From: Hao Xu <howeyxu@xxxxxxxxxxx> This series introduce getdents64 to io_uring, the code logic is similar with the snychronized version's. It first try nowait issue, and offload it to io-wq threads if the first try fails. Patch1 and Patch2 are some preparation Patch3 supports nowait for xfs getdents code Patch4-11 are vfs change, include adding helpers and trylock for locks Tests I've done: A liburing test case for functional test: https://github.com/HowHsu/liburing/commit/39dc9a8e19c06a8cebf8c2301b85320eb45c061e?diff=unified Tested it with a liburing performance test: https://github.com/HowHsu/liburing/blob/getdents/test/getdents2.c The test is controlled by the below script[2] which runs getdents2.t 100 times and calulate the avg. The result show that io_uring version is about 2.6% faster: note: [1] the number of getdents call/request in io_uring and normal sync version are made sure to be same beforehand. [2] run_getdents.py ```python3 import subprocess N = 100 sum = 0.0 args = ["/data/home/howeyxu/tmpdir", "sync"] for i in range(N): output = subprocess.check_output(["./liburing/test/getdents2.t"] + args) sum += float(output) average = sum / N print("Average of sync:", average) sum = 0.0 args = ["/data/home/howeyxu/tmpdir", "iouring"] for i in range(N): output = subprocess.check_output(["./liburing/test/getdents2.t"] + args) sum += float(output) average = sum / N print("Average of iouring:", average) ``` v5->v6: - remove xfs journal stuff since there are fundamental issues in the design. v4->v5: - move atime update to the beginning of getdents operation - trylock for i_rwsem - nowait semantics for involved xfs journal stuff v3->v4: - add Dave's xfs nowait code and fix a deadlock problem, with some code style tweak. - disable fixed file to avoid a race problem for now - add a test program. v2->v3: - removed the kernfs patches - add f_pos_lock logic - remove the "reduce last EOF getdents try" optimization since Dominique reports that doesn't make difference - remove the rewind logic, I think the right way is to introduce lseek to io_uring not to patch this logic to getdents. - add Singed-off-by of Stefan Roesch for patch 1 since checkpatch complained that Co-developed-by someone should be accompanied with Signed-off-by same person, I can remove them if Stefan thinks that's not proper. Dominique Martinet (1): fs: split off vfs_getdents function of getdents64 syscall Hao Xu (10): xfs: add NOWAIT semantics for readdir vfs: add nowait flag for struct dir_context vfs: add a vfs helper for io_uring file pos lock vfs: add file_pos_unlock() for io_uring usage vfs: add a nowait parameter for touch_atime() vfs: add nowait parameter for file_accessed() vfs: move file_accessed() to the beginning of iterate_dir() vfs: error out -EAGAIN if atime needs to be updated vfs: trylock inode->i_rwsem in iterate_dir() to support nowait io_uring: add support for getdents arch/s390/hypfs/inode.c | 2 +- block/fops.c | 2 +- fs/btrfs/file.c | 2 +- fs/btrfs/inode.c | 2 +- fs/cachefiles/namei.c | 2 +- fs/coda/dir.c | 4 +-- fs/ecryptfs/file.c | 4 +-- fs/ext2/file.c | 4 +-- fs/ext4/file.c | 6 ++-- fs/f2fs/file.c | 4 +-- fs/file.c | 13 ++++++++ fs/fuse/dax.c | 2 +- fs/fuse/file.c | 4 +-- fs/gfs2/file.c | 2 +- fs/hugetlbfs/inode.c | 2 +- fs/inode.c | 10 ++++-- fs/internal.h | 8 +++++ fs/namei.c | 4 +-- fs/nfsd/vfs.c | 2 +- fs/nilfs2/file.c | 2 +- fs/orangefs/file.c | 2 +- fs/orangefs/inode.c | 2 +- fs/overlayfs/file.c | 2 +- fs/overlayfs/inode.c | 2 +- fs/pipe.c | 2 +- fs/ramfs/file-nommu.c | 2 +- fs/readdir.c | 61 ++++++++++++++++++++++++++-------- fs/smb/client/cifsfs.c | 2 +- fs/splice.c | 2 +- fs/stat.c | 2 +- fs/ubifs/file.c | 2 +- fs/udf/file.c | 2 +- fs/xfs/libxfs/xfs_da_btree.c | 16 +++++++++ fs/xfs/libxfs/xfs_da_btree.h | 1 + fs/xfs/libxfs/xfs_dir2_block.c | 7 ++-- fs/xfs/libxfs/xfs_dir2_priv.h | 2 +- fs/xfs/scrub/dir.c | 2 +- fs/xfs/scrub/readdir.c | 2 +- fs/xfs/xfs_dir2_readdir.c | 49 +++++++++++++++++++++------ fs/xfs/xfs_file.c | 6 ++-- fs/xfs/xfs_inode.c | 27 +++++++++++++++ fs/xfs/xfs_inode.h | 17 ++++++---- fs/zonefs/file.c | 4 +-- include/linux/file.h | 7 ++++ include/linux/fs.h | 15 +++++++-- include/uapi/linux/io_uring.h | 1 + io_uring/fs.c | 53 +++++++++++++++++++++++++++++ io_uring/fs.h | 3 ++ io_uring/opdef.c | 8 +++++ kernel/bpf/inode.c | 4 +-- mm/filemap.c | 8 ++--- mm/shmem.c | 6 ++-- net/unix/af_unix.c | 4 +-- 53 files changed, 310 insertions(+), 96 deletions(-) -- 2.25.1
