GFS2: Sort buffer lists by inplace block number

This patch simply sort the data and metadata buffer lists by their
inplace block number. This makes gfs2_log_flush issue the inplace IO
in sequential

GFS2: Sort buffer lists by inplace block number

This patch simply sort the data and metadata buffer lists by their
inplace block number. This makes gfs2_log_flush issue the inplace IO
in sequential order, which will hopefully speed up writing the IO
out to disk.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

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GFS2: Set log descriptor type for jdata blocks

This patch sets the log descriptor type according to whether the
journal commit is for (journaled) data or metadata. This was
recently broken when the

GFS2: Set log descriptor type for jdata blocks

This patch sets the log descriptor type according to whether the
journal commit is for (journaled) data or metadata. This was
recently broken when the functions to process data and metadata
log ops were combined.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

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GFS2: Fix typo in gfs2_log_end_write loop

There was a missing _all in this loop iterator

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: replace gfs2_ail structure with gfs2_trans

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 i

GFS2: replace gfs2_ail structure with gfs2_trans

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>

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block: Add bio_end_sector()

Just a little convenience macro - main reason to add it now is preparing
for immutable bio vecs, it'll reduce the size of the patch that puts
bi_sector/bi_size/bi_idx int

block: Add bio_end_sector()

Just a little convenience macro - main reason to add it now is preparing
for immutable bio vecs, it'll reduce the size of the patch that puts
bi_sector/bi_size/bi_idx into a struct bvec_iter.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: Lars Ellenberg <drbd-dev@lists.linbit.com>
CC: Jiri Kosina <jkosina@suse.cz>
CC: Alasdair Kergon <agk@redhat.com>
CC: dm-devel@redhat.com
CC: Neil Brown <neilb@suse.de>
CC: Martin Schwidefsky <schwidefsky@de.ibm.com>
CC: Heiko Carstens <heiko.carstens@de.ibm.com>
CC: linux-s390@vger.kernel.org
CC: Chris Mason <chris.mason@fusionio.com>
CC: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>

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GFS2: Copy gfs2_trans_add_bh into new data/meta functions

This patch copies the body of gfs2_trans_add_bh into the two newly
added gfs2_trans_add_data and gfs2_trans_add_meta functions. We can
then

GFS2: Copy gfs2_trans_add_bh into new data/meta functions

This patch copies the body of gfs2_trans_add_bh into the two newly
added gfs2_trans_add_data and gfs2_trans_add_meta functions. We can
then move the .lo_add functions from lops.c into trans.c and call
them directly.

As a result of this, we no longer need to use the .lo_add functions
at all, so that is removed from the log operations structure.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

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GFS2: Merge revoke adding functions

This moves the lo_add function for revokes into trans.c, removing
a function call and making the code easier to read.

Signed-off-by: Steven Whitehouse <swhiteho@

GFS2: Merge revoke adding functions

This moves the lo_add function for revokes into trans.c, removing
a function call and making the code easier to read.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

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GFS2: Test bufdata with buffer locked and gfs2_log_lock held

In gfs2_trans_add_bh(), gfs2 was testing if a there was a bd attached to the
buffer without having the gfs2_log_lock held. It was then as

GFS2: Test bufdata with buffer locked and gfs2_log_lock held

In gfs2_trans_add_bh(), gfs2 was testing if a there was a bd attached to the
buffer without having the gfs2_log_lock held. It was then assuming it would
stay attached for the rest of the function. However, without either the log
lock being held of the buffer locked, __gfs2_ail_flush() could detach bd at any
time. This patch moves the locking before the test. If there isn't a bd
already attached, gfs2 can safely allocate one and attach it before locking.
There is no way that the newly allocated bd could be on the ail list,
and thus no way for __gfs2_ail_flush() to detach it.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

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GFS2: Clean up some unused assignments

Cleans up two cases where variables were assigned values but then never
used again.

Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Steven Whi

GFS2: Clean up some unused assignments

Cleans up two cases where variables were assigned values but then never
used again.

Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

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GFS2: Fix error handling when reading an invalid block from the journal

When we read an invalid block from the journal, we should not call
withdraw, but simply print a message and return an error. I

GFS2: Fix error handling when reading an invalid block from the journal

When we read an invalid block from the journal, we should not call
withdraw, but simply print a message and return an error. It is
up to the caller to then handle that error. In the case of mount
that means a failed mount, rather than a withdraw (requiring a
reboot). In the case of recovering another nodes journal then
we return an error via the uevent.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

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GFS2: eliminate log elements and simplify

This patch eliminates the gfs2_log_element data structure and
rolls its two components into the gfs2_bufdata. This makes the code
easier to understand and m

GFS2: eliminate log elements and simplify

This patch eliminates the gfs2_log_element data structure and
rolls its two components into the gfs2_bufdata. This makes the code
easier to understand and makes it easier to migrate to a rbtree
to keep the list sorted.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

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GFS2: Log code fixes

This patch removes a log lock from around atomic operation where
it is not needed, removes an unused variable, and also changes
a void pointer used incorrectly to a struct page

GFS2: Log code fixes

This patch removes a log lock from around atomic operation where
it is not needed, removes an unused variable, and also changes
a void pointer used incorrectly to a struct page pointer.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

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GFS2: Remove bd_list_tr

This is another clean up in the logging code. This per-transaction
list was largely unused. Its main function was to ensure that the
number of buffers in a transaction was co

GFS2: Remove bd_list_tr

This is another clean up in the logging code. This per-transaction
list was largely unused. Its main function was to ensure that the
number of buffers in a transaction was correct, however that counter
was only used to check the number of buffers in the bd_list_tr, plus
an assert at the end of each transaction. With the assert now changed
to use the calculated buffer counts, we can remove both bd_list_tr and
its associated counter.

This should make the code easier to understand as well as shrinking
a couple of structures.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

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GFS2: Remove duplicate log code

The main part of this patch merges the two functions used to
write metadata and data buffers to the log. Most of the code
is common between the two functions, so this

GFS2: Remove duplicate log code

The main part of this patch merges the two functions used to
write metadata and data buffers to the log. Most of the code
is common between the two functions, so this provides a nice
clean up, and makes the code more readable.

The gfs2_get_log_desc() function is also extended to take two more
arguments, and thus avoid having to set the length and data1
fields of this strucuture as a separate operation.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

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GFS2: Clean up log write code path

Prior to this patch, we have two ways of sending i/o to the log.
One of those is used when we need to allocate both the data
to be written itself and also a buffer

GFS2: Clean up log write code path

Prior to this patch, we have two ways of sending i/o to the log.
One of those is used when we need to allocate both the data
to be written itself and also a buffer head to submit it. This
is done via sb_getblk and friends. This is used mostly for writing
log headers.

The other method is used when writing blocks which have some
in-place counterpart. This is the case for all the metadata
blocks which are journalled, and when journaled data is in use,
for unescaped journalled data blocks.

This patch replaces both of those two methods, and about half
a dozen separate i/o submission points with a single i/o
submission function. We also go direct to bio rather than
using buffer heads, since this allows us to build i/o
requests of the maximum size for the block device in
question. It also reduces the memory required for flushing
the log, which can be very useful in low memory situations.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

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GFS2: Make gfs2_log_fake_buf() write the buffer too

Since we always write the buffer directly after this function
returns, we might as well merge it into here. This is a clean
up in preparation for

GFS2: Make gfs2_log_fake_buf() write the buffer too

Since we always write the buffer directly after this function
returns, we might as well merge it into here. This is a clean
up in preparation for some further updates to the log code
which are coming soon.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

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gfs2: remove the second argument of k[un]map_atomic()

Signed-off-by: Cong Wang <amwang@redhat.com>

GFS2: Remove a __GFP_NOFAIL allocation

In order to ensure that we've got enough buffer heads for flushing
the journal, the orignal code used __GFP_NOFAIL when performing
this allocation. Here we dis

GFS2: Remove a __GFP_NOFAIL allocation

In order to ensure that we've got enough buffer heads for flushing
the journal, the orignal code used __GFP_NOFAIL when performing
this allocation. Here we dispense with that in favour of using a
mempool. This should improve efficiency in low memory conditions
since flushing the journal is a good way to get memory back, we
don't want to be spinning, waiting on memory allocations. The
buffers which are allocated via this mempool are fairly short lived,
so that we'll recycle them pretty quickly.

Although there are other memory allocations which occur during the
journal flush process, this is the one which can potentially require
the most memory, so the most important one to fix.

The amount of memory reserved is a fixed amount, and we should not need
to scale it when there are a greater number of filesystems in use.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

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GFS2: FITRIM ioctl support

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 di

GFS2: FITRIM ioctl support

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: Steven Whitehouse <swhiteho@redhat.com>

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GFS2: Move two functions from log.c to lops.c

gfs2_log_get_buf() and gfs2_log_fake_buf() are both used
only in lops.c, so move them next to their callers and they
can then become static.

