for one thing, it doesn't (and shouldn't) use anything else from dentry;
for another, on some call chains the dentry is fake and should
be eliminated completely.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This patch is intended to unify string length declarations and usage.
There are number of calls to strlen which return size_t object.
The size of this object depends on compiler if it will be bigger,
equal or even smaller than an unsigned int
Signed-off-by: NLeon Romanovsky <leon@leon.nu>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch cleans up a couple of unnecessary codes related to unused variables
and return values.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch also resolves the following warning reported by kbuild test robot.

fs/f2fs/gc.c: In function 'start_bidx_of_node':
fs/f2fs/gc.c:453:21: warning: 'bidx' may be used uninitialized in this function
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

We can directly return '0' from the function, instead of introducing a
'ret' variable.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

In function find_fsync_dnodes() - the fsync inodes gets added to the list, but
in one path suppose f2fs_iget results in error, in such case - error gets added
to the fsync inode list.
In next call to recover_data()->get_fsync_inode()
entry = list_entry(this, struct fsync_inode_entry, list);
                if (entry->inode->i_ino == ino)
This can result in "invalid access to memory" when it encounters 'error' as
entry in the fsync inode list.
So, add the fsync inode entry to the list only in case of no errors.
And, free the object at that point itself in case of issue.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Since, the memory for the object of dirty_seglist_info is allocated
using kzalloc - which returns zeroed out memory. So, there is no need
to initialize the nr_dirty values with zeroes.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

In case f2fs_iget_nowait returns error, it results in truncate_hole being
called with 'error' value as inode pointer. There is no check in truncate_hole
for valid inode, so it could result in crash due "invalid access to memory".
Avoid this by handling error condition properly.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Practically, has_not_enough_free_secs() should calculate with the numbers of
current node and directory data blocks together.
Actually the equation was implemented in need_to_flush().

So, this patch removes need_flush() and moves the equation into
has_not_enough_free_secs().
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch resolves a build warning reported by kbuild test robot.

"
fs/f2fs/segment.c: In function '__get_segment_type':
fs/f2fs/segment.c:806:1: warning: control reaches end of non-void
function [-Wreturn-type]
"
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

The new_node_page() is processed as the following procedure.

1. A new node page is allocated.
2. Set PageUptodate with proper footer information.
3. Check if there is a free space for allocation
 4.a. If there is no space, f2fs returns with -ENOSPC.
 4.b. Otherwise, go next.

In the case of step #4.a, f2fs remains a wrong node page in the page cache
with the uptodate flag.

Also, even though a new node page is allocated successfully, an error can be
occurred afterwards due to allocation failure of the other data structures.
In such a case, remove_inode_page() would be triggered, so that we have to
clear uptodate flag in truncate_node() too.

So, we should remove the uptodate flag, if allocation is failed.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

m68k allmodconfig:

fs/f2fs/data.c: In function ‘read_end_io’:
fs/f2fs/data.c:311: error: implicit declaration of function ‘prefetchw’

fs/f2fs/segment.c: In function ‘f2fs_end_io_write’:
fs/f2fs/segment.c:628: error: implicit declaration of function ‘prefetchw’
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

With user namespaces enabled building f2fs fails with:

 CC      fs/f2fs/acl.o
fs/f2fs/acl.c: In function ‘f2fs_acl_from_disk’:
fs/f2fs/acl.c:85:21: error: ‘struct posix_acl_entry’ has no member named ‘e_id’
make[2]: *** [fs/f2fs/acl.o] Error 1
make[2]: Target `__build' not remade because of errors.

e_id is a backwards compatibility field only used for file systems
that haven't been converted to use kuids and kgids.  When the posix
acl tag field is neither ACL_USER nor ACL_GROUP assigning e_id is
unnecessary.  Remove the assignment so f2fs will build with user
namespaces enabled.

Cc: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Amit Sahrawat <a.sahrawat@samsung.com>
Acked-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

In order to conserve free sections to deal with the worst-case scenarios, f2fs
should be able to freeze all the directory operations especially when there are
not enough free sections. The f2fs_balance_fs() is for this use.

When FS utilization becomes almost 100%, directory operations can be failed due
to -ENOSPC frequently, which produces some dirty node pages occasionally.

Previously, in such a case, f2fs_balance_fs() is not able to be triggered since
it is triggered only if the directory operation ends up with success.

So, this patch triggers f2fs_balance_fs() at first before handling directory
operations.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

The recovery routine should do all the time regardless of normal umount action.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Ruslan reported that f2fs hangs with an infinite loop in f2fs_sync_file():

	while (sync_node_pages(sbi, inode->i_ino, &wbc) == 0)
		f2fs_write_inode(inode, NULL);

The reason was revealed that the cold flag is not set even thought this inode is
a normal file. Therefore, sync_node_pages() skips to write node blocks since it
only writes cold node blocks.

The cold flag is stored to the node_footer in node block, and whenever a new
node page is allocated, it is set according to its file type, file or directory.

But, after sudden-power-off, when recovering the inode page, f2fs doesn't recover
its cold flag.

So, let's assign the cold flag in more right places.

One more thing:
If f2fs_write_inode() returns an error due to whatever situations, there would
be no dirty node pages so that sync_node_pages() returns zero.
(i.e., zero means nothing was written.)
Reported-by: NRuslan N. Marchenko <me@ruff.mobi>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Test Case:
[NFS Client]
ls -lR .

[NFS Server]
while [ 1 ]
do
echo 3 > /proc/sys/vm/drop_caches
done

Error on NFS Client: "No such file or directory"

When cache is dropped at the server, it results in lookup failure at the
NFS client due to non-connection with the parent. The default path is it
initiates a lookup by calculating the hash value for the name, even though
the hash values stored on the disk for "." and ".." is maintained as zero,
which results in failure from find_in_block due to not matching HASH values.
Fix up, by using the correct hashing values for these entries.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

In f2fs_statfs(), f_files should be the total number of available inodes
instead of the currently allocated inodes.
So, this patch should resolve the reported bug below.

Note that, showing 10% usage is not a bug, since f2fs reveals whole volume size
as much as possible and shows the space overhead as *used*.
This policy is fair enough with respect to other file systems.

<Reported Bug>
(loop0 is backed by 1GiB file)

$ mkfs.f2fs /dev/loop0

F2FS-tools: Ver: 1.1.0 (2012-12-11)
Info: sector size = 512
Info: total sectors = 2097152 (in 512bytes)
Info: zone aligned segment0 blkaddr: 512
Info: format successful

$ mount /dev/loop0 mnt/

$ df mnt/
Filesystem     1K-blocks  Used Available Use% Mounted on
/dev/loop0       1046528 98312    929784  10%
/home/zeta/linux-devel/mtd-bench/mnt

$ df mnt/ -i
Filesystem     Inodes   IUsed  IFree IUse% Mounted on
/dev/loop0       1 -465918 465919     - /home/zeta/linux-devel/mtd-bench/mnt

Notice IUsed is negative. Also, 10% usage on a fresh f2fs seems too
much to be correct.
Reported-and-Tested-by: NEzequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

We should guarantee not to do *scheduling while atomic*.
I found, in atomic f2fs_end_io_write(), there is a set_page_dirty() call
to deal with IO errors.

But, set_page_dirty() calls:
 -> f2fs_set_data_page_dirty()
   -> set_dirty_dir_page()
      -> cond_resched() which results in scheduling.

In order to avoid this, I'd like to remove simply set_page_dirty(),
since the page is already marked as ERROR and f2fs will be operated
as the read-only mode as well.
So, there is no recovery issue with this.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Previously, f2fs didn't track the parent inode number correctly which is stored
in each f2fs_inode. In the case of the following scenario, a bug can be occured.

Let's suppose there are one directory, "/b", and two files, "/a" and "/b/a".
 - pino of "/a" is ROOT_INO.
 - pino of "/b/a" is DIR_B_INO.

