From ce23ac8de8fc798129b557034031732483ae8e4f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marcin=20Wcis=C5=82o?= Date: Mon, 1 Dec 2025 20:17:11 +0100 Subject: [PATCH 1/3] Bluetooth: hci_core: Fix use-after-free in vhci_flush() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit jira VULN-72347 cve CVE-2025-38250 commit-author Kuniyuki Iwashima commit 1d6123102e9fbedc8d25bf4731da6d513173e49e upstream-diff Context conflicts resolved in 'hci_unregister_dev()' syzbot reported use-after-free in vhci_flush() without repro. [0] From the splat, a thread close()d a vhci file descriptor while its device was being used by iotcl() on another thread. Once the last fd refcnt is released, vhci_release() calls hci_unregister_dev(), hci_free_dev(), and kfree() for struct vhci_data, which is set to hci_dev->dev->driver_data. The problem is that there is no synchronisation after unlinking hdev from hci_dev_list in hci_unregister_dev(). There might be another thread still accessing the hdev which was fetched before the unlink operation. We can use SRCU for such synchronisation. Let's run hci_dev_reset() under SRCU and wait for its completion in hci_unregister_dev(). Another option would be to restore hci_dev->destruct(), which was removed in commit 587ae086f6e4 ("Bluetooth: Remove unused hci-destruct cb"). However, this would not be a good solution, as we should not run hci_unregister_dev() while there are in-flight ioctl() requests, which could lead to another data-race KCSAN splat. Note that other drivers seem to have the same problem, for exmaple, virtbt_remove(). [0]: BUG: KASAN: slab-use-after-free in skb_queue_empty_lockless include/linux/skbuff.h:1891 [inline] BUG: KASAN: slab-use-after-free in skb_queue_purge_reason+0x99/0x360 net/core/skbuff.c:3937 Read of size 8 at addr ffff88807cb8d858 by task syz.1.219/6718 CPU: 1 UID: 0 PID: 6718 Comm: syz.1.219 Not tainted 6.16.0-rc1-syzkaller-00196-g08207f42d3ff #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 skb_queue_empty_lockless include/linux/skbuff.h:1891 [inline] skb_queue_purge_reason+0x99/0x360 net/core/skbuff.c:3937 skb_queue_purge include/linux/skbuff.h:3368 [inline] vhci_flush+0x44/0x50 drivers/bluetooth/hci_vhci.c:69 hci_dev_do_reset net/bluetooth/hci_core.c:552 [inline] hci_dev_reset+0x420/0x5c0 net/bluetooth/hci_core.c:592 sock_do_ioctl+0xd9/0x300 net/socket.c:1190 sock_ioctl+0x576/0x790 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcf5b98e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fcf5c7b9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fcf5bbb6160 RCX: 00007fcf5b98e929 RDX: 0000000000000000 RSI: 00000000400448cb RDI: 0000000000000009 RBP: 00007fcf5ba10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fcf5bbb6160 R15: 00007ffd6353d528 Allocated by task 6535: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] vhci_open+0x57/0x360 drivers/bluetooth/hci_vhci.c:635 misc_open+0x2bc/0x330 drivers/char/misc.c:161 chrdev_open+0x4c9/0x5e0 fs/char_dev.c:414 do_dentry_open+0xdf0/0x1970 fs/open.c:964 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:3887 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4046 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6535: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x18e/0x440 mm/slub.c:4842 vhci_release+0xbc/0xd0 drivers/bluetooth/hci_vhci.c:671 __fput+0x44c/0xa70 fs/file_table.c:465 task_work_run+0x1d1/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6ad/0x22e0 kernel/exit.c:955 do_group_exit+0x21c/0x2d0 kernel/exit.c:1104 __do_sys_exit_group kernel/exit.c:1115 [inline] __se_sys_exit_group kernel/exit.c:1113 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1113 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807cb8d800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 88 bytes inside of freed 1024-byte region [ffff88807cb8d800, ffff88807cb8dc00) Fixes: bf18c7118cf8 ("Bluetooth: vhci: Free driver_data on file release") Reported-by: syzbot+2faa4825e556199361f9@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f62d64848fc4c7c30cd6 