February 2025 - Linux-stable-mirror

[PATCH v2] mm: zswap: fix crypto_free_acomp() deadlock in zswap_cpu_comp_dead()

by Yosry Ahmed

Currently, zswap_cpu_comp_dead() calls crypto_free_acomp() while holding the per-CPU acomp_ctx mutex. crypto_free_acomp() then holds scomp_lock (through crypto_exit_scomp_ops_async()). On the other hand, crypto_alloc_acomp_node() holds the scomp_lock (through crypto_scomp_init_tfm()), and then allocates memory. If the allocation results in reclaim, we may attempt to hold the per-CPU acomp_ctx mutex. The above dependencies can cause an ABBA deadlock. For example in the following scenario: (1) Task A running on CPU #1: crypto_alloc_acomp_node() Holds scomp_lock Enters reclaim Reads per_cpu_ptr(pool->acomp_ctx, 1) (2) Task A is descheduled (3) CPU #1 goes offline zswap_cpu_comp_dead(CPU #1) Holds per_cpu_ptr(pool->acomp_ctx, 1)) Calls crypto_free_acomp() Waits for scomp_lock (4) Task A running on CPU #2: Waits for per_cpu_ptr(pool->acomp_ctx, 1) // Read on CPU #1 DEADLOCK Since there is no requirement to call crypto_free_acomp() with the per-CPU acomp_ctx mutex held in zswap_cpu_comp_dead(), move it after the mutex is unlocked. Also move the acomp_request_free() and kfree() calls for consistency and to avoid any potential sublte locking dependencies in the future. With this, only setting acomp_ctx fields to NULL occurs with the mutex held. This is similar to how zswap_cpu_comp_prepare() only initializes acomp_ctx fields with the mutex held, after performing all allocations before holding the mutex. Opportunistically, move the NULL check on acomp_ctx so that it takes place before the mutex dereference. Fixes: 12dcb0ef5406 ("mm: zswap: properly synchronize freeing resources during CPU hotunplug") Reported-by: syzbot+1a517ccfcbc6a7ab0f82(a)syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/67bcea51.050a0220.bbfd1.0096.GAE@google.com/ Cc: <stable(a)vger.kernel.org> Co-developed-by: Herbert Xu <herbert(a)gondor.apana.org.au> Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au> Signed-off-by: Yosry Ahmed <yosry.ahmed(a)linux.dev> Acked-by: Herbert Xu <herbert(a)gondor.apana.org.au> --- v1 -> v2: - Explained the problem more clearly in the commit message. - Moved all freeing calls outside the lock critical section. v1: https://lore.kernel.org/all/Z72FJnbA39zWh4zS@gondor.apana.org.au/ --- mm/zswap.c | 30 ++++++++++++++++++++++-------- 1 file changed, 22 insertions(+), 8 deletions(-) diff --git a/mm/zswap.c b/mm/zswap.c index ac9d299e7d0c1..adf745c66aa1d 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -881,18 +881,32 @@ static int zswap_cpu_comp_dead(unsigned int cpu, struct hlist_node *node) { struct zswap_pool *pool = hlist_entry(node, struct zswap_pool, node); struct crypto_acomp_ctx *acomp_ctx = per_cpu_ptr(pool->acomp_ctx, cpu); + struct acomp_req *req; + struct crypto_acomp *acomp; + u8 *buffer; + + if (IS_ERR_OR_NULL(acomp_ctx)) + return 0; mutex_lock(&acomp_ctx->mutex); - if (!IS_ERR_OR_NULL(acomp_ctx)) { - if (!IS_ERR_OR_NULL(acomp_ctx->req)) - acomp_request_free(acomp_ctx->req); - acomp_ctx->req = NULL; - if (!IS_ERR_OR_NULL(acomp_ctx->acomp)) - crypto_free_acomp(acomp_ctx->acomp); - kfree(acomp_ctx->buffer); - } + req = acomp_ctx->req; + acomp = acomp_ctx->acomp; + buffer = acomp_ctx->buffer; + acomp_ctx->req = NULL; + acomp_ctx->acomp = NULL; + acomp_ctx->buffer = NULL; mutex_unlock(&acomp_ctx->mutex); + /* + * Do the actual freeing after releasing the mutex to avoid subtle + * locking dependencies causing deadlocks. + */ + if (!IS_ERR_OR_NULL(req)) + acomp_request_free(req); + if (!IS_ERR_OR_NULL(acomp)) + crypto_free_acomp(acomp); + kfree(buffer); + return 0; } -- 2.48.1.658.g4767266eb4-goog

3 weeks, 2 days

4
10
0 0

[PATCH 1/3] drm/i915: Fix scanline_offset for LNL+ and BMG+

by Ville Syrjala

From: Ville Syrjälä <ville.syrjala(a)linux.intel.com> Turns out LNL+ and BMG+ no longer have the weird extra scanline offset for HDMI outputs. Fix intel_crtc_scanline_offset() accordingly so that scanline evasion/etc. works correctly on HDMI outputs on these new platforms. Cc: stable(a)vger.kernel.org Signed-off-by: Ville Syrjälä <ville.syrjala(a)linux.intel.com> --- drivers/gpu/drm/i915/display/intel_vblank.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_vblank.c b/drivers/gpu/drm/i915/display/intel_vblank.c index 4efd4f7d497a..7b240ce681a0 100644 --- a/drivers/gpu/drm/i915/display/intel_vblank.c +++ b/drivers/gpu/drm/i915/display/intel_vblank.c @@ -222,7 +222,9 @@ int intel_crtc_scanline_offset(const struct intel_crtc_state *crtc_state) * However if queried just before the start of vblank we'll get an * answer that's slightly in the future. */ - if (DISPLAY_VER(display) == 2) + if (DISPLAY_VER(display) >= 20 || display->platform.battlemage) + return 1; + else if (DISPLAY_VER(display) == 2) return -1; else if (HAS_DDI(display) && intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI)) return 2; -- 2.45.3

