On 11/29/21 5:08 PM, Clay Harris wrote: > On Mon, Nov 29 2021 at 14:12:52 -0800, Stefan Roesch quoth thus: > >> This adds the xattr support to io_uring. The intent is to have a more >> complete support for file operations in io_uring. >> >> This change adds support for the following functions to io_uring: >> - fgetxattr >> - fsetxattr >> - getxattr >> - setxattr > > You may wish to consider the following. > > Patching for these functions makes for an excellent opportunity > to provide a better interface. Rather than implement fXetattr > at all, you could enable io_uring to use functions like: > > int Xetxattr(int dfd, const char *path, const char *name, > [const] void *value, size_t size, int flags); > > Not only does this simplify the io_uring interface down to two > functions, but modernizes and fixes a deficit in usability. > In terms of io_uring, this is just changing internal interfaces. > > Although unnecessary for io_uring, it would be nice to at least > consider what parts of this code could be leveraged for future > Xetxattr2 syscalls. Clay, while we can reduce the number of calls to 2, providing 4 calls will ease the adoption of the interface. If you look at the userspace interface in liburing, you can see the following function signature: static inline void io_uring_prep_fgetxattr(struct io_uring_sqe *sqe, int fd, const char *name, const char *value, size_t len) This is very similar to what you proposed. > >> Patch 1: fs: make user_path_at_empty() take a struct filename >> The user_path_at_empty filename parameter has been changed >> from a const char user pointer to a filename struct. io_uring >> operates on filenames. >> In addition also the functions that call user_path_at_empty >> in namei.c and stat.c have been modified for this change. >> >> Patch 2: fs: split off setxattr_setup function from setxattr >> Split off the setup part of the setxattr function >> >> Patch 3: fs: split off the vfs_getxattr from getxattr >> Split of the vfs_getxattr part from getxattr. This will >> allow to invoke it from io_uring. >> >> Patch 4: io_uring: add fsetxattr and setxattr support >> This adds new functions to support the fsetxattr and setxattr >> functions. >> >> Patch 5: io_uring: add fgetxattr and getxattr support >> This adds new functions to support the fgetxattr and getxattr >> functions. >> >> >> There are two additional patches: >> liburing: Add support for xattr api's. >> This also includes the tests for the new code. >> xfstests: Add support for io_uring xattr support. >> >> >> Stefan Roesch (5): >> fs: make user_path_at_empty() take a struct filename >> fs: split off setxattr_setup function from setxattr >> fs: split off the vfs_getxattr from getxattr >> io_uring: add fsetxattr and setxattr support >> io_uring: add fgetxattr and getxattr support >> >> fs/internal.h | 23 +++ >> fs/io_uring.c | 325 ++++++++++++++++++++++++++++++++++ >> fs/namei.c | 5 +- >> fs/stat.c | 7 +- >> fs/xattr.c | 114 +++++++----- >> include/linux/namei.h | 4 +- >> include/uapi/linux/io_uring.h | 8 +- >> 7 files changed, 439 insertions(+), 47 deletions(-) >> >> >> Signed-off-by: Stefan Roesch <shr@xxxxxx> >> base-commit: c2626d30f312afc341158e07bf088f5a23b4eeeb >> -- >> 2.30.2
