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.
>
> 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.
>
> 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