3 weeks, 6 days

3
2
0 0

[PATCH v2] Revert "mmc: sdhci_am654: Add sdhci_am654_start_signal_voltage_switch"

by Josua Mayer

This reverts commit 941a7abd4666912b84ab209396fdb54b0dae685d. This commit uses presence of device-tree properties vmmc-supply and vqmmc-supply for deciding whether to enable a quirk affecting timing of clock and data. The intention was to address issues observed with eMMC and SD on AM62 platforms. This new quirk is however also enabled for AM64 breaking microSD access on the SolidRun HimmingBoard-T which is supported in-tree since v6.11, causing a regression. During boot microSD initialization now fails with the error below: [ 2.008520] mmc1: SDHCI controller on fa00000.mmc [fa00000.mmc] using ADMA 64-bit [ 2.115348] mmc1: error -110 whilst initialising SD card The heuristics for enabling the quirk are clearly not correct as they break at least one but potentially many existing boards. Revert the change and restore original behaviour until a more appropriate method of selecting the quirk is derived. Fixes: 941a7abd4666 ("mmc: sdhci_am654: Add sdhci_am654_start_signal_voltage_switch") Closes: https://lore.kernel.org/linux-mmc/a70fc9fc-186f-4165-a652-3de50733763a@soli… Cc: stable(a)vger.kernel.org Signed-off-by: Josua Mayer <josua(a)solid-run.com> Acked-by: Adrian Hunter <adrian.hunter(a)intel.com> --- Changes in v2: - Fixed "Fixes:" tag invalid commit description copied from history (Reported-by: Adrian Hunter <adrian.hunter(a)intel.com>) (Reported-by: Greg KH <gregkh(a)linuxfoundation.org>) - Link to v1: https://lore.kernel.org/r/20250127-am654-mmc-regression-v1-1-d831f9a13ae9@s… --- drivers/mmc/host/sdhci_am654.c | 30 ------------------------------ 1 file changed, 30 deletions(-) diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c index b73f673db92bbc042392995e715815e15ace6005..f75c31815ab00d17b5757063521f56ba5643babe 100644 --- a/drivers/mmc/host/sdhci_am654.c +++ b/drivers/mmc/host/sdhci_am654.c @@ -155,7 +155,6 @@ struct sdhci_am654_data { u32 tuning_loop; #define SDHCI_AM654_QUIRK_FORCE_CDTEST BIT(0) -#define SDHCI_AM654_QUIRK_SUPPRESS_V1P8_ENA BIT(1) }; struct window { @@ -357,29 +356,6 @@ static void sdhci_j721e_4bit_set_clock(struct sdhci_host *host, sdhci_set_clock(host, clock); } -static int sdhci_am654_start_signal_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios) -{ - struct sdhci_host *host = mmc_priv(mmc); - struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); - struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host); - int ret; - - if ((sdhci_am654->quirks & SDHCI_AM654_QUIRK_SUPPRESS_V1P8_ENA) && - ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180) { - if (!IS_ERR(mmc->supply.vqmmc)) { - ret = mmc_regulator_set_vqmmc(mmc, ios); - if (ret < 0) { - pr_err("%s: Switching to 1.8V signalling voltage failed,\n", - mmc_hostname(mmc)); - return -EIO; - } - } - return 0; - } - - return sdhci_start_signal_voltage_switch(mmc, ios); -} - static u8 sdhci_am654_write_power_on(struct sdhci_host *host, u8 val, int reg) { writeb(val, host->ioaddr + reg); @@ -868,11 +844,6 @@ static int sdhci_am654_get_of_property(struct platform_device *pdev, if (device_property_read_bool(dev, "ti,fails-without-test-cd")) sdhci_am654->quirks |= SDHCI_AM654_QUIRK_FORCE_CDTEST; - /* Suppress v1p8 ena for eMMC and SD with vqmmc supply */ - if (!!of_parse_phandle(dev->of_node, "vmmc-supply", 0) == - !!of_parse_phandle(dev->of_node, "vqmmc-supply", 0)) - sdhci_am654->quirks |= SDHCI_AM654_QUIRK_SUPPRESS_V1P8_ENA; - sdhci_get_of_property(pdev); return 0; @@ -969,7 +940,6 @@ static int sdhci_am654_probe(struct platform_device *pdev) goto err_pltfm_free; } - host->mmc_host_ops.start_signal_voltage_switch = sdhci_am654_start_signal_voltage_switch; host->mmc_host_ops.execute_tuning = sdhci_am654_execute_tuning; pm_runtime_get_noresume(dev); --- base-commit: ffd294d346d185b70e28b1a28abe367bbfe53c04 change-id: 20250127-am654-mmc-regression-ed289f8967c2 Best regards, -- Josua Mayer <josua(a)solid-run.com>

4 weeks

4
7
0 0

[PATCH RESEND] fs/netfs/read_collect: add to next->prev_donated

by Max Kellermann

If multiple subrequests donate data to the same "next" request (depending on the subrequest completion order), each of them would overwrite the `prev_donated` field, causing data corruption and a BUG() crash ("Can't donate prior to front"). Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading") Closes: https://lore.kernel.org/netfs/CAKPOu+_4mUwYgQtRTbXCmi+-k3PGvLysnPadkmHOyB7G… Cc: stable(a)vger.kernel.org Signed-off-by: Max Kellermann <max.kellermann(a)ionos.com> Signed-off-by: David Howells <dhowells(a)redhat.com> --- fs/netfs/read_collect.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/netfs/read_collect.c b/fs/netfs/read_collect.c index 8878b46589ff..cafadfe8e858 100644 --- a/fs/netfs/read_collect.c +++ b/fs/netfs/read_collect.c @@ -284,7 +284,7 @@ static bool netfs_consume_read_data(struct netfs_io_subrequest *subreq, bool was netfs_trace_donate_to_deferred_next); } else { next = list_next_entry(subreq, rreq_link); - WRITE_ONCE(next->prev_donated, excess); + WRITE_ONCE(next->prev_donated, next->prev_donated + excess); trace_netfs_donate(rreq, subreq, next, excess, netfs_trace_donate_to_next); } -- 2.47.2

