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yaml
---
r: 285952
b: refs/heads/master
c: 1bb9190
h: refs/heads/master
v: v3
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Alexandre Oliva authored and Chris Mason committed Jan 8, 2012
1 parent 010a208 commit 0c2f2fc
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Showing 2 changed files with 50 additions and 64 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: fc7c1077ceb99c35e5f9d0ce03dc7740565bb2bf
refs/heads/master: 1bb91902dc90e25449893e693ad45605cb08fbe5
112 changes: 49 additions & 63 deletions trunk/fs/btrfs/free-space-cache.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2283,23 +2283,23 @@ u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group,
struct btrfs_free_space *entry,
struct btrfs_free_cluster *cluster,
u64 offset, u64 bytes, u64 min_bytes)
u64 offset, u64 bytes,
u64 cont1_bytes, u64 min_bytes)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
unsigned long next_zero;
unsigned long i;
unsigned long search_bits;
unsigned long total_bits;
unsigned long want_bits;
unsigned long min_bits;
unsigned long found_bits;
unsigned long start = 0;
unsigned long total_found = 0;
int ret;
bool found = false;

i = offset_to_bit(entry->offset, block_group->sectorsize,
max_t(u64, offset, entry->offset));
search_bits = bytes_to_bits(bytes, block_group->sectorsize);
total_bits = bytes_to_bits(min_bytes, block_group->sectorsize);
want_bits = bytes_to_bits(bytes, block_group->sectorsize);
min_bits = bytes_to_bits(min_bytes, block_group->sectorsize);

again:
found_bits = 0;
Expand All @@ -2308,7 +2308,7 @@ static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group,
i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, i + 1)) {
next_zero = find_next_zero_bit(entry->bitmap,
BITS_PER_BITMAP, i);
if (next_zero - i >= search_bits) {
if (next_zero - i >= min_bits) {
found_bits = next_zero - i;
break;
}
Expand All @@ -2318,24 +2318,18 @@ static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group,
if (!found_bits)
return -ENOSPC;

if (!found) {
if (!total_found) {
start = i;
cluster->max_size = 0;
found = true;
}

total_found += found_bits;

if (cluster->max_size < found_bits * block_group->sectorsize)
cluster->max_size = found_bits * block_group->sectorsize;

if (total_found < total_bits) {
i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, next_zero);
if (i - start > total_bits * 2) {
total_found = 0;
cluster->max_size = 0;
found = false;
}
if (total_found < want_bits || cluster->max_size < cont1_bytes) {
i = next_zero + 1;
goto again;
}

Expand All @@ -2351,23 +2345,23 @@ static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group,

/*
* This searches the block group for just extents to fill the cluster with.
* Try to find a cluster with at least bytes total bytes, at least one
* extent of cont1_bytes, and other clusters of at least min_bytes.
*/
static noinline int
setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
struct btrfs_free_cluster *cluster,
struct list_head *bitmaps, u64 offset, u64 bytes,
u64 min_bytes)
u64 cont1_bytes, u64 min_bytes)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct btrfs_free_space *first = NULL;
struct btrfs_free_space *entry = NULL;
struct btrfs_free_space *prev = NULL;
struct btrfs_free_space *last;
struct rb_node *node;
u64 window_start;
u64 window_free;
u64 max_extent;
u64 max_gap = 128 * 1024;

entry = tree_search_offset(ctl, offset, 0, 1);
if (!entry)
Expand All @@ -2377,8 +2371,8 @@ setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
* We don't want bitmaps, so just move along until we find a normal
* extent entry.
*/
while (entry->bitmap) {
if (list_empty(&entry->list))
while (entry->bitmap || entry->bytes < min_bytes) {
if (entry->bitmap && list_empty(&entry->list))
list_add_tail(&entry->list, bitmaps);
node = rb_next(&entry->offset_index);
if (!node)
Expand All @@ -2391,12 +2385,9 @@ setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
max_extent = entry->bytes;
first = entry;
last = entry;
prev = entry;

while (window_free <= min_bytes) {
node = rb_next(&entry->offset_index);
if (!node)
return -ENOSPC;
for (node = rb_next(&entry->offset_index); node;
node = rb_next(&entry->offset_index)) {
entry = rb_entry(node, struct btrfs_free_space, offset_index);

if (entry->bitmap) {
Expand All @@ -2405,26 +2396,18 @@ setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
continue;
}

