May 2025 - Linux-stable-mirror

+ mm-hugetlb-fix-a-deadlock-with-pagecache_folio-and-hugetlb_fault_mutex_table.patch added to mm-new branch

by Andrew Morton

The patch titled Subject: mm/hugetlb: fix a deadlock with pagecache_folio and hugetlb_fault_mutex_table has been added to the -mm mm-new branch. Its filename is mm-hugetlb-fix-a-deadlock-with-pagecache_folio-and-hugetlb_fault_mutex_table.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche… This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Gavin Guo <gavinguo(a)igalia.com> Subject: mm/hugetlb: fix a deadlock with pagecache_folio and hugetlb_fault_mutex_table Date: Tue, 13 May 2025 17:34:48 +0800 Fix a deadlock which can be triggered by an internal syzkaller [1] reproducer and captured by bpftrace script [2] and its log [3] in this scenario: Process 1 Process 2 --- --- hugetlb_fault mutex_lock(B) // take B filemap_lock_hugetlb_folio filemap_lock_folio __filemap_get_folio folio_lock(A) // take A hugetlb_wp mutex_unlock(B) // release B ... hugetlb_fault ... mutex_lock(B) // take B filemap_lock_hugetlb_folio filemap_lock_folio __filemap_get_folio folio_lock(A) // blocked unmap_ref_private ... mutex_lock(B) // retake and blocked This is a ABBA deadlock involving two locks: - Lock A: pagecache_folio lock - Lock B: hugetlb_fault_mutex_table lock The deadlock occurs between two processes as follows: 1. The first process (let's call it Process 1) is handling a copy-on-write (COW) operation on a hugepage via hugetlb_wp. Due to insufficient reserved hugetlb pages, Process 1, owner of the reserved hugetlb page, attempts to unmap a hugepage owned by another process (non-owner) to satisfy the reservation. Before unmapping, Process 1 acquires lock B (hugetlb_fault_mutex_table lock) and then lock A (pagecache_folio lock). To proceed with the unmap, it releases Lock B but retains Lock A. After the unmap, Process 1 tries to reacquire Lock B. However, at this point, Lock B has already been acquired by another process. 2. The second process (Process 2) enters the hugetlb_fault handler during the unmap operation. It successfully acquires Lock B (hugetlb_fault_mutex_table lock) that was just released by Process 1, but then attempts to acquire Lock A (pagecache_folio lock), which is still held by Process 1. As a result, Process 1 (holding Lock A) is blocked waiting for Lock B (held by Process 2), while Process 2 (holding Lock B) is blocked waiting for Lock A (held by Process 1), constructing a ABBA deadlock scenario. The solution here is to unlock the pagecache_folio and provide the pagecache_folio_unlocked variable to the caller to have the visibility over the pagecache_folio status for subsequent handling. The error message: INFO: task repro_20250402_:13229 blocked for more than 64 seconds. Not tainted 6.15.0-rc3+ #24 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:repro_20250402_ state:D stack:25856 pid:13229 tgid:13228 ppid:3513 task_flags:0x400040 flags:0x00004006 Call Trace: <TASK> __schedule+0x1755/0x4f50 schedule+0x158/0x330 schedule_preempt_disabled+0x15/0x30 __mutex_lock+0x75f/0xeb0 hugetlb_wp+0xf88/0x3440 hugetlb_fault+0x14c8/0x2c30 trace_clock_x86_tsc+0x20/0x20 do_user_addr_fault+0x61d/0x1490 exc_page_fault+0x64/0x100 asm_exc_page_fault+0x26/0x30 RIP: 0010:__put_user_4+0xd/0x20 copy_process+0x1f4a/0x3d60 kernel_clone+0x210/0x8f0 __x64_sys_clone+0x18d/0x1f0 do_syscall_64+0x6a/0x120 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x41b26d </TASK> INFO: task repro_20250402_:13229 is blocked on a mutex likely owned by task repro_20250402_:13250. task:repro_20250402_ state:D stack:28288 pid:13250 tgid:13228 ppid:3513 task_flags:0x400040 flags:0x00000006 Call Trace: <TASK> __schedule+0x1755/0x4f50 schedule+0x158/0x330 io_schedule+0x92/0x110 folio_wait_bit_common+0x69a/0xba0 __filemap_get_folio+0x154/0xb70 hugetlb_fault+0xa50/0x2c30 trace_clock_x86_tsc+0x20/0x20 do_user_addr_fault+0xace/0x1490 exc_page_fault+0x64/0x100 asm_exc_page_fault+0x26/0x30 RIP: 0033:0x402619 </TASK> INFO: task repro_20250402_:13250 blocked for more than 65 seconds. Not tainted 6.15.0-rc3+ #24 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:repro_20250402_ state:D stack:28288 pid:13250 tgid:13228 ppid:3513 task_flags:0x400040 flags:0x00000006 Call Trace: <TASK> __schedule+0x1755/0x4f50 schedule+0x158/0x330 io_schedule+0x92/0x110 folio_wait_bit_common+0x69a/0xba0 __filemap_get_folio+0x154/0xb70 hugetlb_fault+0xa50/0x2c30 trace_clock_x86_tsc+0x20/0x20 do_user_addr_fault+0xace/0x1490 exc_page_fault+0x64/0x100 asm_exc_page_fault+0x26/0x30 RIP: 0033:0x402619 </TASK> Showing all locks held in the system: 1 lock held by khungtaskd/35: #0: ffffffff879a7440 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 2 locks held by repro_20250402_/13229: #0: ffff888017d801e0 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x37/0x300 #1: ffff888000fec848 (&hugetlb_fault_mutex_table[i]){+.+.}-{4:4}, at: hugetlb_wp+0xf88/0x3440 3 locks held by repro_20250402_/13250: #0: ffff8880177f3d08 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x41b/0x1490 #1: ffff888000fec848 (&hugetlb_fault_mutex_table[i]){+.+.}-{4:4}, at: hugetlb_fault+0x3b8/0x2c30 #2: ffff8880129500e8 (&resv_map->rw_sema){++++}-{4:4}, at: hugetlb_fault+0x494/0x2c30 Link: https://drive.google.com/file/d/1DVRnIW-vSayU5J1re9Ct_br3jJQU6Vpb/view?usp=… [1] Link: https://github.com/bboymimi/bpftracer/blob/master/scripts/hugetlb_lock_debu… [2] Link: https://drive.google.com/file/d/1bWq2-8o-BJAuhoHWX7zAhI6ggfhVzQUI/view?usp=… [3] Link: https://lkml.kernel.org/r/20250513093448.592150-1-gavinguo@igalia.com Fixes: 40549ba8f8e0 ("hugetlb: use new vma_lock for pmd sharing synchronization") Signed-off-by: Gavin Guo <gavinguo(a)igalia.com> Cc: Hugh Dickins <hughd(a)google.com> Cc: Florent Revest <revest(a)google.com> Cc: Gavin Shan <gshan(a)redhat.com> Cc: Muchun Song <muchun.song(a)linux.dev> Cc: Oscar Salvador <osalvador(a)suse.de> Cc: Byungchul Park <byungchul(a)sk.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/hugetlb.c | 33 ++++++++++++++++++++++++++++----- 1 file changed, 28 insertions(+), 5 deletions(-) --- a/mm/hugetlb.c~mm-hugetlb-fix-a-deadlock-with-pagecache_folio-and-hugetlb_fault_mutex_table +++ a/mm/hugetlb.c @@ -6131,7 +6131,8 @@ static void unmap_ref_private(struct mm_ * Keep the pte_same checks anyway to make transition from the mutex easier. */ static vm_fault_t hugetlb_wp(struct folio *pagecache_folio, - struct vm_fault *vmf) + struct vm_fault *vmf, + bool *pagecache_folio_unlocked) { struct vm_area_struct *vma = vmf->vma; struct mm_struct *mm = vma->vm_mm; @@ -6229,6 +6230,22 @@ retry_avoidcopy: folio_put(old_folio); /* + * The pagecache_folio needs to be unlocked to avoid + * deadlock and we won't re-lock it in hugetlb_wp(). The + * pagecache_folio could be truncated after being + * unlocked. So its state should not be relied + * subsequently. + * + * Setting *pagecache_folio_unlocked to true allows the + * caller to handle any necessary logic related to the + * folio's unlocked state. + */ + if (pagecache_folio) { + folio_unlock(pagecache_folio); + if (pagecache_folio_unlocked) + *pagecache_folio_unlocked = true; + } + /* * Drop hugetlb_fault_mutex and vma_lock before * unmapping. unmapping needs to hold vma_lock * in write mode. Dropping vma_lock in read mode @@ -6581,7 +6598,7 @@ static vm_fault_t hugetlb_no_page(struct hugetlb_count_add(pages_per_huge_page(h), mm); if ((vmf->flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { /* Optimization, do the COW without a second fault */ - ret = hugetlb_wp(folio, vmf); + ret = hugetlb_wp(folio, vmf, NULL); } spin_unlock(vmf->ptl); @@ -6653,6 +6670,7 @@ vm_fault_t hugetlb_fault(struct mm_struc struct hstate *h = hstate_vma(vma); struct address_space *mapping; int need_wait_lock = 0; + bool pagecache_folio_unlocked = false; struct vm_fault vmf = { .vma = vma, .address = address & huge_page_mask(h), @@ -6807,7 +6825,8 @@ vm_fault_t hugetlb_fault(struct mm_struc if (flags & (FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE)) { if (!huge_pte_write(vmf.orig_pte)) { - ret = hugetlb_wp(pagecache_folio, &vmf); + ret = hugetlb_wp(pagecache_folio, &vmf, + &pagecache_folio_unlocked); goto out_put_page; } else if (likely(flags & FAULT_FLAG_WRITE)) { vmf.orig_pte = huge_pte_mkdirty(vmf.orig_pte); @@ -6824,10 +6843,14 @@ out_put_page: out_ptl: spin_unlock(vmf.ptl); - if (pagecache_folio) { + /* + * If the pagecache_folio is unlocked in hugetlb_wp(), we skip + * folio_unlock() here. + */ + if (pagecache_folio && !pagecache_folio_unlocked) folio_unlock(pagecache_folio); + if (pagecache_folio) folio_put(pagecache_folio); - } out_mutex: hugetlb_vma_unlock_read(vma); _ Patches currently in -mm which might be from gavinguo(a)igalia.com are mm-hugetlb-fix-a-deadlock-with-pagecache_folio-and-hugetlb_fault_mutex_table.patch

