Commit Graph

106 Commits

Author SHA1 Message Date
Eric W. Biederman 7f78e03513 fs: Limit sys_mount to only request filesystem modules.
Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.

A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.

Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.

Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives.  Allowing simple, safe,
well understood work-arounds to known problematic software.

This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work.  While writing this patch I saw a handful of such
cases.  The most significant being autofs that lives in the module
autofs4.

This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.

After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module.  The common pattern in the kernel is to call request_module()
without regards to the users permissions.  In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted.  In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-03 19:36:31 -08:00
Al Viro 6131ffaa1f more file_inode() open-coded instances
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-27 16:59:05 -05:00
Linus Torvalds d895cb1af1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile (part one) from Al Viro:
 "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
  locking violations, etc.

  The most visible changes here are death of FS_REVAL_DOT (replaced with
  "has ->d_weak_revalidate()") and a new helper getting from struct file
  to inode.  Some bits of preparation to xattr method interface changes.

  Misc patches by various people sent this cycle *and* ocfs2 fixes from
  several cycles ago that should've been upstream right then.

  PS: the next vfs pile will be xattr stuff."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
  saner proc_get_inode() calling conventions
  proc: avoid extra pde_put() in proc_fill_super()
  fs: change return values from -EACCES to -EPERM
  fs/exec.c: make bprm_mm_init() static
  ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
  ocfs2: fix possible use-after-free with AIO
  ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
  get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
  target: writev() on single-element vector is pointless
  export kernel_write(), convert open-coded instances
  fs: encode_fh: return FILEID_INVALID if invalid fid_type
  kill f_vfsmnt
  vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
  nfsd: handle vfs_getattr errors in acl protocol
  switch vfs_getattr() to struct path
  default SET_PERSONALITY() in linux/elf.h
  ceph: prepopulate inodes only when request is aborted
  d_hash_and_lookup(): export, switch open-coded instances
  9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
  9p: split dropping the acls from v9fs_set_create_acl()
  ...
2013-02-26 20:16:07 -08:00
Al Viro 496ad9aa8e new helper: file_inode(file)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22 23:31:31 -05:00
Jaegeuk Kim 7dd690c820 f2fs: avoid build warning
This patch removes the following build warning:
fs/f2fs/node.c: warning: 'nofs' may be used uninitialized in this function
[-Wuninitialized]:  => 738:8

Note that this is a false alarm.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:28:55 +09:00
Jaegeuk Kim 90b2fc64f0 Merge branch 'f2fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs into dev
Pull f2fs cleanup patches from Al Viro:

f2fs: get rid of fake on-stack dentries
f2fs: switch init_inode_metadata() to passing parent and name separately
f2fs: switch new_inode_page() from dentry to qstr
f2fs: init_dent_inode() should take qstr

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

Conflicts:
	fs/f2fs/recovery.c
2013-02-12 07:17:20 +09:00
Namjae Jeon e975082411 f2fs: add compat_ioctl to provide backward compatability
adding compat_ioctl to provide support for backward comptability - 32bit binary
execution on 64bit kernel.

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>
2013-02-12 07:15:02 +09:00
Jaegeuk Kim b7250d2d84 f2fs: fix calculation of max. gc cost in the SSR case
In the SSR case, the max gc cost should be the number of pages in a segment.
Otherwise, f2fs is able to fail getting dirty segments frequently for SSR.

In get_victim_by_default() previously,

while(1) {
   ...
   cost = get_gc_cost(); <- cost is between 0 ~ 512.
   ...
   if (cost == get_max_cost(sbi, &p)) <- max cost is UINT_MAX due to GC_CB type
	continue;

   if (nsearched++ >= MAX_VICTIM_SEARCH)
	break;
}

So, if there are a number of fully valid segments in series, f2fs cannot skip
those segments by comparing the cost and max cost of each segment.

Note that, the cost is the number of valid blocks at the time of the last
checkpoint.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:15:02 +09:00
Jaegeuk Kim 437275272f f2fs: clarify and enhance the f2fs_gc flow
This patch makes clearer the ambiguous f2fs_gc flow as follows.

1. Remove intermediate checkpoint condition during f2fs_gc
 (i.e., should_do_checkpoint() and GC_BLOCKED)

2. Remove unnecessary return values of f2fs_gc because of #1.
 (i.e., GC_NODE, GC_OK, etc)

3. Simplify write_checkpoint() because of #2.

4. Clarify the main f2fs_gc flow.
 o monitor how many freed sections during one iteration of do_garbage_collect().
 o do GC more without checkpoints if we can't get enough free sections.
 o do checkpoint once we've got enough free sections through forground GCs.

5. Adopt thread-logging (Slack-Space-Recycle) scheme more aggressively on data
  log types. See. get_ssr_segement()

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:15:02 +09:00
Namjae Jeon b1f1daf8c7 f2fs: optimize the return condition for has_not_enough_free_secs
Instead of evaluating the free_sections and then deciding to return
true/false from that path. We can directly use the evaluation condition
for returning proper value.

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>
2013-02-12 07:15:02 +09:00
Namjae Jeon 5ac206cf4f f2fs: make an accessor to get sections for particular block type
Introduce accessor to get the sections based upon the block type
(node,dents...) and modify the functions : should_do_checkpoint,
has_not_enough_free_secs to use this accessor function to get
the node sections and dent sections.

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>
2013-02-12 07:15:02 +09:00
Namjae Jeon 25718423ea f2fs: mark gc_thread as NULL when thread creation is failed
When gc thread creation is failed, mark gc_thread as NULL to avoid
crash while trying to stop invalid thread in stop_gc_thread->kthread_stop.
Instead make it return from:
	if (!gc_th)
       return;

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>
2013-02-12 07:15:02 +09:00
Namjae Jeon ec7b1f2dd1 f2fs: name gc task as per the block device
Currently GC task is started for each f2fs formatted/mounted device.
But, when we check the task list, using 'ps', there is no distinguishing
factor between the tasks. So, name the task as per the block device just
like the flusher threads.
Also, remove the macro GC_THREAD_NAME and instead use the name: f2fs_gc
to avoid name length truncation, as the command length is 16
-> TASK_COMM_LEN 16 and example name like:
f2fs_gc_task:8:16 -> this exceeds name length

Before Patch for 2 F2FS formatted partitions:
root  28061  0.0  0.0  0 0 ? S 10:31   0:00 [f2fs_gc_task]
root  28087  0.0  0.0  0 0 ? S 10:32   0:00 [f2fs_gc_task]

After Patch:
root  16756  0.0  0.0  0  0 ?  S  14:57   0:00 [f2fs_gc-8:18]
root  16765  0.0  0.0  0  0 ?  S  14:57   0:00 [f2fs_gc-8:19]

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>
2013-02-12 07:15:02 +09:00
Changman Lee 48600e44c1 f2fs: remove unnecessary gc option check and balance_fs
1. If f2fs is mounted with background_gc_off option, checking
    BG_GC is not redundant.
 2. f2fs_balance_fs is checked in f2fs_gc, so this is also redundant.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
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>
2013-02-12 07:15:02 +09:00
Changman Lee 94787d91cb f2fs: remove repeated F2FS_SET_SB_DIRT call
F2FS_SET_SB_DIRT is called in inc_page_count and
it is directly called one more time in the next line.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:15:01 +09:00
majianpeng 14d7e9de05 f2fs: when check superblock failed, try to check another superblock
In f2fs, there are two superblocks. So when the first superblock was
invalidate, it should try to check another.

By Jaegeuk Kim:
 o Remove a white space for coding style
 o Clean up for code readability
 o Fix a typo

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:15:01 +09:00
majianpeng 5c9b469295 f2fs: use F2FS_BLKSIZE to judge bloksize and page_cache_size
In some system PAGE_CACHE_SIZE isn't 4K. So using F2FS_BLKSIZE to judge.

By Jaegeuk Kim:
 o f2fs does not support no other 4KB page cache size.

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:15:01 +09:00
majianpeng f83759e283 f2fs: add device name in debugfs
In file status, it can't distinguish between different devices.
So add device name to do this function.

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:15:01 +09:00
Changman Lee facb020540 f2fs: stop repeated checking if cp is needed
If it is decided that f2fs should do checkpoint, skip next comparison.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
2013-02-12 07:15:01 +09:00
Jaegeuk Kim d4686d56ec f2fs: avoid balanc_fs during evict_inode
1. Background

Previously, if f2fs tries to move data blocks of an *evicting* inode during the
cleaning process, it stops the process incompletely and then restarts the whole
process, since it needs a locked inode to grab victim data pages in its address
space. In order to get a locked inode, iget_locked() by f2fs_iget() is normally
used, but, it waits if the inode is on freeing.

