linux.git/fs/nilfs2/file.c, branch v4.2

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

mm: drop vm_ops->remap_pages and generic_file_remap_pages() stub

2015-02-10T22:30:30+00:00

Nobody uses it anymore.

[akpm@linux-foundation.org: fix filemap_xip.c]
Signed-off-by: Kirill A. Shutemov 
Cc: Wu Fengguang 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

nilfs2: avoid duplicate segment construction for fsync()

2014-12-11T01:41:16+00:00

This patch removes filemap_write_and_wait_range() from nilfs_sync_file(),
because it triggers a data segment construction by calling
nilfs_writepages() with WB_SYNC_ALL.  A data segment construction does not
remove the inode from the i_dirty list and it does not clear the
NILFS_I_DIRTY flag.  Therefore nilfs_inode_dirty() still returns true,
which leads to an unnecessary duplicate segment construction in
nilfs_sync_file().

A call to filemap_write_and_wait_range() is not needed, because NILFS2
does not rely on the generic writeback mechanisms.  Instead it implements
its own mechanism to collect all dirty pages and write them into segments.
 It is more efficient to initiate the segment construction directly in
nilfs_sync_file() without the detour over filemap_write_and_wait_range().

Additionally the lock of i_mutex is not needed, because all code blocks
that are protected by i_mutex are also protected by a NILFS transaction:

  Function                i_mutex     nilfs_transaction
  ------------------------------------------------------
  nilfs_ioctl_setflags:   yes         yes
  nilfs_fiemap:           yes         no
  nilfs_write_begin:      yes         yes
  nilfs_write_end:        yes         yes
  nilfs_lookup:           yes         no
  nilfs_create:           yes         yes
  nilfs_link:             yes         yes
  nilfs_mknod:            yes         yes
  nilfs_symlink:          yes         yes
  nilfs_mkdir:            yes         yes
  nilfs_unlink:           yes         yes
  nilfs_rmdir:            yes         yes
  nilfs_rename:           yes         yes
  nilfs_setattr:          yes         yes

For nilfs_lookup() i_mutex is held for the parent directory, to protect it
from modification.  The segment construction does not modify directory
inodes, so no lock is needed.

nilfs_fiemap() reads the block layout on the disk, by using
nilfs_bmap_lookup_contig(). This is already protected by bmap->b_sem.

Signed-off-by: Andreas Rohner 
Signed-off-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

nilfs2: add missing blkdev_issue_flush() to nilfs_sync_fs()

2014-10-14T00:18:20+00:00

Under normal circumstances nilfs_sync_fs() writes out the super block,
which causes a flush of the underlying block device.  But this depends
on the THE_NILFS_SB_DIRTY flag, which is only set if the pointer to the
last segment crosses a segment boundary.  So if only a small amount of
data is written before the call to nilfs_sync_fs(), no flush of the
block device occurs.

In the above case an additional call to blkdev_issue_flush() is needed.
To prevent unnecessary overhead, the new flag nilfs->ns_flushed_device
is introduced, which is cleared whenever new logs are written and set
whenever the block device is flushed.  For convenience the function
nilfs_flush_device() is added, which contains the above logic.

Signed-off-by: Andreas Rohner 
Signed-off-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

write_iter variants of {__,}generic_file_aio_write()

2014-05-06T21:38:00+00:00

Signed-off-by: Al Viro

switch simple generic_file_aio_read() users to ->read_iter()

2014-05-06T21:37:55+00:00

Signed-off-by: Al Viro

mm: implement ->map_pages for page cache

2014-04-07T23:35:53+00:00

filemap_map_pages() is generic implementation of ->map_pages() for
filesystems who uses page cache.

It should be safe to use filemap_map_pages() for ->map_pages() if
filesystem use filemap_fault() for ->fault().

