This patch fixes bz 450641.
This patch changes the computation for zero_metapath_length(), which it
renames to metapath_branch_start(). When you are extending the metadata
tree, The indirect blocks that point to the new data block must either
diverge from the existing tree either at the inode, or at the first
indirect block. They can diverge at the first indirect block because the
inode has room for 483 pointers while the indirect blocks have room for
509 pointers, so when the tree is grown, there is some free space in the
first indirect block. What metapath_branch_start() now computes is the
height where the first indirect block for the new data block is located.
It can either be 1 (if the indirect block diverges from the inode) or 2
(if it diverges from the first indirect block).
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch streamlines the quota checking in the "no quota" case by
making the check inline in the calling function, thus reducing the
number of function calls. Eventually we might be able to remove the
checks from the gfs2_quota_lock() and gfs2_quota_check() functions, but
currently we can't as there are a very few places in the code which need
to call these functions directly still.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Abhijith Das <adas@redhat.com>
gfs2_alloc_get may fail so we have to check it to prevent
NULL pointer dereference.
Signed-off-by: Cyrill Gorcunov <gorcunov@gamil.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
We've supported mapping of extents when no block allocation is required
for some time. This patch extends that to mapping of extents when an
allocation has been requested. In that case we try to allocate as many
blocks as are requested, but we might return fewer in case there is
something preventing us from returning the complete amount (e.g. an
already allocated block is in the way).
Currently the only code path which can actually request multiple data
blocks in a single bmap call is the page_mkwrite path and even then it
only happens if there are multiple blocks per page. What this patch does
do however, is merge the allocation requests for metadata (growing the
metadata tree in either height or depth) with the allocation of the data
blocks in the case that both are needed. This results in lower overheads
even in the single block allocation case.
The one thing which we can't handle here at the moment is unstuffing. I
would like to be able to do that, but the problem which arises is that
in order to unstuff one has to get a locked page from the page cache
which results in locking problems in the (usual) case that the caller is
holding the page lock on the page it wishes to map. So that case will
have to be addressed in future patches.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
In the case that we needed to grow the height of the metadata tree
we were looking up the inode buffer and then brelse()ing it despite
the fact that it is needed later in the block map process.
This patch ensures that we look up the inode's buffer once and only
once during the block map process.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
The blocks counter is almost a duplicate of the i_blocks
field in the VFS inode. The only difference is that i_blocks
can be only 32bits long for 32bit arch without large single file
support. Since GFS2 doesn't handle the non-large single file
case (for 32 bit anyway) this adds a new config dependency on
64BIT || LSF. This has always been the case, however we've never
explicitly said so before.
Even if we do add support for the non-LSF case, we will still
not require this field to be duplicated since we will not be
able to access oversized files anyway.
So the net result of all this is that we shave 8 bytes from a gfs2_inode
and get our config deps correct.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This adds a function (currently the only use is during mapping
of already allocated blocks, but watch this space) which iterates
over a number of pointers in a block and returns the extent length.
If the initial pointer is 0 (i.e. unallocated) it will return the
number of unallocated blocks in the extent. If the initial pointer
is allocated, then it returns the number of contiguously allocated
blocks in the extent.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Rather than having to allocate a single block at a time, this patch
allows the block allocator to allocate an extent. Since there is
no difference (so far as the block allocator is concerned) between
data blocks and indirect blocks, it is posible to allocate a single
extent and for the caller to unrevoke just the blocks required
for indirect blocks.
Currently the only bit of GFS2 to make use of this feature is the
build height function. The intention is that gfs2_block_map will
be changed to make use of this feature in future patches.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Thanks to the preceeding patches, the only difference between
these two functions is their name. We can thus merge them
and call the new function gfs2_alloc_block to reflect the
fact that it can allocate either kind of block.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
By adding an extra argument to gfs2_trans_add_unrevoke we can now
specify an extent length of blocks to unrevoke. This means that
we only need to make one pass through the list for each extent
rather than each block. Currently the only extent length which
is used is 1, but that will change in the future.
Also gfs2_trans_add_unrevoke is removed from gfs2_alloc_meta
since its the only difference between this and gfs2_alloc_data
which is left. This will allow a future patch to merge these
two functions into one (i.e. one call to allocate both data
and metadata in a single extent in the future).
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
There were three fields being used to keep track of the location
of the most recently allocated block for each inode. These have
been merged into a single field in order to better keep the
data and metadata for an inode close on disk, and also to reduce
the space required for storage.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
The reason for doing this is to allow all the block mapping code
to share the same array. As a result we can remove two arguments
from lookup_metapath since they are now returned via the array.
We also add a function to drop all refs to buffer heads when we
are done with the metapath. The build_height function shares the
struct metapath, but currently still frees its own buffers, and
this will change in a future patch.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch contains two small fixups that didn't fit elsewhere.
