public inbox for [email protected]
 help / color / mirror / Atom feed
From: Xiaoguang Wang <[email protected]>
To: [email protected]
Cc: [email protected], [email protected]
Subject: [PATCH 2/2] io_uring: defer alloc_hint update to io_file_bitmap_set()
Date: Sat, 28 May 2022 00:53:33 +0800	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

io_file_bitmap_get() returns a free bitmap slot, but if it isn't
used later, such as io_queue_rsrc_removal() returns error, in this
case, we should not update alloc_hint at all, which still should
be considered as a valid candidate for next io_file_bitmap_get()
calls.

To fix this issue, only update alloc_hint in io_file_bitmap_set().

Signed-off-by: Xiaoguang Wang <[email protected]>
---
 fs/io_uring.c | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index ff50e5f1753d..811007e055c6 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -5419,15 +5419,11 @@ static int io_file_bitmap_get(struct io_ring_ctx *ctx)
 	unsigned long nr = ctx->nr_user_files;
 	int ret;
 
-	if (table->alloc_hint >= nr)
-		table->alloc_hint = 0;
-
 	do {
 		ret = find_next_zero_bit(table->bitmap, nr, table->alloc_hint);
-		if (ret != nr) {
-			table->alloc_hint = ret + 1;
+		if (ret != nr)
 			return ret;
-		}
+
 		if (!table->alloc_hint)
 			break;
 
@@ -9650,12 +9646,15 @@ static void io_free_file_tables(struct io_file_table *table)
 	table->bitmap = NULL;
 }
 
-static inline void io_file_bitmap_set(struct io_file_table *table, int bit)
+static inline void io_file_bitmap_set(struct io_ring_ctx *ctx, int bit)
 {
+	struct io_file_table *table = &ctx->file_table;
+
 	WARN_ON_ONCE(test_bit(bit, table->bitmap));
 	__set_bit(bit, table->bitmap);
-	if (bit == table->alloc_hint)
-		table->alloc_hint++;
+	table->alloc_hint = bit + 1;
+	if (table->alloc_hint >= ctx->nr_user_files)
+		table->alloc_hint = 0;
 }
 
 static inline void io_file_bitmap_clear(struct io_file_table *table, int bit)
@@ -10080,7 +10079,7 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
 		}
 		file_slot = io_fixed_file_slot(&ctx->file_table, i);
 		io_fixed_file_set(file_slot, file);
-		io_file_bitmap_set(&ctx->file_table, i);
+		io_file_bitmap_set(ctx, i);
 	}
 
 	io_rsrc_node_switch(ctx, NULL);
@@ -10161,7 +10160,7 @@ static int io_install_fixed_file(struct io_kiocb *req, unsigned int issue_flags,
 	if (!ret) {
 		*io_get_tag_slot(ctx->file_data, slot_index) = 0;
 		io_fixed_file_set(file_slot, file);
-		io_file_bitmap_set(&ctx->file_table, slot_index);
+		io_file_bitmap_set(ctx, slot_index);
 	}
 err:
 	if (needs_switch)
@@ -10284,7 +10283,7 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
 			}
 			*io_get_tag_slot(data, i) = tag;
 			io_fixed_file_set(file_slot, file);
-			io_file_bitmap_set(&ctx->file_table, i);
+			io_file_bitmap_set(ctx, i);
 		}
 	}
 
-- 
2.14.4.44.g2045bb6



  parent reply	other threads:[~2022-05-27 16:53 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-27 16:53 [PATCH 0/2] two bug fixes about direct fd install Xiaoguang Wang
2022-05-27 16:53 ` [PATCH 1/2] io_uring: fix file leaks around io_fixed_fd_install() Xiaoguang Wang
2022-05-27 16:53 ` Xiaoguang Wang [this message]
2022-05-27 17:09   ` [PATCH 2/2] io_uring: defer alloc_hint update to io_file_bitmap_set() Jens Axboe
2022-05-27 17:39     ` [PATCH v2] " Xiaoguang Wang
2022-05-27 18:03       ` Jens Axboe
2022-05-28  1:45         ` Xiaoguang Wang
2022-05-28  1:51         ` [PATCH v3] " Xiaoguang Wang
2022-05-28  2:14           ` Jens Axboe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220527165333.55212-3-xiaoguang.wang@linux.alibaba.com \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox