aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorChris Mason <chris.mason@oracle.com>2009-09-02 16:24:52 -0400
committerChris Mason <chris.mason@oracle.com>2009-09-11 13:31:05 -0400
commit890871be854b5f5e43e7ba2475f706209906cc24 (patch)
tree9d087adf7a28bb910992d07d93ea2a992e394110
parent57fd5a5ff8b48b99e90b22fc143082aba755c6c0 (diff)
Btrfs: switch extent_map to a rw lock
There are two main users of the extent_map tree. The first is regular file inodes, where it is evenly spread between readers and writers. The second is the chunk allocation tree, which maps blocks from logical addresses to phyiscal ones, and it is 99.99% reads. The mapping tree is a point of lock contention during heavy IO workloads, so this commit switches things to a rw lock. Signed-off-by: Chris Mason <chris.mason@oracle.com>
-rw-r--r--fs/btrfs/compression.c8
-rw-r--r--fs/btrfs/disk-io.c14
-rw-r--r--fs/btrfs/extent-tree.c4
-rw-r--r--fs/btrfs/extent_io.c8
-rw-r--r--fs/btrfs/extent_map.c5
-rw-r--r--fs/btrfs/extent_map.h2
-rw-r--r--fs/btrfs/file.c8
-rw-r--r--fs/btrfs/inode.c24
-rw-r--r--fs/btrfs/relocation.c4
-rw-r--r--fs/btrfs/volumes.c40
10 files changed, 57 insertions, 60 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index de1e2fd3208..78451a58f20 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -507,10 +507,10 @@ static noinline int add_ra_bio_pages(struct inode *inode,
*/
set_page_extent_mapped(page);
lock_extent(tree, last_offset, end, GFP_NOFS);
- spin_lock(&em_tree->lock);
+ read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, last_offset,
PAGE_CACHE_SIZE);
- spin_unlock(&em_tree->lock);
+ read_unlock(&em_tree->lock);
if (!em || last_offset < em->start ||
(last_offset + PAGE_CACHE_SIZE > extent_map_end(em)) ||
@@ -594,11 +594,11 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
em_tree = &BTRFS_I(inode)->extent_tree;
/* we need the actual starting offset of this extent in the file */
- spin_lock(&em_tree->lock);
+ read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree,
page_offset(bio->bi_io_vec->bv_page),
PAGE_CACHE_SIZE);
- spin_unlock(&em_tree->lock);
+ read_unlock(&em_tree->lock);
compressed_len = em->block_len;
cb = kmalloc(compressed_bio_size(root, compressed_len), GFP_NOFS);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 20cefc6f22c..b6cfdd9164e 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -121,15 +121,15 @@ static struct extent_map *btree_get_extent(struct inode *inode,
struct extent_map *em;
int ret;
- spin_lock(&em_tree->lock);
+ read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, len);
if (em) {
em->bdev =
BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
- spin_unlock(&em_tree->lock);
+ read_unlock(&em_tree->lock);
goto out;
}
- spin_unlock(&em_tree->lock);
+ read_unlock(&em_tree->lock);
em = alloc_extent_map(GFP_NOFS);
if (!em) {
@@ -142,7 +142,7 @@ static struct extent_map *btree_get_extent(struct inode *inode,
em->block_start = 0;
em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
- spin_lock(&em_tree->lock);
+ write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
if (ret == -EEXIST) {
u64 failed_start = em->start;
@@ -161,7 +161,7 @@ static struct extent_map *btree_get_extent(struct inode *inode,
free_extent_map(em);
em = NULL;
}
- spin_unlock(&em_tree->lock);
+ write_unlock(&em_tree->lock);
if (ret)
em = ERR_PTR(ret);
@@ -1323,9 +1323,9 @@ static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
offset = page_offset(page);
em_tree = &BTRFS_I(inode)->extent_tree;
- spin_lock(&em_tree->lock);
+ read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
- spin_unlock(&em_tree->lock);
+ read_unlock(&em_tree->lock);
if (!em) {
__unplug_io_fn(bdi, page);
return;
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 72a2b9c28e9..edd86ae9e14 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5396,9 +5396,9 @@ static noinline int relocate_data_extent(struct inode *reloc_inode,
lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
while (1) {
int ret;
- spin_lock(&em_tree->lock);
+ write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
- spin_unlock(&em_tree->lock);
+ write_unlock(&em_tree->lock);
if (ret != -EEXIST) {
free_extent_map(em);
break;
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 8d7a152a90c..41cf1b451b4 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2786,15 +2786,15 @@ int try_release_extent_mapping(struct extent_map_tree *map,
u64 len;
while (start <= end) {
len = end - start + 1;
- spin_lock(&map->lock);
+ write_lock(&map->lock);
em = lookup_extent_mapping(map, start, len);
if (!em || IS_ERR(em)) {
- spin_unlock(&map->lock);
+ write_unlock(&map->lock);
break;
}
