f2fs: avoid BUG_ON when mouting corrupted image having garbage blocks

If the disk has some garbage blocks, F2FS is able to face with BUG_ON when
recovering direct node blocks.
This patch detects the error case and avoids that prior to reaching BUG_ON.

Alexey Khoroshilov addressed the potential security issues as follows.
"An ability to trigger a BUG_ON assert by mounting a crafted image is
usually considered as a local denial of service [1-3]. As far as I
understand, the reason is that some kernel data may become inconsistent
that can lead to further problems.

[1] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-3353
[2] http://www.openwall.com/lists/oss-security/2011/06/24/4
[3] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-2928
etc."

Reported-by: Andrey Tsyvarev <tsyvarev@ispras.ru>
Cc: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: introduce raw_nat_from_node_info() to simplfy codes

This patch introduce raw_nat_from_node_info() to simplfy some codes, and also
use exist function node_info_from_raw_nat() to do the same job.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: adjust free mem size to flush dentry blocks

If so many dirty dentry blocks are cached, not reached to the flush condition,
we should fall into livelock in balance_dirty_pages.
So, let's consider the mem size for the condition.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: handle inline data independently in f2fs_bmap

We'd better handle inline data case independently in f2fs_bmap().
It can reduce our handling time in f2fs_bmap().

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: clean up long variable names

This patch includes simple clean-ups to reduce unnecessary long variable names.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: pass flags field to setxattr functions

This patch passes the "flags" field to the low level setxattr functions
to use XATTR_REPLACE in the following patches.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: return errors right after checking them

This patch adds two error conditions early in the setxattr operations.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: submit bio at the reclaim path

If f2fs_write_data_page is called through the reclaim path, we should submit
the bio right away.

This patch resolves the following issue that Marc Dietrich reported.
"It took me a while to bisect a problem which causes my ARM (tegra2) netbook to
frequently stall for 5-10 seconds when I enable EXA acceleration (opentegra
experimental ddx)."
And this patch fixes that.

Reported-by: Marc Dietrich <marvin24@gmx.de>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: introduce help macro ADDRS_PER_PAGE()

Introduce help macro ADDRS_PER_PAGE() to get the number of address pointers in
direct node or inode.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: set errno when f2fs_iget failed in recover_dentry

We should set the error number correctly when we fail in recover_dentry(), so
the recover flow could stop for the reason as error number shows instead of
continuing.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: readahead multi pages of directory for performance

We have no so such readahead mechanism in ->iterate() path as the one in
->read() path, it cause low performance when we read large directory.
This patch add readahead in f2fs_readdir() for better performance.

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

Conflicts:
	fs/f2fs/dir.c

Change-Id: I2c3c4e204a32dc6486f1a04551f7db619a9e63e8
f2fs: fix to truncate inline data in inode page when setattr

Previous we do not truncate inline data in inode page when setattr, so following
case could still read the inline data which has already truncated:

1.write inline data
2.ftruncate size to 0
3.ftruncate size to max inline data size
4.read from offset 0

This patch introduces truncate_inline_data() to fix this problem.

change log from v1:
 o fix a bug and do not truncate first page data after truncate inline data.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: split grab_cache_page and wait_on_page_writeback for node pages

This patch splits grab_cache_page_write_begin into grab_cache_page and
wait_on_page_writeback for node pages.

This patch intends to enhance the latency to get node pages by alleviating
unnecessary wait_on_page_writeback.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: avoid grab_cache_page_write_begin for data pages

We don't need to wait on page writeback for these cases.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: no need to wait on page writebck to meta pages

This patch removes grab_cache_page_write_begin for meta pages.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: decrease the lock granularity during write_begin

This patch reduces the lock granularity during write_begin.
When the system is under memory pressure, it would be better to reduce
the locking time for the data pages.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: fix checkpatch warning

fix the following checkpatch warning:
WARNING: do {} while (0) macros should not be semicolon terminated

Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: add a tracepoint for f2fs_write_begin

This patch adds a tracepoint for f2fs_write_begin to trace write op of user.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: add a tracepoint for f2fs_write_end

This patch adds a tracepoint for f2fs_write_end to trace write op of user.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: add a tracepoint for f2fs_write_{meta,node,data}_page

This patch adds a tracepoint for f2fs_write_{meta,node,data}_page to trace when
page is writting out.

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