On 2016-02-21, at 1:13 PM, James Bottomley wrote: > On Sun, 2016-02-21 at 13:09 -0500, John David Anglin wrote: >> On 2016-02-20, at 10:47 PM, James Bottomley wrote: >> >>> On Sat, 2016-02-20 at 21:52 -0500, John David Anglin wrote: >>>> On 2016-02-20, at 5:52 PM, John David Anglin wrote: >>>> >>>>> On 2016-02-20, at 4:59 PM, Helge Deller wrote: >>>>> >>>>>> On 20.02.2016 21:43, John David Anglin wrote: >>>>>>> On 2016-02-20, at 3:13 PM, John David Anglin wrote: >>>>>>> >>>>>>>> On 2016-01-23, at 1:00 PM, John David Anglin wrote: >>>>>>>> >>>>>>>>> WARNING: at block/blk-merge.c:454 >>>>>>>> >>>>>>>> With linux-image-4.4.0-1-parisc64-smp on c3740, the above >>>>>>>> warning is the last message I see. >>>>>>>> Kernel seems to hang at that point. This is warning >>>>>>>> code: >>>>>>>> >>>>>>>> /* >>>>>>>> * Something must have been wrong if the figured >>>>>>>> number >>>>>>>> of >>>>>>>> * segment is bigger than number of req's physical >>>>>>>> segments >>>>>>>> */ >>>>>>>> WARN_ON(nsegs > rq->nr_phys_segments); >>>>>>> >>>>>>> On Sep. 12, 2015, I reported the following problem: >>>>>>> >>>>>>> http://www.spinics.net/lists/linux-parisc/msg06327.html >>>>>> >>>>>> The problem is still, that this bug can only be reproduced at >>>>>> every boot when then >>>>>> scsi drivers are built as modules (and in an initrd). I could >>>>>> never reproduce it when >>>>>> I booted a kernel with built-in scsi drivers. >>>>>> >>>>>> The bug seems to be triggered by(*nsegs)++ command in >>>>>> __blk_segment_map_sg() in block/blk-merge.c. >>>>>> I'm testing with the 4.4.2 kernel from debian. >>>>>> I modified __blk_segment_map_sg() like that: >>>>>> static inline void >>>>>> __blk_segment_map_sg(struct request_queue *q, struct bio_vec >>>>>> *bvec, >>>>>> struct scatterlist *sglist, struct bio_vec >>>>>> *bvprv, >>>>>> struct scatterlist **sg, int *nsegs, int >>>>>> *cluster) >>>>>> { >>>>>> >>>>>> int nbytes = bvec->bv_len; >>>>>> >>>>>> if (*sg && *cluster) { >>>>>> if ((*sg)->length + nbytes > >>>>>> queue_max_segment_size(q)) >>>>>> goto new_segment; >>>>>> >>>>>> if (!BIOVEC_PHYS_MERGEABLE(bvprv, bvec)) >>>>>> goto new_segment; >>>>>> if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bvec)) >>>>>> goto new_segment; >>>>>> >>>>>> (*sg)->length += nbytes; >>>>>> } else { >>>>>> new_segment: >>>>>> if (*sg && *cluster) { >>>>>> printk("NEW SEGMENT sg = %p!!!\n", sg); >>>>>> printk("__blk_segment_map_sg: length = >>>>>> %d, >>>>>> nbytes = %d, sum = %d > %d\n", (*sg)->length, nbytes, (*sg) >>>>>> ->length + nbytes, queue_max_segment_size(q)); >>>>>> printk("__blk_segment_map_sg: >>>>>> BIOVEC_PHYS_MERGEABLE = %d, BIOVEC_SEG_BOUNDARY = %d\n", >>>>>> BIOVEC_PHYS_MERGEABLE(bvprv, bvec), BIOVEC_SEG_BOUNDARY(q, >>>>>> bvprv, >>>>>> bvec) ); >>>>>> } >>>>>> if (!