diff options
| author | David Howells <dhowells@redhat.com> | 2017-01-18 15:29:25 +0100 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2017-01-31 19:23:09 +0100 |
| commit | 6bdded59c8933940ac7e5b416448276ac89d1144 (patch) | |
| tree | 0620c0018aef6e596711114622e40d2f408e4bd3 | |
| parent | FS-Cache: Initialise stores_lock in netfs cookie (diff) | |
| download | linux-6bdded59c8933940ac7e5b416448276ac89d1144.tar.xz linux-6bdded59c8933940ac7e5b416448276ac89d1144.zip | |
fscache: Clear outstanding writes when disabling a cookie
fscache_disable_cookie() needs to clear the outstanding writes on the
cookie it's disabling because they cannot be completed after.
Without this, fscache_nfs_open_file() gets stuck because it disables the
cookie when the file is opened for writing but can't uncache the pages till
afterwards - otherwise there's a race between the open routine and anyone
who already has it open R/O and is still reading from it.
Looking in /proc/pid/stack of the offending process shows:
[<ffffffffa0142883>] __fscache_wait_on_page_write+0x82/0x9b [fscache]
[<ffffffffa014336e>] __fscache_uncache_all_inode_pages+0x91/0xe1 [fscache]
[<ffffffffa01740fa>] nfs_fscache_open_file+0x59/0x9e [nfs]
[<ffffffffa01ccf41>] nfs4_file_open+0x17f/0x1b8 [nfsv4]
[<ffffffff8117350e>] do_dentry_open+0x16d/0x2b7
[<ffffffff811743ac>] vfs_open+0x5c/0x65
[<ffffffff81184185>] path_openat+0x785/0x8fb
[<ffffffff81184343>] do_filp_open+0x48/0x9e
[<ffffffff81174710>] do_sys_open+0x13b/0x1cb
[<ffffffff811747b9>] SyS_open+0x19/0x1b
[<ffffffff81001c44>] do_syscall_64+0x80/0x17a
[<ffffffff8165c2da>] return_from_SYSCALL_64+0x0/0x7a
[<ffffffffffffffff>] 0xffffffffffffffff
Reported-by: Jianhong Yin <jiyin@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/fscache/cookie.c | 5 | ||||
| -rw-r--r-- | fs/fscache/object.c | 6 |
2 files changed, 11 insertions, 0 deletions
diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c index 4304072161aa..40d61077bead 100644 --- a/fs/fscache/cookie.c +++ b/fs/fscache/cookie.c @@ -542,6 +542,7 @@ void __fscache_disable_cookie(struct fscache_cookie *cookie, bool invalidate) hlist_for_each_entry(object, &cookie->backing_objects, cookie_link) { if (invalidate) set_bit(FSCACHE_OBJECT_RETIRED, &object->flags); + clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags); fscache_raise_event(object, FSCACHE_OBJECT_EV_KILL); } } else { @@ -560,6 +561,10 @@ void __fscache_disable_cookie(struct fscache_cookie *cookie, bool invalidate) wait_on_atomic_t(&cookie->n_active, fscache_wait_atomic_t, TASK_UNINTERRUPTIBLE); + /* Make sure any pending writes are cancelled. */ + if (cookie->def->type != FSCACHE_COOKIE_TYPE_INDEX) + fscache_invalidate_writes(cookie); + /* Reset the cookie state if it wasn't relinquished */ if (!test_bit(FSCACHE_COOKIE_RELINQUISHED, &cookie->flags)) { atomic_inc(&cookie->n_active); diff --git a/fs/fscache/object.c b/fs/fscache/object.c index 9e792e30f4db..be02a086ed9b 100644 --- a/fs/fscache/object.c +++ b/fs/fscache/object.c @@ -645,6 +645,12 @@ static const struct fscache_state *fscache_kill_object(struct fscache_object *ob fscache_mark_object_dead(object); object->oob_event_mask = 0; + if (test_bit(FSCACHE_OBJECT_RETIRED, &object->flags)) { + /* Reject any new read/write ops and abort any that are pending. */ + clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags); + fscache_cancel_all_ops(object); + } + if (list_empty(&object->dependents) && object->n_ops == 0 && object->n_children == 0) |