On 08/29/2017 11:12 AM, NeilBrown wrote:
On Tue, Aug 29 2017, Zhilong Liu wrote:
Hi, Neil;
Thanks for your pointing and sorry for the incorrect dmesg for last
mail.
Here update the pure steps and paste the dmesg.
ENV:
OS: 4.13-rc7 upstream
linux-apta:~/mdadm-test # df -T /mnt/
Filesystem Type 1K-blocks Used Available Use% Mounted on
/dev/sda2 ext4 44248848 24416952 18778472 57% /
Reproduce: 100%
Steps:
linux-apta:~/mdadm-test # ./mdadm -CR /dev/md0 -l1 -b /mnt/3 -n2 -x1
/dev/loop[0-2] --force
mdadm: Note: this array has metadata at the start and
may not be suitable as a boot device. If you plan to
store '/boot' on this device please ensure that
your boot-loader understands md/v1.x metadata, or use
--metadata=0.90
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.
linux-apta:~/mdadm-test # cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 loop2[2](S) loop1[1] loop0[0]
18944 blocks super 1.2 [2/2] [UU]
bitmap: 3/3 pages [12KB], 4KB chunk, file: /mnt/3
unused devices: <none>
linux-apta:~/mdadm-test # dmesg -c
[ 181.378209] md/raid1:md0: not clean -- starting background reconstruction
[ 181.378211] md/raid1:md0: active with 2 out of 2 mirrors
[ 181.379354] md0: detected capacity change from 0 to 19398656
[ 181.379773] md: resync of RAID array md0
[ 190.396162] md: md0: resync done.
linux-apta:~/mdadm-test # ./mdadm --grow /dev/md0 --size 128
Segmentation fault
linux-apta:~/mdadm-test # cat /sys/block/md0/md/component_size
18944 "here is incorrect also."
linux-apta:~/mdadm-test # dmesg -c
[ 208.027505] ------------[ cut here ]------------
[ 208.027508] kernel BUG at drivers/md/bitmap.c:298!
Thanks. Less confusing now.
The problem is that when the bitmap is resized, new pages are allocated
to store the on-disk copy, but these are not read from the file, the
contents are set from the in-memory bitmap.
So read_page() isn't called and particularly
bh = alloc_page_buffers(page, 1<<inode->i_blkbits, 0);
...
attach_page_buffers(page, bh);
doesn't happen.
Maybe something like this will work.
Can you test it?
Another panic happens when I built with the below patch.
Steps:
1. patching the codes to bitmap.c
2. rebuilt the kernel source code.
3. reboot and test.
linux-apta:~/mdadm-test # ./mdadm -CR /dev/md0 -l1 -b /mnt/3 -n2 -x1
/dev/loop[0-2] --force
mdadm: Note: this array has metadata at the start and
may not be suitable as a boot device. If you plan to
store '/boot' on this device please ensure that
your boot-loader understands md/v1.x metadata, or use
--metadata=0.90
mdadm: Defaulting to version 1.2 metadata
Segmentation fault
linux-apta:~/mdadm-test # dmesg -c
[ 46.416567] md/raid1:md0: not clean -- starting background reconstruction
[ 46.416570] md/raid1:md0: active with 2 out of 2 mirrors
[ 46.417003] ------------[ cut here ]------------
[ 46.417004] kernel BUG at drivers/md/bitmap.c:371!
