Akinobu Mita [Mon, 18 Nov 2013 13:13:18 +0000 (22:13 +0900)]
btrfs: fix bio_size_ok() for max_sectors > 0xffff
The data type of max_sectors in queue settings is unsigned int. But
this value is stored to the local variable whose type is unsigned short
in bio_size_ok(). This can cause unexpected result when max_sectors >
0xffff.
Cc: Chris Mason <chris.mason@fusionio.com> Cc: linux-btrfs@vger.kernel.org Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Steven Rostedt [Fri, 15 Nov 2013 03:57:29 +0000 (22:57 -0500)]
btrfs: Use trace condition for get_extent tracepoint
Doing an if statement to test some condition to know if we should
trigger a tracepoint is pointless when tracing is disabled. This just
adds overhead and wastes a branch prediction. This is why the
TRACE_EVENT_CONDITION() was created. It places the check inside the jump
label so that the branch does not happen unless tracing is enabled.
That is, instead of doing:
if (em)
trace_btrfs_get_extent(root, em);
Which is basically this:
if (em)
if (static_key(trace_btrfs_get_extent)) {
Using a TRACE_EVENT_CONDITION() we can just do:
trace_btrfs_get_extent(root, em);
And the condition trace event will do:
if (static_key(trace_btrfs_get_extent)) {
if (em) {
...
The static key is a non conditional jump (or nop) that is faster than
having to check if em is NULL or not.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Miao Xie [Thu, 14 Nov 2013 09:33:21 +0000 (17:33 +0800)]
Btrfs: fix list delete warning when removing ordered root from the list
Commit b02441999efcc6152b87cd58e7970bb7843f76cf "Btrfs: don't wait for
the completion of all the ordered extents" introduced a bug that broke
the ordered root list:
WARNING: CPU: 1 PID: 7119 at lib/list_debug.c:59 __list_del_entry+0x5a/0x98()
It is because we forgot to return the roots in the splice list to the
ordered list of the fs. Fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Stefan Behrens [Wed, 13 Nov 2013 16:19:08 +0000 (17:19 +0100)]
Btrfs: print bytenr instead of page pointer in check-int
The page pointer information was useless. The bytenr is what you
want when you search for submitted write bios.
Additionally, a new bit in the print mask is added that allows
to selectively enable the check-int submit_bio verbose mode. Before,
the global verbose mode had to be enabled leading to many million
useless lines in the kernel log.
And a comment is added that explains that LOG_BUF_SHIFT needs to
be set to a really high value.
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>
Wang Shilong [Tue, 12 Nov 2013 11:32:04 +0000 (19:32 +0800)]
Btrfs: remove dead codes from ctree.h
These two functions are only stated but undefined.
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: don't wait for ordered data outside desired range
In btrfs_wait_ordered_range(), if we found an extent to the left
of the start of our desired wait range and the last byte of that
extent is 1 less than the desired range's start, we would would
wait for the IO completion of that extent unnecessarily.
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>
It's because that we don't do the right thing when checking if it's ok to
tell lockdep that we're trying to release the rwsem.
If the trans handle's type is TRANS_ATTACH, we won't acquire the freeze rwsem, but
as TRANS_ATTACH fits the check (trans < TRANS_JOIN_NOLOCK), we'll release the freeze
rwsem, which makes lockdep complains a lot.
Reported-by: Ma Jianpeng <majianpeng@gmail.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Liu Bo [Tue, 5 Nov 2013 03:45:53 +0000 (11:45 +0800)]
Btrfs: avoid heavy operations in btrfs_commit_super
The 'git blame' history shows that, the old transaction commit code has to do
twice to ensure roots are updated and we have to flush metadata and super block
manually, however, right now all of these can be handled well inside
the transaction commit code without extra efforts.
And the error handling part remains same with the current code, -- 'return to
caller once we get error'.
This saves us a transaction commit and a flush of super block, which are both
heavy operations according to ftrace output analysis.
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>
Ilya Dryomov [Sun, 3 Nov 2013 17:06:40 +0000 (19:06 +0200)]
Btrfs: fix __btrfs_start_workers retval
__btrfs_start_workers returns 0 in case it raced with
btrfs_stop_workers and lost the race. This is wrong because worker in
this case is not allowed to start and is in fact destroyed. Return
-EINVAL instead.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Ilya Dryomov [Sun, 3 Nov 2013 17:06:38 +0000 (19:06 +0200)]
Btrfs: do not inc uncorrectable_errors counter on ro scrubs
Currently if we discover an error when scrubbing in ro mode we a)
blindly increment the uncorrectable_errors counter, and b) spam the
dmesg with the 'unable to fixup (regular) error at ...' message, even
though a) we haven't tried to determine if the error is correctable or
not, and b) we haven't tried to fixup anything. Fix this.
