- rename is_valid_blkaddr() to is_valid_meta_blkaddr() for readability.
- introduce is_valid_blkaddr() for cleanup.
No logic change in this patch.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
For extreme case:
10 section, op = 10%, no_fggc_threshold = 90%
All section usage: 85% 85% 85% 85% 90% 90% 95% 95% 95% 95%
During foreground GC, if we skip select dirty section whose usage
is larger than no_fggc_threshold, we can only recycle 80% invalid
space from four 85% usage sections and two 90% usage sections,
result in encountering out-of-space issue.
This reverts commit e93b986525 to
fix this issue, besides, we keep the logic that we scan all dirty
section when searching a victim, so that GC can select victim with
least valid blocks.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Related to https://lkml.org/lkml/2018/4/8/661
Sometimes, we need to write meta data to new allocated block address,
then we will allocate a zeroed page in inner inode's address space, and
fill partial data in it, and leave other place with zero value which means
some fields are initial status.
There are two inner inodes (meta inode and node inode) setting __GFP_ZERO,
I have just checked them, for both of them, we can avoid using __GFP_ZERO,
and do initialization by ourselves to avoid unneeded/redundant zeroing
from mm.
Cc: <stable@vger.kernel.org>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch check blkaddr more accuratly before issue a
write or read bio.
Signed-off-by: Yunlei He <heyunlei@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If f2fs is running on top of very small devices, it's worth to avoid abusing
free LBAs. In order to achieve that, this patch introduces some parameter
tuning.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch rebuild sit page from sit info in mem instead
of issue a read io.
I test this method and the result is as below:
Pre:
mmc_perf_test-12061 [001] ...1 976.819992: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-12061 [001] ...1 976.856446: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-12061 [003] ...1 998.976946: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-12061 [003] ...1 999.023269: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-12061 [003] ...1 1022.060772: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-12061 [003] ...1 1022.111034: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-12061 [002] ...1 1070.127643: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-12061 [003] ...1 1070.187352: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-12061 [003] ...1 1095.942124: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-12061 [003] ...1 1095.995975: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-12061 [003] ...1 1122.535091: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-12061 [003] ...1 1122.586521: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-12061 [001] ...1 1147.897487: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-12061 [001] ...1 1147.959438: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-12061 [003] ...1 1177.926951: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-12061 [002] ...1 1177.976823: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-12061 [002] ...1 1204.176087: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-12061 [002] ...1 1204.239046: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
Some sit flush consume more than 50ms.
Now:
mmc_perf_test-2187 [007] ...1 196.840684: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [007] ...1 196.841258: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-2187 [007] ...1 219.430582: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [007] ...1 219.431144: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-2187 [002] ...1 243.638678: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [000] ...1 243.638980: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-2187 [002] ...1 265.392180: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [002] ...1 265.392245: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-2187 [000] ...1 290.309051: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [000] ...1 290.309116: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-2187 [003] ...1 317.144209: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [003] ...1 317.145913: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-2187 [005] ...1 343.224954: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [005] ...1 343.225574: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-2187 [000] ...1 370.239846: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [000] ...1 370.241138: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-2187 [001] ...1 397.029043: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [001] ...1 397.030750: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-2187 [003] ...1 425.386377: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [003] ...1 425.387735: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
Most sit flush consume no more than 1ms.
Signed-off-by: Yunlei He <heyunlei@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch splits need_inplace_update to two functions:
a. should_update_inplace() includes all conditions that we must use IPU.
b. should_update_outplace() includes all conditions that we must use OPU.
So that, in f2fs_ioc_set_pin_file() and f2fs_defragment_range(), we can
use corresponding function to check whether we can trigger OPU/IPU or not.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Let's avoid BUG_ON during fill_super, when on-disk was totall corrupted.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
When we are closing to trigger foreground GC, if there are only a few
of dirty metas, we can log these dirty metas in left space of opened
segments instead of triggering foreground GC.
With this patch, total count of foreground GC triggered by
test/generic/* of fstest suit reduce from 254 to 184.
So let's do the check before foreground GC anyway.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
There are some cases user didn't update SIT cache under this lock,
so let's use rw_semaphore instead of mutex to enhance concurrently
accessing.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
There may be extreme case as below:
For one section contains one segment, and there are total 100 segments
with 10% over-privision ratio in f2fs partition, fggc_threshold will
be rounded down to 460 instead of 460.8 as below caclulation:
sbi->fggc_threshold = div_u64((u64)(main_count - ovp_count) *
BLKS_PER_SEC(sbi), (main_count - resv_count));
If section usage is as:
60 segments which contain 460 valid blocks
40 segments which contain 462 valid blocks
As valid block number in all sections is large than fggc_threshold, so
none of them will be chosen as candidate due to incorrect fggc_threshold.
Let's just soften the term of choosing foreground GC candidates.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
There are many different scenarios such as fstrim, umount, urgent or
background where we will issue discards, actually, they need use
different policy in aspect of io aware, discard granularity, delay
interval and so on. But now they just share one common discard policy,
so there will be race when changing policy in between these scenarios,
the interference of changing discard policy will be very serious.
