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2015-03-25Merge branch 'cleanups-post-3.19' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.1 Signed-off-by: Chris Mason <clm@fb.com> Conflicts: fs/btrfs/disk-io.c
2015-03-25Merge branch 'cleanups-for-4.1-v2' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.1
2015-03-03btrfs: cleanup, use kmalloc_array/kcalloc array helpersDavid Sterba
Convert kmalloc(nr * size, ..) to kmalloc_array that does additional overflow checks, the zeroing variant is kcalloc. Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-02Btrfs: fix off-by-one logic error in btrfs_realloc_nodeFilipe Manana
The end_slot variable actually matches the number of pointers in the node and not the last slot (which is 'nritems - 1'). Therefore in order to check that the current slot in the for loop doesn't match the last one, the correct logic is to check if 'i' is less than 'end_slot - 1' and not 'end_slot - 2'. Fix this and set end_slot to be 'nritems - 1', as it's less confusing since the variable name implies it's inclusive rather then exclusive. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-16Btrfs: disk-io: replace root args iff only fs_info usedDaniel Dressler
This is the 3rd independent patch of a larger project to cleanup btrfs's internal usage of btrfs_root. Many functions take btrfs_root only to grab the fs_info struct. By requiring a root these functions cause programmer overhead. That these functions can accept any valid root is not obvious until inspection. This patch reduces the specificity of such functions to accept the fs_info directly. These patches can be applied independently and thus are not being submitted as a patch series. There should be about 26 patches by the project's completion. Each patch will cleanup between 1 and 34 functions apiece. Each patch covers a single file's functions. This patch affects the following function(s): 1) csum_tree_block 2) csum_dirty_buffer 3) check_tree_block_fsid 4) btrfs_find_tree_block 5) clean_tree_block Signed-off-by: Daniel Dressler <danieru.dressler@gmail.com> Signed-off-by: David Sterba <dsterba@suse.cz>
2015-02-16Btrfs: ctree: reduce args where only fs_info usedDaniel Dressler
This patch is part of a larger project to cleanup btrfs's internal usage of struct btrfs_root. Many functions take btrfs_root only to grab a pointer to fs_info. This causes programmers to ponder which root can be passed. Since only the fs_info is read affected functions can accept any root, except this is only obvious upon inspection. This patch reduces the specificty of such functions to accept the fs_info directly. This patch does not address the two functions in ctree.c (insert_ptr, and split_item) which only use root for BUG_ONs in ctree.c This patch affects the following functions: 1) fixup_low_keys 2) btrfs_set_item_key_safe Signed-off-by: Daniel Dressler <danieru.dressler@gmail.com> Signed-off-by: David Sterba <dsterba@suse.cz>
2015-01-22Btrfs: insert_new_root: Fix lock type of the extent buffer.chandan
btrfs_alloc_tree_block() returns an extent buffer on which a blocked lock has been taken. Hence assign the appropriate value to path->locks[level]. Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: fix setup_leaf_for_split() to avoid leaf corruptionFilipe Manana
We were incorrectly detecting when the target key didn't exist anymore after releasing the path and re-searching the tree. This could make us split or duplicate (btrfs_split_item() and btrfs_duplicate_item() are its only callers at the moment) an item when we should not. For the case of duplicating an item, we currently only duplicate checksum items (csum tree) and file extent items (fs/subvol trees). For the checksum items we end up overriding the item completely, but for file extent items we update only some of their fields in the copy (done in __btrfs_drop_extents), which means we can end up having a logical corruption for some values. Also for the case where we duplicate a file extent item it will make us produce a leaf with a wrong key order, as btrfs_duplicate_item() advances us to the next slot and then its caller sets a smaller key on the new item at that slot (like in __btrfs_drop_extents() e.g.). Alternatively if the tree search in setup_leaf_for_split() leaves with path->slots[0] == btrfs_header_nritems(path->nodes[0]), we end up accessing beyond the leaf's end (when we check if the item's size has changed) and make our caller insert an item at the invalid slot btrfs_header_nritems(path->nodes[0]) + 1, causing an invalid memory access if the leaf is full or nearly full. This issue has been present since the introduction of this function in 2009: Btrfs: Add btrfs_duplicate_item commit ad48fd754676bfae4139be1a897b1ea58f9aaf21 Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Merge branch 'cleanup/blocksize-diet-part2' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus
2015-01-22Merge branch 'fix/find-item-path-leak' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus
2015-01-22Btrfs: change how we track dirty rootsJosef Bacik
I've been overloading root->dirty_list to keep track of dirty roots and which roots need to have their commit roots switched at transaction commit time. This could cause us to lose an update to the root which could corrupt the file system. To fix this use a state bit to know if the root is dirty, and if it isn't set we go ahead and move the root to the dirty list. This way if we re-dirty the root after adding it to the switch_commit list we make sure to update it. This also makes it so that the extent root is always the last root on the dirty list to try and keep the amount of churn down at this point in the commit. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-14btrfs: expand btrfs_find_item if found_key is NULLDavid Sterba
If the found_key is NULL, then btrfs_find_item becomes a verbose wrapper for simple btrfs_search_slot. After we've removed all such callers, passing a NULL key is not valid anymore. Signed-off-by: David Sterba <dsterba@suse.cz>
2015-01-14btrfs: fix leak of path in btrfs_find_itemDavid Sterba
If btrfs_find_item is called with NULL path it allocates one locally but does not free it. Affected paths are inserting an orphan item for a file and for a subvol root. Move the path allocation to the callers. CC: <stable@vger.kernel.org> # 3.14+ Fixes: 3f870c289900 ("btrfs: expand btrfs_find_item() to include find_orphan_item functionality") Signed-off-by: David Sterba <dsterba@suse.cz>
2014-12-12btrfs: unify extent buffer allocation apiDavid Sterba
Make the extent buffer allocation interface consistent. Cloned eb will set a valid fs_info. For dummy eb, we can drop the length parameter and set it from fs_info. The built-in sanity checks may pass a NULL fs_info that's queried for nodesize, but we know it's 4096. Signed-off-by: David Sterba <dsterba@suse.cz>
2014-12-12btrfs: sink blocksize parameter to readahead_tree_blockDavid Sterba
All callers pass nodesize. Signed-off-by: David Sterba <dsterba@suse.cz>
2014-12-03Merge branch 'raid56-scrub-replace' of git://github.com/miaoxie/linux-btrfs ↵Chris Mason
into for-linus
2014-11-21Btrfs: make xattr replace operations atomicFilipe Manana
Replacing a xattr consists of doing a lookup for its existing value, delete the current value from the respective leaf, release the search path and then finally insert the new value. This leaves a time window where readers (getxattr, listxattrs) won't see any value for the xattr. Xattrs are used to store ACLs, so this has security implications. This change also fixes 2 other existing issues which were: *) Deleting the old xattr value without verifying first if the new xattr will fit in the existing leaf item (in case multiple xattrs are packed in the same item due to name hash collision); *) Returning -EEXIST when the flag XATTR_CREATE is given and the xattr doesn't exist but we have have an existing item that packs muliple xattrs with the same name hash as the input xattr. In this case we should return ENOSPC. A test case for xfstests follows soon. Thanks to Alexandre Oliva for reporting the non-atomicity of the xattr replace implementation. Reported-by: Alexandre Oliva <oliva@gnu.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-11-19btrfs: fix lockups from btrfs_clear_path_blockingChris Mason
The fair reader/writer locks mean that btrfs_clear_path_blocking needs to strictly follow lock ordering rules even when we already have blocking locks on a given path. Before we can clear a blocking lock on the path, we need to make sure all of the locks have been converted to blocking. This will remove lock inversions against anyone spinning in write_lock() against the buffers we're trying to get read locks on. These inversions didn't exist before the fair read/writer locks, but now we need to be more careful. We papered over this deadlock in the past by changing btrfs_try_read_lock() to be a true trylock against both the spinlock and the blocking lock. This was slower, and not sufficient to fix all the deadlocks. This patch adds a btrfs_tree_read_lock_atomic(), which basically means get the spinlock but trylock on the blocking lock. Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Reported-by: Patrick Schmid <schmid@phys.ethz.ch> cc: stable@vger.kernel.org #v3.15+
2014-10-04Merge branch 'cleanup/blocksize-diet-part1' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus
2014-10-04Merge branch 'cleanup/misc-for-3.18' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus Signed-off-by: Chris Mason <clm@fb.com> Conflicts: fs/btrfs/extent_io.c
2014-10-03btrfs: fix shadow warning on cmpFabian Frederick
cmp was declared twice in btrfs_compare_trees resulting in a shadow warning. This patch renames second internal variable. Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Chris Mason <clm@fb.com>
2014-10-02btrfs: move checks for DUMMY_ROOT into a helperDavid Sterba
Signed-off-by: David Sterba <dsterba@suse.cz>
2014-10-02btrfs: new define for the inline extent data startDavid Sterba
Use a common definition for the inline data start so we don't have to open-code it and introduce bugs like "Btrfs: fix wrong max inline data size limit" fixed. Signed-off-by: David Sterba <dsterba@suse.cz>
2014-10-02btrfs: remove blocksize from btrfs_alloc_free_block and renameDavid Sterba
Rename to btrfs_alloc_tree_block as it fits to the alloc/find/free + _tree_block family. The parameter blocksize was set to the metadata block size, directly or indirectly. Signed-off-by: David Sterba <dsterba@suse.cz>
2014-10-02btrfs: remove unused parameter blocksize from btrfs_find_tree_blockDavid Sterba
Signed-off-by: David Sterba <dsterba@suse.cz>
2014-10-02btrfs: remove parameter blocksize from read_tree_blockDavid Sterba
We know the tree block size, no need to pass it around. Signed-off-by: David Sterba <dsterba@suse.cz>
2014-10-02btrfs: remove unused parameter from readahead_tree_blockDavid Sterba
The parent_transid parameter has been unused since its introduction in ca7a79ad8dbe2466 ("Pass down the expected generation number when reading tree blocks"). In reada_tree_block, it was even wrongly set to leafsize. Transid check is done in the proper read and readahead ignores errors. Signed-off-by: David Sterba <dsterba@suse.cz>
2014-09-17Btrfs: make btrfs_search_forward return with nodes unlockedFilipe Manana
None of the uses of btrfs_search_forward() need to have the path nodes (level >= 1) read locked, only the leaf needs to be locked while the caller processes it. Therefore make it return a path with all nodes unlocked, except for the leaf. This change is motivated by the observation that during a file fsync we repeatdly call btrfs_search_forward() and process the returned leaf while upper nodes of the returned path (level >= 1) are read locked, which unnecessarily blocks other tasks that want to write to the same fs/subvol btree. Therefore instead of modifying the fsync code to unlock all nodes with level >= 1 immediately after calling btrfs_search_forward(), change btrfs_search_forward() to do it, so that it benefits all callers. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17Btrfs: avoid unnecessary switch of path locks to blocking modeFilipe Manana
If we need to cow a node, increase the write lock level and retry the tree search, there's no point of changing the node locks in our path to blocking mode, as we only waste time and unnecessarily wake up other tasks waiting on the spinning locks (just to block them again shortly after) because we release our path before repeating the tree search. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17Btrfs: unlock nodes earlier when inserting items in a btreeFilipe Manana
In ctree.c:setup_items_for_insert(), we can unlock all nodes in our path before we process the leaf (shift items and data, adjust data offsets, etc). This allows for better btree concurrency, as we're often holding a write lock on at least the node at level 1. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17btrfs: use nodesize everywhere, kill leafsizeDavid Sterba
The nodesize and leafsize were never of different values. Unify the usage and make nodesize the one. Cleanup the redundant checks and helpers. Shaves a few bytes from .text: text data bss dec hex filename 852418 24560 23112 900090 dbbfa btrfs.ko.before 851074 24584 23112 898770 db6d2 btrfs.ko.after Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2014-08-15Btrfs: __btrfs_mod_ref should always use no_quotaJosef Bacik
