linux.git/fs/ceph/snap.c, branch v4.13

ceph: convert ceph_cap_snap.nref from atomic_t to refcount_t

2017-05-04T07:19:18+00:00

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova 
Signed-off-by: Hans Liljestrand 
Signed-off-by: Kees Cook 
Signed-off-by: David Windsor 
Signed-off-by: Ilya Dryomov

ceph: record truncate size/seq for snap data writeback

2016-12-12T22:54:27+00:00

Dirty snapshot data needs to be flushed unconditionally. If they
were created before truncation, writeback should use old truncate
size/seq.

Signed-off-by: Yan, Zheng

ceph: cleanup ceph_flush_snaps()

2016-07-28T01:00:44+00:00

This patch devide __ceph_flush_snaps() into two stags. In the first
stage, __ceph_flush_snaps() assign snapcaps flush TIDs and add them
to cap flush lists. __ceph_flush_snaps() keeps holding the
i_ceph_lock in this stagge. So inode's auth cap can not change. In
the second stage, __ceph_flush_snaps() send flushsnap cap messages.
i_ceph_lock is unlocked before sending each cap message. If auth cap
changes in the middle, __ceph_flush_snaps() just stops. This is OK
because kick_flushing_inode_caps() will re-send flushsnap cap messages
to inode's new auth MDS.

Signed-off-by: Yan, Zheng

ceph: introduce an inode flag to indicates if snapflush is needed

2016-07-28T01:00:43+00:00

Signed-off-by: Yan, Zheng

ceph: unify cap flush and snapcap flush

2016-07-28T01:00:42+00:00

This patch includes following changes
- Assign flush tid to snapcap flush
- Remove session's s_cap_snaps_flushing list. Add inode to session's
  s_cap_flushing list instead. Inode is removed from the list when
  there is no pending snapcap flush or cap flush.
- make __kick_flushing_caps() re-send both snapcap flushes and cap
  flushes.

Signed-off-by: Yan, Zheng

ceph: fix NULL dereference in ceph_queue_cap_snap()

2016-07-28T00:55:40+00:00

old_snapc->seq is used in dout(...)

Signed-off-by: Yan, Zheng

ceph: kill ceph_empty_snapc

2016-03-25T17:51:52+00:00

ceph_empty_snapc->num_snaps == 0 at all times.  Passing such a snapc to
ceph_osdc_alloc_request() (possibly through ceph_osdc_new_request()) is
equivalent to passing NULL, as ceph_osdc_alloc_request() uses it only
for sizing the request message.

Further, in all four cases the subsequent ceph_osdc_build_request() is
passed NULL for snapc, meaning that 0 is encoded for seq and num_snaps
and making ceph_empty_snapc entirely useless.  The two cases where it
actually mattered were removed in commits 860560904962 ("ceph: avoid
sending unnessesary FLUSHSNAP message") and 23078637e054 ("ceph: fix
queuing inode to mdsdir's snaprealm").

Signed-off-by: Ilya Dryomov 
Reviewed-by:  Yan, Zheng

ceph: fix queuing inode to mdsdir's snaprealm

2015-09-08T20:14:29+00:00

During MDS failovers, MClientSnap message may cause kclient to move
some inodes from root directory's snaprealm to mdsdir's snaprealm
and queue snapshots for these inodes. For a FS has never created any
snapshot, both root directory's snaprealm and mdsdir's snaprealm
share the same snapshot contexts (both are ceph_empty_snapc). This
confuses ceph_put_wrbuffer_cap_refs(), make it unable to distinguish
snapshot buffers from head buffers.

The fix is do not use ceph_empty_snapc as snaprealm's cached context.

Signed-off-by: Yan, Zheng

ceph: make sure syncfs flushes all cap snaps

2015-06-25T08:49:29+00:00

Signed-off-by: Yan, Zheng

ceph: avoid sending unnessesary FLUSHSNAP message

2015-06-25T08:49:28+00:00

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: Yan, Zheng