Hi Jaegeuk, > -----Original Message----- > From: Jaegeuk Kim [mailto:jaegeuk@xxxxxxxxxx] > Sent: Friday, August 22, 2014 12:45 AM > To: Chao Yu > Cc: linux-fsdevel@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > Subject: Re: [f2fs-dev] [PATCH 3/4] f2fs: avoid double lock in truncate_blocks > > On Wed, Aug 20, 2014 at 10:07:04AM +0800, Chao Yu wrote: > > > -----Original Message----- > > > From: Jaegeuk Kim [mailto:jaegeuk@xxxxxxxxxx] > > > Sent: Wednesday, August 20, 2014 12:58 AM > > > To: Chao Yu > > > Cc: linux-fsdevel@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > > > linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > > > Subject: Re: [f2fs-dev] [PATCH 3/4] f2fs: avoid double lock in truncate_blocks > > > > > > On Tue, Aug 19, 2014 at 04:04:11PM +0800, Chao Yu wrote: > > > > Hi Jaegeuk, > > > > > > > > > -----Original Message----- > > > > > From: Jaegeuk Kim [mailto:jaegeuk@xxxxxxxxxx] > > > > > Sent: Saturday, August 16, 2014 6:04 AM > > > > > To: linux-kernel@xxxxxxxxxxxxxxx; linux-fsdevel@xxxxxxxxxxxxxxx; > > > > > linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > > > > > Cc: Jaegeuk Kim > > > > > Subject: [f2fs-dev] [PATCH 3/4] f2fs: avoid double lock in truncate_blocks > > > > > > > > > > The init_inode_metadata calls truncate_blocks when error is occurred. > > > > > The callers holds f2fs_lock_op, so we should not call it again in > > > > > truncate_blocks. > > > > > > > > Nice catch! Your solution is a good way to fix this issue. > > > > > > > > Previously, in create inode path, I found there are some redundant codes between > > > > init_inode_metadata and evict_inode, including: > > > > truncate_inode_pages(&inode->i_data, 0); > > > > truncate_blocks(inode, 0); > > > > remove_dirty_dir_inode(inode); > > > > remove_inode_page(inode); > > > > > > > > So I think there is another way to fix this issue by removing error path handling > > > > codes in init_inode_metadata, not making the inode bad to left garbage clean work in > > > > evict_inode. In this way we can avoid adding additional argument for all different > > > > callers. > > > > > > Well, possible. > > > But we need to take a closer look at the race condition on the inode cache. > > > What can happen if this bad inode is reassigned to the other thread? > > > > I don't get it. As I know, in evict(), we call ->evict_inode before > > remove_inode_hash(), so before all clean work was done we will not reassign > > this hashed uncleaned inode to other thread. > > > > Am I missing anything? > > What I meant was it may happen between init_inode_metadata and iput. Actually, can happen between unlock_new_inode and iput in error path of create/symlink/mkdir/mknod/tmpfile. Scenario is like this: ->f2fs_mkdir ->f2fs_add_link ->__f2fs_add_link ->init_inode_metadata failed here ->gc_thread_func ->f2fs_gc ->do_garbage_collect ->gc_data_segment ->f2fs_iget ->iget_locked ->wait_on_inode ->unlock_new_inode ->move_data_page ->make_bad_inode ->iput No problem now, but I'd like to remove unlock_new_inode from error path of inode creating procedure as we'd better wakeup waiter in end of ->iput instead of wakeup waiter in unlock_new_inode before invoking make_bad_inod. How do you think? Anyway, drop this proposal if you do not like it, although I think it will be ok theoretically after we fix above issue. Thanks, Yu > > Thanks, > > > > > Regards, > > Yu > > > > > > > > > > > > > How do you think? > > > > > > > > Thanks, > > > > Yu > > > > > > > > > > > > > > Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> > > > > > --- > > > > > fs/f2fs/data.c | 2 +- > > > > > fs/f2fs/dir.c | 2 +- > > > > > fs/f2fs/f2fs.h | 2 +- > > > > > fs/f2fs/file.c | 13 ++++++++----- > > > > > fs/f2fs/inline.c | 2 +- > > > > > 5 files changed, 12 insertions(+), 9 deletions(-) > > > > > > > > > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > > > > > index 68834e2..14cc3e8 100644 > > > > > --- a/fs/f2fs/data.c > > > > > +++ b/fs/f2fs/data.c > > > > > @@ -935,7 +935,7 @@ static void f2fs_write_failed(struct address_space *mapping, loff_t > > > to) > > > > > > > > > > if (to > inode->i_size) { > > > > > truncate_pagecache(inode, inode->i_size); > > > > > - truncate_blocks(inode, inode->i_size); > > > > > + truncate_blocks(inode, inode->i_size, true); > > > > > } > > > > > } > > > > > > > > > > diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c > > > > > index