4 weeks

4
3
0 0

[BUG REPORT] cifs: Deadlock due to network reconnection during file writing

by Wang Zhaolong

In the code of the LTS branch that is being maintained (from linux-5.4 to linux-6.6), a deadlock occurs in the network reconnection scenario When multiple processes or threads write to the same file concurrently. Take the code of linux-5.10 as an example. The simplified deadlock process is as follows: ``` Process 1 Process 2 lock_page() - [1] wait_on_page_writeback() - [2] Waiting for writeback, blocked by [4] lock_page() - [3] Blocked by [1] end_page_writeback() - [4] Won't execute ``` Based on my research, I'm going to use two detailed scenarios to illustrate the issue. Scenarios 1: ``` P1 (dd) P2 (cifsd) P3 (cifsiod) cifs_writepages wdata_prepare_pages lock_page - [1] wait_on_page_writeback - [2] Waiting for writeback, blocked by [4] wait_on_page_bit cifs_demultiplex_thread cifs_read_from_socket cifs_readv_from_socket - If another process triggers reconnect at this point cifs_reconnect - mid->mid_state updated to MID_RETRY_NEEDED smb2_writev_callback mid_entry->callback() - mid_state leads to wdata->result = -EAGAIN wdata->result = -EAGAIN queue_work(cifsiod_wq, &wdata->work); cifs_writev_complete - worker function - wdata->result == -EAGAIN Condition satisfied cifs_writev_requeue lock_page - [3] Blocked by [1] end_page_writeback - [4] Won't execute unlock_page ``` Mainline refactoring commit d08089f649a0 ("cifs: Change the I/O paths to use an iterator rather than a page list") unlock folio while waiting for the writeback to complete. This patch is introduced in v6.3-rc1. Therefore, scenario 1 only affects LTS versions from linux-5.4 to linux-6.1. Call stack trace: ``` cat /proc/34/stack [<0>] __lock_page+0x147/0x3a0 [<0>] cifs_writev_requeue.cold+0x185/0x28e [<0>] process_one_work+0x1df/0x3b0 [<0>] worker_thread+0x4a/0x3c0 [<0>] kthread+0x125/0x160 [<0>] ret_from_fork+0x22/0x30 # cat /proc/465/stack [<0>] wait_on_page_bit+0x106/0x2e0 [<0>] wait_on_page_writeback+0x25/0xd0 [<0>] cifs_writepages+0x5ee/0xf60 [<0>] do_writepages+0x43/0xe0 [<0>] __filemap_fdatawrite_range+0xcd/0x110 [<0>] file_write_and_wait_range+0x40/0x90 [<0>] cifs_strict_fsync+0x35/0x470 [<0>] do_fsync+0x38/0x70 [<0>] __x64_sys_fsync+0x10/0x20 [<0>] do_syscall_64+0x33/0x40 [<0>] entry_SYSCALL_64_after_hwframe+0x67/0xd1 [ 369.826215] INFO: task kworker/1:1:34 blocked for more than 122 seconds. [ 369.828964] Not tainted 5.10.0+ #164 [ 369.830623] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 369.835104] task:kworker/1:1 state:D stack:13472 pid: 34 ppid: 2 flags:0x00004000 [ 369.838448] Workqueue: cifsiod cifs_writev_complete [ 369.840242] Call Trace: [ 369.841219] __schedule+0x401/0x8e0 [ 369.842568] schedule+0x49/0x130 [ 369.843785] io_schedule+0x12/0x40 [ 369.845079] __lock_page+0x147/0x3a0 [ 369.846444] ? add_to_page_cache_lru+0x180/0x180 [ 369.847963] cifs_writev_requeue.cold+0x185/0x28e [ 369.849193] process_one_work+0x1df/0x3b0 [ 369.850248] worker_thread+0x4a/0x3c0 [ 369.851216] ? process_one_work+0x3b0/0x3b0 [ 369.852308] kthread+0x125/0x160 [ 369.853167] ? kthread_park+0x90/0x90 [ 369.854142] ret_from_fork+0x22/0x30 [ 369.855054] INFO: task kworker/u8:3:96 blocked for more than 122 seconds. [ 369.856781] Not tainted 5.10.0+ #164 [ 369.857851] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 369.859419] task:kworker/u8:3 state:D stack:12744 pid: 96 ppid: 2 flags:0x00004000 [ 369.861041] Workqueue: writeback wb_workfn (flush-cifs-2) [ 369.862095] Call Trace: [ 369.862583] __schedule+0x401/0x8e0 [ 369.863280] schedule+0x49/0x130 [ 369.863912] io_schedule+0x12/0x40 [ 369.864604] __lock_page+0x147/0x3a0 [ 369.865322] ? add_to_page_cache_lru+0x180/0x180 [ 369.866246] cifs_writepages+0x620/0xf60 [ 369.867005] do_writepages+0x43/0xe0 [ 369.867737] ? __blk_mq_try_issue_directly+0x121/0x1c0 [ 369.868750] __writeback_single_inode+0x3d/0x320 [ 369.869589] writeback_sb_inodes+0x20d/0x480 [ 369.870367] __writeback_inodes_wb+0x4c/0xe0 [ 369.871148] wb_writeback+0x201/0x2f0 [ 369.871797] wb_workfn+0x38a/0x4e0 [ 369.872427] ? check_preempt_curr+0x47/0x70 [ 369.873191] ? ttwu_do_wakeup.isra.0+0x17/0x170 [ 369.873999] process_one_work+0x1df/0x3b0 [ 369.874741] worker_thread+0x4a/0x3c0 [ 369.875421] ? process_one_work+0x3b0/0x3b0 [ 369.876180] kthread+0x125/0x160 [ 369.876761] ? kthread_park+0x90/0x90 [ 369.877431] ret_from_fork+0x22/0x30 [ 369.878106] INFO: task a.out:465 blocked for more than 122 seconds. [ 369.879225] Not tainted 5.10.0+ #164 [ 369.879945] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 369.881316] task:a.out state:D stack:12752 pid: 465 ppid: 386 flags:0x00000002 [ 369.882791] Call Trace: [ 369.883263] __schedule+0x401/0x8e0 [ 369.883884] schedule+0x49/0x130 [ 369.884447] io_schedule+0x12/0x40 [ 369.885054] wait_on_page_bit+0x106/0x2e0 [ 369.885795] ? add_to_page_cache_lru+0x180/0x180 [ 369.886631] wait_on_page_writeback+0x25/0xd0 [ 369.887427] cifs_writepages+0x5ee/0xf60 [ 369.888151] do_writepages+0x43/0xe0 [ 369.888789] ? __generic_file_write_iter+0xfd/0x1d0 [ 369.889663] __filemap_fdatawrite_range+0xcd/0x110 [ 369.890523] file_write_and_wait_range+0x40/0x90 [ 369.891360] cifs_strict_fsync+0x35/0x470 [ 369.892094] do_fsync+0x38/0x70 [ 369.892657] __x64_sys_fsync+0x10/0x20 [ 