ceph: cleanup the logic in ceph_invalidatepage

The invalidatepage code bails if it encounters a non-zero page offset. The
current logic that does is non-obvious with multiple if statements.

This should be logically and functionally equivalent.

Signed-off-by: Milosz Tanski <milosz@adfin.com>
Reviewed-by: Sage Weil <sage@inktank.com>
possible btrfs fix from chris
ceph: introduce i_truncate_mutex

I encountered below deadlock when running fsstress

wmtruncate work      truncate                 MDS
---------------  ------------------  --------------------------
                   lock i_mutex
                                      <- truncate file
lock i_mutex (blocked)
                                      <- revoking Fcb (filelock to MIX)
                   send request ->
                                         handle request (xlock filelock)

At the initial time, there are some dirty pages in the page cache.
When the kclient receives the truncate message, it reduces inode size
and creates some 'out of i_size' dirty pages. wmtruncate work can't
truncate these dirty pages because it's blocked by the i_mutex. Later
when the kclient receives the cap message that revokes Fcb caps, It
can't flush all dirty pages because writepages() only flushes dirty
pages within the inode size.

When the MDS handles the 'truncate' request from kclient, it waits
for the filelock to become stable. But the filelock is stuck in
unstable state because it can't finish revoking kclient's Fcb caps.

The truncate pagecache locking has already caused lots of trouble
for use. I think it's time simplify it by introducing a new mutex.
We use the new mutex to prevent concurrent truncate_inode_pages().
There is no need to worry about race between buffered write and
truncate_inode_pages(), because our "get caps" mechanism prevents
them from concurrent execution.

Reviewed-by: Sage Weil <sage@inktank.com>
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
ceph: fix request max size

ceph_check_caps() requests new max size only when there is Fw cap.
If we call check_max_size() while there is no Fw cap. It updates
i_wanted_max_size and calls ceph_check_caps(), but ceph_check_caps()
does nothing. Later when Fw cap is issued, we call check_max_size()
again. But i_wanted_max_size is equal to 'endoff' at this time, so
check_max_size() doesn't call ceph_check_caps() and we end up with
waiting for the new max size forever.

The fix is duplicate ceph_check_caps()'s "request max size" code in
check_max_size(), and make try_get_cap_refs() wait for the Fw cap
before retry requesting new max size.

This patch also removes the "endoff > (inode->i_size << 1)" check
in check_max_size(). It's useless because there is no corresponding
logic in ceph_check_caps().

Reviewed-by: Sage Weil <sage@inktank.com>
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
jbd2: debug journal_head additions and removals
ceph: punch hole support

This patch implements fallocate and punch hole support for Ceph kernel client.

Signed-off-by: Li Wang <liwang@ubuntukylin.com>
Signed-off-by: Yunchuan Wen <yunchuanwen@ubuntukylin.com>
libceph: fix error handling in handle_reply()

We've tried to fix the error paths in this function before, but there
is still a hidden goto in the ceph_decode_need() macro which goes to the
wrong place.  We need to release the "req" and unlock a mutex before
returning.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Sage Weil <sage@inktank.com>
libceph: potential NULL dereference in ceph_osdc_handle_map()

There are two places where we read "nr_maps" if both of them are set to
zero then we would hit a NULL dereference here.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Sage Weil <sage@inktank.com>
libceph: create_singlethread_workqueue() doesn't return ERR_PTRs

create_singlethread_workqueue() returns NULL on error, and it doesn't
return ERR_PTRs.

I tweaked the error handling a little to be consistent with earlier in
the function.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Sage Weil <sage@inktank.com>