Signed-off-by: Kirill A. Shutemov 
Acked-by: Linus Torvalds 
Cc: Mel Gorman 
Cc: Rik van Riel 
Cc: Andi Kleen 
Cc: Matthew Wilcox 
Cc: Dave Hansen 
Cc: Alexander Viro 
Cc: Dave Chinner 
Cc: Ning Qu 
Cc: Hugh Dickins 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2013-02-27T04:16:07+00:00

Pull vfs pile (part one) from Al Viro:
 "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
  locking violations, etc.

  The most visible changes here are death of FS_REVAL_DOT (replaced with
  "has ->d_weak_revalidate()") and a new helper getting from struct file
  to inode.  Some bits of preparation to xattr method interface changes.

  Misc patches by various people sent this cycle *and* ocfs2 fixes from
  several cycles ago that should've been upstream right then.

  PS: the next vfs pile will be xattr stuff."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
  saner proc_get_inode() calling conventions
  proc: avoid extra pde_put() in proc_fill_super()
  fs: change return values from -EACCES to -EPERM
  fs/exec.c: make bprm_mm_init() static
  ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
  ocfs2: fix possible use-after-free with AIO
  ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
  get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
  target: writev() on single-element vector is pointless
  export kernel_write(), convert open-coded instances
  fs: encode_fh: return FILEID_INVALID if invalid fid_type
  kill f_vfsmnt
  vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
  nfsd: handle vfs_getattr errors in acl protocol
  switch vfs_getattr() to struct path
  default SET_PERSONALITY() in linux/elf.h
  ceph: prepopulate inodes only when request is aborted
  d_hash_and_lookup(): export, switch open-coded instances
  9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
  9p: split dropping the acls from v9fs_set_create_acl()
  ...

new helper: file_inode(file)

2013-02-23T04:31:31+00:00

Signed-off-by: Al Viro

mm: only enforce stable page writes if the backing device requires it

2013-02-22T01:22:19+00:00

Create a helper function to check if a backing device requires stable
page writes and, if so, performs the necessary wait.  Then, make it so
that all points in the memory manager that handle making pages writable
use the helper function.  This should provide stable page write support
to most filesystems, while eliminating unnecessary waiting for devices
that don't require the feature.

Before this patchset, all filesystems would block, regardless of whether
or not it was necessary.  ext3 would wait, but still generate occasional
checksum errors.  The network filesystems were left to do their own
thing, so they'd wait too.

After this patchset, all the disk filesystems except ext3 and btrfs will
wait only if the hardware requires it.  ext3 (if necessary) snapshots
pages instead of blocking, and btrfs provides its own bdi so the mm will
never wait.  Network filesystems haven't been touched, so either they
provide their own stable page guarantees or they don't block at all.
The blocking behavior is back to what it was before 3.0 if you don't
have a disk requiring stable page writes.

Here's the result of using dbench to test latency on ext2:

3.8.0-rc3:
 Operation      Count    AvgLat    MaxLat
 ----------------------------------------
 WriteX        109347     0.028    59.817
 ReadX         347180     0.004     3.391
 Flush          15514    29.828   287.283

Throughput 57.429 MB/sec  4 clients  4 procs  max_latency=287.290 ms

3.8.0-rc3 + patches:
 WriteX        105556     0.029     4.273
 ReadX         335004     0.005     4.112
 Flush          14982    30.540   298.634

Throughput 55.4496 MB/sec  4 clients  4 procs  max_latency=298.650 ms

As you can see, the maximum write latency drops considerably with this
patch enabled.  The other filesystems (ext3/ext4/xfs/btrfs) behave
similarly, but see the cover letter for those results.

Signed-off-by: Darrick J. Wong 
Acked-by: Steven Whitehouse 
Reviewed-by: Jan Kara 
Cc: Adrian Hunter 
Cc: Andy Lutomirski 
Cc: Artem Bityutskiy 
Cc: Joel Becker 
Cc: Mark Fasheh 
Cc: Jens Axboe 
Cc: Eric Van Hensbergen 
Cc: Ron Minnich 
Cc: Latchesar Ionkov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds