Fix the race between invalidate_inode_pages and do_no_page.
Andrea Arcangeli identified a subtle race between invalidation of pages from
pagecache with userspace mappings, and do_no_page.
The issue is that invalidation has to shoot down all mappings to the page,
before it can be discarded from the pagecache. Between shooting down ptes to
a particular page, and actually dropping the struct page from the pagecache,
do_no_page from any process might fault on that page and establish a new
mapping to the page just before it gets discarded from the pagecache.
The most common case where such invalidation is used is in file truncation.
This case was catered for by doing a sort of open-coded seqlock between the
file's i_size, and its truncate_count.
Truncation will decrease i_size, then increment truncate_count before
unmapping userspace pages; do_no_page will read truncate_count, then find the
page if it is within i_size, and then check truncate_count under the page
table lock and back out and retry if it had subsequently been changed (ptl
will serialise against unmapping, and ensure a potentially updated
truncate_count is actually visible).
Complexity and documentation issues aside, the locking protocol fails in the
case where we would like to invalidate pagecache inside i_size. do_no_page
can come in anytime and filemap_nopage is not aware of the invalidation in
progress (as it is when it is outside i_size). The end result is that
dangling (->mapping == NULL) pages that appear to be from a particular file
may be mapped into userspace with nonsense data. Valid mappings to the same
place will see a different page.
Andrea implemented two working fixes, one using a real seqlock, another using
a page->flags bit. He also proposed using the page lock in do_no_page, but
that was initially considered too heavyweight. However, it is not a global or
per-file lock, and the page cacheline is modified in do_no_page to increment
_count and _mapcount anyway, so a further modification should not be a large
performance hit. Scalability is not an issue.
This patch implements this latter approach. ->nopage implementations return
with the page locked if it is possible for their underlying file to be
invalidated (in that case, they must set a special vm_flags bit to indicate
so). do_no_page only unlocks the page after setting up the mapping
completely. invalidation is excluded because it holds the page lock during
invalidation of each page (and ensures that the page is not mapped while
holding the lock).
This also allows significant simplifications in do_no_page, because we have
the page locked in the right place in the pagecache from the start.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since gfs2 can't prevent conflicting opens or leases on other nodes, we
probably shouldn't allow it to give out leases at all.
Put the newly defined lease operation into use in gfs2 by turning off
lease, unless we're using the "nolock' locking module (in which case all
locking is local anyway).
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
They can use generic_file_splice_read() instead. Since sys_sendfile() now
prefers that, there should be no change in behaviour.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch cleans up the inode number handling code. The main difference
is that instead of looking up the inodes using a struct gfs2_inum_host
we now use just the no_addr member of this structure. The tests relating
to no_formal_ino can then be done by the calling code. This has
advantages in that we want to do different things in different code
paths if the no_formal_ino doesn't match. In the NFS patch we want to
return -ESTALE, but in the ->lookup() path, its a bug in the fs if the
no_formal_ino doesn't match and thus we can withdraw in this case.
In order to later fix bz #201012, we need to be able to look up an inode
without knowing no_formal_ino, as the only information that is known to
us is the on-disk location of the inode in question.
This patch will also help us to fix bz #236099 at a later date by
cleaning up a lot of the code in that area.
There are no user visible changes as a result of this patch and there
are no changes to the on-disk format either.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.
Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add NFS lock support to GFS2.
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
posix_test_lock() and ->lock() do the same job but have gratuitously
different interfaces. Modify posix_test_lock() so the two agree,
simplifying some code in the process.
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there. Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.
To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.
Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm. I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).
Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This removes the extra filldir callback which gfs2 was using to
enclose an attempt at readahead for inodes during readdir. The
code was too complicated and also hurts performance badly in the
case that the getdents64/readdir call isn't being followed by
stat() and it wasn't even getting it right all the time when it
was.
As a result, on my test box an "ls" of a directory containing 250000
files fell from about 7mins (freshly mounted, so nothing cached) to
between about 15 to 25 seconds. When the directory content was cached,
the time taken fell from about 3mins to about 4 or 5 seconds.
Interestingly in the cached case, running "ls -l" once reduced the time
taken for subsequent runs of "ls" to about 6 secs even without this
patch. Now it turns out that there was a special case of glocks being
used for prefetching the metadata, but because of the timeouts for these
locks (set to 10 secs) the metadata was being timed out before it was
being used and this the prefetch code was constantly trying to prefetch
the same data over and over.