So, here is a deadlock scenario.
1. f2fs_evict_inode()       <- inode "A"
  2. f2fs_balance_fs()
    3. f2fs_gc()
      4. gc_data_segment()
        5. f2fs_iget()      <- inode "A" too!

If step #1 and #5 treat a same inode "A", step #5 would fall into deadlock since
the inode "A" is on freeing. In order to resolve this, f2fs_iget_nowait() which
skips __wait_on_freeing_inode() was introduced in step #5, and stops f2fs_gc()
to complete f2fs_evict_inode().

1. f2fs_evict_inode()           <- inode "A"
  2. f2fs_balance_fs()
    3. f2fs_gc()
      4. gc_data_segment()
        5. f2fs_iget_nowait()   <- inode "A", then stop f2fs_gc() w/ -ENOENT

2. Problem and Solution

In the above scenario, however, f2fs cannot finish f2fs_evict_inode() only if:
 o there are not enough free sections, and
 o f2fs_gc() tries to move data blocks of the *evicting* inode repeatedly.

So, the final solution is to use f2fs_iget() and remove f2fs_balance_fs() in
f2fs_evict_inode().
The f2fs_evict_inode() actually truncates all the data and node blocks, which
means that it doesn't produce any dirty node pages accordingly.
So, we don't need to do f2fs_balance_fs() in practical.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:15:01 +09:00
Jaegeuk Kim 369a708c2a f2fs: remove the use of page_cache_release
Let's remove the use of page_cache_release() in f2fs, and instead, use
f2fs_put_page(page, 0) which is exactly same but for code readability.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:15:01 +09:00
Namjae Jeon 324ddc702e f2fs: fix typo mistake for data_version description
In f2fs_inode_info structure, the description for data_version
has a typo mistake. It should be latest instead of lastes.
So, correcting that.

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>
2013-02-12 07:15:01 +09:00
Namjae Jeon a2b52a598a f2fs: reorganize code for ra_node_page
We can remove unneeded label unlock_out, avoid unnecessary jump
and reorganize the returning conditions in this function.

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>
2013-02-12 07:15:01 +09:00
Namjae Jeon 3786dfdf4f f2fs: avoid redundant call to has_not_enough_free_secs in f2fs_gc
After doing a write_checkpoint from garbage collection path if there is still
need to do more garbage collection, gc_more label is used to jump and start
the process again. And in that process, first step before getting victim is to
check if there are not enough free sections, which is already done before
doing a jump to gc_more. We can avoid the redundant call to check free
sections, by checking the gc_type flag which will remain FG_GC(value 1) under
this condition.

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>
2013-02-12 07:15:00 +09:00
Changman Lee d6212a5f18 f2fs: add un/freeze_fs into super_operations
This patch supports ioctl FIFREEZE and FITHAW to snapshot filesystem.
Before calling f2fs_freeze, all writers would be suspended and sync_fs
would be completed. So no f2fs has to do something.
Just background gc operation should be skipped due to generate dirty
nodes and data until unfreeze.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:15:00 +09:00
majianpeng a2617dc686 f2fs: clean up the add_orphan_inode func
For the code
> prev = list_entry(orphan->list.prev, typeof(*prev), list);
if orphan->list.prev == head, it can't get the right prev.
And we can use the parameter 'this' to add.

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:15:00 +09:00
Alejandro Martinez Ruiz aa43507f68 f2fs: fix disable_ext_identify option spelling
There is a typo in the ->show_options function for disable_ext_identify.
Fix it to match the spelling from the documentation.

Signed-off-by: Alejandro Martinez Ruiz <alex@nowcomputing.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:15:00 +09:00
Jaegeuk Kim bd43df021a f2fs: cover global locks for reserve_new_block
The fill_zero() from fallocate() calls get_new_data_page() in which calls
reserve_new_block().
The reserve_new_block() should be covered by *DATA_NEW*, one of global locks.
And also, before getting the lock, we should check free sections by calling
f2fs_balance_fs().

