summaryrefslogtreecommitdiff
path: root/fs/btrfs/ctree.c
AgeCommit message (Collapse)AuthorFilesLines
2016-04-04btrfs: fallback to vmalloc in btrfs_compare_treeDavid Sterba1-4/+8
The allocation of node could fail if the memory is too fragmented for a given node size, practically observed with 64k. http://article.gmane.org/gmane.comp.file-systems.btrfs/54689 Reported-and-tested-by: Jean-Denis Girard <jd.girard@sysnux.pf> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-26Merge branch 'dev/gfp-flags' into for-chris-4.6David Sterba1-1/+1
2016-02-11btrfs: send: use GFP_KERNEL everywhereDavid Sterba1-1/+1
The send operation is not on the critical writeback path we don't need to use GFP_NOFS for allocations. All error paths are handled and the whole operation is restartable. Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-01Btrfs: Use (eb->start, seq) as search key for tree modification logChandan Rajendra1-17/+17
In subpagesize-blocksize a page can map multiple extent buffers and hence using (page index, seq) as the search key is incorrect. For example, searching through tree modification log tree can return an entry associated with the first extent buffer mapped by the page (if such an entry exists), when we are actually searching for entries associated with extent buffers that are mapped at position 2 or more in the page. Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-11Merge branch 'misc-cleanups-4.5' of ↵Chris Mason1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5 Signed-off-by: Chris Mason <clm@fb.com>
2016-01-07btrfs: cleanup, use enum values for btrfs_path readaDavid Sterba1-5/+4
Replace the integers by enums for better readability. The value 2 does not have any meaning since a717531942f488209dded30f6bc648167bcefa72 "Btrfs: do less aggressive btree readahead" (2009-01-22). Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-07Btrfs: use linux/sizes.h to represent constantsByongho Lee1-1/+1
We use many constants to represent size and offset value. And to make code readable we use '256 * 1024 * 1024' instead of '268435456' to represent '256MB'. However we can make far more readable with 'SZ_256MB' which is defined in the 'linux/sizes.h'. So this patch replaces 'xxx * 1024 * 1024' kind of expression with single 'SZ_xxxMB' if 'xxx' is a power of 2 then 'xxx * SZ_1M' if 'xxx' is not a power of 2. And I haven't touched to '4096' & '8192' because it's more intuitive than 'SZ_4KB' & 'SZ_8KB'. Signed-off-by: Byongho Lee <bhlee.kernel@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2015-10-22Merge branch 'cleanups/for-4.4' of ↵Chris Mason1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.4
2015-10-21btrfs: Fixed dsize and last_off declarationsAlexandru Moise1-2/+2
The return values of btrfs_item_offset_nr and btrfs_item_size_nr are of type u32. To avoid mixing signed and unsigned integers we should also declare dsize and last_off to be of type u32. Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2015-09-29Btrfs: consolidate btrfs_error() to btrfs_std_error()Anand Jain1-3/+3
btrfs_error() and btrfs_std_error() does the same thing and calls _btrfs_std_error(), so consolidate them together. And the main motivation is that btrfs_error() is closely named with btrfs_err(), one handles error action the other is to log the error, so don't closely name them. Signed-off-by: Anand Jain <anand.jain@oracle.com> Suggested-by: David Sterba <dsterba@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2015-08-09btrfs: abort transaction on btrfs_reloc_cow_block()Zhaolei1-1/+3
When btrfs_reloc_cow_block() failed in __btrfs_cow_block(), current code just return a err-value to caller, but leave new_created extent buffer exist and locked. Then subsequent code (in relocate) try to lock above eb again, and caused deadlock without any dmesg. (eb lock use wait_event(), so no lockdep message) It is hard to do recover work in __btrfs_cow_block() at this error point, but we can abort transaction to avoid deadlock and operate on unstable state.a It also helps developer to find wrong place quickly. (better than a frozen fs without any dmesg before patch) Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-03Btrfs: fix up read_tree_block to return proper errorLiu Bo1-6/+10
The return value of read_tree_block() can confuse callers as it always returns NULL for either -ENOMEM or -EIO, so it's likely that callers parse it to a wrong error, for instance, in btrfs_read_tree_root(). This fixes the above issue. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-25Merge branch 'cleanups-post-3.19' of ↵Chris Mason1-25/+28
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 Mason1-5/+4
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 Sterba1-5/+4
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>
2015-03-03Btrfs: fix off-by-one logic error in btrfs_realloc_nodeFilipe Manana1-4/+4
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 Dressler1-13/+13
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 Dressler1-12/+15
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.chandan1-1/+1
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 Manana1-2/+4
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 Mason1-8/+5
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 Mason1-13/+5
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus
2015-01-22Btrfs: change how we track dirty rootsJosef Bacik1-4/+12
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 Sterba1-1/+2
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 Sterba1-13/+4
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 Sterba1-3/+2
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 Sterba1-5/+3
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 Mason1-12/+2
into for-linus
2014-11-21Btrfs: make xattr replace operations atomicFilipe Manana1-1/+1
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 Mason1-12/+2
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 Mason1-32/+22
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 Mason1-5/+3
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
2014-10-04btrfs: fix shadow warning on cmpFabian Frederick1-4/+4
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 Sterba1-3/+2
Signed-off-by: David Sterba <dsterba@suse.cz>
2014-10-02btrfs: new define for the inline extent data startDavid Sterba1-2/+1
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 Sterba1-15/+11
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 Sterba1-7/+5
Signed-off-by: David Sterba <dsterba@suse.cz>
2014-10-02btrfs: remove parameter blocksize from read_tree_blockDavid Sterba1-7/+3
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 Sterba1-3/+3
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>
2014-09-18Btrfs: make btrfs_search_forward return with nodes unlockedFilipe Manana1-4/+7
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>
2014-09-18Btrfs: avoid unnecessary switch of path locks to blocking modeFilipe Manana1-2/+1
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>
2014-09-18Btrfs: unlock nodes earlier when inserting items in a btreeFilipe Manana1-6/+6
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>
2014-09-18btrfs: use nodesize everywhere, kill leafsizeDavid Sterba1-9/+9
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 Bacik1-10/+10
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 Bo1-0/+18
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 Manana1-1/+11
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 Bacik1-0/+4
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 Bacik1-40/+5
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 Xie1-11/+14
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 Bacik1-0/+6
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>