Messages in this thread | | | Date | Mon, 19 Jun 2023 22:13:21 +0800 | Subject | Re: [PATCH] f2fs: compress: don't force buffered io when in COMPR_MODE_USER mode | From | Chao Yu <> |
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On 2023/6/19 17:31, Yangtao Li wrote: > On 2023/6/19 12:04, Chao Yu wrote: > >> On 2023/6/19 11:11, Yangtao Li wrote: >>> On 2023/6/19 8:54, Chao Yu wrote: >>> >>>> On 2023/6/13 12:14, Yangtao Li wrote: >>>>> >>>>> On 2023/6/12 22:38, Chao Yu wrote: >>>>>> On 2023/6/9 21:15, Yangtao Li wrote: >>>>>>> It is observed that when in user compression mode >>>>>>> (compress_extension=*), >>>>>>> even though the file is not compressed, the file is still forced >>>>>>> to use >>>>>>> buffer io, which makes the AndroBench sequential read and write drop >>>>>>> significantly. In fact, when the file is not compressed, we don't >>>>>>> need >>>>>>> to force it to buffer io. >>>>>>> >>>>>>> | w/o patch | w/ patch | >>>>>>> seq read (MB/s) | 1320.068 | 3696.154 | >>>>>>> seq write (MB/s) | 617.996 | 2978.478 | >>>>>>> >>>>>>> Fixes: 4c8ff7095bef ("f2fs: support data compression") >>>>>>> Signed-off-by: Qi Han <hanqi@vivo.com> >>>>>>> Signed-off-by: Yangtao Li <frank.li@vivo.com> >>>>>>> --- >>>>>>> fs/f2fs/f2fs.h | 14 ++++++++++++++ >>>>>>> fs/f2fs/file.c | 2 +- >>>>>>> 2 files changed, 15 insertions(+), 1 deletion(-) >>>>>>> >>>>>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h >>>>>>> index 1efcfd9e5a99..7f5472525310 100644 >>>>>>> --- a/fs/f2fs/f2fs.h >>>>>>> +++ b/fs/f2fs/f2fs.h >>>>>>> @@ -3168,6 +3168,20 @@ static inline int f2fs_compressed_file(struct >>>>>>> inode *inode) >>>>>>> is_inode_flag_set(inode, FI_COMPRESSED_FILE); >>>>>>> } >>>>>>> +static inline bool f2fs_is_compressed_file(struct inode *inode) >>>>>>> +{ >>>>>>> + int compress_mode = >>>>>>> F2FS_OPTION(F2FS_I_SB(inode)).compress_mode; >>>>>>> + >>>>>>> + if (compress_mode == COMPR_MODE_FS) >>>>>>> + return f2fs_compressed_file(inode); >>>>>>> + else if (atomic_read(&F2FS_I(inode)->i_compr_blocks) || >>>>>> >>>>>> Should check dirty page as well? i_compr_blocks may increase after >>>>>> data writeback. >>>>>> >>>>> IIUC, in COMPR_MODE_USER mode, i_compr_blocks will only be updated >>>>> when >>>>> FI_ENABLE_COMPRESS is enabled. >>>>> >>>>> If FI_ENABLE_COMPRESS is not enabled, i_compr_blocks will never be >>>>> updated after data writeback. >>>>> >>>>> So there is no need to additionally judge whether there is a dirty >>>>> page? >>>> >>>> Oh, user mode, that's correct. >>>> >>>> If we allow dio/aio on compress file, it needs to consider race case in >>>> between aio and ioc_compress_file. >>> >>> >>> The inode_lock is already held in f2fs_file_write_iter and >>> f2fs_ioc_compress_file, I guess this is enough? >>> >>> What else? >> >> aio may complete outside inode lock, so it needs to call inode_dio_wait() >> in f2fs_ioc_compress_file() to avoid the race case? > > > How about adding this below? > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > index f45d05c13ae5..5021d13e788b 100644 > --- a/fs/f2fs/file.c > +++ b/fs/f2fs/file.c > @@ -4146,6 +4146,10 @@ static int f2fs_ioc_compress_file(struct file *filp) > goto out; > } > > + /* avoid race case between aio and ioc_compress_file */ > + if (F2FS_OPTION(sbi).compress_mode == COMPR_MODE_USER)
f2fs_ioc_compress_file() has already checked the mode?
