-off-by: Mark Fasheh <mfasheh@suse.de>
2012-03-22btrfs: Don't BUG_ON() errors in update_ref_for_cow()Mark Fasheh
The only caller of update_ref_for_cow() is __btrfs_cow_block() which was originally ignoring any return values. update_ref_for_cow() however doesn't look like a candidate to become a void function - there are a few places where errors can occur. So instead I changed update_ref_for_cow() to bubble all errors up (instead of BUG_ON). __btrfs_cow_block() was then updated to catch and BUG_ON() any errors from update_ref_for_cow(). The end effect is that we have no change in behavior, but about 8 different places where a BUG_ON(ret) was removed. Obviously a future patch will have to address the BUG_ON() in __btrfs_cow_block(). Signed-off-by: Mark Fasheh <mfasheh@suse.de>
2012-03-22btrfs: return void in functions without error conditionsJeff Mahoney
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
2011-12-22Btrfs: mark delayed refs as for cowArne Jansen
Add a for_cow parameter to add_delayed_*_ref and pass the appropriate value from every call site. The for_cow parameter will later on be used to determine if a ref will change anything with respect to qgroups. Delayed refs coming from relocation are always counted as for_cow, as they don't change subvol quota. Also pass in the fs_info for later use. btrfs_find_all_roots() will use this as an optimization, as changes that are for_cow will not change anything with respect to which root points to a certain leaf. Thus, we don't need to add the current sequence number to those delayed refs. Signed-off-by: Arne Jansen <sensille@gmx.net> Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2011-11-15Btrfs: fix tree corruption after multi-thread snapshots and inode_cache flushLiu Bo
The btrfs snapshotting code requires that once a root has been snapshotted, we don't change it during a commit. But there are two cases to lead to tree corruptions: 1) multi-thread snapshots can commit serveral snapshots in a transaction, and this may change the src root when processing the following pending snapshots, which lead to the former snapshots corruptions; 2) the free inode cache was changing the roots when it root the cache, which lead to corruptions. This fixes things by making sure we force COW the block after we create a snapshot during commiting a transaction, then any changes to the roots will result in COW, and we get all the fs roots and snapshot roots to be consistent. Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-10-20Btrfs: fix array bound checkingLi Zefan
Otherwise we can execced the array bound of path->slots[]. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2011-07-27Btrfs: remove lockdep magic from btrfs_next_leafChris Mason
Before the reader/writer locks, btrfs_next_leaf needed to keep the path blocking to avoid making lockdep upset. Now that btrfs_next_leaf only takes read locks, this isn't required. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-07-27Btrfs: switch the btrfs tree locks to reader/writerChris Mason
The btrfs metadata btree is the source of significant lock contention, especially in the root node. This commit changes our locking to use a reader/writer lock. The lock is built on top of rw spinlocks, and it extends the lock tracking to remember if we have a read lock or a write lock when we go to blocking. Atomics count the number of blocking readers or writers at any given time. It removes all of the adaptive spinning from the old code and uses only the spinning/blocking hints inside of btrfs to decide when it should continue spinning. In read heavy workloads this is dramatically faster. In write heavy workloads we're still faster because of less contention on the root node lock. We suffer slightly in dbench because we schedule more often during write locks, but all other benchmarks so far are improved. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-07-27Btrfs: stop using highmem for extent_buffersChris Mason
The extent_buffers have a very complex interface where we use HIGHMEM for metadata and try to cache a kmap mapping to access the memory. The next commit adds reader/writer locks, and concurrent use of this kmap cache would make it even more complex. This commit drops the ability to use HIGHMEM with extent buffers, and rips out all of the related code. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-06-09Btrfs: don't map extent buffer if path->skip_locking is setJosef Bacik
Arne's scrub stuff exposed a problem with mapping the extent buffer in reada_for_search. He searches the commit root with multiple threads and with skip_locking set, so we can race and overwrite node->map_token since node isn't locked. So fix this so that we only map the extent buffer if we don't already have a map_token and skip_locking isn't set. Without this patch scrub would panic almost immediately, with the patch it doesn't panic anymore. Thanks, Reported-by: Arne Jansen <sensille@gmx.net> Signed-off-by: Josef Bacik <josef@redhat.com>
2011-05-28Merge branch 'for-chris' ofChris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs-work into for-linus Conflicts: fs/btrfs/disk-io.c fs/btrfs/extent-tree.c fs/btrfs/free-space-cache.c fs/btrfs/inode.c fs/btrfs/transaction.c Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-23Merge branch 'cleanups_and_fixes' into inode_numbersChris Mason
Conflicts: fs/btrfs/tree-log.c fs/btrfs/volumes.c Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-23Btrfs: BUG_ON is deleted from the caller of btrfs_truncate_item & ↵Tsutomu Itoh
btrfs_extend_item Currently, btrfs_truncate_item and btrfs_extend_item returns only 0. So, the check by BUG_ON in the caller is unnecessary. Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-23Btrfs: don't always do readaheadJosef Bacik
Our readahead is sort of sloppy, and really isn't always needed. For example if ls is doing a stating ls (which is the default) it's going to stat in non-disk order, so if say you have a directory with a stupid amount of files, readahead is going to do nothing but waste time in the case of doing the stat. Taking the unconditional readahead out made my test go from 57 minutes to 36 minutes. This means that everywhere we do loop through the tree we want to make sure we do set path->reada properly, so I went through and found all of the places where we loop through the path and set reada to 1. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
