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FAILED: patch "[PATCH] mm/ptdump: take the memory hotplug lock inside" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 59305202c67fea50378dcad0cc199dbc13a0e99a # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025081801-undertake-nuzzle-c4b1@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 59305202c67fea50378dcad0cc199dbc13a0e99a Mon Sep 17 00:00:00 2001 From: Anshuman Khandual <anshuman.khandual(a)arm.com> Date: Fri, 20 Jun 2025 10:54:27 +0530 Subject: [PATCH] mm/ptdump: take the memory hotplug lock inside ptdump_walk_pgd() Memory hot remove unmaps and tears down various kernel page table regions as required. The ptdump code can race with concurrent modifications of the kernel page tables. When leaf entries are modified concurrently, the dump code may log stale or inconsistent information for a VA range, but this is otherwise not harmful. But when intermediate levels of kernel page table are freed, the dump code will continue to use memory that has been freed and potentially reallocated for another purpose. In such cases, the ptdump code may dereference bogus addresses, leading to a number of potential problems. To avoid the above mentioned race condition, platforms such as arm64, riscv and s390 take memory hotplug lock, while dumping kernel page table via the sysfs interface /sys/kernel/debug/kernel_page_tables. Similar race condition exists while checking for pages that might have been marked W+X via /sys/kernel/debug/kernel_page_tables/check_wx_pages which in turn calls ptdump_check_wx(). Instead of solving this race condition again, let's just move the memory hotplug lock inside generic ptdump_check_wx() which will benefit both the scenarios. Drop get_online_mems() and put_online_mems() combination from all existing platform ptdump code paths. Link: https://lkml.kernel.org/r/20250620052427.2092093-1-anshuman.khandual@arm.com Fixes: bbd6ec605c0f ("arm64/mm: Enable memory hot remove") Signed-off-by: Anshuman Khandual <anshuman.khandual(a)arm.com> Acked-by: David Hildenbrand <david(a)redhat.com> Reviewed-by: Dev Jain <dev.jain(a)arm.com> Acked-by: Alexander Gordeev <agordeev(a)linux.ibm.com> [s390] Cc: Catalin Marinas <catalin.marinas(a)arm.com> Cc: Will Deacon <will(a)kernel.org> Cc: Ryan Roberts <ryan.roberts(a)arm.com> Cc: Paul Walmsley <paul.walmsley(a)sifive.com> Cc: Palmer Dabbelt <palmer(a)dabbelt.com> Cc: Alexander Gordeev <agordeev(a)linux.ibm.com> Cc: Gerald Schaefer <gerald.schaefer(a)linux.ibm.com> Cc: Heiko Carstens <hca(a)linux.ibm.com> Cc: Vasily Gorbik <gor(a)linux.ibm.com> Cc: Christian Borntraeger <borntraeger(a)linux.ibm.com> Cc: Sven Schnelle <svens(a)linux.ibm.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/arch/arm64/mm/ptdump_debugfs.c b/arch/arm64/mm/ptdump_debugfs.c index 68bf1a125502..1e308328c079 100644 --- a/arch/arm64/mm/ptdump_debugfs.c +++ b/arch/arm64/mm/ptdump_debugfs.c @@ -1,6 +1,5 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/debugfs.h> -#include <linux/memory_hotplug.h> #include <linux/seq_file.h> #include <asm/ptdump.h> @@ -9,9 +8,7 @@ static int ptdump_show(struct seq_file *m, void *v) { struct ptdump_info *info = m->private; - get_online_mems(); ptdump_walk(m, info); - put_online_mems(); return 0; } DEFINE_SHOW_ATTRIBUTE(ptdump); diff --git a/arch/riscv/mm/ptdump.c b/arch/riscv/mm/ptdump.c index 32922550a50a..3b51690cc876 100644 --- a/arch/riscv/mm/ptdump.c +++ b/arch/riscv/mm/ptdump.c @@ -6,7 +6,6 @@ #include <linux/efi.h> #include <linux/init.h> #include <linux/debugfs.h> -#include <linux/memory_hotplug.h> #include <linux/seq_file.h> #include <linux/ptdump.h> @@ -413,9 +412,7 @@ bool ptdump_check_wx(void) static int ptdump_show(struct seq_file *m, void *v) { - get_online_mems(); ptdump_walk(m, m->private); - put_online_mems(); return 0; } diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c index ac604b176660..9af2aae0a515 100644 --- a/arch/s390/mm/dump_pagetables.c +++ b/arch/s390/mm/dump_pagetables.c @@ -247,11 +247,9 @@ static int ptdump_show(struct seq_file *m, void *v) .marker = markers, }; - get_online_mems(); mutex_lock(&cpa_mutex); ptdump_walk_pgd(&st.ptdump, &init_mm, NULL); mutex_unlock(&cpa_mutex); - put_online_mems(); return 0; } DEFINE_SHOW_ATTRIBUTE(ptdump); diff --git a/mm/ptdump.c b/mm/ptdump.c index 61a352aa12ed..b600c7f864b8 100644 --- a/mm/ptdump.c +++ b/mm/ptdump.c @@ -176,6 +176,7 @@ void ptdump_walk_pgd(struct ptdump_state *st, struct mm_struct *mm, pgd_t *pgd) { const struct ptdump_range *range = st->range; + get_online_mems(); mmap_write_lock(mm); while (range->start != range->end) { walk_page_range_debug(mm, range->start, range->end, @@ -183,6 +184,7 @@ void ptdump_walk_pgd(struct ptdump_state *st, struct mm_struct *mm, pgd_t *pgd) range++; } mmap_write_unlock(mm); + put_online_mems(); /* Flush out the last page */ st->note_page_flush(st);

