From 6c93df5db628e710697c43bc1bd78a786549a548 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Fri, 15 Apr 2016 13:56:12 +0800 Subject: [PATCH] ceph: don't call truncate_pagecache in ceph_writepages_start truncate_pagecache() may decrease inode's reference. This can cause deadlock if inode's last reference is dropped and iput_final() wants to evict the inode. (evict() calls inode_wait_for_writeback(), which waits for ceph_writepages_start() to return). The fix is use work thead to truncate dirty pages. Also add 'forced umount' check to ceph_update_writeable_page(), which prevents new pages getting dirty. Signed-off-by: Yan, Zheng --- fs/ceph/addr.c | 14 ++++++++++++-- fs/ceph/inode.c | 11 +++++++++++ fs/ceph/mds_client.c | 22 +++++++++++++++------- 3 files changed, 38 insertions(+), 9 deletions(-) diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index f47418477629..d52e3bcfda7c 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -715,8 +715,11 @@ static int ceph_writepages_start(struct address_space *mapping, (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD")); if (ACCESS_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) { - pr_warn("writepage_start %p on forced umount\n", inode); - truncate_pagecache(inode, 0); + if (ci->i_wrbuffer_ref > 0) { + pr_warn_ratelimited( + "writepage_start %p %lld forced umount\n", + inode, ceph_ino(inode)); + } mapping_set_error(mapping, -EIO); return -EIO; /* we're in a forced umount, don't write! */ } @@ -1127,6 +1130,7 @@ static int ceph_update_writeable_page(struct file *file, struct page *page) { struct inode *inode = file_inode(file); + struct ceph_fs_client *fsc = ceph_inode_to_client(inode); struct ceph_inode_info *ci = ceph_inode(inode); loff_t page_off = pos & PAGE_MASK; int pos_in_page = pos & ~PAGE_MASK; @@ -1135,6 +1139,12 @@ static int ceph_update_writeable_page(struct file *file, int r; struct ceph_snap_context *snapc, *oldest; + if (ACCESS_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) { + dout(" page %p forced umount\n", page); + unlock_page(page); + return -EIO; + } + retry_locked: /* writepages currently holds page lock, but if we change that later, */ wait_on_page_writeback(page); diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index edfade037738..b906e02cddad 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -1623,10 +1623,21 @@ static void ceph_invalidate_work(struct work_struct *work) struct ceph_inode_info *ci = container_of(work, struct ceph_inode_info, i_pg_inv_work); struct inode *inode = &ci->vfs_inode; + struct ceph_fs_client *fsc = ceph_inode_to_client(inode); u32 orig_gen; int check = 0; mutex_lock(&ci->i_truncate_mutex); + + if (ACCESS_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) { + pr_warn_ratelimited("invalidate_pages %p %lld forced umount\n", + inode, ceph_ino(inode)); + mapping_set_error(inode->i_mapping, -EIO); + truncate_pagecache(inode, 0); + mutex_unlock(&ci->i_truncate_mutex); + goto out; + } + spin_lock(&ci->i_ceph_lock); dout("invalidate_pages %p gen %d revoking %d\n", inode, ci->i_rdcache_gen, ci->i_rdcache_revoking); diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 1e5965d17cb1..cbe6c0afdadc 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -1120,9 +1120,11 @@ out: static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg) { + struct ceph_fs_client *fsc = (struct ceph_fs_client *)arg; struct ceph_inode_info *ci = ceph_inode(inode); LIST_HEAD(to_remove); - int drop = 0; + bool drop = false; + bool invalidate = false; dout("removing cap %p, ci is %p, inode is %p\n", cap, ci, &ci->vfs_inode); @@ -1130,11 +1132,14 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap, __ceph_remove_cap(cap, false); if (!ci->i_auth_cap) { struct ceph_cap_flush *cf; - struct ceph_mds_client *mdsc = - ceph_sb_to_client(inode->i_sb)->mdsc; + struct ceph_mds_client *mdsc = fsc->mdsc; ci->i_ceph_flags |= CEPH_I_CAP_DROPPED; + if (ci->i_wrbuffer_ref > 0 && + ACCESS_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) + invalidate = true; + while (true) { struct rb_node *n = rb_first(&ci->i_cap_flush_tree); if (!n) @@ -1156,7 +1161,7 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap, inode, ceph_ino(inode)); ci->i_dirty_caps = 0; list_del_init(&ci->i_dirty_item); - drop = 1; + drop = true; } if (!list_empty(&ci->i_flushing_item)) { pr_warn_ratelimited( @@ -1166,7 +1171,7 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap, ci->i_flushing_caps = 0; list_del_init(&ci->i_flushing_item); mdsc->num_cap_flushing--; - drop = 1; + drop = true; } spin_unlock(&mdsc->cap_dirty_lock); @@ -1185,6 +1190,8 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap, } wake_up_all(&ci->i_cap_wq); + if (invalidate) + ceph_queue_invalidate(inode); if (drop) iput(inode); return 0; @@ -1195,12 +1202,13 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap, */ static void remove_session_caps(struct ceph_mds_session *session) { + struct ceph_fs_client *fsc = session->s_mdsc->fsc; + struct super_block *sb = fsc->sb; dout("remove_session_caps on %p\n", session); - iterate_session_caps(session, remove_session_caps_cb, NULL); + iterate_session_caps(session, remove_session_caps_cb, fsc); spin_lock(&session->s_cap_lock); if (session->s_nr_caps > 0) { - struct super_block *sb = session->s_mdsc->fsc->sb; struct inode *inode; struct ceph_cap *cap, *prev = NULL; struct ceph_vino vino; -- 2.20.1