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.
>
>>
>> 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 <yuch...@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
> .
>
