| Message ID | 20241216162701.57549-5-willy@infradead.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [1/5] squashfs: Use a folio throughout squashfs_read_folio() | expand |
On 16/12/2024 16:26, Matthew Wilcox (Oracle) wrote: > squashfs_fill_page is only used in this file, so make it static. > Use kmap_local instead of kmap_atomic, and return a bool so that > the caller can use folio_end_read() which saves an atomic operation > over calling folio_mark_uptodate() followed by folio_unlock(). > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Hi Matthew, This patch causes 2 oops (VM_BUG_ON_FOLIO). The cause and fix for the first oops follows (second oops in the next email). > --- > fs/squashfs/file.c | 21 ++++++++++++--------- > fs/squashfs/squashfs.h | 1 - > 2 files changed, 12 insertions(+), 10 deletions(-) > > diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c > index 1f27e8161319..d363fb26c2c8 100644 > --- a/fs/squashfs/file.c > +++ b/fs/squashfs/file.c > @@ -362,19 +362,21 @@ static int read_blocklist(struct inode *inode, int index, u64 *block) > return squashfs_block_size(size); > } > > -void squashfs_fill_page(struct page *page, struct squashfs_cache_entry *buffer, int offset, int avail) > +static bool squashfs_fill_page(struct folio *folio, > + struct squashfs_cache_entry *buffer, size_t offset, > + size_t avail) > { > - int copied; > + size_t copied; > void *pageaddr; > > - pageaddr = kmap_atomic(page); > + pageaddr = kmap_local_folio(folio, 0); > copied = squashfs_copy_data(pageaddr, buffer, offset, avail); > memset(pageaddr + copied, 0, PAGE_SIZE - copied); > - kunmap_atomic(pageaddr); > + kunmap_local(pageaddr); > > - flush_dcache_page(page); > - if (copied == avail) > - SetPageUptodate(page); > + flush_dcache_folio(folio); > + > + return copied == avail; > } > > /* Copy data into page cache */ > @@ -398,6 +400,7 @@ void squashfs_copy_cache(struct folio *folio, > bytes -= PAGE_SIZE, offset += PAGE_SIZE) { > struct folio *push_folio; > size_t avail = buffer ? min(bytes, PAGE_SIZE) : 0; > + bool filled = false; > > TRACE("bytes %zu, i %d, available_bytes %zu\n", bytes, i, avail); > > @@ -412,9 +415,9 @@ void squashfs_copy_cache(struct folio *folio, > if (folio_test_uptodate(push_folio)) > goto skip_folio; > > - squashfs_fill_page(&push_folio->page, buffer, offset, avail); > + filled = squashfs_fill_page(push_folio, buffer, offset, avail); > skip_folio: > - folio_unlock(push_folio); > + folio_end_read(folio, filled); This should be folio_end_read(push_folio, filled) Without this folio_end_read() is repeatedly called on folio, generating the following oops [ 187.271288][ T8043] page: refcount:2 mapcount:0 mapping:ffff888116ae0798 index:0x100 pfn:0x1296c7 [ 187.272129][ T8043] memcg:ffff8881016cc000 [ 187.272458][ T8043] aops:squashfs_aops ino:1b dentry name(?):".tmp_vmlinux1" [ 187.273013][ T8043] flags: 0x4000000000000028(uptodate|lru|zone=2) [ 187.273500][ T8043] raw: 4000000000000028 ffffea0004655308 ffffea0004ac2e08 ffff888116ae0798 [ 187.274160][ T8043] raw: 0000000000000100 0000000000000000 00000002ffffffff ffff8881016cc000 [ 187.274809][ T8043] page dumped because: VM_BUG_ON_FOLIO(!folio_test_locked(folio)) [ 187.275348][ T8043] page_owner tracks the page as allocated [ 187.275787][ T8043] page last allocated via order 0, migratetype Movable, gfp_mask 0x152c4a(GFP_N0 [ 187.277262][ T8043] post_alloc_hook+0x2d0/0x350 [ 187.277586][ T8043] get_page_from_freelist+0xb39/0x22a0 [ 187.277941][ T8043] __alloc_pages_noprof+0x1bc/0x480 [ 187.278279][ T8043] __folio_alloc_noprof+0x11/0x90 [ 187.278600][ T8043] page_cache_ra_unbounded+0x2e3/0x750 [ 187.278939][ T8043] page_cache_ra_order+0x8ef/0xc30 [ 187.279252][ T8043] page_cache_async_ra+0x5cb/0x820 [ 187.279567][ T8043] filemap_get_pages+0x105b/0x1bd0 [ 187.279880][ T8043] filemap_read+0x3b6/0xd50 [ 187.280157][ T8043] generic_file_read_iter+0x344/0x450 [ 187.280481][ T8043] __kernel_read+0x3b5/0xb10 [ 187.280774][ T8043] integrity_kernel_read+0x7f/0xb0 [ 187.281091][ T8043] ima_calc_file_hash_tfm+0x2bc/0x3d0 [ 187.281425][ T8043] ima_calc_file_hash+0x1ba/0x490 [ 187.281756][ T8043] ima_collect_measurement+0x848/0x9d0 [ 187.282088][ T8043] process_measurement+0x126b/0x2390 [ 187.282409][ T8043] page last free pid 4949 tgid 4949 stack trace: [ 187.282788][ T8043] free_unref_folios+0x8ea/0x13e0 [ 187.283095][ T8043] folios_put_refs+0x589/0x7b0 [ 187.283386][ T8043] free_pages_and_swap_cache+0x23d/0x490 [ 187.283727][ T8043] __tlb_batch_free_encoded_pages+0xf9/0x290 [ 187.284115][ T8043] tlb_finish_mmu+0x168/0x7b0 [ 187.284438][ T8043] vms_clear_ptes.part.0+0x4b7/0x690 [ 187.284853][ T8043] vms_complete_munmap_vmas+0x6c3/0x9e0 [ 187.285276][ T8043] do_vmi_align_munmap+0x600/0x870 [ 187.285679][ T8043] __do_sys_brk+0x888/0xa50 [ 187.286001][ T8043] do_syscall_64+0x74/0x1c0 [ 187.286325][ T8043] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 187.286768][ T8043] ------------[ cut here ]------------ [ 187.287114][ T8043] kernel BUG at mm/filemap.c:1534! [ 187.287464][ T8043] Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI [ 187.287979][ T8043] CPU: 13 UID: 0 PID: 8043 Comm: wc Not tainted 6.13.0-rc2-00368-g673506e97177 5 [ 187.288717][ T8043] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.24 [ 187.289495][ T8043] RIP: 0010:folio_end_read+0x165/0x1a0 [ 187.289910][ T8043] Code: 89 ef 31 f6 e8 1c c6 ff ff 5b 5d 41 5c 41 5d 41 5e e9 1f 62 ca ff e8 1a0 [ 187.291452][ T8043] RSP: 0018:ffffc9000a0cea00 EFLAGS: 00010293 [ 187.291867][ T8043] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000a0ce8a8 [ 187.292442][ T8043] RDX: ffff888118375880 RSI: ffffffff81cd65a5 RDI: ffff888118375cc4 [ 187.293006][ T8043] RBP: ffffea0004a5b1c0 R08: 0000000000000000 R09: fffffbfff1efaefa [ 187.293632][ T8043] R10: ffffffff8f7d77d7 R11: 0000000000000001 R12: 0000000000000001 [ 187.294228][ T8043] R13: 0000000000000001 R14: 0000000000000101 R15: ffffea0004a5b1c0 [ 187.294808][ T8043] FS: 00007f2509ad0700(0000) GS:ffff888159480000(0000) knlGS:0000000000000000 [ 187.295485][ T8043] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 187.295993][ T8043] CR2: 00007fff92c60000 CR3: 0000000124c28000 CR4: 00000000003506f0 [ 187.296600][ T8043] Call Trace: [ 187.296837][ T8043] <TASK> [ 187.297052][ T8043] ? die+0x31/0x80 [ 187.297332][ T8043] ? do_trap+0x232/0x430 [ 187.297668][ T8043] ? folio_end_read+0x165/0x1a0 [ 187.298045][ T8043] ? folio_end_read+0x165/0x1a0 [ 187.298414][ T8043] ? do_error_trap+0xf4/0x230 [ 187.298741][ T8043] ? folio_end_read+0x165/0x1a0 [ 187.299130][ T8043] ? handle_invalid_op+0x34/0x40 [ 187.299442][ T8043] ? folio_end_read+0x165/0x1a0 [ 187.299748][ T8043] ? exc_invalid_op+0x2d/0x40 [ 187.300104][ T8043] ? asm_exc_invalid_op+0x1a/0x20 [ 187.300487][ T8043] ? folio_end_read+0x165/0x1a0 [ 187.300821][ T8043] ? folio_end_read+0x165/0x1a0 [ 187.301164][ T8043] squashfs_copy_cache+0x1d4/0x540 [ 187.301532][ T8043] squashfs_read_folio+0xa13/0xc00 [ 187.301869][ T8043] ? __pfx_squashfs_read_folio+0x10/0x10 [ 187.302219][ T8043] ? __pfx_squashfs_read_folio+0x10/0x10 [ 187.302566][ T8043] filemap_read_folio+0xc0/0x2a0 [ 187.302886][ T8043] ? __pfx_filemap_read_folio+0x10/0x10 [ 187.303257][ T8043] ? page_cache_async_ra+0x5cb/0x820 [ 187.303624][ T8043] filemap_get_pages+0x155c/0x1bd0 [ 187.303968][ T8043] ? __pfx_make_vfsgid+0x10/0x10 [ 187.304279][ T8043] ? __pfx_filemap_get_pages+0x10/0x10 [ 187.304626][ T8043] filemap_read+0x3b6/0xd50 [ 187.304944][ T8043] ? __pfx_filemap_read+0x10/0x10 [ 187.305280][ T8043] ? kernel_text_address+0x8d/0x100 [ 187.305643][ T8043] ? pvh_start_xen+0x1/0x108 [ 187.305964][ T8043] ? __kernel_text_address+0xd/0x40 [ 187.306309][ T8043] ? unwind_get_return_address+0x59/0xa0 [ 187.306697][ T8043] ? __pfx_stack_trace_consume_entry+0x10/0x10 [ 187.307104][ T8043] ? arch_stack_walk+0x9d/0xf0 [ 187.307413][ T8043] ? stack_trace_save+0x95/0xd0 [ 187.307737][ T8043] ? __pfx_stack_trace_save+0x10/0x10 [ 187.308133][ T8043] ? stack_depot_save_flags+0x28/0x9d0 [ 187.308652][ T8043] generic_file_read_iter+0x344/0x450 [ 187.309054][ T8043] __kernel_read+0x3b5/0xb10 [ 187.309430][ T8043] ? __pfx___kernel_read+0x10/0x10 [ 187.309855][ T8043] integrity_kernel_read+0x7f/0xb0 [ 187.310279][ T8043] ? __pfx_integrity_kernel_read+0x10/0x10 [ 187.310737][ T8043] ? _sha256_update+0x93/0x220 [ 187.311140][ T8043] ? __pfx_sha256_transform_rorx+0x10/0x10 [ 187.311579][ T8043] ? kasan_save_track+0x14/0x30 [ 187.311956][ T8043] ima_calc_file_hash_tfm+0x2bc/0x3d0 [ 187.312362][ T8043] ? __pfx_ima_calc_file_hash_tfm+0x10/0x10 [ 187.312780][ T8043] ? squashfs_xattr_handler_get+0x522/0x6c0 [ 187.313171][ T8043] ? vfs_getxattr_alloc+0x1b9/0x340 [ 187.313541][ T8043] ? ima_read_xattr+0x38/0x60 [ 187.313868][ T8043] ? process_measurement+0x11e2/0x2390 [ 187.314237][ T8043] ? ima_file_check+0xb4/0x100 [ 187.314556][ T8043] ? security_file_post_open+0x8e/0x210 [ 187.314933][ T8043] ? path_openat+0x13f9/0x2d50 [ 187.315261][ T8043] ? mark_lock+0x101/0x1780 [ 187.315558][ T8043] ? entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 187.315949][ T8043] ? mark_held_locks+0x9f/0xe0 [ 187.316266][ T8043] ? __pfx_mark_lock+0x10/0x10 [ 187.316590][ T8043] ? lockdep_hardirqs_on+0x7c/0x100 [ 187.317283][ T8043] ? _raw_spin_unlock_irqrestore+0x3b/0x80 [ 187.317722][ T8043] ? debug_check_no_obj_freed+0x2eb/0x5c0 [ 187.318090][ T8043] ? make_vfsgid+0xf2/0x140 [ 187.318389][ T8043] ? __pfx_make_vfsgid+0x10/0x10 [ 187.318719][ T8043] ? __pfx_debug_check_no_obj_freed+0x10/0x10 [ 187.319113][ T8043] ? ima_alloc_tfm+0x21d/0x2d0 [ 187.319430][ T8043] ? generic_fillattr+0x6bf/0x940 [ 187.319762][ T8043] ima_calc_file_hash+0x1ba/0x490 [ 187.320096][ T8043] ima_collect_measurement+0x848/0x9d0 [ 187.320459][ T8043] ? __pfx_ima_collect_measurement+0x10/0x10 [ 187.320855][ T8043] ? squashfs_xattr_handler_get+0x527/0x6c0 [ 187.321253][ T8043] ? process_measurement+0x86d/0x2390 [ 187.321630][ T8043] ? find_held_lock+0x2d/0x110 [ 187.321973][ T8043] ? xattr_resolve_name+0x27b/0x3f0 [ 187.322333][ T8043] ? __pfx_squashfs_xattr_handler_get+0x10/0x10 [ 187.322762][ T8043] ? vfs_getxattr_alloc+0xf1/0x340 [ 187.323118][ T8043] ? ima_get_hash_algo+0x27d/0x410 [ 187.323474][ T8043] ? __pfx_ima_get_hash_algo+0x10/0x10 [ 187.323895][ T8043] ? process_measurement+0x126b/0x2390 [ 187.324268][ T8043] process_measurement+0x126b/0x2390 [ 187.324661][ T8043] ? __pfx_process_measurement+0x10/0x10 [ 187.325046][ T8043] ? tomoyo_check_open_permission+0x1f0/0x3a0 [ 187.325463][ T8043] ? __pfx_smack_log+0x10/0x10 [ 187.325796][ T8043] ? smk_access+0x39a/0x5e0 [ 187.326105][ T8043] ? smk_tskacc+0x340/0x430 [ 187.326409][ T8043] ? smack_file_open+0x1c1/0x250 [ 187.326741][ T8043] ? __pfx_smack_file_open+0x10/0x10 [ 187.327087][ T8043] ? inode_to_bdi+0x9e/0x160 [ 187.327389][ T8043] ima_file_check+0xb4/0x100 [ 187.327687][ T8043] ? __pfx_ima_file_check+0x10/0x10 [ 187.328056][ T8043] security_file_post_open+0x8e/0x210 [ 187.328427][ T8043] path_openat+0x13f9/0x2d50 [ 187.328740][ T8043] ? __pfx_path_openat+0x10/0x10 [ 187.329057][ T8043] ? __pfx___lock_acquire+0x10/0x10 [ 187.329402][ T8043] ? lock_acquire+0x1b1/0x550 [ 187.329732][ T8043] ? find_held_lock+0x2d/0x110 [ 187.330052][ T8043] do_filp_open+0x1f8/0x460 [ 187.330343][ T8043] ? __pfx_do_filp_open+0x10/0x10 [ 187.330666][ T8043] ? find_held_lock+0x2d/0x110 [ 187.330979][ T8043] ? do_raw_spin_lock+0x12d/0x2b0 [ 187.331318][ T8043] ? __pfx_do_raw_spin_lock+0x10/0x10 [ 187.331661][ T8043] ? __phys_addr_symbol+0x30/0x70 [ 187.331999][ T8043] ? __check_object_size+0x4f7/0x7d0 [ 187.332349][ T8043] ? _raw_spin_unlock+0x28/0x50 [ 187.332662][ T8043] ? alloc_fd+0x41f/0x760 [ 187.332963][ T8043] do_sys_openat2+0x160/0x1c0 [ 187.333296][ T8043] ? __pfx_do_sys_openat2+0x10/0x10 [ 187.333655][ T8043] ? kmem_cache_free+0x39e/0x5b0 [ 187.333979][ T8043] ? security_file_free+0xb9/0x180 [ 187.334304][ T8043] ? __fput+0x686/0xb60 [ 187.334561][ T8043] __x64_sys_open+0x154/0x1e0 [ 187.334855][ T8043] ? __pfx___x64_sys_open+0x10/0x10 [ 187.335209][ T8043] do_syscall_64+0x74/0x1c0 [ 187.335503][ T8043] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 187.335882][ T8043] RIP: 0033:0x7f25094db960 [ 187.336176][ T8043] Code: 48 8b 15 2b 95 2c 00 f7 d8 64 89 02 48 83 c8 ff c3 66 0f 1f 84 00 00 004 [ 187.337420][ T8043] RSP: 002b:00007fff92c63888 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 187.337967][ T8043] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f25094db960 [ 187.338505][ T8043] RDX: 00007f2509a74e50 RSI: 0000000000000000 RDI: 00007fff92c6a173 [ 187.339015][ T8043] RBP: 00007fff92c6a173 R08: 6f2e736d79736c6c R09: 00007f250944b99a [ 187.339511][ T8043] R10: 00007f25097a46a0 R11: 0000000000000246 R12: 00007f2509a74e50 [ 187.340044][ T8043] R13: 0000000000000993 R14: 0000000000000001 R15: 00007fff92c6a173 [ 187.340523][ T8043] </TASK> [ 187.340707][ T8043] Modules linked in: [ 187.340976][ T8043] ---[ end trace 0000000000000000 ]--- [ 187.341417][ T8043] RIP: 0010:folio_end_read+0x165/0x1a0 [ 187.341807][ T8043] Code: 89 ef 31 f6 e8 1c c6 ff ff 5b 5d 41 5c 41 5d 41 5e e9 1f 62 ca ff e8 1a0 [ 187.343080][ T8043] RSP: 0018:ffffc9000a0cea00 EFLAGS: 00010293 [ 187.343461][ T8043] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000a0ce8a8 [ 187.343989][ T8043] RDX: ffff888118375880 RSI: ffffffff81cd65a5 RDI: ffff888118375cc4 [ 187.344527][ T8043] RBP: ffffea0004a5b1c0 R08: 0000000000000000 R09: fffffbfff1efaefa [ 187.345049][ T8043] R10: ffffffff8f7d77d7 R11: 0000000000000001 R12: 0000000000000001 [ 187.345598][ T8043] R13: 0000000000000001 R14: 0000000000000101 R15: ffffea0004a5b1c0 [ 187.346144][ T8043] FS: 00007f2509ad0700(0000) GS:ffff888159480000(0000) knlGS:0000000000000000 [ 187.346802][ T8043] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 187.347288][ T8043] CR2: 00007fff92c60000 CR3: 0000000124c28000 CR4: 00000000003506f0 [ 187.347888][ T8043] Kernel panic - not syncing: Fatal exception [ 187.348594][ T8043] Kernel Offset: disabled [ 187.348906][ T8043] Rebooting in 86400 seconds..
