Introduce a new structure f2fs_journal to wrap journal info in struct
f2fs_summary_block for readability.

struct f2fs_journal {
	union {
		__le16 n_nats;
		__le16 n_sits;
	};
	union {
		struct nat_journal nat_j;
		struct sit_journal sit_j;
		struct f2fs_extra_info info;
	};
} __packed;

struct f2fs_summary_block {
	struct f2fs_summary entries[ENTRIES_IN_SUM];
	struct f2fs_journal journal;
	struct summary_footer footer;
} __packed;
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adopts f2fs with codes of ext4, it removes unneeded memory
allocation in creating/accessing path of symlink.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

f2fs support atomic write with following semantics:
1. open db file
2. ioctl start atomic write
3. (write db file) * n
4. ioctl commit atomic write
5. close db file

With this flow we can avoid file becoming corrupted when abnormal power
cut, because we hold data of transaction in referenced pages linked in
inmem_pages list of inode, but without setting them dirty, so these data
won't be persisted unless we commit them in step 4.

But we should still hold journal db file in memory by using volatile
write, because our semantics of 'atomic write support' is incomplete, in
step 4, we could fail to submit all dirty data of transaction, once
partial dirty data was committed in storage, then after a checkpoint &
abnormal power-cut, db file will be corrupted forever.

So this patch tries to improve atomic write flow by adding a revoking flow,
once inner error occurs in committing, this gives another chance to try to
revoke these partial submitted data of current transaction, it makes
committing operation more like aotmical one.

If we're not lucky, once revoking operation was failed, EAGAIN will be
reported to user for suggesting doing the recovery with held journal file,
or retrying current transaction again.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Split drop_inmem_pages from commit_inmem_pages for code readability,
and prepare for the following modification.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adopts:
	ext4 crypto: ext4_page_crypto() doesn't need a encryption context

Since ext4_page_crypto() doesn't need an encryption context (at least
not any more), this allows us to simplify a number function signature
and also allows us to avoid needing to allocate a context in
ext4_block_write_begin().  It also means we no longer need a separate
ext4_decrypt_one() function.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch preallocates data blocks for buffered aio writes.
With this patch, we can avoid redundant locking and unlocking of node pages
given consecutive aio request.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch moves preallocation code for direct IOs into f2fs_file_write_iter.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

f2fs use single bio buffer per type data (META/NODE/DATA) for caching
writes locating in continuous block address as many as possible, after
submitting, these writes may be still cached in bio buffer, so we have
to flush cached writes in bio buffer by calling f2fs_submit_merged_bio.

Unfortunately, in the scenario of high concurrency, bio buffer could be
flushed by someone else before we submit it as below reasons:
a) there is no space in bio buffer.
b) add a request of different type (SYNC, ASYNC).
c) add a discontinuous block address.

For this condition, f2fs_submit_merged_bio will be devastating, because
it could break the following merging of writes in bio buffer, split one
big bio into two smaller one.

This patch introduces f2fs_submit_merged_bio_cond which can do a
conditional submitting with bio buffer, before submitting it will judge
whether:
 - page in DATA type bio buffer is matching with specified page;
 - page in DATA type bio buffer is belong to specified inode;
 - page in NODE type bio buffer is belong to specified inode;
If there is no eligible page in bio buffer, we will skip submitting step,
result in gaining more chance to merge consecutive block IOs in bio cache.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch makes f2fs_map_blocks supporting returning next potential
page offset which skips hole region in indirect tree of inode, and
use it to speed up fiemap in handling big hole case.

Test method:
xfs_io -f /mnt/f2fs/file  -c "pwrite 1099511627776 4096"
time xfs_io -f /mnt/f2fs/file -c "fiemap -v"

Before:
time xfs_io -f /mnt/f2fs/file -c "fiemap -v"
/mnt/f2fs/file:
 EXT: FILE-OFFSET              BLOCK-RANGE      TOTAL FLAGS
   0: [0..2147483647]:         hole             2147483648
   1: [2147483648..2147483655]: 81920..81927         8   0x1

real    3m3.518s
user    0m0.000s
sys     3m3.456s

After:
time xfs_io -f /mnt/f2fs/file -c "fiemap -v"
/mnt/f2fs/file:
 EXT: FILE-OFFSET              BLOCK-RANGE      TOTAL FLAGS
   0: [0..2147483647]:         hole             2147483648
   1: [2147483648..2147483655]: 81920..81927         8   0x1

real    0m0.008s
user    0m0.000s
sys     0m0.008s
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

When seeking data in ->llseek, if we encounter a big hole which covers
several dnode pages, we will try to seek data from index of page which
is the first page of next dnode page, at most we could skip searching
(ADDRS_PER_BLOCK - 1) pages.

However it's still not efficient, because if our indirect/double-indirect
pointer are NULL, there are no dnode page locate in the tree indirect/
double-indirect pointer point to, it's not necessary to search the whole
region.

This patch introduces get_next_page_offset to calculate next page offset
based on current searching level and max searching level returned from
get_dnode_of_data, with this, we could skip searching the entire area
indirect or double-indirect node block is not exist.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

There are redundant pointer conversion in following call stack:
 - at position a, inode was been converted to f2fs_file_info.
 - at position b, f2fs_file_info was been converted to inode again.

