Signed-off-by: NYan, Zheng <zyan@redhat.com>

writepage() can be interrupted when it's called by direct memory
reclaimer (the direct memory relaimer is killed). To avoid lossing
data, we redirty the page.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

ceph_update_writeable_page() is used by ceph_write_begin(). It beaks
atomicity of write operation if it's interruptible.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Ceph_osdc_wait_request() is used when cephfs issues sync IO. In most
cases, the sync IO should be uninterruptible. The fix is use killale
wait function in ceph_osdc_wait_request().
Signed-off-by: NYan, Zheng <zyan@redhat.com>

when ceph_update_writeable_page() return -EAGAIN, caller should
lock the page and call ceph_update_writeable_page() again.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Signed-off-by: NYan, Zheng <zyan@redhat.com>

Fault and page_mkwrite are supposed to be uninterruptable. But they
call ceph functions that are interruptible. So they should block
signals before calling functions that are interruptible
Signed-off-by: NYan, Zheng <zyan@redhat.com>

This patch makes serverl logical caculation functions return bool to
improve readability due to these particular functions only using 0/1
as their return value.

No functional change.
Signed-off-by: NZhang Zhuoyu <zhangzhuoyu@cmss.chinamobile.com>

A mds bug can cause symlink's size to be truncated to zero.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

check if number of splits in i_fragtree is equal to number of splits
in mds reply
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Nodes in i_fragtree are sorted according to ceph_compare_frag().
It means frag node in i_fragtree always follow its direct parent
node. To check if a leaf node is valid, we just need to check if
it's child of previous split node.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

-1 is CDIR_AUTH_PARENT, it means dir's auth mds is the same as
inode's auth mds
Signed-off-by: NYan, Zheng <zyan@redhat.com>

The algorithm that updates i_fragtree relies on that the frag tree
splits in mds reply are of the same order of i_fragtree. This is not
true because current MDS encodes frag tree splits in ascending order
of (unsigned)frag_t. But nodes in i_fragtree are sorted according to
ceph_frag_compare().

The fix is sort the frag tree splits first, then updates i_fragtree.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Signed-off-by: NYan, Zheng <zyan@redhat.com>

If MDS sorts dentries in dirfrag in hash order, we use hash value to
compose dentry offset. dentry offset is:

  (0xff << 52) | ((24 bits hash) << 28) |
  (the nth entry hash hash collision)

This offset is stable across directory fragmentation. This alos means
there is no need to reset readdir offset if directory get fragmented
in the middle of readdir.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Forward seek within same frag does not update fi->last_name, it will
not affect contents of later readdir reply. So there is no need to
forbid marking directory complete
Signed-off-by: NYan, Zheng <zyan@redhat.com>

This is preparation for using hash value as dentry 'offset'
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Set a flag in readdir request, which indicates that client interprets
'end/complete' as bit flags. So that mds can reply additional flags in
readdir reply.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

This avoids defining multiple arrays for entries in readdir reply
Signed-off-by: NYan, Zheng <zyan@redhat.com>

don't distinguish leftmost frag from other frags. always use 2 as
first entry's offset.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

we never add snapdir and the hidden .ceph dir into readdir cache
Signed-off-by: NYan, Zheng <zyan@redhat.com>

use binary search to find cache index that corresponds to readdir
postion.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Setxattr with NULL value and XATTR_REPLACE flag should be equivalent
to removexattr. But current MDS does not support deleting vxattrs through
MDS_OP_SETXATTR request. The workaround is sending MDS_OP_RMXATTR request
if setxattr actually removs xattr.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Signed-off-by: NYan, Zheng <zyan@redhat.com>

symlink target is useless for debug and can be very long. It's annoying
to show it in debugfs/mdsc.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

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: NYan, Zheng <zyan@redhat.com>

When mds session gets killed, read/write operation may hang.
Client waits for Frw caps, but mds does not know what caps client
wants. To recover this, client sends an open request to mds. The
request will tell mds what caps client wants.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Signed-off-by: NYan, Zheng <zyan@redhat.com>

To access non-default filesystem, we just need to subscribe to
mdsmap.<MDS_NAMESPACE_ID> and add a new mount option for mds
namespace id.
Signed-off-by: NYan, Zheng <zyan@redhat.com>
[idryomov@gmail.com: switch to a new libceph API]
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

... with a wrapper around maybe_request_map() - no need for two
osdmap-specific functions.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

There is now about a dozen CEPH_OSDMAP_* flags.  This is a debugging
interface, so just dump in hex instead of spelling each flag out.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

This adds the "map check" infrastructure for sending osdmap version
checks on CALC_TARGET_POOL_DNE and completing in-flight requests with
-ENOENT if the target pool doesn't exist or has just been deleted.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

For map check, we are going to need to send CEPH_MSG_MON_GET_VERSION
messages asynchronously and get a callback on completion.  Refactor MON
client to allow firing off generic requests asynchronously and add an
async variant of ceph_monc_get_version().  ceph_monc_do_statfs() is
switched over and remains sync.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Implement ceph_osdc_watch_check() to be able to check on status of
watch.  Note that the time it takes for a watch/notify event to get
delivered through the notify_wq is taken into account.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Implement ceph_osdc_notify() for sending notifies.

Due to the fact that the current messenger can't do read-in into
pagelists (it can only do write-out from them), I had to go with a page
vector for a NOTIFY_COMPLETE payload, for now.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

This adds support and switches rbd to a new, more reliable version of
watch/notify protocol.  As with the OSD client update, this is mostly
about getting the right structures linked into the right places so that
reconnects are properly sent when needed.  watch/notify v2 also
requires sending regular pings to the OSDs - send_linger_ping().

A major change from the old watch/notify implementation is the
introduction of ceph_osd_linger_request - linger requests no longer
piggy back on ceph_osd_request.  ceph_osd_event has been merged into
ceph_osd_linger_request.

All the details are now hidden within libceph, the interface consists
of a simple pair of watch/unwatch functions and ceph_osdc_notify_ack().
ceph_osdc_watch() does return ceph_osd_linger_request, but only to keep
the lifetime management simple.

ceph_osdc_notify_ack() accepts an optional data payload, which is
relayed back to the notifier.

Portions of this patch are loosely based on work by Douglas Fuller
<dfuller@redhat.com> and Mike Christie <michaelc@cs.wisc.edu>.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Introduce __rbd_dev_header_unwatch_sync(), which doesn't flush notify
callbacks.  This is for the new rados_watcherrcb_t, which would be
called from a notify callback.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

The unwatch timeout is currently implemented in rbd.  With
watch/unwatch code moving into libceph, we are going to need
a ceph_osdc_wait_request() variant with a timeout.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

These are going to be used by request_reinit() code.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>