*sg) >>>>>> *sg = sglist; >>>>>> else { >>>>>> /* >>>>>> * If the driver previously mapped a >>>>>> shorter >>>>>> * list, we could see a termination bit >>>>>> * prematurely unless it fully inits the >>>>>> sg >>>>>> * table on each mapping. We KNOW that >>>>>> there >>>>>> * must be more entries here or the >>>>>> driver >>>>>> * would be buggy, so force clear the >>>>>> * termination bit to avoid doing a full >>>>>> * sg_init_table() in drivers for each >>>>>> command. >>>>>> */ >>>>>> sg_unmark_end(*sg); >>>>>> *sg = sg_next(*sg); >>>>>> } >>>>>> >>>>>> sg_set_page(*sg, bvec->bv_page, nbytes, bvec >>>>>> ->bv_offset); >>>>>> (*nsegs)++; >>>>>> } >>>>>> *bvprv = *bvec; >>>>>> } >>>>>> >>>>>> The boot log looks then like this: >>>>>> [ 43.044000] scsi_init_sgtable: count = 1, nents = 1 >>>>>> (there are lots of those before it!) >>>>>> [ 43.164000] scsi_init_sgtable: nr_phys_segments = 1 >>>>>> [ 43.164000] scsi_init_sgtable: count = 1, nents = 1 >>>>>> [ 43.280000] scsi_init_sgtable: nr_phys_segments = 1 >>>>>> [ 43.280000] scsi_init_sgtable: count = 1, nents = 1 >>>>>> [ 43.396000] scsi_init_sgtable: nr_phys_segments = 1 >>>>>> [ 43.396000] scsi_init_sgtable: count = 1, nents = 1 >>>>>> [ 43.512000] scsi_init_sgtable: nr_phys_segments = 1 >>>>>> [ 43.512000] scsi_init_sgtable: count = 1, nents = 1 >>>>>> [ 43.628000] scsi_init_sgtable: nr_phys_segments = 3 >>>>>> [ 43.628000] NEW SEGMENT sg = 000000007fa911e8!!! >>>>>> [ 43.628000] __blk_segment_map_sg: length = 4096, nbytes = >>>>>> 4096, sum = 8192 > 65536 >>>>>> [ 43.628000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 43.628000] NEW SEGMENT sg = 000000007fa911e8!!! >>>>>> [ 43.628000] __blk_segment_map_sg: length = 4096, nbytes = >>>>>> 4096, sum = 8192 > 65536 >>>>>> [ 43.628000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 43.628000] scsi_init_sgtable: count = 3, nents = 3 >>>>>> [ 44.224000] scsi_init_sgtable: nr_phys_segments = 1 >>>>>> [ 44.224000] scsi_init_sgtable: count = 1, nents = 1 >>>>>> [ 44.340000] scsi_init_sgtable: nr_phys_segments = 1 >>>>>> [ 44.340000] scsi_init_sgtable: count = 1, nents = 1 >>>>>> [ 44.456000] scsi_init_sgtable: nr_phys_segments = 7 >>>>>> [ 44.456000] NEW SEGMENT sg = 00000000bfca0f98!!! >>>>>> [ 44.456000] __blk_segment_map_sg: length = 4096, nbytes = >>>>>> 4096, sum = 8192 > 65536 >>>>>> [ 44.456000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 44.456000] NEW SEGMENT sg = 00000000bfca0f98!!! >>>>>> [ 44.456000] __blk_segment_map_sg: length = 4096, nbytes = >>>>>> 4096, sum = 8192 > 65536 >>>>>> [ 44.456000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 44.456000] NEW SEGMENT sg = 00000000bfca0f98!!! >>>>>> [ 44.456000] __blk_segment_map_sg: length = 4096, nbytes = >>>>>> 4096, sum = 8192 > 65536 >>>>>> [ 44.456000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 44.456000] NEW SEGMENT sg = 00000000bfca0f98!!! >>>>>> [ 44.456000] __blk_segment_map_sg: length = 4096, nbytes = >>>>>> 4096, sum = 8192 > 65536 >>>>>> [ 44.456000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 44.456000] NEW SEGMENT sg = 00000000bfca0f98!!! >>>>>> [ 44.456000] __blk_segment_map_sg: length = 4096, nbytes = >>>>>> 4096, sum = 8192 > 65536 >>>>>> [ 