Commit Graph

969002 Commits

Author SHA1 Message Date
Gao Xiang
fd75d0fb19 erofs: reserve physical_clusterbits[]
Formal big pcluster design is actually more powerful / flexable than
the previous thought whose pclustersize was fixed as power-of-2 blocks,
which was obviously inefficient and space-wasting. Instead, pclustersize
can now be set independently for each pcluster, so various pcluster
sizes can also be used together in one file if mkfs wants (for example,
according to data type and/or compression ratio).

Let's get rid of previous physical_clusterbits[] setting (also notice
that corresponding on-disk fields are still 0 for now). Therefore,
head1/2 can be used for at most 2 different algorithms in one file and
again pclustersize is now independent of these.

Link: https://lore.kernel.org/r/20210407043927.10623-2-xiang@kernel.org
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:33:39 -07:00
Ruiqi Gong
377bae60d0 erofs: Clean up spelling mistakes found in fs/erofs
zmap.c: s/correspoinding/corresponding
zdata.c: s/endding/ending

Link: https://lore.kernel.org/r/20210331093920.31923-1-gongruiqi1@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Ruiqi Gong <gongruiqi1@huawei.com>
Reviewed-by: Gao Xiang <hsiangkao@redhat.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:33:35 -07:00
Gao Xiang
ad120342b6 erofs: add on-disk compression configurations
Add a bitmap for available compression algorithms and a variable-sized
on-disk table for compression options in preparation for upcoming big
pcluster and LZMA algorithm, which follows the end of super block.

To parse the compression options, the bitmap is scanned one by one.
For each available algorithm, there is data followed by 2-byte `length'
correspondingly (it's enough for most cases, or entire fs blocks should
be used.)

With such available algorithm bitmap, kernel itself can also refuse to
mount such filesystem if any unsupported compression algorithm exists.

Note that COMPR_CFGS feature will be enabled with BIG_PCLUSTER.

Link: https://lore.kernel.org/r/20210329100012.12980-1-hsiangkao@aol.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:33:31 -07:00
Gao Xiang
8c8cfb8c3c erofs: introduce on-disk lz4 fs configurations
Introduce z_erofs_lz4_cfgs to store all lz4 configurations.
Currently it's only max_distance, but will be used for new
features later.

Link: https://lore.kernel.org/r/20210329012308.28743-4-hsiangkao@aol.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:33:27 -07:00
Huang Jianan
69fbc0634e erofs: support adjust lz4 history window size
lz4 uses LZ4_DISTANCE_MAX to record history preservation. When
using rolling decompression, a block with a higher compression
ratio will cause a larger memory allocation (up to 64k). It may
cause a large resource burden in extreme cases on devices with
small memory and a large number of concurrent IOs. So appropriately
reducing this value can improve performance.

Decreasing this value will reduce the compression ratio (except
when input_size <LZ4_DISTANCE_MAX). But considering that erofs
currently only supports 4k output, reducing this value will not
significantly reduce the compression benefits.

The maximum value of LZ4_DISTANCE_MAX defined by lz4 is 64k, and
we can only reduce this value. For the old kernel, it just can't
reduce the memory allocation during rolling decompression without
affecting the decompression result.

Link: https://lore.kernel.org/r/20210329012308.28743-3-hsiangkao@aol.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Huang Jianan <huangjianan@oppo.com>
Signed-off-by: Guo Weichao <guoweichao@oppo.com>
[ Gao Xiang: introduce struct erofs_sb_lz4_info for configurations. ]
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:33:23 -07:00
Gao Xiang
5cf3a4cd72 erofs: introduce erofs_sb_has_xxx() helpers
Introduce erofs_sb_has_xxx() to make long checks short, especially
for later big pcluster & LZMA features.

Link: https://lore.kernel.org/r/20210329012308.28743-2-hsiangkao@aol.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:33:20 -07:00
Gao Xiang
aed227860d erofs: add unsupported inode i_format check
If any unknown i_format fields are set (may be of some new incompat
inode features), mark such inode as unsupported.

Just in case of any new incompat i_format fields added in the future.

Link: https://lore.kernel.org/r/20210329003614.6583-1-hsiangkao@aol.com
Fixes: 431339ba90 ("staging: erofs: add inode operations")
Cc: <stable@vger.kernel.org> # 4.19+
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:33:16 -07:00
Yue Hu
90130bc073 erofs: don't use erofs_map_blocks() any more
Currently, erofs_map_blocks() will be called only from
erofs_{bmap, read_raw_page} which are all for uncompressed files.
So, the compression branch in erofs_map_blocks() is pointless. Let's
remove it and use erofs_map_blocks_flatmode() directly. Also update
related comments.

Link: https://lore.kernel.org/r/20210325071008.573-1-zbestahu@gmail.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Yue Hu <huyue2@yulong.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:33:13 -07:00
Gao Xiang
06c42f636e erofs: complete a missing case for inplace I/O
Add a missing case which could cause unnecessary page allocation but
not directly use inplace I/O instead, which increases runtime extra
memory footprint.

The detail is, considering an online file-backed page, the right half
of the page is chosen to be cached (e.g. the end page of a readahead
request) and some of its data doesn't exist in managed cache, so the
pcluster will be definitely kept in the submission chain. (IOWs, it
cannot be decompressed without I/O, e.g., due to the bypass queue).

Currently, DELAYEDALLOC/TRYALLOC cases can be downgraded as NOINPLACE,
and stop online pages from inplace I/O. After this patch, unneeded page
allocations won't be observed in pickup_page_for_submission() then.

Link: https://lore.kernel.org/r/20210321183227.5182-1-hsiangkao@aol.com
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:33:10 -07:00
Huang Jianan
100de3f9d9 erofs: use sync decompression for atomic contexts only
Sync decompression was introduced to get rid of additional kworker
scheduling overhead. But there is no such overhead in non-atomic
contexts. Therefore, it should be better to turn off sync decompression
to avoid the current thread waiting in z_erofs_runqueue.

Link: https://lore.kernel.org/r/20210317035448.13921-3-huangjianan@oppo.com
Reviewed-by: Gao Xiang <hsiangkao@redhat.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Huang Jianan <huangjianan@oppo.com>
Signed-off-by: Guo Weichao <guoweichao@oppo.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:33:06 -07:00
Huang Jianan
0881930cda erofs: use workqueue decompression for atomic contexts only
z_erofs_decompressqueue_endio may not be executed in the atomic
context, for example, when dm-verity is turned on. In this scenario,
data can be decompressed directly to get rid of additional kworker
scheduling overhead.

Link: https://lore.kernel.org/r/20210317035448.13921-2-huangjianan@oppo.com
Reviewed-by: Gao Xiang <hsiangkao@redhat.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Huang Jianan <huangjianan@oppo.com>
Signed-off-by: Guo Weichao <guoweichao@oppo.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:33:02 -07:00
Huang Jianan
e901d97d09 erofs: avoid memory allocation failure during rolling decompression
Currently, err would be treated as io error. Therefore, it'd be
better to ensure memory allocation during rolling decompression
to avoid such io error.

In the long term, we might consider adding another !Uptodate case
for such case.

Link: https://lore.kernel.org/r/20210316031515.90954-1-huangjianan@oppo.com
Reviewed-by: Gao Xiang <hsiangkao@redhat.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Huang Jianan <huangjianan@oppo.com>
Signed-off-by: Guo Weichao <guoweichao@oppo.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:32:58 -07:00
Gao Xiang
1571cef7ef erofs: fix bio->bi_max_vecs behavior change
Martin reported an issue that directory read could be hung on the
latest -rc kernel with some certain image. The root cause is that
commit baa2c7c971 ("block: set .bi_max_vecs as actual allocated
vector number") changes .bi_max_vecs behavior. bio->bi_max_vecs
is set as actual allocated vector number rather than the requested
number now.

Let's avoid using .bi_max_vecs completely instead.

Link: https://lore.kernel.org/r/20210306040438.8084-1-hsiangkao@aol.com
Reported-by: Martin DEVERA <devik@eaxlabs.cz>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
[ Gao Xiang: note that <= 5.11 kernels are not impacted. ]
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:32:47 -07:00
Matthew Wilcox (Oracle)
610664e218 block: Add bio_max_segs
It's often inconvenient to use BIO_MAX_PAGES due to min() requiring the
sign to be the same.  Introduce bio_max_segs() and change BIO_MAX_PAGES to
be unsigned to make it easier for the users.

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-28 10:28:00 -07:00
Gao Xiang
00f982c3a6 erofs: initialized fields can only be observed after bit is set
Currently, although set_bit() & test_bit() pairs are used as a fast-
path for initialized configurations. However, these atomic ops are
actually relaxed forms. Instead, load-acquire & store-release form is
needed to make sure uninitialized fields won't be observed in advance
here (yet no such corresponding bitops so use full barriers instead.)

Link: https://lore.kernel.org/r/20210209130618.15838-1-hsiangkao@aol.com
Fixes: 62dc45979f ("staging: erofs: fix race of initializing xattrs of a inode at the same time")
Fixes: 152a333a58 ("staging: erofs: add compacted compression indexes support")
Cc: <stable@vger.kernel.org> # 5.3+
Reported-by: Huang Jianan <huangjianan@oppo.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:23:31 -07:00
Gao Xiang
169b40a1a5 erofs: fix shift-out-of-bounds of blkszbits
syzbot generated a crafted bitszbits which can be shifted
out-of-bounds[1]. So directly print unsupported blkszbits
instead of blksize.

[1] https://lore.kernel.org/r/000000000000c72ddd05b9444d2f@google.com

Link: https://lore.kernel.org/r/20210120013016.14071-1-hsiangkao@aol.com
Reported-by: syzbot+c68f467cd7c45860e8d4@syzkaller.appspotmail.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:23:27 -07:00
Al Viro
c76119a525 erofs: use %pd instead of messing with ->d_name
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-09-28 10:23:12 -07:00
Huang Jianan
c370f66625 erofs: avoid using generic_block_bmap
Surprisingly, `block' in sector_t indicates the number of
i_blkbits-sized blocks rather than sectors for bmap.

In addition, considering buffer_head limits mapped size to 32-bits,
should avoid using generic_block_bmap.

Link: https://lore.kernel.org/r/20201209115740.18802-1-huangjianan@oppo.com
Fixes: 9da681e017 ("staging: erofs: support bmap")
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Reviewed-by: Gao Xiang <hsiangkao@redhat.com>
Signed-off-by: Huang Jianan <huangjianan@oppo.com>
Signed-off-by: Guo Weichao <guoweichao@oppo.com>
[ Gao Xiang: slightly update the commit message description. ]
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:23:09 -07:00
Gao Xiang
ee264ce710 erofs: force inplace I/O under low memory scenario
Try to forcely switch to inplace I/O under low memory scenario in
order to avoid direct memory reclaim due to cached page allocation.

Link: https://lore.kernel.org/r/20201209123717.12430-1-hsiangkao@aol.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:23:05 -07:00
Gao Xiang
43f037b6c3 erofs: simplify try_to_claim_pcluster()
simplify try_to_claim_pcluster() by directly using cmpxchg() here
(the retry loop caused more overhead.) Also, move the chain loop
detection in and rename it to z_erofs_try_to_claim_pcluster().

Link: https://lore.kernel.org/r/20201208095834.3133565-3-hsiangkao@redhat.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:20:39 -07:00
Gao Xiang
faca09518d erofs: insert to managed cache after adding to pcl
Previously, it could be some concern to call add_to_page_cache_lru()
with page->mapping == Z_EROFS_MAPPING_STAGING (!= NULL).

In contrast, page->private is used instead now, so partially revert
commit 5ddcee1f3a ("erofs: get rid of __stagingpage_alloc helper")
with some adaption for simplicity.

Link: https://lore.kernel.org/r/20201208095834.3133565-2-hsiangkao@redhat.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:20:34 -07:00
Gao Xiang
e74fd4e33a erofs: get rid of magical Z_EROFS_MAPPING_STAGING
Previously, we played around with magical page->mapping for short-lived
temporary pages since we need to identify different types of pages in
the same pcluster but both invalidated and short-lived temporary pages
can have page->mapping == NULL. It was considered as safe because that
temporary pages are all non-LRU / non-movable pages.

This patch tends to use specific page->private to identify short-lived
pages instead so it won't rely on page->mapping anymore. Details are
described in "compress.h" as well.

Link: https://lore.kernel.org/r/20201208095834.3133565-1-hsiangkao@redhat.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:20:30 -07:00
Vladimir Zapolskiy
8cf12c39be erofs: remove a void EROFS_VERSION macro set in Makefile
Since commit 4f761fa253 ("erofs: rename errln/infoln/debugln to
erofs_{err, info, dbg}") the defined macro EROFS_VERSION has no affect,
therefore removing it from the Makefile is a non-functional change.

Link: https://lore.kernel.org/r/20201030122839.25431-1-vladimir@tuxera.com
Reviewed-by: Gao Xiang <hsiangkao@redhat.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Vladimir Zapolskiy <vladimir@tuxera.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2021-09-28 10:20:26 -07:00
Satya Tangirala
1936e155a8 fs: Fix freeze_bdev()/thaw_bdev() accounting of bd_fsfreeze_sb
freeze/thaw_bdev() currently use bdev->bd_fsfreeze_count to infer
whether or not bdev->bd_fsfreeze_sb is valid (it's valid iff
bd_fsfreeze_count is non-zero). thaw_bdev() doesn't nullify
bd_fsfreeze_sb.

But this means a freeze_bdev() call followed by a thaw_bdev() call can
leave bd_fsfreeze_sb with a non-null value, while bd_fsfreeze_count is
zero. If freeze_bdev() is called again, and this time
get_active_super() returns NULL (e.g. because the FS is unmounted),
we'll end up with bd_fsfreeze_count > 0, but bd_fsfreeze_sb is
*untouched* - it stays the same (now garbage) value. A subsequent
thaw_bdev() will decide that the bd_fsfreeze_sb value is legitimate
(since bd_fsfreeze_count > 0), and attempt to use it.

Fix this by always setting bd_fsfreeze_sb to NULL when
bd_fsfreeze_count is successfully decremented to 0 in thaw_sb().
Alternatively, we could set bd_fsfreeze_sb to whatever
get_active_super() returns in freeze_bdev() whenever bd_fsfreeze_count
is successfully incremented to 1 from 0 (which can be achieved cleanly
by moving the line currently setting bd_fsfreeze_sb to immediately
after the "sync:" label, but it might be a little too subtle/easily
overlooked in future).

This fixes the currently panicking xfstests generic/085.

Fixes: 040f04bd2e ("fs: simplify freeze_bdev/thaw_bdev")
Signed-off-by: Satya Tangirala <satyat@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-31 14:49:17 -07:00
Jaegeuk Kim
0961cc984e f2fs: should put a page beyond EOF when preparing a write
The prepare_compress_overwrite() gets/locks a page to prepare a read, and calls
f2fs_read_multi_pages() which checks EOF first. If there's any page beyond EOF,
we unlock the page and set cc->rpages[i] = NULL, which we can't put the page
anymore. This makes page leak, so let's fix by putting that page.

Fixes: a949dc5f2c ("f2fs: compress: fix race condition of overwrite vs truncate")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-31 14:41:32 -07:00
Jaegeuk Kim
09b5f83f7c f2fs: deallocate compressed pages when error happens
In f2fs_write_multi_pages(), f2fs_compress_pages() allocates pages for
compression work in cc->cpages[]. Then, f2fs_write_compressed_pages() initiates
bio submission. But, if there's any error before submitting the IOs like early
f2fs_cp_error(), previously it didn't free cpages by f2fs_compress_free_page().
Let's fix memory leak by putting that just before deallocating cc->cpages.

Fixes: 4c8ff7095b ("f2fs: support data compression")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-31 14:41:28 -07:00
Chao Yu
c533acb2f1 f2fs: enable realtime discard iff device supports discard
Let's only enable realtime discard if and only if device supports
discard functionality.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-30 17:57:56 -07:00
Jaegeuk Kim
bb047775ec f2fs: guarantee to write dirty data when enabling checkpoint back
We must flush all the dirty data when enabling checkpoint back. Let's guarantee
that first by adding a retry logic on sync_inodes_sb(). In addition to that,
this patch adds to flush data in fsync when checkpoint is disabled, which can
mitigate the sync_inodes_sb() failures in advance.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-30 17:57:50 -07:00
Chao Yu
3fed4aded2 f2fs: fix to unmap pages from userspace process in punch_hole()
We need to unmap pages from userspace process before removing pagecache
in punch_hole() like we did in f2fs_setattr().

Similar change:
commit 5e44f8c374 ("ext4: hole-punch use truncate_pagecache_range")

Fixes: fbfa2cc58d ("f2fs: add file operations")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-30 17:57:50 -07:00
Chao Yu
a20c48ec32 f2fs: fix unexpected ENOENT comes from f2fs_map_blocks()
In below path, it will return ENOENT if filesystem is shutdown:

- f2fs_map_blocks
 - f2fs_get_dnode_of_data
  - f2fs_get_node_page
   - __get_node_page
    - read_node_page
     - is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN)
       return -ENOENT
 - force return value from ENOENT to 0

It should be fine for read case, since it indicates a hole condition,
and caller could use .m_next_pgofs to skip the hole and continue the
lookup.

However it may cause confusing for write case, since leaving a hole
there, and said nothing was wrong doesn't help.

There is at least one case from dax_iomap_actor() will complain that,
so fix this in prior to supporting dax in f2fs.

xfstest generic/388 reports below warning:

ubuntu godown: xfstests-induced forced shutdown of /mnt/scratch_f2fs:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 485833 at fs/dax.c:1127 dax_iomap_actor+0x339/0x370
Call Trace:
 iomap_apply+0x1c4/0x7b0
 ? dax_iomap_rw+0x1c0/0x1c0
 dax_iomap_rw+0xad/0x1c0
 ? dax_iomap_rw+0x1c0/0x1c0
 f2fs_file_write_iter+0x5ab/0x970 [f2fs]
 do_iter_readv_writev+0x273/0x2e0
 do_iter_write+0xab/0x1f0
 vfs_iter_write+0x21/0x40
 iter_file_splice_write+0x287/0x540
 do_splice+0x37c/0xa60
 __x64_sys_splice+0x15f/0x3a0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae

ubuntu godown: xfstests-induced forced shutdown of /mnt/scratch_f2fs:
------------[ cut here ]------------
RIP: 0010:dax_iomap_pte_fault.isra.0+0x72e/0x14a0
Call Trace:
 dax_iomap_fault+0x44/0x70
 f2fs_dax_huge_fault+0x155/0x400 [f2fs]
 f2fs_dax_fault+0x18/0x30 [f2fs]
 __do_fault+0x4e/0x120
 do_fault+0x3cf/0x7a0
 __handle_mm_fault+0xa8c/0xf20
 ? find_held_lock+0x39/0xd0
 handle_mm_fault+0x1b6/0x480
 do_user_addr_fault+0x320/0xcd0
 ? rcu_read_lock_sched_held+0x67/0xc0
 exc_page_fault+0x77/0x3f0
 ? asm_exc_page_fault+0x8/0x30
 asm_exc_page_fault+0x1e/0x30

Fixes: 83a3bfdb5a ("f2fs: indicate shutdown f2fs to allow unmount successfully")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-30 17:57:50 -07:00
Chao Yu
fafe5fbb01 f2fs: fix to account missing .skipped_gc_rwsem
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>
2021-08-30 17:57:50 -07:00
Chao Yu
b177568d2a f2fs: adjust unlock order for cleanup
This patch adjusts unlock order of .i_mmap_sem and .i_gc_rwsem for
cleanup.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-30 17:57:50 -07:00
Christian Brauner
9c3a9e03e7 mount: fix mounting of detached mounts onto targets that reside on shared mounts
Creating a series of detached mounts, attaching them to the filesystem,
and unmounting them can be used to trigger an integer overflow in
ns->mounts causing the kernel to block any new mounts in count_mounts()
and returning ENOSPC because it falsely assumes that the maximum number
of mounts in the mount namespace has been reached, i.e. it thinks it
can't fit the new mounts into the mount namespace anymore.

Depending on the number of mounts in your system, this can be reproduced
on any kernel that supportes open_tree() and move_mount() by compiling
and running the following program:

  /* SPDX-License-Identifier: LGPL-2.1+ */

  #define _GNU_SOURCE
  #include <errno.h>
  #include <fcntl.h>
  #include <getopt.h>
  #include <limits.h>
  #include <stdbool.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <sys/mount.h>
  #include <sys/stat.h>
  #include <sys/syscall.h>
  #include <sys/types.h>
  #include <unistd.h>

  /* open_tree() */
  #ifndef OPEN_TREE_CLONE
  #define OPEN_TREE_CLONE 1
  #endif

  #ifndef OPEN_TREE_CLOEXEC
  #define OPEN_TREE_CLOEXEC O_CLOEXEC
  #endif

  #ifndef __NR_open_tree
          #if defined __alpha__
                  #define __NR_open_tree 538
          #elif defined _MIPS_SIM
                  #if _MIPS_SIM == _MIPS_SIM_ABI32        /* o32 */
                          #define __NR_open_tree 4428
                  #endif
                  #if _MIPS_SIM == _MIPS_SIM_NABI32       /* n32 */
                          #define __NR_open_tree 6428
                  #endif
                  #if _MIPS_SIM == _MIPS_SIM_ABI64        /* n64 */
                          #define __NR_open_tree 5428
                  #endif
          #elif defined __ia64__
                  #define __NR_open_tree (428 + 1024)
          #else
                  #define __NR_open_tree 428
          #endif
  #endif

  /* move_mount() */
  #ifndef MOVE_MOUNT_F_EMPTY_PATH
  #define MOVE_MOUNT_F_EMPTY_PATH 0x00000004 /* Empty from path permitted */
  #endif

  #ifndef __NR_move_mount
          #if defined __alpha__
                  #define __NR_move_mount 539
          #elif defined _MIPS_SIM
                  #if _MIPS_SIM == _MIPS_SIM_ABI32        /* o32 */
                          #define __NR_move_mount 4429
                  #endif
                  #if _MIPS_SIM == _MIPS_SIM_NABI32       /* n32 */
                          #define __NR_move_mount 6429
                  #endif
                  #if _MIPS_SIM == _MIPS_SIM_ABI64        /* n64 */
                          #define __NR_move_mount 5429
                  #endif
          #elif defined __ia64__
                  #define __NR_move_mount (428 + 1024)
          #else
                  #define __NR_move_mount 429
          #endif
  #endif

  static inline int sys_open_tree(int dfd, const char *filename, unsigned int flags)
  {
          return syscall(__NR_open_tree, dfd, filename, flags);
  }

  static inline int sys_move_mount(int from_dfd, const char *from_pathname, int to_dfd,
                                   const char *to_pathname, unsigned int flags)
  {
          return syscall(__NR_move_mount, from_dfd, from_pathname, to_dfd, to_pathname, flags);
  }

  static bool is_shared_mountpoint(const char *path)
  {
          bool shared = false;
          FILE *f = NULL;
          char *line = NULL;
          int i;
          size_t len = 0;

          f = fopen("/proc/self/mountinfo", "re");
          if (!f)
                  return 0;

          while (getline(&line, &len, f) > 0) {
                  char *slider1, *slider2;

                  for (slider1 = line, i = 0; slider1 && i < 4; i++)
                          slider1 = strchr(slider1 + 1, ' ');

                  if (!slider1)
                          continue;

                  slider2 = strchr(slider1 + 1, ' ');
                  if (!slider2)
                          continue;

                  *slider2 = '\0';
                  if (strcmp(slider1 + 1, path) == 0) {
                          /* This is the path. Is it shared? */
                          slider1 = strchr(slider2 + 1, ' ');
                          if (slider1 && strstr(slider1, "shared:")) {
                                  shared = true;
                                  break;
                          }
                  }
          }
          fclose(f);
          free(line);

          return shared;
  }

  static void usage(void)
  {
          const char *text = "mount-new [--recursive] <base-dir>\n";
          fprintf(stderr, "%s", text);
          _exit(EXIT_SUCCESS);
  }

  #define exit_usage(format, ...)                              \
          ({                                                   \
                  fprintf(stderr, format "\n", ##__VA_ARGS__); \
                  usage();                                     \
          })

  #define exit_log(format, ...)                                \
          ({                                                   \
                  fprintf(stderr, format "\n", ##__VA_ARGS__); \
                  exit(EXIT_FAILURE);                          \
          })

  static const struct option longopts[] = {
          {"help",        no_argument,            0,      'a'},
          { NULL,         no_argument,            0,       0 },
  };

  int main(int argc, char *argv[])
  {
          int exit_code = EXIT_SUCCESS, index = 0;
          int dfd, fd_tree, new_argc, ret;
          char *base_dir;
          char *const *new_argv;
          char target[PATH_MAX];

          while ((ret = getopt_long_only(argc, argv, "", longopts, &index)) != -1) {
                  switch (ret) {
                  case 'a':
                          /* fallthrough */
                  default:
                          usage();
                  }
          }

          new_argv = &argv[optind];
          new_argc = argc - optind;
          if (new_argc < 1)
                  exit_usage("Missing base directory\n");
          base_dir = new_argv[0];

          if (*base_dir != '/')
                  exit_log("Please specify an absolute path");

          /* Ensure that target is a shared mountpoint. */
          if (!is_shared_mountpoint(base_dir))
                  exit_log("Please ensure that \"%s\" is a shared mountpoint", base_dir);

          dfd = open(base_dir, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
          if (dfd < 0)
                  exit_log("%m - Failed to open base directory \"%s\"", base_dir);

          ret = mkdirat(dfd, "detached-move-mount", 0755);
          if (ret < 0)
                  exit_log("%m - Failed to create required temporary directories");

          ret = snprintf(target, sizeof(target), "%s/detached-move-mount", base_dir);
          if (ret < 0 || (size_t)ret >= sizeof(target))
                  exit_log("%m - Failed to assemble target path");

          /*
           * Having a mount table with 10000 mounts is already quite excessive
           * and shoult account even for weird test systems.
           */
          for (size_t i = 0; i < 10000; i++) {
                  fd_tree = sys_open_tree(dfd, "detached-move-mount",
                                          OPEN_TREE_CLONE |
                                          OPEN_TREE_CLOEXEC |
                                          AT_EMPTY_PATH);
                  if (fd_tree < 0) {
                          fprintf(stderr, "%m - Failed to open %d(detached-move-mount)", dfd);
                          exit_code = EXIT_FAILURE;
                          break;
                  }

                  ret = sys_move_mount(fd_tree, "", dfd, "detached-move-mount", MOVE_MOUNT_F_EMPTY_PATH);
                  if (ret < 0) {
                          if (errno == ENOSPC)
                                  fprintf(stderr, "%m - Buggy mount counting");
                          else
                                  fprintf(stderr, "%m - Failed to attach mount to %d(detached-move-mount)", dfd);
                          exit_code = EXIT_FAILURE;
                          break;
                  }
                  close(fd_tree);

                  ret = umount2(target, MNT_DETACH);
                  if (ret < 0) {
                          fprintf(stderr, "%m - Failed to unmount %s", target);
                          exit_code = EXIT_FAILURE;
                          break;
                  }
          }

          (void)unlinkat(dfd, "detached-move-mount", AT_REMOVEDIR);
          close(dfd);

          exit(exit_code);
  }

and wait for the kernel to refuse any new mounts by returning ENOSPC.
How many iterations are needed depends on the number of mounts in your
system. Assuming you have something like 50 mounts on a standard system
it should be almost instantaneous.

The root cause of this is that detached mounts aren't handled correctly
when source and target mount are identical and reside on a shared mount
causing a broken mount tree where the detached source itself is
propagated which propagation prevents for regular bind-mounts and new
mounts. This ultimately leads to a miscalculation of the number of
mounts in the mount namespace.