Signed-off-by: Kuniyuki Iwashima Acked-by: Paul Menzel Signed-off-by: Luiz Augusto von Dentz (cherry picked from commit 1d6123102e9fbedc8d25bf4731da6d513173e49e) Signed-off-by: Marcin Wcisło --- include/net/bluetooth/hci_core.h | 2 ++ net/bluetooth/hci_core.c | 34 ++++++++++++++++++++++++++++---- 2 files changed, 32 insertions(+), 4 deletions(-) diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h index e7862903187d8..5833eccdb881a 100644 --- a/include/net/bluetooth/hci_core.h +++ b/include/net/bluetooth/hci_core.h @@ -28,6 +28,7 @@ #include #include #include +#include #include #include @@ -345,6 +346,7 @@ struct amp_assoc { struct hci_dev { struct list_head list; + struct srcu_struct srcu; struct mutex lock; char name[8]; diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index fd3145e81e87f..52ccb0e8d9f2c 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -109,7 +109,7 @@ static int hci_linkpol_req(struct hci_request *req, unsigned long opt) /* Get HCI device by index. * Device is held on return. */ -struct hci_dev *hci_dev_get(int index) +static struct hci_dev *__hci_dev_get(int index, int *srcu_index) { struct hci_dev *hdev = NULL, *d; @@ -122,6 +122,8 @@ struct hci_dev *hci_dev_get(int index) list_for_each_entry(d, &hci_dev_list, list) { if (d->id == index) { hdev = hci_dev_hold(d); + if (srcu_index) + *srcu_index = srcu_read_lock(&d->srcu); break; } } @@ -129,6 +131,22 @@ struct hci_dev *hci_dev_get(int index) return hdev; } +struct hci_dev *hci_dev_get(int index) +{ + return __hci_dev_get(index, NULL); +} + +static struct hci_dev *hci_dev_get_srcu(int index, int *srcu_index) +{ + return __hci_dev_get(index, srcu_index); +} + +static void hci_dev_put_srcu(struct hci_dev *hdev, int srcu_index) +{ + srcu_read_unlock(&hdev->srcu, srcu_index); + hci_dev_put(hdev); +} + /* ---- Inquiry support ---- */ bool hci_discovery_active(struct hci_dev *hdev) @@ -639,9 +657,9 @@ static int hci_dev_do_reset(struct hci_dev *hdev) int hci_dev_reset(__u16 dev) { struct hci_dev *hdev; - int err; + int err, srcu_index; - hdev = hci_dev_get(dev); + hdev = hci_dev_get_srcu(dev, &srcu_index); if (!hdev) return -ENODEV; @@ -663,7 +681,7 @@ int hci_dev_reset(__u16 dev) err = hci_dev_do_reset(hdev); done: - hci_dev_put(hdev); + hci_dev_put_srcu(hdev, srcu_index); return err; } @@ -2432,6 +2450,11 @@ struct hci_dev *hci_alloc_dev_priv(int sizeof_priv) if (!hdev) return NULL; + if (init_srcu_struct(&hdev->srcu)) { + kfree(hdev); + return NULL; + } + hdev->pkt_type = (HCI_DM1 | HCI_DH1 | HCI_HV1); hdev->esco_type = (ESCO_HV1); hdev->link_mode = (HCI_LM_ACCEPT); @@ -2684,6 +2707,9 @@ void hci_unregister_dev(struct hci_dev *hdev) list_del(&hdev->list); write_unlock(&hci_dev_list_lock); + synchronize_srcu(&hdev->srcu); + cleanup_srcu_struct(&hdev->srcu); + cancel_work_sync(&hdev->power_on); hci_cmd_sync_clear(hdev); From 381e0b9aa22da69bb2ce1aa39fdb31a60fd2b57e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marcin=20Wcis=C5=82o?= Date: Tue, 2 Dec 2025 00:30:52 +0100 Subject: [PATCH 2/3] nfs: fold nfs_page_group_lock_subrequests into nfs_lock_and_join_requests MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit jira VULN-136535 cve-pre CVE-2025-39697 commit-author Christoph Hellwig commit 25edbcac6e32eab345e470d56ca9974a577b878b upstream-diff Used linux-5.15.y backport fd947b71cc1b86c4731f8d470f5ab5df94e838d8 as baseline, then accounted in 'nfs_lock_and_join_requests()' for the missing b193a78ddb5ee7dba074d3f28dc050069ba083c0 backport. Fold nfs_page_group_lock_subrequests into nfs_lock_and_join_requests to prepare for future changes to this code, and move the helpers to write.c as well. Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Signed-off-by: Anna Schumaker Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman (cherry picked from commit fd947b71cc1b86c4731f8d470f5ab5df94e838d8) Signed-off-by: Marcin Wcisło --- fs/nfs/pagelist.c | 77 ---------------------------------------- fs/nfs/write.c | 74 ++++++++++++++++++++++++++++++++++---- include/linux/nfs_page.h | 1 - 3 files changed, 68 insertions(+), 84 deletions(-) diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index 317cedfa52bf6..99e756139a5d3 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -167,83 +167,6 @@ nfs_page_group_lock_head(struct nfs_page *req) return head; } -/* - * nfs_unroll_locks - unlock all newly locked reqs and wait on @req - * @head: head request of page group, must be holding head lock - * @req: request that couldn't lock and needs to wait on the req bit lock - * - * This is a helper function for nfs_lock_and_join_requests - * returns 0 on success, < 0 on error. - */ -static void -nfs_unroll_locks(struct nfs_page *head, struct nfs_page *req) -{ - struct nfs_page *tmp; - - /* relinquish all the locks successfully grabbed this run */ - for (tmp = head->wb_this_page ; tmp != req; tmp = tmp->wb_this_page) { - if (!kref_read(&tmp->wb_kref)) - continue; - nfs_unlock_and_release_request(tmp); - } -} - -/* - * nfs_page_group_lock_subreq - try to lock a subrequest - * @head: head request of page group - * @subreq: request to lock - * - * This is a helper function for nfs_lock_and_join_requests which - * must be called with the head request and page group both locked. - * On error, it returns with the page group unlocked. - */ -static int -nfs_page_group_lock_subreq(struct nfs_page *head, struct nfs_page *subreq) -{ - int ret; - - if (!kref_get_unless_zero(&subreq->wb_kref)) - return 0; - while (!nfs_lock_request(subreq)) { - nfs_page_group_unlock(head); - ret = nfs_wait_on_request(subreq); - if (!ret) - ret = nfs_page_group_lock(head); - if (ret < 0) { - nfs_unroll_locks(head, subreq); - nfs_release_request(subreq); - return ret; - } - } - return 0; -} - -/* - * nfs_page_group_lock_subrequests - try to lock the subrequests - * @head: head request of page group - * - * This is a helper function for nfs_lock_and_join_requests which - * must be called with the head request locked. - */ -int nfs_page_group_lock_subrequests(struct nfs_page *head) -{ - struct nfs_page *subreq; - int ret; - - ret = nfs_page_group_lock(head); - if (ret < 0) - return ret; - /* lock each request in the page group */ - for (subreq = head->wb_this_page; subreq != head; - subreq = subreq->wb_this_page) { - ret = nfs_page_group_lock_subreq(head, subreq); - if (ret < 0) - return ret; - } - nfs_page_group_unlock(head); - return 0; -} - /* * nfs_page_set_headlock - set the request PG_HEADLOCK * @req: request that is to be locked diff --git a/fs/nfs/write.c b/fs/nfs/write.c index eb39ba74a570b..e6f69bf978569 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -547,6 +547,57 @@ nfs_join_page_group(struct nfs_page *head, struct inode *inode) nfs_destroy_unlinked_subrequests(destroy_list, head, inode); } +/* + * nfs_unroll_locks - unlock all newly locked reqs and wait on @req + * @head: head request of page group, must be holding head lock + * @req: request that couldn't lock and needs to wait on the req bit lock + * + * This is a helper function for nfs_lock_and_join_requests + * returns 0 on success, < 0 on error. + */ +static void +nfs_unroll_locks(struct nfs_page *head, struct nfs_page *req) +{ + struct nfs_page *tmp; + + /* relinquish all the locks successfully grabbed this run */ + for (tmp = head->wb_this_page ; tmp != req; tmp = tmp->wb_this_page) { + if (!kref_read(&tmp->wb_kref)) + continue; + nfs_unlock_and_release_request(tmp); + } +} + +/* + * nfs_page_group_lock_subreq - try to lock a subrequest + * @head: head request of page group + * @subreq: request to lock + * + * This is a helper function for nfs_lock_and_join_requests which + * must be called with the head request and page group both locked. + * On error, it returns with the page group unlocked. + */ +static int +nfs_page_group_lock_subreq(struct nfs_page *head, struct nfs_page *subreq) +{ + int ret; + + if (!kref_get_unless_zero(&subreq->wb_kref)) + return 0; + while (!nfs_lock_request(subreq)) { + nfs_page_group_unlock(head); + ret = nfs_wait_on_request(subreq); + if (!ret) + ret = nfs_page_group_lock(head); + if (ret < 0) { + nfs_unroll_locks(head, subreq); + nfs_release_request(subreq); + return ret; + } + } + return 0; +} + /* * nfs_lock_and_join_requests - join all subreqs to the head req * @page: the page used to lookup the "page group" of nfs_page structures @@ -566,7 +617,7 @@ static struct nfs_page * nfs_lock_and_join_requests(struct page *page) { struct inode *inode = page_file_mapping(page)->host; - struct nfs_page *head; + struct nfs_page *head, *subreq; int ret; /* @@ -578,16 +629,27 @@ nfs_lock_and_join_requests(struct page *page) if (IS_ERR_OR_NULL(head)) return head; + ret = nfs_page_group_lock(head); + if (ret < 0) + goto out_unlock; + /* lock each request in the page group */ - ret = nfs_page_group_lock_subrequests(head); - if (ret < 0) { - nfs_unlock_and_release_request(head); - return ERR_PTR(ret); + for (subreq = head->wb_this_page; + subreq != head; + subreq = subreq->wb_this_page) { + ret = nfs_page_group_lock_subreq(head, subreq); + if (ret < 0) + goto out_unlock; } - nfs_join_page_group(head, inode); + nfs_page_group_unlock(head); + nfs_join_page_group(head, inode); return head; + +out_unlock: + nfs_unlock_and_release_request(head); + return ERR_PTR(ret); } static void nfs_write_error(struct nfs_page *req, int error) diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h index f0373a6cb5fb6..8b4f8d765cfb1 100644 --- a/include/linux/nfs_page.h +++ b/include/linux/nfs_page.h @@ -144,7 +144,6 @@ extern int nfs_wait_on_request(struct nfs_page *); extern void nfs_unlock_request(struct nfs_page *req); extern void nfs_unlock_and_release_request(struct nfs_page *); extern struct nfs_page *nfs_page_group_lock_head(struct nfs_page *req); -extern int nfs_page_group_lock_subrequests(struct nfs_page *head); extern void nfs_join_page_group(struct nfs_page *head, struct inode *inode); extern int nfs_page_group_lock(struct nfs_page *); extern void nfs_page_group_unlock(struct nfs_page *); From 778c42066fc515570b11c98a4af705a99c5e3996 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marcin=20Wcis=C5=82o?= Date: Tue, 2 Dec 2025 01:01:03 +0100 Subject: [PATCH 3/3] NFS: Fix a race when updating an existing write MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit jira VULN-136535 cve CVE-2025-39697 commit-author Trond Myklebust commit 76d2e3890fb169168c73f2e4f8375c7cc24a765e upstream-diff Used linux-5.15.y backport f230d40147cc37eb3aef4d50e2e2c06ea73d9a77, which applied cleanly After nfs_lock_and_join_requests() tests for whether the request is still attached to the mapping, nothing prevents a call to nfs_inode_remove_request() from succeeding until we actually lock the page group. The reason is that whoever called nfs_inode_remove_request() doesn't necessarily have a lock on the page group head. So in order to avoid races, let's take the page group lock earlier in nfs_lock_and_join_requests(), and hold it across the removal of the request in nfs_inode_remove_request(). Reported-by: Jeff Layton Tested-by: Joe Quanaim Tested-by: Andrew Steffen Reviewed-by: Jeff Layton Fixes: bd37d6fce184 ("NFSv4: Convert nfs_lock_and_join_requests() to use nfs_page_find_head_request()") Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman (cherry picked from commit f230d40147cc37eb3aef4d50e2e2c06ea73d9a77) Signed-off-by: Marcin Wcisło --- fs/nfs/pagelist.c | 9 +++--- fs/nfs/write.c | 66 ++++++++++++++-------------------------- include/linux/nfs_page.h | 1 + 3 files changed, 29 insertions(+), 47 deletions(-) diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index 99e756139a5d3..6afa4195113e0 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -233,13 +233,14 @@ nfs_page_group_unlock(struct nfs_page *req) nfs_page_clear_headlock(req); } -/* - * nfs_page_group_sync_on_bit_locked +/** + * nfs_page_group_sync_on_bit_locked - Test if all requests have @bit set + * @req: request in page group + * @bit: PG_* bit that is used to sync page group * * must be called with page group lock held */ -static bool -nfs_page_group_sync_on_bit_locked(struct nfs_page *req, unsigned int bit) +bool nfs_page_group_sync_on_bit_locked(struct nfs_page *req, unsigned int bit) { struct nfs_page *head = req->wb_head; struct nfs_page *tmp; diff --git a/fs/nfs/write.c b/fs/nfs/write.c index e6f69bf978569..2df426dac8ae7 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -154,20 +154,10 @@ nfs_page_set_inode_ref(struct nfs_page *req, struct inode *inode) } } -static int -nfs_cancel_remove_inode(struct nfs_page *req, struct inode *inode) +static void nfs_cancel_remove_inode(struct nfs_page *req, struct inode *inode) { - int ret; - - if (!test_bit(PG_REMOVE, &req->wb_flags)) - return 0; - ret = nfs_page_group_lock(req); - if (ret) - return ret; if (test_and_clear_bit(PG_REMOVE, &req->wb_flags)) nfs_page_set_inode_ref(req, inode); - nfs_page_group_unlock(req); - return 0; } static struct nfs_page * @@ -239,36 +229,6 @@ static struct nfs_page *nfs_page_find_head_request(struct page *page) return req; } -static struct nfs_page *nfs_find_and_lock_page_request(struct page *page) -{ - struct inode *inode = page_file_mapping(page)->host; - struct nfs_page *req, *head; - int ret; - - for (;;) { - req = nfs_page_find_head_request(page); - if (!req) - return req; - head = nfs_page_group_lock_head(req); - if (head != req) - nfs_release_request(req); - if (IS_ERR(head)) - return head; - ret = nfs_cancel_remove_inode(head, inode); - if (ret < 0) { - nfs_unlock_and_release_request(head); - return ERR_PTR(ret); - } - /* Ensure that nobody removed the request before we locked it */ - if (head == nfs_page_private_request(page)) - break; - if (PageSwapCache(page)) - break; - nfs_unlock_and_release_request(head); - } - return head; -} - /* Adjust the file length if we're writing beyond the end */ static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count) { @@ -625,14 +585,32 @@ nfs_lock_and_join_requests(struct page *page) * reference to the whole page group - the group will not be destroyed * until the head reference is released. */ - head = nfs_find_and_lock_page_request(page); +retry: + head = nfs_page_find_head_request(page); if (IS_ERR_OR_NULL(head)) return head; + while (!nfs_lock_request(head)) { + ret = nfs_wait_on_request(head); + if (ret < 0) { + nfs_release_request(head); + return ERR_PTR(ret); + } + } + ret = nfs_page_group_lock(head); if (ret < 0) goto out_unlock; + /* Ensure that nobody removed the request before we locked it */ + if (head != nfs_page_private_request(page) && !PageSwapCache(page)) { + nfs_page_group_unlock(head); + nfs_unlock_and_release_request(head); + goto retry; + } + + nfs_cancel_remove_inode(head, inode); + /* lock each request in the page group */ for (subreq = head->wb_this_page; subreq != head; @@ -850,7 +828,8 @@ static void nfs_inode_remove_request(struct nfs_page *req) struct nfs_inode *nfsi = NFS_I(inode); struct nfs_page *head; - if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) { + nfs_page_group_lock(req); + if (nfs_page_group_sync_on_bit_locked(req, PG_REMOVE)) { head = req->wb_head; spin_lock(&mapping->private_lock); @@ -861,6 +840,7 @@ static void nfs_inode_remove_request(struct nfs_page *req) } spin_unlock(&mapping->private_lock); } + nfs_page_group_unlock(req); if (test_and_clear_bit(PG_INODE_REF, &req->wb_flags)) { nfs_release_request(req); diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h index 8b4f8d765cfb1..d6e6a9376ee45 100644 --- a/include/linux/nfs_page.h +++ b/include/linux/nfs_page.h @@ -148,6 +148,7 @@ extern void nfs_join_page_group(struct nfs_page *head, struct inode *inode); extern int nfs_page_group_lock(struct nfs_page *); extern void nfs_page_group_unlock(struct nfs_page *); extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int); +extern bool nfs_page_group_sync_on_bit_locked(struct nfs_page *, unsigned int); extern int nfs_page_set_headlock(struct nfs_page *req); extern void nfs_page_clear_headlock(struct nfs_page *req); extern bool nfs_async_iocounter_wait(struct rpc_task *, struct nfs_lock_context *);