Previously our dcache readdir code relies on that child dentries in
directory dentry's d_subdir list are sorted by dentry's offset in
descending order. When adding dentries to the dcache, if a dentry
already exists, our readdir code moves it to head of directory
dentry's d_subdir list. This design relies on dcache internals.
Al Viro suggests using ncpfs's approach: keeping array of pointers
to dentries in page cache of directory inode. the validity of those
pointers are presented by directory inode's complete and ordered
flags. When a dentry gets pruned, we clear directory inode's complete
flag in the d_prune() callback. Before moving a dentry to other
directory, we clear the ordered flag for both old and new directory.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

GFP_NOFS memory allocation is required for page writeback path.
But there is no need to use GFP_NOFS in syscall path and readpage
path
Signed-off-by: NYan, Zheng <zyan@redhat.com>

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

if flushing caps were revoked, we should re-send the cap flush in
client reconnect stage. This guarantees that MDS processes the cap
flush message before issuing the flushing caps to other client.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

According to this information, MDS can trim its completed caps flush
list (which is used to detect duplicated cap flush).
Signed-off-by: NYan, Zheng <zyan@redhat.com>

So we know TID of the oldest pending caps flushing. Later patch will
send this information to MDS, so that MDS can trim its completed caps
flush list.

Tracking pending caps flushing globally also simplifies syncfs code.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Previously we do not trace accurate TID for flushing caps. when
MDS failovers, we have no choice but to re-send all flushing caps
with a new TID. This can cause problem because MDS can has already
flushed some caps and has issued the same caps to other client.
The re-sent cap flush has a new TID, which makes MDS unable to
detect if it has already processed the cap flush.

This patch adds code to track pending caps flushing accurately.
When re-sending cap flush is needed, we use its original flush
TID.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

fsync() on directory should flush dirty caps and wait for any
uncommitted directory opertions to commit. But ceph_dir_fsync()
only waits for uncommitted directory opertions.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Current ceph_fsync() only flushes dirty caps and wait for them to be
flushed. It doesn't wait for caps that has already been flushing.
This patch makes ceph_fsync() wait for pending flushing caps too.
Besides, this patch also makes caps_are_flushed() peroperly handle
tid wrapping.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

when copying files to cephfs, file data may stay in page cache after
corresponding file is closed. Cached data use Fc capability. If we
include Fc capability in cap_wanted, MDS will treat files with cached
data as open files, and journal them in an EOpen event when trimming
log segment.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

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

No need to bifurcate wait now that we've got ceph_timeout_jiffies().
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NAlex Elder <elder@linaro.org>
Reviewed-by: NYan, Zheng <zyan@redhat.com>

There are currently three libceph-level timeouts that the user can
specify on mount: mount_timeout, osd_idle_ttl and osdkeepalive.  All of
these are in seconds and no checking is done on user input: negative
values are accepted, we multiply them all by HZ which may or may not
overflow, arbitrarily large jiffies then get added together, etc.

There is also a bug in the way mount_timeout=0 is handled.  It's
supposed to mean "infinite timeout", but that's not how wait.h APIs
treat it and so __ceph_open_session() for example will busy loop
without much chance of being interrupted if none of ceph-mons are
there.

Fix all this by verifying user input, storing timeouts capped by
msecs_to_jiffies() in jiffies and using the new ceph_timeout_jiffies()
helper for all user-specified waits to handle infinite timeouts
correctly.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NAlex Elder <elder@linaro.org>

setfilelock requests can block for a long time, which can prevent
client from advancing its oldest tid.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Previously we pre-allocate cap release messages for each caps. This
wastes lots of memory when there are large amount of caps. This patch
make the code not pre-allocate the cap release messages. Instead,
we add the corresponding ceph_cap struct to a list when releasing a
cap. Later when flush cap releases is needed, we allocate the cap
release messages dynamically.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

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

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

When ceph inode's i_head_snapc is NULL, __ceph_mark_dirty_caps()
accesses snap realm's cached_context. So we need take read lock
of snap_rwsem.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

when a snap notification contains no new snapshot, we can avoid
sending FLUSHSNAP message to MDS. But we still need to create
cap_snap in some case because it's required by write path and
page writeback path
Signed-off-by: NYan, Zheng <zyan@redhat.com>

In most cases that snap context is needed, we are holding
reference of CEPH_CAP_FILE_WR. So we can set ceph inode's
i_head_snapc when getting the CEPH_CAP_FILE_WR reference,
and make codes get snap context from i_head_snapc. This makes
the code simpler.