Before I extended the no_quota arg to btrfs_dec/inc_ref because I didn't understand how snapshot delete was using it and assumed that we needed the quota operations there. With Mark's work this has turned out to be not the case, we _always_ need to use no_quota for btrfs_dec/inc_ref, so just drop the argument and make __btrfs_mod_ref call it's process function with no_quota set always. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-06-10Btrfs: fix leaf corruption after __btrfs_drop_extentsLiu Bo
Several reports about leaf corruption has been floating on the list, one of them points to __btrfs_drop_extents(), and we find that the leaf becomes corrupted after __btrfs_drop_extents(), it's really a rare case but it does exist. The problem turns out to be btrfs_next_leaf() called in __btrfs_drop_extents(). So in btrfs_next_leaf(), we release the current path to re-search the last key of the leaf for locating next leaf, and we've taken it into account that there might be balance operations between leafs during this 'unlock and re-lock' dance, so we check the path again and advance it if there are now more items available. But things are a bit different if that last key happens to be removed and balance gets a bigger key as the last one, and btrfs_search_slot will return it with ret > 0, IOW, nothing change in this leaf except the new last key, then we think we're okay because there is no more item balanced in, fine, we thinks we can go to the next leaf. However, we should return that bigger key, otherwise we deserve leaf corruption, for example, in endio, skipping that key means that __btrfs_drop_extents() thinks it has dropped all extent matched the required range and finish_ordered_io can safely insert a new extent, but it actually doesn't and ends up a leaf corruption. One may be asking that why our locking on extent io tree doesn't work as expected, ie. it should avoid this kind of race situation. But in __btrfs_drop_extents(), we don't always find extents which are included within our locking range, IOW, extents can start before our searching start, in this case locking on extent io tree doesn't protect us from the race. This takes the special case into account. Reviewed-by: Filipe Manana <fdmanana@gmail.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-06-10Btrfs: ensure btrfs_prev_leaf doesn't miss 1 itemFilipe Manana
We might have had an item with the previous key in the tree right before we released our path. And after we released our path, that item might have been pushed to the first slot (0) of the leaf we were holding due to a tree balance. Alternatively, an item with the previous key can exist as the only element of a leaf (big fat item). Therefore account for these 2 cases, so that our callers (like btrfs_previous_item) don't miss an existing item with a key matching the previous key we computed above. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-06-10Btrfs: add sanity tests for new qgroup accounting codeJosef Bacik
This exercises the various parts of the new qgroup accounting code. We do some basic stuff and do some things with the shared refs to make sure all that code works. I had to add a bunch of infrastructure because I needed to be able to insert items into a fake tree without having to do all the hard work myself, hopefully this will be usefull in the future. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-06-10Btrfs: rework qgroup accountingJosef Bacik
Currently qgroups account for space by intercepting delayed ref updates to fs trees. It does this by adding sequence numbers to delayed ref updates so that it can figure out how the tree looked before the update so we can adjust the counters properly. The problem with this is that it does not allow delayed refs to be merged, so if you say are defragging an extent with 5k snapshots pointing to it we will thrash the delayed ref lock because we need to go back and manually merge these things together. Instead we want to process quota changes when we know they are going to happen, like when we first allocate an extent, we free a reference for an extent, we add new references etc. This patch accomplishes this by only adding qgroup operations for real ref changes. We only modify the sequence number when we need to lookup roots for bytenrs, this reduces the amount of churn on the sequence number and allows us to merge delayed refs as we add them most of the time. This patch encompasses a bunch of architectural changes 1) qgroup ref operations: instead of tracking qgroup operations through the delayed refs we simply add new ref operations whenever we notice that we need to when we've modified the refs themselves. 