linux-toradex.git/fs/ext2/file.c, branch v4.4.77

ext2: Add locking for DAX faults

2015-10-19T12:40:54+00:00

Add locking to ensure that DAX faults are isolated from ext2 operations
that modify the data blocks allocation for an inode.  This is intended to
be analogous to the work being done in XFS by Dave Chinner:

http://www.spinics.net/lists/linux-fsdevel/msg90260.html

Compared with XFS the ext2 case is greatly simplified by the fact that ext2
already allocates and zeros new blocks before they are returned as part of
ext2_get_block(), so DAX doesn't need to worry about getting unmapped or
unwritten buffer heads.

This means that the only work we need to do in ext2 is to isolate the DAX
faults from inode block allocation changes.  I believe this just means that
we need to isolate the DAX faults from truncate operations.

The newly introduced dax_sem is intended to replicate the protection
offered by i_mmaplock in XFS.  In addition to truncate the i_mmaplock also
protects XFS operations like hole punching, fallocate down, extent
manipulation IOCTLS like xfs_ioc_space() and extent swapping.  Truncate is
the only one of these operations supported by ext2.

Signed-off-by: Ross Zwisler 
Signed-off-by: Jan Kara

ext2: huge page fault support

2015-09-08T22:35:28+00:00

Use DAX to provide support for huge pages.

Signed-off-by: Matthew Wilcox 
Cc: Hillf Danton 
Cc: "Kirill A. Shutemov" 
Cc: Theodore Ts'o 
Cc: Jan Kara 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

dax: move DAX-related functions to a new header

2015-09-08T22:35:28+00:00

In order to handle the !CONFIG_TRANSPARENT_HUGEPAGES case, we need to
return VM_FAULT_FALLBACK from the inlined dax_pmd_fault(), which is
defined in linux/mm.h.  Given that we don't want to include 
in , the easiest solution is to move the DAX-related
functions to a new header, .  We could also have moved
VM_FAULT_* definitions to a new header, or a different header that isn't
quite such a boil-the-ocean header as , but this felt like
the best option.

Signed-off-by: Matthew Wilcox 
Cc: Hillf Danton 
Cc: "Kirill A. Shutemov" 
Cc: Theodore Ts'o 
Cc: Jan Kara 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

dax: don't abuse get_block mapping for endio callbacks

2015-06-03T23:18:18+00:00

dax_fault() currently relies on the get_block callback to attach an
io completion callback to the mapping buffer head so that it can
run unwritten extent conversion after zeroing allocated blocks.

Instead of this hack, pass the conversion callback directly into
dax_fault() similar to the get_block callback. When the filesystem
allocates unwritten extents, it will set the buffer_unwritten()
flag, and hence the dax_fault code can call the completion function
in the contexts where it is necessary without overloading the
mapping buffer head.

Note: The changes to ext4 to use this interface are suspect at best.
In fact, the way ext4 did this end_io assignment in the first place
looks suspect because it only set a completion callback when there
wasn't already some other write() call taking place on the same
inode. The ext4 end_io code looks rather intricate and fragile with
all it's reference counting and passing to different contexts for
modification via inode private pointers that aren't protected by
locks...

Signed-off-by: Dave Chinner 
Acked-by: Jan Kara 
Signed-off-by: Dave Chinner

Merge branch 'akpm' (patches from Andrew)

2015-04-15T23:39:15+00:00

Merge second patchbomb from Andrew Morton:

 - the rest of MM

 - various misc bits

 - add ability to run /sbin/reboot at reboot time

 - printk/vsprintf changes

 - fiddle with seq_printf() return value

* akpm: (114 commits)
  parisc: remove use of seq_printf return value
  lru_cache: remove use of seq_printf return value
  tracing: remove use of seq_printf return value
  cgroup: remove use of seq_printf return value
  proc: remove use of seq_printf return value
  s390: remove use of seq_printf return value
  cris fasttimer: remove use of seq_printf return value
  cris: remove use of seq_printf return value
  openrisc: remove use of seq_printf return value
  ARM: plat-pxa: remove use of seq_printf return value
  nios2: cpuinfo: remove use of seq_printf return value
  microblaze: mb: remove use of seq_printf return value
  ipc: remove use of seq_printf return value
  rtc: remove use of seq_printf return value
  power: wakeup: remove use of seq_printf return value
  x86: mtrr: if: remove use of seq_printf return value
  linux/bitmap.h: improve BITMAP_{LAST,FIRST}_WORD_MASK
  MAINTAINERS: CREDITS: remove Stefano Brivio from B43
  .mailmap: add Ricardo Ribalda
  CREDITS: add Ricardo Ribalda Delgado
  ...

dax: unify ext2/4_{dax,}_file_operations

2015-04-15T23:35:20+00:00

The original dax patchset split the ext2/4_file_operations because of the
two NULL splice_read/splice_write in the dax case.

In the vfs if splice_read/splice_write are NULL we then call
default_splice_read/write.

What we do here is make generic_file_splice_read aware of IS_DAX() so the
original ext2/4_file_operations can be used as is.

For write it appears that iter_file_splice_write is just fine.  It uses
the regular f_op->write(file,..) or new_sync_write(file, ...).

Signed-off-by: Boaz Harrosh 
Reviewed-by: Jan Kara 
Cc: Dave Chinner 
Cc: Matthew Wilcox 
Cc: Hugh Dickins 
Cc: Mel Gorman 
Cc: Kirill A. Shutemov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

dax: use pfn_mkwrite to update c/mtime + freeze protection

2015-04-15T23:35:20+00:00

From: Yigal Korman 

[v1]
Without this patch, c/mtime is not updated correctly when mmap'ed page is
first read from and then written to.

A new xfstest is submitted for testing this (generic/080)

[v2]
Jan Kara has pointed out that if we add the
sb_start/end_pagefault pair in the new pfn_mkwrite we
are then fixing another bug where: A user could start
writing to the page while filesystem is frozen.

Signed-off-by: Yigal Korman 
Signed-off-by: Boaz Harrosh 
Reviewed-by: Jan Kara 
Cc: Matthew Wilcox 
Cc: Dave Chinner 
Cc: Hugh Dickins 
Cc: Mel Gorman 
Cc: Kirill A. Shutemov 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

make new_sync_{read,write}() static

2015-04-12T02:29:40+00:00

All places outside of core VFS that checked ->read and ->write for being NULL or
called the methods directly are gone now, so NULL {read,write} with non-NULL
{read,write}_iter will do the right thing in all cases.

Signed-off-by: Al Viro

ext2: get rid of most mentions of XIP in ext2

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

To help people transition, accept the 'xip' mount option (and report it in
/proc/mounts), but print a message encouraging people to switch over to
the 'dax' option.

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