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AJvYcCUvwzDf88Qz8giMUHJ5GzBstpBRpCPp0ebUP/hiVJld6UhKP832fZrvLMJqdj4Jtzi2soMUCbbGZusiK1ey@vger.kernel.org X-Gm-Message-State: AOJu0YzaqNSpqo1xES/acqEUICJ3StpZK9kdrF152Xtd9Nj5qfhKC7yf 0e3ZUsonD8HJWwNLMpdvlboiRmGbCiyiOG9fJGfgxkt3zSx4rm/C8tlk9etfQiy3Mh/oT3F8TYe UeqCbxLvu3BIVpB8HLHOEFgg2ldtRudZgrNIRBc1d/nA4fzei0h0/du9zgYk= Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:1f08:b0:67e:20e3:46fd with SMTP id 006d021491bc7-67e20e34743mr5280205eaf.51.1774856323095; Mon, 30 Mar 2026 00:38:43 -0700 (PDT) Date: Mon, 30 Mar 2026 00:38:43 -0700 In-Reply-To: <20260329172002.3557801-1-mjguzik@gmail.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69ca2883.a70a0220.97f31.014d.GAE@google.com> Subject: [syzbot ci] Re: assorted ->i_count changes + extension of lockless handling From: syzbot ci To: brauner@kernel.org, jack@suse.cz, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, mjguzik@gmail.com, viro@zeniv.linux.org.uk Cc: syzbot@lists.linux.dev, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" syzbot ci has tested the following series [v3] assorted ->i_count changes + extension of lockless handling https://lore.kernel.org/all/20260329172002.3557801-1-mjguzik@gmail.com * [PATCH v3 1/7] fs: add icount_read_once() * [PATCH v3 2/7] Use icount_read() and icount_read_once() as appropriate. * [PATCH v3 3/7] fs: enforce locking in icount_read(), add some commentary * [PATCH v3 4/7] fs: relocate and tidy up ihold() * [PATCH v3 5/7] fs: handle hypothetical filesystems which use I_DONTCACHE and drop the lock in ->drop_inode * [PATCH v3 6/7] fs: locklessly bump refs in igrab as long as it does not transition 0->1 * [PATCH v3 7/7] fs: locklessly bump refs in the inode hash when possible and found the following issue: WARNING in bdev_file_open_by_dev Full report is available here: https://ci.syzbot.org/series/ed1deb86-adfc-43a1-bec0-01d8189f1e9f *** WARNING in bdev_file_open_by_dev tree: linux-next URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next base: 3b058d1aeeeff27a7289529c4944291613b364e9 arch: amd64 compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 config: https://ci.syzbot.org/builds/84ba2ea1-23ea-425b-8339-8acab8f7ad4b/config 9p: Installing v9fs 9p2000 file system support NILFS version 2 loaded befs: version: 0.9.3 ocfs2: Registered cluster interface o2cb ocfs2: Registered cluster interface user OCFS2 User DLM kernel interface loaded gfs2: GFS2 installed ceph: loaded (mds proto 32) cryptd: max_cpu_qlen set to 1000 NET: Registered PF_ALG protocol family async_tx: api initialized (async) Key type asymmetric registered Asymmetric key parser 'x509' registered Asymmetric key parser 'pkcs8' registered Key type pkcs7_test registered Block layer SCSI generic (bsg) driver version 0.4 loaded (major 239) io scheduler mq-deadline registered io scheduler kyber registered io scheduler bfq registered xor: measuring software checksum speed prefetch64-sse : 6910 MB/sec sse : 6480 MB/sec xor: using function: prefetch64-sse (6910 MB/sec) input: Power Button as /devices/platform/LNXPWRBN:00/input/input0 ACPI: button: Power Button [PWRF] ioatdma: Intel(R) QuickData Technology Driver 5.00 ACPI: \_SB_.GSIG: Enabled at IRQ 22 N_HDLC line discipline registered with maxframe=4096 Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled 00:03: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A Non-volatile memory driver v1.3 Linux agpgart interface v0.103 usbcore: registered new interface driver xillyusb ACPI: bus type drm_connector registered [drm] Initialized vgem 1.0.0 for vgem on minor 0 [drm] Initialized vkms 1.0.0 for vkms on minor 1 Console: switching to colour frame buffer device 128x48 faux_driver vkms: [drm] fb0: vkmsdrmfb frame buffer device usbcore: registered new interface driver udl bochs-drm 0000:00:01.0: vgaarb: deactivate vga console [drm] Found bochs VGA, ID 0xb0c5. [drm] Framebuffer size 16384 kB @ 0xfd000000, mmio @ 0xfebf0000. [drm] Initialized bochs-drm 1.0.0 for 0000:00:01.0 on minor 2 fbcon: bochs-drmdrmfb (fb1) is primary device fbcon: Remapping primary device, fb1, to tty 1-63 bochs-drm 0000:00:01.0: [drm] fb1: bochs-drmdrmfb frame buffer device usbcore: registered new interface driver gm12u320 usbcore: registered new interface driver gud ------------[ cut here ]------------ debug_locks && !(lock_is_held(&(&inode->i_lock)->dep_map) != 0) WARNING: ./include/linux/fs.h:2242 at ihold+0x102/0x170, CPU#1: swapper/0/1 Modules linked in: CPU: 1 UID: 0 PID: 1 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:ihold+0x102/0x170 Code: b7 7c ff 83 fb 02 7c 11 e8 2b b3 7c ff 5b 41 5e 41 5f 5d e9 c0 e0 6b 09 cc e8 1a b3 7c ff 90 0f 0b 90 eb e9 e8 0f b3 7c ff 90 <0f> 0b 90 e9 6d ff ff ff 48 c7 c1 e0 bd 12 90 80 e1 07 80 c1 03 38 RSP: 0000:ffffc90000067680 EFLAGS: 00010293 RAX: ffffffff82496f71 RBX: ffff888167cb06a0 RCX: ffff888102a957c0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff888167cb08a7 R09: 1ffff1102cf96114 R10: dffffc0000000000 R11: ffffed102cf96115 R12: ffff888167cb0000 R13: ffff888169632e00 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8882a943f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000000e54a000 CR4: 00000000000006f0 Call Trace: bdev_file_open_by_dev+0x1aa/0x240 disk_scan_partitions+0x1c1/0x2c0 add_disk_fwnode+0x321/0x480 brd_alloc+0x5b9/0x7c0 brd_init+0xc1/0x120 do_one_initcall+0x250/0x870 do_initcall_level+0x104/0x190 do_initcalls+0x59/0xa0 kernel_init_freeable+0x2a6/0x3e0 kernel_init+0x1d/0x1d0 ret_from_fork+0x514/0xb70 ret_from_fork_asm+0x1a/0x30 *** If these findings have caused you to resend the series or submit a separate fix, please add the following tag to your commit message: Tested-by: syzbot@syzkaller.appspotmail.com --- This report is generated by a bot. It may contain errors. syzbot ci engineers can be reached at syzkaller@googlegroups.com.