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239 Commits (0c872e2dedfc09f41a5604d1c5010f800c0bd8f1)

Author SHA1 Message Date
Chao Yu 0c872e2ded f2fs: move ext_lock out of struct extent_info
Move ext_lock out of struct extent_info, then in the following patches we can
use variables with struct extent_info type as a parameter to pass pure data.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-03-03 09:58:45 -08:00
Chao Yu 3b4d732a56 f2fs: introduce f2fs_update_dentry to clean up duplicated codes
This patch introduces f2fs_update_dentry to remove redundant code in
f2fs_add_inline_entry and __f2fs_add_link.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-03-03 09:58:44 -08:00
Chao Yu 1753396a0a f2fs: remove unused inline_dentry_addr
inline_dentry_addr is introduced with inline dentry feature without being used,
now we do not need to keep it for any reason, so remove it.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-03-03 09:58:44 -08:00
Jaegeuk Kim 29e7043f40 f2fs: fix sparse warnings
This patch resolves the following warnings.

include/trace/events/f2fs.h:150:1: warning: expression using sizeof bool
include/trace/events/f2fs.h:180:1: warning: expression using sizeof bool
include/trace/events/f2fs.h:990:1: warning: expression using sizeof bool
include/trace/events/f2fs.h:990:1: warning: expression using sizeof bool
include/trace/events/f2fs.h:150:1: warning: odd constant _Bool cast (ffffffffffffffff becomes 1)
include/trace/events/f2fs.h:180:1: warning: odd constant _Bool cast (ffffffffffffffff becomes 1)
include/trace/events/f2fs.h:990:1: warning: odd constant _Bool cast (ffffffffffffffff becomes 1)
include/trace/events/f2fs.h:990:1: warning: odd constant _Bool cast (ffffffffffffffff becomes 1)

fs/f2fs/checkpoint.c:27:19: warning: symbol 'inode_entry_slab' was not declared. Should it be static?
fs/f2fs/checkpoint.c:577:15: warning: cast to restricted __le32
fs/f2fs/checkpoint.c:592:15: warning: cast to restricted __le32

fs/f2fs/trace.c:19:1: warning: symbol 'pids' was not declared. Should it be static?
fs/f2fs/trace.c:21:21: warning: symbol 'last_io' was not declared. Should it be static?

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-02-11 17:04:49 -08:00
Jaegeuk Kim bba681cbb2 f2fs: introduce a batched trim
This patch introduces a batched trimming feature, which submits split discard
commands.

This is to avoid long latency due to huge trim commands.
If fstrim was triggered ranging from 0 to the end of device, we should lock
all the checkpoint-related mutexes, resulting in very long latency.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-02-11 17:04:44 -08:00
Chao Yu 487261f39b f2fs: merge {invalidate,release}page for meta/node/data pages
This patch merges ->{invalidate,release}page function for meta/node/data pages.

After this, duplication of codes could be removed.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-02-11 17:04:44 -08:00
Jaegeuk Kim d24bdcbfc6 f2fs: show the number of writeback pages in stat
This patch adds the # of writeback pages in stat info.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-02-11 17:04:43 -08:00
Jaegeuk Kim 119ee91445 f2fs: split UMOUNT and FASTBOOT flags
This patch adds FASTBOOT flag into checkpoint as follows.

 - CP_UMOUNT_FLAG is set when system is umounted.
 - CP_FASTBOOT_FLAG is set when intermediate checkpoint having node summaries
   was done.

So, if you get CP_UMOUNT_FLAG from checkpoint, the system was umounted cleanly.
Instead, if there was sudden-power-off, you can get CP_FASTBOOT_FLAG or nothing.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-02-11 17:04:41 -08:00
Chao Yu caf0047e7e f2fs: merge flags in struct f2fs_sb_info
Currently, there are several variables with Boolean type as below:

struct f2fs_sb_info {
...
	int s_dirty;
	bool need_fsck;
	bool s_closing;
...
	bool por_doing;
...
}

For this there are some issues:
1. there are some space of f2fs_sb_info is wasted due to aligning after Boolean
   type variables by compiler.
2. if we continuously add new flag into f2fs_sb_info, structure will be messed
   up.

