Define and use functions that encapsulate the initializion of a
ceph_osd_data structure.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Hold off building the osd request message in ceph_writepages_start()
until just before it will be submitted to the osd client for
execution.

We'll still create the request and allocate the page pointer array
after we learn we have at least one page to write.  A local variable
will be used to keep track of the allocated array of pages.  Wait
until just before submitting the request for assigning that page
array pointer to the request message.

Create ands use a new function osd_req_op_extent_update() whose
purpose is to serve this one spot where the length value supplied
when an osd request's op was initially formatted might need to get
changed (reduced, never increased) before submitting the request.

Previously, ceph_writepages_start() assigned the message header's
data length because of this update.  That's no longer necessary,
because ceph_osdc_build_request() will recalculate the right
value to use based on the content of the ops in the request.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Defer building the osd request until just before submitting it in
all callers except ceph_writepages_start().  (That caller will be
handed in the next patch.)
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

There is a helper function alloc_page_vec() that, despite its
generic sounding name depends heavily on an osd request structure
being populated with certain information.

There is only one place this function is used, and it ends up
being a bit simpler to just open code what it does, so get
rid of the helper.

The real motivation for this is deferring building the of the osd
request message, and this is a step in that direction.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Mostly for readability, define ceph_writepages_osd_request() and
use it to allocate the osd request for ceph_writepages_start().
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

This patch moves the call to ceph_osdc_build_request() out of
ceph_osdc_new_request() and into its caller.

This is in order to defer formatting osd operation information into
the request message until just before request is started.

The only unusual (ab)user of ceph_osdc_build_request() is
ceph_writepages_start(), where the final length of write request may
change (downward) based on the current inode size or the oldest
snapshot context with dirty data for the inode.

The remaining callers don't change anything in the request after has
been built.

This means the ops array is now supplied by the caller.  It also
means there is no need to pass the mtime to ceph_osdc_new_request()
(it gets provided to ceph_osdc_build_request()).  And rather than
passing a do_sync flag, have the number of ops in the ops array
supplied imply adding a second STARTSYNC operation after the READ or
WRITE requested.

This and some of the patches that follow are related to having the
messenger (only) be responsible for filling the content of the
message header, as described here:
    http://tracker.ceph.com/issues/4589Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

There's one spot in ceph_writepages_start() that open-codes what
page_offset() does safely.  Use the macro so we don't have to worry
about wrapping.

This resolves:
    http://tracker.ceph.com/issues/4648Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

In create_fs_client() a memory pool is set up be used for arrays of
pages that might be needed in ceph_writepages_start() if memory is
tight.  There are two problems with the way it's initialized:
    - The size provided is the number of pages we want in the
      array, but it should be the number of bytes required for
      that many page pointers.
    - The number of pages computed can end up being 0, while we
      will always need at least one page.

This patch fixes both of these problems.

This resolves the two simple problems defined in:
    http://tracker.ceph.com/issues/4603Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Use wrapper functions that check whether the auth op exists so that callers
do not need a bunch of conditional checks.  Simplifies the external
interface.
Signed-off-by: NSage Weil <sage@inktank.com>
Reviewed-by: NAlex Elder <elder@inktank.com>

Currently the messenger calls out to a get_authorizer con op, which will
create a new authorizer if it doesn't yet have one.  In the meantime, when
we rotate our service keys, the authorizer doesn't get updated.  Eventually
it will be rejected by the server on a new connection attempt and get
invalidated, and we will then rebuild a new authorizer, but this is not
ideal.

Instead, if we do have an authorizer, call a new update_authorizer op that
will verify that the current authorizer is using the latest secret.  If it
is not, we will build a new one that does.  This avoids the transient
failure.

This fixes one of the sorry sequence of events for bug

	http://tracker.ceph.com/issues/4282Signed-off-by: NSage Weil <sage@inktank.com>
Reviewed-by: NAlex Elder <elder@inktank.com>

We should advance the user data pointer by _len_ instead of _written_.
_len_ is the data length written in each iteration while _written_ is the
accumulated data length we have writtent out.
Signed-off-by: NHenry C Chang <henry.cy.chang@gmail.com>
Reviewed-by: NGreg Farnum <greg@inktank.com>
Tested-by: NSage Weil <sage@inktank.com>

Current ceph code tracks directory's completeness in two places.
ceph_readdir() checks i_release_count to decide if it can set the
I_COMPLETE flag in i_ceph_flags. All other places check the I_COMPLETE
flag. This indirection introduces locking complexity.

This patch adds a new variable i_complete_count to ceph_inode_info.
Set i_release_count's value to it when marking a directory complete.
By comparing the two variables, we know if a directory is complete
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>

Change it so we only assign outgoing data information for messages
if there is outgoing data to send.

