Hi Jaegeuk, > -----Original Message----- > From: Jaegeuk Kim [mailto:jaegeuk@xxxxxxxxxx] > Sent: Tuesday, July 08, 2014 2:37 PM > To: Chao Yu > Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-fsdevel@xxxxxxxxxxxxxxx; > linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > Subject: Re: [f2fs-dev] [PATCH] f2fs: do checkpoint for the renamed inode > > On Mon, Jul 07, 2014 at 11:17:35AM +0800, Chao Yu wrote: > > Hi Jaegeuk, > > > > > -----Original Message----- > > > From: Jaegeuk Kim [mailto:jaegeuk@xxxxxxxxxx] > > > Sent: Wednesday, July 02, 2014 6:35 PM > > > To: linux-kernel@xxxxxxxxxxxxxxx; linux-fsdevel@xxxxxxxxxxxxxxx; > > > linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > > > Cc: Jaegeuk Kim > > > Subject: [f2fs-dev] [PATCH] f2fs: do checkpoint for the renamed inode > > > > > > If an inode is renamed, it should be registered as file_lost_pino to conduct > > > checkpoint at f2fs_sync_file. > > > Otherwise, the inode cannot be recovered due to no dent_mark in the following > > > scenario. > > > > > > Note that, this scenario is from xfstests/322. > > > > > > 1. create "a" > > > 2. fsync "a" > > > 3. rename "a" to "b" > > > 4. fsync "b" > > > 5. Sudden power-cut > > > > > > After recovery is done, "b" should be seen. > > > However, the result shows "a", since the recovery procedure does not enter > > > recover_dentry due to no dent_mark. > > > > As we know CP is expensive, how about modifying checkpointed value directly > > in nat cache at step #3? So "b" could be fsynced with dent_mark at step #4. > > Yes, I also thought about that. > But, when handling the nat cache, one of my concerns was the lock granularity. > Basically each nat cache entry should be covered by its node page lock, so it > is a little bit complicate to do something easily in f2fs_rename. > > So, this patch was to fix the bug with a naive approach. > And we can write additional patch to enhance this too. Thanks for your explanation! :) Regards, Yu > > Thanks, > > > > > > > > > The reason is like below. > > > - The nid of "a" is checkpointed during #2, f2fs_sync_file. > > > - The inode page for "b" produced by #3 is written without dent_mark by > > > sync_node_pages. > > > > > > So, this patch fixes this bug by assinging file_lost_pino to the "a"'s inode. > > > If the pino is lost, f2fs_sync_file conducts checkpoint, and then recovers > > > the latest pino and its dentry information for further recovery. > > > > > > Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> > > > --- > > > fs/f2fs/namei.c | 10 ++++------ > > > 1 file changed, 4 insertions(+), 6 deletions(-) > > > > > > diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c > > > index 96f1dd1..1b3cae0 100644 > > > --- a/fs/f2fs/namei.c > > > +++ b/fs/f2fs/namei.c > > > @@ -411,9 +411,6 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry, > > > } > > > > > > f2fs_set_link(new_dir, new_entry, new_page, old_inode); > > > - down_write(&F2FS_I(old_inode)->i_sem); > > > - F2FS_I(old_inode)->i_pino = new_dir->i_ino; > > > - up_write(&F2FS_I(old_inode)->i_sem); > > > > > > new_inode->i_ctime = CURRENT_TIME; > > > down_write(&F2FS_I(new_inode)->i_sem); > > > @@ -446,6 +443,10 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry, > > > } > > > } > > > > > > + down_write(&F2FS_I(old_inode)->i_sem); > > > + file_lost_pino(old_inode); > > > + up_write(&F2FS_I(old_inode)->i_sem); > > > + > > > old_inode->i_ctime = CURRENT_TIME; > > > mark_inode_dirty(old_inode); > > > > > > @@ -455,9 +456,6 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry, > > > if (old_dir != new_dir) { > > > f2fs_set_link(old_inode, old_dir_entry, > > > old_dir_page, new_dir); > > > - down_write(&F2FS_I(old_inode)->i_sem); > > > - F2FS_I(old_inode)->i_pino = new_dir->i_ino; > > > - up_write(&F2FS_I(old_inode)->i_sem); > > > update_inode_page(old_inode); > > > } else { > > > kunmap(old_dir_page); > > > -- > > > 1.8.5.2 (Apple Git-48) > > > > > > > > > ------------------------------------------------------------------------------ > > > Open source business process management suite built on Java and Eclipse > > > Turn processes into business applications with Bonita BPM Community Edition > > > Quickly connect people, data, and systems into organized workflows > > > Winner of BOSSIE, CODIE, OW2 and Gartner awards > > > http://p.sf.net/sfu/Bonitasoft > > > _______________________________________________ > > > Linux-f2fs-devel mailing list > > > Linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel > > -- > Jaegeuk Kim -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
