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| author | Chao Yu <yuchao0@huawei.com> | 2019-07-18 16:39:59 +0800 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2019-08-23 07:57:10 -0700 |
| commit | a8933b6b68f775b5774e7b075447fae13f4d01fe (patch) | |
| tree | a97fca26b81cefef7824a484f0af16393936b569 /fs/f2fs | |
| parent | 1f78adfab379e53b0bd725b869061d9ba8055943 (diff) | |
| download | linux-a8933b6b68f775b5774e7b075447fae13f4d01fe.tar.bz2 | |
f2fs: fix to drop meta/node pages during umount
As reported in bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=204193
A null pointer dereference bug is triggered in f2fs under kernel-5.1.3.
kasan_report.cold+0x5/0x32
f2fs_write_end_io+0x215/0x650
bio_endio+0x26e/0x320
blk_update_request+0x209/0x5d0
blk_mq_end_request+0x2e/0x230
lo_complete_rq+0x12c/0x190
blk_done_softirq+0x14a/0x1a0
__do_softirq+0x119/0x3e5
irq_exit+0x94/0xe0
call_function_single_interrupt+0xf/0x20
During umount, we will access NULL sbi->node_inode pointer in
f2fs_write_end_io():
f2fs_bug_on(sbi, page->mapping == NODE_MAPPING(sbi) &&
page->index != nid_of_node(page));
The reason is if disable_checkpoint mount option is on, meta dirty
pages can remain during umount, and then be flushed by iput() of
meta_inode, however node_inode has been iput()ed before
meta_inode's iput().
Since checkpoint is disabled, all meta/node datas are useless and
should be dropped in next mount, so in umount, let's adjust
drop_inode() to give a hint to iput_final() to drop all those dirty
datas correctly.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs')
| -rw-r--r-- | fs/f2fs/super.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 3ae29d8fb18c..2d2c91c7eadd 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -873,7 +873,21 @@ static struct inode *f2fs_alloc_inode(struct super_block *sb) static int f2fs_drop_inode(struct inode *inode) { + struct f2fs_sb_info *sbi = F2FS_I_SB(inode); int ret; + + /* + * during filesystem shutdown, if checkpoint is disabled, + * drop useless meta/node dirty pages. + */ + if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) { + if (inode->i_ino == F2FS_NODE_INO(sbi) || + inode->i_ino == F2FS_META_INO(sbi)) { + trace_f2fs_drop_inode(inode, 1); + return 1; + } + } + /* * This is to avoid a deadlock condition like below. * writeback_single_inode(inode) |