Go to file
David Jeffery e1b4a622ee block: recalculate segment count for multi-segment discards correctly
[ Upstream commit a958937ff166fc60d1c3a721036f6ff41bfa2821 ]

When a stacked block device inserts a request into another block device
using blk_insert_cloned_request, the request's nr_phys_segments field gets
recalculated by a call to blk_recalc_rq_segments in
blk_cloned_rq_check_limits. But blk_recalc_rq_segments does not know how to
handle multi-segment discards. For disk types which can handle
multi-segment discards like nvme, this results in discard requests which
claim a single segment when it should report several, triggering a warning
in nvme and causing nvme to fail the discard from the invalid state.

 WARNING: CPU: 5 PID: 191 at drivers/nvme/host/core.c:700 nvme_setup_discard+0x170/0x1e0 [nvme_core]
 ...
 nvme_setup_cmd+0x217/0x270 [nvme_core]
 nvme_loop_queue_rq+0x51/0x1b0 [nvme_loop]
 __blk_mq_try_issue_directly+0xe7/0x1b0
 blk_mq_request_issue_directly+0x41/0x70
 ? blk_account_io_start+0x40/0x50
 dm_mq_queue_rq+0x200/0x3e0
 blk_mq_dispatch_rq_list+0x10a/0x7d0
 ? __sbitmap_queue_get+0x25/0x90
 ? elv_rb_del+0x1f/0x30
 ? deadline_remove_request+0x55/0xb0
 ? dd_dispatch_request+0x181/0x210
 __blk_mq_do_dispatch_sched+0x144/0x290
 ? bio_attempt_discard_merge+0x134/0x1f0
 __blk_mq_sched_dispatch_requests+0x129/0x180
 blk_mq_sched_dispatch_requests+0x30/0x60
 __blk_mq_run_hw_queue+0x47/0xe0
 __blk_mq_delay_run_hw_queue+0x15b/0x170
 blk_mq_sched_insert_requests+0x68/0xe0
 blk_mq_flush_plug_list+0xf0/0x170
 blk_finish_plug+0x36/0x50
 xlog_cil_committed+0x19f/0x290 [xfs]
 xlog_cil_process_committed+0x57/0x80 [xfs]
 xlog_state_do_callback+0x1e0/0x2a0 [xfs]
 xlog_ioend_work+0x2f/0x80 [xfs]
 process_one_work+0x1b6/0x350
 worker_thread+0x53/0x3e0
 ? process_one_work+0x350/0x350
 kthread+0x11b/0x140
 ? __kthread_bind_mask+0x60/0x60
 ret_from_fork+0x22/0x30

This patch fixes blk_recalc_rq_segments to be aware of devices which can
have multi-segment discards. It calculates the correct discard segment
count by counting the number of bio as each discard bio is considered its
own segment.

Fixes: 1e739730c5b9 ("block: optionally merge discontiguous discard bios into a single request")
Signed-off-by: David Jeffery <djeffery@redhat.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Link: https://lore.kernel.org/r/20210211143807.GA115624@redhat
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-12 12:53:31 +08:00
Documentation KVM: arm64: Reject VM creation when the default IPA size is unsupported 2021-04-12 12:53:12 +08:00
LICENSES Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
arch arm64: kdump: update ppos when reading elfcorehdr 2021-04-12 12:53:30 +08:00
block block: recalculate segment count for multi-segment discards correctly 2021-04-12 12:53:31 +08:00
certs certs: Fix blacklist flag type confusion 2021-04-12 12:52:25 +08:00
crypto crypto: x86 - Regularize glue function prototypes 2021-04-12 12:53:14 +08:00
drivers ACPI: scan: Use unique number for instance_no 2021-04-12 12:53:31 +08:00
fs squashfs: fix xattr id and id lookup sanity checks 2021-04-12 12:53:25 +08:00
include ACPI: scan: Use unique number for instance_no 2021-04-12 12:53:31 +08:00
init fgraph: Initialize tracing_graph_pause at task creation 2021-04-12 12:51:55 +08:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2021-03-16 16:27:51 +08:00
kernel PM: EM: postpone creating the debugfs dir till fs_initcall 2021-04-12 12:53:30 +08:00
lib PCI: Fix pci_register_io_range() memory leak 2021-04-12 12:53:04 +08:00
mm hugetlbfs: hugetlb_fault_mutex_hash() cleanup 2021-04-12 12:53:21 +08:00
net Revert "netfilter: x_tables: Update remaining dereference to RCU" 2021-04-12 12:53:31 +08:00
package generate-rpms: modify the name of the kernel tag for x86 and arm64 2021-04-07 06:53:59 +00:00
samples samples, bpf: Add missing munmap in xdpsock 2021-04-12 12:52:57 +08:00
scripts ftrace: Have recordmcount use w8 to read relp->r_info in arm64_is_fake_mcount 2021-04-12 12:52:52 +08:00
security integrity: double check iint_cache was initialized 2021-04-12 12:53:26 +08:00
sound ALSA: hda: ignore invalid NHLT table 2021-04-12 12:53:22 +08:00
tools perf auxtrace: Fix auxtrace queue conflict 2021-04-12 12:53:31 +08:00
usr Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
virt KVM: arm64: Ensure I-cache isolation between vcpus of a same VM 2021-04-12 12:53:12 +08:00
.clang-format Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
.cocciconfig Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
.get_maintainer.ignore Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
.gitattributes Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
.gitignore Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
COPYING Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
CREDITS Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
Kbuild Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
Kconfig Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
MAINTAINERS Documentation/llvm: add documentation on building w/ Clang/LLVM 2021-03-16 16:34:24 +08:00
Makefile kbuild: Fix <linux/version.h> for empty SUBLEVEL or PATCHLEVEL again 2021-04-12 12:53:18 +08:00
README Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
README.md Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
backport_remove_lists.txt Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
tools_key.pub Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00

README.md

Tencent Linux Kernel 4.0