Cc: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Wed, 13 Nov 2013 01:54:09 +0000 (20:54 -0500)]
Btrfs: only drop modified extents if we logged the whole inode
If we fsync, seek and write, rename and then fsync again we will lose the
modified hole extent because the rename will drop all of the modified extents
since we didn't do the fast search. We need to only drop the modified extents
if we didn't do the fast search and we were logging the entire inode as we don't
need them anymore, otherwise this is being premature. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Tue, 12 Nov 2013 21:25:58 +0000 (16:25 -0500)]
Btrfs: make sure to copy everything if we rename
If we rename a file that is already in the log and we fsync again we will lose
the new name. This is because we just log the inode update and not the new ref.
To fix this we just need to check if we are logging the new name of the inode
and copy all the metadata instead of just updating the inode itself. With this
patch my testcase now passes. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Chris Mason [Fri, 15 Nov 2013 11:14:55 +0000 (12:14 +0100)]
btrfs: fix empty_zero_page misusage
Heiko Carstens noticed that btrfs was using empty_zero_page
incorrectly. He explained:
The definition of empty_zero_page is architecture specific. It
is (currently) either a character array, an unsigned long
containing the address of the empty_zero_page, or even worse
only the address of the struct page belonging to the
empty_zero_page.
This commit changes btrfs to use a for-loop instead. On x86
the resulting .ko is smaller, and we're no longer worrying about
how each arch builds its zeros.
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Miao Xie [Mon, 4 Nov 2013 15:13:26 +0000 (23:13 +0800)]
Btrfs: rename btrfs_start_all_delalloc_inodes
rename the function -- btrfs_start_all_delalloc_inodes(), and make its
name be compatible to btrfs_wait_ordered_roots(), since they are always
used at the same place.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Miao Xie [Mon, 4 Nov 2013 15:13:25 +0000 (23:13 +0800)]
Btrfs: don't wait for the completion of all the ordered extents
It is very likely that there are lots of ordered extents in the filesytem,
if we wait for the completion of all of them when we want to reclaim some
space for the metadata space reservation, we would be blocked for a long
time. The performance would drop down suddenly for a long time.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Miao Xie [Mon, 4 Nov 2013 15:13:24 +0000 (23:13 +0800)]
Btrfs: don't wait for all the async delalloc when shrinking delalloc
It was very likely that there were lots of async delalloc pages in the
filesystem, if we waited until all the pages were flushed, we would be
blocked for a long time, and the performance would also drop down.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Miao Xie [Mon, 4 Nov 2013 15:13:23 +0000 (23:13 +0800)]
Btrfs: fix the confusion between delalloc bytes and metadata bytes
In shrink_delalloc(), what we need reclaim is the metadata space, so
flushing pages by to_reclaim is not reasonable, it is very likely that
the pages we flush are not enough. And then we had to invoke the flush
function for several times, at the worst, we need call flush_space for
several times. It wasted time.
We improve this problem by converting the metadata space size we need
reserve to the delalloc bytes, By this way, we can flush the pages
by a reasonable number.
(Now we use a fixed number to do conversion, it is not flexible, maybe
we can find a good way to improve it in the future.)
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Miao Xie [Mon, 4 Nov 2013 15:13:22 +0000 (23:13 +0800)]
Btrfs: pick up the code for the item number calculation in flush_space()
This patch picked up the code that was used to calculate the number of
the items for which we need reserve space, and we will use it in the next
patch.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Wang Shilong [Fri, 11 Oct 2013 18:11:12 +0000 (02:11 +0800)]
Btrfs: avoid unnecessary scrub workers allocation
We only allocate scrub workers if we pass all the necessary
checks, for example, there are no operation in progress.
Besides, move mutex lock protection outside of scrub_workers_get()
/scrub_workers_put().
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Thu, 31 Oct 2013 20:49:02 +0000 (16:49 -0400)]
Btrfs: check file extent type before anything else
I hit this problem with my no holes patch and it made me realize what the
problem was for bz 60834. If the first item in the leaf is an inline extent and
we try to read anything starting from disk_bytenr onward we will read off the
end of the leaf. So we need to check to see what it's type is, and if it's not
REG we can just break out. This should fix this problem. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Rashika [Thu, 31 Oct 2013 11:20:42 +0000 (16:50 +0530)]
btrfs: Remove useless variable in write_ctree_super()
The function write_ctree_super() in disk-io.c uses variable ret to return
the result of function write_all_supers(). Since, this variable serves
no purpose, hence the patch removes it and returns the call of the
called function.
Reviewed-by: Zach Brown <zab@redhat.com> Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Replace kmalloc(size * nr, ) with kmalloc_array(nr, size), thus making
it easier to check is that the calculation doesn't wrap or return a smaller allocation
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>
btrfs: Use WARN_ON()'s return value in place of WARN_ON(1)
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>
Rashika [Wed, 30 Oct 2013 21:15:20 +0000 (02:45 +0530)]
btrfs: Add helper function for free_root_pointers()
The function free_root_pointers() in disk-io.h contains redundant code.
Therefore, this patch adds a helper function free_root_extent_buffers()
to free_root_pointers() to eliminate redundancy.
Reviewed-by: Zach Brown <zab@redhat.com> Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
It turns out to be that balance operation will bump root's @last_snapshot,
which enables snapshot-aware defrag path, and backref walking stuff will
find data reloc tree as refs' parent, and hit the BUG_ON() during COW.
As data reloc tree's data is just for relocation purpose, and will be deleted right
after relocation is done, it's unnecessary to walk those refs belonged to data reloc
tree, it'd be better to skip them.
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>
Btrfs: log recovery, don't unlink inode always on error
If we get any error while doing a dir index/item lookup in the
log tree, we were always unlinking the corresponding inode in
the subvolume. It makes sense to unlink only if the lookup failed
to find the dir index/item, which corresponds to NULL or -ENOENT,
and not when other errors happen (like a transient -ENOMEM or -EIO).
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>
Btrfs: fix csum search offset/length calculation in log tree
We were setting the csums search offset and length to the right values if
the extent is compressed, but later on right before doing the csums lookup
we were overriding these two parameters regardless of compression being
set or not for the extent.
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>
We were ignoring the name component of the dir_item. Both the
name and data must fit within BTRFS_MAX_XATTR_SIZE(root).
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>
Wang Shilong [Fri, 25 Oct 2013 11:12:02 +0000 (19:12 +0800)]
Btrfs: remove scrub_super_lock holding in btrfs_sync_log()
Originally, we introduced scrub_super_lock to synchronize
tree log code with scrubbing super.
However we can replace scrub_super_lock with device_list_mutex,
because writing super will hold this mutex, this will reduce an extra
lock holding when writing supers in sync log code.
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Wang Shilong [Fri, 25 Oct 2013 10:52:08 +0000 (18:52 +0800)]
Btrfs: use 'u64' rather than 'int' to get extent's generation
We define a 'int' to get extent's generation by mistake,fix it.
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Miao Xie [Fri, 25 Oct 2013 09:33:36 +0000 (17:33 +0800)]
Btrfs: fix the free space write out failure when there is no data space
After running space balance on a new fs, the fs check program outputed the
following warning message:
free space inode generation (0) did not match free space cache generation (20)
It was because there was no data space after the space balance, and the free
space write out task didn't try to allocate a new data chunk for the free space
inode when doing the reservation. So the data space reservation failed, and in
order to tell the free space loader that this free space inode could not be
trusted, the generation of the free space inode wasn't updated. Then the check
program found this problem and outputed the above message.
But in fact, it is safe that we try to allocate a new data chunk when we find
the data space is not enough. The patch fixes the above problem by this way.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Thu, 31 Oct 2013 14:07:19 +0000 (10:07 -0400)]
Btrfs: stop committing the transaction so much during relocate
I noticed with my horrible snapshot excercisor that we were taking forever to
relocate the larger the file system got. This appeared to be because we were
committing the transaction _constantly_. There were a few places where we do
braindead things with metadata reservation, like start a transaction and then
try to refill the block rsv, which not only keeps us from committing a
transaction during the enospc stuff, but keeps us from doing some of the harder
flushing work which will make us more likely to need to commit the transaction.
We also were checking the block rsv and committing the transaction if the block
rsv was below a certain threshold, but we were doing this in a place where we
don't actually keep anything in the block rsv so this was always ending up false
so we always committed the transaction in this case. I tested this to make sure
it didn't break anything, but it takes about 10 hours to get the box to this
state so I don't know how much of an impact it will really make. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Mon, 28 Oct 2013 19:03:41 +0000 (15:03 -0400)]
Btrfs: make sure the delalloc workers actually flush compressed writes
When using delalloc workers in a non-waiting way (like for enospc handling) we
can end up not actually waiting for the dirty pages to be started if we have
compression. We need to add an extra filemap flush to make sure any async
extents that have started are actually moved along before returning. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Mon, 28 Oct 2013 13:13:25 +0000 (09:13 -0400)]
Btrfs: take ordered root lock when removing ordered operations inode
A user reported a list corruption warning from btrfs_remove_ordered_extent, it
is because we aren't taking the ordered_root_lock when we remove the inode from
the ordered operations list. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Fri, 25 Oct 2013 20:55:08 +0000 (16:55 -0400)]
Btrfs: don't abort transaction in run_delalloc_nocow
This is just the write path, the only reason we start a transaction is so we can
check cross references, we don't make any actual changes, so there is no reason
to abort the transaction if we fail. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Fri, 25 Oct 2013 20:19:08 +0000 (16:19 -0400)]
Btrfs: do not bug_on if we try to cow a free space cache inode
We can just return an error and we'll bail out properly. We still want to catch
this case to make sure we don't have a bug somewhere, so just warn if this pops
up. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Fri, 25 Oct 2013 20:13:35 +0000 (16:13 -0400)]
Btrfs: return an error from btrfs_wait_ordered_range
I noticed that if the free space cache has an error writing out it's data it
won't actually error out, it will just carry on. This is because it doesn't
check the return value of btrfs_wait_ordered_range, which didn't actually return
anything. So fix this in order to keep us from making free space cache look
valid when it really isnt. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Fri, 25 Oct 2013 15:36:01 +0000 (11:36 -0400)]
Btrfs: stop using vfs_read in send
Apparently we don't actually close the files until we return to userspace, so
stop using vfs_read in send. This is actually better for us since we can avoid
all the extra logic of holding the file we're sending open and making sure to
clean it up. This will fix people who have been hitting too many files open
errors when trying to send. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Stefan Behrens [Mon, 21 Oct 2013 16:46:58 +0000 (18:46 +0200)]
Btrfs: check_int, remove warning for mixed-mode
In mixed-mode, when a data-block was later reused for metadata, a
warning was printed. This condition is now filtered out and the
warning is eliminated in this case.
