Bitmap offset is allowed to be negative, indicating that bitmap precedes
metadata. Change the type back from sector_t to loff_t to satisfy
conditionals and calculations.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/linux-raid/CAPhsuW6HuaUJ5WcyPajVgUfkQFYp2D_cy1g6qxN4CU_gP2=z7g@mail.gmail.com/
Fixes: 10172f200b67 ("md: Fix types in sb writer")
Signed-off-by: Jonathan Derrick <jonathan.derrick@linux.dev>
Suggested-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230425011438.71046-1-jonathan.derrick@linux.dev
If the bitmap space has enough room, size the I/O for the last bitmap
page write to the optimal I/O size for the storage device. The expanded
write is checked that it won't overrun the data or metadata.
The drive this was tested against has higher latencies when there are
sub-4k writes due to device-side read-mod-writes of its atomic 4k write
unit. This change helps increase performance by sizing the last bitmap
page I/O for the device's preferred write unit, if it is given.
Example Intel/Solidigm P5520
Raid10, Chunk-size 64M, bitmap-size 57228 bits
$ mdadm --create /dev/md0 --level=10 --raid-devices=4 /dev/nvme{0,1,2,3}n1
--assume-clean --bitmap=internal --bitmap-chunk=64M
$ fio --name=test --direct=1 --filename=/dev/md0 --rw=randwrite --bs=4k --runtime=60
Without patch:
write: IOPS=1676, BW=6708KiB/s (6869kB/s)(393MiB/60001msec); 0 zone resets
With patch:
write: IOPS=15.7k, BW=61.4MiB/s (64.4MB/s)(3683MiB/60001msec); 0 zone resets
Biosnoop:
Without patch:
Time Process PID Device LBA Size Lat
1.410377 md0_raid10 6900 nvme0n1 W 16 4096 0.02
1.410387 md0_raid10 6900 nvme2n1 W 16 4096 0.02
1.410374 md0_raid10 6900 nvme3n1 W 16 4096 0.01
1.410381 md0_raid10 6900 nvme1n1 W 16 4096 0.02
1.410411 md0_raid10 6900 nvme1n1 W 115346512 4096 0.01
1.410418 md0_raid10 6900 nvme0n1 W 115346512 4096 0.02
1.410915 md0_raid10 6900 nvme2n1 W 24 3584 0.43 <--
1.410935 md0_raid10 6900 nvme3n1 W 24 3584 0.45 <--
1.411124 md0_raid10 6900 nvme1n1 W 24 3584 0.64 <--
1.411147 md0_raid10 6900 nvme0n1 W 24 3584 0.66 <--
1.411176 md0_raid10 6900 nvme3n1 W 2019022184 4096 0.01
1.411189 md0_raid10 6900 nvme2n1 W 2019022184 4096 0.02
With patch:
Time Process PID Device LBA Size Lat
5.747193 md0_raid10 727 nvme0n1 W 16 4096 0.01
5.747192 md0_raid10 727 nvme1n1 W 16 4096 0.02
5.747195 md0_raid10 727 nvme3n1 W 16 4096 0.01
5.747202 md0_raid10 727 nvme2n1 W 16 4096 0.02
5.747229 md0_raid10 727 nvme3n1 W 1196223704 4096 0.02
5.747224 md0_raid10 727 nvme0n1 W 1196223704 4096 0.01
5.747279 md0_raid10 727 nvme0n1 W 24 4096 0.01 <--
5.747279 md0_raid10 727 nvme1n1 W 24 4096 0.02 <--
5.747284 md0_raid10 727 nvme3n1 W 24 4096 0.02 <--
5.747291 md0_raid10 727 nvme2n1 W 24 4096 0.02 <--
5.747314 md0_raid10 727 nvme2n1 W 2234636712 4096 0.01
5.747317 md0_raid10 727 nvme1n1 W 2234636712 4096 0.02
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jon Derrick <jonathan.derrick@linux.dev>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230224183323.638-4-jonathan.derrick@linux.dev
Page->index is a pgoff_t and multiplying could cause overflows on a 32-bit architecture. In the sb writer, this is used to calculate and verify the sector being used, and is multiplied by a sector value. Using sector_t will cast it to a u64 type and is the more appropriate type for the unit. Additionally, the integer size unit is converted to a sector unit in later calculations, and is now corrected to be an unsigned type. Finally, clean up the calculations using variable aliases to improve readabiliy. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jon Derrick <jonathan.derrick@linux.dev> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230224183323.638-3-jonathan.derrick@linux.dev
Preparatory patch for optimal I/O size calculation. Move the sb writer loop routine into its own function for clarity. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jon Derrick <jonathan.derrick@linux.dev> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230224183323.638-2-jonathan.derrick@linux.dev
- limit bitmap chunk size internal u64 variable to values not overflowing the u32 bitmap superblock structure variable stored on persistent media - assign bitmap chunk size internal u64 variable from unsigned values to avoid possible sign extension artifacts when assigning from a s32 value The bug has been there since at least kernel 4.0. Steps to reproduce it: 1: mdadm -C /dev/mdx -l 1 --bitmap=internal --bitmap-chunk=256M -e 1.2 -n2 /dev/rnbd1 /dev/rnbd2 2 resize member device rnbd1 and rnbd2 to 8 TB 3 mdadm --grow /dev/mdx --size=max The bitmap_chunksize will overflow without patch. Cc: stable@vger.kernel.org Signed-off-by: Florian-Ewald Mueller <florian-ewald.mueller@ionos.com> Signed-off-by: Jack Wang <jinpu.wang@ionos.com> Signed-off-by: Song Liu <song@kernel.org>
Check the return value of md_bitmap_get_counter() in case it returns NULL pointer, which will result in a null pointer dereference. v2: update the check to include other dereference Signed-off-by: Li Zhong <floridsleeves@gmail.com> Signed-off-by: Song Liu <song@kernel.org>
Both submit_bh() and ll_rw_block() accept a request operation type and request flags as their first two arguments. Micro-optimize these two functions by combining these first two arguments into a single argument. This patch does not change the behavior of any of the modified code. Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jan Kara <jack@suse.cz> Acked-by: Song Liu <song@kernel.org> (for the md changes) Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-48-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Improve uniformity in the kernel of handling of request operation and flags by passing these as a single argument. Cc: Song Liu <song@kernel.org> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-32-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit includes two topics:
1> replace deprecated strlcpy
change strlcpy to strscpy for strlcpy is marked as deprecated in
Documentation/process/deprecated.rst
2> remove duplicated strlcpy line
in md_bitmap_read_sb@md-bitmap.c there are two duplicated strlcpy(), the
history:
- commit cf921cc19cf7 ("Add node recovery callbacks") introduced the first
usage of strlcpy().
