<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/fs/f2fs/inode.c, branch for-next</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>f2fs: introduce device aliasing file</title>
<updated>2024-11-01T01:19:00+00:00</updated>
<author>
<name>Daeho Jeong</name>
<email>daehojeong@google.com</email>
</author>
<published>2024-10-17T17:31:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=128d333f0dff2fbe41c546581c6f151e9d68cd4c'/>
<id>128d333f0dff2fbe41c546581c6f151e9d68cd4c</id>
<content type='text'>
F2FS should understand how the device aliasing file works and support
deleting the file after use. A device aliasing file can be created by
mkfs.f2fs tool and it can map the whole device with an extent, not
using node blocks. The file space should be pinned and normally used for
read-only usages.

Signed-off-by: Daeho Jeong &lt;daehojeong@google.com&gt;
Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
F2FS should understand how the device aliasing file works and support
deleting the file after use. A device aliasing file can be created by
mkfs.f2fs tool and it can map the whole device with an extent, not
using node blocks. The file space should be pinned and normally used for
read-only usages.

Signed-off-by: Daeho Jeong &lt;daehojeong@google.com&gt;
Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: fix f2fs_bug_on when uninstalling filesystem call f2fs_evict_inode.</title>
<updated>2024-10-14T20:04:57+00:00</updated>
<author>
<name>Qi Han</name>
<email>hanqi@vivo.com</email>
</author>
<published>2024-09-18T08:44:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d5c367ef8287fb4d235c46a2f8c8d68715f3a0ca'/>
<id>d5c367ef8287fb4d235c46a2f8c8d68715f3a0ca</id>
<content type='text'>
creating a large files during checkpoint disable until it runs out of
space and then delete it, then remount to enable checkpoint again, and
then unmount the filesystem triggers the f2fs_bug_on as below:

------------[ cut here ]------------
kernel BUG at fs/f2fs/inode.c:896!
CPU: 2 UID: 0 PID: 1286 Comm: umount Not tainted 6.11.0-rc7-dirty #360
Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
RIP: 0010:f2fs_evict_inode+0x58c/0x610
Call Trace:
 __die_body+0x15/0x60
 die+0x33/0x50
 do_trap+0x10a/0x120
 f2fs_evict_inode+0x58c/0x610
 do_error_trap+0x60/0x80
 f2fs_evict_inode+0x58c/0x610
 exc_invalid_op+0x53/0x60
 f2fs_evict_inode+0x58c/0x610
 asm_exc_invalid_op+0x16/0x20
 f2fs_evict_inode+0x58c/0x610
 evict+0x101/0x260
 dispose_list+0x30/0x50
 evict_inodes+0x140/0x190
 generic_shutdown_super+0x2f/0x150
 kill_block_super+0x11/0x40
 kill_f2fs_super+0x7d/0x140
 deactivate_locked_super+0x2a/0x70
 cleanup_mnt+0xb3/0x140
 task_work_run+0x61/0x90

The root cause is: creating large files during disable checkpoint
period results in not enough free segments, so when writing back root
inode will failed in f2fs_enable_checkpoint. When umount the file
system after enabling checkpoint, the root inode is dirty in
f2fs_evict_inode function, which triggers BUG_ON. The steps to
reproduce are as follows:

dd if=/dev/zero of=f2fs.img bs=1M count=55
mount f2fs.img f2fs_dir -o checkpoint=disable:10%
dd if=/dev/zero of=big bs=1M count=50
sync
rm big
mount -o remount,checkpoint=enable f2fs_dir
umount f2fs_dir

Let's redirty inode when there is not free segments during checkpoint
is disable.

