On Fri, Sep 21, 2018 at 09:12:22PM +0800, Chao Yu wrote:
> From: Chao Yu <yuch...@huawei.com>
>
> Normally, DIO uses in-pllace-update, but in LFS mode, f2fs doesn't
> allow triggering any in-place-update writes, so we fallback direct
> write to buffered write, result in bad performance of large size
> write.
>
> This patch adds to support triggering out-place-update for direct IO
> to enhance its performance.
>
> Note that it needs to exclude direct read IO during direct write,
> since new data writing to new block address will no be valid until
> write finished.
>
> storage: zram
>
> time xfs_io -f -d /mnt/f2fs/file -c "pwrite 0 1073741824" -c "fsync"
>
> Before:
> real 0m13.061s
> user 0m0.327s
> sys 0m12.486s
>
> After:
> real 0m6.448s
> user 0m0.228s
> sys 0m6.212s
>
> Signed-off-by: Chao Yu <yuch...@huawei.com>
> ---
> v4:
> - correct parameter in f2fs_sb_has_blkzoned()
> fs/f2fs/data.c | 44 +++++++++++++++++++++++++++++++++++---------
> fs/f2fs/f2fs.h | 45 +++++++++++++++++++++++++++++++++++++++++----
> fs/f2fs/file.c | 3 ++-
> 3 files changed, 78 insertions(+), 14 deletions(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index b96f8588d565..38d5baa1c35d 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -894,7 +894,7 @@ static int __allocate_data_block(struct dnode_of_data
> *dn, int seg_type)
>
> dn->data_blkaddr = datablock_addr(dn->inode,
> dn->node_page, dn->ofs_in_node);
> - if (dn->data_blkaddr == NEW_ADDR)
> + if (dn->data_blkaddr != NULL_ADDR)
> goto alloc;
>
> if (unlikely((err = inc_valid_block_count(sbi, dn->inode, &count))))
> @@ -950,7 +950,7 @@ int f2fs_preallocate_blocks(struct kiocb *iocb, struct
> iov_iter *from)
>
> if (direct_io) {
> map.m_seg_type = f2fs_rw_hint_to_seg_type(iocb->ki_hint);
> - flag = f2fs_force_buffered_io(inode, WRITE) ?
> + flag = f2fs_force_buffered_io(inode, iocb, from) ?
> F2FS_GET_BLOCK_PRE_AIO :
> F2FS_GET_BLOCK_PRE_DIO;
> goto map_blocks;
> @@ -1069,7 +1069,15 @@ int f2fs_map_blocks(struct inode *inode, struct
> f2fs_map_blocks *map,
> goto sync_out;
> }
>
> - if (!is_valid_data_blkaddr(sbi, blkaddr)) {
> + if (is_valid_data_blkaddr(sbi, blkaddr)) {
> + /* use out-place-update for driect IO under LFS mode */
> + if (test_opt(sbi, LFS) && create &&
> + flag == F2FS_GET_BLOCK_DEFAULT) {
One of the recent patches from Jaegeuk, 0a4daae5ffea ("f2fs: update i_size
after DIO
completion") added new flag for DIO - F2FS_GET_BLOCK_DIO. I think this patch
needs to be
updated accordingly.
> + err = __allocate_data_block(&dn, map->m_seg_type);
> + if (!err)
> + set_inode_flag(inode, FI_APPEND_WRITE);
> + }
> + } else {
> if (create) {
> if (unlikely(f2fs_cp_error(sbi))) {
> err = -EIO;
> @@ -2493,36 +2501,53 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb,
> struct iov_iter *iter)
> struct address_space *mapping = iocb->ki_filp->f_mapping;
> struct inode *inode = mapping->host;
> struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> + struct f2fs_inode_info *fi = F2FS_I(inode);
> size_t count = iov_iter_count(iter);
> loff_t offset = iocb->ki_pos;
> int rw = iov_iter_rw(iter);
> int err;
> enum rw_hint hint = iocb->ki_hint;
> int whint_mode = F2FS_OPTION(sbi).whint_mode;
> + bool do_opu;
>
> err = check_direct_IO(inode, iter, offset);
> if (err)
> return err < 0 ? err : 0;
>
> - if (f2fs_force_buffered_io(inode, rw))
> + if (f2fs_force_buffered_io(inode, iocb, iter))
> return 0;
>
> + do_opu = allow_outplace_dio(inode, iocb, iter);
> +
> trace_f2fs_direct_IO_enter(inode, offset, count, rw);
>
> if (rw == WRITE && whint_mode == WHINT_MODE_OFF)
> iocb->ki_hint = WRITE_LIFE_NOT_SET;
>
> - if (!down_read_trylock(&F2FS_I(inode)->i_gc_rwsem[rw])) {
> - if (iocb->ki_flags & IOCB_NOWAIT) {
> + if (iocb->ki_flags & IOCB_NOWAIT) {
