Messages in this thread Patch in this message | | | From | Phillip Lougher <> | Subject | Re [PATCH v5 1/2] squashfs: add the mount parameter theads=<single|multi|percpu> | Date | Mon, 17 Oct 2022 22:58:44 +0100 |
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On 30 Sep 2022 17:14:05 +0800 Xiaoming Ni wrote: >Squashfs supports three decompression concurrency modes: > Single-thread mode: concurrent reads are blocked and the memory > overhead is small. > Multi-thread mode/percpu mode: reduces concurrent read blocking but > increases memory overhead. >
You have made another mistake in fixing this patch.
Previously, I asked you to fix patch lines (appearing in V3) which caused a build error.
These lines were:
@@ -446,6 +487,13 @@ static int squashfs_init_fs_context(struct fs_context *fc) if (!opts) return -ENOMEM; +#ifdef CONFIG_SQUASHFS_DECOMP_SINGLE + opts->thread_ops = &squashfs_decompressor_single; +#elif CONFIG_SQUASHFS_DECOMP_MULTI + opts->thread_ops = &squashfs_decompressor_multi; +#elif CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU + opts->thread_ops = &squashfs_decompressor_percpu; +#endif fc->fs_private = opts; fc->ops = &squashfs_context_ops; return 0;
I expected you to replace the
+#elif CONFIG_SQUASHFS_DECOMP_MULTI
line with
+#elif defined(CONFIG_SQUASHFS_DECOMP_MULTI)
and the
+#elif CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU
line with
+#elif defined(CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU)
If you had done that then the patch set would finally have been OK.
Instead you did this in this patch ...
> >@@ -446,6 +487,9 @@ static int squashfs_init_fs_context(struct fs_context *fc) > if (!opts) > return -ENOMEM; > >+#ifdef CONFIG_SQUASHFS_CHOICE_DECOMP_BY_MOUNT >+ opts->thread_ops = &squashfs_decompressor_single; >+#endif > fc->fs_private = opts; > fc->ops = &squashfs_context_ops; > return 0;
You have removed the build error by removing the offending lines.
But, you have rather obviously left opt->thread_ops unassigned if CONFIG_SQUASHFS_CHOICE_DECOMP_BY_MOUNT is not set.
Given the following configuration
CONFIG_SQUASHFS=y # CONFIG_SQUASHFS_FILE_CACHE is not set CONFIG_SQUASHFS_FILE_DIRECT=y CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU=y # CONFIG_SQUASHFS_CHOICE_DECOMP_BY_MOUNT is not set # CONFIG_SQUASHFS_COMPILE_DECOMP_SINGLE is not set # CONFIG_SQUASHFS_COMPILE_DECOMP_MULTI is not set CONFIG_SQUASHFS_COMPILE_DECOMP_MULTI_PERCPU=y CONFIG_SQUASHFS_XATTR=y CONFIG_SQUASHFS_ZLIB=y CONFIG_SQUASHFS_LZ4=y CONFIG_SQUASHFS_LZO=y CONFIG_SQUASHFS_XZ=y CONFIG_SQUASHFS_ZSTD=y # CONFIG_SQUASHFS_4K_DEVBLK_SIZE is not set # CONFIG_SQUASHFS_EMBEDDED is not set CONFIG_SQUASHFS_FRAGMENT_CACHE_SIZE=3
You will get the following kernel oops with this patch applied.
root@logopolis:~# mount -t squashfs /dev/sdb /mnt BUG: kernel NULL pointer dereference, address: 0000000000000018 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 8000000004db0067 P4D 8000000004db0067 PUD 5bf0067 PMD 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 3 PID: 1482 Comm: mount Not tainted 6.0.0+ #38 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 RIP: 0010:squashfs_fill_super+0x2d5/0x700 Code: e0 c9 02 82 e8 2c d0 ff ff 48 89 43 10 48 89 c7 48 85 c0 0f 84 10 03 00 00 8b 93 98 00 00 00 48 8b 83 c0 00 00 00 89 54 24 04 <48> 8b 40 18 e8 12 51 b8 00 8b 54 24 04 48 c7 c7 86 fb 21 82 89 c6 RSP: 0018:ffffc900024e7de0 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff88800611b300 RCX: 00000000000003db RDX: 0000000000100000 RSI: 0000000000000cc0 RDI: ffff888004411600 RBP: ffff888004689000 R08: ffff888004411900 R09: 0000000000000000 R10: ffff88800440f450 R11: 0000000000024298 R12: ffff888004ea9540 R13: 000002c12876123d R14: ffff8880044115a0 R15: 00000000000000c0 FS: 00007f99343ea840(0000) GS:ffff88807dd80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000018 CR3: 00000000046ea000 CR4: 00000000000006e0 Call Trace: <TASK> ? squashfs_init_fs_context+0x40/0x40 get_tree_bdev+0x16a/0x260 vfs_get_tree+0x20/0xb0 path_mount+0x2d3/0xa70 __x64_sys_mount+0x194/0x1f0 do_syscall_64+0x43/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f9933621d8a Code: 48 8b 0d 01 c1 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ce c0 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd3d78d138 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007ffd3d78d260 RCX: 00007f9933621d8a RDX: 00000000006191e0 RSI: 00000000006191c0 RDI: 00000000006191a0 RBP: 00000000c0ed0000 R08: 0000000000000000 R09: 0000000000619300 R10: ffffffffc0ed0000 R11: 0000000000000202 R12: 00000000006191c0 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> Modules linked in: CR2: 0000000000000018 ---[ end trace 0000000000000000 ]--- RIP: 0010:squashfs_fill_super+0x2d5/0x700 Code: e0 c9 02 82 e8 2c d0 ff ff 48 89 43 10 48 89 c7 48 85 c0 0f 84 10 03 00 00 8b 93 98 00 00 00 48 8b 83 c0 00 00 00 89 54 24 04 <48> 8b 40 18 e8 12 51 b8 00 8b 54 24 04 48 c7 c7 86 fb 21 82 89 c6 RSP: 0018:ffffc900024e7de0 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff88800611b300 RCX: 00000000000003db RDX: 0000000000100000 RSI: 0000000000000cc0 RDI: ffff888004411600 RBP: ffff888004689000 R08: ffff888004411900 R09: 0000000000000000 R10: ffff88800440f450 R11: 0000000000024298 R12: ffff888004ea9540 R13: 000002c12876123d R14: ffff8880044115a0 R15: 00000000000000c0 FS: 00007f99343ea840(0000) GS:ffff88807dd80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000018 CR3: 00000000046ea000 CR4: 00000000000006e0 Killed I do not understand why you have not fixed the patch as I have asked, and instead repeatedly sent patches which are obviously broken.
Cheers
Phillip
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