Pull more btrfs updates from Chris Mason:
"This has a few fixes since our last pull and a new ioctl for doing
btree searches from userland. It's very similar to the existing
ioctl, but lets us return larger items back down to the app"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
btrfs: fix error handling in create_pending_snapshot
btrfs: fix use of uninit "ret" in end_extent_writepage()
btrfs: free ulist in qgroup_shared_accounting() error path
Btrfs: fix qgroups sanity test crash or hang
btrfs: prevent RCU warning when dereferencing radix tree slot
Btrfs: fix unfinished readahead thread for raid5/6 degraded mounting
btrfs: new ioctl TREE_SEARCH_V2
btrfs: tree_search, search_ioctl: direct copy to userspace
btrfs: new function read_extent_buffer_to_user
btrfs: tree_search, copy_to_sk: return needed size on EOVERFLOW
btrfs: tree_search, copy_to_sk: return EOVERFLOW for too small buffer
btrfs: tree_search, search_ioctl: accept varying buffer
btrfs: tree_search: eliminate redundant nr_items check
If this condition in end_extent_writepage() is false:
if (tree->ops && tree->ops->writepage_end_io_hook)
we will then test an uninitialized "ret" at:
ret = ret < 0 ? ret : -EIO;
The test for ret is for the case where ->writepage_end_io_hook
failed, and we'd choose that ret as the error; but if
there is no ->writepage_end_io_hook, nothing sets ret.
Initializing ret to 0 should be sufficient; if
writepage_end_io_hook wasn't set, (!uptodate) means
non-zero err was passed in, so we choose -EIO in that case.
Signed-of-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
This new function reads the content of an extent directly to user memory.
Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
Pull btrfs updates from Chris Mason:
"The biggest change here is Josef's rework of the btrfs quota
accounting, which improves the in-memory tracking of delayed extent
operations.
I had been working on Btrfs stack usage for a while, mostly because it
had become impossible to do long stress runs with slab, lockdep and
pagealloc debugging turned on without blowing the stack. Even though
you upgraded us to a nice king sized stack, I kept most of the
patches.
We also have some very hard to find corruption fixes, an awesome sysfs
use after free, and the usual assortment of optimizations, cleanups
and other fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (80 commits)
Btrfs: convert smp_mb__{before,after}_clear_bit
Btrfs: fix scrub_print_warning to handle skinny metadata extents
Btrfs: make fsync work after cloning into a file
Btrfs: use right type to get real comparison
Btrfs: don't check nodes for extent items
Btrfs: don't release invalid page in btrfs_page_exists_in_range()
Btrfs: make sure we retry if page is a retriable exception
Btrfs: make sure we retry if we couldn't get the page
btrfs: replace EINVAL with EOPNOTSUPP for dev_replace raid56
trivial: fs/btrfs/ioctl.c: fix typo s/substract/subtract/
Btrfs: fix leaf corruption after __btrfs_drop_extents
Btrfs: ensure btrfs_prev_leaf doesn't miss 1 item
Btrfs: fix clone to deal with holes when NO_HOLES feature is enabled
btrfs: free delayed node outside of root->inode_lock
btrfs: replace EINVAL with ERANGE for resize when ULLONG_MAX
Btrfs: fix transaction leak during fsync call
btrfs: Avoid trucating page or punching hole in a already existed hole.
Btrfs: update commit root on snapshot creation after orphan cleanup
Btrfs: ioctl, don't re-lock extent range when not necessary
Btrfs: avoid visiting all extent items when cloning a range
...
__extent_writepage has two unrelated parts. First it does the delayed
allocation dance and second it does the mapping and IO for the page
we're actually writing.
This splits it up into those two parts so the stack from one doesn't
impact the stack from the other.
Signed-off-by: Chris Mason <clm@fb.com>
This adds noinline_for_stack to two helpers used by
btree_write_cache_pages. It shaves us down from 424 bytes on the
stack to 280.
