f2fs: avoid to conduct roll-forward due to the remained garbage blocks

The f2fs always scans the next chain of direct node blocks.
But some garbage blocks are able to be remained due to no discard support or
SSR triggers.
This occasionally wreaks recovering wrong inodes that were used or BUG_ONs
due to reallocating node ids as follows.

When mount this f2fs image:
http://linuxtesting.org/downloads/f2fs_fault_image.zip
BUG_ON is triggered in f2fs driver (messages below are generated on
kernel 3.13.2; for other kernels output is similar):

kernel BUG at fs/f2fs/node.c:215!
 Call Trace:
 [<ffffffffa032ebad>] recover_inode_page+0x1fd/0x3e0 [f2fs]
 [<ffffffff811446e7>] ? __lock_page+0x67/0x70
 [<ffffffff81089990>] ? autoremove_wake_function+0x50/0x50
 [<ffffffffa0337788>] recover_fsync_data+0x1398/0x15d0 [f2fs]
 [<ffffffff812b9e5c>] ? selinux_d_instantiate+0x1c/0x20
 [<ffffffff811cb20b>] ? d_instantiate+0x5b/0x80
 [<ffffffffa0321044>] f2fs_fill_super+0xb04/0xbf0 [f2fs]
 [<ffffffff811b861e>] ? mount_bdev+0x7e/0x210
 [<ffffffff811b8769>] mount_bdev+0x1c9/0x210
 [<ffffffffa0320540>] ? validate_superblock+0x210/0x210 [f2fs]
 [<ffffffffa031cf8d>] f2fs_mount+0x1d/0x30 [f2fs]
 [<ffffffff811b9497>] mount_fs+0x47/0x1c0
 [<ffffffff81166e00>] ? __alloc_percpu+0x10/0x20
 [<ffffffff811d4032>] vfs_kern_mount+0x72/0x110
 [<ffffffff811d6763>] do_mount+0x493/0x910
 [<ffffffff811615cb>] ? strndup_user+0x5b/0x80
 [<ffffffff811d6c70>] SyS_mount+0x90/0xe0
 [<ffffffff8166f8d9>] system_call_fastpath+0x16/0x1b

Found by Linux File System Verification project (linuxtesting.org).

Reported-by: Andrey Tsyvarev <tsyvarev@ispras.ru>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: call redirty_page_for_writepage

This patch replace some general codes with redirty_page_for_writepage, which
can be enabled after consideration on additional procedure like counting dirty
pages appropriately.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: fix to unlock f2fs_lock at the omitted error case

If it occurs an error, we should call f2fs_unlock_op.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: make recover_inline_xattr() static

Make recover_inline_xattr() static, because this function is
used only in this file.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: atomically set inode->i_flags in f2fs_set_inode_flags()

Use set_mask_bits() to atomically set i_flags instead of clearing out the
S_IMMUTABLE, S_APPEND, etc. flags and then setting them from the
FS_IMMUTABLE_FL, FS_APPEND_FL, etc. flags, since this opens up a race
where an immutable file has the immutable flag cleared for a brief
window of time.

Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: add static to get_max_meta_blks

inline get_max_meta_blks is only used in checkpoint.c
Use standard static inline format.

Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: add available_nids to fix handling max_nid correctly

This patch introduces available_nids for alloc_nids() and fixes max_nid for
build_free_nids() and scan_nat_pages().

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