369.893336] do_syscall_64+0x33/0x40 [ 369.893978] entry_SYSCALL_64_after_hwframe+0x67/0xd1 [ 369.894883] RIP: 0033:0x7f660e208950 [ 369.895538] RSP: 002b:00007fff52b27b78 EFLAGS: 00000202 ORIG_RAX: 000000000000004a [ 369.896882] RAX: ffffffffffffffda RBX: 00007fff52b28cb8 RCX: 00007f660e208950 [ 369.898139] RDX: 0000000000001000 RSI: 00007fff52b27b80 RDI: 0000000000000003 [ 369.899395] RBP: 00007fff52b28ba0 R08: 0000000000000410 R09: 0000000000000001 [ 369.900661] R10: 00007f660e11c400 R11: 0000000000000202 R12: 0000000000000000 [ 369.901925] R13: 00007fff52b28cc8 R14: 00007f660e328000 R15: 000055b5aeb6fdd8 [ 369.903202] INFO: task sync:468 blocked for more than 122 seconds. [ 369.904311] Not tainted 5.10.0+ #164 [ 369.905034] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 369.906457] task:sync state:D stack:13632 pid: 468 ppid: 386 flags:0x00004002 [ 369.907930] Call Trace: [ 369.908369] __schedule+0x401/0x8e0 [ 369.908984] schedule+0x49/0x130 [ 369.909582] io_schedule+0x12/0x40 [ 369.910208] wait_on_page_bit+0x106/0x2e0 [ 369.910918] ? add_to_page_cache_lru+0x180/0x180 [ 369.911758] wait_on_page_writeback+0x25/0xd0 [ 369.912560] __filemap_fdatawait_range+0x83/0x110 [ 369.913408] ? __add_pages+0x6f/0x1b0 [ 369.914089] filemap_fdatawait_keep_errors+0x1a/0x50 [ 369.914957] sync_inodes_sb+0x208/0x2a0 [ 369.915666] ? __x64_sys_tee+0xd0/0xd0 [ 369.916344] iterate_supers+0x90/0xe0 [ 369.916983] ksys_sync+0x40/0xb0 [ 369.917590] __do_sys_sync+0xa/0x20 [ 369.918240] do_syscall_64+0x33/0x40 [ 369.918884] entry_SYSCALL_64_after_hwframe+0x67/0xd1 [ 369.919800] RIP: 0033:0x7f746d820987 [ 369.920451] RSP: 002b:00007ffce853fd78 EFLAGS: 00000206 ORIG_RAX: 00000000000000a2 [ 369.921798] RAX: ffffffffffffffda RBX: 00007ffce853fed8 RCX: 00007f746d820987 [ 369.923063] RDX: 00007f746d8f4801 RSI: 00007ffce8541f71 RDI: 00007f746d8b05ad [ 369.924339] RBP: 0000000000000001 R08: 000000000000ffff R09: 0000000000000000 [ 369.925605] R10: 00007f746d7308a0 R11: 0000000000000206 R12: 000055b8487470fb [ 369.926866] R13: 0000000000000000 R14: 0000000000000000 R15: 000055b848749ce0 [ 369.928138] Kernel panic - not syncing: hung_task: blocked tasks [ 369.929191] CPU: 3 PID: 35 Comm: khungtaskd Not tainted 5.10.0+ #164 [ 369.952450] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 [ 369.956984] Call Trace: [ 369.957973] dump_stack+0x57/0x6e [ 369.959273] panic+0x115/0x2f1 [ 369.960476] watchdog.cold+0xb5/0xb5 [ 369.961884] ? hungtask_pm_notify+0x40/0x40 [ 369.963310] kthread+0x125/0x160 [ 369.964354] ? kthread_park+0x90/0x90 [ 369.965551] ret_from_fork+0x22/0x30 [ 369.967673] Kernel Offset: 0xd600000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 369.971025] ---[ end Kernel panic - not syncing: hung_task: blocked tasks ]--- ``` Scenarios 2: Scenario 2 occurs in strict cache mode ``` P1 (dd) P2 (cifsd) P3 (cifsiod) cifs_strict_writev cifs_zap_mapping - If something breaks the oplock cifs_revalidate_mapping cifs_invalidate_mapping invalidate_inode_pages2 invalidate_inode_pages2_range lock_page - [1] wait_on_page_writeback - [2] Waiting for writeback, blocked by [4] wait_on_page_bit cifs_demultiplex_thread cifs_read_from_socket cifs_readv_from_socket - If another process triggers reconnect at this point cifs_reconnect - mid->mid_state updated to MID_RETRY_NEEDED smb2_writev_callback mid_entry->callback() - mid_state leads to wdata->result = -EAGAIN wdata->result = -EAGAIN queue_work(cifsiod_wq, &wdata->work); cifs_writev_complete - worker function - wdata->result == -EAGAIN Condition satisfied cifs_writev_requeue lock_page - [3] Blocked by [1] end_page_writeback - [4] Won't execute unlock_page ``` Mainline refactoring commit 3ee1a1fc3981 ("cifs: Cut over to using netfslib") directly terminates the file write instead of resending data when smb2_writev_callback() detects a write failure, thus avoiding this problem. This patch is introduced in v6.10-rc1. Therefore, scenario 2 affects LTS versions from linux-5.4 to linux-6.6. ``` cat /proc/522/stack [<0>] wait_on_page_bit+0x106/0x150 [<0>] invalidate_inode_pages2_range+0x2cc/0x580 [<0>] cifs_invalidate_mapping+0x2c/0x50 [cifs] [<0>] cifs_revalidate_mapping+0x4c/0x90 [cifs] [<0>] cifs_strict_writev+0x17a/0x250 [cifs] [<0>] __vfs_write+0x14f/0x1b0 [<0>] vfs_write+0xb6/0x1a0 [<0>] ksys_write+0x57/0xd0 [<0>] do_syscall_64+0x63/0x250 [<0>] entry_SYSCALL_64_after_hwframe+0x5c/0xc1 [<0>] 0xffffffffffffffff cat /proc/33/stack [<0>] __lock_page+0x10c/0x160 [<0>] cifs_writev_requeue.cold+0x17e/0x239 [cifs] [<0>] process_one_work+0x1a9/0x3f0 [<0>] worker_thread+0x50/0x3c0 [<0>] kthread+0x117/0x130 [<0>] ret_from_fork+0x35/0x40 [<0>] 0xffffffffffffffff ``` The root cause of the deadlock problem is that the page/folio is locked again in cifs_writev_requeue(). In order to safely fix it on the LTS branches, I would like to clarify the following questions:, 1. Whether resending is necessary. If retransmission is not required, simply terminating the write would avoids this problem. Is this an acceptable solution? 2. Is it necessary to lock the page/folio in cifs_writev_requeue()? Based on my code screening (possibly missing), there seems to be no process that modifies a page when it is marked as PG_writeback.Therefore, the page does not need to be locked during wait_on_page_writeback().