[ 46.417007] invalid opcode: 0000 [#1] SMP
[ 46.417009] Modules linked in: raid1(E) md_mod(E) loop(E) uinput(E)
af_packet(E) iscsi_ibft(E) iscsi_boot_sysfs(E) crct10dif_pclmul(E)
snd_hda_codec_generic(E) crc32_pclmul(E) snd_hda_intel(E)
snd_hda_codec(E) snd_hda_core(E) crc32c_intel(E) snd_hwdep(E)
ghash_clmulni_intel(E) snd_pcm(E) pcbc(E) snd_timer(E) snd(E)
aesni_intel(E) ppdev(E) parport_pc(E) aes_x86_64(E) virtio_balloon(E)
joydev(E) virtio_net(E) soundcore(E) i2c_piix4(E) pcspkr(E)
crypto_simd(E) parport(E) button(E) glue_helper(E) cryptd(E) pvpanic(E)
ext4(E) crc16(E) mbcache(E) jbd2(E) hid_generic(E) usbhid(E)
ata_generic(E) sd_mod(E) virtio_console(E) virtio_scsi(E) ata_piix(E)
ahci(E) libahci(E) serio_raw(E) libata(E) ehci_pci(E) virtio_pci(E)
virtio_ring(E) virtio(E) qxl(E) drm_kms_helper(E) syscopyarea(E)
sysfillrect(E) sysimgblt(E)
[ 46.417040] uhci_hcd(E) fb_sys_fops(E) ehci_hcd(E) ttm(E) usbcore(E)
drm(E) floppy(E) sg(E) dm_multipath(E) dm_mod(E) scsi_dh_rdac(E)
scsi_dh_emc(E) scsi_dh_alua(E) scsi_mod(E) autofs4(E)
[ 46.417050] CPU: 2 PID: 1858 Comm: mdadm Tainted: G E
4.13.0-rc7-up-latest #1
[ 46.417051] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS Bochs 01/01/2011
[ 46.417053] task: ffff880071544240 task.stack: ffffc90000c28000
[ 46.417061] RIP: 0010:read_page+0x1dd/0x1e0 [md_mod]
[ 46.417062] RSP: 0000:ffffc90000c2bbc0 EFLAGS: 00010246
[ 46.417064] RAX: 000fffffc0000000 RBX: 0000000000000000 RCX:
0000000000000350
[ 46.417065] RDX: ffff88006e88b000 RSI: 0000000000000000 RDI:
ffff88006e0aea00
[ 46.417066] RBP: ffffc90000c2bc20 R08: ffffea0001c80e80 R09:
00000000000554a0
[ 46.417068] R10: 0000000000000010 R11: 000000007203a000 R12:
ffff88006e88b000
[ 46.417069] R13: ffff88006e88b000 R14: 0000000000000350 R15:
ffff8800711f6610
[ 46.417071] FS: 00007f666fc9f700(0000) GS:ffff88007fd00000(0000)
knlGS:0000000000000000
[ 46.417073] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 46.417074] CR2: 0000000000446710 CR3: 0000000071e3e000 CR4:
00000000000406e0
[ 46.417081] Call Trace:
[ 46.417088] bitmap_create+0x264/0x990 [md_mod]
[ 46.417091] ? raid1_run+0x1d0/0x2e0 [raid1]
[ 46.417096] md_run+0x5d2/0xb00 [md_mod]
[ 46.417100] ? locks_dispose_list+0x36/0x50
[ 46.417102] ? flock_lock_inode+0x124/0x280
[ 46.417107] do_md_run+0x14/0xb0 [md_mod]
[ 46.417111] md_ioctl+0x13ed/0x1830 [md_mod]
[ 46.417114] ? kzfree+0x2d/0x30
[ 46.417119] blkdev_ioctl+0x475/0x8b0
[ 46.417121] ? mntput+0x24/0x40
[ 46.417125] block_ioctl+0x41/0x50
[ 46.417127] do_vfs_ioctl+0x96/0x5b0
[ 46.417130] ? ____fput+0xe/0x10
[ 46.417133] ? task_work_run+0x88/0xb0
[ 46.417135] SyS_ioctl+0x79/0x90
[ 46.417138] entry_SYSCALL_64_fastpath+0x1a/0xa5
[ 46.417140] RIP: 0033:0x7f666f5d84b7
[ 46.417141] RSP: 002b:00007ffd3df6a228 EFLAGS: 00000246 ORIG_RAX:
0000000000000010
[ 46.417143] RAX: ffffffffffffffda RBX: 00000000018e6700 RCX:
00007f666f5d84b7
[ 46.417144] RDX: 00007ffd3df6a540 RSI: 00000000400c0930 RDI:
0000000000000004
[ 46.417145] RBP: 0000000000000000 R08: 0000000000001000 R09:
00007f666f893678
[ 46.417146] R10: 0000000000000000 R11: 0000000000000246 R12:
0000000000000000
[ 46.417148] R13: 0000000000000004 R14: 00007ffd3df6a720 R15:
00000000018e6640
[ 46.417149] Code: ff ff 48 8b 55 a0 89 d9 be 00 10 00 00 48 c7 c7 c8
4d 4a a0 31 c0 48 c1 e2 0c e8 62 24 c4 e0 e9 59 ff ff ff bb fb ff ff ff
eb d7 <0f> 0b 90 66 66 66 66 90 55 48 89 e5 41 57 4c 8d 7f 18 41 56 45
[ 46.417176] RIP: read_page+0x1dd/0x1e0 [md_mod] RSP: ffffc90000c2bbc0
[ 46.417178] ---[ end trace 0c4d19ffd8ced9b8 ]---
Thanks,
-Zhilong
Thanks,
NeilBrown
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 40f3cd7eab0f..52fe93fa4598 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -368,12 +368,7 @@ static int read_page(struct file *file, unsigned long index,
pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
(unsigned long long)index << PAGE_SHIFT);
- bh = alloc_page_buffers(page, 1<<inode->i_blkbits, 0);
- if (!bh) {
- ret = -ENOMEM;
- goto out;
- }
- attach_page_buffers(page, bh);
+ bh = page_buffers(page);
block = index << (PAGE_SHIFT - inode->i_blkbits);
while (bh) {
if (count == 0)
@@ -771,12 +766,18 @@ static inline struct page *filemap_get_page(struct bitmap_storage *store,
}
static int bitmap_storage_alloc(struct bitmap_storage *store,
- unsigned long chunks, int with_super,
+ unsigned long chunks,
+ struct file *file,
+ int with_super,
int slot_number)
{
int pnum, offset = 0;
unsigned long num_pages;
unsigned long bytes;
+ struct inode *inode = NULL;
+
+ if (file)
+ inode = file_inode(file);
bytes = DIV_ROUND_UP(chunks, 8);
if (with_super)
@@ -804,12 +805,21 @@ static int bitmap_storage_alloc(struct bitmap_storage *store,
}
for ( ; pnum < num_pages; pnum++) {
- store->filemap[pnum] = alloc_page(GFP_KERNEL|__GFP_ZERO);
- if (!store->filemap[pnum]) {
+ struct page *p = alloc_page(GFP_KERNEL|__GFP_ZERO);
+ store->filemap[pnum] = p;
+ if (!p) {
store->file_pages = pnum;
return -ENOMEM;
}
- store->filemap[pnum]->index = pnum + offset;
+ if (inode) {
+ struct buffer_head *bh;
+ bh = alloc_page_buffers(p, 1 << inode->i_blkbits, 0);
+ if (bh)
+ attach_page_buffers(p, bh);
+ else
+ return -ENOMEM;
+ }
+ p->index = pnum + offset;
}
store->file_pages = pnum;
@@ -2091,7 +2101,7 @@ int bitmap_resize(struct bitmap *bitmap, sector_t blocks,
chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
memset(&store, 0, sizeof(store));
if (bitmap->mddev->bitmap_info.offset || bitmap->mddev->bitmap_info.file)
- ret = bitmap_storage_alloc(&store, chunks,
+ ret = bitmap_storage_alloc(&store, chunks, bitmap->mddev->bitmap_info.file,
!bitmap->mddev->bitmap_info.external,
mddev_is_clustered(bitmap->mddev)
? bitmap->cluster_slot : 0);
--
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