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>
Stefan Behrens [Mon, 21 Oct 2013 12:18:17 +0000 (14:18 +0200)]
Btrfs: fix check_int 'leaf item out of bounce' regression
Yet another cleanup patch broke code for which no xfstest exists.
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>
Btrfs: optimize extent item search in run_delayed_extent_op
Instead of doing another extent tree search if the first search failed
to find a metadata item, check if the previous item in the leaf is an
extent item and use it if it is, otherwise do the second tree search
for an extent item.
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>
Zach Brown [Wed, 16 Oct 2013 19:10:33 +0000 (12:10 -0700)]
btrfs: remove move_pages()
move_pages() has an inefficient backwards byte copy of regions of two
different pages. They're different pages so the regions won't overlap
and it could use memcpy().
At that point, though, move_pages() would be a slightly dimmer
re-implementation of copy_pages() that lacked the test for overlapping
page regions.
So remove move_pages() and just call copy_pages().
Signed-off-by: Zach Brown <zab@redhat.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
When a directory has a default ACL and a subdirectory is created
under that directory, btrfs_init_acl() is called when the
subdirectory's inode is created to initialize the inode's ACL
(inherited from the parent directory) but it was clearing the ACL
from the inode after setting it if posix_acl_create() returned
success, instead of clearing it only if it returned an error.
Reported-by: Giuseppe Fierro <giuseppe@fierro.org> 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>
Stefan Behrens [Tue, 15 Oct 2013 18:08:15 +0000 (20:08 +0200)]
Btrfs: Don't allocate inode that is already in use
Due to an off-by-one error, it is possible to reproduce a bug
when the inode cache is used.
The same inode number is assigned twice, the second time this
leads to an EEXIST in btrfs_insert_empty_items().
The issue can happen when a file is removed right after a subvolume
is created and then a new inode number is created before the
inodes in free_inode_pinned are processed.
unlink() calls btrfs_return_ino() which calls start_caching() in this
case which adds [highest_ino + 1, BTRFS_LAST_FREE_OBJECTID] by
searching for the highest inode (which already cannot find the
unlinked one anymore in btrfs_find_free_objectid()). So if this
unlinked inode's number is equal to the highest_ino + 1 (or >= this value
instead of > this value which was the off-by-one error), we mustn't add
the inode number to free_ino_pinned (caching_thread() does it right).
In this case we need to try directly to add the number to the inode_cache
which will fail in this case.
When this inode number is allocated while it is still in free_ino_pinned,
it is allocated and still added to the free inode cache when the
pinned inodes are processed, thus one of the following inode number
allocations will get an inode that is already in use and fail with EEXIST
in btrfs_insert_empty_items().
One example which was created with the reproducer below:
Create a snapshot, work in the newly created snapshot for the rest.
In unlink(inode 34284) call btrfs_return_ino() which calls start_caching().
start_caching() calls add_free_space [34284, 18446744073709517077].
In btrfs_return_ino(), call start_caching pinned [34284, 1] which is wrong.
mkdir() call btrfs_find_ino_for_alloc() which returns the number 34284.
btrfs_unpin_free_ino calls add_free_space [34284, 1].
mkdir() call btrfs_find_ino_for_alloc() which returns the number 34284.
EEXIST when the new inode is inserted.
