In this round, we've tried to address some performance issues in f2fs_checkpoint
and direct IO flows. Also, there was a work to enhance the page cache management
used for compression. Other than them, we've done typical work including sysfs,
code clean-ups, tracepoint, sanity check, in addition to bug fixes on corner
cases.
Enhancement:
- use iomap for direct IO
- try to avoid lock contention to improve f2fs_ckpt speed
- avoid unnecessary memory allocation in compression flow
- POSIX_FADV_DONTNEED drops the page cache containing compression pages
- add some sysfs entries (gc_urgent_high_remaining, pending_discard)
Bug fix:
- try not to expose unwritten blocks to user by DIO
: this was added to avoid merge conflict; another patch is coming to address
other missing case.
- relax minor error condition for file pinning feature used in Android OTA
- fix potential deadlock case in compression flow
- should not truncate any block on pinned file
In addition, we've done some code clean-ups and tracepoint/sanity check
improvement.
-----BEGIN PGP SIGNATURE-----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=LCJH
-----END PGP SIGNATURE-----
Merge tag 'f2fs-for-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
Pull f2fs updates from Jaegeuk Kim:
"In this round, we've tried to address some performance issues in
f2fs_checkpoint and direct IO flows. Also, there was a work to enhance
the page cache management used for compression. Other than them, we've
done typical work including sysfs, code clean-ups, tracepoint, sanity
check, in addition to bug fixes on corner cases.
Enhancements:
- use iomap for direct IO
- try to avoid lock contention to improve f2fs_ckpt speed
- avoid unnecessary memory allocation in compression flow
- POSIX_FADV_DONTNEED drops the page cache containing compression
pages
- add some sysfs entries (gc_urgent_high_remaining, pending_discard)
Bug fixes:
- try not to expose unwritten blocks to user by DIO (this was added
to avoid merge conflict; another patch is coming to address other
missing case)
- relax minor error condition for file pinning feature used in
Android OTA
- fix potential deadlock case in compression flow
- should not truncate any block on pinned file
In addition, we've done some code clean-ups and tracepoint/sanity
check improvement"
* tag 'f2fs-for-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (29 commits)
f2fs: do not allow partial truncation on pinned file
f2fs: remove redunant invalidate compress pages
f2fs: Simplify bool conversion
f2fs: don't drop compressed page cache in .{invalidate,release}page
f2fs: fix to reserve space for IO align feature
f2fs: fix to check available space of CP area correctly in update_ckpt_flags()
f2fs: support fault injection to f2fs_trylock_op()
f2fs: clean up __find_inline_xattr() with __find_xattr()
f2fs: fix to do sanity check on last xattr entry in __f2fs_setxattr()
f2fs: do not bother checkpoint by f2fs_get_node_info
f2fs: avoid down_write on nat_tree_lock during checkpoint
f2fs: compress: fix potential deadlock of compress file
f2fs: avoid EINVAL by SBI_NEED_FSCK when pinning a file
f2fs: add gc_urgent_high_remaining sysfs node
f2fs: fix to do sanity check in is_alive()
f2fs: fix to avoid panic in is_alive() if metadata is inconsistent
f2fs: fix to do sanity check on inode type during garbage collection
f2fs: avoid duplicate call of mark_inode_dirty
f2fs: show number of pending discard commands
f2fs: support POSIX_FADV_DONTNEED drop compressed page cache
...
Various places in the kernel - largely in filesystems - respond to a
memory allocation failure by looping around and re-trying. Some of
these cannot conveniently use __GFP_NOFAIL, for reasons such as:
- a GFP_ATOMIC allocation, which __GFP_NOFAIL doesn't work on
- a need to check for the process being signalled between failures
- the possibility that other recovery actions could be performed
- the allocation is quite deep in support code, and passing down an
extra flag to say if __GFP_NOFAIL is wanted would be clumsy.
Many of these currently use congestion_wait() which (in almost all
cases) simply waits the given timeout - congestion isn't tracked for
most devices.
It isn't clear what the best delay is for loops, but it is clear that
the various filesystems shouldn't be responsible for choosing a timeout.
