Commit:
f4b07fd62d ("perf/core: Use POLLHUP for pinned events in error")
started to emit POLLHUP for pinned events in an error state.
But the POLLHUP is also used to signal events that the attached task is
terminated. To distinguish pinned per-task events in the error state
it would need to check if the task is live.
Change it to POLLERR to make it clear.
Suggested-by: Gabriel Marin <gmx@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250422223318.180343-1-namhyung@kernel.org
objtool already struggles to identify jump tables correctly in non-PIC
code, where the idiom is something like
jmpq *table(,%idx,8)
and the table is a list of absolute addresses of jump targets.
When using -fPIC, both the table reference as well as the jump targets
are emitted in a RIP-relative manner, resulting in something like
leaq table(%rip), %tbl
movslq (%tbl,%idx,4), %offset
addq %offset, %tbl
jmpq *%tbl
and the table is a list of offsets of the jump targets relative to the
start of the entire table.
Considering that this sequence of instructions can be interleaved with
other instructions that have nothing to do with the jump table in
question, it is extremely difficult to infer the control flow by
deriving the jump targets from the indirect jump, the location of the
table and the relative offsets it contains.
So let's not bother and disable jump tables for code built with -fPIC
under arch/x86/boot/startup.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20250422210510.600354-2-ardb+git@google.com
This version of the hardware moved around a bunch of registers, so we
avoid the old compatible for these and introduce register offset
structures to handle the differences.
Signed-off-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Link: https://patch.msgid.link/20250401091713.2765724-14-maz@kernel.org
Newer versions of the Apple PCIe block have a bunch of small, but
annoying differences.
In order to embrace this diversity of implementations, move the
currently hardcoded offsets into a hw_info structure. Future SoCs
will provide their own structure describing the applicable offsets.
Signed-off-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
[maz: split from original patch to only address T8103]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Link: https://patch.msgid.link/20250401091713.2765724-13-maz@kernel.org
This is checking a core refclk in per-port setup which doesn't make a
lot of sense, and the bootloader needs to have gone through this anyway.
It doesn't work on T602x, so just drop it across the board.
Signed-off-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Link: https://patch.msgid.link/20250401091713.2765724-11-maz@kernel.org
T602x PCIe cores move these registers around. Instead of hardcoding in
another offset, let's move them into their own reg entries. This matches
what Apple does on macOS device trees too.
Maintains backwards compatibility with old DTs by using the old offsets.
Note that we open code devm_platform_ioremap_resource_byname() to avoid
error messages on older platforms with missing resources in the pcie
node. ("pcie-apple 590000000.pcie: invalid resource (null)" on probe)
Co-developed-by: Janne Grunau <j@jannau.net>
Signed-off-by: Janne Grunau <j@jannau.net>
Signed-off-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Link: https://patch.msgid.link/20250401091713.2765724-10-maz@kernel.org
In the success path, we hang onto a reference to the node, so make sure
to grab one. The caller iterator puts our borrowed reference when we
return.
Signed-off-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Link: https://patch.msgid.link/20250401091713.2765724-9-maz@kernel.org
T602x seems to have dropped the rather useful SET/CLR accessors
to the masking register.
Instead, let's use the mask register directly, and wrap it with
a brand new spinlock. No, this isn't moving in the right direction.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Link: https://patch.msgid.link/20250401091713.2765724-8-maz@kernel.org
As we move towards supporting SoCs with varying RID-to-SID mapping
capabilities, turn the static SID tracking bitmap into a dynamically
allocated one. The current allocation size is still the same, but
that's about to change.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Link: https://patch.msgid.link/20250401091713.2765724-7-maz@kernel.org
Now that we have the required infrastructure, split the Apple PCIe
setup into two categories:
- stuff that has to do with PCI setup stays in the .init() callback
- stuff that is just driver gunk (such as MSI setup) goes into a
probe routine, which will eventually call into the host-common
code
The result is a far more logical setup process.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Link: https://patch.msgid.link/20250401091713.2765724-6-maz@kernel.org
In order to decouple ecam config space creation from probing via
pci_host_common_probe(), allow the private pointer to be populated
via the device drvdata pointer.
Crucially, this is set before calling ops->init(), allowing that
particular callback to have access to probe data.