> + if (!down_read_trylock(&fi->i_gc_rwsem[rw])) {
> + iocb->ki_hint = hint;
> + err = -EAGAIN;
> + goto out;
> + }
> + if (do_opu && !down_read_trylock(&fi->i_gc_rwsem[READ])) {
> + up_read(&fi->i_gc_rwsem[rw]);
> iocb->ki_hint = hint;
> err = -EAGAIN;
> goto out;
> }
> - down_read(&F2FS_I(inode)->i_gc_rwsem[rw]);
> + } else {
> + down_read(&fi->i_gc_rwsem[rw]);
> + if (do_opu)
> + down_read(&fi->i_gc_rwsem[READ]);
> }
>
> err = blockdev_direct_IO(iocb, inode, iter, get_data_block_dio);
> - up_read(&F2FS_I(inode)->i_gc_rwsem[rw]);
> +
> + if (do_opu)
> + up_read(&fi->i_gc_rwsem[READ]);
> +
> + up_read(&fi->i_gc_rwsem[rw]);
>
> if (rw == WRITE) {
> if (whint_mode == WHINT_MODE_OFF)
> @@ -2530,7 +2555,8 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb,
> struct iov_iter *iter)
> if (err > 0) {
> f2fs_update_iostat(F2FS_I_SB(inode), APP_DIRECT_IO,
> err);
> - set_inode_flag(inode, FI_UPDATE_WRITE);
> + if (!do_opu)
> + set_inode_flag(inode, FI_UPDATE_WRITE);
> } else if (err < 0) {
> f2fs_write_failed(mapping, offset + count);
> }
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 894a2503e722..72d46860cee3 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -8,6 +8,7 @@
> #ifndef _LINUX_F2FS_H
> #define _LINUX_F2FS_H
>
> +#include <linux/uio.h>
> #include <linux/types.h>
> #include <linux/page-flags.h>
> #include <linux/buffer_head.h>
> @@ -3486,11 +3487,47 @@ static inline bool f2fs_may_encrypt(struct inode
> *inode)
> #endif
> }
>
> -static inline bool f2fs_force_buffered_io(struct inode *inode, int rw)
> +static inline int block_unaligned_IO(struct inode *inode,
> + struct kiocb *iocb, struct iov_iter *iter)
> {
> - return (f2fs_post_read_required(inode) ||
> - (rw == WRITE && test_opt(F2FS_I_SB(inode), LFS)) ||
> - F2FS_I_SB(inode)->s_ndevs);
> + unsigned int i_blkbits = READ_ONCE(inode->i_blkbits);
> + unsigned int blocksize_mask = (1 << i_blkbits) - 1;
> + loff_t offset = iocb->ki_pos;
> + unsigned long align = offset | iov_iter_alignment(iter);
> +
> + return align & blocksize_mask;
> +}
> +
> +static inline int allow_outplace_dio(struct inode *inode,
> + struct kiocb *iocb, struct iov_iter *iter)
> +{
> + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> + int rw = iov_iter_rw(iter);
> +
> + return (test_opt(sbi, LFS) && (rw == WRITE) &&
> + !block_unaligned_IO(inode, iocb, iter));
> +}
> +
> +static inline bool f2fs_force_buffered_io(struct inode *inode,
> + struct kiocb *iocb, struct iov_iter *iter)
> +{
> + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> + int rw = iov_iter_rw(iter);
> +
> + if (f2fs_post_read_required(inode))
> + return true;
> + if (sbi->s_ndevs)
> + return true;
> + /*
> + * for blkzoned device, fallback direct IO to buffered IO, so
> + * all IOs can be serialized by log-structured write.
> + */
> + if (f2fs_sb_has_blkzoned(sbi->sb))
> + return true;
> + if (test_opt(sbi, LFS) && (rw == WRITE) &&
> + block_unaligned_IO(inode, iocb, iter))
> + return true;
> + return false;
> }
>
> #ifdef CONFIG_F2FS_FAULT_INJECTION
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index a75f3e145bf1..a388866e71ee 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -3019,7 +3019,8 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb,
> struct iov_iter *from)
> if (!f2fs_overwrite_io(inode, iocb->ki_pos,
> iov_iter_count(from)) ||
> f2fs_has_inline_data(inode) ||
> - f2fs_force_buffered_io(inode, WRITE)) {
> + f2fs_force_buffered_io(inode,
> + iocb, from)) {
> clear_inode_flag(inode,
> FI_NO_PREALLOC);
> inode_unlock(inode);
> --
> 2.18.0
>
>
>
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> Linux-f2fs-devel@lists.sourceforge.net
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--
--
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