if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
em->start != start) {
- spin_unlock(&map->lock);
+ write_unlock(&map->lock);
free_extent_map(em);
break;
}
@@ -2808,7 +2808,7 @@ int try_release_extent_mapping(struct extent_map_tree *map,
free_extent_map(em);
}
start = extent_map_end(em);
- spin_unlock(&map->lock);
+ write_unlock(&map->lock);
/* once for us */
free_extent_map(em);
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 30c9365861e..72e9fa3c31f 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -36,7 +36,7 @@ void extent_map_exit(void)
void extent_map_tree_init(struct extent_map_tree *tree, gfp_t mask)
{
tree->map.rb_node = NULL;
- spin_lock_init(&tree->lock);
+ rwlock_init(&tree->lock);
}
/**
@@ -222,7 +222,6 @@ int add_extent_mapping(struct extent_map_tree *tree,
ret = -EEXIST;
goto out;
}
- assert_spin_locked(&tree->lock);
rb = tree_insert(&tree->map, em->start, &em->rb_node);
if (rb) {
ret = -EEXIST;
@@ -285,7 +284,6 @@ struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
struct rb_node *next = NULL;
u64 end = range_end(start, len);
- assert_spin_locked(&tree->lock);
rb_node = __tree_search(&tree->map, start, &prev, &next);
if (!rb_node && prev) {
em = rb_entry(prev, struct extent_map, rb_node);
@@ -331,7 +329,6 @@ int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em)
int ret = 0;
WARN_ON(test_bit(EXTENT_FLAG_PINNED, &em->flags));
- assert_spin_locked(&tree->lock);
rb_erase(&em->rb_node, &tree->map);
em->in_tree = 0;
return ret;
diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
index fb6eeef06bb..6216dfbcf9b 100644
--- a/fs/btrfs/extent_map.h
+++ b/fs/btrfs/extent_map.h
@@ -31,7 +31,7 @@ struct extent_map {
struct extent_map_tree {
struct rb_root map;
- spinlock_t lock;
+ rwlock_t lock;
};
static inline u64 extent_map_end(struct extent_map *em)
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index a760d97279a..8a9c76aecdf 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -188,15 +188,15 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
if (!split2)
split2 = alloc_extent_map(GFP_NOFS);
- spin_lock(&em_tree->lock);
+ write_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, len);
if (!em) {
- spin_unlock(&em_tree->lock);
+ write_unlock(&em_tree->lock);
break;
}
flags = em->flags;
if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
- spin_unlock(&em_tree->lock);
+ write_unlock(&em_tree->lock);
if (em->start <= start &&
(!testend || em->start + em->len >= start + len)) {
free_extent_map(em);
@@ -259,7 +259,7 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
free_extent_map(split);
split = NULL;
}
- spin_unlock(&em_tree->lock);
+ write_unlock(&em_tree->lock);
/* once for us */
free_extent_map(em);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 04b53b5ebe5..f1df1171861 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -612,9 +612,9 @@ static noinline int submit_compressed_extents(struct inode *inode,
set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
while (1) {
- spin_lock(&em_tree->lock);
+ write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
- spin_unlock(&em_tree->lock);
+ write_unlock(&em_tree->lock);
if (ret != -EEXIST) {
free_extent_map(em);
break;
@@ -748,9 +748,9 @@ static noinline int cow_file_range(struct inode *inode,
set_bit(EXTENT_FLAG_PINNED, &em->flags);
while (1) {
- spin_lock(&em_tree->lock);
+ write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
- spin_unlock(&em_tree->lock);
+ write_unlock(&em_tree->lock);
if (ret != -EEXIST) {
free_extent_map(em);
break;
@@ -1081,9 +1081,9 @@ out_check:
em->bdev = root->fs_info->fs_devices->latest_bdev;
set_bit(EXTENT_FLAG_PINNED, &em->flags);
while (1) {
- spin_lock(&em_tree->lock);
+ write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
- spin_unlock(&em_tree->lock);
+ write_unlock(&em_tree->lock);
if (ret != -EEXIST) {
free_extent_map(em);
break;
@@ -1670,13 +1670,13 @@ static int btrfs_io_failed_hook(struct bio *failed_bio,
failrec->last_mirror = 0;
failrec->bio_flags = 0;
- spin_lock(&em_tree->lock);
+ read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, failrec->len);
if (em->start > start || em->start + em->len < start) {
free_extent_map(em);
em = NULL;
}
- spin_unlock(&em_tree->lock);
+ read_unlock(&em_tree->lock);
if (!em || IS_ERR(em)) {
kfree(failrec);
@@ -4069,11 +4069,11 @@ struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
int compressed;
again:
- spin_lock(&em_tree->lock);
+ read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, len);
if (em)
em->bdev = root->fs_info->fs_devices->latest_bdev;
- spin_unlock(&em_tree->lock);
+ read_unlock(&em_tree->lock);
if (em) {