This patch changes to split discard policy for different scenarios.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
We expect cold files write data sequentially, but sometimes some of small data
can be updated, which incurs fragmentation.
Let's avoid that.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In this round, we've added new features such as disk quota and statx, and
modified internal bio management flow to merge more IOs depending on block
types. We've also made internal threads freezeable for Android battery life.
In addition to them, there are some patches to avoid lock contention as well
as a couple of deadlock conditions.
= Enhancement
- support usrquota, grpquota, and statx
- manage DATA/NODE typed bios separately to serialize more IOs
- modify f2fs_lock_op/wio_mutex to avoid lock contention
- prevent lock contention in migratepage
= Bug fix
- miss to load written inode flag
- fix worst case victim selection in GC
- freezeable GC and discard threads for Android battery life
- sanitize f2fs metadata to deal with security hole
- clean up sysfs-related code and docs
-----BEGIN PGP SIGNATURE-----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=N4GZ
-----END PGP SIGNATURE-----
Merge tag 'for-f2fs-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
Pull f2fs updates from Jaegeuk Kim:
"In this round, we've added new features such as disk quota and statx,
and modified internal bio management flow to merge more IOs depending
on block types. We've also made internal threads freezeable for
Android battery life. In addition to them, there are some patches to
avoid lock contention as well as a couple of deadlock conditions.
Enhancements:
- support usrquota, grpquota, and statx
- manage DATA/NODE typed bios separately to serialize more IOs
- modify f2fs_lock_op/wio_mutex to avoid lock contention
- prevent lock contention in migratepage
Bug fixes:
- fix missing load of written inode flag
- fix worst case victim selection in GC
- freezeable GC and discard threads for Android battery life
- sanitize f2fs metadata to deal with security hole
- clean up sysfs-related code and docs"
* tag 'for-f2fs-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (59 commits)
f2fs: support plain user/group quota
f2fs: avoid deadlock caused by lock order of page and lock_op
f2fs: use spin_{,un}lock_irq{save,restore}
f2fs: relax migratepage for atomic written page
f2fs: don't count inode block in in-memory inode.i_blocks
Revert "f2fs: fix to clean previous mount option when remount_fs"
f2fs: do not set LOST_PINO for renamed dir
f2fs: do not set LOST_PINO for newly created dir
f2fs: skip ->writepages for {mete,node}_inode during recovery
f2fs: introduce __check_sit_bitmap
f2fs: stop gc/discard thread in prior during umount
f2fs: introduce reserved_blocks in sysfs
f2fs: avoid redundant f2fs_flush after remount
f2fs: report # of free inodes more precisely
f2fs: add ioctl to do gc with target block address
f2fs: don't need to check encrypted inode for partial truncation
f2fs: measure inode.i_blocks as generic filesystem
f2fs: set CP_TRIMMED_FLAG correctly
f2fs: require key for truncate(2) of encrypted file
f2fs: move sysfs code from super.c to fs/f2fs/sysfs.c
...
Split DATA/NODE type bio cache according to different temperature,
so write IOs with the same temperature can be merged in corresponding
bio cache as much as possible, otherwise, different temperature write
IOs submitting into one bio cache will always cause split of bio.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Merge more updates from Andrew Morton:
- the rest of MM
- various misc things
- procfs updates
- lib/ updates
- checkpatch updates
- kdump/kexec updates
- add kvmalloc helpers, use them
- time helper updates for Y2038 issues. We're almost ready to remove
current_fs_time() but that awaits a btrfs merge.
- add tracepoints to DAX
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (114 commits)
drivers/staging/ccree/ssi_hash.c: fix build with gcc-4.4.4
selftests/vm: add a test for virtual address range mapping
dax: add tracepoint to dax_insert_mapping()
dax: add tracepoint to dax_writeback_one()
dax: add tracepoints to dax_writeback_mapping_range()
dax: add tracepoints to dax_load_hole()
dax: add tracepoints to dax_pfn_mkwrite()
dax: add tracepoints to dax_iomap_pte_fault()
mtd: nand: nandsim: convert to memalloc_noreclaim_*()
treewide: convert PF_MEMALLOC manipulations to new helpers
mm: introduce memalloc_noreclaim_{save,restore}
mm: prevent potential recursive reclaim due to clearing PF_MEMALLOC
mm/huge_memory.c: deposit a pgtable for DAX PMD faults when required
mm/huge_memory.c: use zap_deposited_table() more
time: delete CURRENT_TIME_SEC and CURRENT_TIME
gfs2: replace CURRENT_TIME with current_time
apparmorfs: replace CURRENT_TIME with current_time()
lustre: replace CURRENT_TIME macro
fs: ubifs: replace CURRENT_TIME_SEC with current_time
fs: ufs: use ktime_get_real_ts64() for birthtime
...
CURRENT_TIME_SEC is not y2038 safe.
Replace use of CURRENT_TIME_SEC with ktime_get_real_seconds in segment
timestamps used by GC algorithm including the segment mtime timestamps.
