On Tue, Jun 23, 2026 at 1:11 PM Yoann Congal <[email protected]> wrote:
> > > > Le mar. 23 juin 2026, 19:00, Bruce Ashfield <[email protected]> a > écrit : > >> >> >> On Tue, Jun 23, 2026 at 12:21 PM Yoann Congal <[email protected]> >> wrote: >> >>> On Wed Jun 10, 2026 at 6:49 PM CEST, Bruce Ashfield via >>> lists.openembedded.org wrote: >>> > From: Bruce Ashfield <[email protected]> >>> > >>> > Updating linux-yocto/6.6 to the latest korg -stable release that >>> comprises >>> > the following commits: >>> > >>> > c09fbcd31ae6 Linux 6.6.130 >>> > [...] >>> > dc7c9b9d03a5 ext4: drop extent cache when splitting extent fails >>> > f0931a5c1700 ext4: drop extent cache after doing PARTIAL_VALID1 >>> zeroout >>> > 67cdb7bd7442 ext4: don't set EXT4_GET_BLOCKS_CONVERT when >>> splitting before submitting I/O >>> > 11406eb96a19 ext4: correct the comments place for >>> EXT4_EXT_MAY_ZEROOUT >>> >>> Hello Bruce, >>> >>> > ed0096fc86b2 ext4: get rid of ppath in >>> ext4_ext_handle_unwritten_extents() >>> > d7b04ea31c6e ext4: get rid of ppath in >>> ext4_ext_convert_to_initialized() >>> > c24ce099bea9 ext4: get rid of ppath in >>> ext4_convert_unwritten_extents_endio() >>> > 147a6a2725b1 ext4: get rid of ppath in ext4_split_convert_extents() >>> > cda8a34348d7 ext4: get rid of ppath in ext4_split_extent() >>> > 58ddae5d77b1 ext4: don't zero the entire extent if >>> EXT4_EXT_DATA_PARTIAL_VALID1 >>> > e766534911b3 ext4: subdivide EXT4_EXT_DATA_VALID1 >>> > ffb68fc57207 ext4: get rid of ppath in ext4_split_extent_at() >>> > fb138df7d886 ext4: get rid of ppath in ext4_ext_insert_extent() >>> > 8f6e910852d8 ext4: get rid of ppath in ext4_ext_create_new_leaf() >>> > cafb151eb180 ext4: get rid of ppath in ext4_find_extent() >>> >>> (The following was found by Gemini, but I've checked it) >>> >>> Looks like these commits introduced a bug causing an intermittent LTP >>> regression: >>> https://autobuilder.yoctoproject.org/valkyrie/#/builders/98/builds/3837 >>> -> >>> https://valkyrie.yocto.io/pub/non-release/20260622-121/testresults/qemuarm64-ltp/core-image-sato/qemu_boot_log.20260623002740 >>> >>> [ 6952.500858] Unable to handle kernel paging request at virtual address >>> ffffffffffffffec >>> [ 6952.503768] Mem abort info: >>> [ 6952.504431] ESR = 0x0000000096000005 >>> [ 6952.505333] EC = 0x25: DABT (current EL), IL = 32 bits >>> [ 6952.506541] SET = 0, FnV = 0 >>> [ 6952.507354] EA = 0, S1PTW = 0 >>> [ 6952.508154] FSC = 0x05: level 1 translation fault >>> [ 6952.509208] Data abort info: >>> [ 6952.509849] ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 >>> [ 6952.511175] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 >>> [ 6952.512372] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 >>> [ 6952.513667] swapper pgtable: 4k pages, 39-bit VAs, >>> pgdp=0000000041250000 >>> [ 6952.514909] [ffffffffffffffec] pgd=0000000000000000, >>> p4d=0000000000000000, pud=0000000000000000 >>> [ 6952.516423] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP >>> [ 6952.517503] Modules linked in: x_tables tun loop [last unloaded: >>> ip6_tables] >>> [ 6952.518691] CPU: 1 PID: 1078 Comm: kworker/u12:1 Tainted: G W >>> 6.6.142-yocto-standard #1 >>> [ 6952.520269] Hardware name: linux,dummy-virt (DT) >>> [ 6952.521094] Workqueue: writeback wb_workfn (flush-7:0) >>> [ 6952.521985] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS >>> BTYPE=--) >>> [ 6952.523184] pc : ext4_ext_map_blocks+0x260/0x1860 >>> [ 6952.524011] lr : ext4_ext_map_blocks+0xdb8/0x1860 >>> [ 6952.524851] sp : ffffffc086a3b620 >>> [ 6952.525421] x29: ffffffc086a3b740 x28: ffffffffffffffe4 x27: >>> 000000000000808c >>> [ 6952.526624] x26: ffffff8017dd9000 x25: 000000000000808c x24: >>> 0000000000000002 >>> [ 6952.527849] x23: ffffff8035e766c8 x22: ffffff802e589690 x21: >>> 000000000000042f >>> [ 6952.529087] x20: ffffffc086a3b948 x19: ffffff8035e767f0 x18: >>> 0000000000000000 >>> [ 6952.530310] x17: ffffffc081691310 x16: fffffffe001ab548 x15: >>> 0000005564d4cb48 >>> [ 6952.531519] x14: 00000000ffffffff x13: 0000000000000000 x12: >>> ffffffffffffffc0 >>> [ 6952.532683] x11: 0000000000000040 x10: ffffff8005d81d80 x9 : >>> ffffffc0803cce14 >>> [ 6952.533886] x8 : 00000000bab647bc x7 : 0000000000000000 x6 : >>> 000000000000d847 >>> [ 6952.535065] x5 : 0000000000000000 x4 : 0000000000316019 x3 : >>> 0000000000000000 >>> [ 6952.536264] x2 : 0000000000000000 x1 : 0000000000000000 x0 : >>> ffffff803deec880 >>> [ 6952.537425] Call trace: >>> [ 6952.537860] ext4_ext_map_blocks+0x260/0x1860 >>> [ 6952.538589] ext4_map_blocks+0x19c/0x598 >>> [ 6952.539258] ext4_do_writepages+0x5a4/0xbe0 >>> [ 6952.539977] ext4_writepages+0x84/0x110 >>> [ 6952.540624] do_writepages+0x94/0x1e0 >>> [ 6952.541240] __writeback_single_inode+0x60/0x4d8 >>> [ 6952.542086] writeback_sb_inodes+0x208/0x4b0 >>> [ 6952.542812] __writeback_inodes_wb+0x58/0x118 >>> [ 6952.543578] wb_writeback+0x274/0x440 >>> [ 6952.544198] wb_workfn+0x3b0/0x5c8 >>> [ 6952.544788] process_one_work+0x16c/0x3e0 >>> [ 6952.545434] worker_thread+0x1b4/0x378 >>> [ 6952.546059] kthread+0x118/0x128 >>> [ 6952.546599] ret_from_fork+0x10/0x20 >>> [ 6952.547197] Code: 2a0103f9 b9009fe1 b9000e99 b40055fc (79401398) >>> [ 6952.548170] ---[ end trace 0000000000000000 ]--- >>> [ 6952.551090] ------------[ cut here ]------------ >>> >>> Reading the resulting code in 6.6.142: >>> fs/ext4/extents.c: >>> int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, >>> struct ext4_map_blocks *map, int flags) >>> { >>> struct ext4_ext_path *path = NULL; >>> // ... >>> >>> got_allocated_blocks: >>> path = ext4_ext_insert_extent(handle, inode, path, &newex, >>> flags); >>> if (IS_ERR(path)) { >>> err = PTR_ERR(path); >>> /* >>> * Gracefully handle out of space conditions. If the >>> filesystem >>> * is inconsistent, we'll just leak allocated blocks to >>> avoid >>> * causing even more damage. >>> */ >>> // ... >>> goto out; >>> } >>> >>> // ... >>> out: >>> ext4_free_ext_path(path); >>> >>> trace_ext4_ext_map_blocks_exit(inode, flags, map, >>> err ? err : allocated); >>> return err ? err : allocated; >>> } >>> >>> => Under out of space condition (what LTP does a *LOT*): path is given >>> unmodified to >>> ext4_free_ext_path() that only does a NULL check (no IS_ERR) before >>> dereferencing it. And that produces the oops and then, the LTP failure. >>> >>> Notably, master commit 6b854d552711 ("ext4: get rid of ppath in >>> get_ext_path()") >>> never got backported to 6.6.y. But does add the IS_ERR_OR_NULL() check >>> to ext4_free_ext_path: >>> void ext4_free_ext_path(struct ext4_ext_path *path) >>> { >>> + if (IS_ERR_OR_NULL(path)) >>> + return; >>> >>> Bruce, what do you think? Should we backport >>> 6b854d552711·("ext4:·get·rid·of·ppath·in·get_ext_path()")? Ask for it to >>> be backported? >>> >> >> It's possible. But without being able to reproduce the issues locally, >> I'm just >> guessing. >> >> I wouldn't just backport it, I'd suggest that -stable pick it up as well, >> but then >> I'm back to not being able to see any issues locally. I wouldn't ask for >> a >> backport without knowing it does fix the issues. >> >> I'm happy to cherry-pick it as a shot in the dark, but that's all it >> would be :) >> > > I could setup AB to repeatedly test with/without the cherry-pick (only the > fs section of ltp). I suspect the frequency of the bug triggering is quite > high and that would prove the fix, enough to convince you and -stable? > > Even enough runs with no failure is probably enough, given that you've already been seeing it on the AB. That could be our "before" sample set. I can cherry-pick it and send SRCREV bump to the 6.6 recipes in the scenario I'm suggesting that should be all you need. Bruce > >> Bruce >> >> >> >>> >>> Thanks for your help! >>> -- >>> Yoann Congal >>> Smile ECS >>> >>> >> >> -- >> - Thou shalt not follow the NULL pointer, for chaos and madness await >> thee at its end >> - "Use the force Harry" - Gandalf, Star Trek II >> >> -- - Thou shalt not follow the NULL pointer, for chaos and madness await thee at its end - "Use the force Harry" - Gandalf, Star Trek II
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