Commit Graph

112 Commits

Author SHA1 Message Date
Yan, Zheng
37505d5768 ceph: take i_mutex before getting Fw cap
There is deadlock as illustrated bellow. The fix is taking i_mutex
before getting Fw cap reference.

      write                    truncate                 MDS
---------------------     --------------------      --------------
get Fw cap
                          lock i_mutex
lock i_mutex (blocked)
                          request setattr.size  ->
                                                <-   revoke Fw cap

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-05-01 21:18:53 -07:00
Yan, Zheng
2f276c5111 ceph: use i_release_count to indicate dir's completeness
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: Yan, Zheng <zheng.z.yan@intel.com>
2013-05-01 21:17:07 -07:00
Yan, Zheng
a8673d61ad ceph: use I_COMPLETE inode flag instead of D_COMPLETE flag
commit c6ffe10015 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: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-05-01 21:14:33 -07:00
Yan, Zheng
964266cce9 ceph: set mds_want according to cap import message
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: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
2013-05-01 21:14:32 -07:00
Yan, Zheng
d40ee0dcc1 ceph: queue cap release when trimming cap
So the client will later send cap release message to MDS

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
2013-05-01 21:14:31 -07:00
Linus Torvalds
1cf0209c43 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
Pull Ceph updates from Sage Weil:
 "A few groups of patches here.  Alex has been hard at work improving
  the RBD code, layout groundwork for understanding the new formats and
  doing layering.  Most of the infrastructure is now in place for the
  final bits that will come with the next window.

  There are a few changes to the data layout.  Jim Schutt's patch fixes
  some non-ideal CRUSH behavior, and a set of patches from me updates
  the client to speak a newer version of the protocol and implement an
  improved hashing strategy across storage nodes (when the server side
  supports it too).

  A pair of patches from Sam Lang fix the atomicity of open+create
  operations.  Several patches from Yan, Zheng fix various mds/client
  issues that turned up during multi-mds torture tests.

  A final set of patches expose file layouts via virtual xattrs, and
  allow the policies to be set on directories via xattrs as well
  (avoiding the awkward ioctl interface and providing a consistent
  interface for both kernel mount and ceph-fuse users)."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (143 commits)
  libceph: add support for HASHPSPOOL pool flag
  libceph: update osd request/reply encoding
  libceph: calculate placement based on the internal data types
  ceph: update support for PGID64, PGPOOL3, OSDENC protocol features
  ceph: update "ceph_features.h"
  libceph: decode into cpu-native ceph_pg type
  libceph: rename ceph_pg -> ceph_pg_v1
  rbd: pass length, not op for osd completions
  rbd: move rbd_osd_trivial_callback()
  libceph: use a do..while loop in con_work()
  libceph: use a flag to indicate a fault has occurred
  libceph: separate non-locked fault handling
  libceph: encapsulate connection backoff
  libceph: eliminate sparse warnings
  ceph: eliminate sparse warnings in fs code
  rbd: eliminate sparse warnings
  libceph: define connection flag helpers
  rbd: normalize dout() calls
  rbd: barriers are hard
  rbd: ignore zero-length requests
  ...
2013-02-28 17:43:09 -08:00
Eric W. Biederman
bd2bae6a66 ceph: Convert kuids and kgids before printing them.
Before printing kuid and kgids values convert them into
the initial user namespace.

Cc: Sage Weil <sage@inktank.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-02-12 03:19:27 -08:00
Eric W. Biederman
05cb11c17e ceph: Translate between uid and gids in cap messages and kuids and kgids
- Make the uid and gid arguments of send_cap_msg() used to compose
  ceph_mds_caps messages of type kuid_t and kgid_t.

- Pass inode->i_uid and inode->i_gid in __send_cap to send_cap_msg()
  through variables of type kuid_t and kgid_t.

- Modify struct ceph_cap_snap to store uids and gids in types kuid_t
  and kgid_t.  This allows capturing inode->i_uid and inode->i_gid in
  ceph_queue_cap_snap() without loss and pssing them to
  __ceph_flush_snaps() where they are removed from struct
  ceph_cap_snap and passed to send_cap_msg().

- In handle_cap_grant translate uid and gids in the initial user
  namespace stored in struct ceph_mds_cap into kuids and kgids
  before setting inode->i_uid and inode->i_gid.