4 weeks, 1 day

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FAILED: patch "[PATCH] block: fix missing dispatching request when queue is started" 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 2003ee8a9aa14d766b06088156978d53c2e9be3d # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024120323-snowiness-subway-3844@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 2003ee8a9aa14d766b06088156978d53c2e9be3d Mon Sep 17 00:00:00 2001 From: Muchun Song <muchun.song(a)linux.dev> Date: Mon, 14 Oct 2024 17:29:32 +0800 Subject: [PATCH] block: fix missing dispatching request when queue is started or unquiesced Supposing the following scenario with a virtio_blk driver. CPU0 CPU1 CPU2 blk_mq_try_issue_directly() __blk_mq_issue_directly() q->mq_ops->queue_rq() virtio_queue_rq() blk_mq_stop_hw_queue() virtblk_done() blk_mq_try_issue_directly() if (blk_mq_hctx_stopped()) blk_mq_request_bypass_insert() blk_mq_run_hw_queue() blk_mq_run_hw_queue() blk_mq_run_hw_queue() blk_mq_insert_request() return After CPU0 has marked the queue as stopped, CPU1 will see the queue is stopped. But before CPU1 puts the request on the dispatch list, CPU2 receives the interrupt of completion of request, so it will run the hardware queue and marks the queue as non-stopped. Meanwhile, CPU1 also runs the same hardware queue. After both CPU1 and CPU2 complete blk_mq_run_hw_queue(), CPU1 just puts the request to the same hardware queue and returns. It misses dispatching a request. Fix it by running the hardware queue explicitly. And blk_mq_request_issue_directly() should handle a similar situation. Fix it as well. Fixes: d964f04a8fde ("blk-mq: fix direct issue") Cc: stable(a)vger.kernel.org Cc: Muchun Song <muchun.song(a)linux.dev> Signed-off-by: Muchun Song <songmuchun(a)bytedance.com> Reviewed-by: Ming Lei <ming.lei(a)redhat.com> Link: https://lore.kernel.org/r/20241014092934.53630-2-songmuchun@bytedance.com Signed-off-by: Jens Axboe <axboe(a)kernel.dk> diff --git a/block/blk-mq.c b/block/blk-mq.c index 7d05a56e3639..5deb9dffca0a 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2647,6 +2647,7 @@ static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(rq->q)) { blk_mq_insert_request(rq, 0); + blk_mq_run_hw_queue(hctx, false); return; } @@ -2677,6 +2678,7 @@ static blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last) if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(rq->q)) { blk_mq_insert_request(rq, 0); + blk_mq_run_hw_queue(hctx, false); return BLK_STS_OK; }

1 month

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FAILED: patch "[PATCH] block: fix ordering between checking QUEUE_FLAG_QUIESCED" 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 6bda857bcbb86fb9d0e54fbef93a093d51172acc # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024120342-monsoon-wildcat-d0a1@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 6bda857bcbb86fb9d0e54fbef93a093d51172acc Mon Sep 17 00:00:00 2001 From: Muchun Song <muchun.song(a)linux.dev> Date: Mon, 14 Oct 2024 17:29:33 +0800 Subject: [PATCH] block: fix ordering between checking QUEUE_FLAG_QUIESCED request adding Supposing the following scenario. CPU0 CPU1 blk_mq_insert_request() 1) store blk_mq_unquiesce_queue() blk_queue_flag_clear() 3) store blk_mq_run_hw_queues() blk_mq_run_hw_queue() if (!blk_mq_hctx_has_pending()) 4) load return blk_mq_run_hw_queue() if (blk_queue_quiesced()) 2) load return blk_mq_sched_dispatch_requests() The full memory barrier should be inserted between 1) and 2), as well as between 3) and 4) to make sure that either CPU0 sees QUEUE_FLAG_QUIESCED is cleared or CPU1 sees dispatch list or setting of bitmap of software queue. Otherwise, either CPU will not rerun the hardware queue causing starvation. So the first solution is to 1) add a pair of memory barrier to fix the problem, another solution is to 2) use hctx->queue->queue_lock to synchronize QUEUE_FLAG_QUIESCED. Here, we chose 2) to fix it since memory barrier is not easy to be maintained. Fixes: f4560ffe8cec ("blk-mq: use QUEUE_FLAG_QUIESCED to quiesce queue") Cc: stable(a)vger.kernel.org Cc: Muchun Song <muchun.song(a)linux.dev> Signed-off-by: Muchun Song <songmuchun(a)bytedance.com> Reviewed-by: Ming Lei <ming.lei(a)redhat.com> Link: https://lore.kernel.org/r/20241014092934.53630-3-songmuchun@bytedance.com Signed-off-by: Jens Axboe <axboe(a)kernel.dk> diff --git a/block/blk-mq.c b/block/blk-mq.c index 5deb9dffca0a..bb4ee2380dce 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2227,6 +2227,24 @@ void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) } EXPORT_SYMBOL(blk_mq_delay_run_hw_queue); +static inline bool blk_mq_hw_queue_need_run(struct blk_mq_hw_ctx *hctx) +{ + bool need_run; + + /* + * When queue is quiesced, we may be switching io scheduler, or + * updating nr_hw_queues, or other things, and we can't run queue + * any more, even blk_mq_hctx_has_pending() can't be called safely. + * + * And queue will be rerun in blk_mq_unquiesce_queue() if it is + * quiesced. + */ + __blk_mq_run_dispatch_ops(hctx->queue, false, + need_run = !blk_queue_quiesced(hctx->queue) && + blk_mq_hctx_has_pending(hctx)); + return need_run; +} + /** * blk_mq_run_hw_queue - Start to run a hardware queue. * @hctx: Pointer to the hardware queue to run. @@ -2247,20 +2265,23 @@ void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) might_sleep_if(!async && hctx->flags & BLK_MQ_F_BLOCKING); - /* - * When queue is quiesced, we may be switching io scheduler, or - * updating nr_hw_queues, or other things, and we can't run queue - * any more, even __blk_mq_hctx_has_pending() can't be called safely. - * - * And queue will be rerun in blk_mq_unquiesce_queue() if it is - * quiesced. - */ - __blk_mq_run_dispatch_ops(hctx->queue, false, - need_run = !blk_queue_quiesced(hctx->queue) && - blk_mq_hctx_has_pending(hctx)); + need_run = blk_mq_hw_queue_need_run(hctx); + if (!need_run) { + unsigned long flags; - if (!need_run) - return; + /* + * Synchronize with blk_mq_unquiesce_queue(), because we check + * if hw queue is quiesced locklessly above, we need the use + * ->queue_lock to make sure we see the up-to-date status to + * not miss rerunning the hw queue. + */ + spin_lock_irqsave(&hctx->queue->queue_lock, flags); + need_run = blk_mq_hw_queue_need_run(hctx); + spin_unlock_irqrestore(&hctx->queue->queue_lock, flags); + + if (!need_run) + return; + } if (async || !cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask)) { blk_mq_delay_run_hw_queue(hctx, 0);

