December 2024 - Linux-stable-mirror

[PATCH] Revert "MIPS: csrc-r4k: Select HAVE_UNSTABLE_SCHED_CLOCK if SMP && 64BIT"

by Xi Ruoyao

This reverts commit 426fa8e4fe7bb914b5977cbce453a9926bf5b2e6. The commit has caused two issues on Loongson 3A4000: 1. The timestamp in dmesg become erratic, like: [3.736957] amdgpu 0000:04:00.0: ... ... [3.748895] [drm] Initialized amdgpu ... ... [18446744073.381141] amdgpu 0000:04:00:0: ... ... [1.613326] igb 0000:03:00.0 enp3s0: ... ... 2. More seriously, some workloads (for example, the test stdlib/test-cxa_atexit2 in the Glibc test suite) triggers an RCU stall and hang the system with a high probably (4 hangs out of 5 tests). Revert this commit to use jiffie on Loongson MIPS systems and fix these issues for now. The root cause may need more investigation. Cc: stable(a)vger.kernel.org # 6.11+ Cc: Jiaxun Yang <jiaxun.yang(a)flygoat.com> Cc: Icenowy Zheng <icenowy(a)aosc.io> Signed-off-by: Xi Ruoyao <xry111(a)xry111.site> --- arch/mips/Kconfig | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 467b10f4361a..5078ebf071ec 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -1084,7 +1084,6 @@ config CSRC_IOASIC config CSRC_R4K select CLOCKSOURCE_WATCHDOG if CPU_FREQ - select HAVE_UNSTABLE_SCHED_CLOCK if SMP && 64BIT bool config CSRC_SB1250 -- 2.47.1

8 months

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[PATCH RESEND] [SCSI] raid class: Fix error handling in raid_component_add

by Ma Ke

The reference count of the device incremented in device_initialize() is not decremented when device_add() fails. Add a put_device() call before returning from the function to decrement reference count for cleanup. Or it could cause memory leak. As comment of device_add() says, if device_add() succeeds, you should call device_del() when you want to get rid of it. If device_add() has not succeeded, use only put_device() to drop the reference count. Found by code review. Cc: stable(a)vger.kernel.org Fixes: ed542bed126c ("[SCSI] raid class: handle component-add errors") Signed-off-by: Ma Ke <make_ruc2021(a)163.com> --- drivers/scsi/raid_class.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/scsi/raid_class.c b/drivers/scsi/raid_class.c index 898a0bdf8df6..2cb2949a78c6 100644 --- a/drivers/scsi/raid_class.c +++ b/drivers/scsi/raid_class.c @@ -251,6 +251,7 @@ int raid_component_add(struct raid_template *r,struct device *raid_dev, list_del(&rc->node); rd->component_count--; put_device(component_dev); + put_device(&rc->dev); kfree(rc); return err; } -- 2.25.1

8 months, 1 week

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[PATCH] ufs: qcom: fix crypto key eviction

by Eric Biggers

From: Eric Biggers <ebiggers(a)google.com> Commit 56541c7c4468 ("scsi: ufs: ufs-qcom: Switch to the new ICE API") introduced an incorrect check of the algorithm ID into the key eviction path, and thus qcom_ice_evict_key() is no longer ever called. Fix it. Fixes: 56541c7c4468 ("scsi: ufs: ufs-qcom: Switch to the new ICE API") Cc: stable(a)vger.kernel.org Cc: Abel Vesa <abel.vesa(a)linaro.org> Signed-off-by: Eric Biggers <ebiggers(a)google.com> --- drivers/ufs/host/ufs-qcom.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c index 68040b2ab5f82..e33ae71245dd0 100644 --- a/drivers/ufs/host/ufs-qcom.c +++ b/drivers/ufs/host/ufs-qcom.c @@ -153,27 +153,25 @@ static int ufs_qcom_ice_program_key(struct ufs_hba *hba, const union ufs_crypto_cfg_entry *cfg, int slot) { struct ufs_qcom_host *host = ufshcd_get_variant(hba); union ufs_crypto_cap_entry cap; - bool config_enable = - cfg->config_enable & UFS_CRYPTO_CONFIGURATION_ENABLE; + + if (!(cfg->config_enable & UFS_CRYPTO_CONFIGURATION_ENABLE)) + return qcom_ice_evict_key(host->ice, slot); /* Only AES-256-XTS has been tested so far. */ cap = hba->crypto_cap_array[cfg->crypto_cap_idx]; if (cap.algorithm_id != UFS_CRYPTO_ALG_AES_XTS || cap.key_size != UFS_CRYPTO_KEY_SIZE_256) return -EOPNOTSUPP; - if (config_enable) - return qcom_ice_program_key(host->ice, - QCOM_ICE_CRYPTO_ALG_AES_XTS, - QCOM_ICE_CRYPTO_KEY_SIZE_256, - cfg->crypto_key, - cfg->data_unit_size, slot); - else - return qcom_ice_evict_key(host->ice, slot); + return qcom_ice_program_key(host->ice, + QCOM_ICE_CRYPTO_ALG_AES_XTS, + QCOM_ICE_CRYPTO_KEY_SIZE_256, + cfg->crypto_key, + cfg->data_unit_size, slot); } #else #define ufs_qcom_ice_program_key NULL base-commit: 7cb1b466315004af98f6ba6c2546bb713ca3c237 -- 2.47.1

