This patch reduces GFS2 file fragmentation by pre-reserving blocks. The
resulting improved on disk layout greatly speeds up operations in cases
which would have resulted in interlaced allocation of blocks previously.
A typical example of this is 10 parallel dd processes, each writing to a
file in a common dirctory.

The implementation uses an rbtree of reservations attached to each
resource group (and each inode).
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

boolean "does it have to be exclusive?" flag is passed instead;
Local filesystem should just ignore it - the object is guaranteed
not to be there yet.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Just the flags; only NFS cares even about that, but there are
legitimate uses for such argument.  And getting rid of that
completely would require splitting ->lookup() into a couple
of methods (at least), so let's leave that alone for now...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This patch moves the ancillary quota data structures into the
block reservations structure. This saves GFS2 some time and
effort in allocating and deallocating the qadata structure.
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This patch lengthens the lifespan of the reservations structure for
inodes. Before, they were allocated and deallocated for every write
operation. With this patch, they are allocated when the first write
occurs, and deallocated when the last process closes the file.
It's more efficient to do it this way because it saves GFS2 a lot of
unnecessary allocates and frees. It also gives us more flexibility
for the future: (1) we can now fold the qadata structure back into
the structure and save those alloc/frees, (2) we can use this for
multi-block reservations.
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This patch removes the call from gfs2_blk2rgrd to function
gfs2_rindex_update and replaces it with individual calls.
The former way turned out to be too problematic.
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

The FITRIM ioctl provides an alternative way to send discard requests to
the underlying device. Using the discard mount option results in every
freed block generating a discard request to the block device. This can
be slow, since many block devices can only process discard requests of
larger sizes, and also such operations can be time consuming.

Rather than using the discard mount option, FITRIM allows a sweep of the
filesystem on an occasional basis, and also to optionally avoid sending
down discard requests for smaller regions.

In GFS2 FITRIM will work at resource group granularity. There is a flag
for each resource group which keeps track of which resource groups have
been trimmed. This flag is reset whenever a deallocation occurs in the
resource group, and set whenever a successful FITRIM of that resource
group has taken place. This helps to reduce repeated discard requests
for the same block ranges, again improving performance.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This makes mount take slightly longer, but at the same time, the first
write to the filesystem will be faster too. It also means that if there
is a problem in the resource index, then we can refuse to mount rather
than having to try and report that when the first write occurs.

In addition, to avoid recursive locking, we hvae to take account of
instances when the rindex glock may already be held when we are
trying to update the rbtree of resource groups.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This patch fixes a problem whereby you were unable to delete
files until other file system operations were done (such as
statfs, touch, writes, etc.) that caused the rindex to be
read in.
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Since the nlink count will be 0, we need to use set_nlink rather
than inc_nlink in order to avoid triggering the inc_nlink warning
which was added recently.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

vfs_create() ignores everything outside of 16bit subset of its
mode argument; switching it to umode_t is obviously equivalent
and it's the only caller of the method
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

vfs_mkdir() gets int, but immediately drops everything that might not
fit into umode_t and that's the only caller of ->mkdir()...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Quiets the sparse noise:

warning: symbol 'gfs2_initxattrs' was not declared. Should it be static?
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Clean up gfs2_alloc_blocks so that it takes the full extent length
rather than just the number of non-inode blocks as an argument. That
will only make a difference in the inode allocation case for now.

Also, this fixes the extent length handling around gfs2_alloc_extent() so
that multi block allocations will work again.

The rd_last_alloc block is set to the final block in the allocated
extent (as per the update to i_goal, but referenced to a different
start point).

This also removes the dinode argument to rgblk_search() which is no
longer used.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This patch separates the code pertaining to allocations into two
parts: quota-related information and block reservations.
This patch also moves all the block reservation structure allocations to
function gfs2_inplace_reserve to simplify the code, and moves
the frees to function gfs2_inplace_release.
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This patch is a revision of the one I previously posted.
I tried to integrate all the suggestions Steve gave.
The purpose of the patch is to change function gfs2_alloc_block
(allocate either a dinode block or an extent of data blocks)
to a more generic gfs2_alloc_blocks function that can
allocate both a dinode _and_ an extent of data blocks in the
same call. This will ultimately help us create a multi-block
reservation scheme to reduce file fragmentation.

This patch moves more toward a generic multi-block allocator that
takes a pointer to the number of data blocks to allocate, plus whether
or not to allocate a dinode. In theory, it could be called to allocate
(1) a single dinode block, (2) a group of one or more data blocks, or
(3) a dinode plus several data blocks.
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

GFS2 functions gfs2_alloc_block and gfs2_alloc_di do basically
the same things, with a few exceptions. This patch combines
the two functions into a slightly more generic gfs2_alloc_block.
Having one centralized block allocation function will reduce
code redundancy and make it easier to implement multi-block
reservations to reduce file fragmentation in the future.
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

A potentially uninitialised variable, some unreachable code,
and the main part of this, fixing the error path in the
unlink function.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This means that after the initial allocation for any inode, the
last used resource group is cached in the inode for future use.
This drastically reduces the number of lookups of resource
groups in the common case, and this the contention on that
data structure.

