This patch adds code to function trans_drain to remove drained
bd elements from the ail lists, if queued, before freeing the bd.
If we don't remove the bd from the ail, function ail_drain will
try to reference the bd after it has been freed by trans_drain.
Thanks to Andy Price for his analysis of the problem.
Reported-by: Andy Price <anprice@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
In the log, revokes are stored as a revoke descriptor (struct
gfs2_log_descriptor), followed by zero or more additional revoke blocks
(struct gfs2_meta_header). On filesystems with a blocksize of 4k, the
revoke descriptor contains up to 503 revokes, and the metadata blocks
contain up to 509 revokes each. We've so far been reserving space for
revokes in transactions in block granularity, so a lot more space than
necessary was being allocated and then released again.
This patch switches to assigning revokes to transactions individually
instead. Initially, space for the revoke descriptor is reserved and
handed out to transactions. When more revokes than that are reserved,
additional revoke blocks are added. When the log is flushed, the space
for the additional revoke blocks is released, but we keep the space for
the revoke descriptor block allocated.
Transactions may still reserve more revokes than they will actually need
in the end, but now we won't overshoot the target as much, and by only
returning the space for excess revokes at log flush time, we further
reduce the amount of contention between processes.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
The current log space allocation logic is hard to understand or extend.
The principle it that when the log is flushed, we may or may not have a
transaction active that has space allocated in the log. To deal with
that, we set aside a magical number of blocks to be used in case we
don't have an active transaction. It isn't clear that the pool will
always be big enough. In addition, we can't return unused log space at
the end of a transaction, so the number of blocks allocated must exactly
match the number of blocks used.
Simplify this as follows:
* When transactions are allocated or merged, always reserve enough
blocks to flush the transaction (err on the safe side).
* In gfs2_log_flush, return any allocated blocks that haven't been used.
* Maintain a pool of spare blocks big enough to do one log flush, as
before.
* In gfs2_log_flush, when we have no active transaction, allocate a
suitable number of blocks. For that, use the spare pool when
called from logd, and leave the pool alone otherwise. This means
that when the log is almost full, logd will still be able to do one
more log flush, which will result in more log space becoming
available.
This will make the log space allocator code easier to work with in
the future.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Use a tighter bound for the number of blocks required by transactions in
gfs2_trans_begin: in the worst case, we'll have mixed data and metadata,
so we'll need a log desciptor for each type.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Wake up log waiters in gfs2_log_release when log space has actually become
available. This is a much better place for the wakeup than gfs2_logd.
Check if enough log space is immeditely available before anything else. If
there isn't, use io_wait_event to wait instead of open-coding it.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Move the read locking of sd_log_flush_lock from gfs2_log_reserve to
gfs2_trans_begin, and its unlocking from gfs2_log_release to
gfs2_trans_end. Use gfs2_log_release in two places in which it was open
coded before.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This counter and the associated wait queue are only used so that
gfs2_make_fs_ro can efficiently wait for all pending log space
allocations to fail after setting the filesystem to read-only. This
comes at the cost of waking up that wait queue very frequently.
Instead, when gfs2_log_reserve fails because the filesystem has become
read-only, Wake up sd_log_waitq. In gfs2_make_fs_ro, set the file
system read-only and then wait until all the log space has been
released. Give up and report the problem after a while. With that,
sd_reserving_log and sd_reserving_log_wait can be removed.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Replace the TR_ALLOCED flag by its inverse, TR_ONSTACK: that way, the flag only
needs to be set in the exceptional case of on-stack transactions. Split off
__gfs2_trans_begin from gfs2_trans_begin and use it to replace the open-coded
version in gfs2_ail_empty_gl.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Commit 2e60d7683c ("GFS2: update freeze code to use freeze/thaw_super
on all nodes") optimized away the sb_start_intwrite ... sb_end_intwrite
protection for the on-stack transactions in gfs2_ail_empty_gl with no
explanation. I can't think of a valid reason for doing that, so revert
that change. This simplifies the next commit.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
When a log flush fails due to io errors, it signals the failure but does
not clean up after itself very well. This is because buffers are added to
the transaction tr_buf and tr_databuf queue, but the io error causes
gfs2_log_flush to bypass the "after_commit" functions responsible for
dequeueing the bd elements. If the bd elements are added to the ail list
before the error, function ail_drain takes care of dequeueing them.