8 months, 1 week

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[PATCH v2] arm64: tegra: Fix Tegra234 PCIe interrupt-map

by Brad Griffis

For interrupt-map entries, the DTS specification requires that #address-cells is defined for both the child node and the interrupt parent. For the PCIe interrupt-map entries, the parent node ("gic") has not specified #address-cells. The existing layout of the PCIe interrupt-map entries indicates that it assumes that #address-cells is zero for this node. Explicitly set #address-cells to zero for "gic" so that it complies with the device tree specification. NVIDIA EDK2 works around this issue by assuming #address-cells is zero in this scenario, but that workaround is being removed and so this update is needed or else NVIDIA EDK2 cannot successfully parse the device tree and the board cannot boot. Fixes: ec142c44b026 ("arm64: tegra: Add P2U and PCIe controller nodes to Tegra234 DT") Signed-off-by: Brad Griffis <bgriffis(a)nvidia.com> Cc: stable(a)vger.kernel.org --- v2 * Add "Fixes" and CC stable * Give further context about why the patch is needed arch/arm64/boot/dts/nvidia/tegra234.dtsi | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/boot/dts/nvidia/tegra234.dtsi b/arch/arm64/boot/dts/nvidia/tegra234.dtsi index 984c85eab41a..e1c07c99e9bd 100644 --- a/arch/arm64/boot/dts/nvidia/tegra234.dtsi +++ b/arch/arm64/boot/dts/nvidia/tegra234.dtsi @@ -4010,6 +4010,7 @@ ccplex@e000000 { gic: interrupt-controller@f400000 { compatible = "arm,gic-v3"; + #address-cells = <0>; reg = <0x0 0x0f400000 0x0 0x010000>, /* GICD */ <0x0 0x0f440000 0x0 0x200000>; /* GICR */ interrupt-parent = <&gic>; -- 2.34.1

8 months, 1 week

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[PATCH v2 0/2] rust: lockdep: Fix soundness issue affecting LockClassKeys

by Mitchell Levy

This series is aimed at fixing a soundness issue with how dynamically allocated LockClassKeys are handled. Currently, LockClassKeys can be used without being Pin'd, which can break lockdep since it relies on address stability. Similarly, these keys are not automatically (de)registered with lockdep. At the suggestion of Alice Ryhl, this series includes a patch for -stable kernels that disables dynamically allocated keys. This prevents backported patches from using the unsound implementation. Currently, this series requires that all dynamically allocated LockClassKeys have a lifetime of 'static (i.e., they must be leaked after allocation). This is because Lock does not currently keep a reference to the LockClassKey, instead passing it to C via FFI. This causes a problem because the rust compiler would allow creating a 'static Lock with a 'a LockClassKey (with 'a < 'static) while C would expect the LockClassKey to live as long as the lock. This problem represents an avenue for future work. --- Changes from RFC: - Split into two commits so that dynamically allocated LockClassKeys are removed from stable kernels. (Thanks Alice Ryhl) - Extract calls to C lockdep functions into helpers so things build properly when LOCKDEP=n. (Thanks Benno Lossin) - Remove extraneous `get_ref()` calls. (Thanks Benno Lossin) - Provide better documentation for `new_dynamic()`. (Thanks Benno Lossin) - Ran rustfmt to fix formatting and some extraneous changes. (Thanks Alice Ryhl and Benno Lossin) - Link to RFC: https://lore.kernel.org/r/20240905-rust-lockdep-v1-1-d2c9c21aa8b2@gmail.com --- Changes in v2: - Dropped formatting change that's already fixed upstream (Thanks Dirk Behme). - Moved safety comment to the right point in the patch series (Thanks Dirk Behme and Boqun Feng). - Added an example of dynamic LockClassKey usage (Thanks Boqun Feng). - Link to v1: https://lore.kernel.org/r/20241004-rust-lockdep-v1-0-e9a5c45721fc@gmail.com --- Mitchell Levy (2): rust: lockdep: Remove support for dynamically allocated LockClassKeys rust: lockdep: Use Pin for all LockClassKey usages rust/helpers/helpers.c | 1 + rust/helpers/sync.c | 13 +++++++++ rust/kernel/sync.rs | 63 ++++++++++++++++++++++++++++++++++------- rust/kernel/sync/condvar.rs | 5 ++-- rust/kernel/sync/lock.rs | 9 ++---- rust/kernel/sync/lock/global.rs | 5 ++-- rust/kernel/sync/poll.rs | 2 +- rust/kernel/workqueue.rs | 3 +- 8 files changed, 78 insertions(+), 23 deletions(-) --- base-commit: 0c5928deada15a8d075516e6e0d9ee19011bb000 change-id: 20240905-rust-lockdep-d3e30521c8ba Best regards, -- Mitchell Levy <levymitchell0(a)gmail.com>