2) tree mod seq: we no longer have this separation of major/minor counters. this makes the sequence number stuff much more sane and we can remove some locking that was needed to protect the counter. 3) delayed ref seq: we now read the tree mod seq number and use that as our sequence. This means each new delayed ref doesn't have it's own unique sequence number, rather whenever we go to lookup backrefs we inc the sequence number so we can make sure to keep any new operations from screwing up our world view at that given point. This allows us to merge delayed refs during runtime. With all of these changes the delayed ref stuff is a little saner and the qgroup accounting stuff no longer goes negative in some cases like it was before. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-06-10Btrfs: use bitfield instead of integer data type for the some variants in ↵Miao Xie
btrfs_root Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-04-07Btrfs: hold the commit_root_sem when getting the commit root during sendJosef Bacik
We currently rely too heavily on roots being read-only to save us from just accessing root->commit_root. We can easily balance blocks out from underneath a read only root, so to save us from getting screwed make sure we only access root->commit_root under the commit root sem. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-04-07Btrfs: remove transaction from sendJosef Bacik
Lets try this again. We can deadlock the box if we send on a box and try to write onto the same fs with the app that is trying to listen to the send pipe. This is because the writer could get stuck waiting for a transaction commit which is being blocked by the send. So fix this by making sure looking at the commit roots is always going to be consistent. We do this by keeping track of which roots need to have their commit roots swapped during commit, and then taking the commit_root_sem and swapping them all at once. Then make sure we take a read lock on the commit_root_sem in cases where we search the commit root to make sure we're always looking at a consistent view of the commit roots. Previously we had problems with this because we would swap a fs tree commit root and then swap the extent tree commit root independently which would cause the backref walking code to screw up sometimes. With this patch we no longer deadlock and pass all the weird send/receive corner cases. Thanks, Reportedy-by: Hugo Mills <hugo@carfax.org.uk> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-03-10Btrfs: correctly determine if blocks are shared in btrfs_compare_treesFilipe Manana
Just comparing the pointers (logical disk addresses) of the btree nodes is not completely bullet proof, we have to check if their generation numbers match too. It is guaranteed that a COW operation will result in a block with a different logical disk address than the original block's address, but over time we can reuse that former logical disk address. For example, creating a 2Gb filesystem on a loop device, and having a script running in a loop always updating the access timestamp of a file, resulted in the same logical disk address being reused for the same fs btree block in about only 4 minutes. This could make us skip entire subtrees when doing an incremental send (which is currently the only user of btrfs_compare_trees). However the odds of getting 2 blocks at the same tree level, with the same logical disk address, equal first slot keys and different generations, should hopefully be very low. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Josef Bacik <jbacik@fb.com>
2014-01-29Btrfs: fix btrfs_search_slot_for_read backwards iterationFilipe David Borba Manana
If the current path's leaf slot is 0, we do search for the previous leaf (via btrfs_prev_leaf) and set the new path's leaf slot to a value corresponding to the number of items - 1 of the former leaf. Fix this by using the slot set by btrfs_prev_leaf, decrementing it by 1 if it's equal to the leaf's number of items. Use of btrfs_search_slot_for_read() for backward iteration is used in particular by the send feature, which could miss items when the input leaf has less items than its previous leaf. This could be reproduced by running btrfs/007 from xfstests in a loop. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28Btrfs: fix to search previous metadata extent item since skinny metadataWang Shilong
There is a bug that using btrfs_previous_item() to search metadata extent item. This is because in btrfs_previous_item(), we need type match, however, since skinny metada was introduced by josef, we may mix this two types. So just use btrfs_previous_item() is not working right. To keep btrfs_previous_item() like normal tree search, i introduce another function btrfs_previous_extent_item(). Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28Btrfs: reduce btree node locking duration on item updateFilipe David Borba Manana
If we do a btree search with the goal of updating an existing item without changing its size (ins_len == 0 and cow == 1), then we never need to hold locks on upper level nodes (even when slot == 0) after we COW their child nodes/leaves, as we won't have node splits or merges in this scenario (that is, no key additions, removals or shifts on any nodes or leaves). Therefore release the locks immediately after COWing the child nodes/leaves while navigating the btree, even if their parent slot is 0, instead of returning a path to the caller with those nodes locked, which would get released only when the caller releases or frees the path (or if it calls btrfs_unlock_up_safe). This is a common scenario, for example when updating inode items in fs trees and block group items in the extent tree. The following benchmarks were performed on a quad core machine with 32Gb of ram, using a leaf/node size of 4Kb (to generate deeper fs trees more quickly). sysbench --test=fileio --file-num=131072 --file-total-size=8G \ --file-test-mode=seqwr --num-threads=512 --file-block-size=8192 \ --max-requests=100000 --file-io-mode=sync [prepare|run] Before this change: 49.85Mb/s (average of 5 runs) After this change: 50.38Mb/s (average of 5 runs) Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28Btrfs: convert printk to btrfs_ and fix BTRFS prefixFrank Holton
Convert all applicable cases of printk and pr_* to the btrfs_* macros. Fix all uses of the BTRFS prefix. Signed-off-by: Frank Holton <fholton@gmail.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28Btrfs: fix tree mod loggingFilipe David Borba Manana
While running the test btrfs/004 from xfstests in a loop, it failed about 1 time out of 20 runs in my desktop. The failure happened in the backref walking part of the test, and the test's error message was like this: btrfs/004 93s ... [failed, exit status 1] - output mismatch (see /home/fdmanana/git/hub/xfstests_2/results//btrfs/004.out.bad) --- tests/btrfs/004.out 2013-11-26 18:25:29.263333714 +0000 +++ /home/fdmanana/git/hub/xfstests_2/results//btrfs/004.out.bad 2013-12-10 15:25:10.327518516 +0000 @@ -1,3 +1,8 @@ QA output created by 004 *** test backref walking -*** done +unexpected output from + /home/fdmanana/git/hub/btrfs-progs/btrfs inspect-internal logical-resolve -P 141512704 /home/fdmanana/btrfs-tests/scratch_1 +expected inum: 405, expected address: 454656, file: /home/fdmanana/btrfs-tests/scratch_1/snap1/p0/d6/d3d/d156/fce, got: + ... (Run 'diff -u tests/btrfs/004.out /home/fdmanana/git/hub/xfstests_2/results//btrfs/004.out.bad' to see the entire diff) Ran: btrfs/004 Failures: btrfs/004 Failed 1 of 1 tests But immediately after the test finished, the btrfs inspect-internal command returned the expected output: $ btrfs inspect-internal logical-resolve -P 141512704 /home/fdmanana/btrfs-tests/scratch_1 inode 405 offset 454656 root 258 inode 405 offset 454656 root 5 It turned out this was because the btrfs_search_old_slot() calls performed during backref walking (backref.c:__resolve_indirect_ref) were not finding anything. The reason for this turned out to be that the tree mod logging code was not logging some node multi-step operations atomically, therefore btrfs_search_old_slot() callers iterated often over an incomplete tree that wasn't fully consistent with any tree state from the past. Besides missing items, this often (but not always) resulted in -EIO errors during old slot searches, reported in dmesg like this: [ 4299.933936] ------------[ cut here ]------------ [ 4299.933949] WARNING: CPU: 0 PID: 23190 at fs/btrfs/ctree.c:1343 btrfs_search_old_slot+0x57b/0xab0 [btrfs]() [ 4299.933950] Modules linked in: btrfs raid6_pq xor pci_stub vboxpci(O) vboxnetadp(O) vboxnetflt(O) vboxdrv(O) bnep rfcomm bluetooth parport_pc ppdev binfmt_misc joydev snd_hda_codec_h [ 4299.933977] CPU: 0 PID: 23190 Comm: btrfs Tainted: G W O 3.12.0-fdm-btrfs-next-16+ #70 [ 4299.933978] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./Z77 Pro4, BIOS P1.50 