Cc: Sage Weil <sage@inktank.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-02-12 03:19:24 -08:00
Yan, Zheng
390306c38d ceph: check mds_wanted for imported cap
The MDS may have incorrect wanted caps after importing caps. So the
client should check the value mds has and send cap update if necessary.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-01-17 12:42:38 -06:00
Yan, Zheng
66f58691c5 ceph: allocate cap_release message when receiving cap import
When client wants to release an imported cap, it's possible there
is no reserved cap_release message in corresponding mds session.
so __queue_cap_release causes kernel panic.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-01-17 12:42:38 -06:00
Yan, Zheng
395c312b9c ceph: allow revoking duplicated caps issued by non-auth MDS
Allow revoking duplicated caps issued by non-auth MDS if these caps
are also issued by auth MDS.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-01-17 12:42:38 -06:00
Yan, Zheng
8a92a119b2 ceph: move dirty inode to migrating list when clearing auth caps
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-01-17 12:42:37 -06:00
Yan, Zheng
0e5e1774a9 ceph: call handle_cap_grant() for cap import message
If client sends cap message that requests new max size during
exporting caps, the exporting MDS will drop the message quietly.
So the client may wait for the reply that updates the max size
forever. call handle_cap_grant() for cap import message can
avoid this issue.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-12-13 08:13:08 -06:00
Yan, Zheng
0685235ffd ceph: Don't add dirty inode to dirty list if caps is in migration
Add dirty inode to cap_dirty_migrating list instead, this can avoid
ceph_flush_dirty_caps() entering infinite loop.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-12-13 08:13:08 -06:00
Yan, Zheng
5e62ad3015 ceph: Don't update i_max_size when handling non-auth cap
The cap from non-auth mds doesn't have a meaningful max_size value.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-12-13 08:13:07 -06:00
Yan, Zheng
4d1d0534f5 ceph: Hold caps_list_lock when adjusting caps_{use, total}_count
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-11-04 03:08:24 -08:00
Wei Yongjun
b905a7f8b7 ceph: convert to use le32_add_cpu()
Convert cpu_to_le32(le32_to_cpu(E1) + E2) to use le32_add_cpu().

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-10-01 14:30:54 -05:00
Linus Torvalds
6c073a7ee2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: fix safety of rbd_put_client()
  rbd: fix a memory leak in rbd_get_client()
  ceph: create a new session lock to avoid lock inversion
  ceph: fix length validation in parse_reply_info()
  ceph: initialize client debugfs outside of monc->mutex
  ceph: change "ceph.layout" xattr to be "ceph.file.layout"
2012-02-02 15:47:33 -08:00
Alex Elder
d8fb02abdc ceph: create a new session lock to avoid lock inversion
Lockdep was reporting a possible circular lock dependency in
dentry_lease_is_valid().  That function needs to sample the
session's s_cap_gen and and s_cap_ttl fields coherently, but needs
to do so while holding a dentry lock.  The s_cap_lock field was
being used to protect the two fields, but that can't be taken while
holding a lock on a dentry within the session.

In most cases, the s_cap_gen and s_cap_ttl fields only get operated
on separately.  But in three cases they need to be updated together.
Implement a new lock to protect the spots updating both fields
atomically is required.

Signed-off-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Sage Weil <sage@newdream.net>
2012-02-02 12:49:19 -08:00
Al Viro
5706b27dea ceph: propagate umode_t
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:55:16 -05:00
Sage Weil
be655596b3 ceph: use i_ceph_lock instead of i_lock
We have been using i_lock to protect all kinds of data structures in the
ceph_inode_info struct, including lists of inodes that we need to iterate
over while avoiding races with inode destruction.  That requires grabbing
a reference to the inode with the list lock protected, but igrab() now
takes i_lock to check the inode flags.

Changing the list lock ordering would be a painful process.

However, using a ceph-specific i_ceph_lock in the ceph inode instead of
i_lock is a simple mechanical change and avoids the ordering constraints
imposed by igrab().

Reported-by: Amon Ott <a.ott@m-privacy.de>
Signed-off-by: Sage Weil <sage@newdream.net>
2011-12-07 10:46:44 -08:00
Sage Weil
c6ffe10015 ceph: use new D_COMPLETE dentry flag
We used to use a flag on the directory inode to track whether the dcache
contents for a directory were a complete cached copy.  Switch to a dentry
flag CEPH_D_COMPLETE that is safely updated by ->d_prune().