This patch introduces memalloc_retry_wait() with takes on that
responsibility. Code that wants to retry a memory allocation can call
this function passing the GFP flags that were used. It will wait
however is appropriate.
For now, it only considers __GFP_NORETRY and whatever
gfpflags_allow_blocking() tests. If blocking is allowed without
__GFP_NORETRY, then alloc_page either made some reclaim progress, or
waited for a while, before failing. So there is no need for much
further waiting. memalloc_retry_wait() will wait until the current
jiffie ends. If this condition is not met, then alloc_page() won't have
waited much if at all. In that case memalloc_retry_wait() waits about
200ms. This is the delay that most current loops uses.
linux/sched/mm.h needs to be included in some files now,
but linux/backing-dev.h does not.
Link: https://lkml.kernel.org/r/163754371968.13692.1277530886009912421@noble.neil.brown.name
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch tries to mitigate lock contention between f2fs_write_checkpoint and
f2fs_get_node_info along with nat_tree_lock.
The idea is, if checkpoint is currently running, other threads that try to grab
nat_tree_lock would be better to wait for checkpoint.
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Added a new sysfs node called gc_urgent_high_remaining. The user can
set the trial count limit for GC urgent high mode with this value. If
GC thread gets to the limit, the mode will turn back to GC normal mode.
By default, the value is zero, which means there is no limit like before.
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In fuzzed image, SSA table may indicate that a data block belongs to
invalid node, which node ID is out-of-range (0, 1, 2 or max_nid), in
order to avoid migrating inconsistent data in such corrupted image,
let's do sanity check anyway before data block migration.
Cc: stable@vger.kernel.org
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
As report by Wenqing Liu in bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=215231
If we enable CONFIG_F2FS_CHECK_FS config, and with fuzzed image attached
in above link, we will encounter panic when executing below script:
1. mkdir mnt
2. mount -t f2fs tmp1.img mnt
3. touch tmp
F2FS-fs (loop11): mismatched blkaddr 5765 (source_blkaddr 1) in seg 3
kernel BUG at fs/f2fs/gc.c:1042!
do_garbage_collect+0x90f/0xa80 [f2fs]
f2fs_gc+0x294/0x12a0 [f2fs]
f2fs_balance_fs+0x2c5/0x7d0 [f2fs]
f2fs_create+0x239/0xd90 [f2fs]
lookup_open+0x45e/0xa90
open_last_lookups+0x203/0x670
path_openat+0xae/0x490
do_filp_open+0xbc/0x160
do_sys_openat2+0x2f1/0x500
do_sys_open+0x5e/0xa0
__x64_sys_openat+0x28/0x40
Previously, f2fs tries to catch data inconcistency exception in between
SSA and SIT table during GC, however once the exception is caught, it will
call f2fs_bug_on to hang kernel, it's not needed, instead, let's set
SBI_NEED_FSCK flag and skip migrating current block.
Fixes: bbf9f7d90f ("f2fs: Fix indefinite loop in f2fs_gc()")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
As report by Wenqing Liu in bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=215231
- Overview
kernel NULL pointer dereference triggered in folio_mark_dirty() when mount and operate on a crafted f2fs image
- Reproduce
tested on kernel 5.16-rc3, 5.15.X under root
1. mkdir mnt
2. mount -t f2fs tmp1.img mnt
3. touch tmp
4. cp tmp mnt
F2FS-fs (loop0): sanity_check_inode: inode (ino=49) extent info [5942, 4294180864, 4] is incorrect, run fsck to fix
F2FS-fs (loop0): f2fs_check_nid_range: out-of-range nid=31340049, run fsck to fix.
BUG: kernel NULL pointer dereference, address: 0000000000000000
folio_mark_dirty+0x33/0x50
move_data_page+0x2dd/0x460 [f2fs]
do_garbage_collect+0xc18/0x16a0 [f2fs]
f2fs_gc+0x1d3/0xd90 [f2fs]
f2fs_balance_fs+0x13a/0x570 [f2fs]
f2fs_create+0x285/0x840 [f2fs]
path_openat+0xe6d/0x1040
do_filp_open+0xc5/0x140
do_sys_openat2+0x23a/0x310
do_sys_open+0x57/0x80
The root cause is for special file: e.g. character, block, fifo or socket file,
f2fs doesn't assign address space operations pointer array for mapping->a_ops field,
so, in a fuzzed image, SSA table indicates a data block belong to special file, when
f2fs tries to migrate that block, it causes NULL pointer access once move_data_page()
calls a_ops->set_dirty_page().
