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authorLinus Torvalds <torvalds@linux-foundation.org>2020-05-01 17:03:06 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-05-01 17:03:06 -0700
commitcf0185308c41a307a4e7b37b6690d30735fa16a6 (patch)
treecf2ccc8354d6fccb4650318ccd8b817a8155268a
parent052c467cb58748e302a95546925928e637025acc (diff)
parent2fb3e82284fca40afbde5351907f0a5b3be717f9 (diff)
downloadlinux-stericsson-cf0185308c41a307a4e7b37b6690d30735fa16a6.tar.gz
Merge tag 'io_uring-5.7-2020-05-01' of git://git.kernel.dk/linux-block
Pull io_uring fixes from Jens Axboe: - Fix for statx not grabbing the file table, making AT_EMPTY_PATH fail - Cover a few cases where async poll can handle retry, eliminating the need for an async thread - fallback request busy/free fix (Bijan) - syzbot reported SQPOLL thread exit fix for non-preempt (Xiaoguang) - Fix extra put of req for sync_file_range (Pavel) - Always punt splice async. We'll improve this for 5.8, but wanted to eliminate the inode mutex lock from the non-blocking path for 5.7 (Pavel) * tag 'io_uring-5.7-2020-05-01' of git://git.kernel.dk/linux-block: io_uring: punt splice async because of inode mutex io_uring: check non-sync defer_list carefully io_uring: fix extra put in sync_file_range() io_uring: use cond_resched() in io_ring_ctx_wait_and_kill() io_uring: use proper references for fallback_req locking io_uring: only force async punt if poll based retry can't handle it io_uring: enable poll retry for any file with ->read_iter / ->write_iter io_uring: statx must grab the file table for valid fd
-rw-r--r--fs/io_uring.c58
1 files changed, 31 insertions, 27 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index c687f57fb651..0b91b0631173 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -524,6 +524,7 @@ enum {
REQ_F_OVERFLOW_BIT,
REQ_F_POLLED_BIT,
REQ_F_BUFFER_SELECTED_BIT,
+ REQ_F_NO_FILE_TABLE_BIT,
/* not a real bit, just to check we're not overflowing the space */
__REQ_F_LAST_BIT,
@@ -577,6 +578,8 @@ enum {
REQ_F_POLLED = BIT(REQ_F_POLLED_BIT),
/* buffer already selected */
REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT),
+ /* doesn't need file table for this request */
+ REQ_F_NO_FILE_TABLE = BIT(REQ_F_NO_FILE_TABLE_BIT),
};
struct async_poll {
@@ -799,6 +802,7 @@ static const struct io_op_def io_op_defs[] = {
.needs_file = 1,
.fd_non_neg = 1,
.needs_fs = 1,
+ .file_table = 1,
},
[IORING_OP_READ] = {
.needs_mm = 1,
@@ -1291,7 +1295,7 @@ static struct io_kiocb *io_get_fallback_req(struct io_ring_ctx *ctx)
struct io_kiocb *req;
req = ctx->fallback_req;
- if (!test_and_set_bit_lock(0, (unsigned long *) ctx->fallback_req))
+ if (!test_and_set_bit_lock(0, (unsigned long *) &ctx->fallback_req))
return req;
return NULL;
@@ -1378,7 +1382,7 @@ static void __io_free_req(struct io_kiocb *req)
if (likely(!io_is_fallback_req(req)))
kmem_cache_free(req_cachep, req);
else
- clear_bit_unlock(0, (unsigned long *) req->ctx->fallback_req);
+ clear_bit_unlock(0, (unsigned long *) &req->ctx->fallback_req);
}
struct req_batch {
@@ -2034,7 +2038,7 @@ static struct file *__io_file_get(struct io_submit_state *state, int fd)
* any file. For now, just ensure that anything potentially problematic is done
* inline.