One possible reproducer is this one:
#!/bin/sh
# preparation
TEST_DEV=/dev/sdc1
TEST_MNT=/mnt
umount ${TEST_MNT} 2>/dev/null || true
mkfs.btrfs -f ${TEST_DEV}
mount ${TEST_DEV} ${TEST_MNT} -o \
rw,relatime,compress=lzo,space_cache,inode_cache
btrfs subv create ${TEST_MNT}/s1
for i in `seq 34027`; do touch ${TEST_MNT}/s1/${i}; done
btrfs subv snap ${TEST_MNT}/s1 ${TEST_MNT}/s2
FILENAME=`find ${TEST_MNT}/s1/ -inum 4085 | sed 's|^.*/\([^/]*\)$|\1|'`
rm ${TEST_MNT}/s2/$FILENAME
touch ${TEST_MNT}/s2/$FILENAME
# the following steps can be repeated to reproduce the issue again and again
[ -e ${TEST_MNT}/s3 ] && btrfs subv del ${TEST_MNT}/s3
btrfs subv snap ${TEST_MNT}/s2 ${TEST_MNT}/s3
rm ${TEST_MNT}/s3/$FILENAME
touch ${TEST_MNT}/s3/$FILENAME
ls -alFi ${TEST_MNT}/s?/$FILENAME
touch ${TEST_MNT}/s3/_1 || logger FAILED
ls -alFi ${TEST_MNT}/s?/_1
touch ${TEST_MNT}/s3/_2 || logger FAILED
ls -alFi ${TEST_MNT}/s?/_2
touch ${TEST_MNT}/s3/__1 || logger FAILED
ls -alFi ${TEST_MNT}/s?/__1
touch ${TEST_MNT}/s3/__2 || logger FAILED
ls -alFi ${TEST_MNT}/s?/__2
# if the above is not enough, add the following loop:
for i in `seq 3 9`; do touch ${TEST_MNT}/s3/__${i} || logger FAILED; done
#for i in `seq 3 34027`; do touch ${TEST_MNT}/s3/__${i} || logger FAILED; done
# one of the touch(1) calls in s3 fail due to EEXIST because the inode is
# already in use that btrfs_find_ino_for_alloc() returns.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> 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>
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>
Avoid repeated tree searches by processing all inode ref items in
a leaf at once instead of processing one at a time, followed by a
path release and a tree search for a key with a decremented offset.
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>
Geyslan G. Bem [Mon, 14 Oct 2013 15:18:25 +0000 (12:18 -0300)]
btrfs: simplify kmalloc+copy_from_user to memdup_user
Use memdup_user rather than duplicating its implementation
This is a little bit restricted to reduce false positives
The semantic patch that makes this report is available
in scripts/coccinelle/api/memdup_user.cocci.
More information about semantic patching is available at
http://coccinelle.lip6.fr/
Signed-off-by: Geyslan G. Bem <geyslan@gmail.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: don't leak delayed node on path allocation failure
If the path allocation failed, we would return without decrementing
the reference count in the delayed node we got before, resulting
in a leak.
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>
Stefan Behrens [Fri, 11 Oct 2013 15:14:58 +0000 (17:14 +0200)]
Btrfs: Wait for uuid-tree rebuild task on remount read-only
If the user remounts the filesystem read-only while the uuid-tree
scan and rebuild task is still running (this happens once after the
filesystem was mounted with an old kernel, or when forced with the
mount options), the remount should wait on the tasks completion
before setting the filesystem read-only. Otherwise the background
task continues to write to the filesystem which is apparently not
what users expect.
The reproducer:
TEST_DEV=/dev/sdzzzzz1
TEST_MNT=/mnt
mkfs.btrfs -f $TEST_DEV
mount $TEST_DEV $TEST_MNT
for i in `seq 50000`; do btrfs subvolume create ${TEST_MNT}/$i; done
umount $TEST_MNT
mount $TEST_DEV $TEST_MNT -o rescan_uuid_tree
sleep 1
ps -elf | fgrep '[btrfs-uuid]' | grep -v grep
mount $TEST_DEV $TEST_MNT -o ro,remount
ps -elf | fgrep '[btrfs-uuid]' | grep -v grep
sleep 1
umount $TEST_MNT
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>
Stefan Behrens [Fri, 11 Oct 2013 13:20:42 +0000 (15:20 +0200)]
Btrfs: init device stats for new devices
Device stats are only initialized (read from tree items) on mount.
Trying to read device stats after adding or replacing new devices will
return errors.
btrfs_init_new_device() and btrfs_init_dev_replace_tgtdev() are the two
functions that allocate and initialize new btrfs_device structures after
a filesystem is mounted. They set the device stats to zero by using
kzalloc() which is correct for new devices. The only missing thing was
to declare these stats as being valid (device->dev_stats_valid = 1) and
this patch adds this missing code.
Reported-by: Ondrej Kunc <kunc88@gmail.com> 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>
Liu Bo [Fri, 11 Oct 2013 08:30:23 +0000 (16:30 +0800)]
Btrfs: fixup error path in __btrfs_inc_extent_ref
When we fail to add a reference after a non-inline insertion by some reasons,
eg. ENOSPC, we'll abort the transaction, but we don't return this error to
the caller who has to walk around again to find something wrong, that's
unnecessary.
Also fixup other error paths to keep it simple.
