Messages in this thread | | | Subject | Re: [PATCH v2] f2fs: separate NOCoW and pinfile semantics | From | Chao Yu <> | Date | Wed, 31 Jul 2019 17:55:18 +0800 |
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On 2019/7/31 2:02, Jaegeuk Kim wrote: > On 07/29, Chao Yu wrote: >> On 2019/7/29 13:57, Jaegeuk Kim wrote: >>> On 07/23, Chao Yu wrote: >>>> On 2019/7/23 10:36, Jaegeuk Kim wrote: >>>>> On 07/19, Chao Yu wrote: >>>>>> Pinning a file is heavy, because skipping pinned files make GC >>>>>> running with heavy load or no effect. >>>>> >>>>> Pinned file is a part of NOCOW files, so I don't think we can simply drop it >>>>> for backward compatibility. >>>> >>>> Yes, >>>> >>>> But what I concerned is that pin file is too heavy, so in order to satisfy below >>>> demand, how about introducing pin_file_2 flag to triggering IPU only during >>>> flush/writeback. >>> >>> That can be done by cold files? >> >> Then it may inherit property of cold type file, e.g. a) goes into cold area; b) >> update with very low frequency. >> >> Actually pin_file_2 could be used by db-wal/log file, which are updated >> frequently, and should go to hot/warm area, it does not match above two property. > > How about considering another name like "IPU-only mode"? > > fallocate write Flag GC > Pin_file: preallocate IPU FS_NOCOW_FL Not allowed > IPU_file: Not preallocate IPU N/A Default by temperature
One question, do we need preallocate physical block address for IPU_file as Pin_file? since it can enhance db file's sequential read performance, not sure, db can handle random data in preallocated blocks.
Other behaviors looks good to me. :)
I plan to use last bit in inode.i_inline to store this flag.
> Cold_file: Not preallocate IPU N/A Move in cold area > Hot_file: Not preallocate IPU/OPU N/A Move in hot area
Should hot file be gced to hot area? That would mix new hot data with old 'hot' data which actually become cold.
Thanks,
> >> >> Thank, >> >>> >>>> >>>>> >>>>>> >>>>>> So that this patch propose to separate nocow and pinfile semantics: >>>>>> - NOCoW flag can only be set on regular file. >>>>>> - NOCoW file will only trigger IPU at common writeback/flush. >>>>>> - NOCow file will do OPU during GC. >>>>>> >>>>>> For the demand of 1) avoid fragment of file's physical block and >>>>>> 2) userspace don't care about file's specific physical address, >>>>>> tagging file as NOCoW will be cheaper than pinned one. >>>> >>>> ^^^ >>>> >>>> Thanks, >>>> >>>>>> >>>>>> Signed-off-by: Chao Yu <yuchao0@huawei.com> >>>>>> --- >>>>>> v2: >>>>>> - rebase code to fix compile error. >>>>>> fs/f2fs/data.c | 3 ++- >>>>>> fs/f2fs/f2fs.h | 1 + >>>>>> fs/f2fs/file.c | 22 +++++++++++++++++++--- >>>>>> 3 files changed, 22 insertions(+), 4 deletions(-) >>>>>> >>>>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c >>>>>> index a2a28bb269bf..15fb8954c363 100644 >>>>>> --- a/fs/f2fs/data.c >>>>>> +++ b/fs/f2fs/data.c >>>>>> @@ -1884,7 +1884,8 @@ static inline bool check_inplace_update_policy(struct