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FAILED: patch "[PATCH] mm/ptdump: take the memory hotplug lock inside" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 59305202c67fea50378dcad0cc199dbc13a0e99a # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025081800-autopilot-booted-fb7f@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 59305202c67fea50378dcad0cc199dbc13a0e99a Mon Sep 17 00:00:00 2001 From: Anshuman Khandual <anshuman.khandual(a)arm.com> Date: Fri, 20 Jun 2025 10:54:27 +0530 Subject: [PATCH] mm/ptdump: take the memory hotplug lock inside ptdump_walk_pgd() Memory hot remove unmaps and tears down various kernel page table regions as required. The ptdump code can race with concurrent modifications of the kernel page tables. When leaf entries are modified concurrently, the dump code may log stale or inconsistent information for a VA range, but this is otherwise not harmful. But when intermediate levels of kernel page table are freed, the dump code will continue to use memory that has been freed and potentially reallocated for another purpose. In such cases, the ptdump code may dereference bogus addresses, leading to a number of potential problems. To avoid the above mentioned race condition, platforms such as arm64, riscv and s390 take memory hotplug lock, while dumping kernel page table via the sysfs interface /sys/kernel/debug/kernel_page_tables. Similar race condition exists while checking for pages that might have been marked W+X via /sys/kernel/debug/kernel_page_tables/check_wx_pages which in turn calls ptdump_check_wx(). Instead of solving this race condition again, let's just move the memory hotplug lock inside generic ptdump_check_wx() which will benefit both the scenarios. Drop get_online_mems() and put_online_mems() combination from all existing platform ptdump code paths. Link: https://lkml.kernel.org/r/20250620052427.2092093-1-anshuman.khandual@arm.com Fixes: bbd6ec605c0f ("arm64/mm: Enable memory hot remove") Signed-off-by: Anshuman Khandual <anshuman.khandual(a)arm.com> Acked-by: David Hildenbrand <david(a)redhat.com> Reviewed-by: Dev Jain <dev.jain(a)arm.com> Acked-by: Alexander Gordeev <agordeev(a)linux.ibm.com> [s390] Cc: Catalin Marinas <catalin.marinas(a)arm.com> Cc: Will Deacon <will(a)kernel.org> Cc: Ryan Roberts <ryan.roberts(a)arm.com> Cc: Paul Walmsley <paul.walmsley(a)sifive.com> Cc: Palmer Dabbelt <palmer(a)dabbelt.com> Cc: Alexander Gordeev <agordeev(a)linux.ibm.com> Cc: Gerald Schaefer <gerald.schaefer(a)linux.ibm.com> Cc: Heiko Carstens <hca(a)linux.ibm.com> Cc: Vasily Gorbik <gor(a)linux.ibm.com> Cc: Christian Borntraeger <borntraeger(a)linux.ibm.com> Cc: Sven Schnelle <svens(a)linux.ibm.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/arch/arm64/mm/ptdump_debugfs.c b/arch/arm64/mm/ptdump_debugfs.c index 68bf1a125502..1e308328c079 100644 --- a/arch/arm64/mm/ptdump_debugfs.c +++ b/arch/arm64/mm/ptdump_debugfs.c @@ -1,6 +1,5 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/debugfs.h> -#include <linux/memory_hotplug.h> #include <linux/seq_file.h> #include <asm/ptdump.h> @@ -9,9 +8,7 @@ static int ptdump_show(struct seq_file *m, void *v) { struct ptdump_info *info = m->private; - get_online_mems(); ptdump_walk(m, info); - put_online_mems(); return 0; } DEFINE_SHOW_ATTRIBUTE(ptdump); diff --git a/arch/riscv/mm/ptdump.c b/arch/riscv/mm/ptdump.c index 32922550a50a..3b51690cc876 100644 --- a/arch/riscv/mm/ptdump.c +++ b/arch/riscv/mm/ptdump.c @@ -6,7 +6,6 @@ #include <linux/efi.h> #include <linux/init.h> #include <linux/debugfs.h> -#include <linux/memory_hotplug.h> #include <linux/seq_file.h> #include <linux/ptdump.h> @@ -413,9 +412,7 @@ bool ptdump_check_wx(void) static int ptdump_show(struct seq_file *m, void *v) { - get_online_mems(); ptdump_walk(m, m->private); - put_online_mems(); return 0; } diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c index ac604b176660..9af2aae0a515 100644 --- a/arch/s390/mm/dump_pagetables.c +++ b/arch/s390/mm/dump_pagetables.c @@ -247,11 +247,9 @@ static int ptdump_show(struct seq_file *m, void *v) .marker = markers, }; - get_online_mems(); mutex_lock(&cpa_mutex); ptdump_walk_pgd(&st.ptdump, &init_mm, NULL); mutex_unlock(&cpa_mutex); - put_online_mems(); return 0; } DEFINE_SHOW_ATTRIBUTE(ptdump); diff --git a/mm/ptdump.c b/mm/ptdump.c index 61a352aa12ed..b600c7f864b8 100644 --- a/mm/ptdump.c +++ b/mm/ptdump.c @@ -176,6 +176,7 @@ void ptdump_walk_pgd(struct ptdump_state *st, struct mm_struct *mm, pgd_t *pgd) { const struct ptdump_range *range = st->range; + get_online_mems(); mmap_write_lock(mm); while (range->start != range->end) { walk_page_range_debug(mm, range->start, range->end, @@ -183,6 +184,7 @@ void ptdump_walk_pgd(struct ptdump_state *st, struct mm_struct *mm, pgd_t *pgd) range++; } mmap_write_unlock(mm); + put_online_mems(); /* Flush out the last page */ st->note_page_flush(st);

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FAILED: patch "[PATCH] btrfs: populate otime when logging an inode item" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 1ef94169db0958d6de39f9ea6e063ce887342e2d # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025081801-shortlist-acutely-2100@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 1ef94169db0958d6de39f9ea6e063ce887342e2d Mon Sep 17 00:00:00 2001 From: Qu Wenruo <wqu(a)suse.com> Date: Wed, 2 Jul 2025 15:08:13 +0930 Subject: [PATCH] btrfs: populate otime when logging an inode item [TEST FAILURE WITH EXPERIMENTAL FEATURES] When running test case generic/508, the test case will fail with the new btrfs shutdown support: generic/508 - output mismatch (see /home/adam/xfstests/results//generic/508.out.bad) --- tests/generic/508.out 2022-05-11 11:25:30.806666664 +0930 +++ /home/adam/xfstests/results//generic/508.out.bad 2025-07-02 14:53:22.401824212 +0930 @@ -1,2 +1,6 @@ QA output created by 508 Silence is golden +Before: +After : stat.btime = Thu Jan 1 09:30:00 1970 +Before: +After : stat.btime = Wed Jul 2 14:53:22 2025 ... (Run 'diff -u /home/adam/xfstests/tests/generic/508.out /home/adam/xfstests/results//generic/508.out.bad' to see the entire diff) Ran: generic/508 Failures: generic/508 Failed 1 of 1 tests Please note that the test case requires