a69bbfa..155fb05 100644 > > > > > --- a/fs/f2fs/dir.c > > > > > +++ b/fs/f2fs/dir.c > > > > > @@ -391,7 +391,7 @@ put_error: > > > > > error: > > > > > /* once the failed inode becomes a bad inode, i_mode is S_IFREG */ > > > > > truncate_inode_pages(&inode->i_data, 0); > > > > > - truncate_blocks(inode, 0); > > > > > + truncate_blocks(inode, 0, false); > > > > > remove_dirty_dir_inode(inode); > > > > > remove_inode_page(inode); > > > > > return ERR_PTR(err); > > > > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > > > > > index 2723b2d..7f976c1 100644 > > > > > --- a/fs/f2fs/f2fs.h > > > > > +++ b/fs/f2fs/f2fs.h > > > > > @@ -1122,7 +1122,7 @@ static inline void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi) > > > > > */ > > > > > int f2fs_sync_file(struct file *, loff_t, loff_t, int); > > > > > void truncate_data_blocks(struct dnode_of_data *); > > > > > -int truncate_blocks(struct inode *, u64); > > > > > +int truncate_blocks(struct inode *, u64, bool); > > > > > void f2fs_truncate(struct inode *); > > > > > int f2fs_getattr(struct vfsmount *, struct dentry *, struct kstat *); > > > > > int f2fs_setattr(struct dentry *, struct iattr *); > > > > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > > > > > index ecbdf6a..a8e97f8 100644 > > > > > --- a/fs/f2fs/file.c > > > > > +++ b/fs/f2fs/file.c > > > > > @@ -422,7 +422,7 @@ out: > > > > > f2fs_put_page(page, 1); > > > > > } > > > > > > > > > > -int truncate_blocks(struct inode *inode, u64 from) > > > > > +int truncate_blocks(struct inode *inode, u64 from, bool lock) > > > > > { > > > > > struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); > > > > > unsigned int blocksize = inode->i_sb->s_blocksize; > > > > > @@ -438,14 +438,16 @@ int truncate_blocks(struct inode *inode, u64 from) > > > > > free_from = (pgoff_t) > > > > > ((from + blocksize - 1) >> (sbi->log_blocksize)); > > > > > > > > > > - f2fs_lock_op(sbi); > > > > > + if (lock) > > > > > + f2fs_lock_op(sbi); > > > > > > > > > > set_new_dnode(&dn, inode, NULL, NULL, 0); > > > > > err = get_dnode_of_data(&dn, free_from, LOOKUP_NODE); > > > > > if (err) { > > > > > if (err == -ENOENT) > > > > > goto free_next; > > > > > - f2fs_unlock_op(sbi); > > > > > + if (lock) > > > > > + f2fs_unlock_op(sbi); > > > > > trace_f2fs_truncate_blocks_exit(inode, err); > > > > > return err; > > > > > } > > > > > @@ -463,7 +465,8 @@ int truncate_blocks(struct inode *inode, u64 from) > > > > > f2fs_put_dnode(&dn); > > > > > free_next: > > > > > err = truncate_inode_blocks(inode, free_from); > > > > > - f2fs_unlock_op(sbi); > > > > > + if (lock) > > > > > + f2fs_unlock_op(sbi); > > > > > done: > > > > > /* lastly zero out the first data page */ > > > > > truncate_partial_data_page(inode, from); > > > > > @@ -480,7 +483,7 @@ void f2fs_truncate(struct inode *inode) > > > > > > > > > > trace_f2fs_truncate(inode); > > > > > > > > > > - if (!truncate_blocks(inode, i_size_read(inode))) { > > > > > + if (!truncate_blocks(inode, i_size_read(inode), true)) { > > > > > inode->i_mtime = inode->i_ctime = CURRENT_TIME; > > > > > mark_inode_dirty(inode); > > > > > } > > > > > diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c > > > > > index 520758b..4d1f39f 100644 > > > > > --- a/fs/f2fs/inline.c > > > > > +++ b/fs/f2fs/inline.c > > > > > @@ -247,7 +247,7 @@ process_inline: > > > > > update_inode(inode, ipage); > > > > > f2fs_put_page(ipage, 1); > > > > > } else if (ri && (ri->i_inline & F2FS_INLINE_DATA)) { > > > > > - truncate_blocks(inode, 0); > > > > > + truncate_blocks(inode, 0, false); > > > > > set_inode_flag(F2FS_I(inode), FI_INLINE_DATA); > > > > > goto process_inline; > > > > > } > > > > > -- > > > > > 1.8.5.2 (Apple Git-48) > > > > > > > > > > > > > > > ------------------------------------------------------------------------------ > > > > > _______________________________________________ > > > > > Linux-f2fs-devel mailing list > > > > > Linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > > > > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel > > > > > > > > > > > > ------------------------------------------------------------------------------ > > > > _______________________________________________ > > > > Linux-f2fs-devel mailing list > > > > Linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > > > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel -- 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