If we break this rule, f2fs is able to face with out-of-control free space
management and fall into infinite loop like the following scenario as well.

[f2fs_sync_fs()]             [fallocate()]
 - write_checkpoint()        - fill_zero()
  - block_operations()        - get_new_data_page()
   : grab NODE_NEW             - get_dnode_of_data()
                                : get locked dirty node page
    - sync_node_pages()
                                : try to grab NODE_NEW for data allocation
     : trylock and skip the dirty node page
   : call sync_node_pages() repeatedly in order to flush all the dirty node
     pages!

In order to avoid this, we should grab another global lock such as DATA_NEW
before calling get_new_data_page() in fill_zero().

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:15:00 +09:00
Jaegeuk Kim 577e349514 f2fs: prevent checkpoint once any IO failure is detected
This patch enhances the checkpoint routine to cope with IO errors.

Basically f2fs detects IO errors from end_io_write, and the errors are able to
be occurred during one of data, node, and meta page writes.

In the previous code, when an IO error is occurred during writes, f2fs sets a
flag, CP_ERROR_FLAG, in the raw ckeckpoint buffer which will be written to disk.
Afterwards, write_checkpoint() will check the flag and remount f2fs as a
read-only (ro) mode.

However, even once f2fs is remounted as a ro mode, dirty checkpoint pages are
freely able to be written to disk by flusher or kswapd in background.
In such a case, after cold reboot, f2fs would restore the checkpoint data having
CP_ERROR_FLAG, resulting in disabling write_checkpoint and remounting f2fs as
a ro mode again.

Therefore, let's prevent any checkpoint page (meta) writes once an IO error is
occurred, and remount f2fs as a ro mode right away at that moment.

Reported-by: Oliver Winker <oliver@oli1170.net>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
2013-02-12 07:15:00 +09:00
Changman Lee 7d79e75f64 f2fs: save device node number into f2fs_inode
This patch stores inode->i_rdev into on-disk inode structure.

Alun reported that:
 aspire tmp # mount -t f2fs /dev/sdb mnt
 aspire tmp # mknod mnt/sda1 b 8 1
 aspire tmp # mknod mnt/null c 1 3
 aspire tmp # mknod mnt/console c 5 1
 aspire tmp # ls -l mnt
 total 2
 crw-r--r-- 1 root root 5, 1 Jan 22 18:44 console
 crw-r--r-- 1 root root 1, 3 Jan 22 18:44 null
 brw-r--r-- 1 root root 8, 1 Jan 22 18:44 sda1
 aspire tmp # umount mnt
 aspire tmp # mount -t f2fs /dev/sdb mnt
 aspire tmp # ls -l mnt
 total 2
 crw-r--r-- 1 root root 0, 0 Jan 22 18:44 console
 crw-r--r-- 1 root root 0, 0 Jan 22 18:44 null
 brw-r--r-- 1 root root 0, 0 Jan 22 18:44 sda1

In this report, f2fs lost the major/minor numbers of device files after umount.
The reason was revealed that f2fs does not store the inode->i_rdev to the
on-disk inode data structure.

So, as the other file systems do, f2fs also stores i_rdev into the i_addr fields
in on-disk inode structure without any on-disk layout changes.
Note that, this bug is limited to device files made by mknod().

Reported-and-Tested-by: Alun Jones <alun.linux@ty-penguin.org.uk>
Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:15:00 +09:00
Al Viro b7f7a5e0be f2fs: get rid of fake on-stack dentries
those should never be used for a lot of reasons...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-08 02:55:04 -05:00
Al Viro 69f24eac55 f2fs: switch init_inode_metadata() to passing parent and name separately
... sure, it's tempting to just pass dentry.  Except that we don't
_have_ anything resembling a real dentry on one of the paths to it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-08 02:55:04 -05:00
Al Viro c004363dd6 f2fs: switch new_inode_page() from dentry to qstr
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-08 02:55:03 -05:00
Al Viro 53dc9a6776 f2fs: init_dent_inode() should take qstr
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: Al Viro <viro@zeniv.linux.org.uk>
2013-02-08 02:55:03 -05:00
Dan Carpenter d8b79b2f94 f2fs: use _safe() version of list_for_each
This is calling list_del() inside a loop which is a problem when we try
move to the next item on the list.  I've converted it to use the _safe
version.  And also, as a cleanup, I've converted it to use
list_for_each_entry instead of list_for_each.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-22 10:49:00 +09:00
Jaegeuk Kim 9af45ef5ab f2fs: add comments of start_bidx_of_node
The caller of start_bidx_of_node() should give proper node offsets which
point only direct node blocks. Otherwise, it is a caller's bug.
This patch adds comments to make it clear.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-22 10:48:59 +09:00
Jaegeuk Kim a7fdffbd3e f2fs: avoid issuing small bios due to several dirty node pages
If some small bios of dirty node pages are supposed to be issued during the
sequential data writes, there-in well-produced consecutive data bios are able
to be split by the small node bios, resulting in performance degradation.
So, let's collect a number of dirty node pages until reaching a threshold.
And, by default, I set the threshold as 2MB, a segment size.

