kernel/linux.git/fs/f2fs/extent_cache.c, branch v5.15.208

f2fs: fix KMSAN uninit-value in extent_info usage

2025-08-28T14:24:12+00:00

[ Upstream commit 154467f4ad033473e5c903a03e7b9bca7df9a0fa ] KMSAN reported a use of uninitialized value in `__is_extent_mergeable()` and `__is_back_mergeable()` via the read extent tree path. The root cause is that `get_read_extent_info()` only initializes three fields (`fofs`, `blk`, `len`) of `struct extent_info`, leaving the remaining fields uninitialized. This leads to undefined behavior when those fields are accessed later, especially during extent merging. Fix it by zero-initializing the `extent_info` struct before population. Reported-by: syzbot+b8c1d60e95df65e827d4@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=b8c1d60e95df65e827d4 Fixes: 94afd6d6e525 ("f2fs: extent cache: support unaligned extent") Reviewed-by: Chao Yu Signed-off-by: Abinash Singh Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin

f2fs: fix typos in comments

2024-06-16T11:39:36+00:00

[ Upstream commit 146949defda868378992171b9e42318b06fcd482 ] This patch is to fix typos in f2fs files. Signed-off-by: Jinyoung Choi Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Stable-dep-of: 278a6253a673 ("f2fs: fix to relocate check condition in f2fs_fallocate()") Signed-off-by: Sasha Levin

f2fs: let's avoid panic if extent_tree is not created

2023-01-24T06:22:42+00:00

[ Upstream commit df9d44b645b83fffccfb4e28c1f93376585fdec8 ] This patch avoids the below panic. pc : __lookup_extent_tree+0xd8/0x760 lr : f2fs_do_write_data_page+0x104/0x87c sp : ffffffc010cbb3c0 x29: ffffffc010cbb3e0 x28: 0000000000000000 x27: ffffff8803e7f020 x26: ffffff8803e7ed40 x25: ffffff8803e7f020 x24: ffffffc010cbb460 x23: ffffffc010cbb480 x22: 0000000000000000 x21: 0000000000000000 x20: ffffffff22e90900 x19: 0000000000000000 x18: ffffffc010c5d080 x17: 0000000000000000 x16: 0000000000000020 x15: ffffffdb1acdbb88 x14: ffffff888759e2b0 x13: 0000000000000000 x12: ffffff802da49000 x11: 000000000a001200 x10: ffffff8803e7ed40 x9 : ffffff8023195800 x8 : ffffff802da49078 x7 : 0000000000000001 x6 : 0000000000000000 x5 : 0000000000000006 x4 : ffffffc010cbba28 x3 : 0000000000000000 x2 : ffffffc010cbb480 x1 : 0000000000000000 x0 : ffffff8803e7ed40 Call trace: __lookup_extent_tree+0xd8/0x760 f2fs_do_write_data_page+0x104/0x87c f2fs_write_single_data_page+0x420/0xb60 f2fs_write_cache_pages+0x418/0xb1c __f2fs_write_data_pages+0x428/0x58c f2fs_write_data_pages+0x30/0x40 do_writepages+0x88/0x190 __writeback_single_inode+0x48/0x448 writeback_sb_inodes+0x468/0x9e8 __writeback_inodes_wb+0xb8/0x2a4 wb_writeback+0x33c/0x740 wb_do_writeback+0x2b4/0x400 wb_workfn+0xe4/0x34c process_one_work+0x24c/0x5bc worker_thread+0x3e8/0xa50 kthread+0x150/0x1b4 Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin

f2fs: fix race condition on setting FI_NO_EXTENT flag

2022-10-26T10:35:28+00:00

[ Upstream commit 07725adc55c0a414c10acb5c8c86cea34b95ddef ] The following scenarios exist. process A: process B: ->f2fs_drop_extent_tree ->f2fs_update_extent_cache_range ->f2fs_update_extent_tree_range ->write_lock ->set_inode_flag ->is_inode_flag_set ->__free_extent_tree // Shouldn't // have been // cleaned up // here ->write_lock In this case, the "FI_NO_EXTENT" flag is set between f2fs_update_extent_tree_range and is_inode_flag_set by other process. it leads to clearing the whole exten tree which should not have happened. And we fix it by move the setting it to the range of write_lock. Fixes:5f281fab9b9a3 ("f2fs: disable extent_cache for fcollapse/finsert inodes") Signed-off-by: Zhang Qilong Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin

f2fs: support fault injection for f2fs_kmem_cache_alloc()