shutdown support, thus the test case will be skipped using the current upstream kernel, as it doesn't have shutdown ioctl support. [CAUSE] The direct cause the 0 time stamp in the log tree: leaf 30507008 items 2 free space 16057 generation 9 owner TREE_LOG leaf 30507008 flags 0x1(WRITTEN) backref revision 1 checksum stored e522548d checksum calced e522548d fs uuid 57d45451-481e-43e4-aa93-289ad707a3a0 chunk uuid d52bd3fd-5163-4337-98a7-7986993ad398 item 0 key (257 INODE_ITEM 0) itemoff 16123 itemsize 160 generation 9 transid 9 size 0 nbytes 0 block group 0 mode 100644 links 1 uid 0 gid 0 rdev 0 sequence 1 flags 0x0(none) atime 1751432947.492000000 (2025-07-02 14:39:07) ctime 1751432947.492000000 (2025-07-02 14:39:07) mtime 1751432947.492000000 (2025-07-02 14:39:07) otime 0.0 (1970-01-01 09:30:00) <<< But the old fs tree has all the correct time stamp: btrfs-progs v6.12 fs tree key (FS_TREE ROOT_ITEM 0) leaf 30425088 items 2 free space 16061 generation 5 owner FS_TREE leaf 30425088 flags 0x1(WRITTEN) backref revision 1 checksum stored 48f6c57e checksum calced 48f6c57e fs uuid 57d45451-481e-43e4-aa93-289ad707a3a0 chunk uuid d52bd3fd-5163-4337-98a7-7986993ad398 item 0 key (256 INODE_ITEM 0) itemoff 16123 itemsize 160 generation 3 transid 0 size 0 nbytes 16384 block group 0 mode 40755 links 1 uid 0 gid 0 rdev 0 sequence 0 flags 0x0(none) atime 1751432947.0 (2025-07-02 14:39:07) ctime 1751432947.0 (2025-07-02 14:39:07) mtime 1751432947.0 (2025-07-02 14:39:07) otime 1751432947.0 (2025-07-02 14:39:07) <<< The root cause is that fill_inode_item() in tree-log.c is only populating a/c/m time, not the otime (or btime in statx output). Part of the reason is that, the vfs inode only has a/c/m time, no native btime support yet. [FIX] Thankfully btrfs has its otime stored in btrfs_inode::i_otime_sec and btrfs_inode::i_otime_nsec. So what we really need is just fill the otime time stamp in fill_inode_item() of tree-log.c There is another fill_inode_item() in inode.c, which is doing the proper otime population. Fixes: 94edf4ae43a5 ("Btrfs: don't bother committing delayed inode updates when fsyncing") CC: stable(a)vger.kernel.org Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: Qu Wenruo <wqu(a)suse.com> Reviewed-by: David Sterba <dsterba(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index 1e805dabfc4b..ab0815d9e7e5 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -4233,6 +4233,9 @@ static void fill_inode_item(struct btrfs_trans_handle *trans, btrfs_set_timespec_sec(leaf, &item->ctime, inode_get_ctime_sec(inode)); btrfs_set_timespec_nsec(leaf, &item->ctime, inode_get_ctime_nsec(inode)); + btrfs_set_timespec_sec(leaf, &item->otime, BTRFS_I(inode)->i_otime_sec); + btrfs_set_timespec_nsec(leaf, &item->otime, BTRFS_I(inode)->i_otime_nsec); + /* * We do not need to set the nbytes field, in fact during a fast fsync * its value may not even be correct, since a fast fsync does not wait

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FAILED: patch "[PATCH] mm/ptdump: take the memory hotplug lock inside" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 59305202c67fea50378dcad0cc199dbc13a0e99a # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025081859-excess-willfully-0f01@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 59305202c67fea50378dcad0cc199dbc13a0e99a Mon Sep 17 00:00:00 2001 From: Anshuman Khandual <anshuman.khandual(a)arm.com> Date: Fri, 20 Jun 2025 10:54:27 +0530 Subject: [PATCH] mm/ptdump: take the memory hotplug lock inside ptdump_walk_pgd() Memory hot remove unmaps and tears down various kernel page table regions as required. The ptdump code can race with concurrent modifications of the kernel page tables. When leaf entries are modified concurrently, the dump code may log stale or inconsistent information for a VA range, but this is otherwise not harmful. But when intermediate levels of kernel page table are freed, the dump code will continue to use memory that has been freed and potentially reallocated for another purpose. In such cases, the ptdump code may dereference bogus addresses, leading to a number of potential problems. To avoid the above mentioned race condition, platforms such as arm64, riscv and s390 take memory hotplug lock, while dumping kernel page table via the sysfs interface /sys/kernel/debug/kernel_page_tables. Similar race condition exists while checking for pages that might have been marked W+X via /sys/kernel/debug/kernel_page_tables/check_wx_pages which in turn calls ptdump_check_wx(). Instead of solving this race condition again, let's just move the memory hotplug lock inside generic ptdump_check_wx() which will benefit both the scenarios. Drop get_online_mems() and put_online_mems() combination from all existing platform ptdump code paths. Link: https://lkml.kernel.org/r/20250620052427.2092093-1-anshuman.khandual@arm.com Fixes: bbd6ec605c0f ("arm64/mm: Enable memory hot remove") Signed-off-by: Anshuman Khandual <anshuman.khandual(a)arm.com> Acked-by: David Hildenbrand <david(a)redhat.com> Reviewed-by: Dev Jain <dev.jain(a)arm.com> Acked-by: Alexander Gordeev <agordeev(a)linux.ibm.com> [s390] Cc: Catalin Marinas <catalin.marinas(a)arm.com> Cc: Will Deacon <will(a)kernel.org> Cc: Ryan Roberts <ryan.roberts(a)arm.com> Cc: Paul Walmsley <paul.walmsley(a)sifive.com> Cc: Palmer Dabbelt <palmer(a)dabbelt.com> Cc: Alexander Gordeev <agordeev(a)linux.ibm.com> Cc: Gerald Schaefer <gerald.schaefer(a)linux.ibm.com> Cc: Heiko Carstens <hca(a)linux.ibm.com> Cc: Vasily Gorbik <gor(a)linux.ibm.com> Cc: Christian Borntraeger <borntraeger(a)linux.ibm.com> Cc: Sven Schnelle <svens(a)linux.ibm.