This improves sequential write performance on i5, 512GB SSD (830 w/ SATA2) as
follows.
Before: 231 MB/s -> After: 255 MB/s

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
2013-01-22 10:48:59 +09:00
Jaegeuk Kim c01e54b770 f2fs: support swapfile
This patch adds f2fs_bmap operation to the data address space.
This enables f2fs to support swapfile.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-22 10:48:58 +09:00
Jaegeuk Kim 692bb55d1a f2fs: add remap_pages as generic_file_remap_pages
This was added for all the file systems before.

See the following commit.

commit id: 0b173bc4da

[PATCH] mm: kill vma flag VM_CAN_NONLINEAR

This patch moves actual ptes filling for non-linear file mappings
into special vma operation: ->remap_pages().

File system must implement this method to get non-linear mappings support,
if it uses filemap_fault() then generic_file_remap_pages() can be used.

Now device drivers can implement this method and obtain nonlinear vma support."

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-22 10:48:58 +09:00
Namjae Jeon 6e6093a8f1 f2fs: add __init to functions in init_f2fs_fs
Add __init to functions in init_f2fs_fs for code consistency.

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>
2013-01-22 10:48:38 +09:00
Namjae Jeon 4589d25d01 f2fs: fix the debugfs entry creation path
As the "status" debugfs entry will be maintained for entire F2FS filesystem
irrespective of the number of partitions.
So, we can move the initialization to the init part of the f2fs and destroy will
be done from exit part. After making changes, for individual partition mount -
entry creation code will not be executed.

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
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>
2013-01-15 20:19:15 +09:00
majianpeng 66af62ce75 f2fs: add global mutex_lock to protect f2fs_stat_list
There is an race condition between umounting f2fs and reading f2fs/status, which
results in oops.

Fox example:
Thread A			Thread B
umount f2fs 			cat f2fs/status

f2fs_destroy_stats() {		stat_show() {
				 list_for_each_entry_safe(&f2fs_stat_list)
 list_del(&si->stat_list);
 mutex_lock(&si->stat_lock);
 si->sbi = NULL;
 mutex_unlock(&si->stat_lock);
 kfree(sbi->stat_info);
} 				 mutex_lock(&si->stat_lock) <- si is gone.
				 ...
				}

Solution with a global lock: f2fs_stat_mutex:
Thread A			Thread B
umount f2fs 			cat f2fs/status

f2fs_destroy_stats() {		stat_show() {
 mutex_lock(&f2fs_stat_mutex);
 list_del(&si->stat_list);
 mutex_unlock(&f2fs_stat_mutex);
 kfree(sbi->stat_info);		 mutex_lock(&f2fs_stat_mutex);
}				 list_for_each_entry_safe(&f2fs_stat_list)
				 ...
				 mutex_unlock(&f2fs_stat_mutex);
				}

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
[jaegeuk.kim@samsung.com: fix typos, description, and remove the existing lock]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-15 20:18:29 +09:00
Namjae Jeon fa9150a84c f2fs: remove the blk_plug usage in f2fs_write_data_pages
Let's consider the usage of blk_plug in f2fs_write_data_pages().
We can come up with the two issues: lock contention and task awareness.

1. Merging bios prior to grabing "queue lock"
 The f2fs merges consecutive IOs in the file system level before
 submitting any bios, which is similar with the back merge by the
 plugging mechanism in attempt_plug_merge(). Both of them need to acquire
 no queue lock.

