linux.git/fs/Kconfig, branch v4.5

dax: re-enable dax pmd mappings

2016-01-16T01:56:32+00:00

Now that the get_user_pages() path knows how to handle dax-pmd mappings,
remove the protections that disabled dax-pmd support.

Tests available from github.com/pmem/ndctl:

    make TESTS="lib/test-dax.sh lib/test-mmap.sh" check

Signed-off-by: Dan Williams 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'locks-v4.5-1' of git://git.samba.org/jlayton/linux

2016-01-12T23:46:17+00:00

Pull file locking updates from Jeff Layton:
 "File locking related changes for v4.5 (pile #1)

  Highlights:
   - new Kconfig option to allow disabling mandatory locking (which is
     racy anyway)
   - new tracepoints for setlk and close codepaths
   - fix for a long-standing bug in code that handles races between
     setting a POSIX lock and close()"

* tag 'locks-v4.5-1' of git://git.samba.org/jlayton/linux:
  locks: rename __posix_lock_file to posix_lock_inode
  locks: prink more detail when there are leaked locks
  locks: pass inode pointer to locks_free_lock_context
  locks: sprinkle some tracepoints around the file locking code
  locks: don't check for race with close when setting OFD lock
  locks: fix unlock when fcntl_setlk races with a close
  fs: make locks.c explicitly non-modular
  locks: use list_first_entry_or_null()
  locks: Don't allow mounts in user namespaces to enable mandatory locking
  locks: Allow disabling mandatory locking at compile time

dax: disable pmd mappings

2015-11-17T07:54:45+00:00

While dax pmd mappings are functional in the nominal path they trigger
kernel crashes in the following paths:

 BUG: unable to handle kernel paging request at ffffea0004098000
 IP: [] follow_trans_huge_pmd+0x117/0x3b0
 [..]
 Call Trace:
  [] follow_page_mask+0x2d3/0x380
  [] __get_user_pages+0xe8/0x6f0
  [] get_user_pages_unlocked+0x165/0x1e0
  [] get_user_pages_fast+0xa1/0x1b0

 kernel BUG at arch/x86/mm/gup.c:131!
 [..]
 Call Trace:
  [] gup_pud_range+0x1bc/0x220
  [] get_user_pages_fast+0x124/0x1b0

 BUG: unable to handle kernel paging request at ffffea0004088000
 IP: [] copy_huge_pmd+0x159/0x350
 [..]
 Call Trace:
  [] copy_page_range+0x34c/0x9f0
  [] copy_process+0x1b7f/0x1e10
  [] _do_fork+0x91/0x590

All of these paths are interpreting a dax pmd mapping as a transparent
huge page and making the assumption that the pfn is covered by the
memmap, i.e. that the pfn has an associated struct page.  PTE mappings
do not suffer the same fate since they have the _PAGE_SPECIAL flag to
cause the gup path to fault.  We can do something similar for the PMD
path, or otherwise defer pmd support for cases where a struct page is
available.  For now, 4.4-rc and -stable need to disable dax pmd support
by default.

For development the "depends on BROKEN" line can be removed from
CONFIG_FS_DAX_PMD.

Cc: 
Cc: Jan Kara 
Cc: Dave Chinner 
Cc: Matthew Wilcox 
Cc: Kirill A. Shutemov 
Reported-by: Ross Zwisler 
Signed-off-by: Dan Williams

locks: Allow disabling mandatory locking at compile time

2015-11-16T14:49:34+00:00

Mandatory locking appears to be almost unused and buggy and there
appears no real interest in doing anything with it.  Since effectively
no one uses the code and since the code is buggy let's allow it to be
disabled at compile time.  I would just suggest removing the code but
undoubtedly that will break some piece of userspace code somewhere.

For the distributions that don't care about this piece of code
this gives a nice starting point to make mandatory locking go away.

Cc: Benjamin Coddington 
Cc: Dmitry Vyukov 
Cc: Jeff Layton 
Cc: J. Bruce Fields 
Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Jeff Layton

fs: Remove ext3 filesystem driver

2015-07-23T18:59:40+00:00

The functionality of ext3 is fully supported by ext4 driver. Major
distributions (SUSE, RedHat) already use ext4 driver to handle ext3
filesystems for quite some time. There is some ugliness in mm resulting
from jbd cleaning buffers in a dirty page without cleaning page dirty
bit and also support for buffer bouncing in the block layer when stable
pages are required is there only because of jbd. So let's remove the
ext3 driver. This saves us some 28k lines of duplicated code.

Acked-by: Theodore Ts'o 
Signed-off-by: Jan Kara

f2fs: relocate Kconfig from misc filesystems

2015-04-10T22:08:35+00:00

The f2fs has been shipped on many smartphone devices during a couple of years.
So, it is worth to relocate Kconfig into main page from misc filesystems for
developers to choose it more easily.

