2008-01-24 14:13:08 -07:00
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#include <linux/err.h>
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#include <linux/slab.h>
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2007-08-27 14:49:44 -06:00
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#include <linux/spinlock.h>
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2008-01-24 14:13:08 -07:00
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#include <linux/hardirq.h>
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2010-12-16 23:21:50 -07:00
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#include "ctree.h"
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2007-08-27 14:49:44 -06:00
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#include "extent_map.h"
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2016-03-10 02:26:59 -07:00
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#include "compression.h"
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2007-08-27 14:49:44 -06:00
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2007-09-10 17:58:16 -06:00
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2007-08-27 14:49:44 -06:00
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static struct kmem_cache *extent_map_cache;
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2007-11-27 09:16:35 -07:00
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2007-11-19 08:22:33 -07:00
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int __init extent_map_init(void)
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2007-08-27 14:49:44 -06:00
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{
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2012-09-07 03:00:48 -06:00
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extent_map_cache = kmem_cache_create("btrfs_extent_map",
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2009-04-13 07:33:09 -06:00
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sizeof(struct extent_map), 0,
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SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
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2007-11-19 08:22:33 -07:00
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if (!extent_map_cache)
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return -ENOMEM;
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return 0;
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2007-08-27 14:49:44 -06:00
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}
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2007-12-11 07:25:06 -07:00
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void extent_map_exit(void)
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2007-08-27 14:49:44 -06:00
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{
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2016-01-29 06:36:35 -07:00
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kmem_cache_destroy(extent_map_cache);
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2007-08-27 14:49:44 -06:00
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}
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2008-06-11 19:52:17 -06:00
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/**
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* extent_map_tree_init - initialize extent map tree
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* @tree: tree to initialize
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*
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* Initialize the extent tree @tree. Should be called for each new inode
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* or other user of the extent_map interface.
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*/
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2011-04-20 16:34:43 -06:00
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void extent_map_tree_init(struct extent_map_tree *tree)
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2007-08-27 14:49:44 -06:00
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{
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2010-02-23 12:43:04 -07:00
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tree->map = RB_ROOT;
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Btrfs: turbo charge fsync
At least for the vm workload. Currently on fsync we will
1) Truncate all items in the log tree for the given inode if they exist
and
2) Copy all items for a given inode into the log
The problem with this is that for things like VMs you can have lots of
extents from the fragmented writing behavior, and worst yet you may have
only modified a few extents, not the entire thing. This patch fixes this
problem by tracking which transid modified our extent, and then when we do
the tree logging we find all of the extents we've modified in our current
transaction, sort them and commit them. We also only truncate up to the
xattrs of the inode and copy that stuff in normally, and then just drop any
extents in the range we have that exist in the log already. Here are some
numbers of a 50 meg fio job that does random writes and fsync()s after every
write
Original Patched
SATA drive 82KB/s 140KB/s
Fusion drive 431KB/s 2532KB/s
So around 2-6 times faster depending on your hardware. There are a few
corner cases, for example if you truncate at all we have to do it the old
way since there is no way to be sure what is in the log is ok. This
probably could be done smarter, but if you write-fsync-truncate-write-fsync
you deserve what you get. All this work is in RAM of course so if your
inode gets evicted from cache and you read it in and fsync it we'll do it
the slow way if we are still in the same transaction that we last modified
the inode in.
The biggest cool part of this is that it requires no changes to the recovery
code, so if you fsync with this patch and crash and load an old kernel, it
will run the recovery and be a-ok. I have tested this pretty thoroughly
with an fsync tester and everything comes back fine, as well as xfstests.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 11:14:17 -06:00
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INIT_LIST_HEAD(&tree->modified_extents);
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2009-09-02 14:24:52 -06:00
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rwlock_init(&tree->lock);
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2007-08-27 14:49:44 -06:00
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}
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2008-06-11 19:52:17 -06:00
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/**
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* alloc_extent_map - allocate new extent map structure
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*
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* Allocate a new extent_map structure. The new structure is
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* returned with a reference count of one and needs to be
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* freed using free_extent_map()
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*/
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2011-04-20 16:48:27 -06:00
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struct extent_map *alloc_extent_map(void)
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2007-08-27 14:49:44 -06:00
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{
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struct extent_map *em;
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2012-10-11 14:54:30 -06:00
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em = kmem_cache_zalloc(extent_map_cache, GFP_NOFS);
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2011-02-13 17:45:29 -07:00
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if (!em)
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return NULL;
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2014-02-25 07:15:12 -07:00
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RB_CLEAR_NODE(&em->rb_node);
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2008-01-24 14:13:08 -07:00
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em->flags = 0;
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2010-12-16 23:21:50 -07:00
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em->compress_type = BTRFS_COMPRESS_NONE;
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Btrfs: turbo charge fsync
At least for the vm workload. Currently on fsync we will
1) Truncate all items in the log tree for the given inode if they exist
and
2) Copy all items for a given inode into the log
The problem with this is that for things like VMs you can have lots of
extents from the fragmented writing behavior, and worst yet you may have
only modified a few extents, not the entire thing. This patch fixes this
problem by tracking which transid modified our extent, and then when we do
the tree logging we find all of the extents we've modified in our current
transaction, sort them and commit them. We also only truncate up to the
xattrs of the inode and copy that stuff in normally, and then just drop any
extents in the range we have that exist in the log already. Here are some
numbers of a 50 meg fio job that does random writes and fsync()s after every
write
Original Patched
SATA drive 82KB/s 140KB/s
Fusion drive 431KB/s 2532KB/s
So around 2-6 times faster depending on your hardware. There are a few
corner cases, for example if you truncate at all we have to do it the old
way since there is no way to be sure what is in the log is ok. This
probably could be done smarter, but if you write-fsync-truncate-write-fsync
you deserve what you get. All this work is in RAM of course so if your
inode gets evicted from cache and you read it in and fsync it we'll do it
the slow way if we are still in the same transaction that we last modified
the inode in.