The allocation algorithm is the same as previously, except that we
always check to see if the goal block is within the cached rgrp
first before going to the rbtree to look one up.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Since we have ruled out supporting online filesystem shrink,
it is possible to make the resource group list append only
during the life of a super block. This gives several benefits:

Firstly, we only need to read new rindex elements as they are added
rather than needing to reread the whole rindex file each time one
element is added.

Secondly, the rindex glock can be held for much shorter periods of
time, and is completely removed from the fast path for allocations.
The lock is taken in shared mode only when updating the resource
groups when the first allocation occurs, and after a grow has
taken place.

Thirdly, this results in a reduction in code size, and everything
gets a lot simpler to understand in this area.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

If we pass through knowledge of whether the creation is intended to be
exclusive or not, then we can deal with that in gfs2_create_inode
and remove one set of locking. Also this removes the loop in
gfs2_create and simplifies the code a bit.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

The aim of this patch is to use the newly enhanced ->dirty_inode()
super block operation to deal with atime updates, rather than
piggy backing that code into ->write_inode() as is currently
done.

The net result is a simplification of the code in various places
and a reduction of the number of gfs2_dinode_out() calls since
this is now implied by ->dirty_inode().

Some of the mark_inode_dirty() calls have been moved under glocks
in order to take advantage of then being able to avoid locking in
->dirty_inode() when we already have suitable locks.

One consequence is that generic_write_end() now correctly deals
with file size updates, so that we do not need a separate check
for that afterwards. This also, indirectly, means that fdatasync
should work correctly on GFS2 - the current code always syncs the
metadata whether it needs to or not.

Has survived testing with postmark (with and without atime) and
also fsx.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

If we have got far enough through the inode allocation code
path that an inode has already been allocated, then we must
call iput to dispose of it, if an error occurs during a
later part of the process. This will always be the final iput
since there will be no other references to the inode.

Unlike when the inode has been unlinked, its block state will
be GFS2_BLKST_INODE rather than GFS2_BLKST_UNLINKED so we need
to skip the test in ->evict_inode() for this one case in order
to ensure that it will be deallocated correctly. This patch adds
a new flag in order to ensure that this will happen correctly.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Replace the ->check_acl method with a ->get_acl method that simply reads an
ACL from disk after having a cache miss.  This means we can replace the ACL
checking boilerplate code with a single implementation in namei.c.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

d_splice_alias() will DTRT when given NULL or ERR_PTR
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

not used by the instances anymore.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

redundant; all callers get it duplicated in mask & MAY_NOT_BLOCK and none of
them removes that bit.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

its value depends only on inode and does not change; we might as
well store it in ->i_op->check_acl and be done with that.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This patch changes the security_inode_init_security API by adding a
filesystem specific callback to write security extended attributes.
This change is in preparation for supporting the initialization of
multiple LSM xattrs and the EVM xattr.  Initially the callback function
walks an array of xattrs, writing each xattr separately, but could be
optimized to write multiple xattrs at once.

For existing security_inode_init_security() calls, which have not yet
been converted to use the new callback function, such as those in
reiserfs and ocfs2, this patch defines security_old_inode_init_security().
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>

Now that there are no longer any exceptions to the normal inode
creation code path, we can move the parts of the locking code
which were duplicated in mkdir/mknod/create/symlink into the
inode create function.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This moves the symlink specific parts of inode creation
into the function where we initialise the rest of the
dinode. As a result we have one less place where we need
to look up the inode's buffer.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This moves the initialisation of the directory into the inode
creation functions to avoid having to duplicate the lookup
of the inode's buffer.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This is the final part of the ops_inode.c/inode.c reordering. We
are left with a single file called inode.c which now contains
all the inode operations, as expected.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This is in preparation to remove inode.c and rename ops_inode.c
to inode.c. Also most of the functions which were left in inode.c
relate to the creation and lookup of inodes. I'm intending to work
on consolidating some of that code, and its easier when its all in
one place.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This function was intended for debugging purposes, but it is not very
useful. If we want to know what is on disk then all we need is a
block number and gfs2_edit can give us much better information about
what is there. Otherwise, if we are interested in what is stored in
the in-core inode, it doesn't help us out there either.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This adds an increment of the link count when we add a new directory
entry, if that entry is itself a directory. This means that we no
longer need separate code to perform this operation.

Now that both adding and removing directory entries automatically
update the parent directory's link count if required, that makes
the code shorter and simpler than before.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

When we remove an entry from a directory, we can save ourselves
some trouble if we know the type of the entry in question, since
if it is itself a directory, we can update the link count of the
parent at the same time as removing the directory entry.

In addition this patch also merges the rmdir and unlink code which
was almost identical anyway. This eliminates the calls to remove
the . and .. directory entries on each rmdir (not needed since the
directory will be deallocated, anyway) which was the only thing preventing
passing the dentry to gfs2_dir_del(). The passing of the dentry
rather than just the name allows us to figure out the type of the entry
which is being removed, and thus adjust the link count when required.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

There are three users of gfs2_change_nlink which add to the link
count. Two of these are about to be removed in later patches, so
this means that there will no callers, when that happens allowing
removal of that function, also in a later patch.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>