Signed-off-by: Qi Han &lt;hanqi@vivo.com&gt;
Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
creating a large files during checkpoint disable until it runs out of
space and then delete it, then remount to enable checkpoint again, and
then unmount the filesystem triggers the f2fs_bug_on as below:

------------[ cut here ]------------
kernel BUG at fs/f2fs/inode.c:896!
CPU: 2 UID: 0 PID: 1286 Comm: umount Not tainted 6.11.0-rc7-dirty #360
Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
RIP: 0010:f2fs_evict_inode+0x58c/0x610
Call Trace:
 __die_body+0x15/0x60
 die+0x33/0x50
 do_trap+0x10a/0x120
 f2fs_evict_inode+0x58c/0x610
 do_error_trap+0x60/0x80
 f2fs_evict_inode+0x58c/0x610
 exc_invalid_op+0x53/0x60
 f2fs_evict_inode+0x58c/0x610
 asm_exc_invalid_op+0x16/0x20
 f2fs_evict_inode+0x58c/0x610
 evict+0x101/0x260
 dispose_list+0x30/0x50
 evict_inodes+0x140/0x190
 generic_shutdown_super+0x2f/0x150
 kill_block_super+0x11/0x40
 kill_f2fs_super+0x7d/0x140
 deactivate_locked_super+0x2a/0x70
 cleanup_mnt+0xb3/0x140
 task_work_run+0x61/0x90

The root cause is: creating large files during disable checkpoint
period results in not enough free segments, so when writing back root
inode will failed in f2fs_enable_checkpoint. When umount the file
system after enabling checkpoint, the root inode is dirty in
f2fs_evict_inode function, which triggers BUG_ON. The steps to
reproduce are as follows:

dd if=/dev/zero of=f2fs.img bs=1M count=55
mount f2fs.img f2fs_dir -o checkpoint=disable:10%
dd if=/dev/zero of=big bs=1M count=50
sync
rm big
mount -o remount,checkpoint=enable f2fs_dir
umount f2fs_dir

Let's redirty inode when there is not free segments during checkpoint
is disable.

Signed-off-by: Qi Han &lt;hanqi@vivo.com&gt;
Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: prevent atomic file from being dirtied before commit</title>
<updated>2024-09-11T03:30:27+00:00</updated>
<author>
<name>Daeho Jeong</name>
<email>daehojeong@google.com</email>
</author>
<published>2024-09-04T15:33:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=fccaa81de87e80b1809906f7e438e5766fbdc172'/>
<id>fccaa81de87e80b1809906f7e438e5766fbdc172</id>
<content type='text'>
Keep atomic file clean while updating and make it dirtied during commit
in order to avoid unnecessary and excessive inode updates in the previous
fix.

Fixes: 4bf78322346f ("f2fs: mark inode dirty for FI_ATOMIC_COMMITTED flag")
Signed-off-by: Daeho Jeong &lt;daehojeong@google.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>
Keep atomic file clean while updating and make it dirtied during commit
in order to avoid unnecessary and excessive inode updates in the previous
fix.

Fixes: 4bf78322346f ("f2fs: mark inode dirty for FI_ATOMIC_COMMITTED flag")
Signed-off-by: Daeho Jeong &lt;daehojeong@google.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: get rid of page-&gt;index</title>
<updated>2024-09-06T23:04:48+00:00</updated>
<author>
<name>Chao Yu</name>
<email>chao@kernel.org</email>
</author>
<published>2024-08-20T14:55:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5697e94daab9e40cbf1fb368781d110f22fb6760'/>
<id>5697e94daab9e40cbf1fb368781d110f22fb6760</id>
<content type='text'>
Convert to use folio, so that we can get rid of 'page-&gt;index' to
prepare for removal of 'index' field in structure page [1].

[1] https://lore.kernel.org/all/Zp8fgUSIBGQ1TN0D@casper.infradead.org/

Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Reviewed-by: Li Zetao &lt;lizetao1@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>
Convert to use folio, so that we can get rid of 'page-&gt;index' to
prepare for removal of 'index' field in structure page [1].

[1] https://lore.kernel.org/all/Zp8fgUSIBGQ1TN0D@casper.infradead.org/

Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Reviewed-by: Li Zetao &lt;lizetao1@huawei.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: get rid of buffer_head use</title>
<updated>2024-08-15T15:26:40+00:00</updated>
<author>
<name>Chao Yu</name>
<email>chao@kernel.org</email>
</author>
<published>2024-06-18T07:26:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5bcde45578624c43eb35bb739b03c50459971865'/>
<id>5bcde45578624c43eb35bb739b03c50459971865</id>
<content type='text'>
Convert to use folio and related functionality.

Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Convert to use folio and related functionality.

Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: clean up F2FS_I()</title>
<updated>2024-07-10T23:13:15+00:00</updated>
<author>
<name>Chao Yu</name>
<email>chao@kernel.org</email>
</author>
<published>2024-06-25T03:16:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7309871c03be22bee843f6961dcce183f04d48a9'/>
<id>7309871c03be22bee843f6961dcce183f04d48a9</id>
<content type='text'>
Use temporary variable instead of F2FS_I() for cleanup.

Signed-off-by: Chao Yu &lt;chao@kernel.org&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 temporary variable instead of F2FS_I() for cleanup.

Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: use meta inode for GC of COW file</title>
<updated>2024-07-10T22:48:20+00:00</updated>
<author>
<name>Sunmin Jeong</name>
<email>s_min.jeong@samsung.com</email>
</author>
<published>2024-07-10T11:51:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f18d0076933689775fe7faeeb10ee93ff01be6ab'/>
<id>f18d0076933689775fe7faeeb10ee93ff01be6ab</id>
<content type='text'>
In case of the COW file, new updates and GC writes are already
separated to page caches of the atomic file and COW file. As some cases
that use the meta inode for GC, there are some race issues between a
foreground thread and GC thread.

To handle them, we need to take care when to invalidate and wait
writeback of GC pages in COW files as the case of using the meta inode.
Also, a pointer from the COW inode to the original inode is required to
check the state of original pages.

For the former, we can solve the problem by using the meta inode for GC
of COW files. Then let's get a page from the original inode in
move_data_block when GCing the COW file to avoid race condition.

Fixes: 3db1de0e582c ("f2fs: change the current atomic write way")
Cc: stable@vger.kernel.org #v5.19+
Reviewed-by: Sungjong Seo &lt;sj1557.seo@samsung.com&gt;
Reviewed-by: Yeongjin Gil &lt;youngjin.gil@samsung.com&gt;
Signed-off-by: Sunmin Jeong &lt;s_min.jeong@samsung.com&gt;
Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In case of the COW file, new updates and GC writes are already
separated to page caches of the atomic file and COW file. As some cases
that use the meta inode for GC, there are some race issues between a
foreground thread and GC thread.

To handle them, we need to take care when to invalidate and wait
writeback of GC pages in COW files as the case of using the meta inode.
Also, a pointer from the COW inode to the original inode is required to
check the state of original pages.

For the former, we can solve the problem by using the meta inode for GC
of COW files. Then let's get a page from the original inode in
move_data_block when GCing the COW file to avoid race condition.

Fixes: 3db1de0e582c ("f2fs: change the current atomic write way")
Cc: stable@vger.kernel.org #v5.19+
Reviewed-by: Sungjong Seo &lt;sj1557.seo@samsung.com&gt;
Reviewed-by: Yeongjin Gil &lt;youngjin.gil@samsung.com&gt;
Signed-off-by: Sunmin Jeong &lt;s_min.jeong@samsung.com&gt;
Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: remove redundant sanity check in sanity_check_inode()</title>
<updated>2024-06-24T17:50:21+00:00</updated>
<author>
<name>Chao Yu</name>
<email>chao@kernel.org</email>
</author>
<published>2024-06-06T09:55:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=388a2a0640e16a8887f0d47dab207f344fbdb913'/>
<id>388a2a0640e16a8887f0d47dab207f344fbdb913</id>
<content type='text'>
Commit f240d3aaf5a1 ("f2fs: do more sanity check on inode") missed
to remove redundant sanity check on flexible_inline_xattr flag, fix
it.

Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit f240d3aaf5a1 ("f2fs: do more sanity check on inode") missed
to remove redundant sanity check on flexible_inline_xattr flag, fix
it.

Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: fix to truncate preallocated blocks in f2fs_file_open()</title>
<updated>2024-06-12T15:46:03+00:00</updated>
<author>
<name>Chao Yu</name>
<email>chao@kernel.org</email>
</author>
<published>2024-05-29T10:01:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=298b1e4182d657c3e388adcc29477904e9600ed5'/>
<id>298b1e4182d657c3e388adcc29477904e9600ed5</id>
<content type='text'>
chenyuwen reports a f2fs bug as below:

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000011
 fscrypt_set_bio_crypt_ctx+0x78/0x1e8
 f2fs_grab_read_bio+0x78/0x208
 f2fs_submit_page_read+0x44/0x154
 f2fs_get_read_data_page+0x288/0x5f4
 f2fs_get_lock_data_page+0x60/0x190
 truncate_partial_data_page+0x108/0x4fc
 f2fs_do_truncate_blocks+0x344/0x5f0
 f2fs_truncate_blocks+0x6c/0x134
 f2fs_truncate+0xd8/0x200
 f2fs_iget+0x20c/0x5ac
 do_garbage_collect+0x5d0/0xf6c
 f2fs_gc+0x22c/0x6a4
 f2fs_disable_checkpoint+0xc8/0x310
 f2fs_fill_super+0x14bc/0x1764
 mount_bdev+0x1b4/0x21c
 f2fs_mount+0x20/0x30
 legacy_get_tree+0x50/0xbc
 vfs_get_tree+0x5c/0x1b0
 do_new_mount+0x298/0x4cc
 path_mount+0x33c/0x5fc
 __arm64_sys_mount+0xcc/0x15c
 invoke_syscall+0x60/0x150
 el0_svc_common+0xb8/0xf8
 do_el0_svc+0x28/0xa0
 el0_svc+0x24/0x84
 el0t_64_sync_handler+0x88/0xec

It is because inode.i_crypt_info is not initialized during below path:
- mount
 - f2fs_fill_super
  - f2fs_disable_checkpoint
   - f2fs_gc
    - f2fs_iget
     - f2fs_truncate

So, let's relocate truncation of preallocated blocks to f2fs_file_open(),
after fscrypt_file_open().

Fixes: d4dd19ec1ea0 ("f2fs: do not expose unwritten blocks to user by DIO")
Reported-by: chenyuwen &lt;yuwen.chen@xjmz.com&gt;
Closes: https://lore.kernel.org/linux-kernel/20240517085327.1188515-1-yuwen.chen@xjmz.com
Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
chenyuwen reports a f2fs bug as below:

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000011
 fscrypt_set_bio_crypt_ctx+0x78/0x1e8
 f2fs_grab_read_bio+0x78/0x208
 f2fs_submit_page_read+0x44/0x154
 f2fs_get_read_data_page+0x288/0x5f4
 f2fs_get_lock_data_page+0x60/0x190
 truncate_partial_data_page+0x108/0x4fc
 f2fs_do_truncate_blocks+0x344/0x5f0
 f2fs_truncate_blocks+0x6c/0x134
 f2fs_truncate+0xd8/0x200
 f2fs_iget+0x20c/0x5ac
 do_garbage_collect+0x5d0/0xf6c
 f2fs_gc+0x22c/0x6a4
 f2fs_disable_checkpoint+0xc8/0x310
 f2fs_fill_super+0x14bc/0x1764
 mount_bdev+0x1b4/0x21c
 f2fs_mount+0x20/0x30
 legacy_get_tree+0x50/0xbc
 vfs_get_tree+0x5c/0x1b0
 do_new_mount+0x298/0x4cc
 path_mount+0x33c/0x5fc
 __arm64_sys_mount+0xcc/0x15c
 invoke_syscall+0x60/0x150
 el0_svc_common+0xb8/0xf8
 do_el0_svc+0x28/0xa0
 el0_svc+0x24/0x84
 el0t_64_sync_handler+0x88/0xec

It is because inode.i_crypt_info is not initialized during below path:
- mount
 - f2fs_fill_super
  - f2fs_disable_checkpoint
   - f2fs_gc
    - f2fs_iget
     - f2fs_truncate

So, let's relocate truncation of preallocated blocks to f2fs_file_open(),
after fscrypt_file_open().