The biggest cool part of this is that it requires no changes to the recovery
code, so if you fsync with this patch and crash and load an old kernel, it
will run the recovery and be a-ok. I have tested this pretty thoroughly
with an fsync tester and everything comes back fine, as well as xfstests.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 11:14:17 -06:00
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em->generation = 0;
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2007-08-27 14:49:44 -06:00
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atomic_set(&em->refs, 1);
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Btrfs: turbo charge fsync
At least for the vm workload. Currently on fsync we will
1) Truncate all items in the log tree for the given inode if they exist
and
2) Copy all items for a given inode into the log
The problem with this is that for things like VMs you can have lots of
extents from the fragmented writing behavior, and worst yet you may have
only modified a few extents, not the entire thing. This patch fixes this
problem by tracking which transid modified our extent, and then when we do
the tree logging we find all of the extents we've modified in our current
transaction, sort them and commit them. We also only truncate up to the
xattrs of the inode and copy that stuff in normally, and then just drop any
extents in the range we have that exist in the log already. Here are some
numbers of a 50 meg fio job that does random writes and fsync()s after every
write
Original Patched
SATA drive 82KB/s 140KB/s
Fusion drive 431KB/s 2532KB/s
So around 2-6 times faster depending on your hardware. There are a few
corner cases, for example if you truncate at all we have to do it the old
way since there is no way to be sure what is in the log is ok. This
probably could be done smarter, but if you write-fsync-truncate-write-fsync
you deserve what you get. All this work is in RAM of course so if your
inode gets evicted from cache and you read it in and fsync it we'll do it
the slow way if we are still in the same transaction that we last modified
the inode in.
The biggest cool part of this is that it requires no changes to the recovery
code, so if you fsync with this patch and crash and load an old kernel, it
will run the recovery and be a-ok. I have tested this pretty thoroughly
with an fsync tester and everything comes back fine, as well as xfstests.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 11:14:17 -06:00
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INIT_LIST_HEAD(&em->list);
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2007-08-27 14:49:44 -06:00
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return em;
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}
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2008-06-11 19:52:17 -06:00
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/**
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* free_extent_map - drop reference count of an extent_map
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2016-05-19 19:18:45 -06:00
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* @em: extent map being released
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2008-06-11 19:52:17 -06:00
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*
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* Drops the reference out on @em by one and free the structure
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* if the reference count hits zero.
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*/
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2007-08-27 14:49:44 -06:00
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void free_extent_map(struct extent_map *em)
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{
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2007-08-30 09:54:02 -06:00
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if (!em)
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return;
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2008-01-24 14:13:08 -07:00
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WARN_ON(atomic_read(&em->refs) == 0);
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2007-08-27 14:49:44 -06:00
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if (atomic_dec_and_test(&em->refs)) {
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2014-02-25 07:15:12 -07:00
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WARN_ON(extent_map_in_tree(em));
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Btrfs: turbo charge fsync
At least for the vm workload. Currently on fsync we will
1) Truncate all items in the log tree for the given inode if they exist
and
2) Copy all items for a given inode into the log
The problem with this is that for things like VMs you can have lots of
extents from the fragmented writing behavior, and worst yet you may have
only modified a few extents, not the entire thing. This patch fixes this
problem by tracking which transid modified our extent, and then when we do
the tree logging we find all of the extents we've modified in our current
transaction, sort them and commit them. We also only truncate up to the
xattrs of the inode and copy that stuff in normally, and then just drop any
extents in the range we have that exist in the log already. Here are some
numbers of a 50 meg fio job that does random writes and fsync()s after every
write
Original Patched
SATA drive 82KB/s 140KB/s
Fusion drive 431KB/s 2532KB/s
So around 2-6 times faster depending on your hardware. There are a few
corner cases, for example if you truncate at all we have to do it the old
way since there is no way to be sure what is in the log is ok. This
probably could be done smarter, but if you write-fsync-truncate-write-fsync
you deserve what you get. All this work is in RAM of course so if your
inode gets evicted from cache and you read it in and fsync it we'll do it
the slow way if we are still in the same transaction that we last modified
the inode in.
