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path: root/fs/btrfs/ctree.c
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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>
2014-01-28btrfs: bootstrap generic btrfs_find_item interfaceKelley Nielsen
There are many btrfs functions that manually search the tree for an item. They all reimplement the same mechanism and differ in the conditions that they use to find the item. __inode_info() is one such example. Zach Brown proposed creating a new interface to take the place of these functions. This patch is the first step to creating the interface. A new function, btrfs_find_item, has been added to ctree.c and prototyped in ctree.h. It is identical to __inode_info, except that the order of the parameters has been rearranged to more closely those of similar functions elsewhere in the code (now, root and path come first, then the objectid, offset and type, and the key to be filled in last). __inode_info's callers have been set to call this new function instead, and __inode_info itself has been removed. 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>
2014-01-28Btrfs: incompatible format change to remove hole extentsJosef Bacik
Btrfs has always had these filler extent data items for holes in inodes. This has made somethings very easy, like logging hole punches and sending hole punches. However for large holey files these extent data items are pure overhead. So add an incompatible feature to no longer add hole extents to reduce the amount of metadata used by these sort of files. This has a few changes for logging and send obviously since they will need to detect holes and log/send the holes if there are any. I've tested this thoroughly with xfstests and it doesn't cause any issues with and without the incompat format set. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <clm@fb.com>
2013-11-12btrfs: Fix checkpatch.pl warning of spacing issuesDulshani Gunawardhana
Fix spacing issues detected via checkpatch.pl in accordance with the kernel style guidelines. Signed-off-by: Dulshani Gunawardhana <dulshani.gunawardhana89@gmail.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-12btrfs: Use WARN_ON()'s return value in place of WARN_ON(1)Dulshani Gunawardhana
Use WARN_ON()'s return value in place of WARN_ON(1) for cleaner source code that outputs a more descriptive warnings. Also fix the styling warning of redundant braces that came up as a result of this fix. Signed-off-by: Dulshani Gunawardhana <dulshani.gunawardhana89@gmail.com> Reviewed-by: Zach Brown <zab@redhat.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-12Btrfs: fix btrfs_prev_leaf() previous key computationFilipe David Borba Manana
If we decrement the key type, we must reset its offset to the largest possible offset (u64)-1. If we decrement the key's objectid, then we must reset the key's type and offset to their largest possible values, (u8)-1 and (u64)-1 respectively. Not doing so can make us miss an items in the tree. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-12Btrfs: kill unused code in btrfs_search_forwardLiu Bo
After commit de78b51a2852bddccd6535e9e12de65f92787a1e (btrfs: remove cache only arguments from defrag path), @blockptr is no more used. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-12Btrfs: remove unused max_key arg from btrfs_search_forwardFilipe David Borba Manana
It is not used for anything. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-12btrfs: remove unused parameter from btrfs_header_fsidRoss Kirk
Remove unused parameter, 'eb'. Unused since introduction in 5f39d397dfbe140a14edecd4e73c34ce23c4f9ee Updated to be rebased against current upstream and correct diff supplied this time! Signed-off-by: Ross Kirk <ross.kirk@gmail.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-12Btrfs: do a full search everytime in btrfs_search_old_slotJosef Bacik
While running some snashot aware defrag tests I noticed I was panicing every once and a while in key_search. This is because of the optimization that says if we find a key at slot 0 it will be at slot 0 all the way down the rest of the tree. This isn't the case for btrfs_search_old_slot since it will likely replay changes to a buffer if something has changed since we took our sequence number. So short circuit this optimization by setting prev_cmp to -1 every time we call key_search so we will do our normal binary search. With this patch I am no longer seeing the panics I was seeing before. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-11-12btrfs: drop unused parameter from btrfs_item_nrRoss Kirk
Remove unused eb parameter from btrfs_item_nr Signed-off-by: Ross Kirk <ross.kirk@gmail.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-21Btrfs: fixup error handling in btrfs_reloc_cowJosef Bacik
If we failed to actually allocate the correct size of the extent to relocate we will end up in an infinite loop because we won't return an error, we'll just move on to the next extent. So fix this up by returning an error, and then fix all the callers to return an error up the stack rather than BUG_ON()'ing. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01Btrfs: optimize key searches in btrfs_search_slotFilipe David Borba Manana