They are: (1) get rid of temp variable in find_metapath.
(2) Remove vestigial "ret" variable from gfs2_writepage_common.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch removed the unnecessary parameter from function
gfs2_rlist_alloc. The parameter was always passed in as 0.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch improves the calculation of the tree height in order to reduce
the number of operations which are carried out on each call to gfs2_block_map.
In the common case, we now make a single comparison, rather than calculating
the required tree height from scratch each time. Also in the case that the
tree does need some extra height, we start from the current height rather from
zero when we work out what the new height ought to be.
In addition the di_height field is moved into the inode proper and reduced
in size to a u8 since the value must be between 0 and GFS2_MAX_META_HEIGHT (10).
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch removes the call to gfs2_extent_map from gfs2_write_alloc_required,
instead we call gfs2_block_map directly. This results in fewer overall calls
to gfs2_block_map in the multi-block case.
Also, gfs2_extent_map is marked as deprecated so that people know that its
going away as soon as all the callers have been converted.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Simplify page cache zeroing of segments of pages through 3 functions
zero_user_segments(page, start1, end1, start2, end2)
Zeros two segments of the page. It takes the position where to
start and end the zeroing which avoids length calculations and
makes code clearer.
zero_user_segment(page, start, end)
Same for a single segment.
zero_user(page, start, length)
Length variant for the case where we know the length.
We remove the zero_user_page macro. Issues:
1. Its a macro. Inline functions are preferable.
2. The KM_USER0 macro is only defined for HIGHMEM.
Having to treat this special case everywhere makes the
code needlessly complex. The parameter for zeroing is always
KM_USER0 except in one single case that we open code.
Avoiding KM_USER0 makes a lot of code not having to be dealing
with the special casing for HIGHMEM anymore. Dealing with
kmap is only necessary for HIGHMEM configurations. In those
configurations we use KM_USER0 like we do for a series of other
functions defined in highmem.h.
Since KM_USER0 is depends on HIGHMEM the existing zero_user_page
function could not be a macro. zero_user_* functions introduced
here can be be inline because that constant is not used when these
functions are called.
Also extract the flushing of the caches to be outside of the kmap.
[akpm@linux-foundation.org: fix nfs and ntfs build]
[akpm@linux-foundation.org: fix ntfs build some more]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: David Chinner <dgc@sgi.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a small I/O performance enhancement to gfs2. (Actually, it is a rework of
an earlier version I got wrong). The idea here is to check if the write extends
past the last block in the file. If so, the function can save itself a lot of
time and trouble because it knows an allocate will be required. Benchmarks like
iozone should see better performance.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
It is possible to reduce the size of GFS2 inodes by taking the i_alloc
structure out of the gfs2_inode. This patch allocates the i_alloc
structure whenever its needed, and frees it afterward. This decreases
the amount of low memory we use at the expense of requiring a memory
allocation for each page or partial page that we write. A quick test
with postmark shows that the overhead is not measurable and I also note
that OCFS2 use the same approach.
In the future I'd like to solve the problem by shrinking down the size
of the members of the i_alloc structure, but for now, this reduces the
immediate problem of using too much low-memory on x86 and doesn't add
too much overhead.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Function gfs2_block_map was often looking up the disk inode twice.
This optimizes it so that only does it once.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch is just a cleanup. Function gfs2_get_block() just calls
function gfs2_block_map reversing the last two parameters. By
reversing the parameters, gfs2_block_map() may be called directly
and function gfs2_get_block may be eliminated altogether.
Since this function is done for every block operation,
this streamlines the code and makes it a little bit more efficient.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This adds a function "gfs2_is_writeback()" along the lines of the
existing "gfs2_is_jdata()" in order to clean up the code and make
the various tests for the inode mode more obvious. It also fixes
the PageChecked() logic where we were resetting the flag too early
in the case of an error path.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Current GFS2 setattr call unconditionally invokes do_shrink even the
requested size and actual file size are equal. This has generated large
amount of extra IOs found during NFS benchmark runs. This patch moves
the relevant logic out of shrink code path. Since setattr is a system
call, the time stamps update is still required.
Signed-off-by: S. Wendy Cheng <wcheng@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Code segment inside gfs2_block_truncate_page() doesn't set the return
code correctly. This causes NFSD erroneously returns EIO back to client
with setattr procedure call (truncate error).
Signed-off-by: S. Wendy Cheng <wcheng@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This adds a nanosecond timestamp feature to the GFS2 filesystem. Due
to the way that the on-disk format works, older filesystems will just
appear to have this field set to zero. When mounted by an older version
of GFS2, the filesystem will simply ignore the extra fields so that
it will again appear to have whole second resolution, so that its
trivially backward compatible.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch fixes some sign issues which were accidentally introduced
into the quota & statfs code during the endianess annotation process.