*/
-static bool io_file_supports_async(struct file *file)
+static bool io_file_supports_async(struct file *file, int rw)
{
umode_t mode = file_inode(file)->i_mode;
@@ -2043,7 +2047,13 @@ static bool io_file_supports_async(struct file *file)
if (S_ISREG(mode) && file->f_op != &io_uring_fops)
return true;
- return false;
+ if (!(file->f_mode & FMODE_NOWAIT))
+ return false;
+
+ if (rw == READ)
+ return file->f_op->read_iter != NULL;
+
+ return file->f_op->write_iter != NULL;
}
static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
@@ -2571,7 +2581,7 @@ static int io_read(struct io_kiocb *req, bool force_nonblock)
* If the file doesn't support async, mark it as REQ_F_MUST_PUNT so
* we know to async punt it even if it was opened O_NONBLOCK
*/
- if (force_nonblock && !io_file_supports_async(req->file))
+ if (force_nonblock && !io_file_supports_async(req->file, READ))
goto copy_iov;
iov_count = iov_iter_count(&iter);
@@ -2594,7 +2604,8 @@ copy_iov:
if (ret)
goto out_free;
/* any defer here is final, must blocking retry */
- if (!(req->flags & REQ_F_NOWAIT))
+ if (!(req->flags & REQ_F_NOWAIT) &&
+ !file_can_poll(req->file))
req->flags |= REQ_F_MUST_PUNT;
return -EAGAIN;
}
@@ -2662,7 +2673,7 @@ static int io_write(struct io_kiocb *req, bool force_nonblock)
* If the file doesn't support async, mark it as REQ_F_MUST_PUNT so
* we know to async punt it even if it was opened O_NONBLOCK
*/
- if (force_nonblock && !io_file_supports_async(req->file))
+ if (force_nonblock && !io_file_supports_async(req->file, WRITE))
goto copy_iov;
/* file path doesn't support NOWAIT for non-direct_IO */
@@ -2716,7 +2727,8 @@ copy_iov:
if (ret)
goto out_free;
/* any defer here is final, must blocking retry */
- req->flags |= REQ_F_MUST_PUNT;
+ if (!file_can_poll(req->file))
+ req->flags |= REQ_F_MUST_PUNT;
return -EAGAIN;
}
}
@@ -2756,15 +2768,6 @@ static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
return 0;
}
-static bool io_splice_punt(struct file *file)
-{
- if (get_pipe_info(file))
- return false;
- if (!io_file_supports_async(file))
- return true;
- return !(file->f_flags & O_NONBLOCK);
-}
-
static int io_splice(struct io_kiocb *req, bool force_nonblock)
{
struct io_splice *sp = &req->splice;
@@ -2774,11 +2777,8 @@ static int io_splice(struct io_kiocb *req, bool force_nonblock)
loff_t *poff_in, *poff_out;
long ret;
- if (force_nonblock) {
- if (io_splice_punt(in) || io_splice_punt(out))
- return -EAGAIN;
- flags |= SPLICE_F_NONBLOCK;
- }
+ if (force_nonblock)
+ return -EAGAIN;
poff_in = (sp->off_in == -1) ? NULL : &sp->off_in;
poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;
@@ -3355,8 +3355,12 @@ static int io_statx(struct io_kiocb *req, bool force_nonblock)
struct kstat stat;
int ret;
- if (force_nonblock)
+ if (force_nonblock) {
+ /* only need file table for an actual valid fd */
+ if (ctx->dfd == -1 || ctx->dfd == AT_FDCWD)
+ req->flags |= REQ_F_NO_FILE_TABLE;
return -EAGAIN;
+ }
if (vfs_stat_set_lookup_flags(&lookup_flags, ctx->how.flags))
return -EINVAL;
@@ -3502,7 +3506,7 @@ static void io_sync_file_range_finish(struct io_wq_work **workptr)
if (io_req_cancelled(req))
return;
__io_sync_file_range(req);
- io_put_req(req); /* put submission ref */
+ io_steal_work(req, workptr);
}
static int io_sync_file_range(struct io_kiocb *req, bool force_nonblock)
@@ -5015,7 +5019,7 @@ static int io_req_defer(struct io_kiocb *req, const struct io_uring_sqe *sqe)
int ret;
/* Still need defer if there is pending req in defer list. */
- if (!req_need_defer(req) && list_empty(&ctx->defer_list))
+ if (!req_need_defer(req) && list_empty_careful(&ctx->defer_list))
return 0;
if (!req->io && io_alloc_async_ctx(req))
@@ -5429,7 +5433,7 @@ static int io_grab_files(struct io_kiocb *req)
int ret = -EBADF;
struct io_ring_ctx *ctx = req->ctx;
- if (req->work.files)
+ if (req->work.files || (req->flags & REQ_F_NO_FILE_TABLE))
return 0;
if (!ctx->ring_file)
return -EBADF;
@@ -7327,7 +7331,7 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
* it could cause shutdown to hang.
*/
while (ctx->sqo_thread && !wq_has_sleeper(&ctx->sqo_wait))
- cpu_relax();
+ cond_resched();
io_kill_timeouts(ctx);
io_poll_remove_all(ctx);