When the binary search returns 0 (exact match), the target key will necessarily be at slot 0 of all nodes below the current one, so in this case the binary search is not needed because it will always return 0, and we waste time doing it, holding node locks for longer than necessary, etc. Below follow histograms with the times spent on the current approach of doing a binary search when the previous binary search returned 0, and times for the new approach, which directly picks the first item/child node in the leaf/node. Current approach: Count: 6682 Range: 35.000 - 8370.000; Mean: 85.837; Median: 75.000; Stddev: 106.429 Percentiles: 90th: 124.000; 95th: 145.000; 99th: 206.000 35.000 - 61.080: 1235 ################ 61.080 - 106.053: 4207 ##################################################### 106.053 - 183.606: 1122 ############## 183.606 - 317.341: 111 # 317.341 - 547.959: 6 | 547.959 - 8370.000: 1 | Approach proposed by this patch: Count: 6682 Range: 6.000 - 135.000; Mean: 16.690; Median: 16.000; Stddev: 7.160 Percentiles: 90th: 23.000; 95th: 27.000; 99th: 40.000 6.000 - 8.418: 58 # 8.418 - 11.670: 1149 ######################### 11.670 - 16.046: 2418 ##################################################### 16.046 - 21.934: 2098 ############################################## 21.934 - 29.854: 744 ################ 29.854 - 40.511: 154 ### 40.511 - 54.848: 41 # 54.848 - 74.136: 5 | 74.136 - 100.087: 9 | 100.087 - 135.000: 6 | These samples were captured during a run of the btrfs tests 001, 002 and 004 in the xfstests, with a leaf/node size of 4Kb. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01Btrfs: Make btrfs_header_chunk_tree_uuid() return unsigned longGeert Uytterhoeven
Internally, btrfs_header_chunk_tree_uuid() calculates an unsigned long, but casts it to a pointer, while all callers cast it to unsigned long again. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01Btrfs: Make btrfs_header_fsid() return unsigned longGeert Uytterhoeven
Internally, btrfs_header_fsid() calculates an unsigned long, but casts it to a pointer, while all callers cast it to unsigned long again. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01Btrfs: Remove superfluous casts from u64 to unsigned long longGeert Uytterhoeven
u64 is "unsigned long long" on all architectures now, so there's no need to cast it when formatting it using the "ll" length modifier. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01Btrfs: get rid of sparse warningsStefan Behrens
make C=2 fs/btrfs/ CF=-D__CHECK_ENDIAN__ I tried to filter out the warnings for which patches have already been sent to the mailing list, pending for inclusion in btrfs-next. All these changes should be obviously safe. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01Btrfs: fix send issues related to inode number reuseJosef Bacik
If you are sending a snapshot and specifying a parent snapshot we will walk the trees and figure out where they differ and send the differences only. The way we check for differences are if the leaves aren't the same and if the keys are not the same within the leaves. So if neither leaf is the same (ie the leaf has been cow'ed from the parent snapshot) we walk each item in the send root and check it against the parent root. If the items match exactly then we don't do anything. This doesn't quite work for inode refs, since they will just have the name and the parent objectid. If you move the file from a directory and then remove that directory and re-create a directory with the same inode number as the old directory and then move that file back into that directory we will assume that nothing changed and you will get errors when you try to receive. In order to fix this we need to do extra checking to see if the inode ref really is the same or not. So do this by passing down BTRFS_COMPARE_TREE_SAME if the items match. Then if the key type is an inode ref we can do some extra checking, otherwise we just keep processing. The extra checking is to look up the generation of the directory in the parent volume and compare it to the generation of the send volume. If they match then they are the same directory and we are good to go. If they don't we have to add them to the changed refs list. This means we have to track the generation of the ref we're trying to lookup when we iterate all the refs for a particular inode. So in the case of looking for new refs we have to get the generation from the parent volume, and in the case of looking for deleted refs we have to get the generation from the send volume to compare with. There was also the issue of using a ulist to keep track of the directories we needed to check. Because we can get a deleted ref and a new ref for the same inode number the ulist won't work since it indexes based on the value. So instead just dup any directory ref we find and add it to a local list, and then process that list as normal and do away with using a ulist for this altogether. Before we would fail all of the tests in the far-progs that related to moving directories (test group 32). With this patch we now pass these tests, and all of the tests in the far-progs send testing suite. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01Btrfs: stop using GFP_ATOMIC when allocating rewind ebsJosef Bacik