8 months, 1 week

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[PATCH v2] samples/landlock: Fix possible NULL dereference in parse_path()

by Gax-c

From: Zichen Xie <zichenxie0106(a)gmail.com> malloc() may return NULL, leading to NULL dereference. Add a NULL check. Fixes: ba84b0bf5a16 ("samples/landlock: Add a sandbox manager example") Signed-off-by: Zichen Xie <zichenxie0106(a)gmail.com> Cc: stable(a)vger.kernel.org --- v2: Modify logic & Add Fixes tag. --- samples/landlock/sandboxer.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/samples/landlock/sandboxer.c b/samples/landlock/sandboxer.c index 57565dfd74a2..ef2a34173d84 100644 --- a/samples/landlock/sandboxer.c +++ b/samples/landlock/sandboxer.c @@ -91,6 +91,9 @@ static int parse_path(char *env_path, const char ***const path_list) } } *path_list = malloc(num_paths * sizeof(**path_list)); + if (*path_list == NULL) + return -1; + for (i = 0; i < num_paths; i++) (*path_list)[i] = strsep(&env_path, ENV_DELIMITER); @@ -127,6 +130,11 @@ static int populate_ruleset_fs(const char *const env_var, const int ruleset_fd, env_path_name = strdup(env_path_name); unsetenv(env_var); num_paths = parse_path(env_path_name, &path_list); + if (num_paths == -1) { + fprintf(stderr, "Failed to allocate memory\n"); + ret = 1; + goto out_free_name; + } if (num_paths == 1 && path_list[0][0] == '\0') { /* * Allows to not use all possible restrictions (e.g. use -- 2.34.1

8 months, 1 week

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[PATCH v2 5/9] btrfs: do proper folio cleanup when run_delalloc_nocow() failed

