fs_devices->devices is only updated on remove and add device paths, so we can
use rcu to protect it in the reader side
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Drop device_list_mutex for the reader side on clone_fs_devices and
btrfs_rm_device pathes since the fs_info->volume_mutex can ensure the device
list is not updated
btrfs_close_extra_devices is the initialized path, we can not add or remove
device at this time, so we can simply drop the mutex safely, like other
initialized function does(add_missing_dev, __find_device, __btrfs_open_devices
...).
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
On remove device path, it updates device->dev_alloc_list but does not hold
chunk lock
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
On btrfs_congested_fn and __unplug_io_fn paths, we should hold
device_list_mutex to avoid remove/add device path to
update fs_devices->devices
On __btrfs_close_devices and btrfs_prepare_sprout paths, the devices in
fs_devices->devices or fs_devices->devices is updated, so we should hold
the mutex to avoid the reader side to reach them
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
'bh' is forgot to release if no error is detected
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
merge_state can free the current state if it can be merged with the next node,
but in set_extent_bit(), after merge_state, we still use the current extent to
get the next node and cache it into cached_state
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
It doesn't allocate extent_state and check the result properly:
- in set_extent_bit, it doesn't allocate extent_state if the path is not
allowed wait
- in clear_extent_bit, it doesn't check the result after atomic-ly allocate,
we trigger BUG_ON() if it's fail
- if allocate fail, we trigger BUG_ON instead of returning -ENOMEM since
the return value of clear_extent_bit() is ignored by many callers
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Btrfs_alloc_path should be matched with btrfs_free_path in error-handling code.
A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@r exists@
local idexpression struct btrfs_path * x;
expression ra,rb;
position p1,p2;
@@
x = btrfs_alloc_path@p1(...)
... when != btrfs_free_path(x,...)
when != if (...) { ... btrfs_free_path(x,...) ...}
when != x = ra
if(...) { ... when != x = rb
when forall
when != btrfs_free_path(x,...)
\(return <+...x...+>; \| return@p2...; \) }
@script:python@
p1 << r.p1;
p2 << r.p2;
@@
cocci.print_main("alloc",p1)
cocci.print_secs("return",p2)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
If return value of btrfs_inc_extent_ref() is not 0, BUG() is called.
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
When read_one_inode() fails, error code is returned to caller instead
of BUG_ON().
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Currently, btrfs_truncate_item and btrfs_extend_item returns only 0.
So, the check by BUG_ON in the caller is unnecessary.
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
The error code is returned instead of calling BUG_ON when
btrfs_del_item returns the error.
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
The error code is returned instead of calling BUG_ON when
btrfs_previous_item returns the error.
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Observed as a large delay when --mixed filesystem is filled up.
Test example:
1. create tiny --mixed FS:
$ dd if=/dev/zero of=2G.img seek=$((2048 * 1024 * 1024 - 1)) count=1 bs=1
$ mkfs.btrfs --mixed 2G.img
$ mount -oloop 2G.img /mnt/ut/
2. Try to fill it up:
$ dd if=/dev/urandom of=10M.file bs=10240 count=1024
$ seq 1 256 | while read file_no; do echo $file_no; time cp 10M.file ${file_no}.copy; done
Up to '200.copy' it goes fast, but when disk fills-up each -ENOSPC
message takes 3 seconds to pop-up _every_ ENOSPC (and in usermode linux
it's even more: 30-60 seconds!). (Maybe, time depends on kernel's timer resolution).
No IO, no CPU load, just rescheduling. Some debugging revealed busy spinning
in shrink_delalloc.
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
In 2008, commit b4f6c45dfb dropped the use
of fs/btrfs/version.sh, but left the script behind. Kill it.
Commit by Jamey Sharp and Josh Triplett.
