Durring orphan scan, if we are slot 0, and we are replaying
orphan_dir:0001, the general process is that for every file
in this dir:
1. we will iget orphan_dir:0001, since there is no inode for it.
we will have to create an inode and read it from the disk.
2. do the normal work, such as delete_inode and remove it from
the dir if it is allowed.
3. call iput orphan_dir:0001 when we are done. In this case,
since we have no dcache for this inode, i_count will
reach 0, and VFS will have to call clear_inode and in
ocfs2_clear_inode we will checkpoint the inode which will let
ocfs2_cmt and journald begin to work.
4. We loop back to 1 for the next file.
So you see, actually for every deleted file, we have to read the
orphan dir from the disk and checkpoint the journal. It is very
time consuming and cause a lot of journal checkpoint I/O.
A better solution is that we can have another reference for these
inodes in ocfs2_super. So if there is no other race among
nodes(which will let dlmglue to checkpoint the inode), for step 3,
clear_inode won't be called and for step 1, we may only need to
read the inode for the 1st time. This is a big win for us.
So this patch will try to cache system inodes of other slots so
that we will have one more reference for these inodes and avoid
the extra inode read and journal checkpoint.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
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>
Actually ocfs2_sysfile_cluster_lock_key is only used if we enable
CONFIG_DEBUG_LOCK_ALLOC. Wrap it so that we can avoid a building
warning.
fs/ocfs2/sysfile.c:53: warning: ‘ocfs2_sysfile_cluster_lock_key’
defined but not used
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Add lockdep support to OCFS2. The support also covers all of the cluster
locks except for open locks, journal locks, and local quotafile locks. These
are special because they are acquired for a node, not for a particular process
and lockdep cannot deal with such type of locking.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Create separate lockdep lock classes for system file's i_mutexes. They are
used to guard allocations and similar things and thus rank differently
than i_mutex of a regular file or directory.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
A couple paths which needed to just match a parent dir + name pair to an
inode number were a bit messy because they had to deal with
ocfs2_find_files_on_disk() which returns a larger number of values. Provide
a convenience function, ocfs2_lookup_ino_from_name() which internalizes all
the extra accounting.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Reviewed-by: Joel Becker <joel.becker@oracle.com>
OCFS2 puts inode meta data in the "lock value block" provided by the DLM.
Typically, i_generation is encoded in the lock name so that a deleted inode
on and a new one in the same block don't share the same lvb.
Unfortunately, that scheme means that the read in ocfs2_read_locked_inode()
is potentially thrown away as soon as the meta data lock is taken - we
cannot encode the lock name without first knowing i_generation, which
requires a disk read.
This patch encodes i_generation in the inode meta data lvb, and removes the
value from the inode meta data lock name. This way, the read can be covered
by a lock, and at the same time we can distinguish between an up to date and
a stale LVB.
This will help cold-cache stat(2) performance in particular.
Since this patch changes the protocol version, we take the opportunity to do
a minor re-organization of two of the LVB fields.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Replace the dentry vote mechanism with a cluster lock which covers a set
of dentries. This allows us to force d_delete() only on nodes which actually
care about an unlink.
Every node that does a ->lookup() gets a read only lock on the dentry, until
an unlink during which the unlinking node, will request an exclusive lock,
forcing the other nodes who care about that dentry to d_delete() it. The
effect is that we retain a very lightweight ->d_revalidate(), and at the
same time get to make large improvements to the average case performance of
the ocfs2 unlink and rename operations.
This patch adds the higher level API and the dentry manipulation code.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Tao Ma
Tao Ma
Tejun Heo
Jan Kara
Mark Fasheh
Eric Sesterhenn / snakebyte