This patch implements filename encryption support for f2fs_lookup.

Note that, f2fs_find_entry should be outside of f2fs_(un)lock_op().

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

This patch implements filename encryption support for f2fs_readdir.

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

This patch adds encryption support in read and write paths.

Note that, in f2fs, we need to consider cleaning operation.
In cleaning procedure, we must avoid encrypting and decrypting written blocks.
So, this patch implements move_encrypted_block().

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

This patch activates the following APIs for encryption support.

The rules quoted by ext4 are:
 - An unencrypted directory may contain encrypted or unencrypted files
   or directories.
 - All files or directories in a directory must be protected using the
   same key as their containing directory.
 - Encrypted inode for regular file should not have inline_data.
 - Encrypted symlink and directory may have inline_data and inline_dentry.

This patch activates the following APIs.
1. f2fs_link              : validate context
2. f2fs_lookup            :      ''
3. f2fs_rename            :      ''
4. f2fs_create/f2fs_mkdir : inherit its dir's context
5. f2fs_direct_IO         : do buffered io for regular files
6. f2fs_open              : check encryption info
7. f2fs_file_mmap         :      ''
8. f2fs_setattr           :      ''
9. f2fs_file_write_iter   :      ''           (Called by sys_io_submit)
10. f2fs_fallocate        : do not support fcollapse
11. f2fs_evict_inode      : free_encryption_info

Signed-off-by: Michael Halcrow <mhalcrow@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch adds f2fs_sb_info and page pointers in f2fs_io_info structure.
With this change, we can reduce a lot of parameters for IO functions.

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

This patch adds f2fs_may_inline_data and f2fs_may_inline_dentry.

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

If f2fs was corrupted with missing dot dentries, it needs to recover them after
fsck.f2fs detection.

The underlying precedure is:

1. The fsck.f2fs remains F2FS_INLINE_DOTS flag in directory inode, if it detects
missing dot dentries.

2. When f2fs looks up the corrupted directory, it triggers f2fs_add_link with
proper inode numbers and their dot and dotdot names.

3. Once f2fs recovers the directory without errors, it removes F2FS_INLINE_DOTS
finally.

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

Split __set_data_blkaddr from f2fs_update_extent_cache for readability.

Additionally rename __set_data_blkaddr to set_data_blkaddr for exporting.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Fast symlink can utilize inline data flow to avoid using any
i_addr region, since we need to handle many cases such as
truncation, roll-forward recovery, and fsck/dump tools.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch removes wrong f2fs_bug_on in truncate_inline_inode.

When there is no space, it can happen a corner case where i_isze is over
MAX_INLINE_SIZE while its inode is still inline_data.

The scenario is
 1. write small data into file #A.
 2. fill the whole partition to 100%.
 3. truncate 4096 on file #A.
 4. write data at 8192 offset.
  --> f2fs_write_begin
    -> -ENOSPC = f2fs_convert_inline_page
    -> f2fs_write_failed
      -> truncate_blocks
        -> truncate_inline_inode
	  BUG_ON, since i_size is 4096.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>