linux.git/fs, branch v4.7-rc2

devpts: Make each mount of devpts an independent filesystem.

2016-06-05T17:36:01+00:00

The /dev/ptmx device node is changed to lookup the directory entry "pts"
in the same directory as the /dev/ptmx device node was opened in.  If
there is a "pts" entry and that entry is a devpts filesystem /dev/ptmx
uses that filesystem.  Otherwise the open of /dev/ptmx fails.

The DEVPTS_MULTIPLE_INSTANCES configuration option is removed, so that
userspace can now safely depend on each mount of devpts creating a new
instance of the filesystem.

Each mount of devpts is now a separate and equal filesystem.

Reserved ttys are now available to all instances of devpts where the
mounter is in the initial mount namespace.

A new vfs helper path_pts is introduced that finds a directory entry
named "pts" in the directory of the passed in path, and changes the
passed in path to point to it.  The helper path_pts uses a function
path_parent_directory that was factored out of follow_dotdot.

In the implementation of devpts:
 - devpts_mnt is killed as it is no longer meaningful if all mounts of
   devpts are equal.
 - pts_sb_from_inode is replaced by just inode->i_sb as all cached
   inodes in the tty layer are now from the devpts filesystem.
 - devpts_add_ref is rolled into the new function devpts_ptmx.  And the
   unnecessary inode hold is removed.
 - devpts_del_ref is renamed devpts_release and reduced to just a
   deacrivate_super.
 - The newinstance mount option continues to be accepted but is now
   ignored.

In devpts_fs.h definitions for when !CONFIG_UNIX98_PTYS are removed as
they are never used.

Documentation/filesystems/devices.txt is updated to describe the current
situation.

This has been verified to work properly on openwrt-15.05, centos5,
centos6, centos7, debian-6.0.2, debian-7.9, debian-8.2, ubuntu-14.04.3,
ubuntu-15.10, fedora23, magia-5, mint-17.3, opensuse-42.1,
slackware-14.1, gentoo-20151225 (13.0?), archlinux-2015-12-01.  With the
caveat that on centos6 and on slackware-14.1 that there wind up being
two instances of the devpts filesystem mounted on /dev/pts, the lower
copy does not end up getting used.

Signed-off-by: "Eric W. Biederman" 
Cc: Greg KH 
Cc: Peter Hurley 
Cc: Peter Anvin 
Cc: Andy Lutomirski 
Cc: Al Viro 
Cc: Serge Hallyn 
Cc: Willy Tarreau 
Cc: Aurelien Jarno 
Cc: One Thousand Gnomes 
Cc: Jann Horn 
Cc: Jiri Slaby 
Cc: Florian Weimer 
Cc: Konstantin Khlebnikov 
Signed-off-by: Linus Torvalds

Merge branch 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

2016-06-04T18:56:28+00:00

Pull btrfs fixes from Chris Mason:
 "The important part of this pull is Filipe's set of fixes for btrfs
  device replacement.  Filipe fixed a few issues seen on the list and a
  number he found on his own"

* 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: deal with duplciates during extent_map insertion in btrfs_get_extent
  Btrfs: fix race between device replace and read repair
  Btrfs: fix race between device replace and discard
  Btrfs: fix race between device replace and chunk allocation
  Btrfs: fix race setting block group back to RW mode during device replace
  Btrfs: fix unprotected assignment of the left cursor for device replace
  Btrfs: fix race setting block group readonly during device replace
  Btrfs: fix race between device replace and block group removal
  Btrfs: fix race between readahead and device replace/removal

Btrfs: deal with duplciates during extent_map insertion in btrfs_get_extent

2016-06-03T19:32:34+00:00

When dealing with inline extents, btrfs_get_extent will incorrectly try
to insert a duplicate extent_map.  The dup hits -EEXIST from
add_extent_map, but then we try to merge with the existing one and end
up trying to insert a zero length extent_map.

This actually works most of the time, except when there are extent maps
past the end of the inline extent.  rocksdb will trigger this sometimes
because it preallocates an extent and then truncates down.

Josef made a script to trigger with xfs_io:

	#!/bin/bash

	xfs_io -f -c "pwrite 0 1000" inline
	xfs_io -c "falloc -k 4k 1M" inline
	xfs_io -c "pread 0 1000" -c "fadvise -d 0 1000" -c "pread 0 1000" inline
	xfs_io -c "fadvise -d 0 1000" inline
	cat inline

You'll get EIOs trying to read inline after this because add_extent_map
is returning EEXIST

Signed-off-by: Chris Mason

ceph: use i_version to check validity of fscache

2016-06-01T08:32:14+00:00

Signed-off-by: Yan, Zheng

ceph: improve fscache revalidation

2016-06-01T08:31:50+00:00

There are several issues in fscache revalidation code.
- In ceph_revalidate_work(), fscache_invalidate() is called when
  fscache_check_consistency() return 0. This is complete wrong
  because 0 means cache is valid.
- Handle_cap_grant() calls ceph_queue_revalidate() if client
  already has CAP_FILE_CACHE. This code is confusing. Client
  should revalidate the cache each time it got CAP_FILE_CACHE
  anew.
- In Handle_cap_grant(), fscache_invalidate() is called if MDS
  revokes CAP_FILE_CACHE. This is inconsistency with the case
  that inode get evicted. In the later case, the cache is not
  discarded. Client may use the cache when inode is reloaded.

This patch moves the fscache revalidation into ceph_get_caps().
Client revalidates the cache after it gets CAP_FILE_CACHE.
i_rdcache_gen should keep constance while CAP_FILE_CACHE is
used. If i_fscache_gen is not equal to i_rdcache_gen, client
needs to check cache's consistency.

Signed-off-by: Yan, Zheng

ceph: disable fscache when inode is opened for write

2016-06-01T08:31:07+00:00

All other filesystems do not add dirty pages to fscache. They all
disable fscache when inode is opened for write. Only ceph adds
dirty pages to fscache, but the code is buggy.

Signed-off-by: Yan, Zheng

ceph: avoid unnecessary fscache invalidation/revlidation

2016-06-01T08:30:41+00:00

ceph_fill_file_size() has already called ceph_fscache_invalidate()
if it return true.

Signed-off-by: Yan, Zheng

ceph: call __fscache_uncache_page() if readpages fails

2016-06-01T08:30:12+00:00

If readpages fails, fscache needs to cleanup its internal state.

Signed-off-by: Yan, Zheng

FS-Cache: make check_consistency callback return int

2016-06-01T08:29:39+00:00

__fscache_check_consistency() calls check_consistency() callback
and return the callback's return value. But the return type of
check_consistency() is bool. So __fscache_check_consistency()
return 1 if the cache is inconsistent. This is inconsistent with
the document.

Signed-off-by: Yan, Zheng 
Acked-by: David Howells

FS-Cache: wake write waiter after invalidating writes

2016-06-01T08:29:09+00:00

Signed-off-by: Yan, Zheng 
Acked-by: David Howells