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/arch/arm64/mm/ptdump_debugfs.c b/arch/arm64/mm/ptdump_debugfs.c index 68bf1a125502..1e308328c079 100644 --- a/arch/arm64/mm/ptdump_debugfs.c +++ b/arch/arm64/mm/ptdump_debugfs.c @@ -1,6 +1,5 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/debugfs.h> -#include <linux/memory_hotplug.h> #include <linux/seq_file.h> #include <asm/ptdump.h> @@ -9,9 +8,7 @@ static int ptdump_show(struct seq_file *m, void *v) { struct ptdump_info *info = m->private; - get_online_mems(); ptdump_walk(m, info); - put_online_mems(); return 0; } DEFINE_SHOW_ATTRIBUTE(ptdump); diff --git a/arch/riscv/mm/ptdump.c b/arch/riscv/mm/ptdump.c index 32922550a50a..3b51690cc876 100644 --- a/arch/riscv/mm/ptdump.c +++ b/arch/riscv/mm/ptdump.c @@ -6,7 +6,6 @@ #include <linux/efi.h> #include <linux/init.h> #include <linux/debugfs.h> -#include <linux/memory_hotplug.h> #include <linux/seq_file.h> #include <linux/ptdump.h> @@ -413,9 +412,7 @@ bool ptdump_check_wx(void) static int ptdump_show(struct seq_file *m, void *v) { - get_online_mems(); ptdump_walk(m, m->private); - put_online_mems(); return 0; } diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c index ac604b176660..9af2aae0a515 100644 --- a/arch/s390/mm/dump_pagetables.c +++ b/arch/s390/mm/dump_pagetables.c @@ -247,11 +247,9 @@ static int ptdump_show(struct seq_file *m, void *v) .marker = markers, }; - get_online_mems(); mutex_lock(&cpa_mutex); ptdump_walk_pgd(&st.ptdump, &init_mm, NULL); mutex_unlock(&cpa_mutex); - put_online_mems(); return 0; } DEFINE_SHOW_ATTRIBUTE(ptdump); diff --git a/mm/ptdump.c b/mm/ptdump.c index 61a352aa12ed..b600c7f864b8 100644 --- a/mm/ptdump.c +++ b/mm/ptdump.c @@ -176,6 +176,7 @@ void ptdump_walk_pgd(struct ptdump_state *st, struct mm_struct *mm, pgd_t *pgd) { const struct ptdump_range *range = st->range; + get_online_mems(); mmap_write_lock(mm); while (range->start != range->end) { walk_page_range_debug(mm, range->start, range->end, @@ -183,6 +184,7 @@ void ptdump_walk_pgd(struct ptdump_state *st, struct mm_struct *mm, pgd_t *pgd) range++; } mmap_write_unlock(mm); + put_online_mems(); /* Flush out the last page */ st->note_page_flush(st);

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FAILED: patch "[PATCH] mm/ptdump: take the memory hotplug lock inside" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 59305202c67fea50378dcad0cc199dbc13a0e99a # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025081858-sabbath-blunt-7735@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 59305202c67fea50378dcad0cc199dbc13a0e99a Mon Sep 17 00:00:00 2001 From: Anshuman Khandual <anshuman.khandual(a)arm.com> Date: Fri, 20 Jun 2025 10:54:27 +0530 Subject: [PATCH] mm/ptdump: take the memory hotplug lock inside ptdump_walk_pgd() Memory hot remove unmaps and tears down various kernel page table regions as required. The ptdump code can race with concurrent modifications of the kernel page tables. When leaf entries are modified concurrently, the dump code may log stale or inconsistent information for a VA range, but this is otherwise not harmful. But when intermediate levels of kernel page table are freed, the dump code will continue to use memory that has been freed and potentially reallocated for another purpose. In such cases, the ptdump code may dereference bogus addresses, leading to a number of potential problems. To avoid the above mentioned race condition, platforms such as arm64, riscv and s390 take memory hotplug lock, while dumping kernel page table via the sysfs interface /sys/kernel/debug/kernel_page_tables. Similar race condition exists while checking for pages that might have been marked W+X via /sys/kernel/debug/kernel_page_tables/check_wx_pages which in turn calls ptdump_check_wx(). Instead of solving this race condition again, let's just move the memory hotplug lock inside generic ptdump_check_wx() which will benefit both the scenarios. Drop get_online_mems() and put_online_mems() combination from all existing platform ptdump code paths. Link: https://lkml.kernel.org/r/20250620052427.2092093-1-anshuman.khandual@arm.com Fixes: bbd6ec605c0f ("arm64/mm: Enable memory hot remove") Signed-off-by: Anshuman Khandual <anshuman.khandual(a)arm.com> Acked-by: David Hildenbrand <david(a)redhat.com> Reviewed-by: Dev Jain <dev.jain(a)arm.com> Acked-by: Alexander Gordeev <agordeev(a)linux.ibm.com> [s390] Cc: Catalin Marinas <catalin.marinas(a)arm.com> Cc: Will Deacon <will(a)kernel.org> Cc: Ryan Roberts <ryan.roberts(a)arm.com> Cc: Paul Walmsley <paul.walmsley(a)sifive.com> Cc: Palmer Dabbelt <palmer(a)dabbelt.com> Cc: Alexander Gordeev <agordeev(a)linux.ibm.com> Cc: Gerald Schaefer <gerald.schaefer(a)linux.ibm.com> Cc: Heiko Carstens <hca(a)linux.ibm.com> Cc: Vasily Gorbik <gor(a)linux.ibm.com> Cc: Christian Borntraeger <borntraeger(a)linux.ibm.com> Cc: Sven Schnelle <svens(a)linux.ibm.