Also included is a general clean up which moves all of the _host
structures out of gfs2_ondisk.h (where they should not have been to
start with) and into the places where they are actually used (often only
one place). Also those _host structures which are not required any more
are removed entirely (which is the eventual plan for all of them).
The conversion routines from ondisk.c are also moved into the places
where they are actually used, which for almost every one, was just one
single place, so all those are now static functions. This also cleans up
the end of gfs2_ondisk.h which no longer needs the #ifdef __KERNEL__.
The net result is a reduction of about 100 lines of code, many functions
now marked static plus the bug fixes as mentioned above. For good
measure I ran the code through sparse after making these changes to
check that there are no warnings generated.
This fixes Red Hat bz #239686
Signed-off-by: Steven Whitehouse <swhiteho@redhat.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>
Use zero_user_page() instead of open-coding it.
Signed-off-by: Nate Diller <nate.diller@gmail.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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>
I was looking something else up and came across this...
I don't honestly have a good reason to change it other than to make it
like every other Linux filesystem in this regard. ;-) It doesn't
functionally change anything, but makes some lines shorter. :)
I'm also curious; why does gfs2 have 64-bits of on-disk timestamps, but
not in timespec_t format, and only stores second resolutions? Seems like
you're halfway to sub-second resolutions already.
I suppose if that gets implemented then all of the below should
instead be CURRENT_TIME not CURRENT_TIME_SEC.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This moves the locking for bmap into the bmap function itself
rather than using a wrapper function. It also fixes a bug where
the boundary flag was set on the wrong bh. Also the flags on
the mapped bh are reset earlier in the function to ensure that
they are 100% correct on the error path.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This function wasn't really doing the right thing. There was no need
to update the inode size at this point and the updating of the
i_blocks field has now been moved to the places where di_blocks is
updated. A result of this patch and some those preceeding it is that
unlocking a glock is now a much more efficient process, since there
is no longer any requirement to copy data from the gfs2 inode into
the vfs inode at this point.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Remove the di_[amc]time fields and use inode->i_[amc]time
fields instead. This saves 24 bytes from the gfs2_inode.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Remove duplicate di_uid/di_gid fields in favour of using
inode->i_uid/inode->i_gid instead. This saves 8 bytes.
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>
This fix means that bmap will map extents of the length requested
by the VFS rather than guessing at it, or just mapping one block
at a time. The other callers of gfs2_block_map are audited to ensure
they send the correct max extent lengths (i.e. set bh->b_size correctly).
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
In many places GFS2 was calling the endian conversion routines
for an inode even when only a single field, or a few fields might
have changed. As a result we were copying lots of data needlessly.
This patch replaces those calls with conversion of just the
required fields in each case. This should be faster and easier
to understand. There are still other places which suffer from this
problem, but this is a start in the right direction.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Fix a bug in the directory reading code, where we might have dereferenced
a NULL pointer in case of OOM. Updated the directory code to use the new
& improved version of gfs2_meta_ra() which now returns the first block
that was being read. Previously it was releasing it requiring following
code to grab the block again at each point it was called.
Also turned off readahead on directory lookups since we are reading a
hash table, and therefore reading the entries in order is very
unlikely. Readahead is still used for all other calls to the
directory reading function (e.g. when growing the hash table).
Removed the DIO_START constant. Everywhere this was used, it was
used to unconditionally start i/o aside from a couple of places, so
I've removed it and made the couple of exceptions to this rule into
separate functions.
Also hunted through the other DIO flags and removed them as arguments
from functions which were always called with the same combination of
arguments.
Updated gfs2_meta_indirect_buffer to be a bit more efficient and
hopefully also be a bit easier to read.
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>
i_blksize got removed in -mm.
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This is a tidy up of the GFS2 bmap code. The main change is that the
bh is passed to gfs2_block_map allowing the flags to be set directly
rather than having to repeat that code several times in ops_address.c.
At the same time, the extent mapping code from gfs2_extent_map has
been moved into gfs2_block_map. This allows all calls to gfs2_block_map
to map extents in the case that no allocation is taking place. As a
result reads and non-allocating writes should be faster. A quick test
with postmark appears to support this.
There is a limit on the number of blocks mapped in a single bmap
call in that it will only ever map blocks which are pointed to
from a single pointer block. So in other words, it will never try
to do additional i/o in order to satisfy read-ahead. The maximum
number of blocks is thus somewhat less than 512 (the GFS2 4k block
size minus the header divided by sizeof(u64)). I've further limited
the mapping of "normal" blocks to 32 blocks (to avoid extra work)
since readpages() will currently read a maximum of 32 blocks ahead (128k).
Some further work will probably be needed to set a suitable value
for DIO as well, but for now thats left at the maximum 512 (see
ops_address.c:gfs2_get_block_direct).