6 months

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[PATCH net v2] net: dsa: microchip: linearize skb for tail-tagging switches

by Jakob Unterwurzacher

The pointer arithmentic for accessing the tail tag only works for linear skbs. For nonlinear skbs, it reads uninitialized memory inside the skb headroom, essentially randomizing the tag. I have observed it gets set to 6 most of the time. Example where ksz9477_rcv thinks that the packet from port 1 comes from port 6 (which does not exist for the ksz9896 that's in use), dropping the packet. Debug prints added by me (not included in this patch): [ 256.645337] ksz9477_rcv:323 tag0=6 [ 256.645349] skb len=47 headroom=78 headlen=0 tailroom=0 mac=(64,14) mac_len=14 net=(78,0) trans=78 shinfo(txflags=0 nr_frags=1 gso(size=0 type=0 segs=0)) csum(0x0 start=0 offset=0 ip_summed=0 complete_sw=0 valid=0 level=0) hash(0x0 sw=0 l4=0) proto=0x00f8 pkttype=1 iif=3 priority=0x0 mark=0x0 alloc_cpu=0 vlan_all=0x0 encapsulation=0 inner(proto=0x0000, mac=0, net=0, trans=0) [ 256.645377] dev name=end1 feat=0x0002e10200114bb3 [ 256.645386] skb headroom: 00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 256.645395] skb headroom: 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 256.645403] skb headroom: 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 256.645411] skb headroom: 00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 256.645420] skb headroom: 00000040: ff ff ff ff ff ff 00 1c 19 f2 e2 db 08 06 [ 256.645428] skb frag: 00000000: 00 01 08 00 06 04 00 01 00 1c 19 f2 e2 db 0a 02 [ 256.645436] skb frag: 00000010: 00 83 00 00 00 00 00 00 0a 02 a0 2f 00 00 00 00 [ 256.645444] skb frag: 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 [ 256.645452] ksz_common_rcv:92 dsa_conduit_find_user returned NULL Call skb_linearize before trying to access the tag. This patch fixes ksz9477_rcv which is used by the ksz9896 I have at hand, and also applies the same fix to ksz8795_rcv which seems to have the same problem. Signed-off-by: Jakob Unterwurzacher <jakob.unterwurzacher(a)cherry.de> Cc: stable(a)vger.kernel.org Fixes: 016e43a26bab ("net: dsa: ksz: Add KSZ8795 tag code") Fixes: 8b8010fb7876 ("dsa: add support for Microchip KSZ tail tagging) --- v1: https://lore.kernel.org/netdev/20250509071820.4100022-1-jakob.unterwurzache… v2: add Fixes tags, Cc stable, "[PATCH net]" prefix net/dsa/tag_ksz.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c index 281bbac5539d..55ef093fe66b 100644 --- a/net/dsa/tag_ksz.c +++ b/net/dsa/tag_ksz.c @@ -140,7 +140,12 @@ static struct sk_buff *ksz8795_xmit(struct sk_buff *skb, struct net_device *dev) static struct sk_buff *ksz8795_rcv(struct sk_buff *skb, struct net_device *dev) { - u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN; + u8 *tag; + + if (skb_linearize(skb)) + return NULL; + + tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN; return ksz_common_rcv(skb, dev, tag[0] & KSZ8795_TAIL_TAG_EG_PORT_M, KSZ_EGRESS_TAG_LEN); @@ -311,8 +316,13 @@ static struct sk_buff *ksz9477_xmit(struct sk_buff *skb, static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev) { + u8 *tag; + + if (skb_linearize(skb)) + return NULL; + /* Tag decoding */ - u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN; + tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN; unsigned int port = tag[0] & KSZ9477_TAIL_TAG_EG_PORT_M; unsigned int len = KSZ_EGRESS_TAG_LEN; -- 2.39.5

6 months

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[STABLE 5.10 5.15] ice: arfs: fix use-after-free when freeing @rx_cpu_rmap

by Suraj Jitindar Singh

From: Alexander Lobakin <alexandr.lobakin(a)intel.com> [ Upstream commit d7442f512b71fc63a99c8a801422dde4fbbf9f93 ] The CI testing bots triggered the following splat: [ 718.203054] BUG: KASAN: use-after-free in free_irq_cpu_rmap+0x53/0x80 [ 718.206349] Read of size 4 at addr ffff8881bd127e00 by task sh/20834 [ 718.212852] CPU: 28 PID: 20834 Comm: sh Kdump: loaded Tainted: G S W IOE 5.17.0-rc8_nextqueue-devqueue-02643-g23f3121aca93 #1 [ 718.219695] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0012.070720200218 07/07/2020 [ 718.223418] Call Trace: [ 718.227139] [ 718.230783] dump_stack_lvl+0x33/0x42 [ 718.234431] print_address_description.constprop.9+0x21/0x170 [ 718.238177] ? free_irq_cpu_rmap+0x53/0x80 [ 718.241885] ? free_irq_cpu_rmap+0x53/0x80 [ 718.245539] kasan_report.cold.18+0x7f/0x11b [ 718.249197] ? free_irq_cpu_rmap+0x53/0x80 [ 718.252852] free_irq_cpu_rmap+0x53/0x80 [ 718.256471] ice_free_cpu_rx_rmap.part.11+0x37/0x50 [ice] [ 718.260174] ice_remove_arfs+0x5f/0x70 [ice] [ 718.263810] ice_rebuild_arfs+0x3b/0x70 [ice] [ 718.267419] ice_rebuild+0x39c/0xb60 [ice] [ 718.270974] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 718.274472] ? ice_init_phy_user_cfg+0x360/0x360 [ice] [ 718.278033] ? delay_tsc+0x4a/0xb0 [ 718.281513] ? preempt_count_sub+0x14/0xc0 [ 718.284984] ? delay_tsc+0x8f/0xb0 [ 718.288463] ice_do_reset+0x92/0xf0 [ice] [ 718.292014] ice_pci_err_resume+0x91/0xf0 [ice] [ 718.295561] pci_reset_function+0x53/0x80 <...> [ 718.393035] Allocated by task 690: [ 718.433497] Freed by task 20834: [ 718.495688] Last potentially related work creation: [ 718.568966] The buggy address belongs to the object at ffff8881bd127e00 which belongs to the cache kmalloc-96 of size 96 [ 718.574085] The buggy address is located 0 bytes inside of 96-byte region [ffff8881bd127e00, ffff8881bd127e60) [ 718.579265] The buggy address belongs to the page: [ 718.598905] Memory state around the buggy address: [ 718.601809] ffff8881bd127d00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 718.604796] ffff8881bd127d80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc [ 718.607794] >ffff8881bd127e00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 718.610811] ^ [ 718.613819] ffff8881bd127e80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 718.617107] ffff8881bd127f00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc This is due to that free_irq_cpu_rmap() is always being called *after* (devm_)free_irq() and thus it tries to work with IRQ descs already freed. For example, on device reset the driver frees the rmap right before allocating a new one (the splat above). Make rmap creation and freeing function symmetrical with {request,free}_irq() calls i.e. do that on ifup/ifdown instead of device probe/remove/resume. These operations can be performed independently from the actual device aRFS configuration. Also, make sure ice_vsi_free_irq() clears IRQ affinity notifiers only when aRFS is disabled -- otherwise, CPU rmap sets and clears its own and they must not be touched manually. Fixes: 28bf26724fdb0 ("ice: Implement aRFS") Co-developed-by: Ivan Vecera <ivecera(a)redhat.com> Signed-off-by: Ivan Vecera <ivecera(a)redhat.com> Signed-off-by: Alexander Lobakin <alexandr.lobakin(a)intel.com> Tested-by: Ivan Vecera <ivecera(a)redhat.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen(a)intel.com> Cc: <stable(a)vger.kernel.org> # 5.10.x Cc: <stable(a)vger.kernel.org> # 5.15.x Signed-off-by: Suraj Jitindar Singh <surajjs(a)amazon.com> --- drivers/net/ethernet/intel/ice/ice_arfs.c | 9 ++------- drivers/net/ethernet/intel/ice/ice_lib.c | 5 ++++- drivers/net/ethernet/intel/ice/ice_main.c | 20 ++++++++------------ 3 files changed, 14 insertions(+), 20 deletions(-) diff --git a/drivers/net/ethernet/intel/ice/ice_arfs.c b/drivers/net/ethernet/intel/ice/ice_arfs.c index 632f16ffee40..085b1a0d67c5 100644 --- a/drivers/net/ethernet/intel/ice/ice_arfs.c +++ b/drivers/net/ethernet/intel/ice/ice_arfs.c @@ -577,7 +577,7 @@ void ice_free_cpu_rx_rmap(struct ice_vsi *vsi) { struct net_device *netdev; - if (!vsi || vsi->type != ICE_VSI_PF || !vsi->arfs_fltr_list) + if (!vsi || vsi->type != ICE_VSI_PF) return; netdev = vsi->netdev; @@ -600,7 +600,7 @@ int ice_set_cpu_rx_rmap(struct ice_vsi *vsi) int base_idx, i; if (!vsi || vsi->type != ICE_VSI_PF) - return -EINVAL; + return 0; pf = vsi->back; netdev = vsi->netdev; @@ -638,7 +638,6 @@ void ice_remove_arfs(struct ice_pf *pf) if (!pf_vsi) return; - ice_free_cpu_rx_rmap(pf_vsi); ice_clear_arfs(pf_vsi); } @@ -655,9 +654,5 @@ void ice_rebuild_arfs(struct ice_pf *pf) return; ice_remove_arfs(pf); - if (ice_set_cpu_rx_rmap(pf_vsi)) { - dev_err(ice_pf_to_dev(pf), "Failed to rebuild aRFS\n"); - return; - } ice_init_arfs(pf_vsi); } diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c index e99c8c10bc61..d3e5bf180c37 100644 --- a/drivers/net/ethernet/intel/ice/ice_lib.c +++ b/drivers/net/ethernet/intel/ice/ice_lib.c @@ -2411,6 +2411,8 @@ void ice_vsi_free_irq(struct ice_vsi *vsi) return; vsi->irqs_ready = false; + ice_free_cpu_rx_rmap(vsi); + ice_for_each_q_vector(vsi, i) { u16 vector = i + base; int irq_num; @@ -2424,7 +2426,8 @@ void ice_vsi_free_irq(struct ice_vsi *vsi) continue; /* clear the affinity notifier in the IRQ descriptor */ - irq_set_affinity_notifier(irq_num, NULL); + if (!IS_ENABLED(CONFIG_RFS_ACCEL)) + irq_set_affinity_notifier(irq_num, NULL); /* clear the affinity_mask in the IRQ descriptor */ irq_set_affinity_hint(irq_num, NULL); diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c index 035bc90c8124..a337a6826a84 100644 --- a/drivers/net/ethernet/intel/ice/ice_main.c +++ b/drivers/net/ethernet/intel/ice/ice_main.c @@ -2247,6 +2247,13 @@ static int ice_vsi_req_irq_msix(struct ice_vsi *vsi, char *basename) irq_set_affinity_hint(irq_num, &q_vector->affinity_mask); } + err = ice_set_cpu_rx_rmap(vsi); + if (err) { + netdev_err(vsi->netdev, "Failed to setup CPU RMAP on VSI %u: %pe\n", + vsi->vsi_num, ERR_PTR(err)); + goto free_q_irqs; + } + vsi->irqs_ready = true; return 0; @@ -3242,22 +3249,12 @@ static int ice_setup_pf_sw(struct ice_pf *pf) */ ice_napi_add(vsi); - status = ice_set_cpu_rx_rmap(vsi); - if (status) { - dev_err(ice_pf_to_dev(pf), "Failed to set CPU Rx map VSI %d error %d\n", - vsi->vsi_num, status); - status = -EINVAL; - goto unroll_napi_add; - } status = ice_init_mac_fltr(pf); if (status) - goto free_cpu_rx_map; + goto unroll_napi_add; return status; -free_cpu_rx_map: - ice_free_cpu_rx_rmap(vsi); - unroll_napi_add: if (vsi) { ice_napi_del(vsi); @@ -4598,7 +4595,6 @@ static int __maybe_unused ice_suspend(struct device *dev) continue; ice_vsi_free_q_vectors(pf->vsi[v]); } - ice_free_cpu_rx_rmap(ice_get_main_vsi(pf)); ice_clear_interrupt_scheme(pf); pci_save_state(pdev); -- 2.47.1