Signed-off-by: Jaegeuk Kim

dax: does not work correctly with virtual aliasing caches

2015-02-17T01:56:04+00:00

The DAX code accesses the underlying storage through the kernel's linear
mapping, which may not be cache-coherent with user mappings on ARM, MIPS
or SPARC.  Temporarily disable the DAX code until this problem is
resolved.

The original XIP code also had this problem, but it was never noticed.

Signed-off-by: Matthew Wilcox 
Cc: Andreas Dilger 
Cc: Boaz Harrosh 
Cc: Christoph Hellwig 
Cc: Dave Chinner 
Cc: Jan Kara 
Cc: Jens Axboe 
Cc: Kirill A. Shutemov 
Cc: Mathieu Desnoyers 
Cc: Randy Dunlap 
Cc: Ross Zwisler 
Cc: Theodore Ts'o 
Cc: Ralf Baechle 
Cc: Russell King 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

vfs,ext2: remove CONFIG_EXT2_FS_XIP and rename CONFIG_FS_XIP to CONFIG_FS_DAX

2015-02-17T01:56:04+00:00

The fewer Kconfig options we have the better.  Use the generic
CONFIG_FS_DAX to enable XIP support in ext2 as well as in the core.

Signed-off-by: Matthew Wilcox 
Cc: Andreas Dilger 
Cc: Boaz Harrosh 
Cc: Christoph Hellwig 
Cc: Dave Chinner 
Cc: Jan Kara 
Cc: Jens Axboe 
Cc: Kirill A. Shutemov 
Cc: Mathieu Desnoyers 
Cc: Randy Dunlap 
Cc: Ross Zwisler 
Cc: Theodore Ts'o 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs: Make efivarfs a pseudo filesystem, built by default with EFI

2015-01-05T14:15:58+00:00

efivars is currently enabled under MISC_FILESYSTEMS, which is decribed
as "such as filesystems that came from other operating systems".
In reality, it is a pseudo filesystem, providing access to the kernel
UEFI variable interface.

Since this is the preferred interface for accessing UEFI variables, over
the legacy efivars interface, also build it by default as a module if
CONFIG_EFI.

Signed-off-by: Leif Lindholm 
Signed-off-by: Matt Fleming

overlay filesystem

2014-10-23T22:14:38+00:00

Overlayfs allows one, usually read-write, directory tree to be
overlaid onto another, read-only directory tree.  All modifications
go to the upper, writable layer.

This type of mechanism is most often used for live CDs but there's a
wide variety of other uses.

The implementation differs from other "union filesystem"
implementations in that after a file is opened all operations go
directly to the underlying, lower or upper, filesystems.  This
simplifies the implementation and allows native performance in these
cases.

The dentry tree is duplicated from the underlying filesystems, this
enables fast cached lookups without adding special support into the
VFS.  This uses slightly more memory than union mounts, but dentries
are relatively small.

Currently inodes are duplicated as well, but it is a possible
optimization to share inodes for non-directories.

Opening non directories results in the open forwarded to the
underlying filesystem.  This makes the behavior very similar to union
mounts (with the same limitations vs. fchmod/fchown on O_RDONLY file
descriptors).

Usage:

  mount -t overlayfs overlayfs -olowerdir=/lower,upperdir=/upper/upper,workdir=/upper/work /overlay

The following cotributions have been folded into this patch:

Neil Brown :
 - minimal remount support
 - use correct seek function for directories
 - initialise is_real before use
 - rename ovl_fill_cache to ovl_dir_read

Felix Fietkau :
 - fix a deadlock in ovl_dir_read_merged
 - fix a deadlock in ovl_remove_whiteouts

Erez Zadok 
 - fix cleanup after WARN_ON

Sedat Dilek 
 - fix up permission to confirm to new API

Robin Dong 
 - fix possible leak in ovl_new_inode
 - create new inode in ovl_link

Andy Whitcroft 
 - switch to __inode_permission()
 - copy up i_uid/i_gid from the underlying inode

AV:
 - ovl_copy_up_locked() - dput(ERR_PTR(...)) on two failure exits
 - ovl_clear_empty() - one failure exit forgetting to do unlock_rename(),
   lack of check for udir being the parent of upper, dropping and regaining
   the lock on udir (which would require _another_ check for parent being
   right).
 - bogus d_drop() in copyup and rename [fix from your mail]
 - copyup/remove and copyup/rename races [fix from your mail]
 - ovl_dir_fsync() leaving ERR_PTR() in ->realfile
 - ovl_entry_free() is pointless - it's just a kfree_rcu()
 - fold ovl_do_lookup() into ovl_lookup()
 - manually assigning ->d_op is wrong.  Just use ->s_d_op.
 [patches picked from Miklos]:
 * copyup/remove and copyup/rename races
 * bogus d_drop() in copyup and rename

Also thanks to the following people for testing and reporting bugs:

  Jordi Pujol 
  Andy Whitcroft 
  Michal Suchanek 
  Felix Fietkau 
  Erez Zadok 
  Randy Dunlap 

Signed-off-by: Miklos Szeredi