The biggest cool part of this is that it requires no changes to the recovery
code, so if you fsync with this patch and crash and load an old kernel, it
will run the recovery and be a-ok. I have tested this pretty thoroughly
with an fsync tester and everything comes back fine, as well as xfstests.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 11:14:17 -06:00
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WARN_ON(!list_empty(&em->list));
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2014-06-18 20:42:52 -06:00
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if (test_bit(EXTENT_FLAG_FS_MAPPING, &em->flags))
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2015-06-03 08:55:48 -06:00
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kfree(em->map_lookup);
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2007-08-27 14:49:44 -06:00
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kmem_cache_free(extent_map_cache, em);
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}
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}
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2013-11-24 20:23:51 -07:00
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/* simple helper to do math around the end of an extent, handling wrap */
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static u64 range_end(u64 start, u64 len)
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{
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if (start + len < start)
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return (u64)-1;
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return start + len;
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}
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static int tree_insert(struct rb_root *root, struct extent_map *em)
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2007-08-27 14:49:44 -06:00
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{
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2009-01-05 19:25:51 -07:00
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struct rb_node **p = &root->rb_node;
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struct rb_node *parent = NULL;
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2013-11-24 20:23:51 -07:00
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struct extent_map *entry = NULL;
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struct rb_node *orig_parent = NULL;
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u64 end = range_end(em->start, em->len);
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2007-08-27 14:49:44 -06:00
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2009-01-05 19:25:51 -07:00
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while (*p) {
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2007-08-27 14:49:44 -06:00
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parent = *p;
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2008-01-24 14:13:08 -07:00
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entry = rb_entry(parent, struct extent_map, rb_node);
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2013-11-24 20:23:51 -07:00
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if (em->start < entry->start)
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2007-08-27 14:49:44 -06:00
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p = &(*p)->rb_left;
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2013-11-24 20:23:51 -07:00
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else if (em->start >= extent_map_end(entry))
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2007-08-27 14:49:44 -06:00
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p = &(*p)->rb_right;
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else
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2013-11-24 20:23:51 -07:00
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return -EEXIST;
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2007-08-27 14:49:44 -06:00
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}
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2013-11-24 20:23:51 -07:00
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orig_parent = parent;
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while (parent && em->start >= extent_map_end(entry)) {
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parent = rb_next(parent);
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entry = rb_entry(parent, struct extent_map, rb_node);
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}
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if (parent)
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if (end > entry->start && em->start < extent_map_end(entry))
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return -EEXIST;
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parent = orig_parent;
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entry = rb_entry(parent, struct extent_map, rb_node);
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while (parent && em->start < entry->start) {
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parent = rb_prev(parent);
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entry = rb_entry(parent, struct extent_map, rb_node);
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}
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if (parent)
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if (end > entry->start && em->start < extent_map_end(entry))
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return -EEXIST;
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rb_link_node(&em->rb_node, orig_parent, p);
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rb_insert_color(&em->rb_node, root);
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return 0;
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2007-08-27 14:49:44 -06:00
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}
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2008-09-29 13:18:18 -06:00
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/*
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* search through the tree for an extent_map with a given offset. If
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* it can't be found, try to find some neighboring extents
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*/
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2007-08-27 14:49:44 -06:00
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static struct rb_node *__tree_search(struct rb_root *root, u64 offset,
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2008-01-22 14:47:59 -07:00
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struct rb_node **prev_ret,
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struct rb_node **next_ret)
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2007-08-27 14:49:44 -06:00
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{
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2009-01-05 19:25:51 -07:00
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struct rb_node *n = root->rb_node;
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2007-08-27 14:49:44 -06:00
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struct rb_node *prev = NULL;
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2008-01-22 14:47:59 -07:00
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struct rb_node *orig_prev = NULL;
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2008-01-24 14:13:08 -07:00
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struct extent_map *entry;
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struct extent_map *prev_entry = NULL;
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2007-08-27 14:49:44 -06:00
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2009-01-05 19:25:51 -07:00
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while (n) {
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2008-01-24 14:13:08 -07:00
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entry = rb_entry(n, struct extent_map, rb_node);
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2007-08-27 14:49:44 -06:00
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prev = n;
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prev_entry = entry;
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if (offset < entry->start)
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n = n->rb_left;
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2008-01-24 14:13:08 -07:00
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else if (offset >= extent_map_end(entry))
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2007-08-27 14:49:44 -06:00
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n = n->rb_right;
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else
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return n;
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}
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2008-01-22 14:47:59 -07:00
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if (prev_ret) {
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orig_prev = prev;
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2009-01-05 19:25:51 -07:00
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while (prev && offset >= extent_map_end(prev_entry)) {
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2008-01-22 14:47:59 -07:00
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prev = rb_next(prev);
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2008-01-24 14:13:08 -07:00
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prev_entry = rb_entry(prev, struct extent_map, rb_node);
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2008-01-22 14:47:59 -07:00
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}
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*prev_ret = prev;
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prev = orig_prev;
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}
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if (next_ret) {
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2008-01-24 14:13:08 -07:00
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prev_entry = rb_entry(prev, struct extent_map, rb_node);
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2009-01-05 19:25:51 -07:00
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while (prev && offset < prev_entry->start) {
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2008-01-22 14:47:59 -07:00
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prev = rb_prev(prev);
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2008-01-24 14:13:08 -07:00
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prev_entry = rb_entry(prev, struct extent_map, rb_node);
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2008-01-22 14:47:59 -07:00
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}
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*next_ret = prev;
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2007-08-27 14:49:44 -06:00
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}
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return NULL;
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}
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2008-09-29 13:18:18 -06:00
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/* check to see if two extent_map structs are adjacent and safe to merge */
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2008-01-24 14:13:08 -07:00
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static int mergable_maps(struct extent_map *prev, struct extent_map *next)
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2007-08-27 14:49:44 -06:00
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{
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2008-07-18 10:01:11 -06:00
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if (test_bit(EXTENT_FLAG_PINNED, &prev->flags))
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return 0;
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Btrfs: Add zlib compression support
This is a large change for adding compression on reading and writing,
both for inline and regular extents. It does some fairly large
surgery to the writeback paths.
