On Tue, Jun 30, 2015 at 11:00:13AM +0800, Chao Yu wrote: > Hi Jaegeuk, > > > -----Original Message----- > > From: Jaegeuk Kim [mailto:jaegeuk@xxxxxxxxxx] > > Sent: Tuesday, June 30, 2015 2:39 AM > > To: linux-kernel@xxxxxxxxxxxxxxx; linux-fsdevel@xxxxxxxxxxxxxxx; > > linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > > Cc: Jaegeuk Kim > > Subject: [f2fs-dev] [PATCH 04/12] f2fs: remove wrong f2fs_bug_on when merging extents > > > > In f2fs_update_extent_tree, if there is existing extent, f2fs tries to split > > it with two parts. > > In each trial, __insert_extent_tree checks __is_front/back_mergeable, and then > > if it hits to go, there is f2fs_bug_on(!den), which triggers a kernel panic. > > > > Actually, we don't need to check this. Instead, we can do __try_back_merge only > > when there exists a den pointer. > > > > Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> > > --- > > fs/f2fs/data.c | 8 ++++---- > > 1 file changed, 4 insertions(+), 4 deletions(-) > > > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > > index 9bedfa8..7817167 100644 > > --- a/fs/f2fs/data.c > > +++ b/fs/f2fs/data.c > > @@ -519,19 +519,19 @@ static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi, > > > > if (ei->fofs < en->ei.fofs) { > > if (__is_front_mergeable(ei, &en->ei)) { > > - f2fs_bug_on(sbi, !den); > > I add a BUG_ON here because we assume that in extent cache there is no such > two extents whose mapping address is continuous but without being merged, > since whenever we add a new extent(not splitted one) into cache, we tries to > merge it frontward/backward, then all extent with continuous mapping should be > merged. So when we split one extent to two parts, each part should not be able > to merge with others. Otherwise it should be a bug. Oh, I see. Let me take a look at this one more time. I'm confusing whether this patch was written before fixing block address calculation and then change the order of the patches. Thanks, -- 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