6 months

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[PATCH v4] drm/amdgpu: read back register after written for VCN v4.0.5

by David (Ming Qiang) Wu

V4: add read-back for non-DPG case. This is for protection purpose as it is not used for producton. On VCN v4.0.5 there is a race condition where the WPTR is not updated after starting from idle when doorbell is used. Adding register read-back after written at function end is to ensure all register writes are done before they can be used. Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/12528 Cc: stable(a)vger.kernel.org Signed-off-by: David (Ming Qiang) Wu <David.Wu3(a)amd.com> Reviewed-by: Mario Limonciello <mario.limonciello(a)amd.com> Tested-by: Mario Limonciello <mario.limonciello(a)amd.com> --- drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c index ed00d35039c1..a09f9a2dd471 100644 --- a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c +++ b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c @@ -1034,6 +1034,10 @@ static int vcn_v4_0_5_start_dpg_mode(struct amdgpu_vcn_inst *vinst, ring->doorbell_index << VCN_RB1_DB_CTRL__OFFSET__SHIFT | VCN_RB1_DB_CTRL__EN_MASK); + /* Keeping one read-back to ensure all register writes are done, otherwise + * it may introduce race conditions */ + RREG32_SOC15(VCN, inst_idx, regVCN_RB1_DB_CTRL); + return 0; } @@ -1216,6 +1220,10 @@ static int vcn_v4_0_5_start(struct amdgpu_vcn_inst *vinst) WREG32_SOC15(VCN, i, regVCN_RB_ENABLE, tmp); fw_shared->sq.queue_mode &= ~(FW_QUEUE_RING_RESET | FW_QUEUE_DPG_HOLD_OFF); + /* Keeping one read-back to ensure all register writes are done, otherwise + * it may introduce race conditions */ + RREG32_SOC15(VCN, i, regVCN_RB_ENABLE); + return 0; } -- 2.34.1