Compression is off by default and enabled by mount -o compress. Even
when the -o compress mount option is not used, it is possible to read
compressed extents off the disk.
If compression for a given set of pages fails to make them smaller, the
file is flagged to avoid future compression attempts later.
* While finding delalloc extents, the pages are locked before being sent down
to the delalloc handler. This allows the delalloc handler to do complex things
such as cleaning the pages, marking them writeback and starting IO on their
behalf.
* Inline extents are inserted at delalloc time now. This allows us to compress
the data before inserting the inline extent, and it allows us to insert
an inline extent that spans multiple pages.
* All of the in-memory extent representations (extent_map.c, ordered-data.c etc)
are changed to record both an in-memory size and an on disk size, as well
as a flag for compression.
From a disk format point of view, the extent pointers in the file are changed
to record the on disk size of a given extent and some encoding flags.
Space in the disk format is allocated for compression encoding, as well
as encryption and a generic 'other' field. Neither the encryption or the
'other' field are currently used.
In order to limit the amount of data read for a single random read in the
file, the size of a compressed extent is limited to 128k. This is a
software only limit, the disk format supports u64 sized compressed extents.
In order to limit the ram consumed while processing extents, the uncompressed
size of a compressed extent is limited to 256k. This is a software only limit
and will be subject to tuning later.
Checksumming is still done on compressed extents, and it is done on the
uncompressed version of the data. This way additional encodings can be
layered on without having to figure out which encoding to checksum.
Compression happens at delalloc time, which is basically singled threaded because
it is usually done by a single pdflush thread. This makes it tricky to
spread the compression load across all the cpus on the box. We'll have to
look at parallel pdflush walks of dirty inodes at a later time.
Decompression is hooked into readpages and it does spread across CPUs nicely.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-10-29 12:49:59 -06:00
|
|
|
/*
|
|
|
|
* don't merge compressed extents, we need to know their
|
|
|
|
* actual size
|
|
|
|
*/
|
|
|
|
if (test_bit(EXTENT_FLAG_COMPRESSED, &prev->flags))
|
|
|
|
return 0;
|
|
|
|
|
2013-01-24 10:02:07 -07:00
|
|
|
if (test_bit(EXTENT_FLAG_LOGGING, &prev->flags) ||
|
|
|
|
test_bit(EXTENT_FLAG_LOGGING, &next->flags))
|
|
|
|
return 0;
|
|
|
|
|
2013-04-05 14:51:15 -06:00
|
|
|
/*
|
|
|
|
* We don't want to merge stuff that hasn't been written to the log yet
|
|
|
|
* since it may not reflect exactly what is on disk, and that would be
|
|
|
|
* bad.
