Correct spelling typo in comments
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Acked-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

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

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

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: NJaegeuk Kim <jaegeuk.kim@samsung.com>

adding compat_ioctl to provide support for backward comptability - 32bit binary
execution on 64bit kernel.
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 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: NJaegeuk Kim <jaegeuk.kim@samsung.com>

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: NJaegeuk Kim <jaegeuk.kim@samsung.com>

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: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

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: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

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: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

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: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

 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: NChangman Lee <cm224.lee@samsung.com>
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>

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: NChangman Lee <cm224.lee@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

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: NJianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

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: NJianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

In file status, it can't distinguish between different devices.
So add device name to do this function.
Signed-off-by: NJianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

If it is decided that f2fs should do checkpoint, skip next comparison.
Signed-off-by: NChangman Lee <cm224.lee@samsung.com>

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: NJaegeuk Kim <jaegeuk.kim@samsung.com>

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: NJaegeuk Kim <jaegeuk.kim@samsung.com>

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: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

We can remove unneeded label unlock_out, avoid unnecessary jump
and reorganize the returning conditions in this function.
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>

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: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAmit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

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: NChangman Lee <cm224.lee@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

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: NJianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

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: NAlejandro Martinez Ruiz <alex@nowcomputing.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

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: NJaegeuk Kim <jaegeuk.kim@samsung.com>

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: NOliver Winker <oliver@oli1170.net>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>
Reviewed-by: NNamjae Jeon <namjae.jeon@samsung.com>

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: NAlun Jones <alun.linux@ty-penguin.org.uk>
Signed-off-by: NChangman Lee <cm224.lee@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

those should never be used for a lot of reasons...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... 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: NAl Viro <viro@zeniv.linux.org.uk>

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

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 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: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

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: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

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: NJaegeuk Kim <jaegeuk.kim@samsung.com>
Reviewed-by: NNamjae Jeon <namjae.jeon@samsung.com>

This patch adds f2fs_bmap operation to the data address space.
This enables f2fs to support swapfile.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This was added for all the file systems before.

See the following commit.

commit id: 0b173bc4

[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: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Add __init to functions in init_f2fs_fs for code consistency.
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>

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: NJianpeng Ma <majianpeng@gmail.com>
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>

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: NJianpeng Ma <majianpeng@gmail.com>
[jaegeuk.kim@samsung.com: fix typos, description, and remove the existing lock]
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>