f2fs: fix to unlock page before exit

If we got an error after lock_page, we should unlock it before exit.

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

f2fs: remove unnecessary kmap/kunmap operations

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.

f2fs: remove unnecessary kmap/kunmap operations

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>

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f2fs: add debug msgs in the recovery routine

This patch adds some trivial debugging messages in the recovery process.

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

f2fs: fix BUG_ON during f2fs_evict_inode(dir)

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

In the following scenario, a bug is captured.
1

f2fs: fix BUG_ON during f2fs_evict_inode(dir)

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>

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f2fs: fix por_doing variable coverage

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

f2fs: fix por_doing variable coverage

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>

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f2fs: remove redundant assignment

We don't need to assign a value redundantly.

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

f2fs: recover when journal contains deleted files

When recovering a journal file with fsync data for files that have
been deleted, don't bail out on recovery.

Signed-off-by: Chris Fries <C.Fries@mo

f2fs: recover when journal contains deleted files

When recovering a journal file with fsync data for files that have
been deleted, don't bail out on recovery.

Signed-off-by: Chris Fries <C.Fries@motorola.com>
Reviewed-by: Russell Knize <rknize2@motorola.com>
Reviewed-by: Jason Hrycay <jason.hrycay@motorola.com>
[Jaegeuk Kim: fit the coding style]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

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f2fs: introduce a new global lock scheme

In the previous version, f2fs uses global locks according to the usage types,
such as directory operations, block allocation, block write, and so on.

Refere

f2fs: introduce a new global lock scheme

In the previous version, f2fs uses global locks according to the usage types,
such as directory operations, block allocation, block write, and so on.

Reference the following lock types in f2fs.h.
enum lock_type {
RENAME, /* for renaming operations */
DENTRY_OPS, /* for directory operations */
DATA_WRITE, /* for data write */
DATA_NEW, /* for data allocation */
DATA_TRUNC, /* for data truncate */
NODE_NEW, /* for node allocation */
NODE_TRUNC, /* for node truncate */
NODE_WRITE, /* for node write */
NR_LOCK_TYPE,
};

In that case, we lose the performance under the multi-threading environment,
since every types of operations must be conducted one at a time.

In order to address the problem, let's share the locks globally with a mutex
array regardless of any types.
So, let users grab a mutex and perform their jobs in parallel as much as
possbile.

For this, I propose a new global lock scheme as follows.

0. Data structure
- f2fs_sb_info -> mutex_lock[NR_GLOBAL_LOCKS]
- f2fs_sb_info -> node_write

1. mutex_lock_op(sbi)
- try to get an avaiable lock from the array.
- returns the index of the gottern lock variable.

2. mutex_unlock_op(sbi, index of the lock)
- unlock the given index of the lock.

3. mutex_lock_all(sbi)
- grab all the locks in the array before the checkpoint.

4. mutex_unlock_all(sbi)
- release all the locks in the array after checkpoint.

5. block_operations()
- call mutex_lock_all()
- sync_dirty_dir_inodes()
- grab node_write
- sync_node_pages()

Note that,
the pairs of mutex_lock_op()/mutex_unlock_op() and
mutex_lock_all()/mutex_unlock_all() should be used together.

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

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f2fs: fix the recovery flow to handle errors correctly

We should handle errors during the recovery flow correctly.
For example, if we get -ENOMEM, we should report a mount failure instead of
conduct

f2fs: fix the recovery flow to handle errors correctly

We should handle errors during the recovery flow correctly.
For example, if we get -ENOMEM, we should report a mount failure instead of
conducting the remained mount procedure.

Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

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f2fs: reduce unncessary locking pages during read

This patch reduces redundant locking and unlocking pages during read operations.
In f2fs_readpage, let's use wait_on_page_locked() instead of lock_p

f2fs: reduce unncessary locking pages during read

This patch reduces redundant locking and unlocking pages during read operations.
In f2fs_readpage, let's use wait_on_page_locked() instead of lock_page.
And then, when we need to modify any data finally, let's lock the page so that
we can avoid lock contention.

[readpage rule]
- The f2fs_readpage returns unlocked page, or released page too in error cases.
- Its caller should handle read error, -EIO, after locking the page, which
indicates read completion.
- Its caller should check PageUptodate after grab_cache_page.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

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f2fs: introduce readahead mode of node pages

Previously, f2fs reads several node pages ahead when get_dnode_of_data is called
with RDONLY_NODE flag.
And, this flag is set by the following functions.

f2fs: introduce readahead mode of node pages

Previously, f2fs reads several node pages ahead when get_dnode_of_data is called
with RDONLY_NODE flag.
And, this flag is set by the following functions.
- get_data_block_ro
- get_lock_data_page
- do_write_data_page
- truncate_blocks
- truncate_hole

However, this readahead mechanism is initially introduced for the use of
get_data_block_ro to enhance the sequential read performance.