|
|
|
|
*/
|
|
|
|
if (!list_empty(&prev->list) || !list_empty(&next->list))
|
|
|
|
return 0;
|
|
|
|
|
2008-01-24 14:13:08 -07:00
|
|
|
if (extent_map_end(prev) == next->start &&
|
|
|
|
prev->flags == next->flags &&
|
|
|
|
prev->bdev == next->bdev &&
|
|
|
|
((next->block_start == EXTENT_MAP_HOLE &&
|
|
|
|
prev->block_start == EXTENT_MAP_HOLE) ||
|
|
|
|
(next->block_start == EXTENT_MAP_INLINE &&
|
|
|
|
prev->block_start == EXTENT_MAP_INLINE) ||
|
|
|
|
(next->block_start == EXTENT_MAP_DELALLOC &&
|
|
|
|
prev->block_start == EXTENT_MAP_DELALLOC) ||
|
|
|
|
(next->block_start < EXTENT_MAP_LAST_BYTE - 1 &&
|
|
|
|
next->block_start == extent_map_block_end(prev)))) {
|
|
|
|
return 1;
|
|
|
|
}
|
2007-08-27 14:49:44 -06:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2011-07-13 21:18:33 -06:00
|
|
|
static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em)
|
2009-09-11 10:27:37 -06:00
|
|
|
{
|
|
|
|
struct extent_map *merge = NULL;
|
|
|
|
struct rb_node *rb;
|
|
|
|
|
|
|
|
if (em->start != 0) {
|
|
|
|
rb = rb_prev(&em->rb_node);
|
|
|
|
if (rb)
|
|
|
|
merge = rb_entry(rb, struct extent_map, rb_node);
|
|
|
|
if (rb && mergable_maps(merge, em)) {
|
|
|
|
em->start = merge->start;
|
2012-10-11 14:54:30 -06:00
|
|
|
em->orig_start = merge->orig_start;
|
2009-09-11 10:27:37 -06:00
|
|
|
em->len += merge->len;
|
|
|
|
em->block_len += merge->block_len;
|
|
|
|
em->block_start = merge->block_start;
|
2012-10-11 14:54:30 -06:00
|
|
|
em->mod_len = (em->mod_len + em->mod_start) - merge->mod_start;
|
|
|
|
em->mod_start = merge->mod_start;
|
|
|
|
em->generation = max(em->generation, merge->generation);
|
Btrfs: turbo charge fsync
At least for the vm workload. Currently on fsync we will
1) Truncate all items in the log tree for the given inode if they exist
and
2) Copy all items for a given inode into the log
The problem with this is that for things like VMs you can have lots of
extents from the fragmented writing behavior, and worst yet you may have
only modified a few extents, not the entire thing. This patch fixes this
problem by tracking which transid modified our extent, and then when we do
the tree logging we find all of the extents we've modified in our current
transaction, sort them and commit them. We also only truncate up to the
xattrs of the inode and copy that stuff in normally, and then just drop any
extents in the range we have that exist in the log already. Here are some
numbers of a 50 meg fio job that does random writes and fsync()s after every
write
Original Patched
SATA drive 82KB/s 140KB/s
Fusion drive 431KB/s 2532KB/s
So around 2-6 times faster depending on your hardware. There are a few
corner cases, for example if you truncate at all we have to do it the old
way since there is no way to be sure what is in the log is ok. This
probably could be done smarter, but if you write-fsync-truncate-write-fsync
you deserve what you get. All this work is in RAM of course so if your
inode gets evicted from cache and you read it in and fsync it we'll do it
the slow way if we are still in the same transaction that we last modified
the inode in.
The biggest cool part of this is that it requires no changes to the recovery
code, so if you fsync with this patch and crash and load an old kernel, it
will run the recovery and be a-ok. I have tested this pretty thoroughly
with an fsync tester and everything comes back fine, as well as xfstests.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 11:14:17 -06:00
|
|
|
|
2009-09-11 10:27:37 -06:00
|
|
|
rb_erase(&merge->rb_node, &tree->map);
|
2014-02-25 07:15:12 -07:00
|
|
|
RB_CLEAR_NODE(&merge->rb_node);
|
2009-09-11 10:27:37 -06:00
|
|
|
free_extent_map(merge);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
rb = rb_next(&em->rb_node);
|
|
|
|
if (rb)
|
|
|
|
merge = rb_entry(rb, struct extent_map, rb_node);
|
|
|
|
if (rb && mergable_maps(em, merge)) {
|
|
|
|
em->len += merge->len;
|
2013-11-30 04:28:35 -07:00
|
|
|
em->block_len += merge->block_len;
|
2009-09-11 10:27:37 -06:00
|
|
|
rb_erase(&merge->rb_node, &tree->map);
|
2014-02-25 07:15:12 -07:00
|
|
|
RB_CLEAR_NODE(&merge->rb_node);
|
2012-10-11 14:54:30 -06:00
|
|
|
em->mod_len = (merge->mod_start + merge->mod_len) - em->mod_start;
|
|
|
|
em->generation = max(em->generation, merge->generation);
|
2009-09-11 10:27:37 -06:00
|
|
|
free_extent_map(merge);
|
|
|
|
}
|
2011-07-13 21:18:33 -06:00
|
|
|
}
|
|
|
|
|
Btrfs: turbo charge fsync
At least for the vm workload. Currently on fsync we will
1) Truncate all items in the log tree for the given inode if they exist
and
2) Copy all items for a given inode into the log
The problem with this is that for things like VMs you can have lots of
extents from the fragmented writing behavior, and worst yet you may have
only modified a few extents, not the entire thing. This patch fixes this
problem by tracking which transid modified our extent, and then when we do
the tree logging we find all of the extents we've modified in our current
transaction, sort them and commit them. We also only truncate up to the
xattrs of the inode and copy that stuff in normally, and then just drop any
extents in the range we have that exist in the log already. Here are some
numbers of a 50 meg fio job that does random writes and fsync()s after every
write
Original Patched
SATA drive 82KB/s 140KB/s
Fusion drive 431KB/s 2532KB/s
So around 2-6 times faster depending on your hardware. There are a few
corner cases, for example if you truncate at all we have to do it the old
way since there is no way to be sure what is in the log is ok. This
probably could be done smarter, but if you write-fsync-truncate-write-fsync
you deserve what you get. All this work is in RAM of course so if your
inode gets evicted from cache and you read it in and fsync it we'll do it
the slow way if we are still in the same transaction that we last modified
the inode in.