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/arch/arm64/mm/ptdump_debugfs.c b/arch/arm64/mm/ptdump_debugfs.c index 68bf1a125502..1e308328c079 100644 --- a/arch/arm64/mm/ptdump_debugfs.c +++ b/arch/arm64/mm/ptdump_debugfs.c @@ -1,6 +1,5 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/debugfs.h> -#include <linux/memory_hotplug.h> #include <linux/seq_file.h> #include <asm/ptdump.h> @@ -9,9 +8,7 @@ static int ptdump_show(struct seq_file *m, void *v) { struct ptdump_info *info = m->private; - get_online_mems(); ptdump_walk(m, info); - put_online_mems(); return 0; } DEFINE_SHOW_ATTRIBUTE(ptdump); diff --git a/arch/riscv/mm/ptdump.c b/arch/riscv/mm/ptdump.c index 32922550a50a..3b51690cc876 100644 --- a/arch/riscv/mm/ptdump.c +++ b/arch/riscv/mm/ptdump.c @@ -6,7 +6,6 @@ #include <linux/efi.h> #include <linux/init.h> #include <linux/debugfs.h> -#include <linux/memory_hotplug.h> #include <linux/seq_file.h> #include <linux/ptdump.h> @@ -413,9 +412,7 @@ bool ptdump_check_wx(void) static int ptdump_show(struct seq_file *m, void *v) { - get_online_mems(); ptdump_walk(m, m->private); - put_online_mems(); return 0; } diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c index ac604b176660..9af2aae0a515 100644 --- a/arch/s390/mm/dump_pagetables.c +++ b/arch/s390/mm/dump_pagetables.c @@ -247,11 +247,9 @@ static int ptdump_show(struct seq_file *m, void *v) .marker = markers, }; - get_online_mems(); mutex_lock(&cpa_mutex); ptdump_walk_pgd(&st.ptdump, &init_mm, NULL); mutex_unlock(&cpa_mutex); - put_online_mems(); return 0; } DEFINE_SHOW_ATTRIBUTE(ptdump); diff --git a/mm/ptdump.c b/mm/ptdump.c index 61a352aa12ed..b600c7f864b8 100644 --- a/mm/ptdump.c +++ b/mm/ptdump.c @@ -176,6 +176,7 @@ void ptdump_walk_pgd(struct ptdump_state *st, struct mm_struct *mm, pgd_t *pgd) { const struct ptdump_range *range = st->range; + get_online_mems(); mmap_write_lock(mm); while (range->start != range->end) { walk_page_range_debug(mm, range->start, range->end, @@ -183,6 +184,7 @@ void ptdump_walk_pgd(struct ptdump_state *st, struct mm_struct *mm, pgd_t *pgd) range++; } mmap_write_unlock(mm); + put_online_mems(); /* Flush out the last page */ st->note_page_flush(st);

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FAILED: patch "[PATCH] btrfs: send: use fallocate for hole punching with send stream" failed to apply to 6.12-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x 005b0a0c24e1628313e951516b675109a92cacfe # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025081827-washed-yelp-3c3e@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 005b0a0c24e1628313e951516b675109a92cacfe Mon Sep 17 00:00:00 2001 From: Filipe Manana <fdmanana(a)suse.com> Date: Fri, 18 Jul 2025 13:07:29 +0100 Subject: [PATCH] btrfs: send: use fallocate for hole punching with send stream v2 Currently holes are sent as writes full of zeroes, which results in unnecessarily using disk space at the receiving end and increasing the stream size. In some cases we avoid sending writes of zeroes, like during a full send operation where we just skip writes for holes. But for some cases we fill previous holes with writes of zeroes too, like in this scenario: 1) We have a file with a hole in the range [2M, 3M), we snapshot the subvolume and do a full send. The range [2M, 3M) stays as a hole at the receiver since we skip sending write commands full of zeroes; 2) We punch a hole for the range [3M, 4M) in our file, so that now it has a 2M hole in the range [2M, 4M), and snapshot the subvolume. Now if we do an incremental send, we will send write commands full of zeroes for the range [2M, 4M), removing the hole for [2M, 3M) at the receiver. We could improve cases such as this last one by doing additional comparisons of file extent items (or their absence) between the parent and send snapshots, but that's a lot of code to add plus additional CPU and IO costs. Since the send stream v2 already has a fallocate command and btrfs-progs implements a callback to execute fallocate since the send stream v2 support was added to it, update the kernel to use fallocate for punching holes for V2+ streams. Test coverage is provided by btrfs/284 which is a version of btrfs/007 that exercises send stream v2 instead of v1, using fsstress with random operations and fssum to verify file contents. Link: https://github.com/kdave/btrfs-progs/issues/1001 CC: stable(a)vger.kernel.org # 6.1+ Reviewed-by: Boris Burkov <boris(a)bur.io> Signed-off-by: Filipe Manana <fdmanana(a)suse.com> Reviewed-by: David Sterba <dsterba(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 09822e766e41..7664025a5af4 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -4,6 +4,7 @@ */ #include <linux/bsearch.h> +#include <linux/falloc.h> #include <linux/fs.h> #include <linux/file.h> #include <linux/sort.h> @@ -5405,6 +5406,30 @@ static int send_update_extent(struct send_ctx *sctx, return ret; } +static int send_fallocate(struct send_ctx *sctx, u32 mode, u64 offset, u64 len) +{ + struct fs_path *path; + int ret; + + path = get_cur_inode_path(sctx); + if (IS_ERR(path)) + return PTR_ERR(path); + + ret = begin_cmd(sctx, BTRFS_SEND_C_FALLOCATE); + if (ret < 0) + return ret; + + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path); + TLV_PUT_U32(sctx, BTRFS_SEND_A_FALLOCATE_MODE, mode); + TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset); + TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, len); + + ret = send_cmd(sctx); + +tlv_put_failure: + return ret; +} + static int send_hole(struct send_ctx *sctx, u64 end) { struct fs_path *p = NULL; @@ -5412,6 +5437,14 @@ static int send_hole(struct send_ctx *sctx, u64 end) u64 offset = sctx->cur_inode_last_extent; int ret = 0; + /* + * Starting with send stream v2 we have fallocate and can use it to + * punch holes instead of sending writes full of zeroes. + */ + if (proto_cmd_ok(sctx, BTRFS_SEND_C_FALLOCATE)) + return send_fallocate(sctx, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, + offset, end - offset); + /* * A hole that starts at EOF or beyond it. Since we do not yet support * fallocate (for extent preallocation and hole punching), sending a