09/04/2012 [ 4299.933979] 000000000000053f ffff8806f3fd98f8 ffffffff8176d284 0000000000000007 [ 4299.933982] 0000000000000000 ffff8806f3fd9938 ffffffff8104a81c ffff880659c64b70 [ 4299.933984] ffff880659c643d0 ffff8806599233d8 ffff880701e2e938 0000160000000000 [ 4299.933987] Call Trace: [ 4299.933991] [<ffffffff8176d284>] dump_stack+0x55/0x76 [ 4299.933994] [<ffffffff8104a81c>] warn_slowpath_common+0x8c/0xc0 [ 4299.933997] [<ffffffff8104a86a>] warn_slowpath_null+0x1a/0x20 [ 4299.934003] [<ffffffffa065d3bb>] btrfs_search_old_slot+0x57b/0xab0 [btrfs] [ 4299.934005] [<ffffffff81775f3b>] ? _raw_read_unlock+0x2b/0x50 [ 4299.934010] [<ffffffffa0655001>] ? __tree_mod_log_search+0x81/0xc0 [btrfs] [ 4299.934019] [<ffffffffa06dd9b0>] __resolve_indirect_refs+0x130/0x5f0 [btrfs] [ 4299.934027] [<ffffffffa06a21f1>] ? free_extent_buffer+0x61/0xc0 [btrfs] [ 4299.934034] [<ffffffffa06de39c>] find_parent_nodes+0x1fc/0xe40 [btrfs] [ 4299.934042] [<ffffffffa06b13e0>] ? defrag_lookup_extent+0xe0/0xe0 [btrfs] [ 4299.934048] [<ffffffffa06b13e0>] ? defrag_lookup_extent+0xe0/0xe0 [btrfs] [ 4299.934056] [<ffffffffa06df980>] iterate_extent_inodes+0xe0/0x250 [btrfs] [ 4299.934058] [<ffffffff817762db>] ? _raw_spin_unlock+0x2b/0x50 [ 4299.934065] [<ffffffffa06dfb82>] iterate_inodes_from_logical+0x92/0xb0 [btrfs] [ 4299.934071] [<ffffffffa06b13e0>] ? defrag_lookup_extent+0xe0/0xe0 [btrfs] [ 4299.934078] [<ffffffffa06b7015>] btrfs_ioctl+0xf65/0x1f60 [btrfs] [ 4299.934080] [<ffffffff811658b8>] ? handle_mm_fault+0x278/0xb00 [ 4299.934083] [<ffffffff81075563>] ? up_read+0x23/0x40 [ 4299.934085] [<ffffffff8177a41c>] ? __do_page_fault+0x20c/0x5a0 [ 4299.934088] [<ffffffff811b2946>] do_vfs_ioctl+0x96/0x570 [ 4299.934090] [<ffffffff81776e23>] ? error_sti+0x5/0x6 [ 4299.934093] [<ffffffff810b71e8>] ? trace_hardirqs_off_caller+0x28/0xd0 [ 4299.934096] [<ffffffff81776a09>] ? retint_swapgs+0xe/0x13 [ 4299.934098] [<ffffffff811b2eb1>] SyS_ioctl+0x91/0xb0 [ 4299.934100] [<ffffffff813eecde>] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 4299.934102] [<ffffffff8177ef12>] system_call_fastpath+0x16/0x1b [ 4299.934102] [<ffffffff8177ef12>] system_call_fastpath+0x16/0x1b [ 4299.934104] ---[ end trace 48f0cfc902491414 ]--- [ 4299.934378] btrfs bad fsid on block 0 These tree mod log operations that must be performed atomically, tree_mod_log_free_eb, tree_mod_log_eb_copy, tree_mod_log_insert_root and tree_mod_log_insert_move, used to be performed atomically before the following commit: c8cc6341653721b54760480b0d0d9b5f09b46741 (Btrfs: stop using GFP_ATOMIC for the tree mod log allocations) That change removed the atomicity of such operations. This patch restores the atomicity while still not doing the GFP_ATOMIC allocations of tree_mod_elem structures, so it has to do the allocations using GFP_NOFS before acquiring the mod log lock. This issue has been experienced by several users recently, such as for example: http://www.spinics.net/lists/linux-btrfs/msg28574.html After running the btrfs/004 test for 679 consecutive iterations with this patch applied, I didn't ran into the issue anymore. Cc: stable@vger.kernel.org Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28Btrfs: return immediately if tree log mod is not necessaryFilipe David Borba Manana
In ctree.c:tree_mod_log_set_node_key() we were calling __tree_mod_log_insert_key() even when the modification doesn't need to be logged. This would allocate a tree_mod_elem structure, fill it and pass it to __tree_mod_log_insert(), which would just acquire the tree mod log write lock and then free the tree_mod_elem structure and return (that is, a no-op). Therefore call tree_mod_log_insert() instead of __tree_mod_log_insert() which just returns immediately if the modification doesn't need to be logged (without allocating the structure, fill it, acquire write lock, free structure). Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28Btrfs: more efficient push_leaf_rightFilipe David Borba Manana
