The page_follow_link_light returns NULL and its error pointer was remained
in nd->path.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This reports performance regression by Yuanhan Liu.
The basic idea was to reduce one-point mutex, but it turns out this causes
another contention like context swithes.

https://lkml.org/lkml/2015/4/21/11

Until finishing the analysis on this issue, I'd like to revert this for a while.

This reverts commit 78373b7319abdf15050af5b1632c4c8b8b398f33.

Pull fourth vfs update from Al Viro:
 "d_inode() annotations from David Howells (sat in for-next since before
  the beginning of merge window) + four assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  RCU pathwalk breakage when running into a symlink overmounting something
  fix I_DIO_WAKEUP definition
  direct-io: only inc/dec inode->i_dio_count for file systems
  fs/9p: fix readdir()
  VFS: assorted d_backing_inode() annotations
  VFS: fs/inode.c helpers: d_inode() annotations
  VFS: fs/cachefiles: d_backing_inode() annotations
  VFS: fs library helpers: d_inode() annotations
  VFS: assorted weird filesystems: d_inode() annotations
  VFS: normal filesystems (and lustre): d_inode() annotations
  VFS: security/: d_inode() annotations
  VFS: security/: d_backing_inode() annotations
  VFS: net/: d_inode() annotations
  VFS: net/unix: d_backing_inode() annotations
  VFS: kernel/: d_inode() annotations
  VFS: audit: d_backing_inode() annotations
  VFS: Fix up some ->d_inode accesses in the chelsio driver
  VFS: Cachefiles should perform fs modifications on the top layer only
  VFS: AF_UNIX sockets should call mknod on the top layer only

Pull f2fs updates from Jaegeuk Kim:
 "New features:
   - in-memory extent_cache
   - fs_shutdown to test power-off-recovery
   - use inline_data to store symlink path
   - show f2fs as a non-misc filesystem

  Major fixes:
   - avoid CPU stalls on sync_dirty_dir_inodes
   - fix some power-off-recovery procedure
   - fix handling of broken symlink correctly
   - fix missing dot and dotdot made by sudden power cuts
   - handle wrong data index during roll-forward recovery
   - preallocate data blocks for direct_io

  ... and a bunch of minor bug fixes and cleanups"

* tag 'for-f2fs-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (71 commits)
  f2fs: pass checkpoint reason on roll-forward recovery
  f2fs: avoid abnormal behavior on broken symlink
  f2fs: flush symlink path to avoid broken symlink after POR
  f2fs: change 0 to false for bool type
  f2fs: do not recover wrong data index
  f2fs: do not increase link count during recovery
  f2fs: assign parent's i_mode for empty dir
  f2fs: add F2FS_INLINE_DOTS to recover missing dot dentries
  f2fs: fix mismatching lock and unlock pages for roll-forward recovery
  f2fs: fix sparse warnings
  f2fs: limit b_size of mapped bh in f2fs_map_bh
  f2fs: persist system.advise into on-disk inode
  f2fs: avoid NULL pointer dereference in f2fs_xattr_advise_get
  f2fs: preallocate fallocated blocks for direct IO
  f2fs: enable inline data by default
  f2fs: preserve extent info for extent cache
  f2fs: initialize extent tree with on-disk extent info of inode
  f2fs: introduce __{find,grab}_extent_tree
  f2fs: split set_data_blkaddr from f2fs_update_extent_cache
  f2fs: enable fast symlink by utilizing inline data
  ...

This patch adds CP_RECOVERY to remain recovery information for checkpoint.
And, it makes sure writing checkpoint in this case.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

When f2fs_symlink was triggered and checkpoint was done before syncing its
link path, f2fs can get broken symlink like "xxx -> \0\0\0".
This incurs abnormal path_walk by VFS.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch tries to avoid broken symlink case after POR in best effort.
This results in performance regression.
But, if f2fs has inline_data and the target path is under 3KB-sized long,
the page would be stored in its inode_block, so that there would be no
performance regression.

Note that, if user wants to keep this file atomically, it needs to trigger
dir->fsync.
And, there is still a hole to produce broken symlink.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

in the f2fs_fill_super function, variable "retry" is bool type
i think that it should be set as false.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Now that no one is using rw, remove it completely.

Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>