<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/fs/f2fs/node.c, branch v5.14</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>f2fs: drop dirty node pages when cp is in error status</title>
<updated>2021-07-07T05:05:06+00:00</updated>
<author>
<name>Jaegeuk Kim</name>
<email>jaegeuk@kernel.org</email>
</author>
<published>2021-07-07T05:05:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=28607bf3aa6f9762b32dc7f1ed0488823c0651b8'/>
<id>28607bf3aa6f9762b32dc7f1ed0488823c0651b8</id>
<content type='text'>
Otherwise, writeback is going to fall in a loop to flush dirty inode forever
before getting SBI_CLOSING.

Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Otherwise, writeback is going to fall in a loop to flush dirty inode forever
before getting SBI_CLOSING.

Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: compress: add compress_inode to cache compressed blocks</title>
<updated>2021-06-23T08:09:35+00:00</updated>
<author>
<name>Chao Yu</name>
<email>yuchao0@huawei.com</email>
</author>
<published>2021-05-20T11:51:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6ce19aff0b8cd386860855185c6cd79337fc4d2b'/>
<id>6ce19aff0b8cd386860855185c6cd79337fc4d2b</id>
<content type='text'>
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 &lt;yuchao0@huawei.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;yuchao0@huawei.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: restructure f2fs page.private layout</title>
<updated>2021-05-14T18:22:08+00:00</updated>
<author>
<name>Chao Yu</name>
<email>yuchao0@huawei.com</email>
</author>
<published>2021-04-28T09:20:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b763f3bedc2da2edf81bba550430847f561eae0e'/>
<id>b763f3bedc2da2edf81bba550430847f561eae0e</id>
<content type='text'>
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 &lt;willy@infradead.org&gt;
Signed-off-by: Chao Yu &lt;yuchao0@huawei.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;willy@infradead.org&gt;
Signed-off-by: Chao Yu &lt;yuchao0@huawei.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: clean up build warnings</title>
<updated>2021-04-10T17:36:39+00:00</updated>
<author>
<name>Yi Zhuang</name>
<email>zhuangyi1@huawei.com</email>
</author>
<published>2021-04-06T01:47:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5f029c045c948b6cb8ccfda614e73240c4a8363b'/>
<id>5f029c045c948b6cb8ccfda614e73240c4a8363b</id>
<content type='text'>
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 &lt;zhuangyi1@huawei.com&gt;
Signed-off-by: Jia Yang &lt;jiayang5@huawei.com&gt;
Signed-off-by: Jack Qiu &lt;jack.qiu@huawei.com&gt;
Reviewed-by: Chao Yu &lt;yuchao0@huawei.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;zhuangyi1@huawei.com&gt;
Signed-off-by: Jia Yang &lt;jiayang5@huawei.com&gt;
Signed-off-by: Jack Qiu &lt;jack.qiu@huawei.com&gt;
Reviewed-by: Chao Yu &lt;yuchao0@huawei.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: allow to change discard policy based on cached discard cmds</title>
<updated>2021-03-26T17:27:44+00:00</updated>
<author>
<name>Sahitya Tummala</name>
<email>stummala@codeaurora.org</email>
</author>
<published>2021-03-16T09:29:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d6d2b491a82e1e411a6766fbfb87c697d8701554'/>
<id>d6d2b491a82e1e411a6766fbfb87c697d8701554</id>
<content type='text'>
With the default DPOLICY_BG discard thread is ioaware, which prevents
the discard thread from issuing the discard commands. On low RAM setups,
it is observed that these discard commands in the cache are consuming
high memory. This patch aims to relax the memory pressure on the system
due to f2fs pending discard cmds by changing the policy to DPOLICY_FORCE
based on the nm_i-&gt;ram_thresh configured.

