ceph: fix cap removal races

The iterate_session_caps helper traverses the session caps list and tries
to grab an inode reference. However, the __ceph_remove_cap was clearing
the ino

ceph: fix cap removal races

The iterate_session_caps helper traverses the session caps list and tries
to grab an inode reference. However, the __ceph_remove_cap was clearing
the inode backpointer _before_ removing itself from the session list,
causing a null pointer dereference.

Clear cap->ci under protection of s_cap_lock to avoid the race, and to
tightly couple the list and backpointer state. Use a local flag to
indicate whether we are releasing the cap, as cap->session may be modified
by a racing thread in iterate_session_caps.

Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: fix leaked spinlock during mds reconnect

Signed-off-by: Sage Weil <sage@newdream.net>

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:
ceph: use se

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:
ceph: use separate class for ceph sockets' sk_lock
ceph: reserve one more caps space when doing readdir
ceph: queue_cap_snap should always queue dirty context
ceph: fix dentry reference leak in dcache readdir
ceph: decode v5 of osdmap (pool names) [protocol change]
ceph: fix ack counter reset on connection reset
ceph: fix leaked inode ref due to snap metadata writeback race
ceph: fix snap context reference leaks
ceph: allow writeback of snapped pages older than 'oldest' snapc
ceph: fix dentry rehashing on virtual .snap dir

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ceph: fix leaked inode ref due to snap metadata writeback race

We create a ceph_cap_snap if there is dirty cap metadata (for writeback to
mds) OR dirty pages (for writeback to osd). It

ceph: fix leaked inode ref due to snap metadata writeback race

We create a ceph_cap_snap if there is dirty cap metadata (for writeback to
mds) OR dirty pages (for writeback to osd). It is thus possible that the
metadata has been written back to the MDS but the OSD data has not when
the cap_snap is created. This results in a cap_snap with dirty(caps) == 0.
The problem is that cap writeback to the MDS isn't necessary, and a
FLUSHSNAP cap op gets no ack from the MDS. This leaves the cap_snap
attached to the inode along with its inode reference.

Fix the problem by dropping the cap_snap if it becomes 'complete' (all
pages written out) and dirty(caps) == 0 in ceph_put_wrbuffer_cap_refs().

Also, BUG() in __ceph_flush_snaps() if we encounter a cap_snap with
dirty(caps) == 0.

Signed-off-by: Sage Weil <sage@newdream.net>

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include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
incl

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

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ceph: only release unused caps with mds requests

We were releasing used caps (e.g. FILE_CACHE) from encode_inode_release
with MDS requests (e.g. setattr). We don't carry refs on most ca

ceph: only release unused caps with mds requests

We were releasing used caps (e.g. FILE_CACHE) from encode_inode_release
with MDS requests (e.g. setattr). We don't carry refs on most caps, so
this code worked most of the time, but for setattr (utimes) we try to
drop Fscr.

This causes cap state to get slightly out of sync with reality, and may
result in subsequent mds revoke messages getting ignored.

Fix by only releasing unused caps.

Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: clean up handle_cap_grant, handle_caps wrt session mutex

Drop session mutex unconditionally in handle_cap_grant, and do the
check_caps from the handle_cap_grant helper. This avoid

ceph: clean up handle_cap_grant, handle_caps wrt session mutex

Drop session mutex unconditionally in handle_cap_grant, and do the
check_caps from the handle_cap_grant helper. This avoids using a magic
return value.

Also avoid using a flag variable in the IMPORT case and call
check_caps at the appropriate point.

Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: fix session locking in handle_caps, ceph_check_caps

Passing a session pointer to ceph_check_caps() used to mean it would leave
the session mutex locked. That wasn't always possibl

ceph: fix session locking in handle_caps, ceph_check_caps

Passing a session pointer to ceph_check_caps() used to mean it would leave
the session mutex locked. That wasn't always possible if it wasn't passed
CHECK_CAPS_AUTHONLY. If could unlock the passed session and lock a
differet session mutex, which was clearly wrong, and also emitted a
warning when it a racing CPU retook it and we did an unlock from the wrong
context.

This was only a problem when there was more than one MDS.

First, make ceph_check_caps unconditionally drop the session mutex, so that
it is free to lock other sessions as needed. Then adjust the one caller
that passes in a session (handle_cap_grant) accordingly.

Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: drop unnecessary WARN_ON in caps migration

If we don't have the exported cap it's because we already released it. No
need to WARN.

Signed-off-by: Sage Weil <sage@newdream.

ceph: drop unnecessary WARN_ON in caps migration

If we don't have the exported cap it's because we already released it. No
need to WARN.

Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: implemented caps should always be superset of issued caps

Added assertion, and cleared one case where the implemented caps were
not following the issued caps.

Signed-off-b

ceph: implemented caps should always be superset of issued caps

Added assertion, and cleared one case where the implemented caps were
not following the issued caps.

Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: update for write_inode API change

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Sage Weil <sage@newdream.net>

ceph: fix flush_dirty_caps race with caps migration

The flush_dirty_caps() used to loop over the first entry of the cap_dirty
dirty list on the assumption that after calling ceph_check_c

ceph: fix flush_dirty_caps race with caps migration

The flush_dirty_caps() used to loop over the first entry of the cap_dirty
dirty list on the assumption that after calling ceph_check_caps() it would
be removed from the list. This isn't true for caps that are being
migrated between MDSs, where we've received the EXPORT but not the IMPORT.