Signed-off-by: Jamey Sharp <jamey@minilop.net>
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Btrfs's tree search ioctl has a field to indicate that no more than a
given number of records should be returned. The ioctl doesn't honour
this, as the tested value is not incremented until the end of the
copy_to_sk function. This patch removes an unnecessary local variable,
and updates the num_found counter as each key is found in the tree.
Signed-off-by: Hugo Mills <hugo@carfax.org.uk>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
240f62c875 replaced the node_lock with rcu_read_lock, but forgot
to remove the actual lock in the data structure. Remove it here.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
The current code relogs the entire inode every time during fsync log,
and it is much better suited to small files rather than large ones.
During my performance test, the fsync performace of large files sucks,
and we can ascribe this to the tremendous amount of csum infos of the
large ones, cause we have to flush all of these csum infos into log trees
even when there are only _one_ change in the whole file data. Apparently,
to optimize fsync, we need to create a filter to skip the unnecessary csum
ones, that is, the corresponding file data remains unchanged before this fsync.
Here I have some test results to show, I use sysbench to do "random write + fsync".
===
sysbench --test=fileio --num-threads=1 --file-num=2 --file-block-size=4K --file-total-size=8G --file-test-mode=rndwr --file-io-mode=sync --file-extra-flags= [prepare, run]
===
Sysbench args:
- Number of threads: 1
- Extra file open flags: 0
- 2 files, 4Gb each
- Block size 4Kb
- Number of random requests for random IO: 10000
- Read/Write ratio for combined random IO test: 1.50
- Periodic FSYNC enabled, calling fsync() each 100 requests.
- Calling fsync() at the end of test, Enabled.
- Using synchronous I/O mode
- Doing random write test
Sysbench results:
===
Operations performed: 0 Read, 10000 Write, 200 Other = 10200 Total
Read 0b Written 39.062Mb Total transferred 39.062Mb
===
a) without patch: (*SPEED* : 451.01Kb/sec)
112.75 Requests/sec executed
b) with patch: (*SPEED* : 4.7533Mb/sec)
1216.84 Requests/sec executed
PS: I've made a _sub transid_ stuff patch, but it does not perform as effectively as this patch,
and I'm wanderring where the problem is and trying to improve it more.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Changelog V5 -> V6:
- Fix oom when the memory load is high, by storing the delayed nodes into the
root's radix tree, and letting btrfs inodes go.
Changelog V4 -> V5:
- Fix the race on adding the delayed node to the inode, which is spotted by
Chris Mason.
- Merge Chris Mason's incremental patch into this patch.
- Fix deadlock between readdir() and memory fault, which is reported by
Itaru Kitayama.
Changelog V3 -> V4:
- Fix nested lock, which is reported by Itaru Kitayama, by updating space cache
inode in time.
Changelog V2 -> V3:
- Fix the race between the delayed worker and the task which does delayed items
balance, which is reported by Tsutomu Itoh.
- Modify the patch address David Sterba's comment.
- Fix the bug of the cpu recursion spinlock, reported by Chris Mason
Changelog V1 -> V2:
- break up the global rb-tree, use a list to manage the delayed nodes,
which is created for every directory and file, and used to manage the
delayed directory name index items and the delayed inode item.
- introduce a worker to deal with the delayed nodes.
Compare with Ext3/4, the performance of file creation and deletion on btrfs
is very poor. the reason is that btrfs must do a lot of b+ tree insertions,
such as inode item, directory name item, directory name index and so on.
If we can do some delayed b+ tree insertion or deletion, we can improve the
performance, so we made this patch which implemented delayed directory name
index insertion/deletion and delayed inode update.
Implementation:
- introduce a delayed root object into the filesystem, that use two lists to
manage the delayed nodes which are created for every file/directory.
One is used to manage all the delayed nodes that have delayed items. And the
other is used to manage the delayed nodes which is waiting to be dealt with
by the work thread.
- Every delayed node has two rb-tree, one is used to manage the directory name
index which is going to be inserted into b+ tree, and the other is used to
manage the directory name index which is going to be deleted from b+ tree.