So, let's clarify all the cases with the additional modes as follows.

enum {
ALLOC_NODE, /* allocate a new node page if needed */
LOOKUP_NODE, /* look up a node without readahead */
LOOKUP_NODE_RA, /*
* look up a node with readahead called
* by get_datablock_ro.
*/
}

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>

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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()

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>

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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 r

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>

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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>

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. An

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>

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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.co

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>

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f2fs: remove unneeded INIT_LIST_HEAD at few places

While creating a new entry for addition to the list(orphan inode list
and fsync inode entry list), there is no need to call HEAD initialization
for

f2fs: remove unneeded INIT_LIST_HEAD at few places

While creating a new entry for addition to the list(orphan inode list
and fsync inode entry list), there is no need to call HEAD initialization
for these entries. So, remove that init part.

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>

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f2fs: fix fsync_inode list addition logic and avoid invalid access to memory

In function find_fsync_dnodes() - the fsync inodes gets added to the list, but
in one path suppose f2fs_iget results in e

f2fs: fix fsync_inode list addition logic and avoid invalid access to memory

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: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

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f2fs: handle error from f2fs_iget_nowait

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

f2fs: handle error from f2fs_iget_nowait

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: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

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f2fs: adjust kernel coding style

As pointed out by Randy Dunlap, this patch removes all usage of "/**" for comment
blocks. Instead, just use "/*".

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

f2fs: adjust kernel coding style

As pointed out by Randy Dunlap, this patch removes all usage of "/**" for comment
blocks. Instead, just use "/*".

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

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f2fs: fix endian conversion bugs reported by sparse

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

In m

f2fs: fix endian conversion bugs reported by sparse

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

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f2fs: add recovery routines for roll-forward

This adds roll-forward routines to recover fsynced data.

- F2FS uses basically roll-back model with checkpointing.

- In order to implement fsync(), the

f2fs: add recovery routines for roll-forward

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

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f2fs: fix to avoid racing on fsync_entry_slab by multi filesystem instances

commit cad83c968c2ebe97905f900326988ed37146c347 upstream.

As syzbot reported, there is an use-after-free

f2fs: fix to avoid racing on fsync_entry_slab by multi filesystem instances

commit cad83c968c2ebe97905f900326988ed37146c347 upstream.

As syzbot reported, there is an use-after-free issue during f2fs recovery:

Use-after-free write at 0xffff88823bc16040 (in kfence-#10):
kmem_cache_destroy+0x1f/0x120 mm/slab_common.c:486
f2fs_recover_fsync_data+0x75b0/0x8380 fs/f2fs/recovery.c:869
f2fs_fill_super+0x9393/0xa420 fs/f2fs/super.c:3945
mount_bdev+0x26c/0x3a0 fs/super.c:1367
legacy_get_tree+0xea/0x180 fs/fs_context.c:592
vfs_get_tree+0x86/0x270 fs/super.c:1497
do_new_mount fs/namespace.c:2905 [inline]
path_mount+0x196f/0x2be0 fs/namespace.c:3235
do_mount fs/namespace.c:3248 [inline]
__do_sys_mount fs/namespace.c:3456 [inline]
__se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433
do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae

The root cause is multi f2fs filesystem instances can race on accessing
global fsync_entry_slab pointer, result in use-after-free issue of slab
cache, fixes to init/destroy this slab cache only once during module
init/destroy procedure to avoid this issue.

Reported-by: syzbot+9d90dad32dd9727ed084@syzkaller.appspotmail.com
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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f2fs: fix error path in do_recover_data()

- don't panic kernel if f2fs_get_node_page() fails in
f2fs_recover_inline_data() or f2fs_recover_inline_xattr();
- return error number of f2

f2fs: fix error path in do_recover_data()

- don't panic kernel if f2fs_get_node_page() fails in
f2fs_recover_inline_data() or f2fs_recover_inline_xattr();
- return error number of f2fs_truncate_blocks() to
f2fs_recover_inline_data()'s caller;

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

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f2fs: split f2fs_allocate_new_segments()

to two independent functions:
- f2fs_allocate_new_segment() for specified type segment allocation
- f2fs_allocate_new_segments() for all data

f2fs: split f2fs_allocate_new_segments()

to two independent functions:
- f2fs_allocate_new_segment() for specified type segment allocation
- f2fs_allocate_new_segments() for all data type segments allocation

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

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