io_uring: avoid touching inode in rw prep

If we use fixed files, we can be sure (almost) that REQ_F_ISREG is set.
However, for non-reg files io_prep_rw() still will look into inode to
double check, and that's expensive and can be avoided.

The only caveat is that it only currently works with 64+ bit
architectures, see FFS_ISREG, so we should consider that.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/0a62780c491ca2522cd52db4ae3f16e03aafed0f.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2021-08-09 13:04:04 +01:00 committed by Jens Axboe
parent b191e2dfe5
commit c97d8a0f68

View File

@ -1231,6 +1231,20 @@ static bool req_need_defer(struct io_kiocb *req, u32 seq)
return false;
}
#define FFS_ASYNC_READ 0x1UL
#define FFS_ASYNC_WRITE 0x2UL
#ifdef CONFIG_64BIT
#define FFS_ISREG 0x4UL
#else
#define FFS_ISREG 0x0UL
#endif
#define FFS_MASK ~(FFS_ASYNC_READ|FFS_ASYNC_WRITE|FFS_ISREG)
static inline bool io_req_ffs_set(struct io_kiocb *req)
{
return IS_ENABLED(CONFIG_64BIT) && (req->flags & REQ_F_FIXED_FILE);
}
static void io_req_track_inflight(struct io_kiocb *req)
{
if (!(req->flags & REQ_F_INFLIGHT)) {
@ -2682,7 +2696,7 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe)
unsigned ioprio;
int ret;
if (!(req->flags & REQ_F_ISREG) && S_ISREG(file_inode(file)->i_mode))
if (!io_req_ffs_set(req) && S_ISREG(file_inode(file)->i_mode))
req->flags |= REQ_F_ISREG;
kiocb->ki_pos = READ_ONCE(sqe->off);
@ -6319,15 +6333,6 @@ static void io_wq_submit_work(struct io_wq_work *work)
}
}
#define FFS_ASYNC_READ 0x1UL
#define FFS_ASYNC_WRITE 0x2UL
#ifdef CONFIG_64BIT
#define FFS_ISREG 0x4UL
#else
#define FFS_ISREG 0x0UL
#endif
#define FFS_MASK ~(FFS_ASYNC_READ|FFS_ASYNC_WRITE|FFS_ISREG)
static inline struct io_fixed_file *io_fixed_file_slot(struct io_file_table *table,
unsigned i)
{