44.456000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 44.456000] NEW SEGMENT sg = 00000000bfca0f98!!! >>>>>> [ 44.456000] __blk_segment_map_sg: length = 4096, nbytes = >>>>>> 4096, sum = 8192 > 65536 >>>>>> [ 44.456000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 44.456000] scsi_init_sgtable: count = 7, nents = 7 >>>>>> [ 44.456000] timer_interrupt(CPU 0): delayed! cycles >>>>>> 4527081F >>>>>> rem C6C21 next/now 14E153306E/14E146C44D >>>>>> [ 46.116000] scsi_init_sgtable: nr_phys_segments = 7 >>>>>> [ 46.116000] NEW SEGMENT sg = 00000000bfca0f98!!! >>>>>> [ 46.116000] __blk_segment_map_sg: length = 4096, nbytes = >>>>>> 4096, sum = 8192 > 65536 >>>>>> [ 46.116000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 46.116000] NEW SEGMENT sg = 00000000bfca0f98!!! >>>>>> [ 46.116000] __blk_segment_map_sg: length = 4096, nbytes = >>>>>> 4096, sum = 8192 > 65536 >>>>>> [ 46.116000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 46.116000] NEW SEGMENT sg = 00000000bfca0f98!!! >>>>>> [ 46.116000] __blk_segment_map_sg: length = 4096, nbytes = >>>>>> 4096, sum = 8192 > 65536 >>>>>> [ 46.116000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 46.116000] NEW SEGMENT sg = 00000000bfca0f98!!! >>>>>> [ 46.116000] __blk_segment_map_sg: length = 4096, nbytes = >>>>>> 4096, sum = 8192 > 65536 >>>>>> [ 46.116000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 46.116000] NEW SEGMENT sg = 00000000bfca0f98!!! >>>>>> [ 46.116000] __blk_segment_map_sg: length = 8192, nbytes = >>>>>> 4096, sum = 12288 > 65536 >>>>>> [ 46.116000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 46.116000] NEW SEGMENT sg = 00000000bfca0f98!!! >>>>>> [ 46.116000] __blk_segment_map_sg: length = 16384, nbytes = >>>>>> 4096, sum = 20480 > 65536 >>>>>> [ 46.116000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 46.116000] scsi_init_sgtable: count = 7, nents = 7 >>>>>> [ 46.116000] timer_interrupt(CPU 0): delayed! cycles >>>>>> 453F0A77 >>>>>> rem 223089 next/now 152BB6286E/152B93F7E5 >>>>>> [ 47.780000] scsi_init_sgtable: nr_phys_segments = 1 >>>>>> [ 47.780000] scsi_init_sgtable: count = 1, nents = 1 >>>>>> [ 47.896000] scsi_init_sgtable: nr_phys_segments = 6 >>>>>> [ 47.896000] NEW SEGMENT sg = 000000007fa911e8!!! >>>>>> [ 47.896000] __blk_segment_map_sg: length = 61440, nbytes = >>>>>> 4096, sum = 65536 > 65536 >>>>>> [ 47.896000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 47.896000] NEW SEGMENT sg = 000000007fa911e8!!! >>>>>> [ 47.896000] __blk_segment_map_sg: length = 4096, nbytes = >>>>>> 4096, sum = 8192 > 65536 >>>>>> [ 47.896000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 47.896000] NEW SEGMENT sg = 000000007fa911e8!!! >>>>>> [ 47.896000] __blk_segment_map_sg: length = 4096, nbytes = >>>>>> 4096, sum = 8192 > 65536 >>>>>> [ 47.896000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 47.896000] NEW SEGMENT sg = 000000007fa911e8!!! >>>>>> [ 47.896000] __blk_segment_map_sg: length = 8192, nbytes = >>>>>> 4096, sum = 12288 > 65536 >>>>>> [ 