Detached mounts created via
open_tree(fd, path, OPEN_TREE_CLONE)
are essentially like an unattached new mount, or an unattached
bind-mount. They can then later on be attached to the filesystem via
move_mount() which calls into attach_recursive_mount(). Part of
attaching it to the filesystem is making sure that mounts get correctly
propagated in case the destination mountpoint is MS_SHARED, i.e. is a
shared mountpoint. This is done by calling into propagate_mnt() which
walks the list of peers calling propagate_one() on each mount in this
list making sure it receives the propagation event.
The propagate_one() functions thereby skips both new mounts and bind
mounts to not propagate them "into themselves". Both are identified by
checking whether the mount is already attached to any mount namespace in
mnt->mnt_ns. The is what the IS_MNT_NEW() helper is responsible for.

However, detached mounts have an anonymous mount namespace attached to
them stashed in mnt->mnt_ns which means that IS_MNT_NEW() doesn't
realize they need to be skipped causing the mount to propagate "into
itself" breaking the mount table and causing a disconnect between the
number of mounts recorded as being beneath or reachable from the target
mountpoint and the number of mounts actually recorded/counted in
ns->mounts ultimately causing an overflow which in turn prevents any new
mounts via the ENOSPC issue.

So teach propagation to handle detached mounts by making it aware of
them. I've been tracking this issue down for the last couple of days and
then verifying that the fix is correct by
unmounting everything in my current mount table leaving only /proc and
/sys mounted and running the reproducer above overnight verifying the
number of mounts counted in ns->mounts. With this fix the counts are
correct and the ENOSPC issue can't be reproduced.

This change will only have an effect on mounts created with the new
mount API since detached mounts cannot be created with the old mount API
so regressions are extremely unlikely.

Link: https://lore.kernel.org/r/20210306101010.243666-1-christian.brauner@ubuntu.com
Fixes: 2db154b3ea ("vfs: syscall: Add move_mount(2) to move mounts around")
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: <stable@vger.kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-08-30 17:57:50 -07:00
Fengnan Chang
07290879f7 f2fs: Don't create discard thread when device doesn't support realtime discard
Don't create discard thread when device doesn't support realtime discard
or user specifies nodiscard mount option.

Signed-off-by: Fengnan Chang <changfengnan@vivo.com>
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-30 17:57:49 -07:00
Chao Yu
5145b2306f f2fs: rebuild nat_bits during umount
If all free_nat_bitmap are available, we can rebuild nat_bits from
free_nat_bitmap entirely during umount, let's make another chance
to reenable nat_bits for image.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-23 13:59:00 -07:00
Daeho Jeong
d95bf22a4d f2fs: introduce periodic iostat io latency traces
Whenever we notice some sluggish issues on our machines, we are always
curious about how well all types of I/O in the f2fs filesystem are
handled. But, it's hard to get this kind of real data. First of all,
we need to reproduce the issue while turning on the profiling tool like
blktrace, but the issue doesn't happen again easily. Second, with the
intervention of any tools, the overall timing of the issue will be
slightly changed and it sometimes makes us hard to figure it out.

So, I added the feature printing out IO latency statistics tracepoint
events, which are minimal things to understand filesystem's I/O related
behaviors, into F2FS_IOSTAT kernel config. With "iostat_enable" sysfs
node on, we can get this statistics info in a periodic way and it
would cause the least overhead.

[samples]
 f2fs_ckpt-254:1-507     [003] ....  2842.439683: f2fs_iostat_latency:
dev = (254,11), iotype [peak lat.(ms)/avg lat.(ms)/count],
rd_data [136/1/801], rd_node [136/1/1704], rd_meta [4/2/4],
wr_sync_data [164/16/3331], wr_sync_node [152/3/648],
wr_sync_meta [160/2/4243], wr_async_data [24/13/15],
wr_async_node [0/0/0], wr_async_meta [0/0/0]

 f2fs_ckpt-254:1-507     [002] ....  2845.450514: f2fs_iostat_latency:
dev = (254,11), iotype [peak lat.(ms)/avg lat.(ms)/count],
rd_data [60/3/456], rd_node [60/3/1258], rd_meta [0/0/1],
wr_sync_data [120/12/2285], wr_sync_node [88/5/428],
wr_sync_meta [52/6/2990], wr_async_data [4/1/3],
wr_async_node [0/0/0], wr_async_meta [0/0/0]

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-23 13:58:56 -07:00
Daeho Jeong
d20508acee f2fs: separate out iostat feature
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>
2021-08-23 13:58:53 -07:00
Chao Yu
32935b532d f2fs: compress: do sanity check on cluster
This patch adds f2fs_sanity_check_cluster() to support doing
sanity check on cluster of compressed file, it will be triggered
from below two paths:

- __f2fs_cluster_blocks()
- f2fs_map_blocks(F2FS_GET_BLOCK_FIEMAP)

And it can detect below three kind of cluster insanity status.