1 month

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[PATCH] ASoC: codecs: wcd937x: fix a potential memory leak in wcd937x_soc_codec_probe()

by Haoxiang Li

When snd_soc_dapm_new_controls() or snd_soc_dapm_add_routes() fails, wcd937x_soc_codec_probe() returns without releasing 'wcd937x->clsh_info', which is allocated by wcd_clsh_ctrl_alloc. Add wcd_clsh_ctrl_free() to prevent potential memory leak. Fixes: 313e978df7fc ("ASoC: codecs: wcd937x: add audio routing and Kconfig") Cc: stable(a)vger.kernel.org Signed-off-by: Haoxiang Li <haoxiang_li2024(a)163.com> --- sound/soc/codecs/wcd937x.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/sound/soc/codecs/wcd937x.c b/sound/soc/codecs/wcd937x.c index c9d5e67bf66e..951fd1caf847 100644 --- a/sound/soc/codecs/wcd937x.c +++ b/sound/soc/codecs/wcd937x.c @@ -2563,6 +2563,7 @@ static int wcd937x_soc_codec_probe(struct snd_soc_component *component) ARRAY_SIZE(wcd9375_dapm_widgets)); if (ret < 0) { dev_err(component->dev, "Failed to add snd_ctls\n"); + wcd_clsh_ctrl_free(wcd937x->clsh_info); return ret; } @@ -2570,6 +2571,7 @@ static int wcd937x_soc_codec_probe(struct snd_soc_component *component) ARRAY_SIZE(wcd9375_audio_map)); if (ret < 0) { dev_err(component->dev, "Failed to add routes\n"); + wcd_clsh_ctrl_free(wcd937x->clsh_info); return ret; } } -- 2.25.1

1 month

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[REGRESSION][BISECTED] Commit 60e3318e3e900 in stable/linux-6.1.y breaks cifs client failover to another server in DFS namespace

by Andrew Paniakin

Commit 60e3318e3e900 ("cifs: use fs_context for automounts") was released in v6.1.54 and broke the failover when one of the servers inside DFS becomes unavailable. We reproduced the problem on the EC2 instances of different types. Reverting aforementioned commint on top of the latest stable verison v6.1.94 helps to resolve the problem. Earliest working version is v6.2-rc1. There were two big merges of CIFS fixes: [1] and [2]. We would like to ask for the help to investigate this problem and if some of those patches need to be backported. Also, is it safe to just revert problematic commit until proper fixes/backports will be available? We will help to do testing and confirm if fix works, but let me also list the steps we used to reproduce the problem if it will help to identify the problem: 1. Create Active Directory domain eg. 'corp.fsxtest.local' in AWS Directory Service with: - three AWS FSX file systems filesystem1..filesystem3 - three Windows servers; They have DFS installed as per https://learn.microsoft.com/en-us/windows-server/storage/dfs-namespaces/dfs…: - dfs-srv1: EC2AMAZ-2EGTM59 - dfs-srv2: EC2AMAZ-1N36PRD - dfs-srv3: EC2AMAZ-0PAUH2U 2. Create DFS namespace eg. 'dfs-namespace' in Windows server 2008 mode and three folders targets in it: - referral-a mapped to filesystem1.corp.local - referral-b mapped to filesystem2.corp.local - referral-c mapped to filesystem3.corp.local - local folders dfs-srv1..dfs-srv3 in C:\DFSRoots\dfs-namespace of every Windows server. This helps to quickly define underlying server when DFS is mounted. 3. Enabled cifs debug logs: ``` echo 'module cifs +p' > /sys/kernel/debug/dynamic_debug/control echo 'file fs/cifs/* +p' > /sys/kernel/debug/dynamic_debug/control echo 7 > /proc/fs/cifs/cifsFYI ``` 4. Mount DFS namespace on Amazon Linux 2023 instance running any vanilla kernel v6.1.54+: ``` dmesg -c &>/dev/null cd /mnt mount -t cifs -o cred=/mnt/creds,echo_interval=5 \ //corp.fsxtest.local/dfs-namespace \ ./dfs-namespace ``` 5. List DFS root, it's also required to avoid recursive mounts that happen during regular 'ls' run: ``` sh -c 'ls dfs-namespace' dfs-srv2 referral-a referral-b ``` The DFS server is EC2AMAZ-1N36PRD, it's also listed in mount: ``` [root@ip-172-31-2-82 mnt]# mount | grep dfs //corp.fsxtest.local/dfs-namespace on /mnt/dfs-namespace type cifs (rw,relatime,vers=3.1.1,cache=strict,username=Admin,domain=corp.fsxtest.local,uid=0,noforceuid,gid=0,noforcegid,addr=172.31.11.26,file_mode=0755,dir_mode=0755,soft,nounix,mapposix,rsize=4194304,wsize=4194304,bsize=1048576,echo_interval=5,actimeo=1,closetimeo=1) //EC2AMAZ-1N36PRD.corp.fsxtest.local/dfs-namespace/referral-a on /mnt/dfs-namespace/referral-a type cifs (rw,relatime,vers=3.1.1,cache=strict,username=Admin,domain=corp.fsxtest.local,uid=0,noforceuid,gid=0,noforcegid,addr=172.31.12.80,file_mode=0755,dir_mode=0755,soft,nounix,mapposix,rsize=4194304,wsize=4194304,bsize=1048576,echo_interval=5,actimeo=1,closetimeo=1) ``` List files in first folder: ``` sh -c 'ls dfs-namespace/referral-a' filea.txt.txt ``` 6. Shutdown DFS server-2. List DFS root again, server changed from dfs-srv2 to dfs-srv1 EC2AMAZ-2EGTM59: ``` sh -c 'ls dfs-namespace' dfs-srv1 referral-a referral-b ``` 7. Try to list files in another folder, this causes ls to fail with error: ``` sh -c 'ls dfs-namespace/referral-b' ls: cannot access 'dfs-namespace/referral-b': No route to host``` Sometimes it's also 'Operation now in progress' error. mount shows the same output: ``` //corp.fsxtest.local/dfs-namespace on /mnt/dfs-namespace type cifs (rw,relatime,vers=3.1.1,cache=strict,username=Admin,domain=corp.fsxtest.local,uid=0,noforceuid,gid=0,noforcegid,addr=172.31.11.26,file_mode=0755,dir_mode=0755,soft,nounix,mapposix,rsize=4194304,wsize=4194304,bsize=1048576,echo_interval=5,actimeo=1,closetimeo=1) //EC2AMAZ-1N36PRD.corp.fsxtest.local/dfs-namespace/referral-a on /mnt/dfs-namespace/referral-a type cifs (rw,relatime,vers=3.1.1,cache=strict,username=Admin,domain=corp.fsxtest.local,uid=0,noforceuid,gid=0,noforcegid,addr=172.31.12.80,file_mode=0755,dir_mode=0755,soft,nounix,mapposix,rsize=4194304,wsize=4194304,bsize=1048576,echo_interval=5,actimeo=1,closetimeo=1) ``` I also attached kernel debug logs from this test. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… Reported-by: Andrei Paniakin <apanyaki(a)amazon.com> Bisected-by: Simba Bonga <simbarb(a)amazon.com> --- #regzbot introduced: v6.1.54..v6.2-rc1