Signed-off-by: Chris Mason <clm@fb.com>
We need to NULL the cached_state after freeing it, otherwise
we might free it again if find_delalloc_range doesn't find anything.
Signed-off-by: Chris Mason <clm@fb.com>
cc: stable@vger.kernel.org
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>
According to commit 865ffef379
(fs: fix fsync() error reporting),
it's not stable to just check error pages because pages can be
truncated or invalidated, we should also mark mapping with error
flag so that a later fsync can catch the error.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
When running low on available disk space and having several processes
doing buffered file IO, I got the following trace in dmesg:
[ 4202.720152] INFO: task kworker/u8:1:5450 blocked for more than 120 seconds.
[ 4202.720401] Not tainted 3.13.0-fdm-btrfs-next-26+ #1
[ 4202.720596] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 4202.720874] kworker/u8:1 D 0000000000000001 0 5450 2 0x00000000
[ 4202.720904] Workqueue: btrfs-flush_delalloc normal_work_helper [btrfs]
[ 4202.720908] ffff8801f62ddc38 0000000000000082 ffff880203ac2490 00000000001d3f40
[ 4202.720913] ffff8801f62ddfd8 00000000001d3f40 ffff8800c4f0c920 ffff880203ac2490
[ 4202.720918] 00000000001d4a40 ffff88020fe85a40 ffff88020fe85ab8 0000000000000001
[ 4202.720922] Call Trace:
[ 4202.720931] [<ffffffff816a3cb9>] schedule+0x29/0x70
[ 4202.720950] [<ffffffffa01ec48d>] btrfs_start_ordered_extent+0x6d/0x110 [btrfs]
[ 4202.720956] [<ffffffff8108e620>] ? bit_waitqueue+0xc0/0xc0
[ 4202.720972] [<ffffffffa01ec559>] btrfs_run_ordered_extent_work+0x29/0x40 [btrfs]
[ 4202.720988] [<ffffffffa0201987>] normal_work_helper+0x137/0x2c0 [btrfs]
[ 4202.720994] [<ffffffff810680e5>] process_one_work+0x1f5/0x530
(...)
[ 4202.721027] 2 locks held by kworker/u8:1/5450:
[ 4202.721028] #0: (%s-%s){++++..}, at: [<ffffffff81068083>] process_one_work+0x193/0x530
[ 4202.721037] #1: ((&work->normal_work)){+.+...}, at: [<ffffffff81068083>] process_one_work+0x193/0x530
[ 4202.721054] INFO: task btrfs:7891 blocked for more than 120 seconds.
[ 4202.721258] Not tainted 3.13.0-fdm-btrfs-next-26+ #1
[ 4202.721444] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 4202.721699] btrfs D 0000000000000001 0 7891 7890 0x00000001
[ 4202.721704] ffff88018c2119e8 0000000000000086 ffff8800a33d2490 00000000001d3f40
[ 4202.721710] ffff88018c211fd8 00000000001d3f40 ffff8802144b0000 ffff8800a33d2490
[ 4202.721714] ffff8800d8576640 ffff88020fe85bc0 ffff88020fe85bc8 7fffffffffffffff
[ 4202.721718] Call Trace:
[ 4202.721723] [<ffffffff816a3cb9>] schedule+0x29/0x70
[ 4202.721727] [<ffffffff816a2ebc>] schedule_timeout+0x1dc/0x270
[ 4202.721732] [<ffffffff8109bd79>] ? mark_held_locks+0xb9/0x140
[ 4202.721736] [<ffffffff816a90c0>] ? _raw_spin_unlock_irq+0x30/0x40
[ 4202.721740] [<ffffffff8109bf0d>] ? trace_hardirqs_on_caller+0x10d/0x1d0
[ 4202.721744] [<ffffffff816a488f>] wait_for_completion+0xdf/0x120
[ 4202.721749] [<ffffffff8107fa90>] ? try_to_wake_up+0x310/0x310
[ 4202.721765] [<ffffffffa01ebee4>] btrfs_wait_ordered_extents+0x1f4/0x280 [btrfs]
[ 4202.721781] [<ffffffffa020526e>] btrfs_mksubvol.isra.62+0x30e/0x5a0 [btrfs]
[ 4202.721786] [<ffffffff8108e620>] ? bit_waitqueue+0xc0/0xc0
[ 4202.721799] [<ffffffffa02056a9>] btrfs_ioctl_snap_create_transid+0x1a9/0x1b0 [btrfs]
[ 4202.721813] [<ffffffffa020583a>] btrfs_ioctl_snap_create_v2+0x10a/0x170 [btrfs]
(...)