/*
* we haven't filled the empty size and the window is
* very large. reset and try again
*/
if (entry->offset - (prev->offset + prev->bytes) > max_gap ||
entry->offset - window_start > (min_bytes * 2)) {
first = entry;
window_start = entry->offset;
window_free = entry->bytes;
last = entry;
if (entry->bytes < min_bytes)
continue;

last = entry;
window_free += entry->bytes;
if (entry->bytes > max_extent)
max_extent = entry->bytes;
} else {
last = entry;
window_free += entry->bytes;
if (entry->bytes > max_extent)
max_extent = entry->bytes;
}
prev = entry;
}

if (window_free < bytes || max_extent < cont1_bytes)
return -ENOSPC;

cluster->window_start = first->offset;

node = &first->offset_index;
Expand All @@ -2438,7 +2421,7 @@ setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,

entry = rb_entry(node, struct btrfs_free_space, offset_index);
node = rb_next(&entry->offset_index);
if (entry->bitmap)
if (entry->bitmap || entry->bytes < min_bytes)
continue;

rb_erase(&entry->offset_index, &ctl->free_space_offset);
Expand All @@ -2460,7 +2443,7 @@ static noinline int
setup_cluster_bitmap(struct btrfs_block_group_cache *block_group,
struct btrfs_free_cluster *cluster,
struct list_head *bitmaps, u64 offset, u64 bytes,
u64 min_bytes)
u64 cont1_bytes, u64 min_bytes)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct btrfs_free_space *entry;
Expand All @@ -2485,7 +2468,7 @@ setup_cluster_bitmap(struct btrfs_block_group_cache *block_group,
if (entry->bytes < min_bytes)
continue;
ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
bytes, min_bytes);
bytes, cont1_bytes, min_bytes);
if (!ret)
return 0;
}
Expand All @@ -2499,7 +2482,7 @@ setup_cluster_bitmap(struct btrfs_block_group_cache *block_group,

/*
* here we try to find a cluster of blocks in a block group. The goal
* is to find at least bytes free and up to empty_size + bytes free.
* is to find at least bytes+empty_size.
* We might not find them all in one contiguous area.
*
* returns zero and sets up cluster if things worked out, otherwise
Expand All @@ -2515,31 +2498,32 @@ int btrfs_find_space_cluster(struct btrfs_trans_handle *trans,
struct btrfs_free_space *entry, *tmp;
LIST_HEAD(bitmaps);
u64 min_bytes;
u64 cont1_bytes;
int ret;

/* for metadata, allow allocates with more holes */
/*
* Choose the minimum extent size we'll require for this
* cluster. For SSD_SPREAD, don't allow any fragmentation.
* For metadata, allow allocates with smaller extents. For
* data, keep it dense.
*/
if (btrfs_test_opt(root, SSD_SPREAD)) {
min_bytes = bytes + empty_size;
cont1_bytes = min_bytes = bytes + empty_size;
} else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
/*
* we want to do larger allocations when we are
* flushing out the delayed refs, it helps prevent
* making more work as we go along.
*/
if (trans->transaction->delayed_refs.flushing)
min_bytes = max(bytes, (bytes + empty_size) >> 1);
else
min_bytes = max(bytes, (bytes + empty_size) >> 4);
} else
min_bytes = max(bytes, (bytes + empty_size) >> 2);
cont1_bytes = bytes;
min_bytes = block_group->sectorsize;
} else {
cont1_bytes = max(bytes, (bytes + empty_size) >> 2);
min_bytes = block_group->sectorsize;
}

spin_lock(&ctl->tree_lock);

/*
* If we know we don't have enough space to make a cluster don't even
* bother doing all the work to try and find one.
*/
if (ctl->free_space < min_bytes) {
if (ctl->free_space < bytes) {
spin_unlock(&ctl->tree_lock);
return -ENOSPC;
}
Expand All @@ -2553,10 +2537,12 @@ int btrfs_find_space_cluster(struct btrfs_trans_handle *trans,
}

ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
bytes, min_bytes);
bytes + empty_size,
cont1_bytes, min_bytes);
if (ret)
ret = setup_cluster_bitmap(block_group, cluster, &bitmaps,
offset, bytes, min_bytes);
offset, bytes + empty_size,
cont1_bytes, min_bytes);

/* Clear our temporary list */
list_for_each_entry_safe(entry, tmp, &bitmaps, list)
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