So in this patch, we try to:
1. switch s_dirty to Boolean type variable since it has two status 0/1.
2. merge s_dirty/need_fsck/s_closing/por_doing variables into s_flag.
3. introduce an enum type which can indicate different states of sbi.
4. use new introduced universal interfaces is_sbi_flag_set/{set,clear}_sbi_flag
   to operate flags for sbi.

After that, above issues will be fixed.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-02-11 17:04:38 -08:00
Chao Yu feeb0debfb f2fs: make truncate_inline_date static
1. make truncate_inline_date static;
2. remove parameter @from of truncate_inline_date as callers only pass zero.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-02-11 17:04:37 -08:00
Chao Yu d49f3e8902 f2fs: add F2FS_IOC_GETVERSION support
In this patch we add the FS_IOC_GETVERSION ioctl for getting i_generation from
inode, after that, users can list file's generation number by using "lsattr -v".

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-02-11 17:04:35 -08:00
Jaegeuk Kim 30a5537f9a f2fs: trigger correct checkpoint during umount
This patch fixes to trigger checkpoint with umount flag when kill_sb was called.
In kill_sb, f2fs_sync_fs was finally called, but at this time, f2fs can't do
checkpoint with CP_UMOUNT.
After then, f2fs_put_super is not doing checkpoint, since it is not dirty.

So, this patch adds a flag to indicate f2fs_sync_fs is called during umount.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-02-11 17:04:32 -08:00
Jaegeuk Kim 6f0aacbc3c f2fs: update memory footprint information
This patch adds missing memory usages, and splits them in detail.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-02-11 17:04:31 -08:00
Jaegeuk Kim dd4e4b59b1 f2fs: add nat/sit entries into status
This patch adds NAT/SIT entry informations.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-01-09 17:02:28 -08:00
Jaegeuk Kim 38aa0889b2 f2fs: align direct_io'ed data to section
This patch aligns the start block address of a file for direct io to the f2fs's
section size.

Some flash devices manage an over 4KB-sized page as a write unit, and if the
direct_io'ed data are written but not aligned to that unit, the performance can
be degraded due to the partial page copies.

Thus, since f2fs has a section that is well aligned to FTL units, we can align
the block address to the section size so that f2fs avoids this misalignment.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-01-09 17:02:27 -08:00
Jaegeuk Kim e1509cf294 f2fs: clean up to remove parameter
This patch uses dn->data_blkaddr as a parameter for the destination block
address.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-01-09 17:02:26 -08:00
Chao Yu 062920734c f2fs: reuse inode_entry_slab in gc procedure for using slab more effectively
There are two slab cache inode_entry_slab and winode_slab using the same
structure as below:

struct dir_inode_entry {
	struct list_head list;	/* list head */
	struct inode *inode;	/* vfs inode pointer */
};

struct inode_entry {
	struct list_head list;
	struct inode *inode;
};

It's a little waste that the two cache can not share their memory space for each
other.
So in this patch we remove one redundant winode_slab slab cache, then use more
universal name struct inode_entry as remaining data structure name of slab,
finally we reuse the inode_entry_slab to store dirty dir item and gc item for
more effective.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-01-09 17:02:26 -08:00
Changman Lee b9a2c25207 f2fs: add block count by in-place-update in stat info
This patch adds block count by in-place-update in stat.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-01-09 17:02:25 -08:00
Jaegeuk Kim cf04e8eb55 f2fs: use f2fs_io_info to clean up messy parameters during IO path
This patch cleans up parameters on IO paths.
The key idea is to use f2fs_io_info adding a parameter, block address, and then
use this structure as parameters.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-01-09 17:02:23 -08:00
Chao Yu 3fa06d7bc9 f2fs: readahead contiguous current summary blocks in checkpoint
Let's add readahead code for reading contiguous compact/normal summary blocks
in checkpoint, then we will gain better performance in mount procedure.

Changes from v1
  o remove inappropriate 'unlikely' in npages_for_summary_flush.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-01-09 17:02:23 -08:00
Jaegeuk Kim 042b7816aa f2fs: remove unnecessary call to invalidate inmemory pages
Now we use inmemory pages for atomic write only and provide abort procedure,
we don't need to truncate them explicitly.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-01-09 17:02:22 -08:00
Jaegeuk Kim 1e84371ffe f2fs: change atomic and volatile write policies
This patch adds two new ioctls to release inmemory pages grabbed by atomic
writes.
 o f2fs_ioc_abort_volatile_write
  - If transaction was failed, all the grabbed pages and data should be written.
 o f2fs_ioc_release_volatile_write
  - This is to enhance the performance of PERSIST mode in sqlite.