On 16/12/2024 16:26, Matthew Wilcox (Oracle) wrote: > squashfs_fill_page is only used in this file, so make it static. > Use kmap_local instead of kmap_atomic, and return a bool so that > the caller can use folio_end_read() which saves an atomic operation > over calling folio_mark_uptodate() followed by folio_unlock(). > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Hi Matthew, Once the first oops is fixed, a second oops (VM_BUG_ON_FOLIO) will occasionally occur. The cause and oops follows: > --- > fs/squashfs/file.c | 21 ++++++++++++--------- > fs/squashfs/squashfs.h | 1 - > 2 files changed, 12 insertions(+), 10 deletions(-) > > diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c > index 1f27e8161319..d363fb26c2c8 100644 > --- a/fs/squashfs/file.c > +++ b/fs/squashfs/file.c > @@ -362,19 +362,21 @@ static int read_blocklist(struct inode *inode, int index, u64 *block) > return squashfs_block_size(size); > } > > -void squashfs_fill_page(struct page *page, struct squashfs_cache_entry *buffer, int offset, int avail) > +static bool squashfs_fill_page(struct folio *folio, > + struct squashfs_cache_entry *buffer, size_t offset, > + size_t avail) > { > - int copied; > + size_t copied; > void *pageaddr; > > - pageaddr = kmap_atomic(page); > + pageaddr = kmap_local_folio(folio, 0); > copied = squashfs_copy_data(pageaddr, buffer, offset, avail); > memset(pageaddr + copied, 0, PAGE_SIZE - copied); > - kunmap_atomic(pageaddr); > + kunmap_local(pageaddr); > > - flush_dcache_page(page); > - if (copied == avail) > - SetPageUptodate(page); > + flush_dcache_folio(folio); > + > + return copied == avail; > } > > /* Copy data into page cache */ > @@ -398,6 +400,7 @@ void squashfs_copy_cache(struct folio *folio, > bytes -= PAGE_SIZE, offset += PAGE_SIZE) { > struct folio *push_folio; > size_t avail = buffer ? min(bytes, PAGE_SIZE) : 0; > + bool filled = false; > > TRACE("bytes %zu, i %d, available_bytes %zu\n", bytes, i, avail); > > @@ -412,9 +415,9 @@ void squashfs_copy_cache(struct folio *folio, > if (folio_test_uptodate(push_folio)) > goto skip_folio; If the folio is uptodate the code jumps to skip_folio, where folio_end_read() is called > > - squashfs_fill_page(&push_folio->page, buffer, offset, avail); > + filled = squashfs_fill_page(push_folio, buffer, offset, avail); > skip_folio: > - folio_unlock(push_folio); > + folio_end_read(push_folio, filled); This triggers the following oops [ 446.179884][ T7451] page: refcount:2 mapcount:0 mapping:ffff888000841218 ind8 [ 446.180418][ T7451] memcg:ffff8880162c4000 [ 446.180648][ T7451] aops:squashfs_aops ino:1f dentry name(?):".tmp_vmlinux2" [ 446.181006][ T7451] flags: 0x200000000000012d(locked|referenced|uptodate|lru) [ 446.181420][ T7451] raw: 200000000000012d ffffea0000afebc8 ffffea0000a870c8 8 [ 446.181839][ T7451] raw: 0000000000000101 0000000000000000 00000002ffffffff 0 [ 446.182261][ T7451] page dumped because: VM_BUG_ON_FOLIO(folio_test_uptodate) [ 446.182639][ T7451] page_owner tracks the page as allocated [ 446.182943][ T7451] page last allocated via order 0, migratetype Movable, gf6 [ 446.183886][ T7451] post_alloc_hook+0x2d0/0x350 [ 446.184126][ T7451] get_page_from_freelist+0xb39/0x22a0 [ 446.184395][ T7451] __alloc_pages_noprof+0x1bc/0x480 [ 446.184651][ T7451] __folio_alloc_noprof+0x11/0x90 [ 446.184898][ T7451] __filemap_get_folio+0x55a/0xb00 [ 446.185150][ T7451] squashfs_copy_cache+0x35d/0x540 [ 446.185402][ T7451] squashfs_read_folio+0xa13/0xc00 [ 446.185695][ T7451] filemap_read_folio+0xc0/0x2a0 [ 446.185941][ T7451] filemap_get_pages+0x155c/0x1bd0 [ 446.186195][ T7451] filemap_read+0x3b6/0xd50 [ 446.186428][ T7451] generic_file_read_iter+0x344/0x450 [ 446.186690][ T7451] __kernel_read+0x3b5/0xb10 [ 446.186928][ T7451] integrity_kernel_read+0x7f/0xb0 [ 446.187328][ T7451] ima_calc_file_hash_tfm+0x2bc/0x3d0 [ 446.187716][ T7451] ima_calc_file_hash+0x1ba/0x490 [ 446.188078][ T7451] ima_collect_measurement+0x848/0x9d0 [ 446.188364][ T7451] page last free pid 7451 tgid 7451 stack trace: [ 446.188711][ T7451] free_unref_folios+0x8ea/0x13e0 [ 446.189002][ T7451] shrink_folio_list+0xcff/0x4070 [ 446.189295][ T7451] shrink_lruvec+0xe94/0x29f0 [ 446.189586][ T7451] shrink_node+0xa74/0x2730 [ 446.189823][ T7451] do_try_to_free_pages+0x363/0x1860 [ 446.190101][ T7451] try_to_free_pages+0x2bf/0x790 [ 446.190428][ T7451] __alloc_pages_slowpath.constprop.0+0x7bc/0x2650 [ 446.190810][ T7451] __alloc_pages_noprof+0x3e6/0x480 [ 446.191134][ T7451] squashfs_bio_read+0x4af/0xf50 [ 446.191408][ T7451] squashfs_read_data+0x208/0xf10 [ 446.191723][ T7451] squashfs_readahead+0x1502/0x21e0 [ 446.192034][ T7451] read_pages+0x19f/0xdb0 [ 446.192298][ T7451] page_cache_ra_unbounded+0x3e0/0x750 [ 446.192646][ T7451] page_cache_ra_order+0x8ef/0xc30 [ 446.192958][ T7451] page_cache_async_ra+0x5cb/0x820 [ 446.193269][ T7451] filemap_get_pages+0x105b/0x1bd0 [ 446.193563][ T7451] ------------[ cut here ]------------ [ 446.193848][ T7451] kernel BUG at mm/filemap.c:1535! [ 446.194121][ T7451] Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI [ 446.194503][ T7451] CPU: 4 UID: 0 PID: 7451 Comm: cat Not tainted 6.13.0-rc20 [ 446.195006][ T7451] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS4 [ 446.195523][ T7451] RIP: 0010:folio_end_read+0x17b/0x1a0 [ 446.195812][ T7451] Code: e8 1a 62 ca ff 48 c7 c6 a0 17 d8 8a 48 89 ef e8 2b8 [ 446.196797][ T7451] RSP: 0018:ffffc900002e7710 EFLAGS: 00010293 [ 446.197114][ T7451] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffc908 [ 446.197522][ T7451] RDX: ffff88801befd880 RSI: ffffffff81cd65bb RDI: ffff8884 [ 446.197930][ T7451] RBP: ffffea0000a93200 R08: 0000000000000000 R09: fffffbfa [ 446.198353][ T7451] R10: ffffffff8f7d79d7 R11: 0000000000000001 R12: 00000000 [ 446.198765][ T7451] R13: 0000000000000000 R14: 0000000000000001 R15: ffffea00 [ 446.199174][ T7451] FS: 00007f92f7c65700(0000) GS:ffff88802da00000(0000) kn0 [ 446.199633][ T7451] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 446.199975][ T7451] CR2: 00007ff2432219d8 CR3: 0000000011268000 CR4: 00000000 [ 446.200385][ T7451] Call Trace: [ 446.200559][ T7451] <TASK> [ 446.200715][ T7451] ? die+0x31/0x80 [ 446.200918][ T7451] ? do_trap+0x232/0x430 [ 446.201142][ T7451] ? folio_end_read+0x17b/0x1a0 [ 446.201401][ T7451] ? folio_end_read+0x17b/0x1a0 [ 446.201658][ T7451] ? do_error_trap+0xf4/0x230 [ 446.201905][ T7451] ? folio_end_read+0x17b/0x1a0 [ 446.202167][ T7451] ? handle_invalid_op+0x34/0x40 [ 446.202434][ T7451] ? folio_end_read+0x17b/0x1a0 [ 446.202694][ T7451] ? exc_invalid_op+0x2d/0x40 [ 446.202947][ T7451] ? asm_exc_invalid_op+0x1a/0x20 [ 446.203216][ T7451] ? folio_end_read+0x17b/0x1a0 [ 446.203475][ T7451] ? folio_end_read+0x17b/0x1a0 [ 446.203735][ T7451] squashfs_copy_cache+0x1d4/0x540 [ 446.204005][ T7451] squashfs_read_folio+0xa13/0xc00 [ 446.204274][ T7451] ? __pfx_squashfs_read_folio+0x10/0x10 [ 446.204571][ T7451] ? __pfx_squashfs_read_folio+0x10/0x10 [ 446.204867][ T7451] filemap_read_folio+0xc0/0x2a0 [ 446.205128][ T7451] ? __pfx_filemap_read_folio+0x10/0x10 [ 446.205419][ T7451] ? page_cache_async_ra+0x5cb/0x820 [ 446.205703][ T7451] filemap_get_pages+0x155c/0x1bd0 [ 446.205972][ T7451] ? current_time+0x79/0x380 [ 446.206219][ T7451] ? __pfx_filemap_get_pages+0x10/0x10 [ 446.206520][ T7451] filemap_read+0x3b6/0xd50 [ 446.206771][ T7451] ? find_held_lock+0x2d/0x110 [ 446.207032][ T7451] ? vfs_write+0x57e/0x1190 [ 446.207279][ T7451] ? __pfx_filemap_read+0x10/0x10 [ 446.207554][ T7451] ? pipe_write+0xf9f/0x1ae0 [ 446.207828][ T7451] ? __pfx_pipe_write+0x10/0x10 [ 446.208135][ T7451] ? lock_acquire+0x1b1/0x550 [ 446.208435][ T7451] ? __pfx_autoremove_wake_function+0x10/0x10 [ 446.208810][ T7451] generic_file_read_iter+0x344/0x450 [ 446.209151][ T7451] ? rw_verify_area+0xd0/0x700 [ 446.209440][ T7451] vfs_read+0x83e/0xba0 [ 446.209672][ T7451] ? __pfx_vfs_read+0x10/0x10 [ 446.209920][ T7451] ? __pfx_generic_fadvise+0x10/0x10 [ 446.210203][ T7451] ksys_read+0x122/0x240 [ 446.210435][ T7451] ? __pfx_ksys_read+0x10/0x10 [ 446.210691][ T7451] do_syscall_64+0x74/0x1c0 [ 446.210932][ T7451] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 446.211243][ T7451] RIP: 0033:0x7f92f76dbba0 [ 446.211480][ T7451] Code: 0b 31 c0 48 83 c4 08 e9 be fe ff ff 48 8d 3d 3f f04 [ 446.212458][ T7451] RSP: 002b:00007fff1ae88768 EFLAGS: 00000246 ORIG_RAX: 000 [ 446.212887][ T7451] RAX: ffffffffffffffda RBX: 0000000000008000 RCX: 00007f90 [ 446.213292][ T7451] RDX: 0000000000008000 RSI: 000000003e0a0000 RDI: 00000003 [ 446.213700][ T7451] RBP: 0000000000008000 R08: 0000000000000003 R09: 00007f90 [ 446.214107][ T7451] R10: 0000000000000002 R11: 0000000000000246 R12: 00000000 [ 446.214518][ T7451] R13: 0000000000000003 R14: 0000000000000000 R15: 00000000 [ 446.214925][ T7451] </TASK> [ 446.215086][ T7451] Modules linked in: [ 446.215317][ T7451] ---[ end trace 0000000000000000 ]--- [ 446.215609][ T7451] RIP: 0010:folio_end_read+0x17b/0x1a0 [ 446.215906][ T7451] Code: e8 1a 62 ca ff 48 c7 c6 a0 17 d8 8a 48 89 ef e8 2b8 [ 446.216889][ T7451] RSP: 0018:ffffc900002e7710 EFLAGS: 00010293 [ 446.217204][ T7451] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffc908 [ 446.217609][ T7451] RDX: ffff88801befd880 RSI: ffffffff81cd65bb RDI: ffff8884 [ 446.218015][ T7451] RBP: ffffea0000a93200 R08: 0000000000000000 R09: fffffbfa [ 446.218459][ T7451] R10: ffffffff8f7d79d7 R11: 0000000000000001 R12: 00000000 [ 446.218878][ T7451] R13: 0000000000000000 R14: 0000000000000001 R15: ffffea00 [ 446.219287][ T7451] FS: 00007f92f7c65700(0000) GS:ffff88802da00000(0000) kn0 [ 446.219746][ T7451] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 446.220089][ T7451] CR2: 00007ff2432219d8 CR3: 0000000011268000 CR4: 00000000 [ 446.220498][ T7451] Kernel panic - not syncing: Fatal exception [ 446.221221][ T7451] Kernel Offset: disabled [ 446.221468][ T7451] Rebooting in 86400 seconds..
On Fri, Dec 20, 2024 at 06:19:35PM +0000, Phillip Lougher wrote: > > @@ -398,6 +400,7 @@ void squashfs_copy_cache(struct folio *folio, > > bytes -= PAGE_SIZE, offset += PAGE_SIZE) { > > struct folio *push_folio; > > size_t avail = buffer ? min(bytes, PAGE_SIZE) : 0; > > + bool filled = false; ahh, this should have been filled = true (if the folio is already uptodate, then it has been filled). Or maybe it'd be less confusing if we named the bool 'uptodate'. Would you like me to submit a fresh set of patches, or will you fix these two bugs up? Thanks for testing!
