- iget/iput flow in the dentry recovery process

1. *dir* = f2fs_iget
2. set FI_DELAY_IPUT to *dir*
3. add *dir* to the dirty_dir_list
		   - __f2fs_add_link
		     - recover_dentry)
4. iput *dir* by remove_dirty_dir_inode
		   - sync_dirty_dir_inodes
		     - write_chekcpoint

If *dir*'s i_count is not 1 (i.e., root dir), remove_dirty_dir_inode is called
later and then iput is triggered again due to the FI_DELAY_IPUT flag.
So, let's unset the flag properly once iput is triggered.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

The error scenario is:
1. create /a
(1.a link /a /b)
2. sync
3. unlinke /a
4. create /a
5. fsync /a
6. Sudden power-off

When the f2fs recovers the fsynced dentry, /a, we discover an exsiting dentry at
f2fs_find_entry() in recover_dentry().

In such the case, we should unlink the existing dentry and its inode
and then recover newly created dentry.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

If there remains some unwritten blocks from the recovery, we should not call
iput on that directory inode.
Otherwise, we can loose some dentry blocks after the recovery.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

when there is an error from kthread_run, then return proper error
rather than returning -ENOMEM.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

There are various functions with common code which could be separated
out to make common routines. So, made new routines and in order to
retain the same call path and no major changes, written some macros
to access those routines.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

There is no need to initialize few pointers in f2fs_parent_dir
as the values are not checked and instead directly initialized
values are used.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

Some, counters are needed only for the statistical information
while debugging.
So, those can be controlled using CONFIG_F2FS_STAT_FS,
pushing the usage for few variables under this flag.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

The on-disk block address is defined as __le32, but in-memory block address,
block_t, does as u64.

Let's synchronize them to 32 bits.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

There is an error path where "dir" is an ERR_PTR.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

Use the following helper function committed by Al.

commit 7de9c6ee
Author: Al Viro <viro@zeniv.linux.org.uk>
Date:   Sat Oct 23 11:11:40 2010 -0400

    new helper: ihold()

...
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

If -ENOSPC is met during f2fs_link, we should not make the inode as bad.
The inode is still alive.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

This patch adds error handling codes of check_index_in_prev_nodes and its
caller, do_recover_data.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

This patch fixes the following deadlock bug during the recovery.

INFO: task mount:1322 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
mount           D ffffffff81125870     0  1322   1266 0x00000000
 ffff8801207e39d8 0000000000000046 ffff88012ab1dee0 0000000000000046
 ffff8801207e3a08 ffff880115903f40 ffff8801207e3fd8 ffff8801207e3fd8
 ffff8801207e3fd8 ffff880115903f40 ffff8801207e39d8 ffff88012fc94520
Call Trace:
[<ffffffff81125870>] ? __lock_page+0x70/0x70
[<ffffffff816a92d9>] schedule+0x29/0x70
[<ffffffff816a93af>] io_schedule+0x8f/0xd0
[<ffffffff8112587e>] sleep_on_page+0xe/0x20
[<ffffffff816a649a>] __wait_on_bit_lock+0x5a/0xc0
[<ffffffff81125867>] __lock_page+0x67/0x70
[<ffffffff8106c7b0>] ? autoremove_wake_function+0x40/0x40
[<ffffffff81126857>] find_lock_page+0x67/0x80
[<ffffffff8112698f>] find_or_create_page+0x3f/0xb0
[<ffffffffa03901a8>] ? sync_inode_page+0xa8/0xd0 [f2fs]
[<ffffffffa038fdf7>] get_node_page+0x67/0x180 [f2fs]
[<ffffffffa039818b>] recover_fsync_data+0xacb/0xff0 [f2fs]
[<ffffffff816aaa1e>] ? _raw_spin_unlock+0x3e/0x40
[<ffffffffa0389634>] f2fs_fill_super+0x7d4/0x850 [f2fs]
[<ffffffff81184cf9>] mount_bdev+0x1c9/0x210
[<ffffffffa0388e60>] ? validate_superblock+0x180/0x180 [f2fs]
[<ffffffffa0387635>] f2fs_mount+0x15/0x20 [f2fs]
[<ffffffff81185a13>] mount_fs+0x43/0x1b0
[<ffffffff81145ba0>] ? __alloc_percpu+0x10/0x20
[<ffffffff811a0796>] vfs_kern_mount+0x76/0x120
[<ffffffff811a2cb7>] do_mount+0x237/0xa10
[<ffffffff81140b9b>] ? strndup_user+0x5b/0x80
[<ffffffff811a3520>] SyS_mount+0x90/0xe0
[<ffffffff816b3502>] system_call_fastpath+0x16/0x1b

The bug is triggered when check_index_in_prev_nodes tries to get the direct
node page by calling get_node_page.
At this point, if the direct node page is already locked by get_dnode_of_data,
its caller, we got a deadlock condition.