The biggest cool part of this is that it requires no changes to the recovery
code, so if you fsync with this patch and crash and load an old kernel, it
will run the recovery and be a-ok. I have tested this pretty thoroughly
with an fsync tester and everything comes back fine, as well as xfstests.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 11:14:17 -06:00
|
|
|
/**
|
2012-10-30 03:13:52 -06:00
|
|
|
* unpin_extent_cache - unpin an extent from the cache
|
Btrfs: turbo charge fsync
At least for the vm workload. Currently on fsync we will
1) Truncate all items in the log tree for the given inode if they exist
and
2) Copy all items for a given inode into the log
The problem with this is that for things like VMs you can have lots of
extents from the fragmented writing behavior, and worst yet you may have
only modified a few extents, not the entire thing. This patch fixes this
problem by tracking which transid modified our extent, and then when we do
the tree logging we find all of the extents we've modified in our current
transaction, sort them and commit them. We also only truncate up to the
xattrs of the inode and copy that stuff in normally, and then just drop any
extents in the range we have that exist in the log already. Here are some
numbers of a 50 meg fio job that does random writes and fsync()s after every
write
Original Patched
SATA drive 82KB/s 140KB/s
Fusion drive 431KB/s 2532KB/s
So around 2-6 times faster depending on your hardware. There are a few
corner cases, for example if you truncate at all we have to do it the old
way since there is no way to be sure what is in the log is ok. This
probably could be done smarter, but if you write-fsync-truncate-write-fsync
you deserve what you get. All this work is in RAM of course so if your
inode gets evicted from cache and you read it in and fsync it we'll do it
the slow way if we are still in the same transaction that we last modified
the inode in.
The biggest cool part of this is that it requires no changes to the recovery
code, so if you fsync with this patch and crash and load an old kernel, it
will run the recovery and be a-ok. I have tested this pretty thoroughly
with an fsync tester and everything comes back fine, as well as xfstests.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 11:14:17 -06:00
|
|
|
* @tree: tree to unpin the extent in
|
|
|
|
* @start: logical offset in the file
|
|
|
|
* @len: length of the extent
|
|
|
|
* @gen: generation that this extent has been modified in
|
|
|
|
*
|
|
|
|
* Called after an extent has been written to disk properly. Set the generation
|
|
|
|
* to the generation that actually added the file item to the inode so we know
|
|
|
|
* we need to sync this extent when we call fsync().
|
|
|
|
*/
|
|
|
|
int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len,
|
|
|
|
u64 gen)
|
2011-07-13 21:18:33 -06:00
|
|
|
{
|
|
|
|
int ret = 0;
|
|
|
|
struct extent_map *em;
|
2012-08-27 10:52:20 -06:00
|
|
|
bool prealloc = false;
|
2011-07-13 21:18:33 -06:00
|
|
|
|
|
|
|
write_lock(&tree->lock);
|
|
|
|
em = lookup_extent_mapping(tree, start, len);
|
|
|
|
|
|
|
|
WARN_ON(!em || em->start != start);
|
|
|
|
|
|
|
|
if (!em)
|
|
|
|
goto out;
|
|
|
|
|
Btrfs: turbo charge fsync
At least for the vm workload. Currently on fsync we will
1) Truncate all items in the log tree for the given inode if they exist
and
2) Copy all items for a given inode into the log
The problem with this is that for things like VMs you can have lots of
extents from the fragmented writing behavior, and worst yet you may have
only modified a few extents, not the entire thing. This patch fixes this
problem by tracking which transid modified our extent, and then when we do
the tree logging we find all of the extents we've modified in our current
transaction, sort them and commit them. We also only truncate up to the
xattrs of the inode and copy that stuff in normally, and then just drop any
extents in the range we have that exist in the log already. Here are some
numbers of a 50 meg fio job that does random writes and fsync()s after every
write
Original Patched
SATA drive 82KB/s 140KB/s
Fusion drive 431KB/s 2532KB/s
So around 2-6 times faster depending on your hardware. There are a few
corner cases, for example if you truncate at all we have to do it the old
way since there is no way to be sure what is in the log is ok. This
probably could be done smarter, but if you write-fsync-truncate-write-fsync
you deserve what you get. All this work is in RAM of course so if your
inode gets evicted from cache and you read it in and fsync it we'll do it
the slow way if we are still in the same transaction that we last modified
the inode in.
