Messages in this thread | | | Subject | Re: [PATCH] f2fs: protect free nid operation with cp_rwsem | From | Chao Yu <> | Date | Mon, 20 Mar 2017 19:06:02 +0800 |
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Hi Jaegeuk,
On 2017/3/20 6:44, Jaegeuk Kim wrote: > Hi Chao, > > On 03/17, Chao Yu wrote: >> - f2fs_balance_fs_bg >> - build_free_ni >> - __build_free_nids >> - scan_nat_page >> - add_free_nid >> - f2fs_create >> - f2fs_new_inode >> - alloc_nid >> - remove_free_nid >> >> This patch uses cp_rwsem to protect free nid allocation/initialization >> to avoid reusing allocated nid in above scenario. > > It looks like description doesn't match to your change below?
It looks like the problem will not happen because on_build_free_nids will stop alloc_nid stealing one allocated nid while building free nids. Please ignore this patch, sorry.
I found another potential case, could you please check that one?
Thanks,
> > Thanks, > >> >> Signed-off-by: Chao Yu <yuchao0@huawei.com> >> --- >> fs/f2fs/inode.c | 2 ++ >> fs/f2fs/segment.c | 5 ++++- >> 2 files changed, 6 insertions(+), 1 deletion(-) >> >> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c >> index 2520fa72b23f..f941410f994a 100644 >> --- a/fs/f2fs/inode.c >> +++ b/fs/f2fs/inode.c >> @@ -423,7 +423,9 @@ void f2fs_evict_inode(struct inode *inode) >> add_ino_entry(sbi, inode->i_ino, UPDATE_INO); >> } >> if (is_inode_flag_set(inode, FI_FREE_NID)) { >> + f2fs_lock_op(sbi); >> alloc_nid_failed(sbi, inode->i_ino); >> + f2fs_unlock_op(sbi); >> clear_inode_flag(inode, FI_FREE_NID); >> } >> f2fs_bug_on(sbi, err && >> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c >> index 0bf024f62330..f85e1f443c99 100644 >> --- a/fs/f2fs/segment.c >> +++ b/fs/f2fs/segment.c >> @@ -426,8 +426,11 @@ void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi) >> >> if (!available_free_memory(sbi, FREE_NIDS)) >> try_to_free_nids(sbi, MAX_FREE_NIDS); >> - else >> + else { >> + f2fs_lock_op(sbi); >> build_free_nids(sbi, false, false); >> + f2fs_unlock_op(sbi); >> + } >> >> if (!is_idle(sbi)) >> return; >> -- >> 2.8.2.295.g3f1c1d0 > > . >
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