6 months

1
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[PATCH] x86/its: Fix build errors when CONFIG_MODULES=n

by Eric Biggers

From: Eric Biggers <ebiggers(a)google.com> Fix several build errors when CONFIG_MODULES=n, including the following: ../arch/x86/kernel/alternative.c:195:25: error: incomplete definition of type 'struct module' 195 | for (int i = 0; i < mod->its_num_pages; i++) { Fixes: 872df34d7c51 ("x86/its: Use dynamic thunks for indirect branches") Cc: stable(a)vger.kernel.org Signed-off-by: Eric Biggers <ebiggers(a)google.com> --- arch/x86/kernel/alternative.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 48fd04e90114..45bcff181cba 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -131,11 +131,13 @@ const unsigned char * const x86_nops[ASM_NOP_MAX+1] = static bool cfi_paranoid __ro_after_init; #endif #ifdef CONFIG_MITIGATION_ITS +#ifdef CONFIG_MODULES static struct module *its_mod; +#endif static void *its_page; static unsigned int its_offset; /* Initialize a thunk with the "jmp *reg; int3" instructions. */ static void *its_init_thunk(void *thunk, int reg) @@ -169,10 +171,11 @@ static void *its_init_thunk(void *thunk, int reg) bytes[i++] = 0xcc; return thunk + offset; } +#ifdef CONFIG_MODULES void its_init_mod(struct module *mod) { if (!cpu_feature_enabled(X86_FEATURE_INDIRECT_THUNK_ITS)) return; @@ -207,18 +210,20 @@ void its_free_mod(struct module *mod) void *page = mod->its_page_array[i]; execmem_free(page); } kfree(mod->its_page_array); } +#endif /* CONFIG_MODULES */ static void *its_alloc(void) { void *page __free(execmem) = execmem_alloc(EXECMEM_MODULE_TEXT, PAGE_SIZE); if (!page) return NULL; +#ifdef CONFIG_MODULES if (its_mod) { void *tmp = krealloc(its_mod->its_page_array, (its_mod->its_num_pages+1) * sizeof(void *), GFP_KERNEL); if (!tmp) @@ -227,10 +232,11 @@ static void *its_alloc(void) its_mod->its_page_array = tmp; its_mod->its_page_array[its_mod->its_num_pages++] = page; execmem_make_temp_rw(page, PAGE_SIZE); } +#endif /* CONFIG_MODULES */ return no_free_ptr(page); } static void *its_allocate_thunk(int reg) base-commit: 627277ba7c2398dc4f95cc9be8222bb2d9477800 -- 2.49.0

6 months

6
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[PATCH] dt-bindings: remoteproc: qcom,sm8150-pas: Add missing SC8180X compatible

by Krzysztof Kozlowski

Commit 4b4ab93ddc5f ("dt-bindings: remoteproc: Consolidate SC8180X and SM8150 PAS files") moved SC8180X bindings from separate file into this one, but it forgot to add actual compatibles in top-level properties section making the entire binding un-selectable (no-op) for SC8180X PAS. Fixes: 4b4ab93ddc5f ("dt-bindings: remoteproc: Consolidate SC8180X and SM8150 PAS files") Cc: <stable(a)vger.kernel.org> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski(a)linaro.org> --- .../devicetree/bindings/remoteproc/qcom,sm8150-pas.yaml | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Documentation/devicetree/bindings/remoteproc/qcom,sm8150-pas.yaml b/Documentation/devicetree/bindings/remoteproc/qcom,sm8150-pas.yaml index 56ff6386534d..5dcc2a32c080 100644 --- a/Documentation/devicetree/bindings/remoteproc/qcom,sm8150-pas.yaml +++ b/Documentation/devicetree/bindings/remoteproc/qcom,sm8150-pas.yaml @@ -16,6 +16,9 @@ description: properties: compatible: enum: + - qcom,sc8180x-adsp-pas + - qcom,sc8180x-cdsp-pas + - qcom,sc8180x-slpi-pas - qcom,sm8150-adsp-pas - qcom,sm8150-cdsp-pas - qcom,sm8150-mpss-pas -- 2.45.2

6 months

3
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[PATCH 0/7] pinctrl: armada-37xx: a couple of small fixes

by Gabor Juhos

The series contains several small patches to fix various issues in the pinctrl driver for Armada 3700. Signed-off-by: Gabor Juhos <j4g8y7(a)gmail.com> --- Gabor Juhos (7): pinctrl: armada-37xx: use correct OUTPUT_VAL register for GPIOs > 31 pinctrl: armada-37xx: propagate error from armada_37xx_gpio_direction_output() pinctrl: armada-37xx: set GPIO output value before setting direction pinctrl: armada-37xx: propagate error from armada_37xx_gpio_get() pinctrl: armada-37xx: propagate error from armada_37xx_pmx_gpio_set_direction() pinctrl: armada-37xx: propagate error from armada_37xx_gpio_get_direction() pinctrl: armada-37xx: propagate error from armada_37xx_pmx_set_by_name() drivers/pinctrl/mvebu/pinctrl-armada-37xx.c | 35 ++++++++++++++++------------- 1 file changed, 20 insertions(+), 15 deletions(-) --- base-commit: 82f2b0b97b36ee3fcddf0f0780a9a0825d52fec3 change-id: 20250512-pinctrl-a37xx-fixes-98fabc45cb11 Best regards, -- Gabor Juhos <j4g8y7(a)gmail.com>

6 months

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[PATCH v3 1/3] drm/amdgpu: read back register after written for VCN v4.0.5

by David (Ming Qiang) Wu

V2: not to add extra read-back in vcn_v4_0_5_start as there is a read-back already. New comment for better understanding. On VCN v4.0.5 there is a race condition where the WPTR is not updated after starting from idle when doorbell is used. The read-back of regVCN_RB1_DB_CTRL register after written is to ensure the doorbell_index is updated before it can work properly. Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/12528 Cc: stable(a)vger.kernel.org Signed-off-by: David (Ming Qiang) Wu <David.Wu3(a)amd.com> Reviewed-by: Mario Limonciello <mario.limonciello(a)amd.com> Tested-by: Mario Limonciello <mario.limonciello(a)amd.com> Reviewed-by: Alex Deucher <alexander.deucher(a)amd.com> --- drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c index ed00d35039c1..e55b76d71367 100644 --- a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c +++ b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c @@ -1034,6 +1034,10 @@ static int vcn_v4_0_5_start_dpg_mode(struct amdgpu_vcn_inst *vinst, ring->doorbell_index << VCN_RB1_DB_CTRL__OFFSET__SHIFT | VCN_RB1_DB_CTRL__EN_MASK); + /* Keeping one read-back to ensure all register writes are done, otherwise + * it may introduce race conditions */ + RREG32_SOC15(VCN, inst_idx, regVCN_RB1_DB_CTRL); + return 0; } -- 2.34.1

6 months

1
0
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[PATCH 5.15.y] wifi: cfg80211: check A-MSDU format more carefully

by jianqi.ren.cn＠windriver.com

From: Johannes Berg <johannes.berg(a)intel.com> [ Upstream commit 9ad7974856926129f190ffbe3beea78460b3b7cc ] If it looks like there's another subframe in the A-MSDU but the header isn't fully there, we can end up reading data out of bounds, only to discard later. Make this a bit more careful and check if the subframe header can even be present. Reported-by: syzbot+d050d437fe47d479d210(a)syzkaller.appspotmail.com Link: https://msgid.link/20240226203405.a731e2c95e38.I82ce7d8c0cc8970ce29d0a39fdc… Signed-off-by: Johannes Berg <johannes.berg(a)intel.com> [Minor conflict resolved due to code context change. And routine ieee80211_is_valid_amsdu is introduced by commit fe4a6d2db3ba ("wifi: mac80211: implement support for yet another mesh A-MSDU format") after 6.4.] Signed-off-by: Jianqi Ren <jianqi.ren.cn(a)windriver.com> Signed-off-by: He Zhe <zhe.he(a)windriver.com> --- Verified the build test --- net/wireless/util.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/wireless/util.c b/net/wireless/util.c index 6ebc6567b287..0fd48361e3e1 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -751,24 +751,27 @@ void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list, struct sk_buff *frame = NULL; u16 ethertype; u8 *payload; - int offset = 0, remaining; + int offset = 0; struct ethhdr eth; bool reuse_frag = skb->head_frag && !skb_has_frag_list(skb); bool reuse_skb = false; bool last = false; while (!last) { + int remaining = skb->len - offset; unsigned int subframe_len; int len; u8 padding; + if (sizeof(eth) > remaining) + goto purge; + skb_copy_bits(skb, offset, &eth, sizeof(eth)); len = ntohs(eth.h_proto); subframe_len = sizeof(struct ethhdr) + len; padding = (4 - subframe_len) & 0x3; /* the last MSDU has no padding */ - remaining = skb->len - offset; if (subframe_len > remaining) goto purge; /* mitigate A-MSDU aggregation injection attacks */ -- 2.34.1

6 months

2
1
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[PATCH 5.10.y] btrfs: get rid of warning on transaction commit when using flushoncommit