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FAILED: patch "[PATCH] btrfs: populate otime when logging an inode item" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 1ef94169db0958d6de39f9ea6e063ce887342e2d # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025081801-ended-viewless-5ac7@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 1ef94169db0958d6de39f9ea6e063ce887342e2d Mon Sep 17 00:00:00 2001 From: Qu Wenruo <wqu(a)suse.com> Date: Wed, 2 Jul 2025 15:08:13 +0930 Subject: [PATCH] btrfs: populate otime when logging an inode item [TEST FAILURE WITH EXPERIMENTAL FEATURES] When running test case generic/508, the test case will fail with the new btrfs shutdown support: generic/508 - output mismatch (see /home/adam/xfstests/results//generic/508.out.bad) --- tests/generic/508.out 2022-05-11 11:25:30.806666664 +0930 +++ /home/adam/xfstests/results//generic/508.out.bad 2025-07-02 14:53:22.401824212 +0930 @@ -1,2 +1,6 @@ QA output created by 508 Silence is golden +Before: +After : stat.btime = Thu Jan 1 09:30:00 1970 +Before: +After : stat.btime = Wed Jul 2 14:53:22 2025 ... (Run 'diff -u /home/adam/xfstests/tests/generic/508.out /home/adam/xfstests/results//generic/508.out.bad' to see the entire diff) Ran: generic/508 Failures: generic/508 Failed 1 of 1 tests Please note that the test case requires shutdown support, thus the test case will be skipped using the current upstream kernel, as it doesn't have shutdown ioctl support. [CAUSE] The direct cause the 0 time stamp in the log tree: leaf 30507008 items 2 free space 16057 generation 9 owner TREE_LOG leaf 30507008 flags 0x1(WRITTEN) backref revision 1 checksum stored e522548d checksum calced e522548d fs uuid 57d45451-481e-43e4-aa93-289ad707a3a0 chunk uuid d52bd3fd-5163-4337-98a7-7986993ad398 item 0 key (257 INODE_ITEM 0) itemoff 16123 itemsize 160 generation 9 transid 9 size 0 nbytes 0 block group 0 mode 100644 links 1 uid 0 gid 0 rdev 0 sequence 1 flags 0x0(none) atime 1751432947.492000000 (2025-07-02 14:39:07) ctime 1751432947.492000000 (2025-07-02 14:39:07) mtime 1751432947.492000000 (2025-07-02 14:39:07) otime 0.0 (1970-01-01 09:30:00) <<< But the old fs tree has all the correct time stamp: btrfs-progs v6.12 fs tree key (FS_TREE ROOT_ITEM 0) leaf 30425088 items 2 free space 16061 generation 5 owner FS_TREE leaf 30425088 flags 0x1(WRITTEN) backref revision 1 checksum stored 48f6c57e checksum calced 48f6c57e fs uuid 57d45451-481e-43e4-aa93-289ad707a3a0 chunk uuid d52bd3fd-5163-4337-98a7-7986993ad398 item 0 key (256 INODE_ITEM 0) itemoff 16123 itemsize 160 generation 3 transid 0 size 0 nbytes 16384 block group 0 mode 40755 links 1 uid 0 gid 0 rdev 0 sequence 0 flags 0x0(none) atime 1751432947.0 (2025-07-02 14:39:07) ctime 1751432947.0 (2025-07-02 14:39:07) mtime 1751432947.0 (2025-07-02 14:39:07) otime 1751432947.0 (2025-07-02 14:39:07) <<< The root cause is that fill_inode_item() in tree-log.c is only populating a/c/m time, not the otime (or btime in statx output). Part of the reason is that, the vfs inode only has a/c/m time, no native btime support yet. [FIX] Thankfully btrfs has its otime stored in btrfs_inode::i_otime_sec and btrfs_inode::i_otime_nsec. So what we really need is just fill the otime time stamp in fill_inode_item() of tree-log.c There is another fill_inode_item() in inode.c, which is doing the proper otime population. Fixes: 94edf4ae43a5 ("Btrfs: don't bother committing delayed inode updates when fsyncing") CC: stable(a)vger.kernel.org Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: Qu Wenruo <wqu(a)suse.com> Reviewed-by: David Sterba <dsterba(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index 1e805dabfc4b..ab0815d9e7e5 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -4233,6 +4233,9 @@ static void fill_inode_item(struct btrfs_trans_handle *trans, btrfs_set_timespec_sec(leaf, &item->ctime, inode_get_ctime_sec(inode)); btrfs_set_timespec_nsec(leaf, &item->ctime, inode_get_ctime_nsec(inode)); + btrfs_set_timespec_sec(leaf, &item->otime, BTRFS_I(inode)->i_otime_sec); + btrfs_set_timespec_nsec(leaf, &item->otime, BTRFS_I(inode)->i_otime_nsec); + /* * We do not need to set the nbytes field, in fact during a fast fsync * its value may not even be correct, since a fast fsync does not wait

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FAILED: patch "[PATCH] net/sched: ets: use old 'nbands' while purging unused classes" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 87c6efc5ce9c126ae4a781bc04504b83780e3650 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025081858-blurred-unlinked-7eae@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 87c6efc5ce9c126ae4a781bc04504b83780e3650 Mon Sep 17 00:00:00 2001 From: Davide Caratti <dcaratti(a)redhat.com> Date: Tue, 12 Aug 2025 18:40:29 +0200 Subject: [PATCH] net/sched: ets: use old 'nbands' while purging unused classes Shuang reported sch_ets test-case [1] crashing in ets_class_qlen_notify() after recent changes from Lion [2]. The problem is: in ets_qdisc_change() we purge unused DWRR queues; the value of 'q->nbands' is the new one, and the cleanup should be done with the old one. The problem is here since my first attempts to fix ets_qdisc_change(), but it surfaced again after the recent qdisc len accounting fixes. Fix it purging idle DWRR queues before assigning a new value of 'q->nbands', so that all purge operations find a consistent configuration: - old 'q->nbands' because it's needed by ets_class_find() - old 'q->nstrict' because it's needed by ets_class_is_strict() BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 