- introduce a worker to deal with the delayed operation. This worker is used
to deal with the works of the delayed directory name index items insertion
and deletion and the delayed inode update.
When the delayed items is beyond the lower limit, we create works for some
delayed nodes and insert them into the work queue of the worker, and then
go back.
When the delayed items is beyond the upper bound, we create works for all
the delayed nodes that haven't been dealt with, and insert them into the work
queue of the worker, and then wait for that the untreated items is below some
threshold value.
- When we want to insert a directory name index into b+ tree, we just add the
information into the delayed inserting rb-tree.
And then we check the number of the delayed items and do delayed items
balance. (The balance policy is above.)
- When we want to delete a directory name index from the b+ tree, we search it
in the inserting rb-tree at first. If we look it up, just drop it. If not,
add the key of it into the delayed deleting rb-tree.
Similar to the delayed inserting rb-tree, we also check the number of the
delayed items and do delayed items balance.
(The same to inserting manipulation)
- When we want to update the metadata of some inode, we cached the data of the
inode into the delayed node. the worker will flush it into the b+ tree after
dealing with the delayed insertion and deletion.
- We will move the delayed node to the tail of the list after we access the
delayed node, By this way, we can cache more delayed items and merge more
inode updates.
- If we want to commit transaction, we will deal with all the delayed node.
- the delayed node will be freed when we free the btrfs inode.
- Before we log the inode items, we commit all the directory name index items
and the delayed inode update.
I did a quick test by the benchmark tool[1] and found we can improve the
performance of file creation by ~15%, and file deletion by ~20%.
Before applying this patch:
Create files:
Total files: 50000
Total time: 1.096108
Average time: 0.000022
Delete files:
Total files: 50000
Total time: 1.510403
Average time: 0.000030
After applying this patch:
Create files:
Total files: 50000
Total time: 0.932899
Average time: 0.000019
Delete files:
Total files: 50000
Total time: 1.215732
Average time: 0.000024
[1] http://marc.info/?l=linux-btrfs&m=128212635122920&q=p3
Many thanks for Kitayama-san's help!
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: David Sterba <dave@jikos.cz>
Tested-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Tested-by: Itaru Kitayama <kitayama@cl.bb4u.ne.jp>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2:
configfs: Fix race between configfs_readdir() and configfs_d_iput()
configfs: Don't try to d_delete() negative dentries.
ocfs2/dlm: Target node death during resource migration leads to thread spin
ocfs2: Skip mount recovery for hard-ro mounts
ocfs2/cluster: Heartbeat mismatch message improved
ocfs2/cluster: Increase the live threshold for global heartbeat
ocfs2/dlm: Use negotiated o2dlm protocol version
ocfs2: skip existing hole when removing the last extent_rec in punching-hole codes.
ocfs2: Initialize data_ac (might be used uninitialized)
* 'devicetree/merge' of git://git.secretlab.ca/git/linux-2.6:
drivercore: revert addition of of_match to struct device
of: fix race when matching drivers
Commit b826291c, "drivercore/dt: add a match table pointer to struct
device" added an of_match pointer to struct device to cache the
of_match_table entry discovered at driver match time. This was unsafe
because matching is not an atomic operation with probing a driver. If
two or more drivers are attempted to be matched to a driver at the
same time, then the cached matching entry pointer could get
overwritten.
This patch reverts the of_match cache pointer and reworks all users to
call of_match_device() directly instead.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
If two drivers are probing devices at the same time, both will write
their match table result to the dev->of_match cache at the same time.
Only write the result if the device matches.
In a thread titled "SBus devices sometimes detected, sometimes not",
Meelis reported his SBus hme was not detected about 50% of the time.
From the debug suggested by Grant it was obvious another driver matched
some devices between the call to match the hme and the hme discovery
failling.
Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Milton Miller <miltonm@bga.com>
[grant.likely: modified to only call of_match_device() once]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
block: don't delay blk_run_queue_async
scsi: remove performance regression due to async queue run
blk-throttle: Use task_subsys_state() to determine a task's blkio_cgroup
block: rescan partitions on invalidated devices on -ENOMEDIA too
cdrom: always check_disk_change() on open
block: unexport DISK_EVENT_MEDIA_CHANGE for legacy/fringe drivers
The 'size' variable contains the correct register size for both AR7
and Titan, but we never used it to ioremap the correct register size.
This problem only shows up on Titan.
[ralf@linux-mips.org: Fixed the fix. The original patch as in patchwork
recognizes the problem correctly then fails to fix it ...]
Reported-by: Alexander Clouter <alex@digriz.org.uk>
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Patchwork: https://patchwork.linux-mips.org/patch/2380/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This is the MIPS portion of Joe Perches <joe@perches.com>'s
https://patchwork.linux-mips.org/patch/2172/ which seems to have been
lost in time and space.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
configfs_readdir() will use the existing inode numbers of inodes in the
dcache, but it makes them up for attribute files that aren't currently
instantiated. There is a race where a closing attribute file can be
tearing down at the same time as configfs_readdir() is trying to get its
inode number.
We want to get the inode number of open attribute files, because they
should match while instantiated. We can't lock down the transition
where dentry->d_inode is set to NULL, so we just check for NULL there.
We can, however, ensure that an inode we find isn't iput() in
configfs_d_iput() until after we've accessed it.
Signed-off-by: Joel Becker <jlbec@evilplan.org>
When configfs is faking mkdir() on its subsystem or default group
objects, it starts by adding a negative dentry. It then tries to
instantiate the group. If that should fail, it must clean up after
itself.
I was using d_delete() here, but configfs_attach_group() promises to
return an empty dentry on error. d_delete() explodes with the entry
dentry. Let's try d_drop() instead. The unhashing is what we want for
our dentry.
Signed-off-by: Joel Becker <jlbec@evilplan.org>
Let's check a scenario:
1. blk_delay_queue(q, SCSI_QUEUE_DELAY);
2. blk_run_queue_async();
the second one will became a noop, because q->delay_work already has
WORK_STRUCT_PENDING_BIT set, so the delayed work will still run after
SCSI_QUEUE_DELAY. But blk_run_queue_async actually hopes the delayed
work runs immediately.
Fix this by doing a cancel on potentially pending delayed work
before queuing an immediate run of the workqueue.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf evlist: Fix per thread mmap setup
perf tools: Honour the cpu list parameter when also monitoring a thread list
kprobes, x86: Disable irqs during optimized callback
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
cifs: fix cifsConvertToUCS() for the mapchars case
cifs: add fallback in is_path_accessible for old servers
Provide a stub for proc_mkdir_mode() when CONFIG_PROC_FS is not
enabled, just like the stub for proc_mkdir().
Fixes this linux-next build error:
drivers/net/wireless/airo.c:4504: error: implicit declaration of function 'proc_mkdir_mode'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
os_dump_core() uses abort() to terminate UML in case of an fatal error.
glibc's abort() calls raise(SIGABRT) which makes use of tgkill().
tgkill() has no effect within UML's kernel threads because they are not
pthreads. As fallback abort() executes an invalid instruction to
terminate the process. Therefore UML gets killed by SIGSEGV and leaves a
ugly log entry in the host's kernel ring buffer.
To get rid of this we use our own abort routine.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ZONE_CONGESTED should be a state of global memory reclaim. If not, a busy
memcg sets this and give unnecessary throttoling in wait_iff_congested()
against memory recalim in other contexts. This makes system performance
bad.
I'll think about "memcg is congested!" flag is required or not, later.
But this fix is required first.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: Ying Han <yinghan@google.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Adding the necessary MODULE_DEVICE_TABLE() information allows the driver
to be automatically loaded by udev.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