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>
Ilya Dryomov [Thu, 10 Oct 2013 17:40:21 +0000 (20:40 +0300)]
Btrfs: disallow 'btrfs {balance,replace} cancel' on ro mounts
For both balance and replace, cancelling involves changing the on-disk
state and committing a transaction, which is not a good thing to do on
read-only filesystems.
Cc: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Ilya Dryomov [Thu, 10 Oct 2013 17:37:29 +0000 (20:37 +0300)]
Btrfs: nuke a bogus rw_devices decrement in __btrfs_close_devices
On mount failures, __btrfs_close_devices can be called well before
dev-replace state is read and ->is_tgtdev_for_dev_replace is set. This
leads to a bogus decrement of ->rw_devices and sets off a WARN_ON in
__btrfs_close_devices if replace target device happens to be on the
lists and we fail early in the mount sequence. Fix this by checking
the devid instead of ->is_tgtdev_for_dev_replace before the decrement:
for replace targets devid is always equal to BTRFS_DEV_REPLACE_DEVID.
Cc: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Geyslan G. Bem [Fri, 11 Oct 2013 18:35:45 +0000 (15:35 -0300)]
btrfs: Fix memory leakage in the tree-log.c
In add_inode_ref() function:
Initializes local pointers.
Reduces the logical condition with the __add_inode_ref() return
value by using only one 'goto out'.
Centralizes the exiting, ensuring the freeing of all used memory.
Signed-off-by: Geyslan G. Bem <geyslan@gmail.com> Reviewed-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: remove unnecessary key copy when logging inode
The btrfs_insert_empty_item() function doesn't modify its
key argument.
Signed-off-by: Filipe David Borba Manana <fdmanana@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>
Btrfs: Simplify the logic in alloc_extent_buffer() for existing extent buffer case
alloc_extent_buffer() uses radix_tree_lookup() when radix_tree_insert()
fails with EEXIST. That part of the code is very similar to the code in
find_extent_buffer(). This patch replaces radix_tree_lookup() and
surrounding code in alloc_extent_buffer() with find_extent_buffer().
Note that radix_tree_lookup() does not need to be protected by
tree->buffer_lock. It is protected by eb->refs.
While at it, this patch
- changes the other usage of radix_tree_lookup() in alloc_extent_buffer()
with find_extent_buffer() to reduce redundancy.
- removes the unused argument 'len' to find_extent_buffer().
Signed-Off-by: Chandra Seetharaman <sekharan@us.ibm.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>
Josef Bacik [Fri, 18 Oct 2013 15:44:46 +0000 (11:44 -0400)]
Btrfs: fix up seek_hole/seek_data handling
Whoever wrote this was braindead. Also it doesn't work right if you have
VACANCY's since we assumed you would only have that at the end of the file,
which won't be the case in the near future. I tested this with generic/285 and
generic/286 as well as the btrfs tests that use fssum since it uses
seek_hole/seek_data to verify things are ok. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Tue, 15 Oct 2013 13:36:40 +0000 (09:36 -0400)]
Btrfs: add an assert to btrfs_lookup_csums_range for alignment
I was hitting weird issues when trying to remove hole extents and it turned out
it was because I was sending non-aligned offsets down to
btrfs_lookup_csums_range. So add an assert for this in case somebody trips over
this in the future. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Mon, 14 Oct 2013 21:23:08 +0000 (17:23 -0400)]
Btrfs: fix hole check in log_one_extent
I added an assert to make sure we were looking up aligned offsets for csums and
I tripped it when running xfstests. This is because log_one_extent was checking
if block_start == 0 for a hole instead of EXTENT_MAP_HOLE. This worked out fine
in practice it seems, but it adds a lot of extra work that is uneeded. With
this fix I'm no longer tripping my assert. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Mon, 14 Oct 2013 16:08:38 +0000 (12:08 -0400)]
Btrfs: handle a missing extent for the first file extent
While trying to kill our hole extents I noticed I was seeing problems where we
seek into a file and then start writing and then try to fiemap that file later.
This is because we search for offset 0, don't find anything and so back up one
slot, which puts us at the inode ref or something like that, which means we goto
not_found and create an extent map for our entire search area. This isn't quite
what we want, we want to move forward one slot and see if there is an extent
there so we can limit our hole extent. This patch fixes this problem, I will
add a testcase for this as well. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Wed, 16 Oct 2013 17:53:28 +0000 (13:53 -0400)]
Btrfs: stop all workers after we free block groups
Stefan was hitting a panic in the async worker stuff because we had outstanding
read bios while we were stopping the worker threads. You could reproduce this
easily if you mount -o nospace_cache and ran generic/273. This is because the
caching thread stuff is still going and we were stopping all the worker threads.
