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>

This implements xattr and acl functionalities.

- F2FS uses a node page to contain use extended attributes.
Signed-off-by: NChangman Lee <cm224.lee@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

this adds core functions to find, add, delete, and link dentries.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This adds inode operations for directory, symlink, and special inodes.
Signed-off-by: NChangman Lee <cm224.lee@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This adds core functions to get, read, write, and evict an inode.
Signed-off-by: NChangman Lee <cm224.lee@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This adds address space operations for data.

- F2FS supports readpages(), writepages(), and direct_IO().

- Because of out-of-place writes, f2fs_direct_IO() does not write data in place.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This adds memory operations and file/file_inode operations.

- F2FS supports fallocate(), mmap(), fsync(), and basic ioctl().
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This adds specific functions not only to manage dirty/free segments, SIT pages,
a cache for SIT entries, and summary entries, but also to allocate free blocks
and write three types of pages: data, node, and meta.

- F2FS maintains three types of bitmaps in memory, which indicate free, prefree,
  and dirty segments respectively.

- The key information of an SIT entry consists of a segment number, the number
  of valid blocks in the segment, a bitmap to identify there-in valid or invalid
  blocks.

- An SIT page is composed of a certain range of SIT entries, which is maintained
  by the address space of meta_inode.

- To cache SIT entries, a simple array is used. The index for the array is the
  segment number.

- A summary entry for data contains the parent node information. A summary entry
  for node contains its node offset from the inode.

- F2FS manages information about six active logs and those summary entries in
  memory. Whenever one of them is changed, its summary entries are flushed to
  its SIT page maintained by the address space of meta_inode.

- This patch adds a default block allocation function which supports heap-based
  allocation policy.

- This patch adds core functions to write data, node, and meta pages. Since LFS
  basically produces a series of sequential writes, F2FS merges sequential bios
  with a single one as much as possible to reduce the IO scheduling overhead.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This adds specific functions to manage NAT pages, a cache for NAT entries, free
nids, direct/indirect node blocks for indexing data, and address space for node
pages.

- The key information of an NAT entry consists of a node id and a block address.

- An NAT page is composed of block addresses covered by a certain range of NAT
  entries, which is maintained by the address space of meta_inode.

- A radix tree structure is used to cache NAT entries. The index for the tree
  is a node id.

- When there is no free nid, F2FS should scan NAT entries to find new one. In
  order to avoid scanning frequently, F2FS manages a list containing a number of
  free nids in memory. Only when free nids in the list are exhausted, scanning
  process, build_free_nids(), is triggered.

- F2FS has direct and indirect node blocks for indexing data. This patch adds
  fuctions related to the node block management such as getting, allocating, and
  truncating node blocks to index data.

- In order to cache node blocks in memory, F2FS has a node_inode with an address
  space for node pages. This patch also adds the address space operations for
  node_inode.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This adds functions required by the checkpoint operations.

Basically, f2fs adopts a roll-back model with checkpoint blocks written in the
CP area. The checkpoint procedure includes as follows.

- write_checkpoint()
1. block_operations() freezes VFS calls.
2. submit cached bios.
3. flush_nat_entries() writes NAT pages updated by dirty NAT entries.
4. flush_sit_entries() writes SIT pages updated by dirty SIT entries.
5. do_checkpoint() writes,
  - checkpoint block (#0)
  - orphan inode blocks
  - summary blocks made by active logs
  - checkpoint block (copy of #0)
6. unblock_opeations()

In order to provide an address space for meta pages, f2fs_sb_info has a special
inode, namely meta_inode. This patch also adds the address space operations for
meta_inode.
Signed-off-by: NChul Lee <chur.lee@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This adds the implementation of superblock operations for f2fs, which includes
- init_f2fs_fs/exit_f2fs_fs
- f2fs_mount
- super_operations of f2fs
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This adds the following major in-memory structures in f2fs.

- f2fs_sb_info:
  contains f2fs-specific information, two special inode pointers for node and
  meta address spaces, and orphan inode management.

- f2fs_inode_info:
  contains vfs_inode and other fs-specific information.

- f2fs_nm_info:
  contains node manager information such as NAT entry cache, free nid list,
  and NAT page management.

- f2fs_node_info:
  represents a node as node id, inode number, block address, and its version.

