On 12/20/24 22:46, 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@xxxxxxxxxxxxx>
---
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..da25d6fa45ce 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 uptodate = true;
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);
+ uptodate = squashfs_fill_page(push_folio, buffer, offset, avail);
skip_folio:
- folio_unlock(push_folio);
+ folio_end_read(push_folio, uptodate);
Hi Matthew,
I'm still getting an oops with this (V2) patch. The same as before, which is an
assert in folio_end_read() triggers.
Looking at the code in folio_end_read(), the assert appears to happen irrespective
of the value of success.
void folio_end_read(struct folio *folio, bool success)
{
unsigned long mask = 1 << PG_locked;
/* Must be in bottom byte for x86 to work */
BUILD_BUG_ON(PG_uptodate > 7);
VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
VM_BUG_ON_FOLIO(folio_test_uptodate(folio), folio);
if (likely(success))
mask |= 1 << PG_uptodate;
if (folio_xor_flags_has_waiters(folio, mask))
folio_wake_bit(folio, PG_locked);
}
EXPORT_SYMBOL(folio_end_read);
Thanks
Phillip
The oops is
[ 977.270664][ T7696] page: refcount:2 mapcount:0 mapping:ffff8880114c1c98 index:0x100 pfn:0x2022c
[ 977.271277][ T7696] memcg:ffff8880162c4000
[ 977.271501][ T7696] aops:squashfs_aops ino:1f dentry name(?):".tmp_vmlinux2"
[ 977.271941][ T7696] flags: 0x200000000000012d(locked|referenced|uptodate|lru|active|zone=1)
[ 977.272375][ T7696] raw: 200000000000012d ffffea0000aeaf08 ffffea00009ae388 ffff8880114c1c98
[ 977.272796][ T7696] raw: 0000000000000100 0000000000000000 00000002ffffffff ffff8880162c4000
[ 977.273215][ T7696] page dumped because: VM_BUG_ON_FOLIO(folio_test_uptodate(folio))
[ 977.273600][ T7696] page_owner tracks the page as allocated
[ 977.273916][ T7696] page last allocated via order 0, migratetype Movable, gfp_mask 0x152c4a(GFP_NOFS|__GFP_HIGH0
[ 977.274987][ T7696] post_alloc_hook+0x2d0/0x350
[ 977.275233][ T7696] get_page_from_freelist+0xb39/0x22a0
[ 977.275512][ T7696] __alloc_pages_slowpath.constprop.0+0x2ff/0x2650
[ 977.275872][ T7696] __alloc_pages_noprof+0x3e6/0x480
[ 977.276139][ T7696] __folio_alloc_noprof+0x11/0x90
[ 977.276392][ T7696] page_cache_ra_unbounded+0x2e3/0x750
[ 977.276779][ T7696] page_cache_ra_order+0x8ef/0xc30
[ 977.277057][ T7696] page_cache_async_ra+0x5cb/0x820
[ 977.277530][ T7696] filemap_get_pages+0x105b/0x1bd0
[ 977.277827][ T7696] filemap_read+0x3b6/0xd50
[ 977.278058][ T7696] generic_file_read_iter+0x344/0x450
[ 977.278323][ T7696] __kernel_read+0x3b5/0xb10
[ 977.278581][ T7696] integrity_kernel_read+0x7f/0xb0
[ 977.278844][ T7696] ima_calc_file_hash_tfm+0x2bc/0x3d0
[ 977.279131][ T7696] ima_calc_file_hash+0x1ba/0x490
[ 977.279415][ T7696] ima_collect_measurement+0x848/0x9d0
[ 977.279721][ T7696] page last free pid 7695 tgid 7695 stack trace:
[ 977.280101][ T7696] free_unref_page+0x619/0x10e0
[ 977.280363][ T7696] __folio_put+0x31d/0x440
[ 977.280603][ T7696] put_page+0x21d/0x280
[ 977.280875][ T7696] anon_pipe_buf_release+0x11a/0x240
[ 977.281171][ T7696] pipe_read+0x635/0x13b0
[ 977.281447][ T7696] vfs_read+0xa0c/0xba0
[ 977.281761][ T7696] ksys_read+0x1fe/0x240
[ 977.282045][ T7696] do_syscall_64+0x74/0x1c0
[ 977.282314][ T7696] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 977.282679][ T7696] ------------[ cut here ]------------
[ 977.283000][ T7696] kernel BUG at mm/filemap.c:1535!
[ 977.283313][ T7696] Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
[ 977.283939][ T7696] CPU: 4 UID: 0 PID: 7696 Comm: cat Not tainted 6.13.0-rc2-00367-gbfe147475f84 #24
[ 977.284605][ T7696] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[ 977.285195][ T7696] RIP: 0010:folio_end_read+0x17b/0x1a0
[ 977.285517][ T7696] Code: e8 1a 62 ca ff 48 c7 c6 60 17 d8 8a 48 89 ef e8 2b d2 0e 00 0f 0b e8 04 62 ca ff 48 c8
[ 977.287017][ T7696] RSP: 0018:ffffc90007aa7710 EFLAGS: 00010293
[ 977.287424][ T7696] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffc90007aa75b8
[ 977.287897][ T7696] RDX: ffff888026320000 RSI: ffffffff81cd65bb RDI: ffff888026320444
[ 977.288356][ T7696] RBP: ffffea0000808b00 R08: 0000000000000000 R09: fffffbfff1efaf3a
[ 977.288781][ T7696] R10: ffffffff8f7d79d7 R11: 0000000000000001 R12: 0000000000000001
[ 977.289166][ T7696] R13: 0000000000000001 R14: 0000000000000001 R15: ffffea0000ac3440
[ 977.289550][ T7696] FS: 00007f7d03bb7700(0000) GS:ffff88802da00000(0000) knlGS:0000000000000000
[ 977.289982][ T7696] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 977.290304][ T7696] CR2: 00007f833c9a6c68 CR3: 0000000011584000 CR4: 00000000003506f0
[ 977.290688][ T7696] Call Trace:
[ 977.290852][ T7696] <TASK>
[ 977.290999][ T7696] ? die+0x31/0x80
[ 977.291190][ T7696] ? do_trap+0x232/0x430
[ 977.291400][ T7696] ? folio_end_read+0x17b/0x1a0
[ 977.291644][ T7696] ? folio_end_read+0x17b/0x1a0
[ 977.291912][ T7696] ? do_error_trap+0xf4/0x230
[ 977.292172][ T7696] ? folio_end_read+0x17b/0x1a0
[ 977.292415][ T7696] ? handle_invalid_op+0x34/0x40
[ 977.292660][ T7696] ? folio_end_read+0x17b/0x1a0
[ 977.292904][ T7696] ? exc_invalid_op+0x2d/0x40
[ 977.293140][ T7696] ? asm_exc_invalid_op+0x1a/0x20
[ 977.293392][ T7696] ? folio_end_read+0x17b/0x1a0
[ 977.293635][ T7696] ? folio_end_read+0x17b/0x1a0
[ 977.293882][ T7696] squashfs_copy_cache+0x1d7/0x550
[ 977.294174][ T7696] squashfs_read_folio+0xa13/0xc00
[ 977.294483][ T7696] ? __pfx_squashfs_read_folio+0x10/0x10
[ 977.294811][ T7696] ? __pfx_squashfs_read_folio+0x10/0x10
[ 977.295154][ T7696] filemap_read_folio+0xc0/0x2a0
[ 977.295457][ T7696] ? __pfx_filemap_read_folio+0x10/0x10
[ 977.295819][ T7696] ? page_cache_sync_ra+0x4b4/0x9c0
[ 977.296171][ T7696] filemap_get_pages+0x155c/0x1bd0
[ 977.296473][ T7696] ? current_time+0x79/0x380
[ 977.296744][ T7696] ? __pfx_filemap_get_pages+0x10/0x10
[ 977.297055][ T7696] filemap_read+0x3b6/0xd50
[ 977.297315][ T7696] ? __pfx_filemap_read+0x10/0x10
[ 977.297605][ T7696] ? pipe_write+0xf9f/0x1ae0