It turns out that extent_io.c:__extent_writepage(), which ends up being called
through filemap_fdatawrite_range() in btrfs_start_ordered_extent(), was getting
-ENOSPC when calling the fill_delalloc callback. In this situation, it returned
without the writepage_end_io_hook callback (inode.c:btrfs_writepage_end_io_hook)
ever being called for the respective page, which prevents the ordered extent's
bytes_left count from ever reaching 0, and therefore a finish_ordered_fn work
is never queued into the endio_write_workers queue. This makes the task that
called btrfs_start_ordered_extent() hang forever on the wait queue of the ordered
extent.
This is fairly easy to reproduce using a small filesystem and fsstress on
a quad core vm:
mkfs.btrfs -f -b `expr 2100 \* 1024 \* 1024` /dev/sdd
mount /dev/sdd /mnt
fsstress -p 6 -d /mnt -n 100000 -x \
"btrfs subvolume snapshot -r /mnt /mnt/mysnap" \
-f allocsp=0 \
-f bulkstat=0 \
-f bulkstat1=0 \
-f chown=0 \
-f creat=1 \
-f dread=0 \
-f dwrite=0 \
-f fallocate=1 \
-f fdatasync=0 \
-f fiemap=0 \
-f freesp=0 \
-f fsync=0 \
-f getattr=0 \
-f getdents=0 \
-f link=0 \
-f mkdir=0 \
-f mknod=0 \
-f punch=1 \
-f read=0 \
-f readlink=0 \
-f rename=0 \
-f resvsp=0 \
-f rmdir=0 \
-f setxattr=0 \
-f stat=0 \
-f symlink=0 \
-f sync=0 \
-f truncate=1 \
-f unlink=0 \
-f unresvsp=0 \
-f write=4
So just ensure that if an error happens while writing the extent page
we call the writepage_end_io_hook callback. Also make it return the
error code and ensure the caller (extent_write_cache_pages) processes
all pages in the page vector even if an error happens only for some
of them, so that ordered extents end up released.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
aops->write_begin may allocate a new page and make it visible only to have
mark_page_accessed called almost immediately after. Once the page is
visible the atomic operations are necessary which is noticable overhead
when writing to an in-memory filesystem like tmpfs but should also be
noticable with fast storage. The objective of the patch is to initialse
the accessed information with non-atomic operations before the page is
visible.
The bulk of filesystems directly or indirectly use
grab_cache_page_write_begin or find_or_create_page for the initial
allocation of a page cache page. This patch adds an init_page_accessed()
helper which behaves like the first call to mark_page_accessed() but may
called before the page is visible and can be done non-atomically.
The primary APIs of concern in this care are the following and are used
by most filesystems.
find_get_page
find_lock_page
find_or_create_page
grab_cache_page_nowait
grab_cache_page_write_begin
All of them are very similar in detail to the patch creates a core helper
pagecache_get_page() which takes a flags parameter that affects its
behavior such as whether the page should be marked accessed or not. Then
old API is preserved but is basically a thin wrapper around this core
function.
Each of the filesystems are then updated to avoid calling
mark_page_accessed when it is known that the VM interfaces have already
done the job. There is a slight snag in that the timing of the
mark_page_accessed() has now changed so in rare cases it's possible a page
gets to the end of the LRU as PageReferenced where as previously it might
have been repromoted. This is expected to be rare but it's worth the
filesystem people thinking about it in case they see a problem with the
timing change. It is also the case that some filesystems may be marking
pages accessed that previously did not but it makes sense that filesystems
have consistent behaviour in this regard.