But if they haven't gotten that far, the elements are forgotten and
make the transactions unable to be freed.
This patch introduces new function trans_drain which drains the bd
elements from the transaction so they can be freed properly.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
If function gfs2_trans_begin is called with another transaction active
it BUGs out, but it doesn't give any details about the duplicate.
This patch moves function gfs2_print_trans and calls it when this
situation arises for better debugging.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch adds a new slab for gfs2 transactions. That allows us to
reduce kernel memory fragmentation, have better organization of data
for analysis of vmcore dumps. A new centralized function is added to
free the slab objects, and it exposes use-after-free by giving
warnings if a transaction is freed while it still has bd elements
attached to its buffers or ail lists. We make sure to initialize
those transaction ail lists so we can check their integrity when freeing.
At a later time, we should add a slab initialization function to
make it more efficient, but for this initial patch I wanted to
minimize the impact.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Since transactions may be freed shortly after they're created, before
a log_flush occurs, we need to initialize their ail1 and ail2 lists
earlier. Before this patch, the ail1 list was initialized in gfs2_log_flush().
This moves the initialization to the point when the transaction is first
created.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Before this patch, gfs2_logd continually tried to flush its journal
log, after the file system is withdrawn. We don't want to write anything
to the journal, lest we add corruption. Best course of action is to
drain the ail1 into the ail2 list (via gfs2_ail1_empty) then drain the
ail2 list with a new function, ail2_drain.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
This reverts commit e955537e32.
Before patch e955537e32, tr_num_revoke tracked the number of revokes
added to the transaction, and tr_num_revoke_rm tracked how many
revokes were removed. But since revokes are queued off the sdp
(superblock) pointer, some transactions could remove more revokes
than they added. (e.g. revokes added by a different process).
Commit e955537e32 eliminated transaction variable tr_num_revoke_rm,
but in order to do so, it changed the accounting to always use
tr_num_revoke for its math. Since you can remove more revokes than
you add, tr_num_revoke could now become a negative value.
This negative value broke the assert in function gfs2_trans_end:
if (gfs2_assert_withdraw(sdp, (nbuf <=3D tr->tr_blocks) &&
(tr->tr_num_revoke <=3D tr->tr_revokes)))
One way to fix this is to simply remove the tr_num_revoke clause
from the assert and allow the value to become negative. Andreas
didn't like that idea, so instead, we decided to revert e955537e32.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Every caller of function gfs2_struct2blk specified sizeof(u64).
This patch eliminates the unnecessary parameter and replaces the
size calculation with a new superblock variable that is computed
to be the maximum number of block pointers we can fit inside a
log descriptor, as is done for pointers per dinode and indirect
block.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Commit 9287c6452d fixed a situation in which gfs2 could use a glock
after it had been freed. To do that, it temporarily added a new glock
reference by calling gfs2_glock_hold in function gfs2_add_revoke.
However, if the bd element was removed by gfs2_trans_remove_revoke, it
failed to drop the additional reference.
This patch adds logic to gfs2_trans_remove_revoke to properly drop the
additional glock reference.
Fixes: 9287c6452d ("gfs2: Fix occasional glock use-after-free")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
For its journal processing, gfs2 kept track of the number of buffers
added and removed on a per-transaction basis. These values are used
to calculate space needed in the journal. But while these calculations
make sense for the number of buffers, they make no sense for revokes.
Revokes are managed in their own list, linked from the superblock.
So it's entirely unnecessary to keep separate per-transaction counts
for revokes added and removed. A single count will do the same job.