47.896000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 47.896000] NEW SEGMENT sg = 000000007fa911e8!!! >>>>>> [ 47.896000] __blk_segment_map_sg: length = 8192, nbytes = >>>>>> 4096, sum = 12288 > 65536 >>>>>> [ 47.896000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 47.896000] scsi_init_sgtable: count = 6, nents = 6 >>>>>> [ 47.896000] timer_interrupt(CPU 0): delayed! cycles >>>>>> 3AB087E2 >>>>>> rem 23E4DE next/now 1570BBD5EE/157097F110 >>>>>> [ 49.324000] scsi_init_sgtable: nr_phys_segments = 1 >>>>>> [ 49.324000] scsi_init_sgtable: count = 1, nents = 1 >>>>>> [ 49.440000] scsi_init_sgtable: nr_phys_segments = 2 >>>>>> [ 49.440000] NEW SEGMENT sg = 000000007fa911e8!!! >>>>>> [ 49.440000] __blk_segment_map_sg: length = 65536, nbytes = >>>>>> 4096, sum = 69632 > 65536 >>>>>> >>>>>> (this is interesting! Here we reach a sum of > 65536 the >>>>>> first >>>>>> time) >>>>>> >>>>>> [ 49.440000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 1, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 49.440000] NEW SEGMENT sg = 000000007fa911e8!!! >>>>>> [ 49.440000] __blk_segment_map_sg: length = 16384, nbytes = >>>>>> 4096, sum = 20480 > 65536 >>>>>> [ 49.440000] __blk_segment_map_sg: BIOVEC_PHYS_MERGEABLE = >>>>>> 0, >>>>>> BIOVEC_SEG_BOUNDARY = 1 >>>>>> [ 49.440000] *** FIXIT *** HELGE: nsegs > rq >>>>>> ->nr_phys_segments >>>>>> = 3 > 2 >>>>>> [ 49.440000] scsi_init_sgtable: count = 3, nents = 2 >>>>>> [ 50.116000] ------------[ cut here ]------------ >>>>>> [ 50.172000] WARNING: at /build/linux-4.4/linux >>>>>> -4.4.2/drivers/scsi/scsi_lib.c:1104 >>>>>> >>>>>> (this is usually a BUG(). I changed it to WARN() in the hope >>>>>> it >>>>>> would work anyway. It didn't.) >>>>>> >>>>>> [ 50.260000] Modules linked in: sd_mod sr_mod cdrom >>>>>> ata_generic >>>>>> ohci_pci ehci_pci ohci_hcd ehci_hcd pata_ns87415 sym53c8xx >>>>>> libata >>>>>> scsi_transport_spi scsi_mod usbcorep >>>>>> [ 50.456000] CPU: 0 PID: 70 Comm: systemd-udevd Not tainted >>>>>> 4.4.0-1-parisc64-smp #5 Debian 4.4.2-2 >>>>>> [ 50.564000] task: 000000007f948b28 ti: 000000007fa90000 >>>>>> task.ti: 000000007fa90000 >>>>>> [ 50.652000] >>>>>> [ 50.672000] YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI >>>>>> [ 50.728000] PSW: 00001000000001001111100100001110 Not >>>>>> tainted >>>>>> [ 50.796000] r00-03 000000ff0804f90e 00000000409ea2e0 >>>>>> 00000000003e2ee0 000000007fa91140 >>>>>> [ 50.892000] r04-07 00000000003cd000 000000007f914300 >>>>>> 000000007f914b10 0000000000000003 >>>>>> [ 50.988000] r08-11 0000000000000000 000000007f918000 >>>>>> 0000000040bdd6b0 00000000003cd800 >>>>>> [ 51.084000] r12-15 0000000000000000 000000007fa90778 >>>>>> 00000000003cd000 000000007f918000 >>>>>> [ 51.180000] r16-19 0000000000001300 0000000040bdd6b8 >>>>>> 0000000040bdd6bc 0000000040ba2420 >>>>>> [ 51.276000] r20-23 0000000099116e92 0000000000000000 >>>>>> 00000000000002a0 00000000000002ee >>>>>> [ 51.372000] r24-27 0000000000000000 000000000800000e >>>>>> 0000000040b60750 00000000409b3ae0 >>>>>> [ 