The test case used to evaulate this is a simple dd of a large file done
multiple times with the file deleted on each iterations. The size of the
file is 1/10th physical memory to avoid dirty page balancing. In the
async case it will be possible that the workload completes without even
hitting the disk and will have variable results but highlight the impact
of mark_page_accessed for async IO. The sync results are expected to be
more stable. The exception is tmpfs where the normal case is for the "IO"
to not hit the disk.
The test machine was single socket and UMA to avoid any scheduling or NUMA
artifacts. Throughput and wall times are presented for sync IO, only wall
times are shown for async as the granularity reported by dd and the
variability is unsuitable for comparison. As async results were variable
do to writback timings, I'm only reporting the maximum figures. The sync
results were stable enough to make the mean and stddev uninteresting.
The performance results are reported based on a run with no profiling.
Profile data is based on a separate run with oprofile running.
async dd
3.15.0-rc3 3.15.0-rc3
vanilla accessed-v2
ext3 Max elapsed 13.9900 ( 0.00%) 11.5900 ( 17.16%)
tmpfs Max elapsed 0.5100 ( 0.00%) 0.4900 ( 3.92%)
btrfs Max elapsed 12.8100 ( 0.00%) 12.7800 ( 0.23%)
ext4 Max elapsed 18.6000 ( 0.00%) 13.3400 ( 28.28%)
xfs Max elapsed 12.5600 ( 0.00%) 2.0900 ( 83.36%)
The XFS figure is a bit strange as it managed to avoid a worst case by
sheer luck but the average figures looked reasonable.
samples percentage
ext3 86107 0.9783 vmlinux-3.15.0-rc4-vanilla mark_page_accessed
ext3 23833 0.2710 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
ext3 5036 0.0573 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
ext4 64566 0.8961 vmlinux-3.15.0-rc4-vanilla mark_page_accessed
ext4 5322 0.0713 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
ext4 2869 0.0384 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
xfs 62126 1.7675 vmlinux-3.15.0-rc4-vanilla mark_page_accessed
xfs 1904 0.0554 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
xfs 103 0.0030 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
btrfs 10655 0.1338 vmlinux-3.15.0-rc4-vanilla mark_page_accessed
btrfs 2020 0.0273 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
btrfs 587 0.0079 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
tmpfs 59562 3.2628 vmlinux-3.15.0-rc4-vanilla mark_page_accessed
tmpfs 1210 0.0696 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
tmpfs 94 0.0054 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
[akpm@linux-foundation.org: don't run init_page_accessed() against an uninitialised pointer]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Tested-by: Prabhakar Lad <prabhakar.csengg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull second set of btrfs updates from Chris Mason:
"The most important changes here are from Josef, fixing a btrfs
regression in 3.14 that can cause corruptions in the extent allocation
tree when snapshots are in use.
Josef also fixed some deadlocks in send/recv and other assorted races
when balance is running"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (23 commits)
Btrfs: fix compile warnings on on avr32 platform
btrfs: allow mounting btrfs subvolumes with different ro/rw options
btrfs: export global block reserve size as space_info
btrfs: fix crash in remount(thread_pool=) case
Btrfs: abort the transaction when we don't find our extent ref
Btrfs: fix EINVAL checks in btrfs_clone
Btrfs: fix unlock in __start_delalloc_inodes()
Btrfs: scrub raid56 stripes in the right way
Btrfs: don't compress for a small write
Btrfs: more efficient io tree navigation on wait_extent_bit
Btrfs: send, build path string only once in send_hole
btrfs: filter invalid arg for btrfs resize
Btrfs: send, fix data corruption due to incorrect hole detection
Btrfs: kmalloc() doesn't return an ERR_PTR
Btrfs: fix snapshot vs nocow writting
btrfs: Change the expanding write sequence to fix snapshot related bug.
btrfs: make device scan less noisy
btrfs: fix lockdep warning with reclaim lock inversion
Btrfs: hold the commit_root_sem when getting the commit root during send
Btrfs: remove transaction from send
...
