在 2023/3/24 6:12, Andrew Morton 写道:
On Thu, 23 Mar 2023 14:48:25 +0800 Shiyang Ruan <ruansy.fnst@xxxxxxxxxxx> wrote:
在 2023/3/23 7:12, Andrew Morton 写道:
On Wed, 22 Mar 2023 07:25:58 +0000 Shiyang Ruan <ruansy.fnst@xxxxxxxxxxx> wrote:
In an dedupe corporation iter loop, the length of iomap_iter decreases
because it implies the remaining length after each iteration. The
compare function should use the min length of the current iters, not the
total length.
Please describe the user-visible runtime effects of this flaw, thanks.
This patch fixes fail of generic/561, with test config:
export TEST_DEV=/dev/pmem0
export TEST_DIR=/mnt/test
export SCRATCH_DEV=/dev/pmem1
export SCRATCH_MNT=/mnt/scratch
export MKFS_OPTIONS="-m reflink=1,rmapbt=1"
export MOUNT_OPTIONS="-o dax"
export XFS_MOUNT_OPTIONS="-o dax"
Again, how does the bug impact real-world kernel users?
The dedupe command will fail with -EIO if the range is larger than one
page size and not aligned to the page size. Also report warning in dmesg:
[ 4338.498374] ------------[ cut here ]------------
[ 4338.498689] WARNING: CPU: 3 PID: 1415645 at fs/iomap/iter.c:16
iomap_iter+0x2b2/0x2c0
[ 4338.499216] Modules linked in: bfq ext4 mbcache jbd2 auth_rpcgss
oid_registry nfsv4 algif_hash af_alg af_packet nft_reject_inet
nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat
iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set
nf_tables nfnetlink ip6table_filter ip6_tables iptable_filter ip_tables
x_tables nd_pmem nd_btt dax_pmem sch_fq_codel configfs xfs libcrc32c
fuse [last unloaded: scsi_debug]
[ 4338.501419] CPU: 3 PID: 1415645 Comm: pool Kdump: loaded Tainted: G
W 6.1.0-rc4+ #118 242c3ad9724cd53a53c9a3b3cd3050ef1060e37a
[ 4338.502093] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
Arch Linux 1.16.0-3-3 04/01/2014
[ 4338.502610] RIP: 0010:iomap_iter+0x2b2/0x2c0
[ 4338.502933] Code: 0d 63 6f ce 7e 0f 85 d0 fe ff ff e8 f4 ea cc ff e9
c6 fe ff ff 0f 0b e9 a0 fe ff ff 0f 0b e9 a5 fe ff ff 0f 0b e9 85 fe ff
ff <0f> 0b b8 fb ff ff ff e9 aa fe ff ff cc cc 0f 1f 44 00 00 48 8b 42
[ 4338.503963] RSP: 0018:ffffc9000317faa8 EFLAGS: 00010287
[ 4338.504318] RAX: 0000000000000178 RBX: ffffc9000317fba8 RCX:
0000000000001000
[ 4338.504701] RDX: 0000000000000178 RSI: 0000000000399000 RDI:
ffffc9000317fba8
[ 4338.505062] RBP: ffffffffa0321b30 R08: ffffc9000317fae0 R09:
0000000000000000
[ 4338.505490] R10: 0000000000000004 R11: ffff888102577740 R12:
ffffc9000317fd00
[ 4338.505956] R13: 0000000000399000 R14: 0000000000001000 R15:
0000000000000000
[ 4338.506460] FS: 00007f57ce200640(0000) GS:ffff88817bd80000(0000)
knlGS:0000000000000000
[ 4338.507126] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4338.507490] CR2: 00007f57b4a00e88 CR3: 0000000153669002 CR4:
00000000003706e0
[ 4338.507887] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[ 4338.508288] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[ 4338.508717] Call Trace:
[ 4338.508962] <TASK>
[ 4338.509234] dax_dedupe_file_range_compare+0xd9/0x210
[ 4338.509589] __generic_remap_file_range_prep+0x2af/0x760
[ 4338.509942] xfs_reflink_remap_prep+0xeb/0x240 [xfs
4155ff90e551a4608ed7504e9f2aa737a690cfa3]
[ 4338.510505] xfs_file_remap_range+0x83/0x320 [xfs
4155ff90e551a4608ed7504e9f2aa737a690cfa3]
[ 4338.511118] vfs_dedupe_file_range_one+0x196/0x1b0
[ 4338.511407] vfs_dedupe_file_range+0x170/0x1e0
[ 4338.511719] do_vfs_ioctl+0x48d/0x8f0
[ 4338.511975] ? kmem_cache_free+0x2a1/0x460
[ 4338.512278] ? do_sys_openat2+0x7d/0x150
[ 4338.512556] __x64_sys_ioctl+0x40/0xa0
[ 4338.512829] do_syscall_64+0x2b/0x80
[ 4338.513109] entry_SYSCALL_64_after_hwframe+0x46/0xb0
[ 4338.513421] RIP: 0033:0x7f57ce50748f
[ 4338.513687] Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10
00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f
05 <89> c2 3d 00 f0 ff ff 77 18 48 8b 44 24 18 64 48 2b 04 25 28 00 00
[ 4338.514582] RSP: 002b:00007f57ce1ffbb0 EFLAGS: 00000246 ORIG_RAX:
0000000000000010
[ 4338.515067] RAX: ffffffffffffffda RBX: 00007f57b4885870 RCX:
00007f57ce50748f
[ 4338.515441] RDX: 00007f57b4885870 RSI: 00000000c0189436 RDI:
000000000000000e
[ 4338.516300] RBP: 00007f57b486f648 R08: 0000000000000001 R09:
00007f57b486f650
[ 4338.516694] R10: 0000000000000000 R11: 0000000000000246 R12:
00007f57b486f650
[ 4338.517108] R13: 00007f57b486f610 R14: 00007f57b486f650 R15:
00007f57b486f610
[ 4338.518781] </TASK>
[ 4338.519037] ---[ end trace 0000000000000000 ]---
--
Thanks,
Ruan.
Thanks.