- commit b97e92574c0b ("Use separate bitmaps for each nodes in the cluster")
introduced the second strlcpy(). this time, the two strlcpy() are same,
we can remove anyone safely.
- commit d3b178adb3a3 ("md: Skip cluster setup for dm-raid") added dm-raid
special handling. And the "nodes" value is the key of this patch. but
from this patch, strlcpy() which was introduced by b97e92574c0bf
become necessary.
- commit 3c462c880b52 ("md: Increment version for clustered bitmaps") used
clustered major version to only handle in clustered env. this patch
could look a polishment for clustered code logic.
So cf921cc19cf7 became useless after d3b178adb3a3a, we could remove it
safely.
Signed-off-by: Heming Zhao <heming.zhao@suse.com>
Signed-off-by: Song Liu <song@kernel.org>
If bitmap area contains invalid data, kernel will crash then mdadm triggers "Segmentation fault". This is cluster-md speical bug. In non-clustered env, mdadm will handle broken metadata case. In clustered array, only kernel space handles bitmap slot info. But even this bug only happened in clustered env, current sanity check is wrong, the code should be changed. How to trigger: (faulty injection) dd if=/dev/zero bs=1M count=1 oflag=direct of=/dev/sda dd if=/dev/zero bs=1M count=1 oflag=direct of=/dev/sdb mdadm -C /dev/md0 -b clustered -e 1.2 -n 2 -l mirror /dev/sda /dev/sdb mdadm -Ss echo aaa > magic.txt == below modifying slot 2 bitmap data == dd if=magic.txt of=/dev/sda seek=16384 bs=1 count=3 <== destroy magic dd if=/dev/zero of=/dev/sda seek=16436 bs=1 count=4 <== ZERO chunksize mdadm -A /dev/md0 /dev/sda /dev/sdb == kernel crashes. mdadm outputs "Segmentation fault" == Reason of kernel crash: In md_bitmap_read_sb (called by md_bitmap_create), bad bitmap magic didn't block chunksize assignment, and zero value made DIV_ROUND_UP_SECTOR_T() trigger "divide error". Crash log: kernel: md: md0 stopped. kernel: md/raid1:md0: not clean -- starting background reconstruction kernel: md/raid1:md0: active with 2 out of 2 mirrors kernel: dlm: ... ... kernel: md-cluster: Joined cluster 44810aba-38bb-e6b8-daca-bc97a0b254aa slot 1 kernel: md0: invalid bitmap file superblock: bad magic kernel: md_bitmap_copy_from_slot can't get bitmap from slot 2 kernel: md-cluster: Could not gather bitmaps from slot 2 kernel: divide error: 0000 [#1] SMP NOPTI kernel: CPU: 0 PID: 1603 Comm: mdadm Not tainted 5.14.6-1-default kernel: Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) kernel: RIP: 0010:md_bitmap_create+0x1d1/0x850 [md_mod] kernel: RSP: 0018:ffffc22ac0843ba0 EFLAGS: 00010246 kernel: ... ... kernel: Call Trace: kernel: ? dlm_lock_sync+0xd0/0xd0 [md_cluster 77fe..7a0] kernel: md_bitmap_copy_from_slot+0x2c/0x290 [md_mod 24ea..d3a] kernel: load_bitmaps+0xec/0x210 [md_cluster 77fe..7a0] kernel: md_bitmap_load+0x81/0x1e0 [md_mod 24ea..d3a] kernel: do_md_run+0x30/0x100 [md_mod 24ea..d3a] kernel: md_ioctl+0x1290/0x15a0 [md_mod 24ea....d3a] kernel: ? mddev_unlock+0xaa/0x130 [md_mod 24ea..d3a] kernel: ? blkdev_ioctl+0xb1/0x2b0 kernel: block_ioctl+0x3b/0x40 kernel: __x64_sys_ioctl+0x7f/0xb0 kernel: do_syscall_64+0x59/0x80 kernel: ? exit_to_user_mode_prepare+0x1ab/0x230 kernel: ? syscall_exit_to_user_mode+0x18/0x40 kernel: ? do_syscall_64+0x69/0x80 kernel: entry_SYSCALL_64_after_hwframe+0x44/0xae kernel: RIP: 0033:0x7f4a15fa722b kernel: ... ... kernel: ---[ end trace 8afa7612f559c868 ]--- kernel: RIP: 0010:md_bitmap_create+0x1d1/0x850 [md_mod] Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev> Signed-off-by: Heming Zhao <heming.zhao@suse.com> Signed-off-by: Song Liu <song@kernel.org>