From: Zhang Xiaoxu zhangxiaoxu5@huawei.com
[ Upstream commit 95a3d8f3af9b0d63b43f221b630beaab9739d13a ]
When xfstests generic/451, there is an BUG at mm/memcontrol.c: page:ffffea000560f2c0 refcount:2 mapcount:0 mapping:000000008544e0ea index:0xf mapping->aops:cifs_addr_ops dentry name:"tst-aio-dio-cycle-write.451" flags: 0x2fffff80000001(locked) raw: 002fffff80000001 ffffc90002023c50 ffffea0005280088 ffff88815cda0210 raw: 000000000000000f 0000000000000000 00000002ffffffff ffff88817287d000 page dumped because: VM_BUG_ON_PAGE(page->mem_cgroup) page->mem_cgroup:ffff88817287d000 ------------[ cut here ]------------ kernel BUG at mm/memcontrol.c:2659! invalid opcode: 0000 [#1] SMP CPU: 2 PID: 2038 Comm: xfs_io Not tainted 5.8.0-rc1 #44 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_ 073836-buildvm-ppc64le-16.ppc.4 RIP: 0010:commit_charge+0x35/0x50 Code: 0d 48 83 05 54 b2 02 05 01 48 89 77 38 c3 48 c7 c6 78 4a ea ba 48 83 05 38 b2 02 05 01 e8 63 0d9 RSP: 0018:ffffc90002023a50 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff88817287d000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff88817ac97ea0 RDI: ffff88817ac97ea0 RBP: ffffea000560f2c0 R08: 0000000000000203 R09: 0000000000000005 R10: 0000000000000030 R11: ffffc900020237a8 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000001 R15: ffff88815a1272c0 FS: 00007f5071ab0800(0000) GS:ffff88817ac80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055efcd5ca000 CR3: 000000015d312000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mem_cgroup_charge+0x166/0x4f0 __add_to_page_cache_locked+0x4a9/0x710 add_to_page_cache_locked+0x15/0x20 cifs_readpages+0x217/0x1270 read_pages+0x29a/0x670 page_cache_readahead_unbounded+0x24f/0x390 __do_page_cache_readahead+0x3f/0x60 ondemand_readahead+0x1f1/0x470 page_cache_async_readahead+0x14c/0x170 generic_file_buffered_read+0x5df/0x1100 generic_file_read_iter+0x10c/0x1d0 cifs_strict_readv+0x139/0x170 new_sync_read+0x164/0x250 __vfs_read+0x39/0x60 vfs_read+0xb5/0x1e0 ksys_pread64+0x85/0xf0 __x64_sys_pread64+0x22/0x30 do_syscall_64+0x69/0x150 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f5071fcb1af Code: Bad RIP value. RSP: 002b:00007ffde2cdb8e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000011 RAX: ffffffffffffffda RBX: 00007ffde2cdb990 RCX: 00007f5071fcb1af RDX: 0000000000001000 RSI: 000055efcd5ca000 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000001000 R11: 0000000000000293 R12: 0000000000000001 R13: 000000000009f000 R14: 0000000000000000 R15: 0000000000001000 Modules linked in: ---[ end trace 725fa14a3e1af65c ]---
Since commit 3fea5a499d57 ("mm: memcontrol: convert page cache to a new mem_cgroup_charge() API") not cancel the page charge, the pages maybe double add to pagecache: thread1 | thread2 cifs_readpages readpages_get_pages add_to_page_cache_locked(head,index=n)=0 | readpages_get_pages | add_to_page_cache_locked(head,index=n+1)=0 add_to_page_cache_locked(head, index=n+1)=-EEXIST then, will next loop with list head page's index=n+1 and the page->mapping not NULL readpages_get_pages add_to_page_cache_locked(head, index=n+1) commit_charge VM_BUG_ON_PAGE
So, we should not do the next loop when any page add to page cache failed.
Reported-by: Hulk Robot hulkci@huawei.com Signed-off-by: Zhang Xiaoxu zhangxiaoxu5@huawei.com Signed-off-by: Steve French stfrench@microsoft.com Acked-by: Ronnie Sahlberg lsahlber@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/cifs/file.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/fs/cifs/file.c b/fs/cifs/file.c index dca78b6e9ea32..24508b69e78b7 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -3531,7 +3531,8 @@ readpages_get_pages(struct address_space *mapping, struct list_head *page_list, break;
__SetPageLocked(page); - if (add_to_page_cache_locked(page, mapping, page->index, gfp)) { + rc = add_to_page_cache_locked(page, mapping, page->index, gfp); + if (rc) { __ClearPageLocked(page); break; } @@ -3547,6 +3548,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, struct list_head *page_list, unsigned num_pages) { int rc; + int err = 0; struct list_head tmplist; struct cifsFileInfo *open_file = file->private_data; struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file); @@ -3587,7 +3589,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, * the order of declining indexes. When we put the pages in * the rdata->pages, then we want them in increasing order. */ - while (!list_empty(page_list)) { + while (!list_empty(page_list) && !err) { unsigned int i, nr_pages, bytes, rsize; loff_t offset; struct page *page, *tpage; @@ -3610,9 +3612,10 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, return 0; }
- rc = readpages_get_pages(mapping, page_list, rsize, &tmplist, + nr_pages = 0; + err = readpages_get_pages(mapping, page_list, rsize, &tmplist, &nr_pages, &offset, &bytes); - if (rc) { + if (!nr_pages) { add_credits_and_wake_if(server, credits, 0); break; }