Cc: stable@vger.kernel.org
Reported-by: Wenqing Liu <wenqingliu0120@gmail.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Added two options into "mode=" mount option to make it possible for
developers to simulate filesystem fragmentation/after-GC situation
itself. The developers use these modes to understand filesystem
fragmentation/after-GC condition well, and eventually get some
insights to handle them better.
"fragment:segment": f2fs allocates a new segment in ramdom position.
With this, we can simulate the after-GC condition.
"fragment:block" : We can scatter block allocation with
"max_fragment_chunk" and "max_fragment_hole" sysfs
nodes. f2fs will allocate 1..<max_fragment_chunk>
blocks in a chunk and make a hole in the length of
1..<max_fragment_hole> by turns in a newly allocated
free segment. Plus, this mode implicitly enables
"fragment:segment" option for more randomness.
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
There is a missing place we forgot to account .skipped_gc_rwsem, fix it.
Fixes: 6f8d445506 ("f2fs: avoid fi->i_gc_rwsem[WRITE] lock in f2fs_gc")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Added F2FS_IOSTAT config option to support getting IO statistics through
sysfs and printing out periodic IO statistics tracepoint events and
moved I/O statistics related codes into separate files for better
maintenance.
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
[Jaegeuk Kim: set default=y]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch supports to inject fault into f2fs_kmem_cache_alloc().
Usage:
a) echo 32768 > /sys/fs/f2fs/<dev>/inject_type or
b) mount -o fault_type=32768 <dev> <mountpoint>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Added gc_reclaimed_segments and gc_segment_mode sysfs nodes.
1) "gc_reclaimed_segments" shows how many segments have been
reclaimed by GC during a specific GC mode.
2) "gc_segment_mode" is used to control for which gc mode
the "gc_reclaimed_segments" node shows.
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch removes setting SBI_NEED_FSCK when GC gets an error on f2fs_iget,
since f2fs_iget can give ENOMEM and others by race condition.
If we set this critical fsck flag, we'll get EIO during fsync via the below
code path.
In f2fs_inplace_write_data(),
if (is_sbi_flag_set(sbi, SBI_NEED_FSCK) || f2fs_cp_error(sbi)) {
err = -EIO;
goto drop_bio;
}
Fixes: 9557727876 ("f2fs: drop inplace IO if fs status is abnormal")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Support to use address space of inner inode to cache compressed block,
in order to improve cache hit ratio of random read.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Update the logging uses that have unnecessary newlines as the f2fs_printk
function and so its f2fs_<level> macro callers already adds one.
This allows searching single line logging entries with an easier grep and
also avoids unnecessary blank lines in the logging.
Miscellanea:
o Coalesce formats
o Align to open parenthesis
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Default age threshold value is missed to set, fix it.
Fixes: 093749e296 ("f2fs: support age threshold based garbage collection")
Reported-by: Sahitya Tummala <stummala@codeaurora.org>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Restruct f2fs page private layout for below reasons:
There are some cases that f2fs wants to set a flag in a page to
indicate a specified status of page:
a) page is in transaction list for atomic write
b) page contains dummy data for aligned write
c) page is migrating for GC
d) page contains inline data for inline inode flush
e) page belongs to merkle tree, and is verified for fsverity
f) page is dirty and has filesystem/inode reference count for writeback
g) page is temporary and has decompress io context reference for compression
There are existed places in page structure we can use to store
f2fs private status/data:
- page.flags: PG_checked, PG_private
- page.private
However it was a mess when we using them, which may cause potential
confliction:
page.private PG_private PG_checked page._refcount (+1 at most)
a) -1 set +1
b) -2 set
c), d), e) set
f) 0 set +1
g) pointer set
The other problem is page.flags has no free slot, if we can avoid set
zero to page.private and set PG_private flag, then we use non-zero value
to indicate PG_private status, so that we may have chance to reclaim
PG_private slot for other usage. [1]
The other concern is f2fs has bad scalability in aspect of indicating
more page status.
So in this patch, let's restructure f2fs' page.private as below to
solve above issues:
Layout A: lowest bit should be 1
| bit0 = 1 | bit1 | bit2 | ... | bit MAX | private data .... |
bit 0 PAGE_PRIVATE_NOT_POINTER
bit 1 PAGE_PRIVATE_ATOMIC_WRITE
bit 2 PAGE_PRIVATE_DUMMY_WRITE
bit 3 PAGE_PRIVATE_ONGOING_MIGRATION
bit 4 PAGE_PRIVATE_INLINE_INODE
bit 5 PAGE_PRIVATE_REF_RESOURCE
bit 6- f2fs private data
Layout B: lowest bit should be 0
page.private is a wrapped pointer.
After the change:
page.private PG_private PG_checked page._refcount (+1 at most)
a) 11 set +1
b) 101 set +1
c) 1001 set +1
d) 10001 set +1
e) set
f) 100001 set +1
g) pointer set +1
[1] https://lore.kernel.org/linux-f2fs-devel/20210422154705.GO3596236@casper.infradead.org/T/#u
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch combined the below three clean-up patches.
- modify open brace '{' following function definitions
- ERROR: spaces required around that ':'
- ERROR: spaces required before the open parenthesis '('
- ERROR: spaces prohibited before that ','
- Made suggested modifications from checkpatch in reference to WARNING:
Missing a blank line after declarations
Signed-off-by: Yi Zhuang <zhuangyi1@huawei.com>
Signed-off-by: Jia Yang <jiayang5@huawei.com>
Signed-off-by: Jack Qiu <jack.qiu@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In this patch, we will add two new mount options: "gc_merge" and
"nogc_merge", when background_gc is on, "gc_merge" option can be
set to let background GC thread to handle foreground GC requests,
it can eliminate the sluggish issue caused by slow foreground GC
operation when GC is triggered from a process with limited I/O
and CPU resources.
Original idea is from Xiang.
Signed-off-by: Gao Xiang <xiang@kernel.org>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In CP disabling mode, there are two issues when using LFS or SSR | AT_SSR
mode to select victim:
1. LFS is set to find source section during GC, the victim should have
no checkpointed data, since after GC, section could not be set free for
reuse.
Previously, we only check valid chpt blocks in current segment rather
than section, fix it.
2. SSR | AT_SSR are set to find target segment for writes which can be
fully filled by checkpointed and newly written blocks, we should never
select such segment, otherwise it can cause panic or data corruption
during allocation, potential case is described as below:
a) target segment has 'n' (n < 512) ckpt valid blocks
b) GC migrates 'n' valid blocks to other segment (segment is still
in dirty list)
c) GC migrates '512 - n' blocks to target segment (segment has 'n'
cp_vblocks and '512 - n' vblocks)
d) If GC selects target segment via {AT,}SSR allocator, however there
is no free space in targe segment.
Fixes: 4354994f09 ("f2fs: checkpoint disabling")
Fixes: 093749e296 ("f2fs: support age threshold based garbage collection")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
AT_SSR mode is introduced by age threshold based GC for better
hot/cold data seperation and avoiding free segment cost. However,
LFS write mode is preferred in the scenario of foreground or high
urgent GC, which should be finished ASAP. Let's only use AT_SSR
in background GC and not high urgent GC modes.
Signed-off-by: Weichao Guo <guoweichao@oppo.com>
Signed-off-by: Huang Jianan <huangjianan@oppo.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
f2fs_resize_fs() hangs in below callstack with testcase:
- mkfs 16GB image & mount image
- dd 8GB fileA
- dd 8GB fileB
- sync
- rm fileA
- sync
- resize filesystem to 8GB
kernel BUG at segment.c:2484!
