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This patch basically reverts the majority of patch 5407e242

.
That patch eliminated the gfs2_qadata structure in favor of just
using the reservations structure. The problem with doing that is that
it increases the size of the reservations structure. That is not an
issue until it comes time to fold the reservations structure into the
inode in memory so we know it's always there. By separating out the
quota structure again, we aren't punishing the non-quota users by
making all the inodes bigger, requiring more slab space. This patch
creates a new slab area to allocate the quota stuff so it's managed
a little more sanely.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

When new files and directories are created inside a parent directory
we automatically inherit the GFS2_DIF_SYSTEM flag (if set) and assign
it to the new file/dirs.

All new system files/dirs created in the metafs by, say gfs2_jadd,
will have this flag set because they will have parent directories in
the metafs whose GFS2_DIF_SYSTEM flag has already been set (most likely
by a previous mkfs.gfs2)
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

For smaller block sizes (512B, 1K, 2K), some quotas straddle block
boundaries such that the usage value is on one block and the rest
of the quota is on the previous block. In such cases, the value
does not get updated correctly. This patch fixes that by addressing
the boundary conditions correctly.

This patch also adds a (s64) cast that was missing in a call to
gfs2_quota_change() in inode.c
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

its only use is getting passed to nd_jump_link(), which can obtain
it from current->nameidata
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

a) instead of storing the symlink body (via nd_set_link()) and returning
an opaque pointer later passed to ->put_link(), ->follow_link() _stores_
that opaque pointer (into void * passed by address by caller) and returns
the symlink body.  Returning ERR_PTR() on error, NULL on jump (procfs magic
symlinks) and pointer to symlink body for normal symlinks.  Stored pointer
is ignored in all cases except the last one.

Storing NULL for opaque pointer (or not storing it at all) means no call
of ->put_link().

b) the body used to be passed to ->put_link() implicitly (via nameidata).
Now only the opaque pointer is.  In the cases when we used the symlink body
to free stuff, ->follow_link() now should store it as opaque pointer in addition
to returning it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

gfs2 now uses the rename2 directory iop, and supports the
RENAME_EXCHANGE flag (as well as RENAME_NOREPLACE, which the vfs
takes care of).

Signed-off-by: Benjamin Marzinski <bmarzins redhat com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

Follow the same style used for the other functions in the same file.
Signed-off-by: Antonio Ospite <ao2@ao2.it>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

that's the bulk of filesystem drivers dealing with inodes of their own
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Use struct gfs2_alloc_parms as an argument to gfs2_quota_check()
and gfs2_quota_lock_check() to check for quota violations while
accounting for the new blocks requested by the current operation
in ap->target.

Previously, the number of new blocks requested during an operation
were not accounted for during quota_check and would allow these
operations to exceed quota. This was not very apparent since most
operations allocated only 1 block at a time and quotas would get
violated in the next operation. i.e. quota excess would only be by
1 block or so. With fallocate, (where we allocate a bunch of blocks
at once) the quota excess is non-trivial and is addressed by this
patch.
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>

This patch just removes a goto that did nothing.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

In ->atomic_open(inode, dentry, file, opened) calling finish_no_open(file, NULL)
is equivalent to dget(dentry); return finish_no_open(file, dentry);

No need to open-code that...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

dentry is always hashed and negative, inode - non-error, non-NULL and
non-directory.  In such conditions d_splice_alias() is equivalent to
"d_instantiate(dentry, inode) and return NULL", which simplifies the
downstream code and is consistent with the "have to create a new object"
case.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

In ->atomic_open(inode, dentry, file, opened) calling finish_no_open(file, NULL)
is equivalent to dget(dentry); return finish_no_open(file, dentry);

No need to open-code that...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

dentry is always hashed and negative, inode - non-error, non-NULL and
non-directory.  In such conditions d_splice_alias() is equivalent to
"d_instantiate(dentry, inode) and return NULL", which simplifies the
downstream code and is consistent with the "have to create a new object"
case.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

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

The current gfs2 freezing code is considerably more complicated than it
should be because it doesn't use the vfs freezing code on any node except
the one that begins the freeze.  This is because it needs to acquire a
cluster glock before calling the vfs code to prevent a deadlock, and
without the new freeze_super and thaw_super hooks, that was impossible. To
deal with the issue, gfs2 had to do some hacky locking tricks to make sure
that a frozen node couldn't be holding on a lock it needed to do the
unfreeze ioctl.