The biggest cool part of this is that it requires no changes to the recovery
code, so if you fsync with this patch and crash and load an old kernel, it
will run the recovery and be a-ok. I have tested this pretty thoroughly
with an fsync tester and everything comes back fine, as well as xfstests.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 11:14:17 -06:00
|
|
|
em->generation = gen;
|
2011-07-13 21:18:33 -06:00
|
|
|
clear_bit(EXTENT_FLAG_PINNED, &em->flags);
|
2012-08-27 10:52:20 -06:00
|
|
|
em->mod_start = em->start;
|
|
|
|
em->mod_len = em->len;
|
|
|
|
|
2012-12-03 08:58:15 -07:00
|
|
|
if (test_bit(EXTENT_FLAG_FILLING, &em->flags)) {
|
2012-08-27 10:52:20 -06:00
|
|
|
prealloc = true;
|
2012-12-03 08:58:15 -07:00
|
|
|
clear_bit(EXTENT_FLAG_FILLING, &em->flags);
|
2012-08-27 10:52:20 -06:00
|
|
|
}
|
2011-07-13 21:18:33 -06:00
|
|
|
|
|
|
|
try_merge_map(tree, em);
|
2012-08-27 10:52:20 -06:00
|
|
|
|
|
|
|
if (prealloc) {
|
|
|
|
em->mod_start = em->start;
|
|
|
|
em->mod_len = em->len;
|
|
|
|
}
|
|
|
|
|
2009-09-11 10:27:37 -06:00
|
|
|
free_extent_map(em);
|
|
|
|
out:
|
|
|
|
write_unlock(&tree->lock);
|
|
|
|
return ret;
|
|
|
|
|
|
|
|
}
|
|
|
|
|
2013-01-24 10:02:07 -07:00
|
|
|
void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em)
|
|
|
|
{
|
|
|
|
clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
|
2014-02-25 07:15:12 -07:00
|
|
|
if (extent_map_in_tree(em))
|
2013-01-28 07:45:20 -07:00
|
|
|
try_merge_map(tree, em);
|
2013-01-24 10:02:07 -07:00
|
|
|
}
|
|
|
|
|
2014-02-25 07:15:13 -07:00
|
|
|
static inline void setup_extent_mapping(struct extent_map_tree *tree,
|
|
|
|
struct extent_map *em,
|
|
|
|
int modified)
|
|
|
|
{
|
|
|
|
atomic_inc(&em->refs);
|
|
|
|
em->mod_start = em->start;
|
|
|
|
em->mod_len = em->len;
|
|
|
|
|
|
|
|
if (modified)
|
|
|
|
list_move(&em->list, &tree->modified_extents);
|
|
|
|
else
|
|
|
|
try_merge_map(tree, em);
|
|
|
|
}
|
|
|
|
|
2008-06-11 19:52:17 -06:00
|
|
|
/**
|
|
|
|
* add_extent_mapping - add new extent map to the extent tree
|
|
|
|
* @tree: tree to insert new map in
|
|
|
|
* @em: map to insert
|
|
|
|
*
|
|
|
|
* Insert @em into @tree or perform a simple forward/backward merge with
|
|
|
|
* existing mappings. The extent_map struct passed in will be inserted
|
|
|
|
* into the tree directly, with an additional reference taken, or a
|
2011-03-30 19:57:33 -06:00
|
|
|
* reference dropped if the merge attempt was successful.
|
2007-08-27 14:49:44 -06:00
|
|
|
*/
|
|
|
|
int add_extent_mapping(struct extent_map_tree *tree,
|
2013-04-05 14:51:15 -06:00
|
|
|
struct extent_map *em, int modified)
|
2007-08-27 14:49:44 -06:00
|
|
|
{
|
|
|
|
int ret = 0;
|
|
|
|
|
2013-11-24 20:23:51 -07:00
|
|
|
ret = tree_insert(&tree->map, em);
|
|
|
|
if (ret)
|
2007-08-27 14:49:44 -06:00
|
|
|
goto out;
|
2013-11-24 20:23:51 -07:00
|
|
|
|
2014-02-25 07:15:13 -07:00
|
|
|
setup_extent_mapping(tree, em, modified);
|
2007-08-27 14:49:44 -06:00
|
|
|
out:
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
2013-04-25 14:41:01 -06:00
|
|
|
static struct extent_map *
|
|
|
|
__lookup_extent_mapping(struct extent_map_tree *tree,
|
|
|
|
u64 start, u64 len, int strict)
|
2007-08-27 14:49:44 -06:00
|
|
|
{
|
|
|
|
struct extent_map *em;
|
|
|
|
struct rb_node *rb_node;
|
2008-06-10 08:21:04 -06:00
|
|
|
struct rb_node *prev = NULL;
|
|
|
|
struct rb_node *next = NULL;
|
|
|
|
u64 end = range_end(start, len);
|
|
|
|
|
2008-01-22 14:47:59 -07:00
|
|
|
rb_node = __tree_search(&tree->map, start, &prev, &next);
|
2007-08-27 14:49:44 -06:00
|
|
|
if (!rb_node) {
|
2011-07-13 21:18:15 -06:00
|
|
|
if (prev)
|
|
|
|
rb_node = prev;
|
|
|
|
else if (next)
|
|
|
|
rb_node = next;
|
|
|
|
else
|
|
|
|
return NULL;
|
2007-08-27 14:49:44 -06:00
|
|
|
}
|
2011-07-13 21:18:15 -06:00
|
|
|
|
2007-08-27 14:49:44 -06:00
|
|
|
em = rb_entry(rb_node, struct extent_map, rb_node);
|
2008-01-24 14:13:08 -07:00
|
|
|
|
2011-07-13 21:18:15 -06:00
|
|
|
if (strict && !(end > em->start && start < extent_map_end(em)))
|
|
|
|
return NULL;
|
2008-01-24 14:13:08 -07:00
|
|
|
|
2007-08-27 14:49:44 -06:00
|
|
|
atomic_inc(&em->refs);
|
|
|
|
return em;
|
|
|
|
}
|
|
|
|
|
2011-07-13 21:18:15 -06:00
|
|
|
/**
|
|
|
|
* lookup_extent_mapping - lookup extent_map
|
|
|
|
* @tree: tree to lookup in
|
|
|
|
* @start: byte offset to start the search
|
|
|
|
* @len: length of the lookup range
|
|
|
|
*
|
|
|
|
* Find and return the first extent_map struct in @tree that intersects the
|
|
|
|
* [start, len] range. There may be additional objects in the tree that
|
|
|
|
* intersect, so check the object returned carefully to make sure that no
|
|
|
|
* additional lookups are needed.
|
|
|
|
*/
|
|
|
|
struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
|
|
|
|
u64 start, u64 len)
|
|
|
|
{
|
|
|
|
return __lookup_extent_mapping(tree, start, len, 1);
|
|
|
|
}
|
|
|
|
|
2009-09-18 14:07:03 -06:00
|
|
|
/**
|
|
|
|
* search_extent_mapping - find a nearby extent map
|
|
|
|
* @tree: tree to lookup in
|
|
|
|
* @start: byte offset to start the search
|
|
|
|
* @len: length of the lookup range
|
|
|
|
*
|
|
|
|
* Find and return the first extent_map struct in @tree that intersects the
|
|
|
|
* [start, len] range.
|
|
|
|
*
|
|
|
|
* If one can't be found, any nearby extent may be returned
|
|
|
|
*/
|
|
|
|
struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
|
|
|
|
u64 start, u64 len)
|
|
|
|
{
|
2011-07-13 21:18:15 -06:00
|
|
|
return __lookup_extent_mapping(tree, start, len, 0);
|
2009-09-18 14:07:03 -06:00
|
|
|
}
|
|
|
|
|
2008-06-11 19:52:17 -06:00
|
|
|
/**
|
|
|
|
* remove_extent_mapping - removes an extent_map from the extent tree
|
|
|
|
* @tree: extent tree to remove from
|
2016-03-04 12:23:12 -07:00
|
|
|
* @em: extent map being removed
|
2008-06-11 19:52:17 -06:00
|
|
|
*
|
|
|
|
* Removes @em from @tree. No reference counts are dropped, and no checks
|
|
|
|
* are done to see if the range is in use
|
2007-08-27 14:49:44 -06:00
|
|
|
*/
|
|
|
|
int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em)
|
|
|
|
{
|
2008-01-24 14:13:08 -07:00
|
|
|
int ret = 0;
|
2007-08-27 14:49:44 -06:00
|
|
|
|
2008-07-18 10:01:11 -06:00
|
|
|
WARN_ON(test_bit(EXTENT_FLAG_PINNED, &em->flags));
|
2008-01-24 14:13:08 -07:00
|
|
|
rb_erase(&em->rb_node, &tree->map);
|
2012-09-14 10:59:20 -06:00
|
|
|
if (!test_bit(EXTENT_FLAG_LOGGING, &em->flags))
|
|
|
|
list_del_init(&em->list);
|
2014-02-25 07:15:12 -07:00
|
|
|
RB_CLEAR_NODE(&em->rb_node);
|
2007-08-27 14:49:44 -06:00
|
|
|
return ret;
|
|
|
|
}
|
2014-02-25 07:15:13 -07:00
|
|
|
|
|
|
|
void replace_extent_mapping(struct extent_map_tree *tree,
|
|
|
|
struct extent_map *cur,
|
|
|
|
struct extent_map *new,
|
|
|
|
int modified)
|
|
|
|
{
|
|
|
|
WARN_ON(test_bit(EXTENT_FLAG_PINNED, &cur->flags));
|
|
|
|
ASSERT(extent_map_in_tree(cur));
|
|
|
|
if (!test_bit(EXTENT_FLAG_LOGGING, &cur->flags))
|
|
|
|
list_del_init(&cur->list);
|
|
|
|
rb_replace_node(&cur->rb_node, &new->rb_node, &tree->map);
|
|
|
|
RB_CLEAR_NODE(&cur->rb_node);
|
|
|
|
|
|
|
|
setup_extent_mapping(tree, new, modified);
|
|
|
|
}
|