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  1. 09 May, 2024 6 commits
  3. 07 May, 2024 8 commits
  5. 06 May, 2024 1 commit
  7. 03 May, 2024 4 commits
    • INAGAKI Hiroshi's avatar
      block: fix and simplify blkdevparts= cmdline parsing · bc2e07df
      INAGAKI Hiroshi authored 
      Fix the cmdline parsing of the "blkdevparts=" parameter using strsep(),
which makes the code simpler.

Before commit 146afeb2 ("block: use strscpy() to instead of
strncpy()"), we used a strncpy() to copy a block device name and partition
names. The commit simply replaced a strncpy() and NULL termination with
a strscpy(). It did not update calculations of length passed to strscpy().
While the length passed to strncpy() is just a length of valid characters
without NULL termination ('\0'), strscpy() takes it as a length of the
destination buffer, including a NULL termination.

Since the source buffer is not necessarily NULL terminated, the current
code copies "length - 1" characters and puts a NULL character in the
destination buffer. It replaces the last character with NULL and breaks
the parsing.

As an example, that buffer will be passed to parse_parts() and breaks
parsing sub-partitions due to the missing ')' at the end, like the
following.

example (Check Point V-80 & OpenWrt):

- Linux Kernel 6.6

  [    0.000000] Kernel command line: console=ttyS0,115200 earlycon=uart8250,mmio32,0xf0512000 crashkernel=30M mvpp2x.queue_mode=1 blkdevparts=mmcblk1:48M@10M(kernel-1),1M(dtb-1),720M(rootfs-1),48M(kernel-2),1M(dtb-2),720M(rootfs-2),300M(default_sw),650M(logs),1M(preset_cfg),1M(adsl),-(storage) maxcpus=4
  ...
  [    0.884016] mmc1: new HS200 MMC card at address 0001
  [    0.889951] mmcblk1: mmc1:0001 004GA0 3.69 GiB
  [    0.895043] cmdline partition format is invalid.
  [    0.895704]  mmcblk1: p1
  [    0.903447] mmcblk1boot0: mmc1:0001 004GA0 2.00 MiB
  [    0.908667] mmcblk1boot1: mmc1:0001 004GA0 2.00 MiB
  [    0.913765] mmcblk1rpmb: mmc1:0001 004GA0 512 KiB, chardev (248:0)

  1. "48M@10M(kernel-1),..." is passed to strscpy() with length=17
     from parse_parts()
  2. strscpy() returns -E2BIG and the destination buffer has
     "48M@10M(kernel-1\0"
  3. "48M@10M(kernel-1\0" is passed to parse_subpart()
  4. parse_subpart() fails to find ')' when parsing a partition name,
     and returns error

- Linux Kernel 6.1

  [    0.000000] Kernel command line: console=ttyS0,115200 earlycon=uart8250,mmio32,0xf0512000 crashkernel=30M mvpp2x.queue_mode=1 blkdevparts=mmcblk1:48M@10M(kernel-1),1M(dtb-1),720M(rootfs-1),48M(kernel-2),1M(dtb-2),720M(rootfs-2),300M(default_sw),650M(logs),1M(preset_cfg),1M(adsl),-(storage) maxcpus=4
  ...
  [    0.953142] mmc1: new HS200 MMC card at address 0001
  [    0.959114] mmcblk1: mmc1:0001 004GA0 3.69 GiB
  [    0.964259]  mmcblk1: p1(kernel-1) p2(dtb-1) p3(rootfs-1) p4(kernel-2) p5(dtb-2) 6(rootfs-2) p7(default_sw) p8(logs) p9(preset_cfg) p10(adsl) p11(storage)
  [    0.979174] mmcblk1boot0: mmc1:0001 004GA0 2.00 MiB
  [    0.984674] mmcblk1boot1: mmc1:0001 004GA0 2.00 MiB
  [    0.989926] mmcblk1rpmb: mmc1:0001 004GA0 512 KiB, chardev (248:0

By the way, strscpy() takes a length of destination buffer and it is
often confusing when copying characters with a specified length. Using
strsep() helps to separate the string by the specified character. Then,
we can use strscpy() naturally with the size of the destination buffer.