Calling "ls -l" meant that the inodes were brought into memory and once
the inodes are cached, the glocks are not disposed of until the inodes
are pushed out of the cache, thus extending the lifetime of the glocks,
and thus bringing down the time for subsequent runs of "ls"
considerably.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This is a bit better than the previous version of gfs2_fsync()
although it would be better still if we were able to call a
function which only wrote the inode & metadata. Its no big deal
though that this will potentially write the data as well since
the VFS has already done that before calling gfs2_fsync(). I've
also added a comment to explain whats going on here.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Morton <akpm@osdl.org>
The gfs2_fsync() function was doing a journal flush on each
and every call. While this is correct, its also a lot of
overhead. This patch means that on fdatasync flushes we
rely on the VFS to flush the data for us and we don't do
a journal flush unless we really need to.
We have to do a journal flush for stuffed files though because
they have the data and the inode metadata in the same block.
Journaled files also need a journal flush too of course.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
The gfs2_glock_nq_m_atime function is unused in so far as its only
ever called with num_gh = 1, and this falls through to the
gfs2_glock_nq_atime function, so we might as well call that directly.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
We were setting the inode flags from GFS2's flags far too often, even when they
couldn't possibly have changed. This patch reduces the amount of flag
setting going on so that we do it only when the inode is read in or
when the flags have changed. The create case is covered by the "when
the inode is read in" case.
This also fixes a bug where we didn't set S_SYNC correctly.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This removes the duplicate di_mode field in favour of using the
inode->i_mode field. This saves 4 bytes.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Everywhere this was called, a struct gfs2_inode was available,
but despite that, it was always called with a struct gfs2_dinode
as an argument. By making this change it paves the way to start
eliminating fields duplicated between the kernel's struct inode
and the struct gfs2_dinode.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Update GFS2 in the light of David Howells' patch:
[PATCH] BLOCK: Move common FS-specific ioctls to linux/fs.h [try #6]
36695673b0
which calls the filesystem independant flags FS_..._FL. As a result
we no longer need the flags.h file and the conversion routine is
moved into the GFS2 source code.
Userland programs which used to include iflags.h should now include
fs.h and use the new flag names.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Fix GFS for streamline-generic_file_-interfaces-and-filemap.patch
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch removes readv() and writev() methods and replaces them with
aio_read()/aio_write() methods.
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
lm_interface.h has a few out of the tree clients such as GFS1
and userland tools.
Right now, these clients keeps a copy of the file in their build tree
that can go out of sync.
Move lm_interface.h to include/linux, export it to userland and
clean up fs/gfs2 to use the new location.
Signed-off-by: Fabio M. Di Nitto <fabbione@ubuntu.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
As per Jan Engelhardt's fifth email. This has most of the changes
recommended, which is the removal of casts which are not required,
some indenting fixes and similar.
Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This makes all fixed size types have consistent names.
Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
As per comments from Jan Engelhardt <jengelh@linux01.gwdg.de> this
updates the copyright message to say "version" in full rather than
"v.2". Also incore.h has been updated to remove forward structure
declarations which are not required.
The gfs2_quota_lvb structure has now had endianess annotations added
to it. Also quota.c has been updated so that we now store the
lvb data locally in endian independant format to avoid needing
a structure in host endianess too. As a result the endianess
conversions are done as required at various points and thus the
conversion routines in lvb.[ch] are no longer required. I've
moved the one remaining constant in lvb.h thats used into lm.h
and removed the unused lvb.[ch].
I have not changed the HIF_ constants. That is left to a later patch
which I hope will unify the gh_flags and gh_iflags fields of the
struct gfs2_holder.
Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Tidy up some files and remove an unused routine in meta_io.h. Also
added a bit of extra debugging in meta_io.h.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
As per comments received, alter the GFS2 direct I/O path so that
it uses the standard read functions "out of the box". Needs a
small change to one of the VFS functions. This reduces the size
of the code quite a lot and also removes the need for one new export.
Some more work remains to be done, but this is the bones of the
thing.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
traced the "umount hang due to spurious glock" issue that I was having
with gfs2meta. It's in the do_gfs2_set_flags function, which does a
gfs2_holder_init as well as a gfs2_glock_nq_init (increases ref count by
2 instead of 1).