This should have no impact on existing code which ignores the
current value of cfg->priv.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Link: https://patch.msgid.link/20250401091713.2765724-5-maz@kernel.org
pci_host_common_probe() is an extremely useful helper, as it
abstracts away most of the gunk that a "mostly-ECAM-compliant"
device driver needs.
However, it is structured as a probe function, meaning that a lot
of the driver-specific setup has to happen in a .init() callback,
after the bridge and config space have been instantiated.
This is a bit awkward, and results in a number of convolutions
that could be avoided if the host-common code was more like
a library.
Introduce a pci_host_common_init() helper that does exactly that,
taking the platform device and a struct pci_ecam_op as parameters.
This can then be called from the probe routine, and a lot of the
code that isn't relevant to PCI setup moved away from the .init()
callback. This also removes the dependency on the device match
data, which is an oddity.
Signed-off-by: Marc Zyngier <maz@kernel.org>
[mani: fixed spelling mistakes]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Link: https://patch.msgid.link/20250401091713.2765724-4-maz@kernel.org
Add IPQ5018 platform with is based on Qcom IP rev. 2.9.0 and Synopsys IP
rev. 5.00a.
The platform itself has two PCIe Gen2 controllers: one single-lane and
one dual-lane. So add the IPQ5018 compatible and re-use 2_9_0 ops.
Signed-off-by: Nitheesh Sekar <quic_nsekar@quicinc.com>
Signed-off-by: Sricharan R <quic_srichara@quicinc.com>
Signed-off-by: George Moussalem <george.moussalem@outlook.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://patch.msgid.link/20250326-ipq5018-pcie-v7-4-e1828fef06c9@outlook.com
Add support for the PCIe controller on the Qualcomm
IPQ5108 SoC to the bindings.
Signed-off-by: Nitheesh Sekar <quic_nsekar@quicinc.com>
Signed-off-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
Signed-off-by: George Moussalem <george.moussalem@outlook.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://patch.msgid.link/20250326-ipq5018-pcie-v7-3-e1828fef06c9@outlook.com
PCIe equalization presets are predefined settings used to optimize signal
integrity by compensating for signal loss and distortion in high-speed data
transmission.
Based upon the number of lanes and the data rate supported, write the
preset data read from the device tree in to the lane equalization control
registers. These preset values will be used by the controller during the
LTSSM lane equalization procedure.
Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
[mani: reworded the commit message and comments in the driver]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://patch.msgid.link/20250328-preset_v6-v9-5-22cfa0490518@oss.qualcomm.com
The content in these files has been moved to the schemas in dtschema.
pci.txt is covered by pci-bus-common.yaml and pci-host-bridge.yaml.
pci-iommu.txt is covered by pci-iommu.yaml. pci-msi.txt is covered in
msi-map property in pci-host-bridge.yaml.
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Cc: Frank Li <Frank.li@nxp.com>
Link: https://patch.msgid.link/20250404221559.552201-1-robh@kernel.org
Convert the marvell,armada8k-pcie binding to DT schema. The binding
uses different names for reg, clocks, and phys which have to be added
to the common Synopsys DWC binding.
The "marvell,reset-gpio" property was not documented. Mark it deprecated
as the "reset-gpios" property can be used instead. The "msi-parent"
property was also not documented.
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://patch.msgid.link/20250414214135.1680076-1-robh@kernel.org
Convert the Marvell EBU (Kirkwood, Dove, Armada XP/370) to DT schema
format. Add "error" to interrupt-names which is in use, but missing.
Shorten the example from 10 child nodes to 6 as the additional ones
don't add much value to the example.
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://patch.msgid.link/20250414214157.1680484-1-robh@kernel.org
Coding style and common logic dictates that headers should not be
included in device nodes. No functional impact.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20250324125202.81986-2-krzysztof.kozlowski@linaro.org
DTS example in the bindings should be indented with 2- or 4-spaces and
aligned with opening '- |', so correct any differences like 3-spaces or
mixtures 2- and 4-spaces in one binding.
No functional changes here, but saves some comments during reviews of
new patches built on existing code.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20250324125202.81986-1-krzysztof.kozlowski@linaro.org
rk3562 is using the same dwc controller as rk3576.
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20250415051855.59740-2-kever.yang@rock-chips.com
rk3576 is using DWC PCIe controller, with msi interrupt directly to GIC
instead of using GIC ITS, so
- no ITS support is required and the 'msi-map' is not required,
- a new 'msi' interrupt is needed.
