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ceph: don't call truncate_pagecache in ceph_writepages_start

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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 <zyan@redhat.com>
This commit is contained in:
Yan, Zheng 2016-04-15 13:56:12 +08:00 committed by Ilya Dryomov
parent 77310320c2
commit 6c93df5db6
3 changed files with 38 additions and 9 deletions
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14
fs/ceph/addr.c
View file

@ -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);

11
fs/ceph/inode.c
View file

@ -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);

22
fs/ceph/mds_client.c
View file

@ -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;