This patch adds additional condition check for the reuse of locked direct node
pages prior to the get_node_page call.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

While an orphan inode has zero link_count, f2fs_gc is able to select the inode
for foreground gc.

- f2fs_gc
 - do_garbage_collect
   - gc_data_segment
     : f2fs_iget is failed
     : get_valid_blocks() != 0, so that retry
--> here we got the infinite loop.

This patch resolved this issue.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

Introduce a simple macro function for readability.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

This patch tries to avoid the following deadlock condition of which the reclaim
path can trigger f2fs_balance_fs again.

=================================
[ INFO: inconsistent lock state ]
---------------------------------
inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage.
kswapd0/41 [HC0[0]:SC0[0]:HE1:SE1] takes:
 (&sbi->gc_mutex){+.+.?.}, at: f2fs_balance_fs+0xe6/0x100 [f2fs]
{RECLAIM_FS-ON-W} state was registered at:
  [<ffffffff810aa5a9>] mark_held_locks+0xb9/0x140
  [<ffffffff810aae85>] lockdep_trace_alloc+0x85/0xf0
  [<ffffffff8113ab2c>] __alloc_pages_nodemask+0x7c/0x9b0
  [<ffffffff81175aa8>] alloc_pages_current+0xb8/0x180
  [<ffffffff811319cf>] __page_cache_alloc+0xaf/0xd0
  [<ffffffff8113225c>] find_or_create_page+0x4c/0xb0
  [<ffffffffa021359e>] find_data_page+0x14e/0x210 [f2fs]
  [<ffffffffa021161b>] f2fs_gc+0x9eb/0xd90 [f2fs]
  [<ffffffffa0218fae>] f2fs_balance_fs+0xee/0x100 [f2fs]
  [<ffffffffa020848c>] f2fs_setattr+0x6c/0x200 [f2fs]
  [<ffffffff811ae51b>] notify_change+0x1db/0x3a0
  [<ffffffff8118fbd0>] do_truncate+0x60/0xa0
  [<ffffffff8118fd95>] vfs_truncate+0x185/0x1b0
  [<ffffffff8118fe1c>] do_sys_truncate+0x5c/0xa0
  [<ffffffff8118ffee>] SyS_truncate+0xe/0x10
  [<ffffffff816e2b42>] system_call_fastpath+0x16/0x1b
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

If we met an error during the dentry recovery, we should not conduct checkpoint.
Otherwise, some errorneous dentry blocks overwrites the existing blocks that
contain the remaining recovery information.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

If we got an error after lock_page, we should unlock it before exit.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

The allocated page used by the recovery is not on HIGHMEM, so that we don't
need to use kmap/kunmap.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

Few things can be changed in the default mkwrite function
1) Make file_update_time at the start before acquiring any lock
2) the condition page_offset(page) >= i_size_read(inode) should be
 changed to page_offset(page) > i_size_read
3) Move wait_on_page_writeback.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

We can do this, since now we use a global mutex, f2fs_stat_mutex to protect its
list operations.
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
[Jaegeuk Kim: add description]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

Code cleanup without behavior changed.
Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

Majianpeng reported a lockdep splat for f2fs. It turns out mutex_lock_all()
acquires an array of locks (in global/local lock style).

Any such operation is always serialized using cp_mutex, therefore there is no
fs_lock[] lock-order issue; tell lockdep about this using the
mutex_lock_nest_lock() primitive.
Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

This patch adds some trivial debugging messages in the recovery process.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

I found a bug when testing power-off-recovery as follows.

[Bug Scenario]
1. create a file
2. fsync the file
3. reboot w/o any sync
4. try to recover the file
 - found its fsync mark
 - found its dentry mark
   : try to recover its dentry
    - get its file name
    - get its parent inode number
     : here we got zero value

The reason why we get the wrong parent inode number is that we didn't
synchronize the inode page with its newly created inode information perfectly.

Especially, previous f2fs stores fi->i_pino and writes it to the cached
node page in a wrong order, which incurs the zero-valued i_pino during the
recovery.

