From b91050a80cec3daf5a21f78274330df64a4936a3 Mon Sep 17 00:00:00 2001 From: Hyunchul Lee Date: Thu, 8 Mar 2018 19:34:38 +0900 Subject: [PATCH] f2fs: add nowait aio support This patch adds nowait aio support[1]. Return EAGAIN if any of the following checks fail for direct I/O: - i_rwsem is not lockable - Blocks are not allocated at the write location And xfstests generic/471 is passed. [1]: 6be96d "Introduce RWF_NOWAIT and FMODE_AIO_NOWAIT" Signed-off-by: Hyunchul Lee Reviewed-by: Goldwyn Rodrigues Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/data.c | 47 +++++++++++++++++++++++++++++++++++++---------- fs/f2fs/f2fs.h | 8 ++++++++ fs/f2fs/file.c | 35 +++++++++++++++++++++++++++++------ 3 files changed, 74 insertions(+), 16 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 3d6ae31..f6cf99a 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -839,13 +839,6 @@ alloc: return 0; } -static inline bool __force_buffered_io(struct inode *inode, int rw) -{ - return (f2fs_encrypted_file(inode) || - (rw == WRITE && test_opt(F2FS_I_SB(inode), LFS)) || - F2FS_I_SB(inode)->s_ndevs); -} - int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from) { struct inode *inode = file_inode(iocb->ki_filp); @@ -877,7 +870,7 @@ int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from) if (direct_io) { map.m_seg_type = rw_hint_to_seg_type(iocb->ki_hint); - flag = __force_buffered_io(inode, WRITE) ? + flag = f2fs_force_buffered_io(inode, WRITE) ? F2FS_GET_BLOCK_PRE_AIO : F2FS_GET_BLOCK_PRE_DIO; goto map_blocks; @@ -1121,6 +1114,31 @@ out: return err; } +bool f2fs_overwrite_io(struct inode *inode, loff_t pos, size_t len) +{ + struct f2fs_map_blocks map; + block_t last_lblk; + int err; + + if (pos + len > i_size_read(inode)) + return false; + + map.m_lblk = F2FS_BYTES_TO_BLK(pos); + map.m_next_pgofs = NULL; + map.m_next_extent = NULL; + map.m_seg_type = NO_CHECK_TYPE; + last_lblk = F2FS_BLK_ALIGN(pos + len); + + while (map.m_lblk < last_lblk) { + map.m_len = last_lblk - map.m_lblk; + err = f2fs_map_blocks(inode, &map, 0, F2FS_GET_BLOCK_DEFAULT); + if (err || map.m_len == 0) + return false; + map.m_lblk += map.m_len; + } + return true; +} + static int __get_data_block(struct inode *inode, sector_t iblock, struct buffer_head *bh, int create, int flag, pgoff_t *next_pgofs, int seg_type) @@ -2306,7 +2324,7 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) if (err) return err; - if (__force_buffered_io(inode, rw)) + if (f2fs_force_buffered_io(inode, rw)) return 0; trace_f2fs_direct_IO_enter(inode, offset, count, rw); @@ -2314,7 +2332,15 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) if (rw == WRITE && whint_mode == WHINT_MODE_OFF) iocb->ki_hint = WRITE_LIFE_NOT_SET; - down_read(&F2FS_I(inode)->dio_rwsem[rw]); + if (!down_read_trylock(&F2FS_I(inode)->dio_rwsem[rw])) { + if (iocb->ki_flags & IOCB_NOWAIT) { + iocb->ki_hint = hint; + err = -EAGAIN; + goto out; + } + down_read(&F2FS_I(inode)->dio_rwsem[rw]); + } + err = blockdev_direct_IO(iocb, inode, iter, get_data_block_dio); up_read(&F2FS_I(inode)->dio_rwsem[rw]); @@ -2330,6 +2356,7 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) } } +out: trace_f2fs_direct_IO_exit(inode, offset, count, rw, err); return err; diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 9382263..88f2b42 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -2877,6 +2877,7 @@ int f2fs_release_page(struct page *page, gfp_t wait); int f2fs_migrate_page(struct address_space *mapping, struct page *newpage, struct page *page, enum migrate_mode mode); #endif +bool f2fs_overwrite_io(struct inode *inode, loff_t pos, size_t len); /* * gc.c @@ -3261,4 +3262,11 @@ static inline bool f2fs_may_encrypt(struct inode *inode) #endif } +static inline bool f2fs_force_buffered_io(struct inode *inode, int rw) +{ + return (f2fs_encrypted_file(inode) || + (rw == WRITE && test_opt(F2FS_I_SB(inode), LFS)) || + F2FS_I_SB(inode)->s_ndevs); +} + #endif diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 3072837..c4c27e6 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -480,6 +480,9 @@ static int f2fs_file_open(struct inode *inode, struct file *filp) if (err) return err; + + filp->f_mode |= FMODE_NOWAIT; + return dquot_file_open(inode, filp); } @@ -2896,7 +2899,15 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) if (unlikely(f2fs_cp_error(F2FS_I_SB(inode)))) return -EIO; - inode_lock(inode); + if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT)) + return -EINVAL; + + if (!inode_trylock(inode)) { + if (iocb->ki_flags & IOCB_NOWAIT) + return -EAGAIN; + inode_lock(inode); + } + ret = generic_write_checks(iocb, from); if (ret > 0) { int err; @@ -2904,11 +2915,23 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) if (iov_iter_fault_in_readable(from, iov_iter_count(from))) set_inode_flag(inode, FI_NO_PREALLOC); - err = f2fs_preallocate_blocks(iocb, from); - if (err) { - clear_inode_flag(inode, FI_NO_PREALLOC); - inode_unlock(inode); - return err; + if ((iocb->ki_flags & IOCB_NOWAIT) && + (iocb->ki_flags & IOCB_DIRECT)) { + if (!f2fs_overwrite_io(inode, iocb->ki_pos, + iov_iter_count(from)) || + f2fs_has_inline_data(inode) || + f2fs_force_buffered_io(inode, WRITE)) { + inode_unlock(inode); + return -EAGAIN; + } + + } else { + err = f2fs_preallocate_blocks(iocb, from); + if (err) { + clear_inode_flag(inode, FI_NO_PREALLOC); + inode_unlock(inode); + return err; + } } blk_start_plug(&plug); ret = __generic_file_write_iter(iocb, from); -- 2.7.4