by Qu Wenruo

[BUG] With CONFIG_DEBUG_VM set, test case generic/476 has some chance to crash with the following VM_BUG_ON_FOLIO(): BTRFS error (device dm-3): cow_file_range failed, start 1146880 end 1253375 len 106496 ret -28 BTRFS error (device dm-3): run_delalloc_nocow failed, start 1146880 end 1253375 len 106496 ret -28 page: refcount:4 mapcount:0 mapping:00000000592787cc index:0x12 pfn:0x10664 aops:btrfs_aops [btrfs] ino:101 dentry name(?):"f1774" flags: 0x2fffff80004028(uptodate|lru|private|node=0|zone=2|lastcpupid=0xfffff) page dumped because: VM_BUG_ON_FOLIO(!folio_test_locked(folio)) ------------[ cut here ]------------ kernel BUG at mm/page-writeback.c:2992! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP CPU: 2 UID: 0 PID: 3943513 Comm: kworker/u24:15 Tainted: G OE 6.12.0-rc7-custom+ #87 Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022 Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs] pc : folio_clear_dirty_for_io+0x128/0x258 lr : folio_clear_dirty_for_io+0x128/0x258 Call trace: folio_clear_dirty_for_io+0x128/0x258 btrfs_folio_clamp_clear_dirty+0x80/0xd0 [btrfs] __process_folios_contig+0x154/0x268 [btrfs] extent_clear_unlock_delalloc+0x5c/0x80 [btrfs] run_delalloc_nocow+0x5f8/0x760 [btrfs] btrfs_run_delalloc_range+0xa8/0x220 [btrfs] writepage_delalloc+0x230/0x4c8 [btrfs] extent_writepage+0xb8/0x358 [btrfs] extent_write_cache_pages+0x21c/0x4e8 [btrfs] btrfs_writepages+0x94/0x150 [btrfs] do_writepages+0x74/0x190 filemap_fdatawrite_wbc+0x88/0xc8 start_delalloc_inodes+0x178/0x3a8 [btrfs] btrfs_start_delalloc_roots+0x174/0x280 [btrfs] shrink_delalloc+0x114/0x280 [btrfs] flush_space+0x250/0x2f8 [btrfs] btrfs_async_reclaim_data_space+0x180/0x228 [btrfs] process_one_work+0x164/0x408 worker_thread+0x25c/0x388 kthread+0x100/0x118 ret_from_fork+0x10/0x20 Code: 910a8021 a90363f7 a9046bf9 94012379 (d4210000) ---[ end trace 0000000000000000 ]--- [CAUSE] The first two lines of extra debug messages show the problem is caused by the error handling of run_delalloc_nocow(). E.g. we have the following dirtied range (4K blocksize 4K page size): 0 16K 32K |//////////////////////////////////////| | Pre-allocated | And the range [0, 16K) has a preallocated extent. - Enter run_delalloc_nocow() for range [0, 16K) Which found range [0, 16K) is preallocated, can do the proper NOCOW write. - Enter fallback_to_fow() for range [16K, 32K) Since the range [16K, 32K) is not backed by preallocated extent, we have to go COW. - cow_file_range() failed for range [16K, 32K) So cow_file_range() will do the clean up by clearing folio dirty, unlock the folios. Now the folios in range [16K, 32K) is unlocked. - Enter extent_clear_unlock_delalloc() from run_delalloc_nocow() Which is called with PAGE_START_WRITEBACK to start page writeback. But folios can only be marked writeback when it's properly locked, thus this triggered the VM_BUG_ON_FOLIO(). Furthermore there is another hidden but common bug that run_delalloc_nocow() is not clearing the folio dirty flags in its error handling path. This is the common bug shared between run_delalloc_nocow() and cow_file_range(). [FIX] - Clear folio dirty for range [@start, @cur_offset) Introduce a helper, cleanup_dirty_folios(), which will find and lock the folio in the range, clear the dirty flag and start/end the writeback, with the extra handling for the @locked_folio. - Introduce a helper to record the last failed COW range end This is to trace which range we should skip, to avoid double unlocking. - Skip the failed COW range for the error handling Cc: stable(a)vger.kernel.org Signed-off-by: Qu Wenruo <wqu(a)suse.com> --- fs/btrfs/inode.c | 93 ++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 86 insertions(+), 7 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 19c88b7d0363..bae8aceb3eae 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1961,6 +1961,48 @@ static int can_nocow_file_extent(struct btrfs_path *path, return ret < 0 ? ret : can_nocow; } +static void cleanup_dirty_folios(struct btrfs_inode *inode, + struct folio *locked_folio, + u64 start, u64 end, int error) +{ + struct