This then allows us to add a few more (currently commented-out)
assertions.

This is related to:
    http://tracker.ceph.com/issues/4284Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NGreg Farnum <greg@inktank.com>

Define ceph_msg_data_set_pagelist(), ceph_msg_data_set_bio(), and
ceph_msg_data_set_trail() to clearly abstract the assignment of the
remaining data-related fields in a ceph message structure.  Use the
new functions in the osd client and mds client.

This partially resolves:
    http://tracker.ceph.com/issues/4263Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

When setting page array information for message data, provide the
byte length rather than the page count ceph_msg_data_set_pages().
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Define a function ceph_msg_data_set_pages(), which more clearly
abstracts the assignment page-related fields for data in a ceph
message structure.  Use this new function in the osd client and mds
client.

Ideally, these fields would never be set more than once (with
BUG_ON() calls to guarantee that).  At the moment though the osd
client sets these every time it receives a message, and in the event
of a communication problem this can happen more than once.  (This
will be resolved shortly, but setting up these helpers first makes
it all a bit easier to work with.)

Rearrange the field order in a ceph_msg structure to group those
that are used to define the possible data payloads.

This partially resolves:
    http://tracker.ceph.com/issues/4263Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Record the byte count for an osd request rather than the page count.
The number of pages can always be derived from the byte count (and
alignment/offset) but the reverse is not true.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

An osd request defines information about where data to be read
should be placed as well as where data to write comes from.
Currently these are represented by common fields.

Keep information about data for writing separate from data to be
read by splitting these into data_in and data_out fields.

This is the key patch in this whole series, in that it actually
identifies which osd requests generate outgoing data and which
generate incoming data.  It's less obvious (currently) that an osd
CALL op generates both outgoing and incoming data; that's the focus
of some upcoming work.

This resolves:
    http://tracker.ceph.com/issues/4127Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

An osd request uses either pages or a bio list for its data.  Use a
union to record information about the two, and add a data type
tag to select between them.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Pull the fields in an osd request structure that define the data for
the request out into a separate structure.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Currently ceph_osdc_new_request() assigns an osd request's
r_num_pages and r_alignment fields.  The only thing it does
after that is call ceph_osdc_build_request(), and that doesn't
need those fields to be assigned.

Move the assignment of those fields out of ceph_osdc_new_request()
and into its caller.  As a result, the page_align parameter is no
longer used, so get rid of it.

Note that in ceph_sync_write(), the value for req->r_num_pages had
already been calculated earlier (as num_pages, and fortunately
it was computed the same way).  So don't bother recomputing it,
but because it's not needed earlier, move that calculation after the
call to ceph_osdc_new_request().  Hold off making the assignment to
r_alignment, doing it instead r_pages and r_num_pages are
getting set.

Similarly, in start_read(), nr_pages already holds the number of
pages in the array (and is calculated the same way), so there's no
need to recompute it.  Move the assignment of the page alignment
down with the others there as well.

This and the next few patches are preparation work for:
    http://tracker.ceph.com/issues/4127Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

(This is being reposted.  The first one had a problem because it
erroneously added a similar change elsewhere; that change has been
dropped.)

The next patch in this series points out that the calculation for
the number of pages in an osd request is getting done twice.  It
is not obvious, but the result of both calculations is identical.
This patch simplifies one of them--as a separate step--to make
it clear that the transformation in the next patch is valid.

In ceph_sync_write() there is some magic that computes page_align
for an osd request.  But a little analysis shows it can be
simplified.

First, we have:
 	io_align = pos & ~PAGE_MASK;
which is used here:
	page_align = (pos - io_align + buf_align) & ~PAGE_MASK;

Note (pos - io_align) simply rounds "pos" down to the nearest multiple
of the page size.

We also have:
 	buf_align = (unsigned long)data & ~PAGE_MASK;

Adding buf_align to that rounded-down "pos" value will stay within
the same page; the result will just be offset by the page offset for
the "data" pointer.  The final mask therefore leaves just the value
of "buf_align".

One more simplification.  Note that the result of calc_pages_for()
is invariant of which page the offset starts in--the only thing that
matters is the offset within the starting page.  We will have
put the proper page offset to use into "page_align", so just use
that in calculating num_pages.

This resolves:
    http://tracker.ceph.com/issues/4166Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

There's a spot that computes the number of pages to allocate for a
page-aligned length by just shifting it.  Use calc_pages_for()
instead, to be consistent with usage everywhere else.  The result
is the same.

The reason for this is to make it clearer in an upcoming patch that
this calculation is duplicated.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Currently, incoming mds messages never use page data, which means
there is no need to set the page_alignment field in the message.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NGreg Farnum <greg@inktank.com>

The only user of the ceph messenger that doesn't define an alloc_msg
method is the mds client.  Define one, such that it works just like
it did before, and simplify ceph_con_in_msg_alloc() by assuming the
alloc_msg method is always present.