if (em->start > start || em->start + em->len <= start)
@@ -4264,7 +4264,7 @@ insert:
}
err = 0;
- spin_lock(&em_tree->lock);
+ write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
/* it is possible that someone inserted the extent into the tree
* while we had the lock dropped. It is also possible that
@@ -4304,7 +4304,7 @@ insert:
err = 0;
}
}
- spin_unlock(&em_tree->lock);
+ write_unlock(&em_tree->lock);
out:
if (path)
btrfs_free_path(path);
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index c04f7f21260..4adab903fc2 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2646,9 +2646,9 @@ int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key)
lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
while (1) {
int ret;
- spin_lock(&em_tree->lock);
+ write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
- spin_unlock(&em_tree->lock);
+ write_unlock(&em_tree->lock);
if (ret != -EEXIST) {
free_extent_map(em);
break;
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index a7e53773e74..d2358c06bbd 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1749,9 +1749,9 @@ static int btrfs_relocate_chunk(struct btrfs_root *root,
* step two, delete the device extents and the
* chunk tree entries
*/
- spin_lock(&em_tree->lock);
+ read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, chunk_offset, 1);
- spin_unlock(&em_tree->lock);
+ read_unlock(&em_tree->lock);
BUG_ON(em->start > chunk_offset ||
em->start + em->len < chunk_offset);
@@ -1780,9 +1780,9 @@ static int btrfs_relocate_chunk(struct btrfs_root *root,
ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
BUG_ON(ret);
- spin_lock(&em_tree->lock);
+ write_lock(&em_tree->lock);
remove_extent_mapping(em_tree, em);
- spin_unlock(&em_tree->lock);
+ write_unlock(&em_tree->lock);
kfree(map);
em->bdev = NULL;
@@ -2294,9 +2294,9 @@ again:
em->block_len = em->len;
em_tree = &extent_root->fs_info->mapping_tree.map_tree;
- spin_lock(&em_tree->lock);
+ write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
- spin_unlock(&em_tree->lock);
+ write_unlock(&em_tree->lock);
BUG_ON(ret);
free_extent_map(em);
@@ -2491,9 +2491,9 @@ int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
int readonly = 0;
int i;
- spin_lock(&map_tree->map_tree.lock);
+ read_lock(&map_tree->map_tree.lock);
em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
- spin_unlock(&map_tree->map_tree.lock);
+ read_unlock(&map_tree->map_tree.lock);
if (!em)
return 1;
@@ -2518,11 +2518,11 @@ void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
struct extent_map *em;
while (1) {
- spin_lock(&tree->map_tree.lock);
+ write_lock(&tree->map_tree.lock);
em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
if (em)
remove_extent_mapping(&tree->map_tree, em);
- spin_unlock(&tree->map_tree.lock);
+ write_unlock(&tree->map_tree.lock);
if (!em)
break;
kfree(em->bdev);
@@ -2540,9 +2540,9 @@ int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
struct extent_map_tree *em_tree = &map_tree->map_tree;
int ret;
- spin_lock(&em_tree->lock);
+ read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, logical, len);
- spin_unlock(&em_tree->lock);
+ read_unlock(&em_tree->lock);
BUG_ON(!em);
BUG_ON(em->start > logical || em->start + em->len < logical);
@@ -2604,9 +2604,9 @@ again:
atomic_set(&multi->error, 0);
}
- spin_lock(&em_tree->lock);
+ read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, logical, *length);
- spin_unlock(&em_tree->lock);
+ read_unlock(&em_tree->lock);
if (!em && unplug_page)
return 0;
@@ -2763,9 +2763,9 @@ int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
u64 stripe_nr;
int i, j, nr = 0;
- spin_lock(&em_tree->lock);
+ read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, chunk_start, 1);
- spin_unlock(&em_tree->lock);
+ read_unlock(&em_tree->lock);
BUG_ON(!em || em->start != chunk_start);
map = (struct map_lookup *)em->bdev;
@@ -3053,9 +3053,9 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
logical = key->offset;
length = btrfs_chunk_length(leaf, chunk);
- spin_lock(&map_tree->map_tree.lock);
+ read_lock(&map_tree->map_tree.lock);
em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
- spin_unlock(&map_tree->map_tree.lock);
+ read_unlock(&map_tree->map_tree.lock);
/* already mapped? */
if (em && em->start <= logical && em->start + em->len > logical) {
@@ -3114,9 +3114,9 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
map->stripes[i].dev->in_fs_metadata = 1;
}
- spin_lock(&map_tree->map_tree.lock);
+ write_lock(&map_tree->map_tree.lock);
ret = add_extent_mapping(&map_tree->map_tree, em);
- spin_unlock(&map_tree->map_tree.lock);
+ write_unlock(&map_tree->map_tree.lock);
BUG_ON(ret);
free_extent_map(em);