Signed-off-by: Abhijith Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This adds a generation number for the eventual use of NFS to the
ondisk inode. Its backward compatible with the current code since
it doesn't really matter what the generation number is to start with,
and indeed since its set to zero, due to it being taken from padding
in both the inode and rgrp header, it should be fine.
The eventual plan is to use this rather than no_formal_ino in the
NFS filehandles. At that point no_formal_ino will be unused.
At the same time we also add a releasepages call back to the
"normal" address space for gfs2 inodes. Also I've removed a
one-linrer function thats not required any more.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Don't use a wrapper for generic_file_sendfile but call it
directly.
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
gfs2_repermission is just a wrapper for permission, so remove it and
call permission directly where required.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch fixes the way we have been dealing with unlinked,
but still open files. It removes all limits (other than memory
for inodes, as per every other filesystem) on numbers of these
which we can support on GFS2. It also means that (like other
fs) its the responsibility of the last process to close the file
to deallocate the storage, rather than the person who did the
unlinking. Note that with GFS2, those two events might take place
on different nodes.
Also there are a number of other changes:
o We use the Linux inode subsystem as it was intended to be
used, wrt allocating GFS2 inodes
o The Linux inode cache is now the point which we use for
local enforcement of only holding one copy of the inode in
core at once (previous to this we used the glock layer).
o We no longer use the unlinked "special" file. We just ignore it
completely. This makes unlinking more efficient.
o We now use the 4th block allocation state. The previously unused
state is used to track unlinked but still open inodes.
o gfs2_inoded is no longer needed
o Several fields are now no longer needed (and removed) from the in
core struct gfs2_inode
o Several fields are no longer needed (and removed) from the in core
superblock
There are a number of future possible optimisations and clean ups
which have been made possible by this patch.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
We no longer use semaphores, everything has been converted to
mutex or rwsem, so we don't need to include this header any more.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
The attributes logic for immutable was wrong so that there was
not way to remove this attribute once set. This fixes the
bug.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
We don't need the inherited flags since this action can be
implied by setting the flags on directories where they
wouldn't otherwise make sense. It reduces the number of extra
flags by two. Also updated the list of flags to take account of
one extra ext2/3 flag.
Cc: Andreas Dilger <adilger@clusterfs.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This fixes a ref count bug that sometimes showed up a umount time
(causing it to hang) but it otherwise mostly harmless. At the same
time there are some clean ups including making the log operations
structures const, moving a memory allocation so that its not done
in the fast path of checking to see if there is an outstanding
transaction related to a particular glock.
Removes the sd_log_wrap varaible which was updated, but never actually
used anywhere. Updates the gfs2 ioctl() to run without the kernel lock
(which it never needed anyway). Removes the "invalidate inodes" loop
from GFS2's put_super routine. This is done in kill super anyway so
we don't need to do it here. The loop was also bogus in that if there
are any inodes "stuck" at this point its a bug and we need to know
about it rather than hide it by hanging forever.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This puts the finishing touches to the ioctl support and also
removes a couple of unused fields from GFS2's private per file
structure.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Some interfaces have changed. In particular one of the posix
locking functions has changed prototype, along with the
address space operation invalidatepage and the block getting
callback to the direct IO function.
In addition add the splice file operations. These will need to
be updated to support AOP_TRUNCATED_PAGE before they will be
of much use to us.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This is designed as a fs independent way to set flags on a
particular inode. The values of the ioctl() and flags are
designed to be identical to the ext2/3 values. Assuming that
this plan is acceptable to people in general, the plan is to
then move other fs across to using the same set of #defines,
etc.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This reduces the size of the directory code by about 3k and gets
readdir() to use the functions which were introduced in the previous
directory code update.
Two memory allocations are merged into one. Eliminates zeroing of some
buffers which were never used before they were initialised by
other data.
There is still scope for further improvement in the directory code.
On the logging side, a hand created mutex has been replaced by a
standard Linux mutex in the log allocation code.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
The various flags on inodes will in future be set and queried
via the extended attributes interface, so this interface is no
longer required.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
As suggested by Pekka Enberg <penberg@cs.helsinki.fi>.
The DIV_RU macro is renamed DIV_ROUND_UP and and moved to kernel.h
The other macros are gone from gfs2.h as (although not requested
by Pekka Enberg) are a number of included header file which are now
included individually. The inode number comparison function is
now an inline function.
The DT2IF and IF2DT may be addressed in a future patch.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
