TencentOS-kernel/include
Chunguang Xu 6becaf2948 block: Do not discard buffers under a mounted filesystem
commit: <384d87ef2c954fc58e6c5fd8253e4a1984f5fe02>

Discarding blocks and buffers under a mounted filesystem is hardly
anything admin wants to do. Usually it will confuse the filesystem and
sometimes the loss of buffer_head state (including b_private field) can
even cause crashes like:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
PGD 0 P4D 0
Oops: 0002 [#1] SMP PTI
Hardware name: Huawei RH2288H V3/BC11HGSA0, BIOS 1.57 08/11/2015
RIP: 0010:jbd2_journal_grab_journal_head+0x1b/0x40 [jbd2]
...
Call Trace:
 __jbd2_journal_insert_checkpoint+0x23/0x70 [jbd2]
 jbd2_journal_commit_transaction+0x155f/0x1b60 [jbd2]
 kjournald2+0xbd/0x270 [jbd2]

So if we don't have block device open with O_EXCL already, claim the
block device while we truncate buffer cache. This makes sure any
exclusive block device user (such as filesystem) cannot operate on the
device while we are discarding buffer cache.

Signed-off-by: Chunguang Xu <brookxu@tencent.com>
2022-11-03 16:14:08 +08:00
..
acpi ACPI: scan: Use unique number for instance_no 2021-04-12 12:53:31 +08:00
asm-generic bpf: Add BTF_ID_LIST/BTF_ID/BTF_ID_UNUSED macros 2022-08-30 11:33:27 +08:00
clocksource Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
crypto crypto: api - check for ERR pointers in crypto_destroy_tfm() 2021-05-20 16:07:23 +08:00
drm iommu/vt-d: Move intel_iommu_gfx_mapped to Intel IOMMU header 2021-03-16 16:41:21 +08:00
dt-bindings Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
keys KEYS: Don't write out to userspace while holding key semaphore 2021-03-16 16:26:42 +08:00
kvm Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
linux block: Do not discard buffers under a mounted filesystem 2022-11-03 16:14:08 +08:00
math-emu Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
media media: rc: compile rc-cec.c into rc-core 2021-04-12 12:53:01 +08:00
misc Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
net bpf: Allow any port in bpf_bind helper 2022-08-30 11:33:35 +08:00
pcmcia Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
ras Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
rdma RDMA/umem: Fix signature of stub ib_umem_find_best_pgsz() 2021-03-16 16:38:49 +08:00
scsi kabi: reserve space for kabi 2021-06-23 07:24:18 +00:00
soc irqchip/eznps: Fix build error for !ARC700 builds 2021-03-16 16:35:56 +08:00
sound ALSA: hda: intel-nhlt: verify config type 2021-04-12 12:52:52 +08:00
target scsi: target: core: Add cmd length set before cmd complete 2021-04-12 12:53:04 +08:00
trace writeback: Drop I_DIRTY_TIME_EXPIRE 2021-04-12 12:51:42 +08:00
uapi bpf: Allow for map-in-map with dynamic inner array map entries 2022-08-30 11:33:35 +08:00
vdso Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
video Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
xen Xen/gntdev: correct error checking in gntdev_map_grant_pages() 2021-04-12 12:52:07 +08:00