Call Trace:
allocate_segment_by_default+0x92/0xf0 [f2fs]
f2fs_allocate_data_block+0x44b/0x7e0 [f2fs]
do_write_page+0x5a/0x110 [f2fs]
f2fs_outplace_write_data+0x55/0x100 [f2fs]
f2fs_do_write_data_page+0x392/0x850 [f2fs]
move_data_page+0x233/0x320 [f2fs]
do_garbage_collect+0x14d9/0x1660 [f2fs]
free_segment_range+0x1f7/0x310 [f2fs]
f2fs_resize_fs+0x118/0x330 [f2fs]
__f2fs_ioctl+0x487/0x3680 [f2fs]
__x64_sys_ioctl+0x8e/0xd0
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The root cause is we forgot to check that whether we have enough space
in resized filesystem to store all valid blocks in before-resizing
filesystem, then allocator will run out-of-space during block migration
in free_segment_range().
Fixes: b4b10061ef ("f2fs: refactor resize_fs to avoid meta updates in progress")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
F2FS_IOC_FLUSH_DEVICE/F2FS_IOC_RESIZE_FS needs to migrate all blocks of
target segment to other place, no matter the segment has partially or fully
valid blocks.
However, after commit 803e74be04 ("f2fs: stop GC when the victim becomes
fully valid"), we may skip migration due to target segment is fully valid,
result in failing the ioctl interface, fix this.
Fixes: 803e74be04 ("f2fs: stop GC when the victim becomes fully valid")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Trival cleanups:
- relocate set_summary() before its use
- relocate "allocate block address" to correct place
- remove unneeded f2fs_wait_on_page_writeback()
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Use rwsem to ensure serialization of the callers and to avoid
starvation of high priority tasks, when the system is under
heavy IO workload.
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
After commit 0b6d4ca04a ("f2fs: don't return vmalloc() memory from
f2fs_kmalloc()"), f2fs_k{m,z}alloc() will not return vmalloc()'ed
memory, so clean up to use kfree() instead of kvfree() to free
vmalloc()'ed memory.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
There are several issues in current background GC algorithm:
- valid blocks is one of key factors during cost overhead calculation,
so if segment has less valid block, however even its age is young or
it locates hot segment, CB algorithm will still choose the segment as
victim, it's not appropriate.
- GCed data/node will go to existing logs, no matter in-there datas'
update frequency is the same or not, it may mix hot and cold data
again.
- GC alloctor mainly use LFS type segment, it will cost free segment
more quickly.
This patch introduces a new algorithm named age threshold based
garbage collection to solve above issues, there are three steps
mainly:
1. select a source victim:
- set an age threshold, and select candidates beased threshold:
e.g.
0 means youngest, 100 means oldest, if we set age threshold to 80
then select dirty segments which has age in range of [80, 100] as
candiddates;
- set candidate_ratio threshold, and select candidates based the
ratio, so that we can shrink candidates to those oldest segments;
- select target segment with fewest valid blocks in order to
migrate blocks with minimum cost;
2. select a target victim:
- select candidates beased age threshold;
- set candidate_radius threshold, search candidates whose age is
around source victims, searching radius should less than the
radius threshold.
- select target segment with most valid blocks in order to avoid
migrating current target segment.
3. merge valid blocks from source victim into target victim with
SSR alloctor.