Signed-off

GFS2: Move two functions from log.c to lops.c

gfs2_log_get_buf() and gfs2_log_fake_buf() are both used
only in lops.c, so move them next to their callers and they
can then become static.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

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GFS2: Misc fixes

Some items picked up through automated code analysis. A few bits
of unreachable code and two unchecked return values.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Use rbtree for resource groups and clean up bitmap buffer ref count scheme

Here is an update of Bob's original rbtree patch which, in addition, also
resolves the rather strange ref counting th

GFS2: Use rbtree for resource groups and clean up bitmap buffer ref count scheme

Here is an update of Bob's original rbtree patch which, in addition, also
resolves the rather strange ref counting that was being done relating to
the bitmap blocks.

Originally we had a dual system for journaling resource groups. The metadata
blocks were journaled and also the rgrp itself was added to a list. The reason
for adding the rgrp to the list in the journal was so that the "repolish
clones" code could be run to update the free space, and potentially send any
discard requests when the log was flushed. This was done by comparing the
"cloned" bitmap with what had been written back on disk during the transaction
commit.

Due to this, there was a requirement to hang on to the rgrps' bitmap buffers
until the journal had been flushed. For that reason, there was a rather
complicated set up in the ->go_lock ->go_unlock functions for rgrps involving
both a mutex and a spinlock (the ->sd_rindex_spin) to maintain a reference
count on the buffers.

However, the journal maintains a reference count on the buffers anyway, since
they are being journaled as metadata buffers. So by moving the code which deals
with the post-journal accounting for bitmap blocks to the metadata journaling
code, we can entirely dispense with the rather strange buffer ref counting
scheme and also the requirement to journal the rgrps.

The net result of all this is that the ->sd_rindex_spin is left to do exactly
one job, and that is to look after the rbtree or rgrps.

This patch is designed to be a stepping stone towards using RCU for the rbtree
of resource groups, however the reduction in the number of uses of the
->sd_rindex_spin is likely to have benefits for multi-threaded workloads,
anyway.

The patch retains ->go_lock and ->go_unlock for rgrps, however these maybe also
be removed in future in favour of calling the functions directly where required
in the code. That will allow locking of resource groups without needing to
actually read them in - something that could be useful in speeding up statfs.

In the mean time though it is valid to dereference ->bi_bh only when the rgrp
is locked. This is basically the same rule as before, modulo the references not
being valid until the following journal flush.

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

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GFS2: Optimise glock lru and end of life inodes

The GLF_LRU flag introduced in the previous patch can be
used to check if a glock is on the lru list when a new
holder is queued and if so remove it,

GFS2: Optimise glock lru and end of life inodes

The GLF_LRU flag introduced in the previous patch can be
used to check if a glock is on the lru list when a new
holder is queued and if so remove it, without having first
to get the lru_lock.

The main purpose of this patch however is to optimise the
glocks left over when an inode at end of life is being
evicted. Previously such glocks were left with the GLF_LFLUSH
flag set, so that when reclaimed, each one required a log flush.
This patch resets the GLF_LFLUSH flag when there is nothing
left to flush thus preventing later log flushes as glocks are
reused or demoted.

In order to do this, we need to keep track of the number of
revokes which are outstanding, and also to clear the GLF_LFLUSH
bit after a log commit when only revokes have been processed.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

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GFS2: Alter point of entry to glock lru list for glocks with an address_space

Rather than allowing the glocks to be scheduled for possible
reclaim as soon as they have exited the journal, this patch

GFS2: Alter point of entry to glock lru list for glocks with an address_space

Rather than allowing the glocks to be scheduled for possible
reclaim as soon as they have exited the journal, this patch
delays their entry to the list until the glocks in question
are no longer in use.

This means that we will rely on the vm for writeback of all
dirty data and metadata from now on. When glocks are added
to the lru list they should be freeable much faster since all
the I/O required to free them should have already been completed.

This should lead to much better I/O patterns under low memory
conditions.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

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GFS2: Update to AIL list locking

The previous patch missed a couple of places where the AIL list
needed locking, so this fixes up those places, plus a comment
is corrected too.

Signed-off-by: Steve

GFS2: Update to AIL list locking

The previous patch missed a couple of places where the AIL list
needed locking, so this fixes up those places, plus a comment
is corrected too.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Chinner <dchinner@redhat.com>

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