The patch titled
reiser4: improve estimation for number of nodes occupied by disk cluster
has been added to the -mm tree. Its filename is
reiser4-improve-estimation-for-number-of-nodes-occupied.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: reiser4: improve estimation for number of nodes occupied by disk cluster
From: Edward Shishkin <edward@xxxxxxxxxxx>
Improved estimation for amount of dirty nodes occupied by a disk cluster (old
estimation means 256M of dead space on a partition).
Signed-off-by: Edward Shishkin <edward@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/reiser4/estimate.c | 15 +++++++++++----
fs/reiser4/plugin/cluster.h | 16 ++++++++++++++++
fs/reiser4/plugin/file/cryptcompress.c | 20 +++++++++++++++++++-
fs/reiser4/plugin/item/ctail.h | 23 ++++++++++++++---------
4 files changed, 60 insertions(+), 14 deletions(-)
diff -puN fs/reiser4/estimate.c~reiser4-improve-estimation-for-number-of-nodes-occupied fs/reiser4/estimate.c
--- a/fs/reiser4/estimate.c~reiser4-improve-estimation-for-number-of-nodes-occupied
+++ a/fs/reiser4/estimate.c
@@ -93,12 +93,19 @@ reiser4_block_nr estimate_update_cluster
return estimate_cluster(inode, 0); /* 44, for 64K-cluster */
}
-/* how many nodes occupied by a disk cluster might get dirty
- FIXME-EDWARD: This estimation is pretty bad (65536 nodes for
- 64K-cluster, it means 256M of dead space on the partition) */
+/* How many nodes occupied by a disk cluster might get dirty.
+ Note that this estimation is not precise (i.e. disk cluster
+ can occupy more nodes).
+ Q: Why we don't use precise estimation?
+ A: 1.Because precise estimation is fairly bad: 65536 nodes
+ for 64K logical cluster, it means 256M of dead space on
+ a partition
+ 2.It is a very rare case when disk cluster occupies more
+ nodes then this estimation returns.
+*/
reiser4_block_nr estimate_dirty_cluster(struct inode * inode)
{
- return inode_cluster_size(inode);
+ return cluster_nrpages(inode) + 4;
}
/* Make Linus happy.
diff -puN fs/reiser4/plugin/cluster.h~reiser4-improve-estimation-for-number-of-nodes-occupied fs/reiser4/plugin/cluster.h
--- a/fs/reiser4/plugin/cluster.h~reiser4-improve-estimation-for-number-of-nodes-occupied
+++ a/fs/reiser4/plugin/cluster.h
@@ -226,6 +226,22 @@ static inline int dclust_get_extension_s
return hint->ext_coord.extension.ctail.shift;
}
+static inline int dclust_get_extension_ncount(hint_t * hint)
+{
+ return hint->ext_coord.extension.ctail.ncount;
+}
+
+static inline void dclust_inc_extension_ncount(hint_t * hint)
+{
+ hint->ext_coord.extension.ctail.ncount ++;
+}
+
+static inline void dclust_init_extension(hint_t * hint)
+{
+ memset(&hint->ext_coord.extension.ctail, 0,
+ sizeof(hint->ext_coord.extension.ctail));
+}
+
static inline int hint_is_unprepped_dclust(hint_t * hint)
{
assert("edward-1451", hint_is_valid(hint));
diff -puN fs/reiser4/plugin/file/cryptcompress.c~reiser4-improve-estimation-for-number-of-nodes-occupied fs/reiser4/plugin/file/cryptcompress.c
--- a/fs/reiser4/plugin/file/cryptcompress.c~reiser4-improve-estimation-for-number-of-nodes-occupied
+++ a/fs/reiser4/plugin/file/cryptcompress.c
@@ -742,6 +742,7 @@ static int find_cluster_item(hint_t * hi
{
int result;
reiser4_key ikey;
+ int went_right = 0;
coord_t *coord = &hint->ext_coord.coord;
coord_t orig = *coord;
@@ -771,6 +772,7 @@ static int find_cluster_item(hint_t * hi
if (result)
return result;
assert("edward-1218", equal_to_ldk(coord->node, key));
+ went_right = 1;
} else {
coord->item_pos++;
coord->unit_pos = 0;
@@ -789,6 +791,9 @@ static int find_cluster_item(hint_t * hi
zrelse(coord->node);
if (!keyeq(key, &ikey))
goto not_found;
+ /* Ok, item is found, update node counts */
+ if (went_right)
+ dclust_inc_extension_ncount(hint);
return CBK_COORD_FOUND;
not_found:
@@ -804,12 +809,15 @@ static int find_cluster_item(hint_t * hi
assert("edward-714", reiser4_schedulable());
reiser4_unset_hint(hint);
+ dclust_init_extension(hint);
coord_init_zero(coord);
result = coord_by_key(current_tree, key, coord, &hint->lh,
lock_mode, bias, LEAF_LEVEL, LEAF_LEVEL,
CBK_UNIQUE | flags, ra_info);
if (cbk_errored(result))
return result;
+ if(result == CBK_COORD_FOUND)
+ dclust_inc_extension_ncount(hint);
hint_set_valid(hint);
return result;
}
@@ -2017,6 +2025,8 @@ int find_disk_cluster(reiser4_cluster_t
assert("edward-462", !tfm_cluster_is_uptodate(tc));
assert("edward-461", ergo(read, tfm_stream_is_set(tc, INPUT_STREAM)));
+ dclust_init_extension(hint);
+
/* set key of the first disk cluster item */
fplug->flow_by_inode(inode,
(read ? (char __user *)tfm_stream_data(tc, INPUT_STREAM) : NULL),
@@ -2078,7 +2088,15 @@ int find_disk_cluster(reiser4_cluster_t
goto out;
}
if (mode == ZNODE_WRITE_LOCK) {
- znode_make_dirty(hint->ext_coord.coord.node);
+ /* Don't make dirty more nodes then it was
+ estimated (see comments before
+ estimate_dirty_cluster). Missed nodes will be
+ read up in flush time if they are evicted from
+ memory */
+ if (dclust_get_extension_ncount(hint) <=
+ estimate_dirty_cluster(inode))
+ znode_make_dirty(hint->ext_coord.coord.node);
+
znode_set_convertible(hint->ext_coord.coord.