This and the next patch resolve:
    http://tracker.ceph.com/issues/4322Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NGreg Farnum <greg@inktank.com>

The purpose of ceph_calc_object_layout() is to fill in the pool
number and seed for a ceph_pg structure provided, based on a given
osd map and target object id.

Currently that function takes a file layout parameter, but the only
thing used out of that is its pool number.

Change the function so it takes a pool number rather than the full
file layout structure.  Only update the ceph_pg if the pool is found
in the osd map.  Get rid of few useless lines of code from the
function while there.

Since the function now very clearly just fills in the ceph_pg
structure it's provided, rename it ceph_calc_ceph_pg().
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

The pagelist_count field is never actually used, so get rid of it.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

make __ceph_do_pending_vmtruncate() acquire the i_mutex if the caller
does not hold the i_mutex, so ceph_aio_read() can call safely.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NGreg Farnum <greg@inktank.com>

ceph_aio_write() has an optimization that marks CEPH_CAP_FILE_WR
cap dirty before data is copied to page cache and inode size is
updated. The optimization avoids slow cap revocation caused by
balance_dirty_pages(), but introduces inode size update race. If
ceph_check_caps() flushes the dirty cap before the inode size is
updated, MDS can miss the new inode size. So just remove the
optimization.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NGreg Farnum <greg@inktank.com>

commit 22cddde1 breaks the atomicity of write operation, it also
introduces a deadlock between write and truncate.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NGreg Farnum <greg@inktank.com>

Conflicts:
	fs/ceph/addr.c

commit c6ffe100 moved the flag that tracks if the dcache contents
for a directory are complete to dentry. The problem is there are
lots of places that use ceph_dir_{set,clear,test}_complete() while
holding i_ceph_lock. but ceph_dir_{set,clear,test}_complete() may
sleep because they call dput().

This patch basically reverts that commit. For ceph_d_prune(), it's
called with both the dentry to prune and the parent dentry are
locked. So it's safe to access the parent dentry's d_inode and
clear I_COMPLETE flag.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NGreg Farnum <greg@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

MDS ignores cap update message if migrate_seq mismatch, so when
receiving a cap import message with higher migrate_seq, set mds_want
according to the cap import message.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NGreg Farnum <greg@inktank.com>

So the client will later send cap release message to MDS
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NGreg Farnum <greg@inktank.com>

commit 6e8575fa makes parse_reply_info_extra() return -EIO for LSSNAP
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NGreg Farnum <greg@inktank.com>

Use distinct fields for tracking the number of pages in a message's
page array and in a message's page list.  Currently only one or the
other is used at a time, but that will be changing soon.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.

A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.

Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.

Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives.  Allowing simple, safe,
well understood work-arounds to known problematic software.

This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work.  While writing this patch I saw a handful of such
cases.  The most significant being autofs that lives in the module
autofs4.

This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.

After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module.  The common pattern in the kernel is to call request_module()
without regards to the users permissions.  In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted.  In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Acked-by: NKees Cook <keescook@chromium.org>
Reported-by: NKees Cook <keescook@google.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

Use the new version of the encoding for osd requests and replies.  In the
process, update the way we are tracking request ops and reply lengths and
results in the struct ceph_osd_request.  Update the rbd and fs/ceph users
appropriately.

The main changes are:
 - we keep pointers into the request memory for fields we need to update
   each time the request is sent out over the wire
 - we keep information about the result in an array in the request struct
   where the users can easily get at it.
Signed-off-by: NSage Weil <sage@inktank.com>
Reviewed-by: NAlex Elder <elder@inktank.com>

Instead of using the old ceph_object_layout struct, update our internal
ceph_calc_object_layout method to use the ceph_pg type.  This allows us to
pass the full 32-bit precision of the pgid.seed to the callers.  It also
allows some callers to avoid reaching into the request structures for the
struct ceph_object_layout fields.
Signed-off-by: NSage Weil <sage@inktank.com>
Reviewed-by: NAlex Elder <elder@inktank.com>

Support (and require) the PGID64, PGPOOL3, and OSDENC protocol features.
These have been present in ceph.git since v0.42, Feb 2012.  Require these
features to simplify support; nobody is running older userspace.

Note that the new request and reply encoding is still not in place, so the new
code is not yet functional.
Signed-off-by: NSage Weil <sage@inktank.com>
Reviewed-by: NAlex Elder <elder@inktank.com>

Always decode data into our cpu-native ceph_pg type that has the correct
field widths.  Limit any remaining uses of ceph_pg_v1 to dealing with the
legacy protocol.
Signed-off-by: NSage Weil <sage@inktank.com>
Reviewed-by: NAlex Elder <elder@inktank.com>