C: COMPRESS_ADDR
N: NULL_ADDR or NEW_ADDR
V: valid blkaddr
*: any value

1. [*|C|*|*]
2. [C|*|C|*]
3. [C|N|N|V]

Signed-off-by: Chao Yu <chao@kernel.org>
[Nathan Chancellor: fix missing inline warning]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-23 13:58:50 -07:00
Yangtao Li
fcf8c77c97 f2fs: fix description about main_blkaddr node
Don't leave a blank line, to keep the style consistent
with other node descriptions.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-23 13:58:47 -07:00
Yangtao Li
35f8bc157f f2fs: convert S_IRUGO to 0444
To fix:
WARNING: Symbolic permissions 'S_IRUGO' are not preferred. Consider using octal permissions '0444'.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-23 13:58:43 -07:00
Chao Yu
717d1e903c f2fs: fix to keep compatibility of fault injection interface
The value of FAULT_* macros and its description in f2fs.rst became
inconsistent, fix this to keep compatibility of fault injection
interface.

Fixes: 67883ade7a ("f2fs: remove FAULT_ALLOC_BIO")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-23 13:58:38 -07:00
Chao Yu
4ab362d8ca f2fs: support fault injection for f2fs_kmem_cache_alloc()
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>
2021-08-23 13:58:38 -07:00
Fengnan Chang
9d05ffd991 f2fs: compress: allow write compress released file after truncate to zero
For compressed file, after release compress blocks, don't allow write
direct, but we should allow write direct after truncate to zero.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Fengnan Chang <changfengnan@vivo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-23 13:58:37 -07:00
Yangtao Li
7a11fe8af9 f2fs: correct comment in segment.h
s/two/three

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-12 14:21:57 -07:00
Yangtao Li
b771a85432 f2fs: improve sbi status info in debugfs/f2fs/status
Do not use numbers but strings to improve readability when flag is set.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-12 14:21:53 -07:00
Fengnan Chang
60a81e6cf3 f2fs: compress: avoid duplicate counting of valid blocks when read compressed file
Since cluster is basic unit of compression, one cluster is compressed or
not, so we can calculate valid blocks only for first page in cluster,
the other pages just skip.

Signed-off-by: Fengnan Chang <changfengnan@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-12 14:21:50 -07:00
Chao Yu
24d236c4fa f2fs: fix to do sanity check for sb/cp fields correctly
This patch fixes below problems of sb/cp sanity check:
- in sanity_check_raw_superi(), it missed to consider log header
blocks while cp_payload check.
- in f2fs_sanity_check_ckpt(), it missed to check nat_bits_blocks.

Cc: <stable@kernel.org>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-12 14:21:46 -07:00
Chao Yu
e2a7d2733b f2fs: avoid unneeded memory allocation in __add_ino_entry()
__add_ino_entry() will allocate slab cache even if we have already
cached ino entry in radix tree, e.g. for case of multiple devices.

Let's check radix tree first under protection of rcu lock to see
whether we need to do slab allocation, it will mitigate memory
pressure from "f2fs_ino_entry" slab cache.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-12 14:21:42 -07:00
Chao Yu
627371ed31 f2fs: extent cache: support unaligned extent
Compressed inode may suffer read performance issue due to it can not
use extent cache, so I propose to add this unaligned extent support
to improve it.

Currently, it only works in readonly format f2fs image.

Unaligned extent: in one compressed cluster, physical block number
will be less than logical block number, so we add an extra physical
block length in extent info in order to indicate such extent status.

The idea is if one whole cluster blocks are contiguous physically,
once its mapping info was readed at first time, we will cache an
unaligned (or aligned) extent info entry in extent cache, it expects
that the mapping info will be hitted when rereading cluster.

Merge policy:
- Aligned extents can be merged.
- Aligned extent and unaligned extent can not be merged.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-05 12:02:51 -07:00
Tiezhu Yang
62d321c3b8 f2fs: Kconfig: clean up config options about compression
In fs/f2fs/Kconfig, F2FS_FS_LZ4HC depends on F2FS_FS_LZ4 and F2FS_FS_LZ4
depends on F2FS_FS_COMPRESSION, so no need to make F2FS_FS_LZ4HC depends
on F2FS_FS_COMPRESSION explicitly, remove the redudant "depends on", do
the similar thing for F2FS_FS_LZORLE.

At the same time, it is better to move F2FS_FS_LZORLE next to F2FS_FS_LZO,
it looks like a little more clear when make menuconfig, the location of
"LZO-RLE compression support" is under "LZO compression support" instead
of "F2FS compression feature".

Without this patch:

F2FS compression feature
  LZO compression support
  LZ4 compression support
    LZ4HC compression support
  ZSTD compression support
  LZO-RLE compression support

With this patch:

F2FS compression feature
  LZO compression support
    LZO-RLE compression support
  LZ4 compression support
    LZ4HC compression support
  ZSTD compression support

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-05 12:02:47 -07:00