linux-stable.git/fs/f2fs/node.c, branch v3.16

f2fs: check bdi->dirty_exceeded when trying to skip data writes

2014-07-09T12:59:45+00:00

If we don't check the current backing device status, balance_dirty_pages can
fall into infinite pausing routine.

This can be occurred when a lot of directories make a small number of dirty
dentry pages including files.

Reported-by: Brian Chadwick 
Signed-off-by: Jaegeuk Kim

Merge tag 'for-f2fs-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

2014-06-10T02:11:44+00:00

Pull f2fs updates from Jaegeuk Kim:
 "In this round, there is no special interesting feature, but we've
  investigated a couple of tuning points with respect to the I/O flow.
  Several major bug fixes and a bunch of clean-ups also have been made.

  This patch-set includes the following major enhancement patches:
   - enhance wait_on_page_writeback
   - support SEEK_DATA and SEEK_HOLE
   - enhance readahead flows
   - enhance IO flushes
   - support fiemap
   - add some tracepoints

  The other bug fixes are as follows:
   - fix to support a large volume > 2TB correctly
   - recovery bug fix wrt fallocated space
   - fix recursive lock on xattr operations
   - fix some cases on the remount flow

  And, there are a bunch of cleanups"

* tag 'for-f2fs-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (52 commits)
  f2fs: support f2fs_fiemap
  f2fs: avoid not to call remove_dirty_inode
  f2fs: recover fallocated space
  f2fs: fix to recover data written by dio
  f2fs: large volume support
  f2fs: avoid crash when trace f2fs_submit_page_mbio event in ra_sum_pages
  f2fs: avoid overflow when large directory feathure is enabled
  f2fs: fix recursive lock by f2fs_setxattr
  MAINTAINERS: add a co-maintainer from samsung for F2FS
  MAINTAINERS: change the email address for f2fs
  f2fs: use inode_init_owner() to simplify codes
  f2fs: avoid to use slab memory in f2fs_issue_flush for efficiency
  f2fs: add a tracepoint for f2fs_read_data_page
  f2fs: add a tracepoint for f2fs_write_{meta,node,data}_pages
  f2fs: add a tracepoint for f2fs_write_{meta,node,data}_page
  f2fs: add a tracepoint for f2fs_write_end
  f2fs: add a tracepoint for f2fs_write_begin
  f2fs: fix checkpatch warning
  f2fs: deactivate inode page if the inode is evicted
  f2fs: decrease the lock granularity during write_begin
  ...

mm: non-atomically mark page accessed during page cache allocation where possible

2014-06-04T23:54:10+00:00

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 
Cc: Johannes Weiner 
Cc: Vlastimil Babka 
Cc: Jan Kara 
Cc: Michal Hocko 
Cc: Hugh Dickins 
Cc: Dave Hansen 
Cc: Theodore Ts'o 
Cc: "Paul E. McKenney" 
Cc: Oleg Nesterov 
Cc: Rik van Riel 
Cc: Peter Zijlstra 
Tested-by: Prabhakar Lad 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

f2fs: fix to recover data written by dio

2014-06-04T09:41:38+00:00

If data are overwritten through dio, previous f2fs doesn't remain the fsync mark
due to no additional node writes.

Note that this patch should resolve the xfstests:311.

Signed-off-by: Jaegeuk Kim

f2fs: avoid crash when trace f2fs_submit_page_mbio event in ra_sum_pages

2014-06-04T04:34:30+00:00

Previously we allocate pages with no mapping in ra_sum_pages(), so we may
encounter a crash in event trace of f2fs_submit_page_mbio where we access
mapping data of the page.

We'd better allocate pages in bd_inode mapping and invalidate these pages after
we restore data from pages. It could avoid crash in above scenario.

Changes from V1
 o remove redundant code in ra_sum_pages() suggested by Jaegeuk Kim.

Call Trace:
 [] ? ftrace_raw_event_f2fs_write_checkpoint+0x80/0x80 [f2fs]
 [] f2fs_submit_page_mbio+0x1cb/0x200 [f2fs]
 [] restore_node_summary+0x13a/0x280 [f2fs]
 [] build_curseg+0x2bd/0x620 [f2fs]
 [] build_segment_manager+0x1cb/0x920 [f2fs]
 [] f2fs_fill_super+0x535/0x8e0 [f2fs]
 [] mount_bdev+0x16a/0x1a0
 [] f2fs_mount+0x1f/0x30 [f2fs]
 [] mount_fs+0x36/0x170
 [] vfs_kern_mount+0x55/0xe0
 [] do_mount+0x1e8/0x900
 [] SyS_mount+0x82/0xc0
 [] sysenter_do_call+0x12/0x22

Suggested-by: Jaegeuk Kim 
Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: add a tracepoint for f2fs_write_{meta,node,data}_pages

2014-05-07T01:21:59+00:00

This patch adds a tracepoint for f2fs_write_{meta,node,data}_pages to trace when
pages are fsyncing/flushing.

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: add a tracepoint for f2fs_write_{meta,node,data}_page

2014-05-07T01:21:59+00:00

This patch adds a tracepoint for f2fs_write_{meta,node,data}_page to trace when
page is writting out.

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: split grab_cache_page and wait_on_page_writeback for node pages

2014-05-07T01:21:58+00:00

This patch splits grab_cache_page_write_begin into grab_cache_page and
wait_on_page_writeback for node pages.

This patch intends to enhance the latency to get node pages by alleviating
unnecessary wait_on_page_writeback.

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: adjust free mem size to flush dentry blocks

2014-05-07T01:21:55+00:00

If so many dirty dentry blocks are cached, not reached to the flush condition,
we should fall into livelock in balance_dirty_pages.
So, let's consider the mem size for the condition.

Signed-off-by: Jaegeuk Kim

f2fs: avoid BUG_ON when mouting corrupted image having garbage blocks

2014-05-07T01:21:55+00:00

If the disk has some garbage blocks, F2FS is able to face with BUG_ON when
recovering direct node blocks.
This patch detects the error case and avoids that prior to reaching BUG_ON.

Alexey Khoroshilov addressed the potential security issues as follows.
"An ability to trigger a BUG_ON assert by mounting a crafted image is
usually considered as a local denial of service [1-3]. As far as I
understand, the reason is that some kernel data may become inconsistent
that can lead to further problems.

[1] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-3353
[2] http://www.openwall.com/lists/oss-security/2011/06/24/4
[3] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-2928
etc."

Reported-by: Andrey Tsyvarev 
Cc: Alexey Khoroshilov 
Signed-off-by: Jaegeuk Kim