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 <cheol.lee@lge.com>
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Hyunchul Lee 2018-03-08 19:34:38 +09:00 committed by Jaegeuk Kim
parent 63189b7859
commit b91050a80c
3 changed files with 74 additions and 16 deletions

View File

@ -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;

View File

@ -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

View File

@ -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);