1 month

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[PATCH AUTOSEL 6.13 01/32] selftests/bpf: Adjust data size to have ETH_HLEN

by Sasha Levin

From: Shigeru Yoshida <syoshida(a)redhat.com> [ Upstream commit c7f2188d68c114095660a950b7e880a1e5a71c8f ] The function bpf_test_init() now returns an error if user_size (.data_size_in) is less than ETH_HLEN, causing the tests to fail. Adjust the data size to ensure it meets the requirement of ETH_HLEN. Signed-off-by: Shigeru Yoshida <syoshida(a)redhat.com> Signed-off-by: Martin KaFai Lau <martin.lau(a)kernel.org> Link: https://patch.msgid.link/20250121150643.671650-2-syoshida@redhat.com Signed-off-by: Alexei Starovoitov <ast(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- .../testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c | 4 ++-- .../testing/selftests/bpf/prog_tests/xdp_devmap_attach.c | 8 ++++---- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c b/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c index c7f74f068e788..df27535995af8 100644 --- a/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c +++ b/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c @@ -52,10 +52,10 @@ static void test_xdp_with_cpumap_helpers(void) ASSERT_EQ(info.id, val.bpf_prog.id, "Match program id to cpumap entry prog_id"); /* send a packet to trigger any potential bugs in there */ - char data[10] = {}; + char data[ETH_HLEN] = {}; DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts, .data_in = &data, - .data_size_in = 10, + .data_size_in = sizeof(data), .flags = BPF_F_TEST_XDP_LIVE_FRAMES, .repeat = 1, ); diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c b/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c index 27ffed17d4be3..461ab18705d5c 100644 --- a/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c +++ b/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c @@ -23,7 +23,7 @@ static void test_xdp_with_devmap_helpers(void) __u32 len = sizeof(info); int err, dm_fd, dm_fd_redir, map_fd; struct nstoken *nstoken = NULL; - char data[10] = {}; + char data[ETH_HLEN] = {}; __u32 idx = 0; SYS(out_close, "ip netns add %s", TEST_NS); @@ -58,7 +58,7 @@ static void test_xdp_with_devmap_helpers(void) /* send a packet to trigger any potential bugs in there */ DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts, .data_in = &data, - .data_size_in = 10, + .data_size_in = sizeof(data), .flags = BPF_F_TEST_XDP_LIVE_FRAMES, .repeat = 1, ); @@ -158,7 +158,7 @@ static void test_xdp_with_devmap_helpers_veth(void) struct nstoken *nstoken = NULL; __u32 len = sizeof(info); int err, dm_fd, dm_fd_redir, map_fd, ifindex_dst; - char data[10] = {}; + char data[ETH_HLEN] = {}; __u32 idx = 0; SYS(out_close, "ip netns add %s", TEST_NS); @@ -208,7 +208,7 @@ static void test_xdp_with_devmap_helpers_veth(void) /* send a packet to trigger any potential bugs in there */ DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts, .data_in = &data, - .data_size_in = 10, + .data_size_in = sizeof(data), .flags = BPF_F_TEST_XDP_LIVE_FRAMES, .repeat = 1, ); -- 2.39.5

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Linux-stable-mirror February 2025