If we don't reschedule use rb_next to find the next extent state
instead of a full tree search, which is more efficient and safe
since we didn't release the io tree's lock.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
So I have an awful exercise script that will run snapshot, balance and
send/receive in parallel. This sometimes would crash spectacularly and when it
came back up the fs would be completely hosed. Turns out this is because of a
bad interaction of balance and send/receive. Send will hold onto its entire
path for the whole send, but its blocks could get relocated out from underneath
it, and because it doesn't old tree locks theres nothing to keep this from
happening. So it will go to read in a slot with an old transid, and we could
have re-allocated this block for something else and it could have a completely
different transid. But because we think it is invalid we clear uptodate and
re-read in the block. If we do this before we actually write out the new block
we could write back stale data to the fs, and boom we're screwed.
Now we definitely need to fix this disconnect between send and balance, but we
really really need to not allow ourselves to accidently read in stale data over
new data. So make sure we check if the extent buffer is not under io before
clearing uptodate, this will kick back EIO to the caller instead of reading in
stale data and keep us from corrupting the fs. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Pull btrfs changes from Chris Mason:
"This is a pretty long stream of bug fixes and performance fixes.
Qu Wenruo has replaced the btrfs async threads with regular kernel
workqueues. We'll keep an eye out for performance differences, but
it's nice to be using more generic code for this.
We still have some corruption fixes and other patches coming in for
the merge window, but this batch is tested and ready to go"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (108 commits)
Btrfs: fix a crash of clone with inline extents's split
btrfs: fix uninit variable warning
Btrfs: take into account total references when doing backref lookup
Btrfs: part 2, fix incremental send's decision to delay a dir move/rename
Btrfs: fix incremental send's decision to delay a dir move/rename
Btrfs: remove unnecessary inode generation lookup in send
Btrfs: fix race when updating existing ref head
btrfs: Add trace for btrfs_workqueue alloc/destroy
Btrfs: less fs tree lock contention when using autodefrag
Btrfs: return EPERM when deleting a default subvolume
Btrfs: add missing kfree in btrfs_destroy_workqueue
Btrfs: cache extent states in defrag code path
Btrfs: fix deadlock with nested trans handles
Btrfs: fix possible empty list access when flushing the delalloc inodes
Btrfs: split the global ordered extents mutex
Btrfs: don't flush all delalloc inodes when we doesn't get s_umount lock
Btrfs: reclaim delalloc metadata more aggressively
Btrfs: remove unnecessary lock in may_commit_transaction()
Btrfs: remove the unnecessary flush when preparing the pages
Btrfs: just do dirty page flush for the inode with compression before direct IO
...
When we split an extent state there's no need to start the rbtree search
from the root node - we can start it from the original extent state node,
since we would end up in its subtree if we do the search starting at the
root node anyway.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
We don't need to have an unsigned int field in the extent_map struct
to tell us whether the extent map is in the inode's extent_map tree or
not. We can use the rb_node struct field and the RB_CLEAR_NODE and
RB_EMPTY_NODE macros to achieve the same task.
This reduces sizeof(struct extent_map) from 152 bytes to 144 bytes (on a
64 bits system).
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Pull btrfs updates from Chris Mason:
"This is a pretty big pull, and most of these changes have been
floating in btrfs-next for a long time. Filipe's properties work is a
cool building block for inheriting attributes like compression down on
a per inode basis.
Jeff Mahoney kicked in code to export filesystem info into sysfs.
Otherwise, lots of performance improvements, cleanups and bug fixes.