btrfs_fs_info *fs_info = inode->root->fs_info; + struct address_space *mapping = inode->vfs_inode.i_mapping; + pgoff_t start_index = start >> PAGE_SHIFT; + pgoff_t end_index = end >> PAGE_SHIFT; + u32 len; + + ASSERT(end + 1 - start < U32_MAX); + ASSERT(IS_ALIGNED(start, fs_info->sectorsize) && + IS_ALIGNED(end + 1, fs_info->sectorsize)); + len = end + 1 - start; + + /* + * Handle the locked folio first. + * btrfs_folio_clamp_*() helpers can handle range out of the folio case. + */ + btrfs_folio_clamp_clear_dirty(fs_info, locked_folio, start, len); + btrfs_folio_clamp_set_writeback(fs_info, locked_folio, start, len); + btrfs_folio_clamp_clear_writeback(fs_info, locked_folio, start, len); + + for (pgoff_t index = start_index; index <= end_index; index++) { + struct folio *folio; + + /* Already handled at the beginning. */ + if (index == locked_folio->index) + continue; + folio = __filemap_get_folio(mapping, index, FGP_LOCK, GFP_NOFS); + /* Cache already dropped, no need to do any cleanup. */ + if (IS_ERR(folio)) + continue; + btrfs_folio_clamp_clear_dirty(fs_info, folio, start, len); + btrfs_folio_clamp_set_writeback(fs_info, folio, start, len); + btrfs_folio_clamp_clear_writeback(fs_info, folio, start, len); + folio_unlock(folio); + folio_put(folio); + } + mapping_set_error(mapping, error); +} + /* * when nowcow writeback call back. This checks for snapshots or COW copies * of the extents that exist in the file, and COWs the file as required. @@ -1976,6 +2018,11 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode, struct btrfs_root *root = inode->root; struct btrfs_path *path; u64 cow_start = (u64)-1; + /* + * If not 0, represents the inclusive end of the last fallback_to_cow() + * range. Only for error handling. + */ + u64 cow_end = 0; u64 cur_offset = start; int ret; bool check_prev = true; @@ -2136,6 +2183,7 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode, found_key.offset - 1); cow_start = (u64)-1; if (ret) { + cow_end = found_key.offset - 1; btrfs_dec_nocow_writers(nocow_bg); goto error; } @@ -2209,11 +2257,12 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode, cow_start = cur_offset; if (cow_start != (u64)-1) { - cur_offset = end; ret = fallback_to_cow(inode, locked_folio, cow_start, end); cow_start = (u64)-1; - if (ret) + if (ret) { + cow_end = end; goto error; + } } btrfs_free_path(path); @@ -2221,12 +2270,42 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode, error: /* - * If an error happened while a COW region is outstanding, cur_offset - * needs to be reset to cow_start to ensure the COW region is unlocked - * as well. + * There are several error cases: + * + * 1) Failed without falling back to COW + * start cur_start end + * |/////////////| | + * + * For range [start, cur_start) the folios are already unlocked (except + * @locked_folio), EXTENT_DELALLOC already removed. + * Only need to clear the dirty flag as they will never be submitted. + * Ordered extent and extent maps are handled by + * btrfs_mark_ordered_io_finished() inside run_delalloc_range(). + * + * 2) Failed with error from fallback_to_cow() + * start cur_start cow_end end + * |/////////////|-----------| | + * + * For range [start, cur_start) it's the same as case 1). + * But for range [cur_start, cow_end), the folios have dirty flag + * cleared and unlocked, EXTENT_DEALLLOC cleared. + * There may or may not be any ordered extents/extent maps allocated. + * + * We should not call extent_clear_unlock_delalloc() on range [cur_start, + * cow_end), as the folios are already unlocked. + * + * So clear the folio dirty flags for [start, cur_offset) first. */ - if (cow_start != (u64)-1) - cur_offset = cow_start; + if (cur_offset > start) + cleanup_dirty_folios(inode, locked_folio, start, cur_offset - 1, ret); + + /* + * If an error happened while a COW region is outstanding, cur_offset + * needs to be reset to @cow_end + 1 to skip the COW range, as + * cow_file_range() will do the proper cleanup at error. + */ + if (cow_end) + cur_offset = cow_end + 1; /* * We need to lock the extent here because we're clearing DELALLOC and -- 2.47.1