On 20/12/2024 18:24, Matthew Wilcox wrote: > On Fri, Dec 20, 2024 at 06:19:35PM +0000, Phillip Lougher wrote: >>> @@ -398,6 +400,7 @@ void squashfs_copy_cache(struct folio *folio, >>> bytes -= PAGE_SIZE, offset += PAGE_SIZE) { >>> struct folio *push_folio; >>> size_t avail = buffer ? min(bytes, PAGE_SIZE) : 0; >>> + bool filled = false; > > ahh, this should have been filled = true (if the folio is already > uptodate, then it has been filled). Or maybe it'd be less confusing if > we named the bool 'uptodate'. > > Would you like me to submit a fresh set of patches, or will you fix > these two bugs up? > > Thanks for testing! Np. Andrew Morton is kindly handling Squashfs patch submission to Linus for me, and so I can't easily fix them up. Andrew what you like done here please? Thanks Phillip
On Fri, 20 Dec 2024 18:42:57 +0000 Phillip Lougher <phillip@squashfs.org.uk> wrote: > > > On 20/12/2024 18:24, Matthew Wilcox wrote: > > On Fri, Dec 20, 2024 at 06:19:35PM +0000, Phillip Lougher wrote: > >>> @@ -398,6 +400,7 @@ void squashfs_copy_cache(struct folio *folio, > >>> bytes -= PAGE_SIZE, offset += PAGE_SIZE) { > >>> struct folio *push_folio; > >>> size_t avail = buffer ? min(bytes, PAGE_SIZE) : 0; > >>> + bool filled = false; > > > > ahh, this should have been filled = true (if the folio is already > > uptodate, then it has been filled). Or maybe it'd be less confusing if > > we named the bool 'uptodate'. > > > > Would you like me to submit a fresh set of patches, or will you fix > > these two bugs up? > > > > Thanks for testing! > > Np. > > Andrew Morton is kindly handling Squashfs patch submission to Linus for me, > and so I can't easily fix them up. > > Andrew what you like done here please? I think a v2 series would be best, please.
diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c index 1f27e8161319..d363fb26c2c8 100644 --- a/fs/squashfs/file.c +++ b/fs/squashfs/file.c @@ -362,19 +362,21 @@ static int read_blocklist(struct inode *inode, int index, u64 *block) return squashfs_block_size(size); } -void squashfs_fill_page(struct page *page, struct squashfs_cache_entry *buffer, int offset, int avail) +static bool squashfs_fill_page(struct folio *folio, + struct squashfs_cache_entry *buffer, size_t offset, + size_t avail) { - int copied; + size_t copied; void *pageaddr; - pageaddr = kmap_atomic(page); + pageaddr = kmap_local_folio(folio, 0); copied = squashfs_copy_data(pageaddr, buffer, offset, avail); memset(pageaddr + copied, 0, PAGE_SIZE - copied); - kunmap_atomic(pageaddr); + kunmap_local(pageaddr); - flush_dcache_page(page); - if (copied == avail) - SetPageUptodate(page); + flush_dcache_folio(folio); + + return copied == avail; } /* Copy data into page cache */ @@ -398,6 +400,7 @@ void squashfs_copy_cache(struct folio *folio, bytes -= PAGE_SIZE, offset += PAGE_SIZE) { struct folio *push_folio; size_t avail = buffer ? min(bytes, PAGE_SIZE) : 0; + bool filled = false; TRACE("bytes %zu, i %d, available_bytes %zu\n", bytes, i, avail); @@ -412,9 +415,9 @@ void squashfs_copy_cache(struct folio *folio, if (folio_test_uptodate(push_folio)) goto skip_folio; - squashfs_fill_page(&push_folio->page, buffer, offset, avail); + filled = squashfs_fill_page(push_folio, buffer, offset, avail); skip_folio: - folio_unlock(push_folio); + folio_end_read(folio, filled); if (i != folio->index) folio_put(push_folio); } diff --git a/fs/squashfs/squashfs.h b/fs/squashfs/squashfs.h index 9295556ecfd0..37f3518a804a 100644 --- a/fs/squashfs/squashfs.h +++ b/fs/squashfs/squashfs.h @@ -67,7 +67,6 @@ extern __le64 *squashfs_read_fragment_index_table(struct super_block *, u64, u64, unsigned int); /* file.c */ -void squashfs_fill_page(struct page *, struct squashfs_cache_entry *, int, int); void squashfs_copy_cache(struct folio *, struct squashfs_cache_entry *, size_t bytes, size_t offset);
squashfs_fill_page is only used in this file, so make it static. Use kmap_local instead of kmap_atomic, and return a bool so that the caller can use folio_end_read() which saves an atomic operation over calling folio_mark_uptodate() followed by folio_unlock(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- fs/squashfs/file.c | 21 ++++++++++++--------- fs/squashfs/squashfs.h | 1 - 2 files changed, 12 insertions(+), 10 deletions(-)