- f2fs_sm_info:
  contains segment manager information such as SIT entry cache, free segment
  map, current active logs, dirty segment management, and segment utilization.
  The specific structures are sit_info, free_segmap_info, dirty_seglist_info,
  curseg_info.

In addition, add F2FS_SUPER_MAGIC in magic.h.
Signed-off-by: NChul Lee <chur.lee@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

The direct-IO write path already had the i_size checks in mm/filemap.c,
but it turns out the read path did not, and removing the block size
checks in fs/block_dev.c (commit bbec0270: "blkdev_max_block: make
private to fs/buffer.c") removed the magic "shrink IO to past the end of
the device" code there.

Fix it by truncating the IO to the size of the block device, like the
write path already does.

NOTE! I suspect the write path would be *much* better off doing it this
way in fs/block_dev.c, rather than hidden deep in mm/filemap.c.  The
mm/filemap.c code is extremely hard to follow, and has various
conditionals on the target being a block device (ie the flag passed in
to 'generic_write_checks()', along with a conditional update of the
inode timestamp etc).

It is also quite possible that we should treat this whole block device
size as a "s_maxbytes" issue, and try to make the logic even more
generic.  However, in the meantime this is the fairly minimal targeted
fix.

Noted by Milan Broz thanks to a regression test for the cryptsetup
reencrypt tool.
Reported-and-tested-by: NMilan Broz <mbroz@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

READ is zero so the "rw & READ" test is always false.  The intended test
was "((rw & RW_MASK) == READ)".
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The block device access simplification that avoided accessing the (racy)
block size information (commit bbec0270: "blkdev_max_block: make
private to fs/buffer.c") no longer checks the maximum block size in the
block mapping path.

That was _almost_ as simple as just removing the code entirely, because
the readers and writers all check the size of the device anyway, so
under normal circumstances it "just worked".

However, the block size may be such that the end of the device may
straddle one single buffer_head.  At which point we may still want to
access the end of the device, but the buffer we use to access it
partially extends past the end.

The 'bd_set_size()' function intentionally sets the block size to avoid
this, but mounting the device - or setting the block size by hand to
some other value - can modify that block size.

So instead, teach 'submit_bh()' about the special case of the buffer
head straddling the end of the device, and turning such an access into a
smaller IO access, avoiding the problem.

This, btw, also means that unlike before, we can now access the whole
device regardless of device block size setting.  So now, even if the
device size is only 512-byte aligned, we can read and write even the
last sector even when having a much bigger block size for accessing the
rest of the device.

So with this, we could now get rid of the 'bd_set_size()' block size
code entirely - resulting in faster IO for the common case - but that
would be a separate patch.
Reported-and-tested-by: NRomain Francoise <romain@orebokech.com>
Reporeted-and-tested-by: NMeelis Roos <mroos@linux.ee>
Reported-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Noticed by Pavel Roskin; the thing in his patch I disagree with
was compensating for that shite in callbacks instead of fixing
it once in the iterator itself.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We are leaking fattr and fhandle if we decide that dentry is not to
be invalidated, after all (e.g. happens to be a mountpoint).  Just
free both before that...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We really don't want to look at the block size for the raw block device
accesses in fs/block-dev.c, because it may be changing from under us.
So get rid of the max_block logic entirely, since the caller should
already have done it anyway.

That leaves the only user of this function in fs/buffer.c, so move the
whole function there and make it static.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since directio can work on a raw block device, and the block size of the
device can change under it, we need to do the same thing that
fs/buffer.c now does: read the block size a single time, using
ACCESS_ONCE().

Reading it multiple times can get different results, which will then
confuse the code because it actually encodes the i_blksize in
relationship to the underlying logical blocksize.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts the block-device direct access code to the previous
unlocked code, now that fs/buffer.c no longer needs external locking.

With this, fs/block_dev.c is back to the original version, apart from a
whitespace cleanup that I didn't want to revert.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This makes the buffer size handling be a per-page thing, which allows us
to not have to worry about locking too much when changing the buffer
size.  If a page doesn't have buffers, we still need to read the block
size from the inode, but we can do that with ACCESS_ONCE(), so that even
if the size is changing, we get a consistent value.

This doesn't convert all functions - many of the buffer functions are
used purely by filesystems, which in turn results in the buffer size
being fixed at mount-time.  So they don't have the same consistency
issues that the raw device access can have.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 6bdf6dbd caused a regression
in setattr codepath that leads to files with wrong attributes.
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>