Test steps:
- create 160 dirty segments:
* half of them have 128 valid blocks per segment
* left of them have 384 valid blocks per segment
- run background GC
Benefit: GC count and block movement count both decrease obviously:
- Before:
- Valid: 86
- Dirty: 1
- Prefree: 11
- Free: 6001 (6001)
GC calls: 162 (BG: 220)
- data segments : 160 (160)
- node segments : 2 (2)
Try to move 41454 blocks (BG: 41454)
- data blocks : 40960 (40960)
- node blocks : 494 (494)
IPU: 0 blocks
SSR: 0 blocks in 0 segments
LFS: 41364 blocks in 81 segments
- After:
- Valid: 87
- Dirty: 0
- Prefree: 4
- Free: 6008 (6008)
GC calls: 75 (BG: 76)
- data segments : 74 (74)
- node segments : 1 (1)
Try to move 12813 blocks (BG: 12813)
- data blocks : 12544 (12544)
- node blocks : 269 (269)
IPU: 0 blocks
SSR: 12032 blocks in 77 segments
LFS: 855 blocks in 2 segments
Signed-off-by: Chao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: fix a bug along with pinfile in-mem segment & clean up]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Don't let f2fs inner GC ruins original aging degree of segment.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Previous implementation of aligned pinfile allocation will:
- allocate new segment on cold data log no matter whether last used
segment is partially used or not, it makes IOs more random;
- force concurrent cold data/GCed IO going into warm data area, it
can make a bad effect on hot/cold data separation;
In this patch, we introduce a new type of log named 'inmem curseg',
the differents from normal curseg is:
- it reuses existed segment type (CURSEG_XXX_NODE/DATA);
- it only exists in memory, its segno, blkofs, summary will not b
persisted into checkpoint area;
With this new feature, we can enhance scalability of log, special
allocators can be created for purposes:
- pure lfs allocator for aligned pinfile allocation or file
defragmentation
- pure ssr allocator for later feature
So that, let's update aligned pinfile allocation to use this new
inmem curseg fwk.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
NVMe Zoned Namespace devices can have zone-capacity less than zone-size.
Zone-capacity indicates the maximum number of sectors that are usable in
a zone beginning from the first sector of the zone. This makes the sectors
sectors after the zone-capacity till zone-size to be unusable.
This patch set tracks zone-size and zone-capacity in zoned devices and
calculate the usable blocks per segment and usable segments per section.
If zone-capacity is less than zone-size mark only those segments which
start before zone-capacity as free segments. All segments at and beyond
zone-capacity are treated as permanently used segments. In cases where
zone-capacity does not align with segment size the last segment will start
before zone-capacity and end beyond the zone-capacity of the zone. For
such spanning segments only sectors within the zone-capacity are used.
During writes and GC manage the usable segments in a section and usable
blocks per segment. Segments which are beyond zone-capacity are never
allocated, and do not need to be garbage collected, only the segments
which are before zone-capacity needs to garbage collected.
For spanning segments based on the number of usable blocks in that
segment, write to blocks only up to zone-capacity.
Zone-capacity is device specific and cannot be configured by the user.
Since NVMe ZNS device zones are sequentially write only, a block device
with conventional zones or any normal block device is needed along with
the ZNS device for the metadata operations of F2fs.
A typical nvme-cli output of a zoned device shows zone start and capacity
and write pointer as below:
SLBA: 0x0 WP: 0x0 Cap: 0x18800 State: EMPTY Type: SEQWRITE_REQ
SLBA: 0x20000 WP: 0x20000 Cap: 0x18800 State: EMPTY Type: SEQWRITE_REQ
SLBA: 0x40000 WP: 0x40000 Cap: 0x18800 State: EMPTY Type: SEQWRITE_REQ
Here zone size is 64MB, capacity is 49MB, WP is at zone start as the zones
are in EMPTY state. For each zone, only zone start + 49MB is usable area,
any lba/sector after 49MB cannot be read or written to, the drive will fail
any attempts to read/write. So, the second zone starts at 64MB and is
usable till 113MB (64 + 49) and the range between 113 and 128MB is
again unusable. The next zone starts at 128MB, and so on.
Signed-off-by: Aravind Ramesh <aravind.ramesh@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Added a new gc_urgent mode, GC_URGENT_LOW, in which mode
F2FS will lower the bar of checking idle in order to
process outstanding discard commands and GC a little bit
aggressively.
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If f2fs_grab_cache_page() fails, it needs to return -ENOMEM.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
When f2fs_ioc_gc_range performs multiple segments gc ops, the return
value of f2fs_ioc_gc_range is determined by the last segment gc ops.
If its ops failed, the f2fs_ioc_gc_range will be considered to be failed
despite some of previous segments gc ops succeeded. Therefore, so we
fix: Redefine the return value of getting victim ops and add exception
handle for f2fs_gc. In particular, 1).if target has no valid block, it
will go on. 2).if target sectoion has valid block(s), but it is current
section, we will reminder the caller.