Co-developed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
[mani: changed 'its' to 'ITS' in the binding, spelling mistake fix]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/20250414145110.11275-2-kever.yang@rock-chips.com
If the call to pci_host_probe() in cdns_pcie_host_setup() fails, PM
runtime count is decremented in the error path using pm_runtime_put_sync().
But the runtime count is not incremented by this driver, but only by the
callers (cdns_plat_pcie_probe/j721e_pcie_probe). And the callers also
decrement the runtime PM count in their error path. So this leads to the
below warning from the PM core:
"runtime PM usage count underflow!"
So fix it by getting rid of pm_runtime_put_sync() in the error path and
directly return the errno.
Fixes: 49e427e6bd ("Merge branch 'pci/host-probe-refactor'")
Signed-off-by: Hans Zhang <18255117159@163.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://patch.msgid.link/20250419133058.162048-1-18255117159@163.com
When running machines with 64k page size and a 16k nodesize we started
seeing tree log corruption in production. This turned out to be because
we were not writing out dirty blocks sometimes, so this in fact affects
all metadata writes.
When writing out a subpage EB we scan the subpage bitmap for a dirty
range. If the range isn't dirty we do
bit_start++;
to move onto the next bit. The problem is the bitmap is based on the
number of sectors that an EB has. So in this case, we have a 64k
pagesize, 16k nodesize, but a 4k sectorsize. This means our bitmap is 4
bits for every node. With a 64k page size we end up with 4 nodes per
page.
To make this easier this is how everything looks
[0 16k 32k 48k ] logical address
[0 4 8 12 ] radix tree offset
[ 64k page ] folio
[ 16k eb ][ 16k eb ][ 16k eb ][ 16k eb ] extent buffers
[ | | | | | | | | | | | | | | | | ] bitmap
Now we use all of our addressing based on fs_info->sectorsize_bits, so
as you can see the above our 16k eb->start turns into radix entry 4.
When we find a dirty range for our eb, we correctly do bit_start +=
sectors_per_node, because if we start at bit 0, the next bit for the
next eb is 4, to correspond to eb->start 16k.
However if our range is clean, we will do bit_start++, which will now
put us offset from our radix tree entries.
In our case, assume that the first time we check the bitmap the block is
not dirty, we increment bit_start so now it == 1, and then we loop
around and check again. This time it is dirty, and we go to find that
start using the following equation
start = folio_start + bit_start * fs_info->sectorsize;
so in the case above, eb->start 0 is now dirty, and we calculate start
as
0 + 1 * fs_info->sectorsize = 4096
4096 >> 12 = 1
Now we're looking up the radix tree for 1, and we won't find an eb.
What's worse is now we're using bit_start == 1, so we do bit_start +=
sectors_per_node, which is now 5. If that eb is dirty we will run into
the same thing, we will look at an offset that is not populated in the
radix tree, and now we're skipping the writeout of dirty extent buffers.
The best fix for this is to not use sectorsize_bits to address nodes,
but that's a larger change. Since this is a fs corruption problem fix
it simply by always using sectors_per_node to increment the start bit.
Fixes: c4aec299fa ("btrfs: introduce submit_eb_subpage() to submit a subpage metadata page")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
There is a bug report that a syzbot reproducer can lead to the following
busy inode at unmount time:
BTRFS info (device loop1): last unmount of filesystem 1680000e-3c1e-4c46-84b6-56bd3909af50
VFS: Busy inodes after unmount of loop1 (btrfs)
------------[ cut here ]------------
kernel BUG at fs/super.c:650!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 48168 Comm: syz-executor Not tainted 6.15.0-rc2-00471-g119009db2674 #2 PREEMPT(full)
Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:generic_shutdown_super+0x2e9/0x390 fs/super.c:650
Call Trace:
<TASK>
kill_anon_super+0x3a/0x60 fs/super.c:1237
btrfs_kill_super+0x3b/0x50 fs/btrfs/super.c:2099
deactivate_locked_super+0xbe/0x1a0 fs/super.c:473
deactivate_super fs/super.c:506 [inline]
deactivate_super+0xe2/0x100 fs/super.c:502
cleanup_mnt+0x21f/0x440 fs/namespace.c:1435
task_work_run+0x14d/0x240 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x269/0x290 kernel/entry/common.c:218
do_syscall_64+0xd4/0x250 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
[CAUSE]
When btrfs_alloc_path() failed, btrfs_iget() directly returned without
releasing the inode already allocated by btrfs_iget_locked().
This results the above busy inode and trigger the kernel BUG.
[FIX]
Fix it by calling iget_failed() if btrfs_alloc_path() failed.
If we hit error inside btrfs_read_locked_inode(), it will properly call
iget_failed(), so nothing to worry about.
Although the iget_failed() cleanup inside btrfs_read_locked_inode() is a
break of the normal error handling scheme, let's fix the obvious bug
and backport first, then rework the error handling later.
Reported-by: Penglei Jiang <superman.xpt@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/20250421102425.44431-1-superman.xpt@gmail.com/
Fixes: 7c855e16ab ("btrfs: remove conditional path allocation in btrfs_read_locked_inode()")
CC: stable@vger.kernel.org # 6.13+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Penglei Jiang <superman.xpt@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In run_delalloc_nocow(), when the found btrfs_key's offset > cur_offset,
it indicates a gap between the current processing region and
the next file extent. The original code would directly jump to
the "must_cow" label, which increments the slot and forces a fallback
to COW. This behavior might skip an extent item and result in an
overestimated COW fallback range.
This patch modifies the logic so that when a gap is detected:
- If no COW range is already being recorded (cow_start is unset),
cow_start is set to cur_offset.
- cur_offset is then advanced to the beginning of the next extent.
- Instead of jumping to "must_cow", control flows directly to
"next_slot" so that the same extent item can be reexamined properly.
The change ensures that we accurately account for the extent gap and
avoid accidentally extending the range that needs to fallback to COW.
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Dave Chen <davechen@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Normally do_lock_mount(path, _) is locking a mountpoint pinned by
*path and at the time when matching unlock_mount() unlocks that
location it is still pinned by the same thing.
Unfortunately, for 'beneath' case it's no longer that simple -
the object being locked is not the one *path points to. It's the
mountpoint of path->mnt. The thing is, without sufficient locking
->mnt_parent may change under us and none of the locks are held
at that point. The rules are
* mount_lock stabilizes m->mnt_parent for any mount m.
* namespace_sem stabilizes m->mnt_parent, provided that
m is mounted.
* if either of the above holds and refcount of m is positive,
we are guaranteed the same for refcount of m->mnt_parent.
namespace_sem nests inside inode_lock(), so do_lock_mount() has
to take inode_lock() before grabbing namespace_sem. It does
recheck that path->mnt is still mounted in the same place after
getting namespace_sem, and it does take care to pin the dentry.
It is needed, since otherwise we might end up with racing mount --move
(or umount) happening while we were getting locks; in that case
dentry would no longer be a mountpoint and could've been evicted
on memory pressure along with its inode - not something you want
when grabbing lock on that inode.
However, pinning a dentry is not enough - the matching mount is
also pinned only by the fact that path->mnt is mounted on top it
and at that point we are not holding any locks whatsoever, so
the same kind of races could end up with all references to
that mount gone just as we are about to enter inode_lock().
If that happens, we are left with filesystem being shut down while
we are holding a dentry reference on it; results are not pretty.
What we need to do is grab both dentry and mount at the same time;
that makes inode_lock() safe *and* avoids the problem with fs getting
shut down under us. After taking namespace_sem we verify that
path->mnt is still mounted (which stabilizes its ->mnt_parent) and
check that it's still mounted at the same place. From that point
on to the matching namespace_unlock() we are guaranteed that
mount/dentry pair we'd grabbed are also pinned by being the mountpoint
of path->mnt, so we can quietly drop both the dentry reference (as
the current code does) and mnt one - it's OK to do under namespace_sem,
since we are not dropping the final refs.
That solves the problem on do_lock_mount() side; unlock_mount()
also has one, since dentry is guaranteed to stay pinned only until
the namespace_unlock(). That's easy to fix - just have inode_unlock()
done earlier, while it's still pinned by mp->m_dentry.
Fixes: 6ac3928156 "fs: allow to mount beneath top mount" # v6.5+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Now that all sha1_base users have been converted to use the API
partial block handling, remove the partial block helpers.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