62 UID: 0 PID: 39457 Comm: tc Kdump: loaded Not tainted 6.12.0-116.el10.x86_64 #1 PREEMPT(voluntary) Hardware name: Dell Inc. PowerEdge R640/06DKY5, BIOS 2.12.2 07/09/2021 RIP: 0010:__list_del_entry_valid_or_report+0x4/0x80 Code: ff 4c 39 c7 0f 84 39 19 8e ff b8 01 00 00 00 c3 cc cc cc cc 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <48> 8b 17 48 8b 4f 08 48 85 d2 0f 84 56 19 8e ff 48 85 c9 0f 84 ab RSP: 0018:ffffba186009f400 EFLAGS: 00010202 RAX: 00000000000000d6 RBX: 0000000000000000 RCX: 0000000000000004 RDX: ffff9f0fa29b69c0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffffc12c2400 R08: 0000000000000008 R09: 0000000000000004 R10: ffffffffffffffff R11: 0000000000000004 R12: 0000000000000000 R13: ffff9f0f8cfe0000 R14: 0000000000100005 R15: 0000000000000000 FS: 00007f2154f37480(0000) GS:ffff9f269c1c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000001530be001 CR4: 00000000007726f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> ets_class_qlen_notify+0x65/0x90 [sch_ets] qdisc_tree_reduce_backlog+0x74/0x110 ets_qdisc_change+0x630/0xa40 [sch_ets] __tc_modify_qdisc.constprop.0+0x216/0x7f0 tc_modify_qdisc+0x7c/0x120 rtnetlink_rcv_msg+0x145/0x3f0 netlink_rcv_skb+0x53/0x100 netlink_unicast+0x245/0x390 netlink_sendmsg+0x21b/0x470 ____sys_sendmsg+0x39d/0x3d0 ___sys_sendmsg+0x9a/0xe0 __sys_sendmsg+0x7a/0xd0 do_syscall_64+0x7d/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f2155114084 Code: 89 02 b8 ff ff ff ff eb bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 80 3d 25 f0 0c 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89 RSP: 002b:00007fff1fd7a988 EFLAGS: 00000202 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000560ec063e5e0 RCX: 00007f2155114084 RDX: 0000000000000000 RSI: 00007fff1fd7a9f0 RDI: 0000000000000003 RBP: 00007fff1fd7aa60 R08: 0000000000000010 R09: 000000000000003f R10: 0000560ee9b3a010 R11: 0000000000000202 R12: 00007fff1fd7aae0 R13: 000000006891ccde R14: 0000560ec063e5e0 R15: 00007fff1fd7aad0 </TASK> [1] https://lore.kernel.org/netdev/e08c7f4a6882f260011909a868311c6e9b54f3e4.163… [2] https://lore.kernel.org/netdev/d912cbd7-193b-4269-9857-525bee8bbb6a@gmail.c… Cc: stable(a)vger.kernel.org Fixes: 103406b38c60 ("net/sched: Always pass notifications when child class becomes empty") Fixes: c062f2a0b04d ("net/sched: sch_ets: don't remove idle classes from the round-robin list") Fixes: dcc68b4d8084 ("net: sch_ets: Add a new Qdisc") Reported-by: Li Shuang <shuali(a)redhat.com> Closes: https://issues.redhat.com/browse/RHEL-108026 Reviewed-by: Petr Machata <petrm(a)nvidia.com> Co-developed-by: Ivan Vecera <ivecera(a)redhat.com> Signed-off-by: Ivan Vecera <ivecera(a)redhat.com> Signed-off-by: Davide Caratti <dcaratti(a)redhat.com> Link: https://patch.msgid.link/7928ff6d17db47a2ae7cc205c44777b1f1950545.175501608… Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> diff --git a/net/sched/sch_ets.c b/net/sched/sch_ets.c index 037f764822b9..82635dd2cfa5 100644 --- a/net/sched/sch_ets.c +++ b/net/sched/sch_ets.c @@ -651,6 +651,12 @@ static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt, sch_tree_lock(sch); + for (i = nbands; i < oldbands; i++) { + if (i >= q->nstrict && q->classes[i].qdisc->q.qlen) + list_del_init(&q->classes[i].alist); + qdisc_purge_queue(q->classes[i].qdisc); + } + WRITE_ONCE(q->nbands, nbands); for (i = nstrict; i < q->nstrict; i++) { if (q->classes[i].qdisc->q.qlen) { @@ -658,11 +664,6 @@ static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt, q->classes[i].deficit = quanta[i]; } } - for (i = q->nbands; i < oldbands; i++) { - if (i >= q->nstrict && q->classes[i].qdisc->q.qlen) - list_del_init(&q->classes[i].alist); - qdisc_purge_queue(q->classes[i].qdisc); - } WRITE_ONCE(q->nstrict, nstrict); memcpy(q->prio2band, priomap, sizeof(priomap));

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FAILED: patch "[PATCH] btrfs: fix ssd_spread overallocation" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 807d9023e75fc20bfd6dd2ac0408ce4af53f1648 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025081832-unearned-monopoly-13b1@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 807d9023e75fc20bfd6dd2ac0408ce4af53f1648 Mon Sep 17 00:00:00 2001 From: Boris Burkov <boris(a)bur.io> Date: Mon, 14 Jul 2025 16:44:28 -0700 Subject: [PATCH] btrfs: fix ssd_spread overallocation If the ssd_spread mount option is enabled, then we run the so called clustered allocator for data block groups. In practice, this results in creating a btrfs_free_cluster which caches a block_group and borrows its free extents for allocation. Since the introduction of allocation size classes in 6.1, there has been a bug in the interaction between that feature and ssd_spread. find_free_extent() has a number of nested loops. The loop going over the allocation stages, stored in ffe_ctl->loop and managed by find_free_extent_update_loop(), the loop over the raid levels, and the loop over all the block_groups in a space_info. The size class feature relies on the block_group loop to ensure it gets a chance to see a block_group of a given size class. However, the clustered allocator uses the cached cluster block_group and breaks that loop. Each call to do_allocation() will really just go back to the same cached block_group. Normally, this is OK, as the allocation either succeeds and we don't want to loop any more or it fails, and we clear the cluster and return its space to the block_group. But with size classes, the allocation can succeed, then later fail, outside of do_allocation() due