Link: http://lkml.kernel.org/r/1491613030-11599-2-git-send-email-deepa.kernel@gmail.com
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch introduces encrypt_one_page which encrypts one data page before
submit_bio, and change the use of need_inplace_update.
Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Async request may be throttled in block layer, so page for async may keep WRITE_BACK
for a long time.
For encrytped inode, we need wait on page writeback no matter if the device supports
BDI_CAP_STABLE_WRITES. This may result in a higher waiting page writeback time for
async encrypted inode page.
This patch skips IPU for encrypted inode's updating write.
Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch adds an ioctl to flush data in faster device to cold area. User can
give device number and number of segments to move. It doesn't move it if there
is only one device.
The parameter looks like:
struct f2fs_flush_device {
u32 dev_num; /* device number to flush */
u32 segments; /* # of segments to flush */
};
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch introduces an ASYNC IPU policy.
Under senario of large # of async updating(e.g. log writing in Android),
disk would be seriously fragmented, and higher frequent gc would be triggered.
This patch uses IPU to rewrite the async update writting, since async is
NOT sensitive to io latency.
Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Add braces around variables used within macros for those make sense
to do it. Many of the macros in f2fs already do this. What this commit
doesn't do is anything that changes line# as a result of adding braces,
which usually affects the binary via __LINE__.
Confirmed no diff in fs/f2fs/f2fs.ko before/after this commit on x86_64,
to make sure this has no functional change as well as there's been no
unexpected side effect due to callers' arithmetics within the existing
code.
Signed-off-by: Tomohiro Kusumi <tkusumi@tuxera.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
It would better split small and large IOs separately in order to get more
consecutive big writes.
The default threshold is set to 64KB, but configurable by sysfs/min_hot_blocks.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
For foreground gc, greedy algorithm should be adapted, which makes
this formula work well:
(2 * (100 / config.overprovision + 1) + 6)
But currently, we fg_gc have a prior to select bg_gc victim segments to gc
first, these victims are selected by cost-benefit algorithm, we can't guarantee
such segments have the small valid blocks, which may destroy the f2fs rule, on
the worstest case, would consume all the free segments.
This patch fix this by add a filter in check_bg_victims, if segment's has # of
valid blocks over overprovision ratio, skip such segments.
Cc: <stable@vger.kernel.org>
Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch adds a mirror for sit version bitmap, and use it to detect
in-memory bitmap corruption which may be caused by bit-transition of
cache or memory overflow.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch adds a mirror for valid block bitmap, and use it to detect
in-memory bitmap corruption which may be caused by bit-transition of
cache or memory overflow.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch implements IO alignment by filling dummy blocks in DATA and NODE
write bios. If we can guarantee, for example, 32KB or 64KB for such the IOs,
we can eliminate underlying dummy page problem which FTL conducts in order to
close MLC or TLC partial written pages.
Note that,
- it requires "-o mode=lfs".
- IO size should be power of 2, not exceed BIO_MAX_PAGES, 256.
- read IO is still 4KB.
- do checkpoint at fsync, if dummy NODE page was written.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Previous mkfs.f2fs allows small partition inappropriately, so f2fs should detect
that as well.
Refer this in f2fs-tools.
mkfs.f2fs: detect small partition by overprovision ratio and # of segments
Reported-and-Tested-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If there are a lot of dirty inodes, we need to flush all of them when doing
checkpoint. So, we need to count this for enough free space.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In 1TB storage, we need to admit 22841 prefree segments, which can consume
too much segments.
This patch sets 8GB in max. prefree segments in that case.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This mount option is to enable original log-structured filesystem forcefully.
So, there should be no random writes for main area.
Especially, this supports host-managed SMR device.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
For data pages, let's try to flush as much as possible in background.
On /dev/pmem0,
1. dd if=/dev/zero of=/mnt/test/testfile bs=1M count=2048 conv=fsync
Before : 800 MB/s
After : 1.1 GB/s
2. dd if=/dev/zero of=/mnt/test/testfile bs=1M count=2048
Before : 1.3 GB/s
After : 2.2 GB/s
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Restructure struct seg_entry to eliminate holes in it, after that,
in 32-bits machine, it reduces size from 32 bytes to 24 bytes; in
64-bits machine, it reduces size from 56 bytes to 40 bytes.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In curseg cache, f2fs caches two different parts:
- datas of current summay block, i.e. summary entries, footer info.
- journal info, i.e. sparse nat/sit entries or io stat info.
With this approach, 1) it may cause higher lock contention when we access
or update both of the parts of cache since we use the same mutex lock
curseg_mutex to protect the cache. 2) current summary block with last
journal info will be writebacked into device as a normal summary block
when flushing, however, we treat journal info as valid one only in current
summary, so most normal summary blocks contain junk journal data, it wastes
remaining space of summary block.
So, in order to fix above issues, we split curseg cache into two parts:
a) current summary block, protected by original mutex lock curseg_mutex
b) journal cache, protected by newly introduced r/w semaphore journal_rwsem
When loading curseg cache during ->mount, we store summary info and
journal info into different caches; When doing checkpoint, we combine
datas of two cache into current summary block for persisting.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk 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: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