Another benefit of this change is that we can handle snap
notification more elegantly. Especially when snap context
is updated while someone else is doing write. The old queue
cap_snap code may set cap_snap's context to ether the old
context or the new snap context, depending on if i_head_snapc
is set. The new queue capp_snap code always set cap_snap's
context to the old snap context.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Cached_context in ceph_snap_realm is directly accessed by
uninline_data() and get_pool_perm(). This is racy in theory.
both uninline_data() and get_pool_perm() do not modify existing
object, they only create new object. So we can pass the empty
snap context to them.  Unlike cached_context in ceph_snap_realm,
we do not need to protect the empty snap context.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

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

Signed-off-by: NYan, Zheng <zyan@redhat.com>
Reviewed-by: NAlex Elder <elder@linaro.org>

For CEPH_OSD_CMPXATTR_MODE_U64, OSD expects the u64 to be encoded
as string in object's xattr.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

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

sb->s_root can be null when umounting
Signed-off-by: NYan, Zheng <zyan@redhat.com>

If a directory is complete, we want to keep the exclusive
cap. So that MDS does not end up revoking the shared cap
on every create/unlink operation.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Don't pollute /proc/mounts with default options (presently these are
dcache, nofsc and acl).  Leave the acl/noacl however - it's a bit of
a special case due to CONFIG_CEPH_FS_POSIX_ACL.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Split ceph_show_options() into two pieces and move the piece
responsible for printing client (libceph) options into net/ceph.  This
way people adding a libceph option wouldn't have to remember to update
code in fs/ceph.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

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

remove_session_caps_cb() does not truncate dirty data in page
cache, but zeros i_wrbuffer_ref/i_wrbuffer_ref_head. This will
result negtive i_wrbuffer_ref/i_wrbuffer_ref_head
Signed-off-by: NYan, Zheng <zyan@redhat.com>

No i_auth_cap means reconnecting to MDS was denied. So don't
add new dirty caps.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

when reconnecting to MDS is denied, we remove session caps
forcibly. But it's possible there are ongoing write, the
write code needs to reference i_snap_realm. So if there are
ongoing write, we keep i_snap_realm.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Currently, there is no check for the kstrdup() for r_path2,
r_path1 and snapdir_name as various locations as there is a
possibility of failure during memory pressure. Therefore,
returning ENOMEM where the checks have been missed.
Signed-off-by: NSanidhya Kashyap <sanidhya.gatech@gmail.com>
Signed-off-by: NYan, Zheng <zyan@redhat.com>

When ceph_update_writeable_page fails (including -EAGAIN), it
unlocks (w/ unlock_page) the page but does not 'release'
(w/ page_cache_release) properly.

Upon error, properly set *pagep to NULL, indicating an error.
Signed-off-by: NTaesoo Kim <tsgatesv@gmail.com>
Signed-off-by: NYan, Zheng <zyan@redhat.com>

return type of wait_for_completion_timeout is unsigned long not int. An
appropriately named unsigned long is added and the assignment fixed up.
Signed-off-by: NNicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: NYan, Zheng <zyan@redhat.com>

This is only an API consolidation and should make things more readable
it replaces var * HZ / 1000 by msecs_to_jiffies(var).
Signed-off-by: NNicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: NYan, Zheng <zyan@redhat.com>

ceph_aops was already defined extern in addr.c section
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NYan, Zheng <zyan@redhat.com>

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

These cap releases are stale because MDS will re-establish client
caps according to the cap reconnect messages.

Note: MDS can detect stale cap messages, so these stale cap
releases are harmless even we don't drop them.
Signed-off-by: NYan, Zheng <zyan@redhat.com>