[ 977.297854][ T7696] ? __pfx_pipe_write+0x10/0x10
[ 977.298127][ T7696] ? lock_acquire+0x1b1/0x550
[ 977.298391][ T7696] ? __pfx_autoremove_wake_function+0x10/0x10
[ 977.298714][ T7696] generic_file_read_iter+0x344/0x450
[ 977.299008][ T7696] ? rw_verify_area+0xd0/0x700
[ 977.299283][ T7696] vfs_read+0x83e/0xba0
[ 977.299526][ T7696] ? __pfx_vfs_read+0x10/0x10
[ 977.299809][ T7696] ? __pfx_generic_fadvise+0x10/0x10
[ 977.300132][ T7696] ksys_read+0x122/0x240
[ 977.300361][ T7696] ? __pfx_ksys_read+0x10/0x10
[ 977.300630][ T7696] do_syscall_64+0x74/0x1c0
[ 977.300859][ T7696] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 977.301152][ T7696] RIP: 0033:0x7f7d034dbba0
[ 977.301372][ T7696] Code: 0b 31 c0 48 83 c4 08 e9 be fe ff ff 48 8d 3d 3f f0 08 00 e8 e2 ce 01 00 66 90 83 3d 34
[ 977.302300][ T7696] RSP: 002b:00007fffbb0b34a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[ 977.302705][ T7696] RAX: ffffffffffffffda RBX: 0000000000008000 RCX: 00007f7d034dbba0
[ 977.303088][ T7696] RDX: 0000000000008000 RSI: 0000000031e9c000 RDI: 0000000000000003
[ 977.303473][ T7696] RBP: 0000000000008000 R08: 0000000000000003 R09: 00007f7d0344b99a
[ 977.303874][ T7696] R10: 0000000000000002 R11: 0000000000000246 R12: 0000000031e9c000
[ 977.304283][ T7696] R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000008000
[ 977.304675][ T7696] </TASK>
[ 977.304827][ T7696] Modules linked in:
[ 977.305052][ T7696] ---[ end trace 0000000000000000 ]---
[ 977.305346][ T7696] RIP: 0010:folio_end_read+0x17b/0x1a0
[ 977.305640][ T7696] Code: e8 1a 62 ca ff 48 c7 c6 60 17 d8 8a 48 89 ef e8 2b d2 0e 00 0f 0b e8 04 62 ca ff 48 c8
[ 977.306747][ T7696] RSP: 0018:ffffc90007aa7710 EFLAGS: 00010293
[ 977.307125][ T7696] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffc90007aa75b8
[ 977.307610][ T7696] RDX: ffff888026320000 RSI: ffffffff81cd65bb RDI: ffff888026320444
[ 977.308117][ T7696] RBP: ffffea0000808b00 R08: 0000000000000000 R09: fffffbfff1efaf3a
[ 977.308541][ T7696] R10: ffffffff8f7d79d7 R11: 0000000000000001 R12: 0000000000000001
[ 977.308964][ T7696] R13: 0000000000000001 R14: 0000000000000001 R15: ffffea0000ac3440
[ 977.309385][ T7696] FS: 00007f7d03bb7700(0000) GS:ffff88802da00000(0000) knlGS:0000000000000000
[ 977.309842][ T7696] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 977.310165][ T7696] CR2: 00007f833c9a6c68 CR3: 0000000011584000 CR4: 00000000003506f0
[ 977.310551][ T7696] Kernel panic - not syncing: Fatal exception
[ 977.311300][ T7696] Kernel Offset: disabled
[ 977.311520][ T7696] Rebooting in 86400 seconds..