We need to stop the workers after this work is done, and the free block groups
code will wait for all the caching threads to stop first so we don't run into
this problem. With this patch we no longer panic. Thanks,
Cc: stable@vger.kernel.org Reported-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Fri, 11 Oct 2013 18:44:09 +0000 (14:44 -0400)]
Btrfs: add tests for btrfs_get_extent
I'm going to be removing hole extents in the near future so I wanted to make a
sanity test for btrfs_get_extent to make sure I don't break anything in the
meantime. This patch just puts btrfs_get_extent through its paces by giving it
a completely unreasonable mapping to look at and make sure it is giving us back
maps that make sense. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Wed, 9 Oct 2013 16:00:56 +0000 (12:00 -0400)]
Btrfs: add tests for find_lock_delalloc_range
So both Liu and I made huge messes of find_lock_delalloc_range trying to fix
stuff, me first by fixing extent size, then him by fixing something I broke and
then me again telling him to fix it a different way. So this is obviously a
candidate for some testing. This patch adds a pseudo fs so we can allocate fake
inodes for tests that need an inode or pages. Then it addes a bunch of tests to
make sure find_lock_delalloc_range is acting the way it is supposed to. With
this patch and all of our previous patches to find_lock_delalloc_range I am sure
it is working as expected now. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Mon, 7 Oct 2013 19:21:08 +0000 (15:21 -0400)]
Btrfs: free reserved space on error in a few places
While trying to track down a reserved space leak I noticed a few places where we
won't properly clean up reserved space if we have an error, this patch fixes
those up. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Mon, 7 Oct 2013 19:18:52 +0000 (15:18 -0400)]
Btrfs: fixup reserved trace points
In trying to track down where we were leaking reserved space I noticed our
reserve extent tracepoints are a little off. First we were saying that the
reserved space had been alloced in btrfs_reserve_extent, which isn't the case,
this needs to be triggered when we actually allocate the space when we run the
delayed ref. We were also missing a few places where we should have been
tracing the btrfs_reserve_extent_free tracepoint. With these in place I was
able to put together where we were leaking reserved space. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Mon, 7 Oct 2013 19:14:44 +0000 (15:14 -0400)]
Btrfs: free up block groups after everything
If we abort a transaction we will do the tree log cleanup at unmount, but this
happens after we free up the block groups. This makes all the leak detection
warnings go off because we think we've leaked space but in reality we just
haven't cleaned it up yet. So instead do the block group cleanup stuff after
free'ing the fs roots so we don't get these warnings. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Mon, 7 Oct 2013 19:11:00 +0000 (15:11 -0400)]
Btrfs: cleanup reserved space when freeing tree log on error
On error we will wait and free the tree log at unmount without a transaction.
This means that the actual freeing of the blocks doesn't happen which means we
complain about space leaks on unmount. So to fix this just skip the transaction
specific cleanup part of the tree log free'ing if we don't have a transaction
and that way we can free up our reserved space and our counters stay happy.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Mon, 7 Oct 2013 14:45:07 +0000 (10:45 -0400)]
Btrfs: do not free the dirty bytes from the trans block rsv on cleanup
The transactions should be cleaning up their reservations on failure, this just
causes us to have warnings on unmount because we go negative by free'ing
reservations that have already been free'ed. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: fix memory leaks on transaction commit failure
Structures of the types tree_mod_elem and qgroup_update are allocated
during transaction commit but were not being released if the call to
btrfs_run_delayed_items() returned an error.
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>
Ilya Dryomov [Mon, 7 Oct 2013 10:42:57 +0000 (13:42 +0300)]
Btrfs: fix the dev-replace suspend sequence
Replace progresses strictly from lower to higher offsets, and the
progress is tracked in chunks, by storing the physical offset of the
dev_extent which is being copied in the cursor_left field of
btrfs_dev_replace_item. When we are done copying the chunk,
left_cursor is updated to point one byte past the dev_extent, so that
on resume we can skip the dev_extents that have already been copied.
There is a major bug (which goes all the way back to the inception of
dev-replace in 3.8) in the way left_cursor is bumped: the bump is done
unconditionally, without any regard to the scrub_chunk return value.
On suspend (and also on any kind of error) scrub_chunk returns early,
i.e. without completing the copy. This leads to us skipping the chunk
that hasn't been fully copied yet when resuming.
Fix this by doing the cursor_left update only if scrub_chunk ret is 0.
(On suspend scrub_chunk returns with -ECANCELED, so this fix covers
both suspend and error cases.)
Cc: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Currently the hash value used for adding an inode to the VFS's inode
hash table consists of the plain inode number, which is a 64 bits
integer. This results in hash table buckets (hlist_head lists) with
too many elements for at least 2 important scenarios:
1) When we have many subvolumes. Each subvolume has its own btree
where its files and directories are added to, and each has its
own objectid (inode number) namespace. This means that if we have
N subvolumes, and all have inode number X associated to a file or
directory, the corresponding inodes all map to the same hash table
entry, resulting in a bucket (hlist_head list) with N elements;
2) On 32 bits machines. Th VFS hash values are unsigned longs, which
are 32 bits wide on 32 bits machines, and the inode (objectid)
numbers are 64 bits unsigned integers. We simply cast the inode
numbers to hash values, which means that for all inodes with the
same 32 bits lower half, the same hash bucket is used for all of
them. For example, all inodes with a number (objectid) between
0x0000_0000_ffff_ffff and 0xffff_ffff_ffff_ffff will end up in
the same hash table bucket.