This patch makes use of the new hooks to simply the gfs2 locking code. Now,
all the nodes in the cluster freeze and thaw in exactly the same way. Every
node in the cluster caches the freeze glock in the shared state.  The new
freeze_super hook allows the freezing node to grab this freeze glock in
the exclusive state without first calling the vfs freeze_super function.
All the nodes in the cluster see this lock change, and call the vfs
freeze_super function. The vfs locking code guarantees that the nodes can't
get stuck holding the glocks necessary to unfreeze the system.  To
unfreeze, the freezing node uses the new thaw_super hook to drop the freeze
glock. Again, all the nodes notice this, reacquire the glock in shared mode
and call the vfs thaw_super function.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

No need to store gfs2_dir_check result and test it before returning.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

hashed dentry can be passed to ->atomic_open() only if
a) it has just passed revalidation and
b) it's negative
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

This patch fixes a regression in the patch "GFS2: Remember directory
insert point", commit 2b47dad8

.
The problem had to do with the rename function: The function found
space for the new dirent, and remembered that location. But then the
old dirent was removed, which often moved the eligible location for
the renamed dirent. Putting the new dirent at the saved location
caused file system corruption.

This patch adds a new "save_loc" variable to struct gfs2_diradd.
If 1, the dirent location is saved. If 0, the dirent location is not
saved and the buffer_head is released as per previous behavior.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

This patch checks if i_goal is either zero or if doesn't exist
within any rgrp (i.e gfs2_blk2rgrpd() returns NULL). If so, it
assigns the ip->i_no_addr block as the i_goal.

There are two scenarios where a bad i_goal can result in a
-EBADSLT error.

1. Attempting to allocate to an existing inode:
Control reaches gfs2_inplace_reserve() and ip->i_goal is bad.
We need to fix i_goal here.

2. A new inode is created in a directory whose i_goal is hosed:
In this case, the parent dir's i_goal is copied onto the new
inode. Since the new inode is not yet created, the ip->i_no_addr
field is invalid and so, the fix in gfs2_inplace_reserve() as per
1) won't work in this scenario. We need to catch and fix it sooner
in the parent dir itself (gfs2_create_inode()), before it is
copied to the new inode.
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

Callers of d_splice_alias(dentry, inode) don't need iput(), neither
on success nor on failure.  Either the reference to inode is stored
in a previously negative dentry, or it's dropped.  In either case
inode reference the caller used to hold is consumed.

__gfs2_lookup() does iput() in case when d_splice_alias() has failed.
Double iput() if we ever hit that.  And gfs2_create_inode() ends up
not only with double iput(), but with link count dropped to zero - on
an inode it has just found in directory.

Cc: stable@vger.kernel.org # v3.14+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

Fix a regression introduced by:
6d4ade98

 GFS2: Add atomic_open support
where an early return misses d_splice_alias() which had been
adding the negative dentry.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2 has a transaction glock, which must be grabbed for every
transaction, whose purpose is to deal with freezing the filesystem.
Aside from this involving a large amount of locking, it is very easy to
make the current fsfreeze code hang on unfreezing.

This patch rewrites how gfs2 handles freezing the filesystem. The
transaction glock is removed. In it's place is a freeze glock, which is
cached (but not held) in a shared state by every node in the cluster
when the filesystem is mounted. This lock only needs to be grabbed on
freezing, and actions which need to be safe from freezing, like
recovery.

When a node wants to freeze the filesystem, it grabs this glock
exclusively.  When the freeze glock state changes on the nodes (either
from shared to unlocked, or shared to exclusive), the filesystem does a
special log flush.  gfs2_log_flush() does all the work for flushing out
the and shutting down the incore log, and then it tries to grab the
freeze glock in a shared state again.  Since the filesystem is stuck in
gfs2_log_flush, no new transaction can start, and nothing can be written
to disk. Unfreezing the filesytem simply involes dropping the freeze
glock, allowing gfs2_log_flush() to grab and then release the shared
lock, so it is cached for next time.

However, in order for the unfreezing ioctl to occur, gfs2 needs to get a
shared lock on the filesystem root directory inode to check permissions.
If that glock has already been grabbed exclusively, fsfreeze will be
unable to get the shared lock and unfreeze the filesystem.

In order to allow the unfreeze, this patch makes gfs2 grab a shared lock
on the filesystem root directory during the freeze, and hold it until it
unfreezes the filesystem.  The functions which need to grab a shared
lock in order to allow the unfreeze ioctl to be issued now use the lock
grabbed by the freeze code instead.

The freeze and unfreeze code take care to make sure that this shared
lock will not be dropped while another process is using it.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

When gfs2_create_inode() fails due to quota violation, the VFS
inode is not completely uninitialized. This can cause a list
corruption error.