Therefore, this patch combines the transaction revokes into a single
count.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Based on 1 normalized pattern(s):
this copyrighted material is made available to anyone wishing to use
modify copy or redistribute it subject to the terms and conditions
of the gnu general public license version 2
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 44 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531081038.653000175@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Rename gfs2_trans_add_unrevoke to gfs2_trans_remove_revoke: there is no
such thing as an "unrevoke" object; all this function does is remove
existing revoke objects plus some bookkeeping.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Rename sd_log_le_revoke to sd_log_revokes and sd_log_le_ordered to
sd_log_ordered: not sure what le stands for here, but it doesn't add
clarity, and if it stands for list entry, it's actually confusing as
those are both list heads but not list entries.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Field bd_ops was set but never used, so I removed it, and all
code supporting it.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Before this patch, various errors and messages were reported using
the pr_* functions: pr_err, pr_warn, pr_info, etc., but that does
not tell you which gfs2 mount had the problem, which is often vital
to debugging. This patch changes the calls from pr_* to fs_* in
most of the messages so that the file system id is printed along
with the message.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
In journaled data mode, we need to add each buffer head to the current
transaction. In ordered write mode, we only need to add the inode to
the ordered inode list. So far, both cases are handled in
gfs2_trans_add_data. This makes the code look misleading and is
inefficient for small block sizes as well. Handle both cases separately
instead.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This patch just adds the capability for GFS2 to track which function
called gfs2_log_flush. This should make it easier to diagnose
problems based on the sequence of events found in the journals.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch adds a new structure called gfs2_log_header_v2 which is used
to store expanded fields into previously unused areas of the log headers
(i.e., this change is backwards compatible). Some of these are used for
debug purposes so we can backtrack when problems occur. Others are
reserved for future expansion.
This patch is based on a prototype from Steve Whitehouse.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
The current transaction is being dereferenced before asserting that is
not NULL; that isn't going to help.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This is a pure automated search-and-replace of the internal kernel
superblock flags.
The s_flags are now called SB_*, with the names and the values for the
moment mirroring the MS_* flags that they're equivalent to.
Note how the MS_xyz flags are the ones passed to the mount system call,
while the SB_xyz flags are what we then use in sb->s_flags.
The script to do this was:
# places to look in; re security/*: it generally should *not* be
# touched (that stuff parses mount(2) arguments directly), but
# there are two places where we really deal with superblock flags.
FILES="drivers/mtd drivers/staging/lustre fs ipc mm \
include/linux/fs.h include/uapi/linux/bfs_fs.h \
security/apparmor/apparmorfs.c security/apparmor/include/lib.h"
# the list of MS_... constants
SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \
DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \
POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \
I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \
ACTIVE NOUSER"
SED_PROG=
for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done
# we want files that contain at least one of MS_...,
# with fs/namespace.c and fs/pnode.c excluded.
L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c')
for f in $L; do sed -i $f $SED_PROG; done
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch modifies functions gfs2_trans_add_meta and _data so that
they check whether the buffer_head is already in a transaction,
and if so, avoid taking the gfs2_log_lock.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This patch simply combines function meta_lo_add with its only
caller, trans_add_meta. This makes the code easier to read and
will make it easier to reduce contention on gfs2_log_lock.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This patch eliminates the int variable tr_touched in favor of a
new flag in the transaction. This is a step toward reducing contention
on the gfs2_log_lock spin_lock.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This patch fixes a timing window that causes a segfault.
The problem is that bd can remain NULL throughout the function
and then reference that NULL pointer if the bh->b_private starts
out NULL, then someone sets it to non-NULL inside the locking.
In that case, bd still needs to be set.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
What uniquely identifies a glock in the glock hash table is not
gl_name, but gl_name and its superblock pointer. This patch makes
the gl_name field correspond to a unique glock identifier. That will
allow us to simplify hashing with a future patch, since the hash
algorithm can then take the gl_name and hash its components in one
operation.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
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>
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>
Add pr_fmt, remove embedded "GFS2: " prefixes.
This now consistently emits lower case "gfs2: " for each message.
Other miscellanea around these changes:
o Add missing newlines
o Coalesce formats
o Realign arguments
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
-All printk(KERN_foo converted to pr_foo().
-Messages updated to fit in 80 columns.
-fs_macros converted as well.
-fs_printk removed.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Now we have a master transaction into which other transactions
are merged, the accounting can be done using this master
transaction. We no longer require the superblock fields which
were being used for this function.