Signed-off-by: Qilong Zhang <zhangqilong3@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Use validation of @fio to inidcate whether caller want to serialize IOs
in io.io_list or not, then @add_list will be redundant, remove it.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Assume each section has 4 segment:
.___________________________.
|_Segment0_|_..._|_Segment3_|
. .
. .
.__________.
|_section0_|
Segment 0~2 has 0 valid block, segment 3 has 512 valid blocks.
It will fail if we want to gc section0 in this scenes,
because all 4 segments in section0 is not dirty.
So we should use dirty section bitmap instead of dirty segment bitmap
to get right victim section.
Signed-off-by: Jack Qiu <jack.qiu@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Sahitya raised an issue:
- prevent meta updates while checkpoint is in progress
allocate_segment_for_resize() can cause metapage updates if
it requires to change the current node/data segments for resizing.
Stop these meta updates when there is a checkpoint already
in progress to prevent inconsistent CP data.
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Data flush can generate heavy IO and cause long latency during
flush, so it's not appropriate to trigger it in foreground
operation.
And also, we may face below potential deadlock during data flush:
- f2fs_write_multi_pages
- f2fs_write_raw_pages
- f2fs_write_single_data_page
- f2fs_balance_fs
- f2fs_balance_fs_bg
- f2fs_sync_dirty_inodes
- filemap_fdatawrite -- stuck on flush same cluster
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Fields in struct f2fs_super_block should be updated under coverage
of sb_lock, fix to adjust update_sb_metadata() for that rule.
Fixes: 04f0b2eaa3 ("f2fs: ioctl for removing a range from F2FS")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Even though online resize is successfully done, a SPO immediately
after resize, still causes below error in the next mount.
[ 11.294650] F2FS-fs (sda8): Wrong user_block_count: 2233856
[ 11.300272] F2FS-fs (sda8): Failed to get valid F2FS checkpoint
This is because after FS metadata is updated in update_fs_metadata()
if the SBI_IS_DIRTY is not dirty, then CP will not be done to reflect
the new user_block_count.
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
As Geert Uytterhoeven reported:
for parameter HZ/50 in congestion_wait(BLK_RW_ASYNC, HZ/50);
On some platforms, HZ can be less than 50, then unexpected 0 timeout
jiffies will be set in congestion_wait().
This patch introduces a macro DEFAULT_IO_TIMEOUT to wrap a determinate
value with msecs_to_jiffies(20) to instead HZ/50 to avoid such issue.
Quoted from Geert Uytterhoeven:
"A timeout of HZ means 1 second.
HZ/50 means 20 ms, but has the risk of being zero, if HZ < 50.
If you want to use a timeout of 20 ms, you best use msecs_to_jiffies(20),
as that takes care of the special cases, and never returns 0."
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If first segment is empty and migration_granularity is 1, we can't move this
at all.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
There are three status for background gc: on, off and sync, it's
a little bit confused to use test_opt(BG_GC) and test_opt(FORCE_FG_GC)
combinations to indicate status of background gc.
So let's remove F2FS_MOUNT_BG_GC and F2FS_MOUNT_FORCE_FG_GC mount
options, and add F2FS_OPTION().bggc_mode with below three status
to clean up codes and enhance bggc mode's scalability.
enum {
BGGC_MODE_ON, /* background gc is on */
BGGC_MODE_OFF, /* background gc is off */
BGGC_MODE_SYNC, /*
* background gc is on, migrating blocks
* like foreground gc
*/
};
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch removes F2FS_MOUNT_ADAPTIVE and F2FS_MOUNT_LFS mount options,
and add F2FS_OPTION.fs_mode with below two status to indicate filesystem
mode.
enum {
FS_MODE_ADAPTIVE, /* use both lfs/ssr allocation */
FS_MODE_LFS, /* use lfs allocation only */
};
It can enhance code readability and fs mode's scalability.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
- rename datablock_addr() to data_blkaddr().
- wrap data_blkaddr() with f2fs_data_blkaddr() to clean up
parameters.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