8 months, 1 week

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[PATCH v2 4/9] btrfs: do proper folio cleanup when cow_file_range() failed

by Qu Wenruo

[BUG] When testing with COW fixup marked as BUG_ON() (this is involved with the new pin_user_pages*() change, which should not result new out-of-band dirty pages), I hit a crash triggered by the BUG_ON() from hitting COW fixup path. This BUG_ON() happens just after a failed btrfs_run_delalloc_range(): BTRFS error (device dm-2): failed to run delalloc range, root 348 ino 405 folio 65536 submit_bitmap 6-15 start 90112 len 106496: -28 ------------[ cut here ]------------ kernel BUG at fs/btrfs/extent_io.c:1444! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP CPU: 0 UID: 0 PID: 434621 Comm: kworker/u24:8 Tainted: G OE 6.12.0-rc7-custom+ #86 Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022 Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs] pc : extent_writepage_io+0x2d4/0x308 [btrfs] lr : extent_writepage_io+0x2d4/0x308 [btrfs] Call trace: extent_writepage_io+0x2d4/0x308 [btrfs] extent_writepage+0x218/0x330 [btrfs] extent_write_cache_pages+0x1d4/0x4b0 [btrfs] btrfs_writepages+0x94/0x150 [btrfs] do_writepages+0x74/0x190 filemap_fdatawrite_wbc+0x88/0xc8 start_delalloc_inodes+0x180/0x3b0 [btrfs] btrfs_start_delalloc_roots+0x174/0x280 [btrfs] shrink_delalloc+0x114/0x280 [btrfs] flush_space+0x250/0x2f8 [btrfs] btrfs_async_reclaim_data_space+0x180/0x228 [btrfs] process_one_work+0x164/0x408 worker_thread+0x25c/0x388 kthread+0x100/0x118 ret_from_fork+0x10/0x20 Code: aa1403e1 9402f3ef aa1403e0 9402f36f (d4210000) ---[ end trace 0000000000000000 ]--- [CAUSE] That failure is mostly from cow_file_range(), where we can hit -ENOSPC. Although the -ENOSPC is already a bug related to our space reservation code, let's just focus on the error handling. For example, we have the following dirty range [0, 64K) of an inode, with 4K sector size and 4K page size: 0 16K 32K 48K 64K |///////////////////////////////////////| |#######################################| Where |///| means page are still dirty, and |###| means the extent io tree has EXTENT_DELALLOC flag. - Enter extent_writepage() for page 0 - Enter btrfs_run_delalloc_range() for range [0, 64K) - Enter cow_file_range() for range [0, 64K) - Function btrfs_reserve_extent() only reserved one 16K extent So we created extent map and ordered extent for range [0, 16K) 0 16K 32K 48K 64K |////////|//////////////////////////////| |<- OE ->|##############################| And range [0, 16K) has its delalloc flag cleared. But since we haven't yet submit any bio, involved 4 pages are still dirty. - Function btrfs_reserve_extent() return with -ENOSPC Now we have to run error cleanup, which will clear all EXTENT_DELALLOC* flags and clear the dirty flags for the remaining ranges: 0 16K 32K 48K 64K |////////| | | | | Note that range [0, 16K) still has their pages dirty. - Some time later, writeback are triggered again for the range [0, 16K) since the page range still have dirty flags. - btrfs_run_delalloc_range() will do nothing because there is no EXTENT_DELALLOC flag. - extent_writepage_io() find page 0 has no ordered flag Which falls into the COW fixup path, triggering the BUG_ON(). Unfortunately this error handling bug dates back to the introduction of btrfs. Thankfully with the abuse of cow fixup, at least it won't crash the kernel. [FIX] Instead of immediately unlock the extent and folios, we keep the extent and folios locked until either erroring out or the whole delalloc range finished. When the whole delalloc range finished without error, we just unlock the whole range with PAGE_SET_ORDERED (and PAGE_UNLOCK for !keep_locked cases), with EXTENT_DELALLOC and EXTENT_LOCKED cleared. And those involved folios will be properly submitted, with their dirty flags cleared during submission. For the error path, it will be a little more complex: - The range with ordered extent allocated (range (1)) We only clear the EXTENT_DELALLOC and EXTENT_LOCKED, as the remaining flags are cleaned up by btrfs_mark_ordered_io_finished()->btrfs_finish_one_ordered(). For folios we finish the IO (clear dirty, start writeback and immediately finish the writeback) and unlock the folios. - The range with reserved extent but no ordered extent (range(2)) - The range we never touched (range(3)) For both range (2) and range(3) the behavior is not changed. Now even if cow_file_range() failed halfway with some successfully reserved extents/ordered