So, this patch modifies the creation flow to fix the synchronization order of
inode page with its inode.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

This patch is for passing a locked node page to get_dnode_of_data.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

If get_dnode_of_data gets a locked node page, let's skip redundant
get_node_page calls.
This is for the futher enhancement.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

This por_doing check is totally not related to the recovery process.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

During the dentry recovery routine, recover_inode() triggers __f2fs_add_link
with its directory inode.

In the following scenario, a bug is captured.
 1. dir = f2fs_iget(pino)
 2. __f2fs_add_link(dir, name)
 3. iput(dir)
  -> f2fs_evict_inode() faces with BUG_ON(atomic_read(fi->dirty_dents))

Kernel BUG at ffffffffa01c0676 [verbose debug info unavailable]
[<ffffffffa01c0676>] f2fs_evict_inode+0x276/0x300 [f2fs]
Call Trace:
 [<ffffffff8118ea00>] evict+0xb0/0x1b0
 [<ffffffff8118f1c5>] iput+0x105/0x190
 [<ffffffffa01d2dac>] recover_fsync_data+0x3bc/0x1070 [f2fs]
 [<ffffffff81692e8a>] ? io_schedule+0xaa/0xd0
 [<ffffffff81690acb>] ? __wait_on_bit_lock+0x7b/0xc0
 [<ffffffff8111a0e7>] ? __lock_page+0x67/0x70
 [<ffffffff81165e21>] ? kmem_cache_alloc+0x31/0x140
 [<ffffffff8118a502>] ? __d_instantiate+0x92/0xf0
 [<ffffffff812a949b>] ? security_d_instantiate+0x1b/0x30
 [<ffffffff8118a5b4>] ? d_instantiate+0x54/0x70

This means that we should flush all the dentry pages between iget and iput().
But, during the recovery routine, it is unallowed due to consistency, so we
have to wait the whole recovery process.
And then, write_checkpoint flushes all the dirty dentry blocks, and nicely we
can put the stale dir inodes from the dirty_dir_inode_list.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

The reason of using sbi->por_doing is to alleviate data writes during the
recovery.
The find_fsync_dnodes() produces some dirty dentry pages, so we should
cover it too with sbi->por_doing.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

We don't need to assign a value redundantly.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

In get_lock_data_page, if there is a data race between get_dnode_of_data for
node and grab_cache_page for data, f2fs is able to face with the following
BUG_ON(dn.data_blkaddr == NEW_ADDR).

kernel BUG at /home/zeus/f2fs_test/src/fs/f2fs/data.c:251!
 [<ffffffffa044966c>] get_lock_data_page+0x1ec/0x210 [f2fs]
Call Trace:
 [<ffffffffa043b089>] f2fs_readdir+0x89/0x210 [f2fs]
 [<ffffffff811a0920>] ? fillonedir+0x100/0x100
 [<ffffffff811a0920>] ? fillonedir+0x100/0x100
 [<ffffffff811a07f8>] vfs_readdir+0xb8/0xe0
 [<ffffffff811a0b4f>] sys_getdents+0x8f/0x110
 [<ffffffff816d7999>] system_call_fastpath+0x16/0x1b

This bug is able to be occurred when the block address of the data block is
changed after f2fs_put_dnode().
In order to avoid that, this patch fixes the lock order of node and data
blocks in which the node block lock is covered by the data block lock.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

Currently f2fs recovers the dentry of fsynced files.
When power-off-recovery is conducted, this newly recovered inode should increase
node block count as well as inode block count.

This patch resolves this inconsistency that results in:

1. create a file
2. write data
3. fsync
4. reboot without sync
5. mount and recover the file
6. node block count is 1 and inode block count is 2
 : fall into the inconsistent state
7. unlink the file
 : trigger the following BUG_ON

------------[ cut here ]------------
kernel BUG at /home/zeus/f2fs_test/src/fs/f2fs/f2fs.h:716!
Call Trace:
 [<ffffffffa0344100>] ? get_node_page+0x50/0x1a0 [f2fs]
 [<ffffffffa0344bfc>] remove_inode_page+0x8c/0x100 [f2fs]
 [<ffffffffa03380f0>] ? f2fs_evict_inode+0x180/0x2d0 [f2fs]
 [<ffffffffa033812e>] f2fs_evict_inode+0x1be/0x2d0 [f2fs]
 [<ffffffff811c7a67>] evict+0xa7/0x1a0
 [<ffffffff811c82b5>] iput+0x105/0x190
 [<ffffffff811c2b30>] d_kill+0xe0/0x120
 [<ffffffff811c2c57>] dput+0xe7/0x1e0
 [<ffffffff811acc3d>] __fput+0x19d/0x2d0
 [<ffffffff811acd7e>] ____fput+0xe/0x10
 [<ffffffff81070645>] task_work_run+0xb5/0xe0
 [<ffffffff81002941>] do_notify_resume+0x71/0xb0
 [<ffffffff8175f14a>] int_signal+0x12/0x17
Reported-and-Tested-by: Chris Fries <C.Fries@motorola.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

do_smart_update_queue() is called when an operation (semop,
semctl(SETVAL), semctl(SETALL), ...) modified the array.  It must check
which of the sleeping tasks can proceed.