Instead, do a safe list iteration, and pin the next inode on the list via
the CEPH_I_NOFLUSH flag.

Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: include migrating caps in issued set

We should include caps that are mid-migration (we've received the EXPORT,
but not the IMPORT) in the issued caps set.

Signed-off-by: S

ceph: include migrating caps in issued set

We should include caps that are mid-migration (we've received the EXPORT,
but not the IMPORT) in the issued caps set.

Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: return EBADF if waiting for caps on closed file

Verify the file is actually open for the given caps when we are
waiting for caps. This ensures we will wake up and return EBADF

ceph: return EBADF if waiting for caps on closed file

Verify the file is actually open for the given caps when we are
waiting for caps. This ensures we will wake up and return EBADF
if another thread closes the file out from under us.

Note that EBADF is also the correct return code from write(2)
when called on a file handle opened for reading (although the
vfs should catch that).

Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: fix snaptrace decoding on cap migration between mds

This was simply broken. Apparently at some point we thought about putting
the snaptrace in the middle section, but didn't.

ceph: fix snaptrace decoding on cap migration between mds

This was simply broken. Apparently at some point we thought about putting
the snaptrace in the middle section, but didn't.

Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: drop messages on unregistered mds sessions; cleanup

Verify the mds session is currently registered before handling
incoming messages. Clean up message handlers to pull mds out

ceph: drop messages on unregistered mds sessions; cleanup

Verify the mds session is currently registered before handling
incoming messages. Clean up message handlers to pull mds out
of session->s_mds instead of less trustworthy src field.

Clean up con_{get,put} debug output.

Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: fix comments, locking in destroy_inode

The destroy_inode path needs no inode locks since there are no
inode references. Update __ceph_remove_cap comment to reflect
that it is

ceph: fix comments, locking in destroy_inode

The destroy_inode path needs no inode locks since there are no
inode references. Update __ceph_remove_cap comment to reflect
that it is called without cap->session->s_mutex in this case.

Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: cleanup redundant code in handle_cap_grant

There is no state in local vars that requires us to loop after temporarily
dropping i_lock.

Signed-off-by: Yehuda Sadeh <yehuda@

ceph: cleanup redundant code in handle_cap_grant

There is no state in local vars that requires us to loop after temporarily
dropping i_lock.

Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: fix check for invalidate_mapping_pages success

We need to know whether there was any page left behind, and not the
return value (the total number of pages invalidated). Look at th

ceph: fix check for invalidate_mapping_pages success

We need to know whether there was any page left behind, and not the
return value (the total number of pages invalidated). Look at the mapping
to see if we were successful or not.

Move it all into a helper to simplify the two callers.

Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: fix iterate_caps removal race

We need to be able to iterate over all caps on a session with a
possibly slow callback on each cap. To allow this, we used to
prevent cap reorder

ceph: fix iterate_caps removal race

We need to be able to iterate over all caps on a session with a
possibly slow callback on each cap. To allow this, we used to
prevent cap reordering while we were iterating. However, we were
not safe from races with removal: removing the 'next' cap would
make the next pointer from list_for_each_entry_safe be invalid,
and cause a lock up or similar badness.

Instead, we keep an iterator pointer in the session pointing to
the current cap. As before, we avoid reordering. For removal,
if the cap isn't the current cap we are iterating over, we are
fine. If it is, we clear cap->ci (to mark the cap as pending
removal) but leave it in the session list. In iterate_caps, we
can safely finish removal and get the next cap pointer.

While we're at it, clean up put_cap to not take a cap reservation
context, as it was never used.

Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: clean up readdir caps reservation

Use a global counter for the minimum number of allocated caps instead of
hard coding a check against readdir_max. This takes into account multipl

ceph: clean up readdir caps reservation

Use a global counter for the minimum number of allocated caps instead of
hard coding a check against readdir_max. This takes into account multiple
client instances, and avoids examining the superblock mount options when a
cap is dropped.

Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: remove bogus invalidate_mapping_pages

We were invalidating mapping pages when dropping FILE_CACHE in
__send_cap(). But ceph_check_caps attempts to invalidate already, and
also

ceph: remove bogus invalidate_mapping_pages

We were invalidating mapping pages when dropping FILE_CACHE in
__send_cap(). But ceph_check_caps attempts to invalidate already, and
also checks for success, so we should never get to this point.

Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: invalidate pages even if truncate is pending

There is no reason not to invalidate pages when a truncate is pending.
Both throw out page cache pages.

Signed-off-by: Sage We

ceph: invalidate pages even if truncate is pending

There is no reason not to invalidate pages when a truncate is pending.
Both throw out page cache pages.

Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: cleanup async writeback, truncation, invalidate helpers

Grab inode ref in helper. Make work functions static, with consistent
naming.

Signed-off-by: Sage Weil <sage@newdr

ceph: cleanup async writeback, truncation, invalidate helpers

Grab inode ref in helper. Make work functions static, with consistent
naming.

Signed-off-by: Sage Weil <sage@newdream.net>

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ceph: do not retain caps that are being revoked

Never retain caps in __send_cap() that are being revoked.

Signed-off-by: Sage Weil <sage@newdream.net>