Looks like there are still a few other small pending incrementals, but
I wanted to get the bulk of this in first"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (149 commits)
Btrfs: fix spin_unlock in check_ref_cleanup
Btrfs: setup inode location during btrfs_init_inode_locked
Btrfs: don't use ram_bytes for uncompressed inline items
Btrfs: fix btrfs_search_slot_for_read backwards iteration
Btrfs: do not export ulist functions
Btrfs: rework ulist with list+rb_tree
Btrfs: fix memory leaks on walking backrefs failure
Btrfs: fix send file hole detection leading to data corruption
Btrfs: add a reschedule point in btrfs_find_all_roots()
Btrfs: make send's file extent item search more efficient
Btrfs: fix to catch all errors when resolving indirect ref
Btrfs: fix protection between walking backrefs and root deletion
btrfs: fix warning while merging two adjacent extents
Btrfs: fix infinite path build loops in incremental send
btrfs: undo sysfs when open_ctree() fails
Btrfs: fix snprintf usage by send's gen_unique_name
btrfs: fix defrag 32-bit integer overflow
btrfs: sysfs: list the NO_HOLES feature
btrfs: sysfs: don't show reserved incompat feature
btrfs: call permission checks earlier in ioctls and return EPERM
...
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>
I need to create a fake tree to test qgroups and I don't want to have to setup a
fake btree_inode. The fact is we only use the radix tree for the fs_info, so
everybody else who allocates an extent_io_tree is just wasting the space anyway.
This patch moves the radix tree and its lock into btrfs_fs_info so there is less
stuff I have to fake to do qgroup sanity tests. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
For creating a dummy in-memory btree I need to be able to use the radix tree to
keep track of the buffers like normal extent buffers. With dummy buffers we
skip the radix tree step, and we still want to do that for the tree mod log
dummy buffers but for my test buffers we need to be able to remove them from the
radix tree like normal. This will give me a way to do that. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
I need to add infrastructure to allocate dummy extent buffers for running sanity
tests, and to do this I need to not have to worry about having an
address_mapping for an io_tree, so just fix up the places where we assume that
all io_tree's have a non-NULL ->mapping. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Currently we do 2 traversals of an inode's extent_io_tree
before inserting an extent state structure: 1 to see if a
matching extent state already exists and 1 to do the insertion
if the fist traversal didn't found such extent state.
This change just combines those tree traversals into a single one.
While running sysbench tests (random writes) I captured the number
of elements in extent_io_tree trees for a while (into a procfs file
backed by a seq_list from seq_file module) and got this histogram:
Count: 9310
Range: 51.000 - 21386.000; Mean: 11785.243; Median: 18743.500; Stddev: 8923.688
Percentiles: 90th: 20985.000; 95th: 21155.000; 99th: 21369.000
51.000 - 93.933: 693 ########
93.933 - 172.314: 938 ##########
172.314 - 315.408: 856 #########
315.408 - 576.646: 95 #
576.646 - 6415.830: 888 ##########
6415.830 - 11713.809: 1024 ###########
11713.809 - 21386.000: 4816 #####################################################
So traversing such trees can take some significant time that can
easily be avoided.
Ran the following sysbench tests, 5 times each, for sequential and
random writes, and got the following results:
sysbench --test=fileio --file-num=1 --file-total-size=2G \
--file-test-mode=seqwr --num-threads=16 --file-block-size=65536 \
--max-requests=0 --max-time=60 --file-io-mode=sync
sysbench --test=fileio --file-num=1 --file-total-size=2G \
--file-test-mode=rndwr --num-threads=16 --file-block-size=65536 \
--max-requests=0 --max-time=60 --file-io-mode=sync
Before this change:
sequential writes: 69.28Mb/sec (average of 5 runs)
random writes: 4.14Mb/sec (average of 5 runs)
After this change:
sequential writes: 69.91Mb/sec (average of 5 runs)
random writes: 5.69Mb/sec (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>
When we didn't find a matching extent state, we inserted a new one
but didn't cache it in the **cached_state parameter, which makes a
subsequent call do a tree lookup to get it.
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>
Linus Torvalds
Eric Sandeen
Gerhard Heift
Chris Mason
Josef Bacik
Liu Bo
Filipe Manana
Mel Gorman
Peter Zijlstra
Frank Holton