 - truncate_blocks(inode,..)
  - fi = F2FS_I(inode)		---a
  - ADDRS_PER_PAGE(node_page, fi)
   - addrs_per_inode(fi)
    - inode = &fi->vfs_inode	---b
    - f2fs_has_inline_xattr(inode)
     - fi = F2FS_I(inode)
     - is_inode_flag_set(fi,..)

In order to avoid unneeded conversion, alter ADDRS_PER_PAGE and
addrs_per_inode to acept parameter with type of inode pointer.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch introduces lifetime IO write statistics exposed to the sysfs interface.
The write IO amount is obtained from block layer, accumulated in the file system and
stored in the hot node summary of checkpoint.
Signed-off-by: NShuoran Liu <liushuoran@huawei.com>
Signed-off-by: NPengyang Hou <houpengyang@huawei.com>
[Jaegeuk Kim: add sysfs documentation]
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

On the worst case, we need to scan the whole radix tree and every rb-tree to
free the victimed extent_nodes when shrinking.

Pengyang initially introduced a victim_list to record the victimed extent_nodes,
and free these extent_nodes by just scanning a list.

Later, Chao Yu enhances the original patch to improve memory footprint by
removing victim list.

The policy of lru list shrinking becomes:
1) lock lru list's lock
2) trylock extent tree's lock
3) remove extent node from lru list
4) unlock lru list's lock
5) do shrink
6) repeat 1) to 5)
Signed-off-by: NHou Pengyang <houpengyang@huawei.com>
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In write_begin, if storage supports stable_page, we don't need to wait for
writeback to update its contents.
This patch introduces to use wait_for_stable_page instead of
wait_on_page_writeback.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch exports a new sysfs entry 'dirty_nat_ratio' to control threshold
of dirty nat entries, if current ratio exceeds configured threshold,
checkpoint will be triggered in f2fs_balance_fs_bg for flushing dirty nats.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Operations in is_merged_page is related to inner bio cache, move it to
data.c.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds to show the number of background checkpoint.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds last time that user requested filesystem operations.
This information is used to detect whether system is idle or not later.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds time and interval arrays to store some timing variables.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

1. rename field in struct extent_tree from count to node_cnt for
   readability.
2. alter to use atomic type for node_cnt.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds one parameter to clean up all the callers of f2fs_balance_fs.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Only when node page is newly dirtied, it needs to check whether we need to do
f2fs_gc.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Introduce max_file_blocks in sbi to store max block index of file in f2fs,
it could be used to avoid unneeded calculation of max block index in
runtime.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: fix overflow of sbi->max_file_blocks]
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch removes refcount, and instead, adds zombie_list to shrink directly
without radix tree traverse.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds an entry to show the number of zombie extent_tree.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Otherwise, we can get mismatched largest extent information.

One example is:
1. mount f2fs w/ extent_cache
2. make a small extent
3. umount
4. mount f2fs w/o extent_cache
5. update the largest extent
6. umount
7. mount f2fs w/ extent_cache
8. get the old extent made by #2Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds a max block check for get_data_block_bmap.

Trinity test program will send a block number as parameter into
ioctl_fibmap, which will be used in get_node_path(), when the block
number large than f2fs max blocks, it will trigger kernel bug.
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Signed-off-by: NXue Liu <liuxueliu.liu@huawei.com>
[Jaegeuk Kim: fix missing condition, pointed by Chao Yu]
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Sometimes we keep dumb when IO error occur in lower layer device, so user
will not receive any error return value for some operation, but actually,
the operation did not succeed.

This sould be avoided, so this patch reports such kind of error to user.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

do_checkpoint and write_checkpoint can fail due to reasons like triggering
in a readonly fs or encountering IO error of storage device.

So it's better to report such error info to user, let user be aware of
failure of doing checkpoint.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch introduces recording node block allocation in dnode_of_data.
This information helps to figure out whether any node block is allocated during
specific file operations.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If there is no candidates for shrinking slab entries, we don't need to traverse
any trees at all.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: fix missing initialization reported by Yunlei He]
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

It would be better to use atomic variable for total_extent_tree.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Add to stat dirty regular and symlink inode for showing in debugfs.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Add a new option 'data_flush' to enable data flush functionality.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Maintain regular/symlink inode which has dirty pages in global dirty list
and record their total dirty pages count like the way of handling directory
inode.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We have already got one copy of valid super block in memory, do not grab
buffer header of super block all the time.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Add a new dirt list node member in inode info for linking the inode to
global dirty list in superblock, instead of old implementation which
allocate slab cache memory as an entry to inode.

It avoids memory pressure due to slab cache allocation, and also makes
codes more clean.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

remove_dirty_dir_inode will be renamed to remove_dirty_inode as a generic
function in following patch for removing directory/regular/symlink inode
in global dirty list.

Here rename ino management related functions for readability, also in
order to avoid name conflict.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

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

Use sbi->blocks_per_seg directly to avoid unnecessary calculation when using
1 << sbi->log_blocks_per_seg.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>