There is no reason we can't just set the path to blocking and then do normal GFP_NOFS allocations for these extent buffers. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01Btrfs: deal with enomem in the rewind pathJosef Bacik
We can get ENOMEM trying to allocate dummy bufs for the rewind operation of the tree mod log. Instead of BUG_ON()'ing in this case pass up ENOMEM. I looked back through the callers and I'm pretty sure I got everybody who did BUG_ON(ret) in this path. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-09-01Btrfs: stop using GFP_ATOMIC for the tree mod log allocationsJosef Bacik
Previously we held the tree mod lock when adding stuff because we use it to check and see if we truly do want to track tree modifications. This is admirable, but GFP_ATOMIC in a critical area that is going to get hit pretty hard and often is not nice. So instead do our basic checks to see if we don't need to track modifications, and if those pass then do our allocation, and then when we go to insert the new modification check if we still care, and if we don't just free up our mod and return. Otherwise we're good to go and we can carry on. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-08-09Btrfs: fix extent buffer leak after backref walkingLiu Bo
commit 47fb091fb787420cd195e66f162737401cce023f(Btrfs: fix unlock after free on rewinded tree blocks) takes an extra increment on the reference of allocated dummy extent buffer, so now we cannot free this dummy one, and end up with extent buffer leak. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-07-02Btrfs: only do the tree_mod_log_free_eb if this is our last refJosef Bacik
There is another bug in the tree mod log stuff in that we're calling tree_mod_log_free_eb every single time a block is cow'ed. The problem with this is that if this block is shared by multiple snapshots we will call this multiple times per block, so if we go to rewind the mod log for this block we'll BUG_ON() in __tree_mod_log_rewind because we try to rewind a free twice. We only want to call tree_mod_log_free_eb if we are actually freeing the block. With this patch I no longer hit the panic in __tree_mod_log_rewind. Thanks, Cc: stable@vger.kernel.org Reviewed-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-07-02Btrfs: hold the tree mod lock in __tree_mod_log_rewindJosef Bacik
We need to hold the tree mod log lock in __tree_mod_log_rewind since we walk forward in the tree mod entries, otherwise we'll end up with random entries and trip the BUG_ON() at the front of __tree_mod_log_rewind. This fixes the panics people were seeing when running find /whatever -type f -exec btrfs fi defrag {} \; Thansk, Cc: stable@vger.kernel.org Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-07-01Btrfs: optimize reada_for_balanceJosef Bacik
This patch does two things. First we no longer explicitly read in the blocks we're trying to readahead. For things like balance_level we may never actually use the blocks so this just adds uneeded latency, and balance_level and split_node will both read in the blocks they care about explicitly so if the blocks need to be waited on it will be done there. Secondly we no longer drop the path if we do readahead, we just set the path blocking before we call reada_for_balance() and then we're good to go. Hopefully this will cut down on the number of re-searches. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-07-01Btrfs: optimize read_block_for_searchJosef Bacik
This patch does two things, first it only does one call to btrfs_buffer_uptodate() with the gen specified instead of once with 0 and then again with gen specified. The other thing is to call btrfs_read_buffer() on the buffer we've found instead of dropping it and then calling read_tree_block(). This will keep us from doing yet another radix tree lookup for a buffer we've already found. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-06-14Btrfs: check if leaf's parent exists before pushing items aroundLiu Bo
During splitting a leaf, pushing items around to hopefully get some space only works when we have a parent, ie. we have at least one sibling leaf. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-06-14Btrfs: dont do log_removal in insert_new_rootLiu Bo
As for splitting a leaf, root is just the leaf, and tree mod log does not apply on leaf, so in this case, we don't do log_removal. As for splitting a node, the old root is kept as a normal node and we have nicely put records in tree mod log for moving keys and items, so in this case we don't do that either. As above, insert_new_root can get rid of log_removal. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-06-14Btrfs: fix a commentStefan Behrens
The size parameter to btrfs_extend_item() is the number of bytes to add to the item, not the size of the item after the operation (like it is for btrfs_truncate_item(), there the size parameter is not the number of bytes to take away, but the total size of the item after truncation). Fix it in the comment. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-18Btrfs: handle running extent ops with skinny metadataJosef Bacik
Chris hit a bug where we weren't finding extent records when running extent ops. This is because we use the delayed_ref_head when running the extent op, which means we can't use the ->type checks to see if we are metadata. We also lose the level of the metadata we are working on. So to fix this we can just check the ->is_data section of the extent_op, and we can store the level of the buffer we were modifying in the extent_op. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-06btrfs: make static code static & remove dead codeEric Sandeen
Big patch, but all it does is add statics to functions which are in fact static, then remove the associated dead-code fallout. removed functions: btrfs_iref_to_path() __btrfs_lookup_delayed_deletion_item() __btrfs_search_delayed_insertion_item() __btrfs_search_delayed_deletion_item() find_eb_for_page() btrfs_find_block_group() range_straddles_pages() extent_range_uptodate() btrfs_file_extent_length() btrfs_scrub_cancel_devid() btrfs_start_transaction_lflush() btrfs_print_tree() is left because it is used for debugging. btrfs_start_transaction_lflush() and btrfs_reada_detach() are left for symmetry. ulist.c functions are left, another patch will take care of those. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-06Btrfs: separate sequence numbers for delayed ref tracking and tree mod logJan Schmidt
Sequence numbers for delayed refs have been introduced in the first version of the qgroup patch set. To solve the problem of find_all_roots on a busy file system, the tree mod log was introduced. The sequence numbers for that were simply shared between those two users. However, at one point in qgroup's quota accounting, there's a statement accessing the previous sequence number, that's still just doing (seq - 1) just as it would have to in the very first version. To satisfy that requirement, this patch makes the sequence number counter 64 bit and splits it into a major part (used for qgroup sequence number counting) and a minor part (incremented for each tree modification in the log). This enables us to go exactly one major step backwards, as required for qgroups, while still incrementing the sequence counter for tree mod log insertions to keep track of their order. Keeping them in a single variable means there's no need to change all the code dealing with comparisons of two sequence numbers. The sequence number is reset to 0 on commit (not new in this patch), which ensures we won't overflow the two 32 bit counters. Without this fix, the qgroup tracking can occasionally go wrong and WARN_ONs from the tree mod log code may happen. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-06Btrfs: fix all callers of read_tree_blockJosef Bacik
We kept leaking extent buffers when mounting a broken file system and it turns out it's because not everybody uses read_tree_block properly. You need to check and make sure the extent_buffer is uptodate before you use it. This patch fixes everybody who calls read_tree_block directly to make sure they check that it is uptodate and free it and return an error if it is not. With this we no longer leak EB's when things go horribly wrong. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-06Btrfs: remove unused argument of btrfs_extend_item()Tsutomu Itoh
Argument 'trans' is not used in btrfs_extend_item(). Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-06Btrfs: cleanup of function where fixup_low_keys() is calledTsutomu Itoh
If argument 'trans' is unnecessary in the function where fixup_low_keys() is called, 'trans' is deleted. Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-06Btrfs: remove unused argument of fixup_low_keys()Tsutomu Itoh
Argument 'trans' is not used in fixup_low_keys(). So, remove it. Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-06Btrfs: fix unlock after free on rewinded tree blocksJan Schmidt
When tree_mod_log_rewind decides to make a copy of the current tree buffer for its modifications, it subsequently freed the buffer before unlocking it. Obviously, those operations are required in reverse order. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-06Btrfs: fix accessing the root pointer in tree mod log functionsJan Schmidt
The tree mod log functions were accessing root->node->... directly, without use of btrfs_root_node() or explicit rcu locking. This could lead to an extent buffer reference being leaked and another reference being freed too early when preemtion was enabled. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>