Then,
 # sync
  : The inode pages of "/a" and "/b/a" contain the parent inode numbers as
    ROOT_INO and DIR_B_INO respectively.
 # mv /a /b/a
  : The parent inode number of "/a" should be changed to DIR_B_INO, but f2fs
    didn't do that. Ref. f2fs_set_link().

In order to fix this clearly, I added i_pino in f2fs_inode_info, and whenever
it needs to be changed like in f2fs_add_link() and f2fs_set_link(), it is
updated temporarily in f2fs_inode_info.

And later, f2fs_write_inode() stores the latest information to the inode pages.
For power-off-recovery, f2fs_sync_file() triggers simply f2fs_write_inode().
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Do cleanup more for better code readability.

- Change the parameter set of f2fs_bio_alloc()
  This function should allocate a bio only since it is not something like
  f2fs_bio_init(). Instead, the caller should initialize the allocated bio.

- Introduce SECTOR_FROM_BLOCK
  This macro translates a block address to its sector address.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>
Reviewed-by: NNamjae Jeon <namjae.jeon@samsung.com>

Simplify code by providing the accessor macro to retrieve the
number of dentry slots for a given filename length.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>

Since, we anyway need to put the page after deleting entry. So, there is no
need to make same call under different conditions.
Move out the f2fs_put_page from the two conditions and call at once.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>

Since, GFP_NOFS and __GFP_ZERO is being used to set gfp_mask.
We can instead make use of already predefined macro GFP_F2FS_ZERO.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>

Since, GFP_NOFS(__GFP_WAIT) is used for allocation requests of bio in f2fs.
So, there is no chance of returning NULL from the BIO allocation.

Making the bio allocation routine for f2fs simpler.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>

The variables node_page and page_offset are initialized but never used
otherwise, so remove those unused variables.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>

In function f2fs_mkdir, err is being initialized without even checking
if there was any error in new inode creation. So, instead check the
inode error and make use of error/return condition.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>

No need to initialize  "struct f2fs_gc_kthread *gc_th = NULL",
as gc_th = NULL, will be taken care by the return values of kmalloc().
And fix codes in other places.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>

If the filesystem is mounted as read-only then return from that point itself
instead of first doing a writeout/wait and then checking for read-only
condition.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>

Since, __GFP_ZERO is used while f2fs inode allocation, so we do not
need memset for f2fs_inode_info, as this is already zeroed out.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>

print the invalid argument/value from parse_options in case of
mount failure.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>

When CONFIG_CC_OPTIMIZE_FOR_SIZE is enabled in the kernel, -Os optimisation
flag is passed to gcc for compilation, and somehow while trying to optimize
the code, compiler is might not able to see the initialisation of variable
ne struct variable inside the get_node_info() function and results into
following warning:

fs/f2fs/node.c: In function 'get_node_info':
fs/f2fs/node.c:175:3: warning: 'ne.block_addr' may be used uninitialized in
this function [-Wuninitialized]
fs/f2fs/node.c:265:24: note: 'ne.block_addr' was declared here
fs/f2fs/node.c:176:3: warning: 'ne.ino' may be used uninitialized in this
function [-Wuninitialized]
fs/f2fs/node.c:265:24: note: 'ne.ino' was declared here
fs/f2fs/node.c:177:3: warning: 'ne.version' may be used uninitialized in
this function [-Wuninitialized]
fs/f2fs/node.c:265:24: note: 'ne.version' was declared here

Hence, lets initialise the ne struct variable to zero, which will remove
this warning and also doing this does not seems to making any impact on the
code behavior.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NPankaj Kumar <pankaj.km@samsung.com>

There exist two build failures reported by Randy Dunlap as follows.

(on i386)
 a. (config-r8857)
	ERROR: "f2fs_xattr_advise_handler" [fs/f2fs/f2fs.ko] undefined!