by Zhi Yang

From: Filipe Manana <fdmanana(a)suse.com> commit a0f0cf8341e34e5d2265bfd3a7ad68342da1e2aa upstream. When using the flushoncommit mount option, during almost every transaction commit we trigger a warning from __writeback_inodes_sb_nr(): $ cat fs/fs-writeback.c: (...) static void __writeback_inodes_sb_nr(struct super_block *sb, ... { (...) WARN_ON(!rwsem_is_locked(&sb->s_umount)); (...) } (...) The trace produced in dmesg looks like the following: [947.473890] WARNING: CPU: 5 PID: 930 at fs/fs-writeback.c:2610 __writeback_inodes_sb_nr+0x7e/0xb3 [947.481623] Modules linked in: nfsd nls_cp437 cifs asn1_decoder cifs_arc4 fscache cifs_md4 ipmi_ssif [947.489571] CPU: 5 PID: 930 Comm: btrfs-transacti Not tainted 95.16.3-srb-asrock-00001-g36437ad63879 #186 [947.497969] RIP: 0010:__writeback_inodes_sb_nr+0x7e/0xb3 [947.502097] Code: 24 10 4c 89 44 24 18 c6 (...) [947.519760] RSP: 0018:ffffc90000777e10 EFLAGS: 00010246 [947.523818] RAX: 0000000000000000 RBX: 0000000000963300 RCX: 0000000000000000 [947.529765] RDX: 0000000000000000 RSI: 000000000000fa51 RDI: ffffc90000777e50 [947.535740] RBP: ffff888101628a90 R08: ffff888100955800 R09: ffff888100956000 [947.541701] R10: 0000000000000002 R11: 0000000000000001 R12: ffff888100963488 [947.547645] R13: ffff888100963000 R14: ffff888112fb7200 R15: ffff888100963460 [947.553621] FS: 0000000000000000(0000) GS:ffff88841fd40000(0000) knlGS:0000000000000000 [947.560537] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [947.565122] CR2: 0000000008be50c4 CR3: 000000000220c000 CR4: 00000000001006e0 [947.571072] Call Trace: [947.572354] <TASK> [947.573266] btrfs_commit_transaction+0x1f1/0x998 [947.576785] ? start_transaction+0x3ab/0x44e [947.579867] ? schedule_timeout+0x8a/0xdd [947.582716] transaction_kthread+0xe9/0x156 [947.585721] ? btrfs_cleanup_transaction.isra.0+0x407/0x407 [947.590104] kthread+0x131/0x139 [947.592168] ? set_kthread_struct+0x32/0x32 [947.595174] ret_from_fork+0x22/0x30 [947.597561] </TASK> [947.598553] ---[ end trace 644721052755541c ]--- This is because we started using writeback_inodes_sb() to flush delalloc when committing a transaction (when using -o flushoncommit), in order to avoid deadlocks with filesystem freeze operations. This change was made by commit ce8ea7cc6eb313 ("btrfs: don't call btrfs_start_delalloc_roots in flushoncommit"). After that change we started producing that warning, and every now and then a user reports this since the warning happens too often, it spams dmesg/syslog, and a user is unsure if this reflects any problem that might compromise the filesystem's reliability. We can not just lock the sb->s_umount semaphore before calling writeback_inodes_sb(), because that would at least deadlock with filesystem freezing, since at fs/super.c:freeze_super() sync_filesystem() is called while we are holding that semaphore in write mode, and that can trigger a transaction commit, resulting in a deadlock. It would also trigger the same type of deadlock in the unmount path. Possibly, it could also introduce some other locking dependencies that lockdep would report. To fix this call try_to_writeback_inodes_sb() instead of writeback_inodes_sb(), because that will try to read lock sb->s_umount and then will only call writeback_inodes_sb() if it was able to lock it. This is fine because the cases where it can't read lock sb->s_umount are during a filesystem unmount or during a filesystem freeze - in those cases sb->s_umount is write locked and sync_filesystem() is called, which calls writeback_inodes_sb(). In other words, in all cases where we can't take a read lock on sb->s_umount, writeback is already being triggered elsewhere. An alternative would be to call btrfs_start_delalloc_roots() with a number of pages different from LONG_MAX, for example matching the number of delalloc bytes we currently have, in which case we would end up starting all delalloc with filemap_fdatawrite_wbc() and not with an async flush via filemap_flush() - that is only possible after the rather recent commit e076ab2a2ca70a ("btrfs: shrink delalloc pages instead of full inodes"). However that creates a whole new can of worms due to new lock dependencies, which lockdep complains, like for example: [ 8948.247280] ====================================================== [ 8948.247823] WARNING: possible circular locking dependency detected [ 8948.248353] 5.17.0-rc1-btrfs-next-111 #1 Not tainted [ 8948.248786] ------------------------------------------------------ [ 8948.249320] kworker/u16:18/933570 is trying to acquire lock: [ 8948.249812] ffff9b3de1591690 (sb_internal#2){.+.+}-{0:0}, at: find_free_extent+0x141e/0x1590 [btrfs] [ 8948.250638] but task is already holding lock: [ 8948.251140] ffff9b3e09c717d8 (&root->delalloc_mutex){+.+.}-{3:3}, at: start_delalloc_inodes+0x78/0x400 [btrfs] [ 8948.252018] which lock already depends on the new lock. [ 8948.252710] the existing dependency chain (in reverse order) is: [ 8948.253343] -> #2 (&root->delalloc_mutex){+.+.}-{3:3}: [ 8948.253950] __mutex_lock+0x90/0x900 [ 8948.254354] start_delalloc_inodes+0x78/0x400 [btrfs] [ 8948.254859] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs] [ 8948.255408] btrfs_commit_transaction+0x32f/0xc00 [btrfs] [ 8948.255942] btrfs_mksubvol+0x380/0x570 [btrfs] [ 8948.256406] btrfs_mksnapshot+0x81/0xb0 [btrfs] [ 8948.256870] __btrfs_ioctl_snap_create+0x17f/0x190 [btrfs] [ 8948.257413] btrfs_ioctl_snap_create_v2+0xbb/0x140 [btrfs] [ 8948.257961] btrfs_ioctl+0x1196/0x3630 [btrfs] [ 8948.258418] __x64_sys_ioctl+0x83/0xb0 [ 8948.258793] do_syscall_64+0x3b/0xc0 [ 8948.259146] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 8948.259709] -> #1 (&fs_info->delalloc_root_mutex){+.+.}-{3:3}: [ 8948.260330] __mutex_lock+0x90/0x900 [ 8948.260692] btrfs_start_delalloc_roots+0x97/0x2a0 [btrfs] [ 8948.261234] btrfs_commit_transaction+0x32f/0xc00 [btrfs] [ 8948.261766] btrfs_set_free_space_cache_v1_active+0x38/0x60 [btrfs] [ 8948.262379] btrfs_start_pre_rw_mount+0x119/0x180 [btrfs] [ 8948.262909] open_ctree+0x1511/0x171e [btrfs] [ 8948.263359] btrfs_mount_root.cold+0x12/0xde [btrfs] [ 8948.263863] legacy_get_tree+0x30/0x50 [ 8948.264242] vfs_get_tree+0x28/0xc0 [ 8948.264594] vfs_kern_mount.part.0+0x71/0xb0 [ 8948.265017] btrfs_mount+0x11d/0x3a0 [btrfs] [ 8948.265462] legacy_get_tree+0x30/0x50 [ 8948.265851] vfs_get_tree+0x28/0xc0 [ 8948.266203] path_mount+0x2d4/0xbe0 [ 8948.266554] __x64_sys_mount+0x103/0x140 [ 8948.266940] do_syscall_64+0x3b/0xc0 [ 8948.267300] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 8948.267790] -> #0 (sb_internal#2){.+.