This change ensures the inode's hash value depends both on the
objectid (inode number) and its subvolume's (btree root) objectid.
For 32 bits machines, this change gives better entropy by making
the hash value depend on both the upper and lower 32 bits of the
64 bits hash previously computed.
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>
Btrfs: remove unnecessary tree search when logging inode
In tree-log.c:btrfs_log_inode(), we keep calling btrfs_search_forward()
until it returns a key whose objectid is higher than our inode or until
the key's type is higher than our maximum allowed type.
At the end of the loop, we increment our mininum search key's objectid
and type regardless of our desired target objectid and maximum desired
type, which causes another loop iteration that will call again
btrfs_search_forward() just to figure out we've gone beyond our maximum
key and exit the loop. Therefore while incrementing our minimum key,
don't do it blindly and exit the loop immiediately if the next search
key's objectid or type is beyond what we seek.
Also after incrementing the type, set the key's offset to 0, which was
missing and could make us loose some of the inode's items.
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>
Btrfs: remove unused max_key arg from btrfs_search_forward
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>
Btrfs: improve jitter performance of the sequential buffered write
The performance was slowed down sometimes when we ran sysbench to measure
the performance of the sequential buffered write by 2 or more threads.
It was because the write order of the test threads might be confused
by the task scheduler, and the coming write would be beyond the end of
the file, in this case, we need insert dummy file extents and create
a hole for the area we skip. But in order to avoid the ongoing ordered
extents which are in the area, we need wait for them. Unfortunately,
the current code doesn't check if there are ordered extents in the area
or not, try to find and flush the dirty pages directly, but in fact,
there is no dirty page in that area, this step of the current code is
unnecessary, and just wastes time. Sometimes, it would increase
the contention of some locks, and makes the performance slow down suddenly.
So we remove the ordered extent flush function before the check, and flush
the dirty pages and wait for the ordered extents only when we find them.
According to my test, we got 1-2 times of the performance regression when
we ran the test by 10 times before applying this patch. After applying
this patch, the regression went away.
Test Environment:
CPU: 1CPU * 4Cores
Memory: 6GB
Partition: 20GB
Test Command:
# sysbench --test=fileio --file-total-size=16G --file-test-mode=seqwr \
> --num-threads=512 --file-block-size=16384 --max-time=60 --max-requests=0 run
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Btrfs: fix BUG_ON() casued by the reserved space migration
When we did space balance and snapshot creation at the same time, we might
meet the following oops:
kernel BUG at fs/btrfs/inode.c:3038!
[SNIP]
Call Trace:
[<ffffffffa0411ec7>] btrfs_orphan_cleanup+0x293/0x407 [btrfs]
[<ffffffffa042dc45>] btrfs_mksubvol.isra.28+0x259/0x373 [btrfs]
[<ffffffffa042de85>] btrfs_ioctl_snap_create_transid+0x126/0x156 [btrfs]
[<ffffffffa042dff1>] btrfs_ioctl_snap_create_v2+0xd0/0x121 [btrfs]
[<ffffffffa0430b2c>] btrfs_ioctl+0x414/0x1854 [btrfs]
[<ffffffff813b60b7>] ? __do_page_fault+0x305/0x379
[<ffffffff811215a9>] vfs_ioctl+0x1d/0x39
[<ffffffff81121d7c>] do_vfs_ioctl+0x32d/0x3e2
[<ffffffff81057fe7>] ? finish_task_switch+0x80/0xb8
[<ffffffff81121e88>] SyS_ioctl+0x57/0x83
[<ffffffff813b39ff>] ? do_device_not_available+0x12/0x14
[<ffffffff813b99c2>] system_call_fastpath+0x16/0x1b
[SNIP]
RIP [<ffffffffa040da40>] btrfs_orphan_add+0xc3/0x126 [btrfs]
The reason of the problem is that the relocation root creation stole
the reserved space, which was reserved for orphan item deletion.
There are several ways to fix this problem, one is to increasing
the reserved space size of the space balace, and then we can use
that space to create the relocation tree for each fs/file trees.
But it is hard to calculate the suitable size because we doesn't
know how many fs/file trees we need relocate.
We fixed this problem by reserving the space for relocation root creation
actively since the space it need is very small (one tree block, used for
root node copy), then we use that reserved space to create the
relocation tree. If we don't reserve space for relocation tree creation,
we will use the reserved space of the balance.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>