Signed-off-by: Sage Weil <sage@newdream.net>
2011-11-05 21:10:10 -07:00
Miklos Szeredi
bfe8684869 filesystems: add set_nlink()
Replace remaining direct i_nlink updates with a new set_nlink()
updater function.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2011-11-02 12:53:43 +01:00
Sage Weil
b61c27636f libceph: don't complain on msgpool alloc failures
The pool allocation failures are masked by the pool; there is no need to
spam the console about them.  (That's the whole point of having the pool
in the first place.)

Mark msg allocations whose failure is safely handled as such.

Signed-off-by: Sage Weil <sage@newdream.net>
2011-10-25 16:10:15 -07:00
Josef Bacik
02c24a8218 fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers
Btrfs needs to be able to control how filemap_write_and_wait_range() is called
in fsync to make it less of a painful operation, so push down taking i_mutex and
the calling of filemap_write_and_wait() down into the ->fsync() handlers.  Some
file systems can drop taking the i_mutex altogether it seems, like ext3 and
ocfs2.  For correctness sake I just pushed everything down in all cases to make
sure that we keep the current behavior the same for everybody, and then each
individual fs maintainer can make up their mind about what to do from there.
Thanks,

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:59 -04:00
Sage Weil
70b666c3b4 ceph: use ihold when we already have an inode ref
We should use ihold whenever we already have a stable inode ref, even
when we aren't holding i_lock.  This avoids adding new and unnecessary
locking dependencies.

Signed-off-by: Sage Weil <sage@newdream.net>
2011-06-07 21:34:11 -07:00
Sage Weil
db3540522e ceph: fix cap flush race reentrancy
In e9964c10 we change cap flushing to do a delicate dance because some
inodes on the cap_dirty list could be in a migrating state (got EXPORT but
not IMPORT) in which we couldn't actually flush and move from
dirty->flushing, breaking the while (!empty) { process first } loop
structure.  It worked for a single sync thread, but was not reentrant and
triggered infinite loops when multiple syncers came along.

Instead, move inodes with dirty to a separate cap_dirty_migrating list
when in the limbo export-but-no-import state, allowing us to go back to
the simple loop structure (which was reentrant).  This is cleaner and more
robust.

Audited the cap_dirty users and this looks fine:
list_empty(&ci->i_dirty_item) is still a reliable indicator of whether we
have dirty caps (which list we're on is irrelevant) and list_del_init()
calls still do the right thing.

Signed-off-by: Sage Weil <sage@newdream.net>
2011-05-24 11:52:12 -07:00
Sage Weil
3540303f87 ceph: fix rare potential cap leak
If we grab new_cap, retake the lock, and find we already have a cap now
for the given mds, release new_cap.

Signed-off-by: Sage Weil <sage@newdream.net>
2011-05-19 11:25:03 -07:00
Henry C Chang
d3d0720d4a ceph: do not use i_wrbuffer_ref as refcount for Fb cap
We increments i_wrbuffer_ref when taking the Fb cap. This breaks
the dirty page accounting and causes looping in
__ceph_do_pending_vmtruncate, and ceph client hangs.

This bug can be reproduced occasionally by running blogbench.

Add a new field i_wb_ref to inode and dedicate it to Fb reference
counting.

Signed-off-by: Henry C Chang <henry.cy.chang@gmail.com>
Signed-off-by: Sage Weil <sage@newdream.net>
2011-05-11 10:44:48 -07:00
Sage Weil
fca65b4ad7 ceph: do not call __mark_dirty_inode under i_lock
The __mark_dirty_inode helper now takes i_lock as of 250df6ed.  Fix the
one ceph callers that held i_lock (__ceph_mark_dirty_caps) to return the
flags value so that the callers can do it outside of i_lock.

Signed-off-by: Sage Weil <sage@newdream.net>
2011-05-04 12:56:45 -07:00
Sage Weil
3772d26d87 ceph: use ihold() when i_lock is held
See 0444d76ae6.

Signed-off-by: Sage Weil <sage@newdream.net>
2011-05-03 09:28:08 -07:00
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Sage Weil
7e57b81c76 ceph: avoid immediate cap check after import
The NODELAY flag avoids the heuristics that delay cap (issued/wanted)
release.  There's no reason for that after we import a cap, and it kills
whatever benefit we get from those delays.