+}-{0:0}: [ 8948.268322] __lock_acquire+0x12e8/0x2260 [ 8948.268733] lock_acquire+0xd7/0x310 [ 8948.269092] start_transaction+0x44c/0x6e0 [btrfs] [ 8948.269591] find_free_extent+0x141e/0x1590 [btrfs] [ 8948.270087] btrfs_reserve_extent+0x14b/0x280 [btrfs] [ 8948.270588] cow_file_range+0x17e/0x490 [btrfs] [ 8948.271051] btrfs_run_delalloc_range+0x345/0x7a0 [btrfs] [ 8948.271586] writepage_delalloc+0xb5/0x170 [btrfs] [ 8948.272071] __extent_writepage+0x156/0x3c0 [btrfs] [ 8948.272579] extent_write_cache_pages+0x263/0x460 [btrfs] [ 8948.273113] extent_writepages+0x76/0x130 [btrfs] [ 8948.273573] do_writepages+0xd2/0x1c0 [ 8948.273942] filemap_fdatawrite_wbc+0x68/0x90 [ 8948.274371] start_delalloc_inodes+0x17f/0x400 [btrfs] [ 8948.274876] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs] [ 8948.275417] flush_space+0x1f2/0x630 [btrfs] [ 8948.275863] btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs] [ 8948.276438] process_one_work+0x252/0x5a0 [ 8948.276829] worker_thread+0x55/0x3b0 [ 8948.277189] kthread+0xf2/0x120 [ 8948.277506] ret_from_fork+0x22/0x30 [ 8948.277868] other info that might help us debug this: [ 8948.278548] Chain exists of: sb_internal#2 --> &fs_info->delalloc_root_mutex --> &root->delalloc_mutex [ 8948.279601] Possible unsafe locking scenario: [ 8948.280102] CPU0 CPU1 [ 8948.280508] ---- ---- [ 8948.280915] lock(&root->delalloc_mutex); [ 8948.281271] lock(&fs_info->delalloc_root_mutex); [ 8948.281915] lock(&root->delalloc_mutex); [ 8948.282487] lock(sb_internal#2); [ 8948.282800] *** DEADLOCK *** [ 8948.283333] 4 locks held by kworker/u16:18/933570: [ 8948.283750] #0: ffff9b3dc00a9d48 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1d2/0x5a0 [ 8948.284609] #1: ffffa90349dafe70 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: process_one_work+0x1d2/0x5a0 [ 8948.285637] #2: ffff9b3e14db5040 (&fs_info->delalloc_root_mutex){+.+.}-{3:3}, at: btrfs_start_delalloc_roots+0x97/0x2a0 [btrfs] [ 8948.286674] #3: ffff9b3e09c717d8 (&root->delalloc_mutex){+.+.}-{3:3}, at: start_delalloc_inodes+0x78/0x400 [btrfs] [ 8948.287596] stack backtrace: [ 8948.287975] CPU: 3 PID: 933570 Comm: kworker/u16:18 Not tainted 5.17.0-rc1-btrfs-next-111 #1 [ 8948.288677] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 8948.289649] Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs] [ 8948.290298] Call Trace: [ 8948.290517] <TASK> [ 8948.290700] dump_stack_lvl+0x59/0x73 [ 8948.291026] check_noncircular+0xf3/0x110 [ 8948.291375] ? start_transaction+0x228/0x6e0 [btrfs] [ 8948.291826] __lock_acquire+0x12e8/0x2260 [ 8948.292241] lock_acquire+0xd7/0x310 [ 8948.292714] ? find_free_extent+0x141e/0x1590 [btrfs] [ 8948.293241] ? lock_is_held_type+0xea/0x140 [ 8948.293601] start_transaction+0x44c/0x6e0 [btrfs] [ 8948.294055] ? find_free_extent+0x141e/0x1590 [btrfs] [ 8948.294518] find_free_extent+0x141e/0x1590 [btrfs] [ 8948.294957] ? _raw_spin_unlock+0x29/0x40 [ 8948.295312] ? btrfs_get_alloc_profile+0x124/0x290 [btrfs] [ 8948.295813] btrfs_reserve_extent+0x14b/0x280 [btrfs] [ 8948.296270] cow_file_range+0x17e/0x490 [btrfs] [ 8948.296691] btrfs_run_delalloc_range+0x345/0x7a0 [btrfs] [ 8948.297175] ? find_lock_delalloc_range+0x247/0x270 [btrfs] [ 8948.297678] writepage_delalloc+0xb5/0x170 [btrfs] [ 8948.298123] __extent_writepage+0x156/0x3c0 [btrfs] [ 8948.298570] extent_write_cache_pages+0x263/0x460 [btrfs] [ 8948.299061] extent_writepages+0x76/0x130 [btrfs] [ 8948.299495] do_writepages+0xd2/0x1c0 [ 8948.299817] ? sched_clock_cpu+0xd/0x110 [ 8948.300160] ? lock_release+0x155/0x4a0 [ 8948.300494] filemap_fdatawrite_wbc+0x68/0x90 [ 8948.300874] ? do_raw_spin_unlock+0x4b/0xa0 [ 8948.301243] start_delalloc_inodes+0x17f/0x400 [btrfs] [ 8948.301706] ? lock_release+0x155/0x4a0 [ 8948.302055] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs] [ 8948.302564] flush_space+0x1f2/0x630 [btrfs] [ 8948.302970] btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs] [ 8948.303510] process_one_work+0x252/0x5a0 [ 8948.303860] ? process_one_work+0x5a0/0x5a0 [ 8948.304221] worker_thread+0x55/0x3b0 [ 8948.304543] ? process_one_work+0x5a0/0x5a0 [ 8948.304904] kthread+0xf2/0x120 [ 8948.305184] ? kthread_complete_and_exit+0x20/0x20 [ 8948.305598] ret_from_fork+0x22/0x30 [ 8948.305921] </TASK> It all comes from the fact that btrfs_start_delalloc_roots() takes the delalloc_root_mutex, in the transaction commit path we are holding a read lock on one of the superblock's freeze semaphores (via sb_start_intwrite()), the async reclaim task can also do a call to btrfs_start_delalloc_roots(), which ends up triggering writeback with calls to filemap_fdatawrite_wbc(), resulting in extent allocation which in turn can call btrfs_start_transaction(), which will result in taking the freeze semaphore via sb_start_intwrite(), forming a nasty dependency on all those locks which can be taken in different orders by different code paths. So just adopt the simple approach of calling try_to_writeback_inodes_sb() at btrfs_start_delalloc_flush(). Link: https://lore.kernel.org/linux-btrfs/20220130005258.GA7465@cuci.nl/ Link: https://lore.kernel.org/linux-btrfs/43acc426-d683-d1b6-729d-c6bc4a2fff4d@gm… Link: https://lore.kernel.org/linux-btrfs/6833930a-08d7-6fbc-0141-eb9cdfd6bb4d@gm… Link: https://lore.kernel.org/linux-btrfs/20190322041731.GF16651@hungrycats.org/ Reviewed-by: Omar Sandoval <osandov(a)fb.com> Signed-off-by: Filipe Manana <fdmanana(a)suse.com> [ add more link reports ] Signed-off-by: David Sterba <dsterba(a)suse.com> [Minor context change fixed] Signed-off-by: Zhi Yang <Zhi.Yang(a)windriver.com> Signed-off-by: He Zhe <zhe.he(a)windriver.com> --- Build test passed. --- fs/btrfs/transaction.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 21a5a963c70e..8c0703f8037b 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -2021,16 +2021,24 @@ static inline int btrfs_start_delalloc_flush(struct btrfs_trans_handle *trans) struct btrfs_fs_info *fs_info = trans->fs_info; /* - * We use writeback_inodes_sb here because if we used + * We use try_to_writeback_inodes_sb() here because if we used * btrfs_start_delalloc_roots we would deadlock with fs freeze. * Currently are holding the fs freeze lock, if we do an async flush * we'll do btrfs_join_transaction() and deadlock because we need to * wait for the fs freeze lock. Using the direct flushing we benefit * from already being in a transaction and our join_transaction doesn't * have to re-take the fs freeze lock. + * + * Note that try_to_writeback_inodes_sb() will only trigger writeback + * if it can read lock sb->s_umount. It will always be able to lock it, + * except when the filesystem is being unmounted or being frozen, but in + * those cases sync_filesystem() is called, which results in calling + * writeback_inodes_sb() while holding a write lock on sb->s_umount. + * Note that we don't call writeback_inodes_sb() directly, because it + * will emit a warning if sb->s_umount is not locked. */ if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) { - writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC); + try_to_writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC); } else { struct btrfs_pending_snapshot *pending; struct list_head *head = &trans->transaction->pending_snapshots; -- 2.34.1

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