Thanks,
> + inode_dio_wait(inode); > + > ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX); > if (ret) > goto out; > > > Thanks, > > >> >> Thanks, >> >>> >>> >>> 4691 static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct >>> iov_iter *from) >>> 4692 { >>> 4693 struct inode *inode = file_inode(iocb->ki_filp); >>> 4694 const loff_t orig_pos = iocb->ki_pos; >>> 4695 const size_t orig_count = iov_iter_count(from); >>> 4696 loff_t target_size; >>> 4697 bool dio; >>> 4698 bool may_need_sync = true; >>> 4699 int preallocated; >>> 4700 ssize_t ret; >>> 4701 >>> 4702 if (unlikely(f2fs_cp_error(F2FS_I_SB(inode)))) { >>> 4703 ret = -EIO; >>> 4704 goto out; >>> 4705 } >>> 4706 >>> 4707 if (!f2fs_is_compress_backend_ready(inode)) { >>> 4708 ret = -EOPNOTSUPP; >>> 4709 goto out; >>> 4710 } >>> 4711 >>> 4712 if (iocb->ki_flags & IOCB_NOWAIT) { >>> 4713 if (!inode_trylock(inode)) { >>> 4714 ret = -EAGAIN; >>> 4715 goto out; >>> 4716 } >>> 4717 } else { >>> 4718 inode_lock(inode); >>> 4719 } >>> >>> >>> 4115 static int f2fs_ioc_compress_file(struct file *filp) >>> 4116 { >>> 4117 struct inode *inode = file_inode(filp); >>> 4118 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); >>> 4119 pgoff_t page_idx = 0, last_idx; >>> 4120 unsigned int blk_per_seg = sbi->blocks_per_seg; >>> 4121 int cluster_size = F2FS_I(inode)->i_cluster_size; >>> 4122 int count, ret; >>> 4123 >>> 4124 if (!f2fs_sb_has_compression(sbi) || >>> 4125 F2FS_OPTION(sbi).compress_mode != >>> COMPR_MODE_USER) >>> 4126 return -EOPNOTSUPP; >>> 4127 >>> 4128 if (!(filp->f_mode & FMODE_WRITE)) >>> 4129 return -EBADF; >>> 4130 >>> 4131 if (!f2fs_compressed_file(inode)) >>> 4132 return -EINVAL; >>> 4133 >>> 4134 f2fs_balance_fs(sbi, true); >>> 4135 >>> 4136 file_start_write(filp); >>> 4137 inode_lock(inode); >>> >>> >>> Thanks, >>> >>>> >>>> Thanks, >>>> >>>>> >>>>> >>>>> Thanks, >>>>> >>>>>> Thanks, >>>>>> >>>>>>> + is_inode_flag_set(inode, FI_COMPRESS_RELEASED) || >>>>>>> + is_inode_flag_set(inode, FI_ENABLE_COMPRESS)) >>>>>>> + return true; >>>>>>> + >>>>>>> + return false; >>>>>>> +} >>>>>>> + >>>>>>> static inline bool f2fs_need_compress_data(struct inode *inode) >>>>>>> { >>>>>>> int compress_mode = >>>>>>> F2FS_OPTION(F2FS_I_SB(inode)).compress_mode; >>>>>>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c >>>>>>> index 74ecc9e20619..0698129b2165 100644 >>>>>>> --- a/fs/f2fs/file.c >>>>>>> +++ b/fs/f2fs/file.c >>>>>>> @@ -821,7 +821,7 @@ static bool f2fs_force_buffered_io(struct inode >>>>>>> *inode, int rw) >>>>>>> return true; >>>>>>> if (fsverity_active(inode)) >>>>>>> return true; >>>>>>> - if (f2fs_compressed_file(inode)) >>>>>>> + if (f2fs_is_compressed_file(inode)) >>>>>>> return true; >>>>>>> /* disallow direct IO if any of devices has unaligned >>>>>>> blksize */
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