51.468000] r28-31 0000000000000002 000000007fa914f0 >>>>>> 000000007fa911e0 0000000040ba2408 >>>>>> [ 51.564000] sr00-03 0000000000015000 0000000000000000 >>>>>> 0000000000000000 0000000000015000 >>>>>> [ 51.660000] sr04-07 0000000000000000 0000000000000000 >>>>>> 0000000000000000 0000000000000000 >>>>>> [ 51.756000] >>>>>> [ 51.772000] IASQ: 0000000000000000 0000000000000000 IAOQ: >>>>>> 00000000003e2f24 00000000003e2f28 >>>>>> [ 51.872000] IIR: 03ffe01f ISR: 0000000010340000 IOR: >>>>>> 000000fea4691528 >>>>>> [ 51.956000] CPU: 0 CR30: 000000007fa90000 CR31: >>>>>> 00000000ffff7dff >>>>>> [ 52.040000] ORIG_R28: 0000000040b60718 >>>>>> [ 52.084000] IAOQ[0]: scsi_init_sgtable+0xfc/0x1b8 >>>>>> [scsi_mod] >>>>>> [ 52.152000] IAOQ[1]: scsi_init_sgtable+0x100/0x1b8 >>>>>> [scsi_mod] >>>>>> [ 52.224000] RP(r2): scsi_init_sgtable+0xb8/0x1b8 >>>>>> [scsi_mod] >>>>>> [ 52.292000] Backtrace: >>>>>> [ 52.320000] [<00000000003e304c>] scsi_init_io+0x6c/0x258 >>>>>> [scsi_mod] >>>>>> [ 52.396000] [<000000000087d078>] >>>>>> sd_init_command+0x70/0xec8 >>>>>> [sd_mod] >>>>>> >>>>>> In general I think the bug is somehow in blk-merge.c. >>>>>> But I'm not an expert in that code. >>>>> >>>>> The warning was added in this patch sequence: >>>>> https://lkml.org/lkml/2015/11/23/996 >>>>> >>>>> Possibly, but above seems to indicate that it could be driver >>>>> issue >>>>> as well. >>>> >>>> >>>> I believe this bug was introduced by the following merge: >>>> >>>> commit 1081230b748de8f03f37f80c53dfa89feda9b8de >>>> Merge: df91039 2ca495a >>>> Author: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> >>>> Date: Wed Sep 2 13:10:25 2015 -0700 >>>> >>>> Merge branch 'for-4.3/core' of git://git.kernel.dk/linux-block >>>> >>>> Pull core block updates from Jens Axboe: >>>> "This first core part of the block IO changes contains: >>>> >>>> - Cleanup of the bio IO error signaling from Christoph. We >>>> used to >>>> rely on the uptodate bit and passing around of an error, >>>> now >>>> we >>>> store the error in the bio itself. >>>> >>>> - Improvement of the above from myself, by shrinking the >>>> bio >>>> size >>>> down again to fit in two cachelines on x86-64. >>>> >>>> - Revert of the max_hw_sectors cap removal from a revision >>>> again, >>>> from Jeff Moyer. This caused performance regressions in >>>> various >>>> tests. Reinstate the limit, bump it to a more reasonable >>>> size >>>> instead. >>>> >>>> - Make /sys/block/<dev>/queue/discard_max_bytes writeable, >>>> by >>>> me. >>>> Most devices have huge trim limits, which can cause nasty >>>> latencies >>>> when deleting files. Enable the admin to configure the >>>> size >>>> down. >>>> We will look into having a more sane default instead of >>>> UINT_MAX >>>> sectors. >>>> >>>> - Improvement of the SGP gaps logic from Keith Busch. >>>> >>>> - Enable the block core to handle arbitrarily sized bios, >>>> which >>>> enables a nice simplification of bio_add_page() (which is >>>> an >>>> IO hot >>>> path). From Kent. >>>> >>>> - Improvements