extents, we will keep all folios clean, so there will be no future writeback triggered on them. Cc: stable(a)vger.kernel.org Signed-off-by: Qu Wenruo <wqu(a)suse.com> --- fs/btrfs/inode.c | 65 ++++++++++++++++++++++++------------------------ 1 file changed, 32 insertions(+), 33 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 5ba8d044757b..19c88b7d0363 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1364,6 +1364,17 @@ static noinline int cow_file_range(struct btrfs_inode *inode, alloc_hint = btrfs_get_extent_allocation_hint(inode, start, num_bytes); + /* + * We're not doing compressed IO, don't unlock the first page + * (which the caller expects to stay locked), don't clear any + * dirty bits and don't set any writeback bits + * + * Do set the Ordered (Private2) bit so we know this page was + * properly setup for writepage. + */ + page_ops = (keep_locked ? 0 : PAGE_UNLOCK); + page_ops |= PAGE_SET_ORDERED; + /* * Relocation relies on the relocated extents to have exactly the same * size as the original extents. Normally writeback for relocation data @@ -1423,6 +1434,10 @@ static noinline int cow_file_range(struct btrfs_inode *inode, file_extent.offset = 0; file_extent.compression = BTRFS_COMPRESS_NONE; + /* + * Locked range will be released either during error clean up or + * after the whole range is finished. + */ lock_extent(&inode->io_tree, start, start + cur_alloc_size - 1, &cached); @@ -1468,21 +1483,6 @@ static noinline int cow_file_range(struct btrfs_inode *inode, btrfs_dec_block_group_reservations(fs_info, ins.objectid); - /* - * We're not doing compressed IO, don't unlock the first page - * (which the caller expects to stay locked), don't clear any - * dirty bits and don't set any writeback bits - * - * Do set the Ordered flag so we know this page was - * properly setup for writepage. - */ - page_ops = (keep_locked ? 0 : PAGE_UNLOCK); - page_ops |= PAGE_SET_ORDERED; - - extent_clear_unlock_delalloc(inode, start, start + cur_alloc_size - 1, - locked_folio, &cached, - EXTENT_LOCKED | EXTENT_DELALLOC, - page_ops); if (num_bytes < cur_alloc_size) num_bytes = 0; else @@ -1499,6 +1499,9 @@ static noinline int cow_file_range(struct btrfs_inode *inode, if (ret) goto out_unlock; } + extent_clear_unlock_delalloc(inode, orig_start, end, locked_folio, &cached, + EXTENT_LOCKED | EXTENT_DELALLOC, + page_ops); done: if (done_offset) *done_offset = end; @@ -1519,35 +1522,31 @@ static noinline int cow_file_range(struct btrfs_inode *inode, * We process each region below. */ - clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW | - EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV; - page_ops = PAGE_UNLOCK | PAGE_START_WRITEBACK | PAGE_END_WRITEBACK; - /* * For the range (1). We have already instantiated the ordered extents * for this region. They are cleaned up by * btrfs_cleanup_ordered_extents() in e.g, - * btrfs_run_delalloc_range(). EXTENT_LOCKED | EXTENT_DELALLOC are - * already cleared in the above loop. And, EXTENT_DELALLOC_NEW | - * EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV are handled by the cleanup - * function. + * btrfs_run_delalloc_range(). + * EXTENT_DELALLOC_NEW | EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV + * are also handled by the cleanup function. * - * However, in case of @keep_locked, we still need to unlock the pages - * (except @locked_folio) to ensure all the pages are unlocked. + * So here we only clear EXTENT_LOCKED and EXTENT_DELALLOC flag, + * and finish the writeback of the involved folios, which will be + * never submitted. */ - if (keep_locked && orig_start < start) { + if (orig_start < start) { + clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC; + page_ops = PAGE_UNLOCK | PAGE_START_WRITEBACK | PAGE_END_WRITEBACK; + if (!locked_folio) mapping_set_error(inode->vfs_inode.i_mapping, ret); extent_clear_unlock_delalloc(inode, orig_start, start - 1, - locked_folio, NULL, 0, page_ops); + locked_folio, NULL, clear_bits, page_ops); } - /* - * At this point we're unlocked, we want to make sure we're only - * clearing these flags under the extent lock, so lock the rest of the - * range and clear everything up. - */ - lock_extent(&inode->io_tree, start, end, NULL); + clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW | + EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV; + page_ops = PAGE_UNLOCK | PAGE_START_WRITEBACK | PAGE_END_WRITEBACK; /* * For the range (2). If we reserved an extent for our delalloc range -- 2.47.1

8 months, 1 week

2
2
0 0

[PATCH v2 2/9] btrfs: fix double accounting race when extent_writepage_io() failed

by Qu Wenruo

[BUG] If submit_one_sector() failed inside extent_writepage_io() for sector size < page size cases (e.g. 4K sector size and 64K page size), then we can hit double ordered extent accounting error. This should be very rare, as submit_one_sector() only fails when we failed to grab the extent map, and such extent map should exist inside the memory and have been pinned. [CAUSE] For example we have the following folio layout: 0 4K 32K 48K 60K 64K |//| |//////| |///| Where |///| is the dirty range we need to writeback. The 3 different dirty ranges are submitted for regular COW. Now we hit the following sequence: - submit_one_sector() returned 0 for [0, 4K) - submit_one_sector() returned 0 for [32K, 48K) - submit_one_sector() returned error for [60K, 64K) - btrfs_mark_ordered_io_finished() called for the whole folio This will mark the following ranges as finished: * [0, 4K) * [32K, 48K) Both ranges have their IO already submitted, this cleanup will lead to double accounting. * [60K, 64K) That's the correct cleanup. The only good news is, this error is only theoretical, as the target extent map is always pinned, thus we should directly grab it from memory, other than reading it from the disk. [FIX] Instead of calling btrfs_mark_ordered_io_finished() for the whole folio range, which can touch ranges we should not touch, instead move the error handling inside extent_writepage_io(). So that we can cleanup exact sectors that are ought to be submitted but failed. This provide much more accurate cleanup, avoiding the double accounting. Cc: stable(a)vger.kernel.org # 5.15+ Signed-off-by: Qu Wenruo <wqu(a)suse.com> --- fs/btrfs/extent_io.c | 32 +++++++++++++++++++------------- 1 file changed, 19 insertions(+), 13 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 417c710c55ca..b6a4f1765b4c 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -1418,6 +1418,7 @@ static noinline_for_stack int extent_writepage_io(struct btrfs_inode *inode, struct btrfs_fs_info *fs_info = inode->root->fs_info; unsigned long range_bitmap = 0; bool submitted_io = false; + bool error = false; const u64 folio_start = folio_pos(folio); u64 cur; int bit; @@ -1460,11 +1461,21 @@ static noinline_for_stack int extent_writepage_io(struct btrfs_inode *inode, break; } ret = submit_one_sector(inode, folio, cur, bio_ctrl, i_size); - if (ret < 0) - goto out; + if (unlikely(ret < 0)) { + submit_one_bio(bio_ctrl); + /* + * Failed to grab the extent map which should be very rare. + * Since there is no bio submitted to finish the ordered + * extent, we have to manually finish this sector. + */ + btrfs_mark_ordered_io_finished(inode, folio, cur, + fs_info->sectorsize, false); + error = true; + continue; + } submitted_io = true; } -out: + /* * If we didn't submitted any sector (>= i_size), folio dirty get * cleared but PAGECACHE_TAG_DIRTY is not cleared (only cleared @@ -1472,8 +1483,11 @@ static noinline_for_stack int extent_writepage_io(struct btrfs_inode *inode, * * Here we set writeback and clear for the range. If the full folio * is no longer dirty then we clear the PAGECACHE_TAG_DIRTY tag. + * + * If we hit any error, the corresponding sector will still be dirty + * thus no need to clear PAGECACHE_TAG_DIRTY. */ - if (!submitted_io) { + if (!submitted_io && !error) { btrfs_folio_set_writeback(fs_info, folio, start, len); btrfs_folio_clear_writeback(fs_info, folio, start, len); } @@ -1493,7 +1507,6 @@ static int extent_writepage(struct folio *folio, struct btrfs_bio_ctrl *bio_ctrl { struct inode *inode = folio->mapping->host; struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); - const u64 page_start = folio_pos(folio); int ret; size_t pg_offset; loff_t i_size = i_size_read(inode); @@ -1536,10 +1549,6 @@ static int extent_writepage(struct folio *folio, struct btrfs_bio_ctrl *bio_ctrl bio_ctrl->wbc->nr_to_write--; - if (ret) - btrfs_mark_ordered_io_finished(BTRFS_I(inode), folio, - page_start, PAGE_SIZE, !ret); - done: if (ret < 0) mapping_set_error(folio->mapping, ret); @@ -2319,11 +2328,8 @@ void extent_write_locked_range(struct inode *inode, const struct folio *locked_f if (ret == 1) goto next_page; - if (ret) { - btrfs_mark_ordered_io_finished(BTRFS_I(inode), folio, - cur, cur_len, !ret); + if (ret) mapping_set_error(mapping, ret); - } btrfs_folio_end_lock(fs_info, folio, cur, cur_len); if (ret < 0) found_error = true; -- 2.47.1

8 months, 1 week

3
5
0 0

[PATCH] drm/xe/client: Better correlate exec_queue and GT timestamps

by Lucas De Marchi

This partially reverts commit fe4f5d4b6616 ("drm/xe: Clean up VM / exec queue file lock usage."). While it's desired to have the mutex to protect only the reference to the exec queue, getting and dropping each mutex and then later getting the GPU timestamp, doesn't produce a correct result: it introduces multiple opportunities for the task to be scheduled out and thus wrecking havoc the deltas reported to userspace. Also, to better correlate the timestamp from the exec queues with the GPU, disable preemption so they can be updated without allowing the task to be scheduled out. We leave interrupts enabled as that shouldn't be enough disturbance for the deltas to matter to userspace. Test scenario: * IGT'S `xe_drm_fdinfo --r --r utilization-single-full-load` * Platform: LNL, where CI occasionally reports failures * `stress -c $(nproc)` running in parallel to disturb the system This brings a first failure from "after ~150 executions" to "never occurs after 1000 attempts". Cc: stable(a)vger.kernel.org # v6.11+ Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/3512 Signed-off-by: Lucas De Marchi <lucas.demarchi(a)intel.com> --- drivers/gpu/drm/xe/xe_drm_client.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/xe/xe_drm_client.c b/drivers/gpu/drm/xe/xe_drm_client.c index 298a587da7f17..e307b4d6bab5a 100644 --- a/drivers/gpu/drm/xe/xe_drm_client.c +++ b/drivers/gpu/drm/xe/xe_drm_client.c @@ -338,15 +338,12 @@ static void show_run_ticks(struct drm_printer *p, struct drm_file *file) /* Accumulate all the exec queues from this client */ mutex_lock(&xef->exec_queue.lock); - xa_for_each(&xef->exec_queue.xa, i, q) { - xe_exec_queue_get(q); - mutex_unlock(&xef->exec_queue.lock); + preempt_disable(); + xa_for_each(&xef->exec_queue.xa, i, q) xe_exec_queue_update_run_ticks(q); - mutex_lock(&xef->exec_queue.lock); - xe_exec_queue_put(q); - } + preempt_enable(); mutex_unlock(&xef->exec_queue.lock); gpu_timestamp = xe_hw_engine_read_timestamp(hwe); -- 2.47.0

8 months, 1 week

3
12
0 0

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