linux-stable.git/fs/fuse, branch v3.12.44

fuse: notify: don't move pages

2015-04-09T11:14:02+00:00

commit 0d2783626a53d4c922f82d51fa675cb5d13f0d36 upstream.

fuse_try_move_page() is not prepared for replacing pages that have already
been read.

Reported-by: Al Viro 
Signed-off-by: Miklos Szeredi 
Signed-off-by: Jiri Slaby

fuse: set stolen page uptodate

2015-04-09T11:14:01+00:00

commit aa991b3b267e24f578bac7b09cc57579b660304b upstream.

Regular pipe buffers' ->steal method (generic_pipe_buf_steal()) doesn't set
PG_uptodate.

Don't warn on this condition, just set the uptodate flag.

Signed-off-by: Miklos Szeredi 
Signed-off-by: Jiri Slaby

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

2014-09-26T09:52:05+00:00

commit 2457aec63745e235bcafb7ef312b182d8682f0fc upstream.

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 
Signed-off-by: Mel Gorman 
Signed-off-by: Jiri Slaby

mm: page_alloc: convert hot/cold parameter and immediate callers to bool

2014-09-26T09:52:03+00:00

commit b745bc85f21ea707e4ea1a91948055fa3e72c77b upstream.

cold is a bool, make it one.  Make the likely case the "if" part of the
block instead of the else as according to the optimisation manual this is
preferred.

Signed-off-by: Mel Gorman 
Acked-by: Rik van Riel 
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: Peter Zijlstra 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Mel Gorman 
Signed-off-by: Jiri Slaby

callers of iov_copy_from_user_atomic() don't need pagecache_disable()

2014-09-26T09:51:58+00:00

commit 9e8c2af96e0d2d5fe298dd796fb6bc16e888a48d upstream.

... it does that itself (via kmap_atomic())

Signed-off-by: Al Viro 
Signed-off-by: Mel Gorman 
Signed-off-by: Jiri Slaby

fuse: ignore entry-timeout on LOOKUP_REVAL

2014-07-29T14:45:42+00:00

commit 154210ccb3a871e631bf39fdeb7a8731d98af87b upstream.

The following test case demonstrates the bug:

  sh# mount -t glusterfs localhost:meta-test /mnt/one

  sh# mount -t glusterfs localhost:meta-test /mnt/two

  sh# echo stuff > /mnt/one/file; rm -f /mnt/two/file; echo stuff > /mnt/one/file
  bash: /mnt/one/file: Stale file handle

  sh# echo stuff > /mnt/one/file; rm -f /mnt/two/file; sleep 1; echo stuff > /mnt/one/file

On the second open() on /mnt/one, FUSE would have used the old
nodeid (file handle) trying to re-open it. Gluster is returning
-ESTALE. The ESTALE propagates back to namei.c:filename_lookup()
where lookup is re-attempted with LOOKUP_REVAL. The right
behavior now, would be for FUSE to ignore the entry-timeout and
and do the up-call revalidation. Instead FUSE is ignoring
LOOKUP_REVAL, succeeding the revalidation (because entry-timeout
has not passed), and open() is again retried on the old file
handle and finally the ESTALE is going back to the application.

Fix: if revalidation is happening with LOOKUP_REVAL, then ignore
entry-timeout and always do the up-call.

Signed-off-by: Anand Avati 
Reviewed-by: Niels de Vos 
Signed-off-by: Miklos Szeredi 
Signed-off-by: Jiri Slaby

fuse: handle large user and group ID

2014-07-29T14:45:42+00:00

commit 233a01fa9c4c7c41238537e8db8434667ff28a2f upstream.

If the number in "user_id=N" or "group_id=N" mount options was larger than
INT_MAX then fuse returned EINVAL.

Fix this to handle all valid uid/gid values.

Signed-off-by: Miklos Szeredi 
Signed-off-by: Jiri Slaby

fuse: timeout comparison fix

2014-07-29T14:45:42+00:00

commit 126b9d4365b110c157bc4cbc32540dfa66c9c85a upstream.

As suggested by checkpatch.pl, use time_before64() instead of direct
comparison of jiffies64 values.

Signed-off-by: Miklos Szeredi 
Signed-off-by: Jiri Slaby

fuse: fix pipe_buf_operations

2014-02-13T21:50:10+00:00

commit 28a625cbc2a14f17b83e47ef907b2658576a32aa upstream.

Having this struct in module memory could Oops when if the module is
unloaded while the buffer still persists in a pipe.

Since sock_pipe_buf_ops is essentially the same as fuse_dev_pipe_buf_steal
merge them into nosteal_pipe_buf_ops (this is the same as
default_pipe_buf_ops except stealing the page from the buffer is not
allowed).

Reported-by: Al Viro 
Signed-off-by: Miklos Szeredi 
Signed-off-by: Greg Kroah-Hartman

fuse: no RCU mode in fuse_access()

2013-10-01T14:41:23+00:00

fuse_access() is never called in RCU walk, only on the final component of
access(2) and chdir(2)...

Signed-off-by: Miklos Szeredi