In order to avoid huge memory consumption which causes OOM, this patch changes
volatile writes to use normal dirty pages, instead blocked flushing to the disk
as long as system does not suffer from memory pressure.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-01-09 17:02:22 -08:00
Chao Yu 635aee1fef f2fs: avoid to ra unneeded blocks in recover flow
To improve recovery speed, f2fs try to readahead many contiguous blocks in warm
node segment, but for most time, abnormal power-off do not occur frequently, so
when mount a normal power-off f2fs image, by contrary ra so many blocks and then
invalid them will hurt the performance of mount.
It's better to just ra the first next-block for normal condition.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-12-08 14:19:09 -08:00
Chao Yu 03e14d522e f2fs: use atomic for counting inode with inline_{dir,inode} flag
As inline_{dir,inode} stat is increased/decreased concurrently by multi threads,
so the value is not so accurate, let's use atomic type for counting accurately.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-12-08 10:54:59 -08:00
Jaegeuk Kim 8dcf2ff721 f2fs: count the number of inmemory pages
This patch adds counting # of inmemory pages in the page cache.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-12-08 10:35:15 -08:00
Jaegeuk Kim 9be32d72be f2fs: do retry operations with cond_resched
This patch revists retrial paths in f2fs.
The basic idea is to use cond_resched instead of retrying from the very early
stage.

Suggested-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-12-08 10:35:05 -08:00
Jaegeuk Kim 8b26ef98da f2fs: use rw_semaphore for nat entry lock
Previoulsy, we used rwlock for nat_entry lock.
But, now we have a lot of complex operations in set_node_addr.
(e.g., allocating kernel memories, handling radix_trees, and so on)

So, this patches tries to change spinlock to rw_semaphore to give CPUs to other
threads.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-12-03 21:23:29 -08:00
Jaegeuk Kim 9486ba442b f2fs: introduce f2fs_dentry_kunmap to clean up
This patch introduces f2fs_dentry_kunmap to clean up dirty codes.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-23 21:51:53 -08:00
Chao Yu 67298804f3 f2fs: introduce struct inode_management to wrap inner fields
Now in f2fs, we have three inode cache: ORPHAN_INO, APPEND_INO, UPDATE_INO,
and we manage fields related to inode cache separately in struct f2fs_sb_info
for each inode cache type.
This makes codes a bit messy, so that this patch intorduce a new struct
inode_management to wrap inner fields as following which make codes more neat.

/* for inner inode cache management */
struct inode_management {
	struct radix_tree_root ino_root;	/* ino entry array */
	spinlock_t ino_lock;			/* for ino entry lock */
	struct list_head ino_list;		/* inode list head */
	unsigned long ino_num;			/* number of entries */
};

struct f2fs_sb_info {
	...
	struct inode_management im[MAX_INO_ENTRY];      /* manage inode cache */
	...
}

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-19 22:49:32 -08:00
Jaegeuk Kim 8c402946f0 f2fs: introduce the number of inode entries
This patch adds to monitor the number of ino entries.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-06 15:17:43 -08:00
Jaegeuk Kim d5053a34a9 f2fs: introduce -o fastboot for reducing booting time only
If a system wants to reduce the booting time as a top priority, now we can
use a mount option, -o fastboot.
With this option, f2fs conducts a little bit slow write_checkpoint, but
it can avoid the node page reads during the next mount time.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-04 17:34:15 -08:00
Jaegeuk Kim 6a8f8ca582 f2fs: avoid race condition in handling wait_io
__submit_merged_bio    f2fs_write_end_io        f2fs_write_end_io
                       wait_io = X              wait_io = x
                       complete(X)              complete(X)
                       wait_io = NULL
wait_for_completion()
free(X)
                                                 spin_lock(X)
                                                 kernel panic