node);
}
diff -puN fs/reiser4/plugin/item/ctail.h~reiser4-improve-estimation-for-number-of-nodes-occupied fs/reiser4/plugin/item/ctail.h
--- a/fs/reiser4/plugin/item/ctail.h~reiser4-improve-estimation-for-number-of-nodes-occupied
+++ a/fs/reiser4/plugin/item/ctail.h
@@ -3,20 +3,22 @@
#if !defined( __FS_REISER4_CTAIL_H__ )
#define __FS_REISER4_CTAIL_H__
-/* cryptcompress object item. See ctail.c for description. */
-
-/* number of units and cluster_shift of ctail item
- that represents unprepped disk cluster */
-#define UCTAIL_NR_UNITS 1
-#define UCTAIL_SHIFT 0xff
-
+/* Disk format of ctail item */
typedef struct ctail_item_format {
- /* cluster shift */
+ /* packed shift; size of (prepped) disk cluster
+ is calculated as (1 << cluster_shift) */
d8 cluster_shift;
/* ctail body */
d8 body[0];
} __attribute__ ((packed)) ctail_item_format;
+/* Unprepped disk cluster is represented by a single ctail item
+ with the following "magic" attributes: */
+/* "magic" cluster_shift */
+#define UCTAIL_SHIFT 0xff
+/* How many units unprepped ctail item has */
+#define UCTAIL_NR_UNITS 1
+
/* The following is a set of various item states in a disk cluster.
Disk cluster is a set of items whose keys belong to the interval
[dc_key , dc_key + disk_cluster_size - 1] */
@@ -27,11 +29,14 @@ typedef enum {
DC_AFTER_CLUSTER = 3
} dc_item_stat;
+/* ctail-specific extension.
+ In particular this describes parameters of disk cluster an item belongs to */
typedef struct {
int shift; /* this contains cluster_shift extracted from
ctail_item_format (above), or UCTAIL_SHIFT
- (the last one is for unprepped disk clusters) */
+ (the last one is the "magic" of unprepped disk clusters)*/
int dsize; /* size of a prepped disk cluster */
+ int ncount; /* count of nodes occupied by a disk cluster */
} ctail_coord_extension_t;
struct cut_list;
_
Patches currently in -mm which might be from edward@xxxxxxxxxxx are
reiser4-vs-streamline-generic_file_-interfaces-and-filemap-fix.patch
reiser4-rename-generic_sounding_globalspatch.patch
reiser4-use-generic-file-read-fix-readpages-unix-file.patch
reiser4-format-subversion-numbers-heir-set-and-file-conversion.patch
reiser4-format-subversion-numbers-heir-set-and-file-conversion-fix-readpages-cryptcompress.patch
reiser4-cleanups-in-lzo-compression-library.patch
reiser4-get-rid-of-deprecated-crypto-api.patch
reiser4-get-rid-of-deprecated-crypto-api-build-fix.patch
reiser4-fix-missed-unlock-and-exit_context.patch
reiser4-use-list_head-instead-of-struct-blocknr.patch
reiser4-use-list_empty-instead-of-list_empty_careful-for.patch
reiser4-update-comments-fix-write-and-truncate-cryptcompress.patch
reiser4-temp-fix.patch
reiser4-fix-write_extent-1.patch
fs-reiser4-possible-cleanups-2.patch
fs-reiser4-more-possible-cleanups.patch
reiser4-use-null-for-pointers.patch
reiser4-test_clear_page_dirty.patch
reiser4-fix-readpage_cryptcompress.patch
reiser4-improve-estimation-for-number-of-nodes-occupied.patch
reiser4-drop-check_cryptcompress.patch
reiser4-vs-git-block.patch
reiser4-vs-git-block-2.patch
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