Signed-off-by: Sahitya Tummala &lt;stummala@codeaurora.org&gt;
Reviewed-by: Chao Yu &lt;yuchao0@huawei.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
With the default DPOLICY_BG discard thread is ioaware, which prevents
the discard thread from issuing the discard commands. On low RAM setups,
it is observed that these discard commands in the cache are consuming
high memory. This patch aims to relax the memory pressure on the system
due to f2fs pending discard cmds by changing the policy to DPOLICY_FORCE
based on the nm_i-&gt;ram_thresh configured.

Signed-off-by: Sahitya Tummala &lt;stummala@codeaurora.org&gt;
Reviewed-by: Chao Yu &lt;yuchao0@huawei.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: fix to avoid out-of-bounds memory access</title>
<updated>2021-03-26T01:20:51+00:00</updated>
<author>
<name>Chao Yu</name>
<email>yuchao0@huawei.com</email>
</author>
<published>2021-03-22T11:47:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b862676e371715456c9dade7990c8004996d0d9e'/>
<id>b862676e371715456c9dade7990c8004996d0d9e</id>
<content type='text'>
butt3rflyh4ck &lt;butterflyhuangxx@gmail.com&gt; reported a bug found by
syzkaller fuzzer with custom modifications in 5.12.0-rc3+ [1]:

 dump_stack+0xfa/0x151 lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x82/0x32c mm/kasan/report.c:232
 __kasan_report mm/kasan/report.c:399 [inline]
 kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416
 f2fs_test_bit fs/f2fs/f2fs.h:2572 [inline]
 current_nat_addr fs/f2fs/node.h:213 [inline]
 get_next_nat_page fs/f2fs/node.c:123 [inline]
 __flush_nat_entry_set fs/f2fs/node.c:2888 [inline]
 f2fs_flush_nat_entries+0x258e/0x2960 fs/f2fs/node.c:2991
 f2fs_write_checkpoint+0x1372/0x6a70 fs/f2fs/checkpoint.c:1640
 f2fs_issue_checkpoint+0x149/0x410 fs/f2fs/checkpoint.c:1807
 f2fs_sync_fs+0x20f/0x420 fs/f2fs/super.c:1454
 __sync_filesystem fs/sync.c:39 [inline]
 sync_filesystem fs/sync.c:67 [inline]
 sync_filesystem+0x1b5/0x260 fs/sync.c:48
 generic_shutdown_super+0x70/0x370 fs/super.c:448
 kill_block_super+0x97/0xf0 fs/super.c:1394

The root cause is, if nat entry in checkpoint journal area is corrupted,
e.g. nid of journalled nat entry exceeds max nid value, during checkpoint,
once it tries to flush nat journal to NAT area, get_next_nat_page() may
access out-of-bounds memory on nat_bitmap due to it uses wrong nid value
as bitmap offset.

[1] https://lore.kernel.org/lkml/CAFcO6XOMWdr8pObek6eN6-fs58KG9doRFadgJj-FnF-1x43s2g@mail.gmail.com/T/#u

Reported-and-tested-by: butt3rflyh4ck &lt;butterflyhuangxx@gmail.com&gt;
Signed-off-by: Chao Yu &lt;yuchao0@huawei.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
butt3rflyh4ck &lt;butterflyhuangxx@gmail.com&gt; reported a bug found by
syzkaller fuzzer with custom modifications in 5.12.0-rc3+ [1]:

 dump_stack+0xfa/0x151 lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x82/0x32c mm/kasan/report.c:232
 __kasan_report mm/kasan/report.c:399 [inline]
 kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416
 f2fs_test_bit fs/f2fs/f2fs.h:2572 [inline]
 current_nat_addr fs/f2fs/node.h:213 [inline]
 get_next_nat_page fs/f2fs/node.c:123 [inline]
 __flush_nat_entry_set fs/f2fs/node.c:2888 [inline]
 f2fs_flush_nat_entries+0x258e/0x2960 fs/f2fs/node.c:2991
 f2fs_write_checkpoint+0x1372/0x6a70 fs/f2fs/checkpoint.c:1640
 f2fs_issue_checkpoint+0x149/0x410 fs/f2fs/checkpoint.c:1807
 f2fs_sync_fs+0x20f/0x420 fs/f2fs/super.c:1454
 __sync_filesystem fs/sync.c:39 [inline]
 sync_filesystem fs/sync.c:67 [inline]
 sync_filesystem+0x1b5/0x260 fs/sync.c:48
 generic_shutdown_super+0x70/0x370 fs/super.c:448
 kill_block_super+0x97/0xf0 fs/super.c:1394