In order to avoid this, this patch removes the wait_io facility.
Instead, we can use wait_on_all_pages_writeback(sbi) to wait for end_ios.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-04 17:34:14 -08:00
Jaegeuk Kim b3d208f96d f2fs: revisit inline_data to avoid data races and potential bugs
This patch simplifies the inline_data usage with the following rule.
1. inline_data is set during the file creation.
2. If new data is requested to be written ranges out of inline_data,
 f2fs converts that inode permanently.
3. There is no cases which converts non-inline_data inode to inline_data.
4. The inline_data flag should be changed under inode page lock.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-04 17:34:11 -08:00
Gu Zheng 52aca07425 f2fs: rename f2fs_set/clear_bit to f2fs_test_and_set/clear_bit
Rename f2fs_set/clear_bit to f2fs_test_and_set/clear_bit, which mean
set/clear bit and return the old value, for better readability.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-03 16:07:36 -08:00
Gu Zheng c6ac4c0ec4 f2fs: introduce f2fs_change_bit to simplify the change bit logic
Introduce f2fs_change_bit to simplify the change bit logic in
function set_to_next_nat{sit}.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-03 16:07:36 -08:00
Gu Zheng fa528722d0 f2fs: remove the redundant function cond_clear_inode_flag
Use clear_inode_flag to replace the redundant cond_clear_inode_flag.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-03 16:07:36 -08:00
Jaegeuk Kim 062a3e7ba7 f2fs: reuse make_empty_dir code for inline_dentry
This patch introduces do_make_empty_dir to mitigate code redundancy
for inline_dentry.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-03 16:07:34 -08:00
Jaegeuk Kim 7b3cd7d6f0 f2fs: introduce f2fs_dentry_ptr structure for code clean-up
This patch introduces f2fs_dentry_ptr structure for the use of a function
parameter in inline_dentry operations.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-03 16:07:34 -08:00
Jaegeuk Kim 38594de767 f2fs: reuse core function in f2fs_readdir for inline_dentry
This patch introduces a core function, f2fs_fill_dentries, to remove
redundant code in f2fs_readdir and f2fs_read_inline_dir.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-03 16:07:34 -08:00
Jaegeuk Kim 3289c061c5 f2fs: add stat info for inline_dentry inodes
This patch adds status information for inline_dentry inodes.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-03 16:07:33 -08:00
Jaegeuk Kim bce8d11207 f2fs: avoid deadlock on init_inode_metadata
Previously, init_inode_metadata does not hold any parent directory's inode
page. So, f2fs_init_acl can grab its parent inode page without any problem.
But, when we use inline_dentry, that page is grabbed during f2fs_add_link,
so that we can fall into deadlock condition like below.

INFO: task mknod:11006 blocked for more than 120 seconds.
      Tainted: G           OE  3.17.0-rc1+ #13
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
mknod           D ffff88003fc94580     0 11006  11004 0x00000000
 ffff880007717b10 0000000000000002 ffff88003c323220 ffff880007717fd8
 0000000000014580 0000000000014580 ffff88003daecb30 ffff88003c323220
 ffff88003fc94e80 ffff88003ffbb4e8 ffff880007717ba0 0000000000000002
Call Trace:
 [<ffffffff8173dc40>] ? bit_wait+0x50/0x50
 [<ffffffff8173d4cd>] io_schedule+0x9d/0x130
 [<ffffffff8173dc6c>] bit_wait_io+0x2c/0x50
 [<ffffffff8173da3b>] __wait_on_bit_lock+0x4b/0xb0
 [<ffffffff811640a7>] __lock_page+0x67/0x70
 [<ffffffff810acf50>] ? autoremove_wake_function+0x40/0x40
 [<ffffffff811652cc>] pagecache_get_page+0x14c/0x1e0
 [<ffffffffa029afa9>] get_node_page+0x59/0x130 [f2fs]
 [<ffffffffa02a63ad>] read_all_xattrs+0x24d/0x430 [f2fs]
 [<ffffffffa02a6ca2>] f2fs_getxattr+0x52/0xe0 [f2fs]
 [<ffffffffa02a7481>] f2fs_get_acl+0x41/0x2d0 [f2fs]
 [<ffffffff8122d847>] get_acl+0x47/0x70
 [<ffffffff8122db5a>] posix_acl_create+0x5a/0x150
 [<ffffffffa02a7759>] f2fs_init_acl+0x29/0xcb [f2fs]
 [<ffffffffa0286a8d>] init_inode_metadata+0x5d/0x340 [f2fs]
 [<ffffffffa029253a>] f2fs_add_inline_entry+0x12a/0x2e0 [f2fs]
 [<ffffffffa0286ea5>] __f2fs_add_link+0x45/0x4a0 [f2fs]
 [<ffffffffa028b5b6>] ? f2fs_new_inode+0x146/0x220 [f2fs]
 [<ffffffffa028b816>] f2fs_mknod+0x86/0xf0 [f2fs]
 [<ffffffff811e3ec1>] vfs_mknod+0xe1/0x160
 [<ffffffff811e4b26>] SyS_mknod+0x1f6/0x200
 [<ffffffff81741d7f>] tracesys+0xe1/0xe6