This patch correctly uninitializes the VFS inode when a quota
violation occurs in the gfs2_create_inode codepath.

Resolves: rhbz#1059808
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

This patch eliminates function gfs2_security_init in favor of just
calling security_inode_init_security directly.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

gfs2_lookupi() can return NULL if the path to the root is broken by
another rename/rmdir. In this case gfs2_ok_to_move() must check for
this NULL pointer and return error.

Resolves: rhbz#1060246
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

This is another step towards improving the allocation of xattr
blocks at inode allocation time. Here we take advantage of
Christoph's recent work on ACLs to allocate a block for the
xattrs early if we know that we will be adding ACLs to the
inode later on. The advantage of that is that it is much
more likely that we'll get a contiguous run of two blocks
where the first is the inode and the second is the xattr block.

We still have to fall back to the original system in case we
don't get the requested two contiguous blocks, or in case the
ACLs are too large to fit into the block.

Future patches will move more of the ACL setting code further
up the gfs2_inode_create() function. Also, I'd like to be
able to do the same thing with the xattrs from LSMs in
due course, too. That way we should be able to slowly reduce
the number of independent transactions, at least in the
most common cases.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

This contains some major refactoring for the create path so that
inodes are created with the right mode to start with instead of
fixing it up later.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

0d0d1107

 asserts that "d_splice_alias()
can't return error unless it was given an IS_ERR(inode)".

That was true of the implementation of d_splice_alias, but this is
really a problem with d_splice_alias: at a minimum it should be able to
return -ELOOP in the case where inserting the given dentry would cause a
directory loop.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

Al Viro has tactfully pointed out that we are using the incorrect
error code in some cases. This patch fixes that, and also removes
the (unused) return value for glock dumping.

>        * gfs2_iget() - ENOBUFS instead of ENOMEM.  ENOBUFS is
> "No buffer space available (POSIX.1 (XSI STREAMS option))" and since
> we don't support STREAMS it's probably fair game, but... what the hell?
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>

This patch calls get_write_access in function gfs2_setattr_chown,
which merely increases inode->i_writecount for the duration of the
function. That will ensure that any file closes won't delete the
inode's multi-block reservation while the function is running.
It also ensures that a multi-block reservation exists when needed
for quota change operations during the chown.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

When we look to see if there is enough space to add a dir
entry without allocation, we have then been repeating the
same search later when we do the actual insertion. This
patch caches the details of the location in the gfs2_diradd
structure, so that we do not have to repeat the search.

This will provide a performance improvement which will be
greater as the size of the directory increases.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

There are three cases where we need to calculate the number of
blocks to reserve in a transaction involving linking an inode
into a directory. The one in rename is a bit more complicated,
but the basis of it is the same as for link and create. So it
makes sense to move this calculation into a single function
rather than repeating it three times.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

The intent is that this structure will hold the information
required when adding entries to a directory (linking). To
start with, it will contain only the number of blocks which
are required to link the new entry into the directory. The
current calculation returns either 0 or the maximim number of
blocks that can ever be requested by such a transaction.

The intent is that in a later patch, we can update the dir
code to calculate this value more accurately. In addition
further patches will also add further fields to the new
structure to increase its utility.

In addition this patch fixes a bug where the link used during
inode creation was adding requesting too many blocks in
some cases. This is harmless unless the fs is close to being
full.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

In the case that atomic_open calls finish_no_open() with
the dentry that was supplied to gfs2_atomic_open() an
extra reference count is required. This patch fixes that
issue preventing a bug trap triggering at umount time.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

duplicated to hell and back...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

This patch adds a structure to contain allocation parameters with
the intention of future expansion of this structure. The idea is
that we should be able to add more information about the allocation
in the future in order to allow the allocator to make a better job
of placing the requests on-disk.

There is no functional difference from applying this patch.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

The reservation for an inode should be cleared when it is truncated so
that we can start again at a different offset for future allocations.
We could try and do better than that, by resetting the search based on
where the truncation started from, but this is only a first step.

In addition, there are three callers of gfs2_rs_delete() but only one
of those should really be testing the value of i_writecount. While
we get away with that in the other cases currently, I think it would
be better if we made that test specific to the one case which
requires it.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

We need to dput() the result of d_splice_alias(), unless it is passed to
finish_no_open().

Edited by Steven Whitehouse in order to make it apply to the current
GFS2 git tree, and taking account of a prerequisite patch which hasn't
been applied.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: stable@vger.kernel.org