The root cause is, if nat entry in checkpoint journal area is corrupted,
e.g. nid of journalled nat entry exceeds max nid value, during checkpoint,
once it tries to flush nat journal to NAT area, get_next_nat_page() may
access out-of-bounds memory on nat_bitmap due to it uses wrong nid value
as bitmap offset.

[1] https://lore.kernel.org/lkml/CAFcO6XOMWdr8pObek6eN6-fs58KG9doRFadgJj-FnF-1x43s2g@mail.gmail.com/T/#u

Reported-and-tested-by: butt3rflyh4ck &lt;butterflyhuangxx@gmail.com&gt;
Signed-off-by: Chao Yu &lt;yuchao0@huawei.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: Add bio_max_segs</title>
<updated>2021-02-26T22:49:51+00:00</updated>
<author>
<name>Matthew Wilcox (Oracle)</name>
<email>willy@infradead.org</email>
</author>
<published>2021-01-29T04:38:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5f7136db82996089cdfb2939c7664b29e9da141d'/>
<id>5f7136db82996089cdfb2939c7664b29e9da141d</id>
<content type='text'>
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 &lt;chaitanya.kulkarni@wdc.com&gt;
Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;chaitanya.kulkarni@wdc.com&gt;
Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: deprecate f2fs_trace_io</title>
<updated>2021-01-27T23:20:07+00:00</updated>
<author>
<name>Jaegeuk Kim</name>
<email>jaegeuk@kernel.org</email>
</author>
<published>2021-01-14T21:59:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d5f7bc0064e0541164bd3deeafad16bbb5992433'/>
<id>d5f7bc0064e0541164bd3deeafad16bbb5992433</id>
<content type='text'>
This patch deprecates f2fs_trace_io, since f2fs uses page-&gt;private more broadly,
resulting in more buggy cases.

Acked-by: Chao Yu &lt;yuchao0@huawei.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch deprecates f2fs_trace_io, since f2fs uses page-&gt;private more broadly,
resulting in more buggy cases.

Acked-by: Chao Yu &lt;yuchao0@huawei.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: Replace expression with offsetof()</title>
<updated>2021-01-27T23:20:00+00:00</updated>
<author>
<name>Zheng Yongjun</name>
<email>zhengyongjun3@huawei.com</email>
</author>
<published>2020-12-22T13:34:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=36218b81f094648d929994399eb6eb5c97b991e5'/>
<id>36218b81f094648d929994399eb6eb5c97b991e5</id>
<content type='text'>
Use the existing offsetof() macro instead of duplicating code.

Signed-off-by: Zheng Yongjun &lt;zhengyongjun3@huawei.com&gt;
Reviewed-by: Chao Yu &lt;yuchao0@huawei.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Use the existing offsetof() macro instead of duplicating code.

Signed-off-by: Zheng Yongjun &lt;zhengyongjun3@huawei.com&gt;
Reviewed-by: Chao Yu &lt;yuchao0@huawei.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: fix to account inline xattr correctly during recovery</title>
<updated>2020-12-08T22:25:41+00:00</updated>
<author>
<name>Chao Yu</name>
<email>yuchao0@huawei.com</email>
</author>
<published>2020-12-07T09:54:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=96dd02519580faa731066351f438a2f967d9a0ee'/>
<id>96dd02519580faa731066351f438a2f967d9a0ee</id>
<content type='text'>
During recovery, we may missed to update inline xattr count correctly,
fix it.

Signed-off-by: Chao Yu &lt;yuchao0@huawei.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
During recovery, we may missed to update inline xattr count correctly,
fix it.

Signed-off-by: Chao Yu &lt;yuchao0@huawei.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