2. Merging policy with respect to tasks
 The f2fs merges IOs as much as possible regardless of tasks, while
 blk-plugging is conducted on a basis of tasks. As we can understand
 there are trade-offs, f2fs tries to maximize the write performance with
 well-merged bios.

As a result, if f2fs produces many consecutive but separated bios in
writepages(), it would be good to use blk-plugging since f2fs would be
able to avoid queue lock contention in the block layer by merging them.
But, f2fs merges IOs and submit one bio, which means that there are not
much chances to merge bios by attempt_plug_merge().

However, f2fs has already been used blk_plug by triggering generic_writepages()
in f2fs_write_data_pages().
So to make the overall code consistency, I'd like to remove blk_plug there.

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>
2013-01-15 20:18:16 +09:00
Namjae Jeon 163799872b f2fs: avoid redundant time update for parent directory in f2fs_delete_entry
In call to f2fs_delete_entry, 'dir' time modification code is put
at two places.
So, remove the redundant code for timing update.

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>
2013-01-14 09:43:27 +09:00
Namjae Jeon ff9234ad4e f2fs: remove redundant call to set_blocksize in f2fs_fill_super
Since, f2fs supports only 4KB blocksize, which is set at the beginning in
f2fs_fill_super. So, we do not need to again check this blocksize setting
in such case.

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>
2013-01-14 09:41:30 +09:00
Jaegeuk Kim 9eaeba7013 f2fs: move f2fs_balance_fs to punch_hole
The f2fs_fallocate() has two operations: punch_hole and expand_size.

Only in the case of punch_hole, dirty node pages can be produced, so let's
trigger f2fs_balance_fs() in this case only.
Furthermore, let's trigger it at every data truncation routine.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-11 15:09:23 +09:00
Jaegeuk Kim 7d82db8316 f2fs: add f2fs_balance_fs in several interfaces
The f2fs_balance_fs() is to check the number of free sections and decide whether
it needs to conduct cleaning or not. If there are not enough free sections, the
cleaning job should be started.

In order to control an amount of free sections even under high utilization, f2fs
should call f2fs_balance_fs at all the VFS interfaces that are able to produce
dirty pages.
This patch adds the function calls in the missing interfaces as follows.

1. f2fs_setxattr()
The f2fs_setxattr() produces dirty node pages so that we should call
f2fs_balance_fs() either likewise doing in other VFS interfaces such as
f2fs_lookup(), f2fs_mkdir(), and so on.

2. f2fs_sync_file()
We should guarantee serving free sections for syncing metadata during fsync.
Previously, there is no space check before triggering checkpoint and
sync_node_pages.
Therefore, if a bunch of fsync calls are triggered under 100% of FS utilization,
f2fs is able to be faced with no free sections, resulting in BUG_ON().

3. f2fs_sync_fs()
Before calling write_checkpoint(), we should guarantee that there are minimum
free sections.

4. f2fs_write_inode()
f2fs_write_inode() is also able to produce dirty node pages.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-11 15:09:17 +09:00
Jaegeuk Kim 408e937561 f2fs: revisit the f2fs_gc flow
I'd like to revisit the f2fs_gc flow and rewrite as follows.

1. In practical, the nGC parameter of f2fs_gc is meaningless. So, let's
  remove it.
2. Background GC marks victim blocks as dirty one at a time.
3. Foreground GC should do cleaning job until acquiring enough free
  sections. Afterwards, it needs to do checkpoint.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-10 07:42:59 +09:00
Jaegeuk Kim c335a86930 f2fs: check return value during recovery
This patch resolves Coverity #753102:

>>> No check of the return value of "f2fs_add_link(&dent, inode)".

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-04 09:46:27 +09:00
Jaegeuk Kim c1b75eabec f2fs: avoid null dereference in f2fs_acl_from_disk
This patch resolves Coverity #751303:

>>> CID 753103: Explicit null dereferenced (FORWARD_NULL) Passing null
>>> pointer "value" to function "f2fs_acl_from_disk(char const *, size_t)",
	which dereferences it.

[Error path]
- value = NULL;
- retval = 0 by f2fs_getxattr();
- f2fs_acl_from_disk(value:NULL, ...);

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-04 09:46:27 +09:00