inode *inode, >>>>>> >>>>>> bool f2fs_should_update_inplace(struct inode *inode, struct f2fs_io_info *fio) >>>>>> { >>>>>> - if (f2fs_is_pinned_file(inode)) >>>>>> + if (f2fs_is_pinned_file(inode) || >>>>>> + F2FS_I(inode)->i_flags & F2FS_NOCOW_FL) >>>>>> return true; >>>>>> >>>>>> /* if this is cold file, we should overwrite to avoid fragmentation */ >>>>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h >>>>>> index 596ab3e1dd7b..f6c5a3d2e659 100644 >>>>>> --- a/fs/f2fs/f2fs.h >>>>>> +++ b/fs/f2fs/f2fs.h >>>>>> @@ -2374,6 +2374,7 @@ static inline void f2fs_change_bit(unsigned int nr, char *addr) >>>>>> #define F2FS_NOATIME_FL 0x00000080 /* do not update atime */ >>>>>> #define F2FS_INDEX_FL 0x00001000 /* hash-indexed directory */ >>>>>> #define F2FS_DIRSYNC_FL 0x00010000 /* dirsync behaviour (directories only) */ >>>>>> +#define F2FS_NOCOW_FL 0x00800000 /* Do not cow file */ >>>>>> #define F2FS_PROJINHERIT_FL 0x20000000 /* Create with parents projid */ >>>>>> >>>>>> /* Flags that should be inherited by new inodes from their parent. */ >>>>>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c >>>>>> index 7ca545874060..ae0fec54cac6 100644 >>>>>> --- a/fs/f2fs/file.c >>>>>> +++ b/fs/f2fs/file.c >>>>>> @@ -1692,6 +1692,7 @@ static const struct { >>>>>> { F2FS_NOATIME_FL, FS_NOATIME_FL }, >>>>>> { F2FS_INDEX_FL, FS_INDEX_FL }, >>>>>> { F2FS_DIRSYNC_FL, FS_DIRSYNC_FL }, >>>>>> + { F2FS_NOCOW_FL, FS_NOCOW_FL }, >>>>>> { F2FS_PROJINHERIT_FL, FS_PROJINHERIT_FL }, >>>>>> }; >>>>>> >>>>>> @@ -1715,7 +1716,8 @@ static const struct { >>>>>> FS_NODUMP_FL | \ >>>>>> FS_NOATIME_FL | \ >>>>>> FS_DIRSYNC_FL | \ >>>>>> - FS_PROJINHERIT_FL) >>>>>> + FS_PROJINHERIT_FL | \ >>>>>> + FS_NOCOW_FL) >>>>>> >>>>>> /* Convert f2fs on-disk i_flags to FS_IOC_{GET,SET}FLAGS flags */ >>>>>> static inline u32 f2fs_iflags_to_fsflags(u32 iflags) >>>>>> @@ -1753,8 +1755,6 @@ static int f2fs_ioc_getflags(struct file *filp, unsigned long arg) >>>>>> fsflags |= FS_ENCRYPT_FL; >>>>>> if (f2fs_has_inline_data(inode) || f2fs_has_inline_dentry(inode)) >>>>>> fsflags |= FS_INLINE_DATA_FL; >>>>>> - if (is_inode_flag_set(inode, FI_PIN_FILE)) >>>>>> - fsflags |= FS_NOCOW_FL; >>>>>> >>>>>> fsflags &= F2FS_GETTABLE_FS_FL; >>>>>> >>>>>> @@ -1794,6 +1794,22 @@ static int f2fs_ioc_setflags(struct file *filp, unsigned long arg) >>>>>> if (ret) >>>>>> goto out; >>>>>> >>>>>> + if ((fsflags ^ old_fsflags) & FS_NOCOW_FL) { >>>>>> + if (!S_ISREG(inode->i_mode)) { >>>>>> + ret = -EINVAL; >>>>>> + goto out; >>>>>> + } >>>>>> + >>>>>> + if (f2fs_should_update_outplace(inode, NULL)) { >>>>>> + ret = -EINVAL; >>>>>> + goto out; >>>>>> + } >>>>>> + >>>>>> + ret = f2fs_convert_inline_inode(inode); >>>>>> + if (ret) >>>>>> + goto out; >>>>>> + } >>>>>> + >>>>>> ret = f2fs_setflags_common(inode, iflags, >>>>>> f2fs_fsflags_to_iflags(F2FS_SETTABLE_FS_FL)); >>>>>> out: >>>>>> -- >>>>>> 2.18.0.rc1 >>>>> . >>>>> >>> . >>> > . >
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