There is probably a lot more that can be done to improve bmap for GFS2,
but this is a good first step.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
The remains of the changes for Jan Engelhardt's third email. Remove
a cast and tidy up gfs2_inode_attr_in.
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 Jan Engelhardt's third set of comments, this make various
code style changes and moves the structures from format.h into
super.c, which was the only place that format.h was actually used.
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>
The remaining routines in page.c were all only used in one other
file, so they are now moved into the files where they are referenced
and made static. Thus page.[ch] are no longer required.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Tidy up gfs2_unstuffer_page by:
a) Moving it into bmap.c
b) Making it static
c) Calling it directly from gfs2_unstuff_dinode
d) Updating all callers of gfs2_unstuff_dinode due to one less
required argument.
It doesn't change the behaviour at all.
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 original code ordered the blocks allocated in the build_height
routine backwards causing excessive disk seeks during a read of the
metadata. This patch reverses the order to try and reduce disk seeks.
Example: A five level metadata tree, I = Inode, P = Pointers, D = Data
You need to read the blocks in the order:
I P5 P4 P3 P2 P1 D
in order to read a single data block. The new code now orders the blocks
in this way. The old code used to order them as:
I P1 P2 P3 P4 P5 D
requiring two extra seeks on average. Note that for files which are
grown by gradual extension rather than by truncate or by llseek/write
at a large offset, this doesn't apply. In the case of writing to a
file linearly, this routine will only be called upon to extend the
height of the tree by one block at a time, so the ordering is
determined by when its called rather than by the internals of the
routine itself. Optimising that part of the ordering is a much
harder problem.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This adds readpages support (and also corrects a small bug in
the readpage error path at the same time). Hopefully this will
improve performance by allowing GFS to submit larger lumps of
I/O at a time.
In order to simplify the setting of BH_Boundary, it currently gets
set when we hit the end of a indirect pointer block. There is
always a boundary at this point with the current allocation code.
It doesn't get all the boundaries right though, so there is still
room for improvement in this.
See comments in fs/gfs2/ops_address.c for further information about
readpages with GFS2.
Signed-off-by: Steven Whitehouse
This patch contains the following possible cleanups:
- make needlessly global code static
- #if 0 unused functions
- remove the following global function that was both unused and
unimplemented:
- super.c: gfs2_do_upgrade()
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
1. Comment whitespace fix
2. Removed unused header files from dir.c
3. Split the gfs2_dir_get_buffer() function into two functions
Cc: Christoph Hellwig <hch@infradead.org>
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>
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>
This is a very large patch, with a few still to be resolved issues
so you might want to check out the previous head of the tree since
this is known to be unstable. Fixes for the various bugs will be
forthcoming shortly.
This patch removes the special data format which has been used
up till now for journaled data files. Directories still retain the
old format so that they will remain on disk compatible with earlier
releases. As a result you can now do the following with journaled
data files:
1) mmap them
2) export them over NFS
3) convert to/from normal files whenever you want to (the zero length
restriction is gone)
In addition the level at which GFS' locking is done has changed for all
files (since they all now use the page cache) such that the locking is
done at the page cache level rather than the level of the fs operations.
This should mean that things like loopback mounts and other things which
touch the page cache directly should now work.
Current known issues:
1. There is a lock mode inversion problem related to the resource
group hold function which needs to be resolved.
2. Any significant amount of I/O causes an oops with an offset of hex 320
(NULL pointer dereference) which appears to be related to a journaled data
buffer appearing on a list where it shouldn't be.
3. Direct I/O writes are disabled for the time being (will reappear later)
4. There is probably a deadlock between the page lock and GFS' locks under
certain combinations of mmap and fs operation I/O.
5. Issue relating to ref counting on internally used inodes causes a hang
on umount (discovered before this patch, and not fixed by it)
6. One part of the directory metadata is different from GFS1 and will need
to be resolved before next release.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Update the function in GFS2 which deals with truncation of
partial blocks. Some of the code is "borrowed" from ext3
since it appears to give a good model of how to do this
operation. The function is renamed gfs2_block_truncate_page
accordingly.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
For some reason a function pointer was being passed through
the truncate code which only ever took one value. This removes
the function pointer and replaces it with a single call to
the function in question.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This adds an extra argument to gfs2_trans_add_bh() to indicate whether the
bh being added to the transaction is metadata or data. Its currently unused
since all existing callers set it to 1 (metadata) but following patches will
make use of it.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch contains all the core files for GFS2.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Benjamin Marzinski
Steven Whitehouse
Cyrill Gorcunov
Bob Peterson
Christoph Lameter
Wendy Cheng
Nate Diller
Tim Schmielau
Eric Sandeen
Al Viro
Fabio Massimo Di Nitto
akpm@osdl.org
Jan Engelhardt
Adrian Bunk
Steven Whitehouse
Steven Whitehouse
David Teigland