2011-05-23Btrfs: don't look at the extent buffer level 3 times in a rowJosef Bacik
We have a bit of debugging in btrfs_search_slot to make sure the level of the cow block is the same as the original block we were cow'ing. I don't think I've ever seen this tripped, so kill it. This saves us 2 kmap's per level in our search. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
2011-05-23Btrfs: map the node block when looking for readahead targetsJosef Bacik
If we have particularly full nodes, we could call btrfs_node_blockptr up to 32 times, which is 32 pairs of kmap/kunmap, which _sucks_. So go ahead and map the extent buffer while we look for readahead targets. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
2011-05-22Merge branch 'cleanups' of git://repo.or.cz/linux-2.6/btrfs-unstable into ↵Chris Mason
inode_numbers Conflicts: fs/btrfs/extent-tree.c fs/btrfs/free-space-cache.c fs/btrfs/inode.c fs/btrfs/tree-log.c Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-21btrfs: implement delayed inode items operationMiao Xie
Changelog V5 -> V6: - Fix oom when the memory load is high, by storing the delayed nodes into the root's radix tree, and letting btrfs inodes go. Changelog V4 -> V5: - Fix the race on adding the delayed node to the inode, which is spotted by Chris Mason. - Merge Chris Mason's incremental patch into this patch. - Fix deadlock between readdir() and memory fault, which is reported by Itaru Kitayama. Changelog V3 -> V4: - Fix nested lock, which is reported by Itaru Kitayama, by updating space cache inode in time. Changelog V2 -> V3: - Fix the race between the delayed worker and the task which does delayed items balance, which is reported by Tsutomu Itoh. - Modify the patch address David Sterba's comment. - Fix the bug of the cpu recursion spinlock, reported by Chris Mason Changelog V1 -> V2: - break up the global rb-tree, use a list to manage the delayed nodes, which is created for every directory and file, and used to manage the delayed directory name index items and the delayed inode item. - introduce a worker to deal with the delayed nodes. Compare with Ext3/4, the performance of file creation and deletion on btrfs is very poor. the reason is that btrfs must do a lot of b+ tree insertions, such as inode item, directory name item, directory name index and so on. If we can do some delayed b+ tree insertion or deletion, we can improve the performance, so we made this patch which implemented delayed directory name index insertion/deletion and delayed inode update. Implementation: - introduce a delayed root object into the filesystem, that use two lists to manage the delayed nodes which are created for every file/directory. One is used to manage all the delayed nodes that have delayed items. And the other is used to manage the delayed nodes which is waiting to be dealt with by the work thread. - Every delayed node has two rb-tree, one is used to manage the directory name index which is going to be inserted into b+ tree, and the other is used to manage the directory name index which is going to be deleted from b+ tree. - introduce a worker to deal with the delayed operation. This worker is used to deal with the works of the delayed directory name index items insertion and deletion and the delayed inode update. When the delayed items is beyond the lower limit, we create works for some delayed nodes and insert them into the work queue of the worker, and then go back. When the delayed items is beyond the upper bound, we create works for all the delayed nodes that haven't been dealt with, and insert them into the work queue of the worker, and then wait for that the untreated items is below some threshold value. - When we want to insert a directory name index into b+ tree, we just add the information into the delayed inserting rb-tree. And then we check the number of the delayed items and do delayed items balance. (The balance policy is above.) - When we want to delete a directory name index from the b+ tree, we search it in the inserting rb-tree at first. If we look it up, just drop it. If not, add the key of it into the delayed deleting rb-tree. Similar to the delayed inserting rb-tree, we also check the number of the delayed items and do delayed items balance. (The same to inserting manipulation) - When we want to update the metadata of some inode, we cached the data of the inode into the delayed node. the worker will flush it into the b+ tree after dealing with the delayed insertion and deletion. - We will move the delayed node to the tail of the list after we access the delayed node, By this way, we can cache more delayed items and merge more inode updates. - If we want to commit transaction, we will deal with all the delayed node. - the delayed node will be freed when we free the btrfs inode. - Before we log the inode items, we commit all the directory name index items and the delayed inode update. I did a quick test by the benchmark tool[1] and found we can improve the performance of file creation by ~15%, and file deletion by ~20%. Before applying this patch: Create files: Total files: 50000 Total time: 1.096108 Average time: 0.000022 Delete files: Total files: 50000 Total time: 1.510403 Average time: 0.000030 After applying this patch: Create files: Total files: 50000 Total time: 0.932899 Average time: 0.000019 Delete files: Total files: 50000 Total time: 1.215732 Average time: 0.000024 [1] http://marc.info/?l=linux-btrfs&m=128212635122920&q=p3 Many thanks for Kitayama-san's help! Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Reviewed-by: David Sterba <dave@jikos.cz> Tested-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Tested-by: Itaru Kitayama <kitayama@cl.bb4u.ne.jp> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-02btrfs: drop unused parameter from btrfs_release_pathDavid Sterba
parameter tree root it's not used since commit 5f39d397dfbe140a14edecd4e73c34ce23c4f9ee ("Btrfs: Create extent_buffer interface for large blocksizes") Signed-off-by: David Sterba <dsterba@suse.cz>
2011-05-02btrfs: make functions static when possibleDavid Sterba
Signed-off-by: David Sterba <dsterba@suse.cz>
2011-05-02btrfs: remove nested duplicate variable declarationsDavid Sterba
Signed-off-by: David Sterba <dsterba@suse.cz>
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>
2011-03-28Btrfs: cleanup some BUG_ON()Tsutomu Itoh
This patch changes some BUG_ON() to the error return. (but, most callers still use BUG_ON()) Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>