to the partition io stats accounting, making >>>> it >>>> faster. From Ming Lei. >>>> >>>> - Also from Ming Lei, a basic fixup for overflow of the >>>> sysfs >>>> pending >>>> file in blk-mq, as well as a fix for a blk-mq timeout >>>> race >>>> condition. >>>> >>>> - Ming Lin has been carrying Kents above mentioned patches >>>> forward >>>> for a while, and testing them. Ming also did a few fixes >>>> around >>>> that. >>>> >>>> - Sasha Levin found and fixed a use-after-free problem >>>> introduced by >>>> the bio->bi_error changes from Christoph. >>>> >>>> - Small blk cgroup cleanup from Viresh Kumar" >>>> >>>> * 'for-4.3/core' of git://git.kernel.dk/linux-block: (26 >>>> commits) >>>> blk: Fix bio_io_vec index when checking bvec gaps >>>> block: Replace SG_GAPS with new queue limits mask >>>> block: bump BLK_DEF_MAX_SECTORS to 2560 >>>> Revert "block: remove artifical max_hw_sectors cap" >>>> blk-mq: fix race between timeout and freeing request >>>> blk-mq: fix buffer overflow when reading sysfs file of >>>> 'pending' >>>> Documentation: update notes in biovecs about arbitrarily >>>> sized >>>> bios >>>> block: remove bio_get_nr_vecs() >>>> fs: use helper bio_add_page() instead of open coding on >>>> bi_io_vec >>>> block: kill merge_bvec_fn() completely >>>> md/raid5: get rid of bio_fits_rdev() >>>> md/raid5: split bio for chunk_aligned_read >>>> block: remove split code in >>>> blkdev_issue_{discard,write_same} >>>> btrfs: remove bio splitting and merge_bvec_fn() calls >>>> bcache: remove driver private bio splitting code >>>> block: simplify bio_add_page() >>>> block: make generic_make_request handle arbitrarily sized >>>> bios >>>> blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL) >>>> block: don't access bio->bi_error after bio_put() >>>> block: shrink struct bio down to 2 cache lines again >>>> ... >>> >>> If you can bisect it down to the exact commit, I might be able to >>> work >>> out what's the problem. Otherwise, even in an all modular config, >>> I >>> can't reproduce this on 4.5-rc4, so it may be fixed upstream (just >>> not >>> backported). >> >> >> Okay, the bug was introduced by the following change: >> >> commit 54efd50bfd873e2dbf784e0b21a8027ba4299a3e >> Author: Kent Overstreet <kent.overstreet@xxxxxxxxx> > > If you've verified that reverting this alone gets you a bootable > kernel, it's time to report it to the appropriate lists, which would be > linux-block and linux-scsi. I verified that commit 54efd50bfd873e2dbf784e0b21a8027ba4299a3e in linux-block fails to boot and commit 41609892701e26724b8617201f43254cadf2e7ae (blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL)) does boot successfully. Commit 41609892701e26724b8617201f43254cadf2e7ae is previous commit in tree. I don't believe that the change can be reverted from Linus' tree as this commit allowed other stuff to be removed (see second paragraph of commit description). Dave -- John David Anglin dave.anglin@xxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