to size class mismatch. That latter failure is not properly handled due to the highly complex multi loop logic. The result is a painful loop where we continue to allocate the same num_bytes from the cluster in a tight loop until it fails and releases the cluster and lets us try a new block_group. But by then, we have skipped great swaths of the available block_groups and are likely to fail to allocate, looping the outer loop. In pathological cases like the reproducer below, the cached block_group is often the very last one, in which case we don't perform this tight bg loop but instead rip through the ffe stages to LOOP_CHUNK_ALLOC and allocate a chunk, which is now the last one, and we enter the tight inner loop until an allocation failure. Then allocation succeeds on the final block_group and if the next allocation is a size mismatch, the exact same thing happens again. Triggering this is as easy as mounting with -o ssd_spread and then running: mount -o ssd_spread $dev $mnt dd if=/dev/zero of=$mnt/big bs=16M count=1 &>/dev/null dd if=/dev/zero of=$mnt/med bs=4M count=1 &>/dev/null sync if you do the two writes + sync in a loop, you can force btrfs to spin an excessive amount on semi-successful clustered allocations, before ultimately failing and advancing to the stage where we force a chunk allocation. This results in 2G of data allocated per iteration, despite only using ~20M of data. By using a small size classed extent, the inner loop takes longer and we can spin for longer. The simplest, shortest term fix to unbreak this is to make the clustered allocator size_class aware in the dumbest way, where it fails on size class mismatch. This may hinder the operation of the clustered allocator, but better hindered than completely broken and terribly overallocating. Further re-design improvements are also in the works. Fixes: 52bb7a2166af ("btrfs: introduce size class to block group allocator") CC: stable(a)vger.kernel.org # 6.1+ Reported-by: David Sterba <dsterba(a)suse.com> Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: Boris Burkov <boris(a)bur.io> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 85833bf216de..97d517cdf2df 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3651,6 +3651,21 @@ btrfs_release_block_group(struct btrfs_block_group *cache, btrfs_put_block_group(cache); } +static bool find_free_extent_check_size_class(const struct find_free_extent_ctl *ffe_ctl, + const struct btrfs_block_group *bg) +{ + if (ffe_ctl->policy == BTRFS_EXTENT_ALLOC_ZONED) + return true; + if (!btrfs_block_group_should_use_size_class(bg)) + return true; + if (ffe_ctl->loop >= LOOP_WRONG_SIZE_CLASS) + return true; + if (ffe_ctl->loop >= LOOP_UNSET_SIZE_CLASS && + bg->size_class == BTRFS_BG_SZ_NONE) + return true; + return ffe_ctl->size_class == bg->size_class; +} + /* * Helper function for find_free_extent(). * @@ -3672,7 +3687,8 @@ static int find_free_extent_clustered(struct btrfs_block_group *bg, if (!cluster_bg) goto refill_cluster; if (cluster_bg != bg && (cluster_bg->ro || - !block_group_bits(cluster_bg, ffe_ctl->flags))) + !block_group_bits(cluster_bg, ffe_ctl->flags) || + !find_free_extent_check_size_class(ffe_ctl, cluster_bg))) goto release_cluster; offset = btrfs_alloc_from_cluster(cluster_bg, last_ptr, @@ -4229,21 +4245,6 @@ static int find_free_extent_update_loop(struct btrfs_fs_info *fs_info, return -ENOSPC; } -static bool find_free_extent_check_size_class(struct find_free_extent_ctl *ffe_ctl, - struct btrfs_block_group *bg) -{ - if (ffe_ctl->policy == BTRFS_EXTENT_ALLOC_ZONED) - return true; - if (!btrfs_block_group_should_use_size_class(bg)) - return true; - if (ffe_ctl->loop >= LOOP_WRONG_SIZE_CLASS) - return true; - if (ffe_ctl->loop >= LOOP_UNSET_SIZE_CLASS && - bg->size_class == BTRFS_BG_SZ_NONE) - return true; - return ffe_ctl->size_class == bg->size_class; -} - static int prepare_allocation_clustered(struct btrfs_fs_info *fs_info, struct find_free_extent_ctl *ffe_ctl, struct btrfs_space_info *space_info,

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[PATCH 5.4.y] ACPI: processor: idle: Check acpi_bus_get_device return value

by Yann Sionneau

From: Teddy Astie <teddy.astie(a)vates.tech> [ Upstream commit 2437513a814b3e93bd02879740a8a06e52e2cf7d ] Fix a potential NULL pointer dereferences if acpi_bus_get_device happens to fail. This is backported from commit 2437513a814b3 ("ACPI: processor: idle: Check acpi_fetch_acpi_dev() return value") This has been tested successfully by the reporter, see https://xcp-ng.org/forum/topic/10972/xcp-ng-8.3-lts-install-on-minisforum-m… Signed-off-by: Li Zhong <floridsleeves(a)gmail.com> Signed-off-by: Teddy Astie <teddy.astie(a)vates.tech> Signed-off-by: Yann Sionneau <yann.sionneau(a)vates.tech> Reported-by: Dillon C <dchan(a)dchan.tech> Tested-by: Dillon C <dchan(a)dchan.tech> --- drivers/acpi/processor_idle.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 92db8b0622b2..e6bba26caf3c 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -1228,7 +1228,9 @@ static int acpi_processor_get_lpi_info(struct acpi_processor *pr) status = acpi_get_parent(handle, &pr_ahandle); while (ACPI_SUCCESS(status)) { - acpi_bus_get_device(pr_ahandle, &d); + if (acpi_bus_get_device(pr_ahandle, &d)) + break; + handle = pr_ahandle; if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID)) base-commit: 04b7726c3cdd2fb4da040c2b898bcf405ed607bd -- 2.43.0 Yann Sionneau | Vates XCP-ng Developer XCP-ng & Xen Orchestra - Vates solutions web: https://vates.tech

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