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-03 16:07:33 -08:00
Jaegeuk Kim 4e6ebf6d49 f2fs: reuse find_in_block code for find_in_inline_dir
This patch removes redundant copied code in find_in_inline_dir.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-03 16:07:32 -08:00
Jaegeuk Kim a82afa2019 f2fs: reuse room_for_filename for inline dentry operation
This patch introduces to reuse the existing room_for_filename for inline dentry
operation.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-03 16:07:32 -08:00
Chao Yu 201a05be96 f2fs: add key function to handle inline dir
Adds Functions to implement inline dir init/lookup/insert/delete/convert ops.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: remove needless reserved area copy, pointed by Dan Carpenter]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-03 16:07:31 -08:00
Chao Yu dbeacf02eb f2fs: export dir operations for inline dir
This patch exports some dir operations for inline dir, additionally introduces
f2fs_drop_nlink from f2fs_delete_entry for reusing by inline dir function.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-03 16:07:31 -08:00
Chao Yu 34d67debe0 f2fs: add infra struct and helper for inline dir
This patch defines macro/inline dentry structure, and adds some helpers for
inline dir infrastructure.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-03 16:07:31 -08:00
Jaegeuk Kim cbcb2872e3 f2fs: invalidate inmemory page
If user truncates file's data, we should truncate inmemory pages too.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-03 16:07:29 -08:00
Jaegeuk Kim 34ba94bac9 f2fs: do not make dirty any inmemory pages
This patch let inmemory pages be clean all the time.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-03 16:07:29 -08:00
Jaegeuk Kim 02a1335f25 f2fs: support volatile operations for transient data
This patch adds support for volatile writes which keep data pages in memory
until f2fs_evict_inode is called by iput.

For instance, we can use this feature for the sqlite database as follows.
While supporting atomic writes for main database file, we can keep its journal
data temporarily in the page cache by the following sequence.

1. open
 -> ioctl(F2FS_IOC_START_VOLATILE_WRITE);
2. writes
 : keep all the data in the page cache.
3. flush to the database file with atomic writes
  a. ioctl(F2FS_IOC_START_ATOMIC_WRITE);
  b. writes
  c. ioctl(F2FS_IOC_COMMIT_ATOMIC_WRITE);
4. close
 -> drop the cached data

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-10-07 11:54:41 -07:00
Jaegeuk Kim 88b88a6679 f2fs: support atomic writes
This patch introduces a very limited functionality for atomic write support.
In order to support atomic write, this patch adds two ioctls:
 o F2FS_IOC_START_ATOMIC_WRITE
 o F2FS_IOC_COMMIT_ATOMIC_WRITE

The database engine should be aware of the following sequence.
1. open
 -> ioctl(F2FS_IOC_START_ATOMIC_WRITE);
2. writes
  : all the written data will be treated as atomic pages.
3. commit
 -> ioctl(F2FS_IOC_COMMIT_ATOMIC_WRITE);
  : this flushes all the data blocks to the disk, which will be shown all or
  nothing by f2fs recovery procedure.
4. repeat to #2.

The IO pattens should be:

  ,- START_ATOMIC_WRITE                  ,- COMMIT_ATOMIC_WRITE
 CP | D D D D D D | FSYNC | D D D D | FSYNC ...
                      `- COMMIT_ATOMIC_WRITE

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-10-06 17:39:50 -07:00