2021-08-17T18:59:05+00:00

This patch supports to inject fault into f2fs_kmem_cache_alloc(). Usage: a) echo 32768 > /sys/fs/f2fs//inject_type or b) mount -o fault_type=32768 Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: extent cache: support unaligned extent

2021-08-05T18:26:11+00:00

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 Signed-off-by: Jaegeuk Kim

f2fs: support 64-bits key in f2fs rb-tree node entry

2020-09-10T21:03:30+00:00

then, we can add specified entry into rb-tree with 64-bits segment time as key. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: fix to wait page writeback before update

2020-07-08T04:51:45+00:00

Filesystem including f2fs should support stable page for special device like software raid, however there is one missing path that page could be updated while it is writeback state as below, fix this. - gc_node_segment - f2fs_move_node_page - __write_node_page - set_page_writeback - do_read_inode - f2fs_init_extent_tree - __f2fs_init_extent_tree i_ext->len = 0; Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: introduce f2fs_ macros to wrap f2fs_printk()

2019-07-02T22:40:40+00:00

- Add and use f2fs_ macros - Convert f2fs_msg to f2fs_printk - Remove level from f2fs_printk and embed the level in the format - Coalesce formats and align multi-line arguments - Remove unnecessary duplicate extern f2fs_msg f2fs.h Signed-off-by: Joe Perches Signed-off-by: Chao Yu Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: fix to initialize variable to avoid UBSAN/smatch warning

2019-01-22T23:31:26+00:00

As Dan Carpenter as below: The patch df634f444ee9: "f2fs: use rb_*_cached friends" from Oct 4, 2018, leads to the following static checker warning: fs/f2fs/extent_cache.c:606 f2fs_update_extent_tree_range() error: uninitialized symbol 'leftmost'. And also Eric Biggers, and Kyungtae Kim reported, there is an UBSAN warning described as below: We report a bug in linux-4.20.2: "UBSAN: Undefined behaviour in fs/f2fs/extent_cache.c" kernel config: https://kt0755.github.io/etc/config_v4.20_stable repro: https://kt0755.github.io/etc/repro.4a3e7.c (f2fs is mounted on /mnt/f2fs/) This arose in f2fs_update_extent_tree_range (fs/f2fs/extent_cache.c:605). It seems that, for some reason, its last argument became "24" although that was supposed to be bool type. ========================================= UBSAN: Undefined behaviour in fs/f2fs/extent_cache.c:605:4 load of value 24 is not a valid value for type '_Bool' CPU: 0 PID: 6774 Comm: syz-executor5 Not tainted 4.20.2 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xb1/0x118 lib/dump_stack.c:113 ubsan_epilogue+0x12/0x94 lib/ubsan.c:159 __ubsan_handle_load_invalid_value+0x17a/0x1be lib/ubsan.c:457 f2fs_update_extent_tree_range+0x1d4a/0x1d50 fs/f2fs/extent_cache.c:605 f2fs_update_extent_cache+0x2b6/0x350 fs/f2fs/extent_cache.c:804 f2fs_update_data_blkaddr+0x61/0x70 fs/f2fs/data.c:656 f2fs_outplace_write_data+0x1d6/0x4b0 fs/f2fs/segment.c:3140 f2fs_convert_inline_page+0x86d/0x2060 fs/f2fs/inline.c:163 f2fs_convert_inline_inode+0x6b5/0xad0 fs/f2fs/inline.c:208 f2fs_preallocate_blocks+0x78b/0xb00 fs/f2fs/data.c:982 f2fs_file_write_iter+0x31b/0xf40 fs/f2fs/file.c:3062 call_write_iter include/linux/fs.h:1857 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x538/0x6e0 fs/read_write.c:487 vfs_write+0x1b3/0x520 fs/read_write.c:549 ksys_write+0xde/0x1c0 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x7e/0xc0 fs/read_write.c:607 do_syscall_64+0xbe/0x4f0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4497b9 Code: e8 8c 9f 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 9b 6b fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f1ea15edc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f1ea15ee6cc RCX: 00000000004497b9 RDX: 0000000000001000 RSI: 0000000020000140 RDI: 0000000000000013 RBP: 000000000071bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000bb50 R14: 00000000006f4bf0 R15: 00007f1ea15ee700 ========================================= As I checked, this uninitialized variable won't cause extent cache corruption, but in order to avoid such kind of warning of both UBSAN and smatch, fix to initialize related variable. Reported-by: Dan Carpenter Reported-by: Eric Biggers Reported-by: Kyungtae Kim Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim