On 7/26/23 18:25, Hao Xu wrote:
From: Hao Xu <howeyxu@xxxxxxxxxxx> This series adds lseek for io_uring, the motivation to import this syscall is in previous io_uring getdents patchset, we lack a way to rewind the file cursor when it goes to the end of file. Another reason is lseek is a common syscall, it's good for coding consistency when users use io_uring as their main loop. Patch 1 is code clean for iomap Patch 2 adds IOMAP_NOWAIT logic for iomap lseek Patch 3 adds a nowait parameter to for IOMAP_NOWAIT control Patch 4 adds llseek_nowait() for file_operations so that specific filesystem can implement it for nowait lseek Patch 5 adds llseek_nowait() implementation for xfs Patch 6 adds a new vfs wrapper for io_uring use Patch 7 is the main io_uring lseek implementation Note, this series depends on the previous io_uring getdents series. This is marked RFC since there is (at least) an issue to be discussed: The work in this series is mainly to reslove a problem that the current llseek() in struct file_operations doesn't have a place to deliver nowait info, and adding an argument to it results in update for llseek implementation of all filesystems (35 functions), so here I introduce a new llseek_nowait() as a workaround. For performance, it has about 20%~30% improvement on iops. The test program is just like the one for io_uring getdents, here is the link to it: https://github.com/HowHsu/liburing/blob/llseek/test/lseek.c - Each test runs about 30000 async requests/sync syscalls - Each test runs 100 times and get the average value. - offset is randomly generated value - the file is a 1M all zero file [howeyxu@~]$ python3 run_lseek.py test args: seek mode:SEEK_SET, offset: 334772 Average of sync : 0.012300650000000002 Average of iouring : 0.008528009999999999 30.67% [howeyxu@~]$ python3 run_lseek.py test args: seek mode:SEEK_CUR, offset: 389292 Average of sync : 0.012736129999999995 Average of iouring : 0.00928725 27.08% [howeyxu@~]$ python3 run_lseek.py test args: seek mode:SEEK_END, offset: 281141 Average of sync : 0.01221595 Average of iouring : 0.008442890000000003 30.89% [howeyxu@~]$ python3 run_lseek.py test args: seek mode:SEEK_DATA, offset: 931103 Average of sync : 0.015496230000000005 Average of iouring : 0.012341509999999998 20.36% [howeyxu@~]$ python3 run_lseek.py test args: seek mode:SEEK_HOLE, offset: 430194 Average of sync : 0.01555663000000001 Average of iouring : 0.012064940000000003 22.45%Hao Xu (7): iomap: merge iomap_seek_hole() and iomap_seek_data() xfs: add nowait support for xfs_seek_iomap_begin() add nowait parameter for iomap_seek() add llseek_nowait() for struct file_operations add llseek_nowait support for xfs add vfs_lseek_nowait() add lseek for io_uring fs/ext4/file.c | 9 ++--- fs/gfs2/inode.c | 4 +-- fs/iomap/seek.c | 42 ++++++----------------- fs/read_write.c | 18 ++++++++++ fs/xfs/xfs_file.c | 34 ++++++++++++++++--- fs/xfs/xfs_iomap.c | 4 ++- include/linux/fs.h | 4 +++ include/linux/iomap.h | 6 ++-- include/uapi/linux/io_uring.h | 1 + io_uring/fs.c | 63 +++++++++++++++++++++++++++++++++++ io_uring/fs.h | 3 ++ io_uring/opdef.c | 8 +++++ 12 files changed, 145 insertions(+), 51 deletions(-) base-commit: 4a4b046082eca8ae90b654d772fccc30e9f23f4d
Hi folks, I'll leave this patchset here before the io_uring getdents is merged, then come back and update this one. Thanks, Hao