Fixes: d4dd19ec1ea0 ("f2fs: do not expose unwritten blocks to user by DIO")
Reported-by: chenyuwen &lt;yuwen.chen@xjmz.com&gt;
Closes: https://lore.kernel.org/linux-kernel/20240517085327.1188515-1-yuwen.chen@xjmz.com
Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: fix to cover read extent cache access with lock</title>
<updated>2024-06-12T15:46:03+00:00</updated>
<author>
<name>Chao Yu</name>
<email>chao@kernel.org</email>
</author>
<published>2024-05-31T02:00:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d7409b05a64f212735f0d33f5f1602051a886eab'/>
<id>d7409b05a64f212735f0d33f5f1602051a886eab</id>
<content type='text'>
syzbot reports a f2fs bug as below:

BUG: KASAN: slab-use-after-free in sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46
Read of size 4 at addr ffff8880739ab220 by task syz-executor200/5097

CPU: 0 PID: 5097 Comm: syz-executor200 Not tainted 6.9.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 &lt;TASK&gt;
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46
 do_read_inode fs/f2fs/inode.c:509 [inline]
 f2fs_iget+0x33e1/0x46e0 fs/f2fs/inode.c:560
 f2fs_nfs_get_inode+0x74/0x100 fs/f2fs/super.c:3237
 generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1413
 exportfs_decode_fh_raw+0x152/0x5f0 fs/exportfs/expfs.c:444
 exportfs_decode_fh+0x3c/0x80 fs/exportfs/expfs.c:584
 do_handle_to_path fs/fhandle.c:155 [inline]
 handle_to_path fs/fhandle.c:210 [inline]
 do_handle_open+0x495/0x650 fs/fhandle.c:226
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

We missed to cover sanity_check_extent_cache() w/ extent cache lock,
so, below race case may happen, result in use after free issue.

- f2fs_iget
 - do_read_inode
  - f2fs_init_read_extent_tree
  : add largest extent entry in to cache
					- shrink
					 - f2fs_shrink_read_extent_tree
					  - __shrink_extent_tree
					   - __detach_extent_node
					   : drop largest extent entry
  - sanity_check_extent_cache
  : access et-&gt;largest w/o lock

let's refactor sanity_check_extent_cache() to avoid extent cache access
and call it before f2fs_init_read_extent_tree() to fix this issue.

Reported-by: syzbot+74ebe2104433e9dc610d@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-f2fs-devel/00000000000009beea061740a531@google.com
Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
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<pre>
syzbot reports a f2fs bug as below:

BUG: KASAN: slab-use-after-free in sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46
Read of size 4 at addr ffff8880739ab220 by task syz-executor200/5097

CPU: 0 PID: 5097 Comm: syz-executor200 Not tainted 6.9.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 &lt;TASK&gt;
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46
 do_read_inode fs/f2fs/inode.c:509 [inline]
 f2fs_iget+0x33e1/0x46e0 fs/f2fs/inode.c:560
 f2fs_nfs_get_inode+0x74/0x100 fs/f2fs/super.c:3237
 generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1413
 exportfs_decode_fh_raw+0x152/0x5f0 fs/exportfs/expfs.c:444
 exportfs_decode_fh+0x3c/0x80 fs/exportfs/expfs.c:584
 do_handle_to_path fs/fhandle.c:155 [inline]
 handle_to_path fs/fhandle.c:210 [inline]
 do_handle_open+0x495/0x650 fs/fhandle.c:226
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

We missed to cover sanity_check_extent_cache() w/ extent cache lock,
so, below race case may happen, result in use after free issue.

- f2fs_iget
 - do_read_inode
  - f2fs_init_read_extent_tree
  : add largest extent entry in to cache
					- shrink
					 - f2fs_shrink_read_extent_tree
					  - __shrink_extent_tree
					   - __detach_extent_node
					   : drop largest extent entry
  - sanity_check_extent_cache
  : access et-&gt;largest w/o lock

let's refactor sanity_check_extent_cache() to avoid extent cache access
and call it before f2fs_init_read_extent_tree() to fix this issue.

Reported-by: syzbot+74ebe2104433e9dc610d@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-f2fs-devel/00000000000009beea061740a531@google.com
Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
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