Signed-off-by: Sage Weil <sage@newdream.net>
2011-01-19 09:23:26 -08:00
Sage Weil
088b3f5e9e ceph: fix flushing of caps vs cap import
If we are mid-flush and a cap is migrated to another node, we need to
resend the cap flush message to the new MDS, and do so with the original
flush_seq to avoid leaking across a sync boundary.  Previously we didn't
redo the flush (we only flushed newly dirty data), which would cause a
later sync to hang forever.

Signed-off-by: Sage Weil <sage@newdream.net>
2011-01-19 09:23:25 -08:00
Sage Weil
24be0c4810 ceph: fix erroneous cap flush to non-auth mds
The int flushing is global and not clear on each iteration of the loop,
which can cause a second flush of caps to any MDSs with ids greater than
the auth.

Signed-off-by: Sage Weil <sage@newdream.net>
2011-01-19 09:23:24 -08:00
Sage Weil
cd045cb42a ceph: fix rdcache_gen usage and invalidate
We used to use rdcache_gen to indicate whether we "might" have cached
pages.  Now we just look at the mapping to determine that.  However, some
old behavior remains from that transition.

First, rdcache_gen == 0 no longer means we have no pages.  That can happen
at any time (presumably when we carry FILE_CACHE).  We should not reset it
to zero, and we should not check that it is zero.

That means that the only purpose for rdcache_revoking is to resolve races
between new issues of FILE_CACHE and an async invalidate.  If they are
equal, we should invalidate.  On success, we decrement rdcache_revoking,
so that it is no longer equal to rdcache_gen.  Similarly, if we success
in doing a sync invalidate, set revoking = gen - 1.  (This is a small
optimization to avoid doing unnecessary invalidate work and does not
affect correctness.)

Signed-off-by: Sage Weil <sage@newdream.net>
2010-11-08 07:29:05 -08:00
Sage Weil
feb4cc9bb4 ceph: re-request max_size if cap auth changes
If the auth cap migrates to another MDS, clear requested_max_size so that
we resend any pending max_size increase requests.  This fixes potential
hangs on writes that extend a file and race with an cap migration between
MDSs.

Signed-off-by: Sage Weil <sage@newdream.net>
2010-11-07 09:39:23 -08:00
Sage Weil
2f56f56ad9 Revert "ceph: update issue_seq on cap grant"
This reverts commit d91f2438d8.

The intent of issue_seq is to distinguish between mds->client messages that
(re)create the cap and those that do not, which means we should _only_ be
updating that value in the create paths.  By updating it in handle_cap_grant,
we reset it to zero, which then breaks release.

The larger question is what workload/problem made me think it should be
updated here...

Signed-off-by: Sage Weil <sage@newdream.net>
2010-10-27 21:05:54 -07:00
Sage Weil
18a38193ef ceph: use mapping->nrpages to determine if mapping is empty
This is simpler and faster.

Signed-off-by: Sage Weil <sage@newdream.net>
2010-10-20 15:38:15 -07:00
Sage Weil
93afd449aa ceph: only invalidate on check_caps if we actually have pages
The i_rdcache_gen value only implies we MAY have cached pages; actually
check the mapping to see if it's worth bothering with an invalidate.

Signed-off-by: Sage Weil <sage@newdream.net>
2010-10-20 15:38:15 -07:00
Yehuda Sadeh
3d14c5d2b6 ceph: factor out libceph from Ceph file system
This factors out protocol and low-level storage parts of ceph into a
separate libceph module living in net/ceph and include/linux/ceph.  This
is mostly a matter of moving files around.  However, a few key pieces
of the interface change as well:

 - ceph_client becomes ceph_fs_client and ceph_client, where the latter
   captures the mon and osd clients, and the fs_client gets the mds client
   and file system specific pieces.
 - Mount option parsing and debugfs setup is correspondingly broken into
   two pieces.
 - The mon client gets a generic handler callback for otherwise unknown
   messages (mds map, in this case).
 - The basic supported/required feature bits can be expanded (and are by
   ceph_fs_client).

No functional change, aside from some subtle error handling cases that got
cleaned up in the refactoring process.

Signed-off-by: Sage Weil <sage@newdream.net>
2010-10-20 15:37:28 -07:00
Sage Weil
d91f2438d8 ceph: update issue_seq on cap grant
We need to update the issue_seq on any grant operation, be it via an MDS
reply or a separate grant message.  The update in the grant path was
missing.  This broke cap release for inodes in which the MDS sent an
explicit grant message that was not soon after followed by a successful
MDS reply on the same inode.

Also fix the signedness on seq locals.

Signed-off-by: Sage Weil <sage@newdream.net>
2010-10-07 08:01:50 -07:00
Greg Farnum
21b559de56 ceph: send cap release message early on failed revoke.
If an MDS tries to revoke caps that we don't have, we want to send
releases early since they probably contain the caps message the MDS
is looking for.

Previously, we only sent the messages if we didn't have the inode either. But
in a multi-mds system we can retain the inode after dropping all caps for
a single MDS.

Signed-off-by: Greg Farnum <gregf@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
2010-10-07 08:00:24 -07:00
Sage Weil
a43fb73101 ceph: check mapping to determine if FILE_CACHE cap is used
See if the i_data mapping has any pages to determine if the FILE_CACHE
capability is currently in use, instead of assuming it is any time the
rdcache_gen value is set (i.e., issued -> used).

This allows the MDS RECALL_STATE process work for inodes that have cached
pages.

Signed-off-by: Sage Weil <sage@newdream.net>
2010-09-17 09:54:31 -07:00
Sage Weil
e835124c2b ceph: only send one flushsnap per cap_snap per mds session
Sending multiple flushsnap messages is problematic because we ignore
the response if the tid doesn't match, and the server may only respond to
each one once.  It's also a waste.

So, skip cap_snaps that are already on the flushing list, unless the caller
tells us to resend (because we are reconnecting).

Signed-off-by: Sage Weil <sage@newdream.net>
2010-09-17 08:03:08 -07:00
Sage Weil
cfc0bf6640 ceph: stop sending FLUSHSNAPs when we hit a dirty capsnap
Stop sending FLUSHSNAP messages when we hit a capsnap that has dirty_pages
or is still writing.  We'll send the newer capsnaps only after the older
ones complete.

Signed-off-by: Sage Weil <sage@newdream.net>
2010-09-14 15:50:59 -07:00
Sage Weil
7d8cb26d7d ceph: maintain i_head_snapc when any caps are dirty, not just for data
We used to use i_head_snapc to keep track of which snapc the current epoch
of dirty data was dirtied under.  It is used by queue_cap_snap to set up
the cap_snap.  However, since we queue cap snaps for any dirty caps, not
just for dirty file data, we need to keep a valid i_head_snapc anytime
we have dirty|flushing caps.  This fixes a NULL pointer deref in
queue_cap_snap when writing back dirty caps without data (e.g.,
snaptest-authwb.sh).

Signed-off-by: Sage Weil <sage@newdream.net>
2010-08-24 16:24:18 -07:00
Sage Weil
4a625be472 ceph: include dirty xattrs state in snapped caps
When we snapshot dirty metadata that needs to be written back to the MDS,
include dirty xattr metadata.  Make the capsnap reference the encoded
xattr blob so that it will be written back in the FLUSHSNAP op.

Also fix the capsnap creation guard to include dirty auth or file bits,
not just tests specific to dirty file data or file writes in progress
(this fixes auth metadata writeback).

Signed-off-by: Sage Weil <sage@newdream.net>
2010-08-22 15:16:46 -07:00
Sage Weil
082afec92d ceph: fix xattr cap writeback
We should include the xattr metadata blob in the cap update message any
time we are flushing dirty state, NOT just when we are also dropping the
cap.  This fixes async xattr writeback.

Also, clean up the code slightly to avoid duplicating the bit test.

Signed-off-by: Sage Weil <sage@newdream.net>
2010-08-22 15:16:41 -07:00
Sage Weil
0eb6cd49f6 ceph: only queue async writeback on cap revocation if there is dirty data
Normally, if the Fb cap bit is being revoked, we queue an async writeback.
If there is no dirty data but we still hold the cap, this leaves the
client sitting around doing nothing until the cap timeouts expire and the
cap is released on its own (as it would have been without the revocation).

Instead, only queue writeback if the bit is actually used (i.e., we have
dirty data).  If not, we can reply to the revocation immediately.

Signed-off-by: Sage Weil <sage@newdream.net>
2010-08-05 13:53:40 -07:00