do_smart_update_queue() missed a few wakeups:
 - if a sleeping complex op was completed, then all per-semaphore queues
   must be scanned - not only those that were modified by *sops
 - if a sleeping simple op proceeded, then the global queue must be
   scanned again

And:
 - the test for "|sops == NULL) before scanning the global queue is not
   required: If the global queue is empty, then it doesn't need to be
   scanned - regardless of the reason for calling do_smart_update_queue()

The patch is not optimized, i.e.  even completing a wait-for-zero
operation causes a rescan.  This is done to keep the patch as simple as
possible.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull NFS client bugfixes from Trond Myklebust:

 - Stable fix to prevent an rpc_task wakeup race
 - Fix a NFSv4.1 session drain deadlock
 - Fix a NFSv4/v4.1 mount regression when not running rpc.gssd
 - Ensure auth_gss pipe detection works in namespaces
 - Fix SETCLIENTID fallback if rpcsec_gss is not available

* tag 'nfs-for-3.10-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFS: Fix SETCLIENTID fallback if GSS is not available
  SUNRPC: Prevent an rpc_task wakeup race
  NFSv4.1 Fix a pNFS session draining deadlock
  SUNRPC: Convert auth_gss pipe detection to work in namespaces
  SUNRPC: Faster detection if gssd is actually running
  SUNRPC: Fix a bug in gss_create_upcall

Pull amd64 edac fix from Borislav Petkov:
 "A sysfs file permissions correction"

* tag 'edac_fixes_for_3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp:
  amd64_edac: Fix bogus sysfs file permissions

Pull parisc fixes from Helge Deller:
 "This time we made the kernel- and interruption stack allocation
  reentrant which fixed some strange kernel crashes (specifically
  protection ID traps).

  Furthemore this patchset fixes the interrupt stack in UP and SMP
  configurations by using native locking instructions.  And finally
  usage of floating point calculations on parisc were disabled in the
  MPILIB."

* 'parisc-for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: fix irq stack on UP and SMP
  parisc/superio: Use module_pci_driver to register driver
  parisc: make interrupt and interruption stack allocation reentrant
  parisc: show number of FPE and unaligned access handler calls in /proc/interrupts
  parisc: add additional parisc git tree to MAINTAINERS file
  parisc: use PAGE_SHIFT instead of hardcoded value 12 in pacache.S
  parisc: add rp5470 entry to machine database
  MPILIB: disable usage of floating point registers on parisc

Pull xfs fixes from Ben Myers:
 "Here are fixes for corruption on 512 byte filesystems, a rounding
  error, a use-after-free, some flags to fix lockdep reports, and
  several fixes related to CRCs.  We have a somewhat larger post -rc1
  queue than usual due to fixes related to the CRC feature we merged for
  3.10:

   - Fix for corruption with FSX on 512 byte blocksize filesystems
   - Fix rounding error in xfs_free_file_space
   - Fix use-after-free with extent free intents
   - Add several missing KM_NOFS flags to fix lockdep reports
   - Several fixes for CRC related code"

* tag 'for-linus-v3.10-rc3' of git://oss.sgi.com/xfs/xfs:
  xfs: remote attribute lookups require the value length
  xfs: xfs_attr_shortform_allfit() does not handle attr3 format.
  xfs: xfs_da3_node_read_verify() doesn't handle XFS_ATTR3_LEAF_MAGIC
  xfs: fix missing KM_NOFS tags to keep lockdep happy
  xfs: Don't reference the EFI after it is freed
  xfs: fix rounding in xfs_free_file_space
  xfs: fix sub-page blocksize data integrity writes

Pull bettery fixes from Anton Vorontsov:
 "Last minute one-liners: wrong kfree usage fix, module alias fixup and
  kconfig adjustments"

* tag 'for-v3.10-fixes' of git://git.infradead.org/battery-2.6:
  pm2301_charger: Fix module alias prefix
  wm831x_backup: Fix wrong kfree call for devdata->backup.name
  bq27x00: Fix I2C dependency in KConfig
  lp8788-charger: Fix kconfig dependency