Separating the string on the fly is also useful to omit the redundant
string copy, reducing memory usage and improve the code readability.

Fixes: 146afeb2 ("block: use strscpy() to instead of strncpy()")
Suggested-by: default avatarNaohiro Aota <naota@elisp.net>
Signed-off-by: default avatarINAGAKI Hiroshi <musashino.open@gmail.com>
Reviewed-by: default avatarDaniel Golle <daniel@makrotopia.org>
Link: https://lore.kernel.org/r/20240421074005.565-1-musashino.open@gmail.comSigned-off-by: default avatarJens Axboe <axboe@kernel.dk>
      bc2e07df
    • Christoph Hellwig's avatar
      block: refine the EOF check in blkdev_iomap_begin · 0c12028a
      Christoph Hellwig authored 
      blkdev_iomap_begin rounds down the offset to the logical block size
before stashing it in iomap->offset and checking that it still is
inside the inode size.

Check the i_size check to the raw pos value so that we don't try a
zero size write if iter->pos is unaligned.

Fixes: 487c607d ("block: use iomap for writes to block devices")
Reported-by: syzbot+0a3683a0a6fecf909244@syzkaller.appspotmail.com
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Tested-by: syzbot+0a3683a0a6fecf909244@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20240503081042.2078062-1-hch@lst.deSigned-off-by: default avatarJens Axboe <axboe@kernel.dk>
      0c12028a
    • Christoph Hellwig's avatar
      block: add a partscan sysfs attribute for disks · a4217c67
      Christoph Hellwig authored 
      Userspace had been unknowingly relying on a non-stable interface of
kernel internals to determine if partition scanning is enabled for a
given disk. Provide a stable interface for this purpose instead.

Cc: stable@vger.kernel.org # 6.3+
Depends-on: 140ce28d ("block: add a disk_has_partscan helper")
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/linux-block/ZhQJf8mzq_wipkBH@gardel-login/
Link: https://lore.kernel.org/r/20240502130033.1958492-3-hch@lst.de
[axboe: add links and commit message from Keith]
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      a4217c67
    • Christoph Hellwig's avatar
      block: add a disk_has_partscan helper · 140ce28d
      Christoph Hellwig authored 
      Add a helper to check if partition scanning is enabled instead of
open coding the check in a few places.  This now always checks for
the hidden flag even if all but one of the callers are never reachable
for hidden gendisks.
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240502130033.1958492-2-hch@lst.deSigned-off-by: default avatarJens Axboe <axboe@kernel.dk>
      140ce28d
  9. 02 May, 2024 2 commits
  11. 01 May, 2024 14 commits
  13. 26 Apr, 2024 1 commit
  15. 25 Apr, 2024 3 commits
  17. 23 Apr, 2024 1 commit
    • Damien Le Moal's avatar
      block: use a per disk workqueue for zone write plugging · a8f59e5a
      Damien Le Moal authored 
      A zone write plug BIO work function blk_zone_wplug_bio_work() calls
submit_bio_noacct_nocheck() to execute the next unplugged BIO. This
function may block. So executing zone plugs BIO works using the block
layer global kblockd workqueue can potentially lead to preformance or
latency issues as the number of concurrent work for a workqueue is
limited to WQ_DFL_ACTIVE (256).
1) For a system with a large number of zoned disks, issuing write
   requests to otherwise unused zones may be delayed wiating for a work
   thread to become available.
2) Requeue operations which use kblockd but are independent of zone
   write plugging may alsoi end up being delayed.

To avoid these potential performance issues, create a workqueue per
zoned device to execute zone plugs BIO work. The workqueue max active
parameter is set to the maximum number of zone write plugs allocated
with the zone write plug mempool. This limit is equal to the maximum
number of open zones of the disk and defaults to 128 for disks that do
not have a limit on the number of open zones.

Fixes: dd291d77 ("block: Introduce zone write plugging")
Signed-off-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240420075811.1276893-3-dlemoal@kernel.orgSigned-off-by: default avatarJens Axboe <axboe@kernel.dk>
      a8f59e5a
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