Key configs in (config-r8857) are as follows.
 CONFIG_F2FS_FS=m
 # CONFIG_F2FS_STAT_FS is not set
 CONFIG_F2FS_FS_XATTR=y
 # CONFIG_F2FS_FS_POSIX_ACL is not set

The error was occurred due to the function location that we made a mistake.
Recently we added a new functionality for users to indicate cold files
explicitly through xattr operations (i.e., f2fs_xattr_advise_handler).

This handler should have been added in xattr.c instead of acl.c in order
to avoid an undefined operation like in this case where XATTR is set and
ACL is not set.

 b. (config-r8855)
	fs/f2fs/file.c: In function 'f2fs_vm_page_mkwrite':
	fs/f2fs/file.c:97:2: error: implicit declaration of function
	'block_page_mkwrite_return'

Key config in (config-r8855) is CONFIG_BLOCK.

Obviously, f2fs works on top of the block device so that we should consider
carefully a sort of config dependencies.

The reason why this error was occurred was that f2fs_vm_page_mkwrite() calls
block_page_mkwrite_return() which is enalbed only if CONFIG_BLOCK is set.
Reported-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>
Acked-by: NRandy Dunlap <rdunlap@xenotime.net>

As pointed out by Randy Dunlap, this patch removes all usage of "/**" for comment
blocks. Instead, just use "/*".
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch should resolve the bugs reported by the sparse tool.
Initial reports were written by "kbuild test robot" managed by fengguang.wu.

In my local machines, I've tested also by running:
> make C=2 CF="-D__CHECK_ENDIAN__"

Accordingly, I've found lots of warnings and bugs related to the endian
conversion. And I've fixed all at this moment.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Including <linux/version.h> is not necessary.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>

This adds Makefile and Kconfig for f2fs, and updates Makefile and Kconfig files
in the fs directory.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This moves all of the f2fs debugging files into debugfs. The files are
located in /sys/kernel/debug/f2fs/

Note, I think we are generating all of the same information in each of
the files for every unique f2fs filesystem in the machine.  This copies
the functionality that was present in the proc files, but this should be
fixed up in the future.
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
[jaegeuk.kim@samsung.com: merged 3 debugfs entries into a *status* entry]
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This adds roll-forward routines to recover fsynced data.

- F2FS uses basically roll-back model with checkpointing.

- In order to implement fsync(), there are two approaches as follows.

1. A roll-back model with checkpointing at every fsync()
 : This is a naive method, but suffers from very low performance.

2. A roll-forward model
 : F2FS adopts this model where all the fsynced data should be recovered, which
   were written after checkpointing was done. In order to figure out the data,
   F2FS keeps a "fsync" mark in direct node blocks. In addition, F2FS remains
   the location of next node block in each direct node block for reconstructing
   the chain of node blocks during the recovery.

- In order to enhance the performance, F2FS keeps a "dentry" mark also in direct
  node blocks. If this is set during the recovery, F2FS replays adding a dentry.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This adds on-demand and background cleaning functions.

- The basic background cleaning policy is trying to do cleaning jobs as much as
  possible whenever the system is idle. Once the background cleaning is done,
  the cleaner sleeps an amount of time not to interfere with VFS calls. The time
  is dynamically adjusted according to the status of whole segments, which is
  decreased when the following conditions are satisfied.

  . GC is not conducted currently, and
  . IO subsystem is idle by checking the number of requets in bdev's request
     list, and
  . There are enough dirty segments.

  Otherwise, the time is increased incrementally until to the maximum time.
  Note that, min and max times are 10 secs and 30 secs by default.

- F2FS adopts a default victim selection policy where background cleaning uses
  a cost-benefit algorithm, while on-demand cleaning uses a greedy algorithm.

- The method of moving data during the cleaning is slightly different between
  background and on-demand cleaning schemes. In the case of background cleaning,
  F2FS loads the data, and marks them as dirty. Then, F2FS expects that the data
  will be moved by flusher or VM. In the case of on-demand cleaning, F2FS should
  move the data right away.

- In order to identify valid blocks in a victim segment, F2FS scans the bitmap
  of the segment managed as an SIT entry.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>