linux.git/fs/ext2/super.c, branch v4.8

ext2: Add alignment check for DAX mount

2016-05-17T06:44:12+00:00

When a partition is not aligned by 4KB, mount -o dax succeeds,
but any read/write access to the filesystem fails, except for
metadata update.

Call bdev_dax_supported() to perform proper precondition checks
which includes this partition alignment check.

Signed-off-by: Toshi Kani 
Reviewed-by: Jan Kara 
Cc: Jan Kara 
Cc: Dan Williams 
Cc: Ross Zwisler 
Cc: Christoph Hellwig 
Cc: Boaz Harrosh 
Signed-off-by: Vishal Verma

ext2: convert to mbcache2

2016-02-22T16:56:38+00:00

The conversion is generally straightforward. We convert filesystem from
a global cache to per-fs one. Similarly to ext4 the tricky part is that
xattr block corresponding to found mbcache entry can get freed before we
get buffer lock for that block. So we have to check whether the entry is
still valid after getting the buffer lock.

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

kmemcg: account certain kmem allocations to memcg

2016-01-15T00:00:49+00:00

Mark those kmem allocations that are known to be easily triggered from
userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to
memcg.  For the list, see below:

 - threadinfo
 - task_struct
 - task_delay_info
 - pid
 - cred
 - mm_struct
 - vm_area_struct and vm_region (nommu)
 - anon_vma and anon_vma_chain
 - signal_struct
 - sighand_struct
 - fs_struct
 - files_struct
 - fdtable and fdtable->full_fds_bits
 - dentry and external_name
 - inode for all filesystems. This is the most tedious part, because
   most filesystems overwrite the alloc_inode method.

The list is far from complete, so feel free to add more objects.
Nevertheless, it should be close to "account everything" approach and
keep most workloads within bounds.  Malevolent users will be able to
breach the limit, but this was possible even with the former "account
everything" approach (simply because it did not account everything in
fact).

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Vladimir Davydov 
Acked-by: Johannes Weiner 
Acked-by: Michal Hocko 
Cc: Tejun Heo 
Cc: Greg Thelen 
Cc: Christoph Lameter 
Cc: Pekka Enberg 
Cc: David Rientjes 
Cc: Joonsoo Kim 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ext2, ext4: warn when mounting with dax enabled

2015-11-16T17:43:54+00:00

Similar to XFS warn when mounting DAX while it is still considered under
development.  Also, aspects of the DAX implementation, for example
synchronization against multiple faults and faults causing block
allocation, depend on the correct implementation in the filesystem.  The
maturity of a given DAX implementation is filesystem specific.

Cc: 
Cc: "Theodore Ts'o" 
Cc: Matthew Wilcox 
Cc: linux-ext4@vger.kernel.org
Cc: Kirill A. Shutemov 
Reported-by: Dave Chinner 
Acked-by: Jan Kara 
Signed-off-by: Dan Williams

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

vfs, writeback: replace FS_CGROUP_WRITEBACK with SB_I_CGROUPWB

2015-06-17T18:47:39+00:00

FS_CGROUP_WRITEBACK indicates whether a file_system_type supports
cgroup writeback; however, different super_blocks of the same
file_system_type may or may not support cgroup writeback depending on
filesystem options.  This patch replaces FS_CGROUP_WRITEBACK with a
per-super_block flag.

super_block->s_flags carries some internal flags in the high bits but
it's exposd to userland through uapi header and running out of space
anyway.  This patch adds a new field super_block->s_iflags to carry
kernel-internal flags.  It is currently only used by the new
SB_I_CGROUPWB flag whose concatenated and abbreviated name is for
consistency with other super_block flags.

ext2_fill_super() is updated to set SB_I_CGROUPWB.

v2: Added super_block->s_iflags instead of stealing another high bit
    from sb->s_flags as suggested by Christoph and Jan.

Signed-off-by: Tejun Heo 
Cc: Alexander Viro 
Cc: linux-fsdevel@vger.kernel.org
Cc: Christoph Hellwig 
Cc: Jan Kara 
Cc: linux-ext4@vger.kernel.org
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

ext2: enable cgroup writeback support

2015-06-02T14:38:04+00:00

Writeback now supports cgroup writeback and the generic writeback,
buffer, libfs, and mpage helpers that ext2 uses are all updated to
work with cgroup writeback.

This patch enables cgroup writeback for ext2 by adding
FS_CGROUP_WRITEBACK to its ->fs_flags.

Signed-off-by: Tejun Heo 
Cc: Jens Axboe 
Cc: Jan Kara 
Cc: linux-ext4@vger.kernel.org
Signed-off-by: Jens Axboe

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

ext2: remove xip.c and xip.h

2015-02-17T01:56:03+00:00

These files are now empty, so delete them

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