Currently when finding the leaf to insert a key into a btree, if the leaf doesn't have enough space to store the item we attempt to move off some items from our leaf to its right neighbor leaf, and if this fails to create enough free space in our leaf, we try to move off more items to the left neighbor leaf as well. When trying to move off items to the right neighbor leaf, if it has enough room to store the new key but not not enough room to move off at least one item from our target leaf, __push_leaf_right returns 1 and we have to attempt to move items to the left neighbor (push_leaf_left function) without touching the right neighbor leaf. For the case where the right leaf has enough room to store at least 1 item from our leaf, we end up modifying (and dirtying) both our leaf and the right leaf. This is non-optimal for the case where the new key is greater than any key in our target leaf because it can be inserted at slot 0 of the right neighbor leaf and we don't need to touch our leaf at all nor to attempt to move off items to the left neighbor leaf. Therefore this change just selects the right neighbor leaf as our new target leaf if it has enough room for the new key without modifying our initial target leaf - we do this only if the new key is higher than any key in the initial target leaf. While running the following test, push_leaf_right was called by split_leaf 4802 times. Out of those 4802 calls, for 2571 calls (53.5%) we hit this special case (right leaf has enough room and new key is higher than any key in the initial target leaf). Test: sysbench --test=fileio --file-num=512 --file-total-size=5G \ --file-test-mode=[seqwr|rndwr] --num-threads=512 --file-block-size=8192 \ --max-requests=100000 --file-io-mode=sync [prepare|run] Results: sequential writes Throughput before this change: 65.71Mb/sec (average of 10 runs) Throughput after this change: 66.58Mb/sec (average of 10 runs) random writes Throughput before this change: 10.75Mb/sec (average of 10 runs) Throughput after this change: 11.56Mb/sec (average of 10 runs) Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28Btrfs: try harder to avoid btree node splitsFilipe David Borba Manana
When attempting to move items from our target leaf to its neighbor leaves (right and left), we only need to free data_size - free_space bytes from our leaf in order to add the new item (which has size of data_size bytes). Therefore attempt to move items to the right and left leaves if they have at least data_size - free_space bytes free, instead of data_size bytes free. After 5 runs of the following test, I got a smaller number of btree node splits overall: sysbench --test=fileio --file-num=512 --file-total-size=5G \ --file-test-mode=seqwr --num-threads=512 \ --file-block-size=8192 --max-requests=100000 --file-io-mode=sync Before this change: * 6171 splits (average of 5 test runs) * 61.508Mb/sec of throughput (average of 5 test runs) After this change: * 6036 splits (average of 5 test runs) * 63.533Mb/sec of throughput (average of 5 test runs) An ideal test would not just have multiple threads/processes writing to a file (insertion of file extent items) but also do other operations that result in insertion of items with varied sizes, like file/directory creations, creation of links, symlinks, xattrs, etc. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28btrfs: expand btrfs_find_item() to include find_orphan_item functionalityKelley Nielsen
This is the third step in bootstrapping the btrfs_find_item interface. The function find_orphan_item(), in orphan.c, is similar to the two functions already replaced by the new interface. It uses two parameters, which are already present in the interface, and is nearly identical to the function brought in in the previous patch. Replace the two calls to find_orphan_item() with calls to btrfs_find_item(), with the defined objectid and type that was used internally by find_orphan_item(), a null path, and a null key. Add a test for a null path to btrfs_find_item, and if it passes, allocate and free the path. Finally, remove find_orphan_item(). Signed-off-by: Kelley Nielsen <kelleynnn@gmail.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28btrfs: expand btrfs_find_item() to include find_root_ref functionalityKelley Nielsen
This patch is the second step in bootstrapping the btrfs_find_item interface. The btrfs_find_root_ref() is similar to the former __inode_info(); it accepts four of its parameters, and duplicates the first half of its functionality. Replace the one former call to btrfs_find_root_ref() with a call to btrfs_find_item(), along with the defined key type that was used internally by btrfs_find_root ref, and a null found key. In btrfs_find_item(), add a test for the null key at the place where the functionality of btrfs_find_root_ref() ends; btrfs_find_item() then returns if the test passes. Finally, remove btrfs_find_root_ref(). Signed-off-by: Kelley Nielsen <kelleynnn@gmail.com> Suggested-by: Zach Brown <zab@redhat.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <clm@fb.com>