In addition, this allows for a clean up in calc_reserved()
making it rather easier understand. Also, by reducing the
number of variables used to track the buffers being added
and removed from the journal, a number of error checks are
now no longer required.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Over time, we hope to be able to improve the concurrency available
in the log code. This is one small step towards that, by moving
the buffer lists from the super block, and into the transaction
structure, so that each transaction builds its own buffer lists.
At transaction commit time, the buffer lists are merged into
the currently accumulating transaction. That transaction then
is passed into the before and after commit functions at journal
flush time. Thus there should be no change in overall behaviour
yet.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
A couple of "int" fields were being used as boolean values
so we can make them bitfields of one bit, and put them in
what might otherwise be a hole in the structure with 64
bit alignment.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch fixes a warning message introduced in the recent
"GFS2: aggressively issue revokes in gfs2_log_flush" patch.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch looks at all the outstanding blocks in all the transactions
on the log, and moves the completed ones to the ail2 list. Then it
issues revokes for these blocks. This will hopefully speed things up
in situations where there is a lot of contention for glocks, especially
if they are acquired serially.
revoke_lo_before_commit will issue at most one log block's full of these
preemptive revokes. The amount of reserved log space that
gfs2_log_reserve() ignores has been incremented to allow for this extra
block.
This patch also consolidates the common revoke instructions into one
function, gfs2_add_revoke().
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Pull GFS2 updates from Steven Whitehouse:
"There is not a whole lot of change this time - there are some further
changes which are in the works, but those will be held over until next
time.
Here there are some clean ups to inode creation, the addition of an
origin (local or remote) indicator to glock demote requests, removal
of one of the remaining GFP_NOFAIL allocations during log flushes, one
minor clean up, and a one liner bug fix."
* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw:
GFS2: Flush work queue before clearing glock hash tables
GFS2: Add origin indicator to glock demote tracing
GFS2: Add origin indicator to glock callbacks
GFS2: replace gfs2_ail structure with gfs2_trans
GFS2: Remove vestigial parameter ip from function rs_deltree
GFS2: Use gfs2_dinode_out() in the inode create path
GFS2: Remove gfs2_refresh_inode from inode creation path
GFS2: Clean up inode creation path
Use the new vsprintf extension to avoid any possible
message interleaving.
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
In order to allow transactions and log flushes to happen at the same
time, gfs2 needs to move the transaction accounting and active items
list code into the gfs2_trans structure. As a first step toward this,
this patch removes the gfs2_ail structure, and handles the active items
list in the gfs_trans structure. This keeps gfs2 from allocating an ail
structure on log flushes, and gives us a struture that can later be used
to store the transaction accounting outside of the gfs2 superblock
structure.
With this patch, at the end of a transaction, gfs2 will add the
gfs2_trans structure to the superblock if there is not one already.
This structure now has the active items fields that were previously in
gfs2_ail. This is not necessary in the case where the transaction was
simply used to add revokes, since these are never written outside of the
journal, and thus, don't need an active items list.
Also, in order to make sure that the transaction structure is not
removed while it's still in use by gfs2_trans_end, unlocking the
sd_log_flush_lock has to happen slightly later in ending the
transaction.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Instead of using a list of buffers to write ahead of the journal
flush, this now uses a list of inodes and calls ->writepages
via filemap_fdatawrite() in order to achieve the same thing. For
most use cases this results in a shorter ordered write list,
as well as much larger i/os being issued.
The ordered write list is sorted by inode number before writing
in order to retain the disk block ordering between inodes as
per the previous code.
The previous ordered write code used to conflict in its assumptions
about how to write out the disk blocks with mpage_writepages()
so that with this updated version we can also use mpage_writepages()
for GFS2's ordered write, writepages implementation. So we will
also send larger i/os from writeback too.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
The locking in gfs2_attach_bufdata() was type specific (data/meta)
which made the function rather confusing. This patch moves the core
of gfs2_attach_bufdata() into trans.c renaming it gfs2_alloc_bufdata()
and moving the locking into gfs2_trans_add_data()/gfs2_trans_add_meta()
As a result all of the locking related to adding data and metadata to
the journal is now in these two functions. This should help to clarify
what is going on, and give us some opportunities to simplify in
some cases.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
